The afternoon of August 13th 2021 provided a very favorable environment for thunderstorms with significant damaging winds. Temps were in the mid-upper 90s to near 100 with dew points low-mid 70s leading to an extremely unstable airmass with 3,000-4,000 j/kg of CAPE. When combined with very steep lapse rates and high DCAPE, any storm that formed would likely produce damaging winds.  And that was certainly the case, with widespread wind damage being observed across the area as seen in the above image where each W represents a wind damage report. 

One storm in particular was especially intense, producing a destructive microburst in the area of Clarksville into Columbia. While winds gusts ranged from 50-60mph across most of Howard county, the core of this microburst produced winds of 80-90mph, knocking down dozens upon dozens of trees and many powerlines. There were countless branches down on many roads and power was out for more than 48 hours in some areas. I took the images below the next day along Ten Oaks Road and surrounding neighborhoods. The NWS issued a severe thunderstorm warning in advance of this, warning of the likelihood that winds would exceed 70mph.

Just another reminder that it does NOT take a tornado to do major wind damage and to create life threatening conditions. 

Now that Debby has passed, this will be a fairly brief summary of the impact she delivered across the central portions of the state from Thursday into Friday.

Rainfall wise, a widespread 3-5" fell generally along and west of the I-95 corridor especially across Montgomery, Howard, Carroll, and Frederick counties which is where multiple bands of rain with rates of 3-4" per hour occurred. Unfortunately, this resulted in numerous instances of flash flooding, including at my house which has only happened on 2 other occasions in the 3 years living here. Further east, some areas saw as little as just a quarter inch of rain, but most saw 1-2" along the I-95 and just east. The lowest amounts were along the bay shore. 

As far as wind gusts go, most areas saw winds in the 30-40mph range, with a few 50+mph gusts being recorded along the bay where there is less friction. Because these winds were from the SSE, they also produced significant coastal flooding that exceeded the expectations of most forecasts, with 3-5 foot tidal anomalies (above normal) being observed. Inland, the combination of heavily saturated soils, drought stress, and wind gusts of 30-40mph produced scattered instances of wind damage to trees as well as several thousand power outages.

Thankfully, we had no confirmed tornadoes in Maryland, however almost every downpour had rotation in it thanks to copious amounts of wind shear. Hence the long duration tornado watch (nearly 18 hours in some areas). This may have been the longest duration tornado watch in our area on record. However, several tornadoes did occur nearby from Debby, including 2 in northern VA, 1 in the WV panhandle, one in northern DE, and one in Harrisburg PA. 

There was a swath of minor tree damage in the southern portion of Mount Airy along Florence Road and Mullinix Mill Road, north to Watersville Road where a few dead trees were downed and branches were broken off. This lined up with where a weak velocity couplet tracked and a tornado warning was in effect. However after a good discussion with the NWS in Sterling VA, it was determined that this damage was due to strong straight line winds combined with heavily saturated soils loosening the root balls and weakening the trees. While sheltering in my basement, I peeked at our storm camera (we use this camera to watch storms from our shelter) and saw a rotating funnel cloud passing over our neighborhood here in Mount Airy. Luckily it never touched down but that was WAY too close for comfort. The image below was taken outside of my neighborhood consisting of a downed tree and  few small branches.

Senior Forecaster Jack

Above is a map of all of the confirmed tornadoes and their approximate tracks. Data was gathered from the storm surveys completed by NWS Sterling. In total, 9 tornadoes have been confirmed throughout Carroll, Montgomery, Howard, Washington and Baltimore counties as well as Baltimore City.
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This is the largest tornado outbreak in Maryland since 2012 not related to a tropical system.

More detailed information for each of these tornadoes can be found below. Blue tracks and triangles equal EF0 damage, and green tracks and triangles indicate EF1 damage. Note, the Eldersburg track should be green as it was rated EF1. In addition, the Boonsboro tornado was rated EFU for unknown, so its track is grey.​

At approximately 7:59pm, an EF1 tornado touched down in eastern Carroll county on the NW side of Eldersburg. Major tree damage and some structural damage occurred along its path. The tornado had peak winds estimated at 110mph, was on the ground for more than 4 miles, and had a peak width of about 100 yards.

Damage was first noted on Tanglewood Drive and Covington Court where trees were blown down and "pointed in different directions" according to NWS. As the tornado continued northeast, more significant damage occurred on Barthollows road and Sarah Drive where dozens of trees sustained significant damage. Some trees fell onto at least one house in this area. Damage to a home in the form of loss of siding and shingles occurred near Sun Berry court. On cherry tree lane, hundreds of trees were blown down and snapped at several residences with total mow downs of forest sections noted in some areas.

On the north side of Liberty reservoir, a large swath of softwood trees were snapped and uprooted. Most trees in the path of the tornado at this location were blown down or severely damaged. Some debarking of trees also occurred. At Faith Family Church in Gamber, Foots Forecast Viewer Maria was kind enough to give me a tour of the damage. She showed me hundreds of downed trees behind the church, many of which were over 2 feet in diameter. Her house also sustained shingle and flashing damage and a large walnut tree was uprooted in her yard. The tornado continued NE and destroyed a barn on Providence lane as well as removing half the roof off a nearby house.

While the official rating was EF1, it was only 1 mph away from being an EF2. This is the strongest tornado of this outbreak and the strongest to hit Carroll county since 2018 when an EF2 struck Mount Airy.

At 8:31pm, an EF1 tornado touched down in Columbia impacting the Long Reach Village Center. This tornado had winds of 95mph, a path length of 1 mile, and path width of 75 yards. 

The first indication of tornado related damage was on Phelps Luck Drive. A concentrated area of tornado damage occurred on High Tor Hill where it intersects with Tamar drive. This is where numerous trees were snapped, sheared off, and uprooted. Some trees fell onto homes and cars which resulted in structural damage. Roofing was also peeled off a townhouse in this area. In total, there were about 2 dozen damaged trees in this section of Columbia. The tornado continued to move ENE for a short time before lifting. But not before resulting in additional damage on Hayshed lane and Waterloo road where more trees were snapped and uprooted. The tornado lifted at 8:33pm. 

