January 9th high impact noreaster with tropical storm conditions, school closures, and widespread flooding

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.