recap of impactful weather events of 2023

APRIL 1ST SEVERE WEATHER AND POST FRONTAL DAMAGING WINDS.

On April 1st, a very strong cold front intersected an unusually unstable airmass across northern and central MD during the evening. This resulted in rapidly developing severe thunderstorms that produced large hail and damaging winds. Severe thunderstorm warnings were issued across northern and northcentral MD as repots of hail up to quarter size and winds over 50mph became common. ​

Below is a radar screenshot of the storms at about 6:05pm: 

Immediately after the storms passed, a surge of cold and dry air rushed in resulting in very high pressure gradient winds across the area. NWS had already issued a high wind warning in advance of these winds which is fairly uncommon as confidence was high in winds gusting to at least 60mph. 

Widespread wind gusts of 50-60mph occurred with some gusts even over 65mph in a few isolated areas. This resulted in numerous trees and powerlines being blown down and many power outages. Some of the highest wind gusts were 52mph in Mount Airy, 68mph in Woodsboro, 63mph at BWI, 65mph in Cabin John, and 62mph in Upper Marlboro. 

Below is a screenshot from the NWS Sterling site of recorded wind gusts that day:

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april 22nd severe weather event (2 tornadoes)

During the mid afternoon on April 22nd, a line of severe storms tracked through our area as a cold front moved in. These storms produced numerous instances of wind damage especially in the Baltimore metro, as well as 2 confirmed tornadoes. One was in Poolesville, and the other was in Fallston. 

​Below is a radar screenshot of the line of storms moving through MD at about 2:30pm:

Two tornadoes also occurred as a result of this squall line. 

The first was in southwestern Montgomery county near Poolesville. This tornado developed in the bookend vortex portion of the line of storms. It was rated EF0 with winds of around 75mph. The tornado was on the ground for about 1 minute and traveled only 100 yards resulting in primarily tree damage. 

A second tornado was confirmed to have touched down in Fallston up in Harford county (although the tornado actually first touched down in extreme eastern Baltimore county) along the leading edge of the line of storms. This tornado was rated EF0 as well, also containing winds of 75mph. However this one traveled much further, at just under 7 miles. Damage consisted again of mainly trees but some powerlines and structures did sustain damage as well. 

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early june canadian wildfire smoke

Over the summer, several bouts of wildfire smoke from Canada was brought into our area due to winds aloft from the NW. The worst of it by far was in early June. During this time, visibility was reduced significantly in some areas, and code red air quality alerts were issued for the first time since 2011.

Much of our area saw AQI (air quality index) values climb into the 250-400 ppm range, which is extremely unhealthy and hazardous. For reference, it's considered unhealthy for sensitive groups when the AQI exceeds 50-100 ppm, so our values were off the charts. In fact the smoke was so thick that without a mask, it was difficult to breath and you would feel a burning sensation in your eyes and throat.

You can see in the image below of satellite captured on June 6th just how widespread the smoke was all across the east coast. Luckily by the end of June and into July, winds shifted more southerly and rain became more frequent, clearing the air of the dense smoke.

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late july severe winds due to microbursts (mount airy and dc metro)

The last week of July featured atmospheric conditions favorable for the development of microbursts. Very hot and humid conditions along with dry air aloft and approaching cold front set the stage for very strong downburst winds in scattered severe thunderstorms. This happened on several occasions over the summer, but 2 days in particular had very notable ones.

The first one occurred in Mount Airy on the 28th. A small storm cell rapidly intensified and grew in size as it tracked through western Montgomery county and into southern Carroll county where it produced extensive tree and powerline damage from Mount Airy into Winfield. After surveying the damage, I estimated that winds reached 70-75mph in much of the damaged areas, with a few spots seeing peak winds around 90mph.

The image below is the approximate location of the microburst that impacted Mount Airy along with damage reports.

On July 29th, another series of microbursts impacted the DC metro, including Montgomery, PG and Anne Arundel counties with recorded wind gusts as high as 84mph in DC. A line of severe thunderstorms developed first near Dulles Airport, before moving rapidly east into the immediate DC metro and eventually into south central Maryland. 

These storms resulted in widespread 50-60mph winds, but several microbursts embedded within the line of storms produced wind gusts of 75-90mph, equivalent to a category 1 hurricane. These winds resulted in significant and widespread wind damage across the metro area and into PG/AA counties as well. 

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august 7th severe weather outbreak

We first mentioned the possibility of severe weather for August seventh all the way back on August 3rd. Confidence grew substantially on the 5th as it became clear we were in for a major severe weather outbreak in just 48 hours. On August 7th, SPC upgraded our area to an extremely rare MODERATE RISK (level 4/5) for severe weather. This was the first time they have done that in over a decade (last time was June 13th 2013), and so we sent out a very strongly worded message that this was going to be a very rough afternoon and evening. 

The worst of the weather was focused across northern MD where a bow echo produced wind gusts of 70-90mph and widespread major wind damage. Hundreds of trees were blown down and dozens of powerlines were snapped in downtown Westminster trapping cars underneath for hours. A rare destructive tagged severe thunderstorm warning was issued for part of this bow echo as well, urging people to treat this like a tornado warning due to the extreme nature of the wind. 

Additionally, hail as large as tennis balls fell in Washington county, and 2 tornadoes were confirmed in our viewing area. The first was in extreme northern Carroll county and traveled into southern York county, and the second was in eastern York county. These tornadoes occurred as the supercell from Washington county merged with the bow echo resulted in an enhanced area of spin within the line of storms. 

December 18th nor easter 

On December 18th, a very strong area of low pressure tracked up the east coast bringing rain and wind to our area. The area of low pressure strengthened to 983mb, which while not as intense as what models showed, was still very strong and brought significant rain and wind impacts to our region. 

Rain developed on the 17th and became very heavy overnight as the storm system moved north closer to our area. In total, most areas saw between 2 and 3 inches of rain with some localized amounts up to 5" observed as well. This did result in numerous flood warnings overnight with several instances of flooding as well. 

The image below shows some of the reported rainfall totals across our area from NWS Sterling. 

There was also a strong wind component to this storm. As it pulled away and intensified, its pressure gradient tightened over our area. This allowed strong winds to develop and a wind advisory was issued. Many areas saw winds gusting as high as 50mph, with locally higher gusts as well in a few spots.

Some of the highest recorded gusts were 59mph in Sabillasville, 55mph in Cabin John, 51mph in Clarksville, and 47mph at BWI Airport. Because of how wet the ground was, it was much easier for trees to fall and several thousand customers were without power during this wind event. Strong winds of 40-45mph also continued into Tuesday the 19th as the area of low pressure was still over New England with a tight pressure gradient overhead. 

The image below shows some of the peak wind gusts across our area from NWS Sterling.

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Of course there were other smaller events this year that were impactful, but these are the ones we feel had the highest and/or most widespread impacts to our region.