At 7:01pm, an EF1 tornado touched down in Elmer making a 6.6 mile long path across west central Montgomery County through Poolesville. The tornado was a high end EF1 with maximum winds of 10mph and a maximum width of 

The first damage was note by Montgomery county EMA as multiple trees down just east of the Potomac river including on Elmer school road and River road. Trees and branches were blown down on West Willard Rad as well. At Tudor Farm, about 2 dozen pine trees were snapped and uprooted, and barn doors were reported to  have collapsed. Further east towards the end of the tornadoes path, significant tree damage occurred on White Ground road where several trees were snapped and some were debarked indicative of winds over 100mph. The tornado lifted at about 7:21pm. 

At 7:29pm, video recording of a tornado passing over Indian Grass drive was recorded. This marks the start of this EF1 tornado that contained winds of 95mph, a path width of 150 yards, and path length of 15.23 miles. 

Minimal damage occurred to trees on Highway 119 with branches being reported down. Further east, the damage was much more significant with hardwood trees being snapped along George Street north of Gaithersburg High School. Huge oak trees were uprooted, and one fell onto a house on Tulip drive, and at least 1 large tree was uprooted on Rolling Road. According to NWS, there were also several reports of downed branches in the Olney area as well as video footage of the tornado on the ground. In sandy spring, the fire department reported numerous trees down in the area. And along Westlawn drive in Ashton, numerous trees were down blocking the road. This is where the tornado was believed to have lifted at about 8:03pm.

A very brief but still quite strong tornado touched down in Middle River at 8:57pm. The tornado was about 110 yards wide and traveled 1 mile with winds of 105mph making this an EF1 tornado. 

The first instances of damage was reported near Martin State Airport in the Williams Estates area which is a mobile home park. Most of the damage consisted of the removal of underpinning from single and double wide mobile homes. This also included mobile homes on Wagon Train Road and Roundup Road. In addition to this structural damage, several instances of tree damage occurred as well. The most significant tree damage happened on Dahlia lane and Roundup Road. It was in this area that more significant structural damage occurred including windows being blown out on several mobile homes. One one mobile home, peices of a shed were impaled into the side of the house due to the force of the wind.

Similar damage was noted further downstream with more underpinning and shingle damage occurring as the path widened and the tornado began to weaken. It was after this point that the tornado dissipated at approximately 8:58pm.

At approximately 5:41pm, a brief EF-U tornado was seen dissipating over an open field. As no damage was observed, this tornado was rated EF-U where U stands for unknown. Had any damage occurred, it likely would have been very minor with winds less than 60mph in this tornado. Because there was no damage, no official wind speed or path width could be determined. 

At 9:01pm, a very brief EF-0 tornado touched down in southeastern Baltimore City near Canton. The tornado had maximum winds of 70mph, a path width of 90 yards, and was only on the ground for less than half a mile. 

The tornado made its touchdown near Anchorage Promenade Park confirmed via video footage. Damage was fairly sparse including small branches thrown around on Hudson Street and south Luzerne avenue. At the Hatton senior center, several large branches were snapped and trashcans were blown around. And along Foster avenue, a large tree was blown down and an awning was heavily damaged. After bending a stop sign, the tornado lifted before hitting the Highlandtown Neighborhood.

ATHOLTON AREA: Minor damage occurred on a few roads in the Atholton area of Columbia including downed tree branches and damage to the athletic field at the high school. While this may have been indicative of a brief tornado touchdown, there was not enough evidence to support this. For this reason, NWS did not confirm a tornado in this area as the damage was too spotty and not concentrated.

WEST FREINDSHIP AREA: Earlier in the afternoon, a weak but noticeable area of rotation may have produced a very brief and weak tornado near West friendship. When I went to look for damage, it consisted of a few downed trees and branches, but there was no clear tornadic signature in the damage. For this reason, it is unlikely that NWS will be able to confirm a tornado touched down here.

This is not official NWS information. Please refer to official NWS surveys for official details. The above information in the "other areas" section of this article is our opinions and does not reflect that of the NWS.

We want to give a shout out to the incredible meteorologists at NWS Sterling for issuing the advanced tornado warnings ahead of these storms. This no doubt prevented any fatalities from occurring. We  also want to give a shoutout to all our local broadcast meteorologists at WBAL, WJZ, WMAR, FOX5, WUSA9, WJLA, and NBC4. They all did an amazing job covering this event that frankly caught us all off guard. 

Final note: All information rom each individual tornado that was confirmed came from the NWS surveys which can be found here https://mesonet.agron.iastate.edu/wx/afos/p.php?pil=PNSLWX&e=202406131533

​Forecaster Jack and the CMD team

A very active pattern set up in early and mid January with multiple impactful storm systems back to back. The strongest and most impactful storm occurred on January 9th and 10th with widespread inland and coastal flooding as well as winds in excess of 50-60mph across the area. Below is a recap of the impacts across central Maryland. 

A very impressive amount of rainfall in just 12 hours or so occurred across a wide swath of the east coast. In general, 2-4 inches fell in central Maryland with isolated amounts in excess of 4" observed north and east of Baltimore. 
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This was thanks to a record strong low level jet and moisture transport across the region. PWATs surged to 3-4 standard deviations above normal which is extreme for this time of year in particular, and means the atmosphere was fully loaded with moisture just waiting to be wrung out on top of us. The ground was already extremely saturated due to previous heavy rain events, and with rainfall rates of an inch per hour, it was clear this would bring widespread flooding to the area.

Some of the more impressive rainfall reports were 3.56" in Damascus, 4.20" in Long Green, and 4.40" in Abingdon. 

The wind with this system was extremely impressive with some aspects of it unprecedented for our area. Widespread wind gusts of 50-55mph were recorded all across central Maryland, with gusts as high as 60-65mph along the shore of the Bay. This prompted a rare high wind warning for all areas along and east of I-95. With the combination of extremely saturated and in some cases flooded soils, these winds resulted in widespread wind damage including downed trees and powerlines. I actually had to call the fire department to my own street as powerlines were snapped. 

Some of the most impressive wind gusts were 55mph in Owings Mills, 55mph in College Park, 53mph at BWI, and 54mph at Camp David. Locally higher wind gusts occurred along the bay shore. This also resulted in a substantial amount of power outages, surpassing the amount we saw from the August 7th severe weather outbreak.

The main reason behind the damaging winds was a historically strong wind feild both in the low levels and upper levels of the atmosphere. 

Winds at 200mb were running between 120 and 140 kts which may be considered a sting jet (depending on who you ask). This magnitude of winds is almost unheard of in our area. One exception may be February 2020 when the upper level jet streak had winds in excess of 150kts. NWS confirmed this was the 2nd strongest wind field to ever be recorded in our area. Closer to the surface within the low level jet, winds averaged 50-80kts, with some model output suggesting 90kts of sustained winds (image above of the HRRR models 850mb winds), which would equate to about 100mph just a few thousand feet off the ground. 

The image above shows the sounding taken that evening. Winds were extreme throughout the entire atmospheric column with a deep mixing layer. This allowed a lot of this wind to be transferred to the surface when combined with a tight pressure gradient as the low pressure system deepened to 980mb to our NW. Heavy rainfall rates also assisted in good downward momentum transfer of these winds aloft to the surface. 

You will also notice very strong low level veering of the winds and a fairly impressive hodograph. Its a good thing there wasn't any instability during this time, or else we would also have been dealing with a substantial tornado event as well. 

I took this image above around 4pm that day of a creek a few streets down from me. This creek usually had a depth of about 1-2 feet, but rose to an estimated depth of 4-5 feet, nearly exceeding its banks. The water flow was much more rapid than normal with debris such as logs floating down in the current. 

Overall, it was one of the most impactful storms we have seen around here in a long time, prompting schools to close early, roads to be blocked by flooding and downed trees/power lines, and power to be out for several days in some areas. Hopefully we don't have another storm like this anytime soon, as even I, someone who loves weather, doesn't like to see this kind of widespread damage. 

On the afternoon and evening of June 8th, multiple rounds of thunderstorms produced widespread heavy rain and flash flooding across central Maryland. In addition, an area of intense rotation associated with a supercell embedded within a cluster of thunderstorms resulted in significant wind damage over Columbia. 

At 8:27pm, an area of weak rotation began to develop south of Columbia by about 3 miles (above image). At this point, it wasn't of concern as the environment wasn't super favorable for tornadoes, but I began to have an increased sense of awareness and kept a closer eye on the storm. For now, the main threat remained very heavy rain and ongoing flash flooding which prompted an additional flash flood warning. 

By 8:29pm, the rotation had begun to quickly intensify as it likely was interacting with an outflow boundary from a prior storm (see above image). At this point, I began to get a bit more concerned and so I started writing a post to our Facebook page that was going to tell people in the area "this storm is starting to concern me due the intensifying rotation and a tornado warning is likely to be issued shortly". 

BUT.... before I could finish writing that post, the next radar scan came in at 8:32pm and it became immediately clear a tornado was either ongoing or about to hit the east side of Columbia and a tornado warning was issued for eastern Howard County. There was a clear velocity couplet and hook echo as well (See above image) showing a clear tornado signature from a radar perspective. 

Above you can see the NWS report of major wind damage where the velocity couplet was most intense. The most intense damage occurred from near Atholton to Oakland mills, the Cradlerock area, and also near Kendall ridge. I drove through these areas and to me, it looked like high end EF1 tornado damage (winds around 100mph). But the official report from NWS was that this was a microburst of 75mph winds and NOT a tornado. To produce tree damage of this magnitude, it should have taken winds over 85mph, not a peak of 75mph. That doesn't seem like a big difference, but remember that damage increases exponential with wind, not linearly. So an additional 10mph can make a major difference in the damage. 

Forecaster Jack

We are no strangers to severe weather in the mid atlantic. Its common for us to end our heatwaves with significant severe weather events in the form of damaging winds. However, this storm was different. With extremely unstable air due to temps well into the mid 90s and even some wind shear which isnt too common this time of year, we knew there would be significant severe weather somewhere in the region and a severe thunderstorm watch was issued in the early afternoon. 

Just before 3:30pm, scattered thunderstorms began to develop over west central MD and northern VA in a very unstable airmass. At this point, the storms were sub severe, but contained heavy rain and gusty winds. 

Just before 4pm, the storms rapidly intensified as they interacted with a highly unstable airmass with 3,000-4,000 j/kg of CAPE and some modest wind shear as well. The strongest storm was located over western Montgomery county at this point and was quickly moving towards the metro. Severe thunderstorm warnings were quickly issued and eventually upgraded to considerable with wind gusts over 70mph. Additional storms formed over northern MD, but they did not become severe due to weaker forcing in that area. 

At around 4:30pm the storms reached areas just to the NW of I-95 and continued to organize into a squall line producing widespread wind damage across Montgomery and Howard counties. At this point, severe thunderstorm warnings blanketed the I-95 corridor warning of wind gusts as high as 70mph. The storms continued to produce widespread wind damage. 

At approximately 4:50pm, the severe thunderstorms reached peak intensity right as they were in the heart of the DC metro area. At this point, they were producing wind gusts of 80-90mph and severe thunderstorm warnings were upgraded to destructive as NWS urged residents to shelter like a tornado was occurring. These storms were producing tremendous wind damage in downtown DC not just to trees, but also to structures with several buildings suffering roof and siding damage. Thousands of trees were also blown down. 

At 5:12pm, the worst of the wind had cleared downtown DC, but now put southern PG county under the gun as the 80mph winds became even more widespread. In PG county, there were so many downed trees on the BW parkway that it had to be closed for 4 days. Additional destructive tagged severe thunderstorm warnings blanketed south central MD into southern MD. An 84mph wind gust was recorded in downtown DC, which is the strongest wind measured since the 2012 derecho.

So what have we learned from this event?
1: When temps are in the mid 90s and a cold front is forecasted to come through, expect severe weather, potentially significant, somewhere. 
2: You do not need a tornado to produce major and life threatening wind damage and when a destructive tagged severe thunderstorm warning is issued, seek immediate shelter like you would for a tornado warning. 

On December 23rd 2022, an extremely powerful low pressure system tracked over the great lakes, intensifying rapidly to at least 968mb, which is equivalent to the pressure of a category 2 hurricane. This resulted in a very tight pressure gradient over our region, resulting in damaging winds, and a powerful cold front that dropped temperatures so rapidly that it caused a flash freeze. This storm was one of the most impactful storms in recent history given that it was during an extremely busy travel period, and that it was impacting the eastern half of the country. 

The combination of intense cold air advection, good mixing, and a very tight pressure gradient overhead led to a prefect set up for damaging winds. Widespread wind gusts of 50-60mph were recorded across the area with some gusts between 60 and 70mph. The strongest gust recorded in central MD was 68mph in east central Frederick county. Other impressive gusts include 63mph at BWI, 57mph in Ballenger Creek 58mph in Owings Mills, and 55mph in Manchester. 

These winds combined with saturated soil resulted in widespread wind damage with many trees coming down as well as powerlines. In addition, several reports of structural damage were observed. The most significant that we were aware of was in Westminster when a portion of a roof was blown off a shopping center. Unfortunately, there was 1 fatality due the wind, in Frederick county when a tree fell onto a mans car. 

For the first time in many years, a wind chill advisory (shown in light blue area wide above) had to be issued by NWS due to the forecast of low temperatures between -5 and +10 degrees, with wind chills of -10 to -20 degrees. This life threatening cold is not something we see very often around here and was a real shock to the system for many people. As cold as it was here, places in the Midwest dropped as much as 50 degrees in just a few hours, with wind chills as much as 50 degrees BELOW ZERO!

Some record low temperatures were set as well. The wind chills were extremely impressive across the region as well. Mount airy had a wind chill of -14, BWI of -12, Owings Mills of -17, Manchester of -19, and Glenelg of -20! These temperatures resulted in a flash freeze which turned any remaining moisture from rain the previous day immediately into a sheet of ice resulting in hazardous travel. In fact it got so cold that the door knobs on the INSIDE side of my doors on my house were covered in frost...I have never experienced anything like that before.

​Forecaster Jack

On December 19th 2009, a major snowstorm buried our region in FEET of snow area wide. This was the result of a powerful coastal storm we know as a Nor'easter that tracked up the east coast. The storm bombed out bringing heavy snow and strong winds to the Mid Atlantic. 

Across our area, many locations saw 10-20 inches of snow, with some seeing up to 30 inches.
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BWI: 18 inches
Crownsville: 24.2 inches
Hampton: 22 inches
Baltimore: 19 inches
Manchester: 19 inches
Westminster: 19 inches
Frederick: 22 inches
Emmitsburg: 19 inches
Columbia: 23 inches
Elkridge: 21 inches
Damascus: 26 inches
Rockville: 20 inches
Bowie: 21 inches
Laurel: 19.1 inches

On the evening of September 24th, 2001, a catastrophic EF5 (F3 on the old scale) tornado plowed through Prince Georges and Howard counties resulting in unimaginable damage, and unfortunately loss of life. 

This tornado started as a supercell in the DC metro. Broad rotation was occurring and there was a tornado warning already in effect well ahead of the time of touchdown. Below is a radar image of the storm crossing out of DC into PG county just prior to when the tornado touched down. This is when the rotation rapidly began to strengthen.​

The tornado continued tracking NNE and made a direct impact to the UMD College Park Campus. Here, severe damage occurred and 2 students were tragically killed as their car was lofted into the tornado. Severe damage/total destruction occurred further north as the tornado tracked into Beltsville, approximately 1 mile from where my dad was a work sheltering in an underground garage with his coworkers. This is approximately the time when him and my mom (who was at her apartment in Columbia) lost contact as cell towers were toppled by the tornado. This is likely when the tornado reached its peak intensity shown by the remarkably strong velocity couplet on radar. 

From there, the tornado made a bit of a northward turn and crossed into Howard county where it weakened into an EF2 in laurel, and eventually into an EF1 in Columbia. Damage was noted in Laurel (where a townhouse complex was heavily damaged), Savage, and in Columbia (where trees were blown down), but was nowhere near as severe as what had just occurred further south. The tornado lifted a few miles before striking my moms apartment near Mt Hebron. Below is a radar image showing the tornadic circulation as it crosses out of Savage and into the southern part of Columbia.

After the damage surveys were completed, the tornado was rated F3 (EF5 on the new scale) with winds of 200mph. It was estimated to be between 100 and 200 yards wide and traveled a path of approximately 17.5 miles. This makes it one of the longest tracked tornadoes in MD history, and one of the strongest as well. This tornado produced over $100 million in damage just in Prince Georges county alone. 

Statistical data and damage information credit goes to NWS Sterling.

Forecaster Jack

On June 1st, 1012, a significant tornado outbreak occurred across the Mid-Atlantic with 11 tornadoes touching down in central Maryland alone. This was due to a highly favorable atmosphere in place, which prompted SPC to issue a rare moderate risk (level 4/5)  of severe weather. Below you can see a map of all the tornadoes in our area from this day. Outlined in green were rated EF0, while those outlined in blue were rated EF1.

Wind shear was running around 50kts, with 0-1km SRH (Storm Relative Helicity) in excess of 290 m2/s2. This meant that any thunderstorm that tapped into that wind shear would have a strong likelihood of rotating and producing a tornado. Lapse rates were fairly week, but there was a decent amount of CAPE for storms to work with which led to fairly quick development during the afternoon. Given these favorable conditions, numerous supercells with tornadoes developed across our region. The image below is a sounding from that day from NWS Sterling. It shows a very favorable wind profile for tornadoes, which we don't see very often around here. ​

TORNADO LIST BY COUNTY:
MONTGOMERY:

• Poolesville- EF0 70mph
• Damascus #1- EF0 70mph
• Damascus #2- EF0 75mph

HOWARD:

• South Columbia- EF0 85mph

CARROLL:

• Mount Airy #1- EF0 75mph
• Mount Airy #2- EF1 100mph
• NW of Finksburg- EF1 90mph

PRINCE GEORGES:

• Springdale- EF0 65mph

ANNE ARUNDEL:

• S of Fort Meade- EF0 65mph
• Fort Meade to BWI- EF0 80mph

HARFORD:

• Fallston- EF1 100mph

Photo credit 1: tornadoarchive.com
Photo credit 2: NWS Sterling
Special thanks to Jen Narramore of Tornado Talk for help on finding wind speeds for these tornadoes!

An poorly forecasted and historic severe weather/tornado outbreak occurred across the mid atlantic during the morning rush hours on February 7th, 2020. 

The 2 main ingredients for a tornado event of this magnitude are very strong wind shear and high amounts of instability. The wind shear on this morning was incredibly strong, with over 400 m/s^2 of 0-1km storm relative helicity, and over 100 kts of 0-6km wind shear which is just off the charts. That is almost unheard of in our area. The surprising thing is that there was very low instability with cape coming in at less than 200 j/kg. That typically would not support an event of this magnitude in our area. However, the extreme shear and potent jet stream dynamics (200mph winds at 35,000 feet) were able to overcome the lack of instability and produce 5 tornadoes (4 in our viewing area) in maryland alone along with widespread wind damage. This many tornadoes in just one day is unprecedented in the state of MD for February.

Below is a map from the National Weather Service showing all the wind damage and tornado reports from that morning. 

The first tornado in our area occurred in Dickerson, which is in extreme southwestern Montgomery county. This tornado resulted in mainly tree damage, but 2 barns had significant roof damage as well. Additionally, a metal windmill tower was blown down. The final area of damage was noted at a farm house where numerous shingles were torn off the roof. This tornado was rated EF1 and had winds of 95mph. The tornado traveled only 1 mile and was on the ground for just 60 seconds (from 7:28am until 7:29am). The tornado was 150 yards wide.

The second tornado occurred just to the southeast of the first tornado, in Boyds. The tornado took down many trees, before striking a dog training facility. Here, several structures were damaged and a storage building was flattened. There were also 2 2x4 boards that were blown into 2 structures and impaled them. This tornado was rated EF0 and had winds estimated around 80mph. Again, this one was on the ground for only 1 minute and traveled 2.3 miles. This tornado was only 75 yard wide. 

A third tornado touched down in Monrovia which is in eastern Frederick county. Along its path, several structures were heavily damaged, including 2 barn structures that were flattened. After that, significant tree damage occured as the tornado traveled NE across I-70 and to the NW of Mount Airy, where many trees were blown down. The tornado was rated a mid range EF1 with 105mph winds. This tornado traveled 6 miles and was 150 yards wide. It was on the ground 7:44am until 7:40am. 

The final and longest track tornado occured in Westminster and tacked up into downtown Manchester resulting in intermittent damage along the way. There was a mix of tree and powerline damage in Westminster as well as roof and siding damage. The tornado traveled NE into Manchester where significant tree damage occurred. The tornado was rated EF1 with max winds of 90mph. It traveled 10.3 miles from 8:03am until 8:14am and was about 100 yards wide. 

Forecaster Jack

On the afternoon of May 2th 2018, multiple rounds of extremely heavy rain yet again tracked over central Howard county. These thunderstorms came after an already wet start to the year so the area was already primed for flooding. This was a fairly well forecasted event with a flash flood watch being issued earlier that morning many hours ahead of the rain. At 3:19pm, things began to rapidly worsen with a flood warning being issued. In total, over 1,100 911 calls were reported across howard county due to flooding or storm damage.

Below is a radar loop from 2:46pm until 4:26pm, when the first round of torrential rain enveloped Ellicott City. This immediately prompted the issuance of a flash flood warning, and the first wave of flash flooding. 

A second round of very heavy rain occured from about 4:30 until 6:15 seen in the radar loop below. This prompted an upgrade to a flash flood emergency as a second, more devastating wave of flooding swept through the city. at 5:41pm, this statement was issued by NWS:

"At 538 PM EDT, there have been numerous reports of significant flash flooding, roads flooded, streams flooded, and flood damage throughout the area. HEAVY RAIN HAS MOVED BACK INTO THIS AREA. THOSE CURRENTLY RESPONDING TO EARLIER FLASH FLOODING MUST SEEK HIGHER GROUND IMMEDIATELY AS A NEW ROUND OF FLOODING IS IMMINENT! THIS NEW FLOODING COULD BE MORE SIGNIFICANT THAN THE INITIAL ROUND! YOU MUST GO TO THE HIGHEST POSSIBLE LOCATION IMMEDIATELY AND STAY AWAY FROM ANYWHERE WHERE THERE IS WATER OR COULD BE WATER!!!

​ This is a FLASH FLOOD EMERGENCY for Ellicott City and Catonsville. This is a PARTICULARLY DANGEROUS SITUATION. SEEK HIGHER GROUND NOW!"

At 6:20pm, an even stronger worded flash flood emergency statement was issued :

"At 620 PM EDT, numerous reports of significant flash flooding have been reported, especially in Ellicott City. ANOTHER ROUND OF HEAVY RAIN IS MOVING BACK INTO THIS AREA. EVEN THOUGH RAIN HAS RECENTLY DECREASED, RESPONDERS AND LOCALS WHO ARE IN ELLICOTT CITY MUST RETURN TO HIGHER GROUND IMMEDIATELY! A THIRD ROUND OF FLOODING IS IMMINENT! IF YOU ARE NOT IN THE AREA, STAY AWAY! THIS IS A CATASTROPHIC AND LIFE-THREATENING EXTREMELY DANGEROUS SITUATION! YOU MUST TAKE ACTION NOW AND STAY AWAY FROM ANYWHERE WHERE WATER IS OR COULD BE'!"

Overall, rainfall amounts were similar to what occured in 2016, with a widespread 2-4" across the northern 2/3 of the county, with a localized area of 5-12" falling over Ellicott City.

The rainfall at the given time intervals were as follows:

1 min: 0.16"
5 min: 0.56"
10 min: 0.96"
15 min: 1.44"
30 min: 1.84" (from 3:53-4:22 and again from 5:20-5:50)
60 min: 2.68" (From 3:20-4:20) and 2.84" (From 5:00-6:00)
2 hr: 5.00"
3 hr: 6.56"

Unfortunately, one person, Eddison Hermond, age 39, was killed during the first wave of the flood while trying to help a woman who was seeking help. Many buildings were severely damaged, and some were destroyed and had to be rebuilt. Additionally, dozens of cars had flood damage as they were washed down the roads. Also of note, is that the Hudson branch has a flood stage at 247 feet. Water levels during this flood rose an additional 4-5 FEET topping major flood stage which is 260 feet.

Forecaster Jack

Photo/GIF credit 1, 2 , and 3: NWS Sterling

On Tuesday, October 26th, 2021, a low pressure system was located over the Ohio Valley region, which produced winds that blew into the Chesapeake Bay and tidal Potomac River from the Atlantic Ocean. This was followed by a similar system rising out of the Mississippi River Valley region on Friday, October 29th, 2021. This led to a prolonged period of onshore winds and one of the worst coastal flooding events in recent history.

The highest water levels from the event were measured along the tidal Potomac River near the Georgetown area in Washington, D.C. Friday afternoon, the water levels in this area was measured at 8.19 feet. Although this was not a record high water level for the location, a few other nearby areas did experience record high coastal flood waters. A water level measuring gauge in Dahlgren, Virginia set a record for highest recorded water level in the area late Friday morning, measuring in at 5.64 feet. Friday evening, the measuring gauge at Straits Point, Maryland also recorded a record high water level, at 4.90 feet. Around this same time, water levels also peaked at the measuring gauge in Solomons Island, Maryland along the Chesapeake Bay, reading 4.82 feet. 

​...Forecaster Zach...

Further south prior to the tornadoes, extensive straight line wind damage occurred between 4:30 and 5:30pm across Carroll and Baltimore counties but especially Carroll County. Hundreds of trees and dozens of power lines were blown down. A wind gust to 80mph was recorded in Middleburg, and wind gusts around 80-90mph blew down dozens of power lines onto cars in Westminster. Many areas in the pink circle on the Carroll County graphic had winds between 70 and 90mph. Winds were weaker further south, but still gusted between 50 and 60mph across central Maryland resulting in sporadic damage. A video of this storm can be found at this link from our very own Forecaster Joey.

​Hopefully this puts into perspective that we don’t need tornadoes to have life threatening weather and severe wind damage. 80mph straight line winds do just as much damage as a tornado will and you need to take it seriously and move to a shelter.

Forecaster Jack and the CMD team

For several days, the track of ida looked to go near or just to our north, putting us in a favorable position to see severe weather and flash flooding impacts. Given the time of year, it was still very warm with plenty of instability. So when you add in the copious wind shear and forcing from a decaying tropical system, it sets the stage for a significant weather event, which is exactly what happened. 

The first tornado of the day was an EF2 in Anne Arundel County. It paralleled Route 2 through the central parts of the county resulting in significant damage. In Annapolis, numerous trees and powerlines were snapped and blown down, with significant structural damage occurring a well. The tornado touched down at 2:01pm and traveled about 11.5 miles before lifting just north of Annapolis. Winds in this tornado were estimated to be about 125mph with a peak width of 200 yards. The radar data (left) could not have been any clearer that a tornado was occurring and NWS did a great job getting out an advanced warning. To the right, you'll see the NWS survey track. 

The next tornado was a much weaker yet still damaging EF0 in extreme southeastern Baltimore County around Edgemere. This tornado was produced by the same supercell that produced the stronger Annapolis tornado. It touched down at about 2:48pm and lifted at 3pm, leaving  damage path of about 7 miles long and only 75 yards wide. The tornado had winds of 85mph at its highest intensity and resulted in mainly tree damage across its path. 

Aside from the tornadoes, widespread flash flooding, some significant, also occurred. Multiple rounds of torrential rain and thunderstorms atop already saturated grounds was a recipe for a big flash flood event. For this reason, WPC outlined our region in a level 3/4 and 4/4 risk for flash flooding. The worst of the flash flooding was in Frederick county where 6-8" of rain fell. Elsewhere, a widespread 2-4" of rain fell resulting in scattered flash floods. The Monocacy river in Frederick recorded the highest crest in 25 years, reaching a peak of 25.86 feet (flood stage is just under 18 feet).  

On the evening on November 2nd 2018, a powerful cold front sparked  line of strong thunderstorms that moved across central maryland producing wind damage and 2 confirmed tornadoes, one of which was significant.

The significant tornado occured in Mount airy, and had winds of 120mph. The tornado touched down at 8:20pm and traveled NE for just under 5 miles before lifting south of the Links at Challedon. It first touched down in far NW Hoard county near I-70 before crossing into Carroll county. Significant damage occurred with this tornado including numerous large trees being blown down, as well as major structural damage to a gas station, TJ Max, and 2 local farms. The most severe damage occurred on Rt.27, Watersville rd, and Runkles rd where several large greenhouses were destroyed, and a personal weather station recorded a wind gust of 114mph. The tornado also drained a large pond off Runkles road leaving it dry.

Despite the fairly clear radar indication of a tornado (strong velocity couplet on tilt 2 coinciding with a debris ball on the cc), there was no tornado warning in effect for this storm. Therefore, no one in the area knew it was coming and had no time to prepare. Luckily, there were no casualties as a result of this tornado. This storm is an example of the difficulties related to forecasting high shear low cape severe weather events.

​Forecaster Jack

During the late afternoon on July 12th of 2022, a cluster of severe thunderstorms tracked across northern Maryland producing widespread wind damage. The storm entered Carroll County around 4:05pm and a severe thunderstorm warning was already in effect. Radar out of BWI Airport showed radar beam level wind of 85+mph, with damage surveys showing winds of 75-100mph in some places of Carroll county. Damage consisted of dozens and dozens of downed trees and branches, as well as a portion of the roof from the CCPS BOE being blown off. The hardest hit part of Carroll county was near and north of Westminster as well as Hampstead and Manchester.

As the storm progressed eastward into Baltimore and eventually Harford county, winds continued to gust in the 70-90mph range and produced widespread tree and powerline damage. Per the NWS, "Numerous trees snapped and uprooted in Monkton, Sparks, and Hereford areas" which correlates with where the strongest winds were on radar. Again, radar showed winds of 70-80mph across these areas. The video below was shot in central Baltimore County from Ryan Kane, a meteorologist, where winds are estimated at 65-70mph.

WARNING: Colorful language in the beginning

A third area of concentrated wind damage occured in College park northeast into Greenbelt, where a microburst produced winds to around 90mph. A clear surge in the line of storms resulted in the development of a microburst on the leading edge of the bow echo in this area. According to NWS, dozens of large trees were snapped and sheared off, and at least 1 structure sustained damage. This segment of the storm continued east into AA county with sporadic instances of wind damage due to gusts in the 55-70 mph range. 

On July 30th, 2016, a catastrophic flash flood struck Ellicott city. I lived less than 4 miles south of this at the time, and still get goosebumps when I talk about it. Torrential downpours associated with strong thunderstorms developed over much of Howard county from 5:30 until 9pm dropping many inches of rain over Ellicott City. Due to light, unidirectional winds aloft, the thunderstorms were slow moving, which resulted in rapid flash flooding due to the extreme and persistent rainfall rates over the area. Below is a radar loop from that time frame. The most intense rainfall in Ellicott City occured from about 6:30pm until 8:30pm.

In total, the central part of the county received between 2 and 4" of rain in just 3 hours. But a bullseye over ellicott city indicated 7-12" of rain had fallen. This resulted in a rapid rise of the Patapsco river that flooded the downtown area. The National Weather Service issued an extremely rare flash flood emergency urging people to evacuate or get to higher ground as numerous water rescues were already ongoing. Numerous buildings were flooded, cars washed away, and lives were changed forever. People on Main street were trapped in upper floors of their buildings, only able to watch everything being washed away. The force of the water was so intense that trees and debris were found INSIDE buildings after the flood waters receded.

Rainfall accumulation was as follows in Ellicott City:
1 min- 0.2"
5 min- 0.8:
10 min- 1.44"
15 min- 2.04"
20 min- 2.44"
30 min- 3.20"
60 min- 4.56"
90 min- 5.48"
120 min- 5.96
Data obtained from the ELYM2 rain Gauge
in Ellicott City from NWS

Forecaster Jack

Image/GIF 1 credit: NWS Sterling
​Image 2 credit: NWS Sterling

On March 2nd 2018, a historic severe wind storm impacted the region with widespread damaging to destructive non-thunderstorm winds. A powerful coastal low deepened to 976mb off the east coast resulting in a very tight pressure gradient across the region. Combined with wind speeds of 70-80mph at 850mb (5k feet), the stage was set for a prolonged and high impact wind storm, one that would become one of the worst in recent history.

The national weather service had been messaging the increasing likelihood of a significant wind event for days, giving plenty of time for people to prepare. They issued a high wind warning the day before, and on the morning of, a strongly worded statement mentioning potential for wind gusts over hurricane force. 

The image below was issued the day before, urging residents to prepare for a dangerous wind storm that would result in significant damage across the region. 

Widespread damage occurred, and frankly it was worse than some of the hurricanes we have had around here. Thousands of trees were blown down along with several hundred thousand power outages. At my house, 2 massive pine trees were blown down, shingles were blown off, and numerous large pieces of siding were torn off my house and many of the neighbors as well. I dont think a single house in my neighborhood went without damage. One of my neighbors lost all the siding off the south side of their house. Nearly every weather station in the region recorded winds at or above 60mph, with several near or over 70mph. The long duration of the event was also significant as some areas received gusts over 60mph for 8-12 hours which is practically unheard of in our area.

Photo 1 Credit: NWS Sterling/WPC
Photo 2 credit: NWS Sterling
Photo 3 credit: NWS Sterling

I think that I can speak for all of us when I say we ALL remember this storm...

Everything was in place for a major winter storm to dump feet of snow throughout the region. The storm track was perfect, there was ample cold air, and plenty of moisture, in addition to a well organized and intensifying storm system. A powerful, nearly stationary bomb cyclone sat off the Mid Atlantic coast from the 22nd until the 23rd of January dropping 2-3 feet of snow in our region. This storm may have undergone a process known as "Repeated Cyclogenesis", which is when the center of the low pressure collapses and reforms over and over again. Not only this, but wind gusts reached 50mph in some areas resulting in blizzard conditions, and for this reason, a blizzard warning was in effect. 

It was quite remarkable how consistent and accurate the weather models were in depicting this storm. They started showing a heavy snowstorm about a week in advance. And this time, they were right. Snowfall rates during this storm were in the 2-3" per hour range which is very heavy. Additionally, convective elements developed which resulted in lightning strikes across the Baltimore region. Several days in advance, we posted a forecast calling for 24-30" across the area, and that forecast verified very nicely. At my house in Ellicott City, 30" of snow fell. At BWI, there was just over 29", and the same goes for Dulles. Some areas in northern and western MD saw over 3 FEET of snow. This was one of the largest snowfalls on record for the region. The highest snowfall report came in from Glengary WV, where 42" was recorded. 

Forecaster Jack

Photo 2 credit: NWS Sterling

What is a derecho? Many people across or region had never heard the term before. That was up until June 29th, 2012. A derecho is a powerful line of severe thunderstorms that produces widespread and significant wind damage. To meet the criteria of a derecho, this line of storms must travel at least 240 miles, and produce widespread wind gusts of 60mph, and at least widely scattered wind gusts over 75mph. That's exactly what happened that night. 

The cluster of storms first developed near Chicago, and then raced ESE across the midwest and into the mid atlantic. The atmosphere was incredibly unstable with record high temps. As the storms reached the mountains, they weakened slightly. But as soon as they hit the extremely unstable air to the east of the mountains they rapidly intensified as it plowed across the state. The lead time on this derecho (like most derechos) was not very good. This likely caught many people off guard, and may have been the reason behind some of the fatalities that resulted from this storm. That said, NWS did a very good job at issuing timely severe thunderstorm warnings as the storms approached. In fact, every county in the NWS Sterling forecast area was under a severe thunderstorm warning at some point.

The amount of wind damage that this derecho produced was historic. Wind gusts of 70-90mph were measured all across the path with widespread trees and powerline damage. During the peak, over a quarter million people in maryland alone lost power. Locally, winds gusted to 71mph at Dulles, 70mph at Regan National, and 66mph at BWI. Several weather stations across central/southern MD recorded wind gusts of 75-85mph. Hundreds if not thousands of trees were blown down.

Forecaster Jack

Image 1 credit: NWS Sterling
Image 2 credit: Storm Prediction Center

The National Weather Service, after surveying damage, determined that a very brief EF-0 tornado touched down around 9:01PM in the vicinity of Colton’s Point, Maryland on Monday, June 10th, 2013. Minor damage relating to trees and roof shingles was noted near the intersection of Maryland Route 242 (Colton Point Road) and Bayview Road, as well as along portions of Beach Road between Charles Hall Road and Point Breeze Road. In this area, a tree was toppled onto some utility wires, and a trampoline was blown ninety feet up and lodged in a pine tree. Additionally, two large wooden play sets were blown over, with one being dragged nearly fifteen feet. After its brief stint, the tornado only traveled about a quarter of a mile, with a maximum path width of only fifty yards. Maximum wind speeds within the tornado were estimated to only be about 65 MPH, with no injuries or fatalities reported.

​...Forecaster Zach...

Around 8:32PM on Friday, May 27th, 2022, a tornado touched down near the junction of Maryland Route 5 (Leonardtown Road) and Maryland Route 231 (Prince Frederick Road), along the border of Saint Mary’s and Charles County, in Charlotte Hall, Maryland. In this area, a few trees were damaged along Bach Drive and Maryland Route 5 (Leonardtown Road). A couple dozen trees were snapped and uprooted in the area of Mount Wolf Road and White Drive, where a few downed tree branches lead to siding and window damage on a housing structure. Around this time, the tornado peaked in strength, as an EF-1 system, estimated to have maximum wind gusts around 90 MPH. Some tree damage then continued as the tornado trekked northeastward into the area of Chappelear Drive and Mount Wolf Road. In this area, another uprooted tree fell onto house, but lead to no injuries. Sporadic tree damage was also noted along Maryland Route 231 (Prince Frederick Road), between Barney Drive and Colonial Drive. The tornado traveled a total of four and an eighth miles, before lifting off of the ground at 8:41PM, near benedict, Maryland, with a maximum path width of one hundred yards. No injuries or fatalities were reported.

​...Forecaster Zach...

Around 12:22PM on Friday, May 27th, 2022, a tornado first touched down around the 3600 block of Toddsbury Lane in Olney, Maryland. Around this area, numerous tree limbs were downed, leading to some vehicular damage. The tornado then temporarily lifted off of the ground for a short time before touching back down once again and uprooting a number of trees near the cul-de-sac of Toddsbury Lane. Some of the fallen trees in this area had a trunk diameter of over two feet wide, with some of them blocking a pathway between the cul-de-sac and Queen Elizabeth Drive, and even damaging a few more automobiles in the area. In this area, people reported that there was a visible debris field near the cul-de-sac. After its brief, one minute stint, the tornado had only traveled a quarter of a mile and lifted off of the ground at 12:23PM. Maximum wind gusts within the tornado were estimated to be around 80 MPH, with its maximum width being only 125 yards. No injuries or fatalities were reported as a result of the EF-0 tornado

​...Forecaster Zach...

Around 7:28AM on Friday, February 7th, 2020, a short-lived one minute long EF-1 tornado touched down in Dickerson, Maryland, just to the west of a local farm located along the Potomac River near Martinsburg Road. At the farm, a few trees were downed and the roof was torn off of an older barn located on the property. Additionally, a few smaller buildings on the farm were toppled, as well as the metal frame of a windmill. The tornado then crossed Martinsburg Road, where a number of trees were snapped or uprooted, before lifting off of the ground at 7:29AM. The survey completed by the National Weather Service estimated that the tornado traveled one mile with peak wind gusts topping off around 95 MPH, and a maximum width of one hundred fifty yards. No injuries or fatalities were reported as a result of the tornado.

​...Forecaster Zach...