Snow likely Wednesday night/Thursday morning
POSTED ON: Wednesday, February 10, 2021 11:44 AM by METEOROLOGIST A.R. DAVIES
Multiple “waves” of energy/precipitation will track along a stalled cold front to our south through the end of the work week. The first wave of energy will pass tonight through midday on Thursday. Precipitation will likely arrive in Annapolis around 1900 tonight as light snow or sleet. As is often the case, the transition line for precipitation types will likely hover near Annapolis overnight (likely wobbling between BWI Airport and Patuxent River NAS), before eventually transitioning to all snow at some point Thursday morning. That is not to say that all snow will not fall periodically in the evening or overnight because it will likely occur during steadier periods of precipitation. But the precipitation type could go back and forth between snow, sleet, and perhaps rain overnight with surface temperatures hovering between 31oF and 34oF in Annapolis.
The forecast for Annapolis is 2.0 to 5.0 inches of snow/sleet tonight through midday on Thursday. Uncertainty remains high in the orange dashed region, particularly on the lower end as the precipitation type transition line will likely move north/south throughout the event. There is a 25% chance that Annapolis will get more rain and/or sleet which would reduce accumulations below 2.0 inches, and only a 10% chance that the event is all snow and that the rates are steady/heavy resulting in more than 5.0 inches. Snowfall totals between BWI Airport and Southern PA will likely range 2.0 to 4.0 inches widespread, with isolated locations totaling 4.0 to 6.0 inches of snow. See map below for details. The National Weather Service Baltimore/Washington has issued a Winter Weather Advisory for Anne Arundel County from 1900 on Wednesday through 1000 on Thursday.
There will likely be a lull in precipitation on Thursday afternoon with the next wave expected to pass Thursday evening and continue until into Friday morning. Once again, the location of the stalled arctic front will be important for the location of the heaviest snowfall. Right now, it looks like the front will push far enough south for the heaviest snowfall to be south of Annapolis (and perhaps even south of Maryland). The current forecast is for less than 1.0 inch of snow in Annapolis, but this remains uncertain. There is a 25% chance of no snow in Annapolis if the precipitation is too far south and a 25% chance of > 1.0 inch of snow if the precipitation sets-up further north. Surface air temperatures on Thursday, Thursday night, and Friday are expected to be near or below 32oF in the Annapolis area. See map below for details on anticipated snow 1200 on Thursday through 1200 on Friday. If the forecast changes and more than 1.0 inch of snow is expected, an additional update will be distributed to the weather email list on Thursday.
Looking ahead, the pattern will likely remain active through next week with two or three more opportunities for wintry weather. The net system will likely be a weakly developed coast Low that will pass just offshore Saturday afternoon through Sunday morning. Initial indications are that the surface layers of the atmosphere will be near or below 32oF, however temperatures aloft may not uniformly be below freezing. Therefore, this has the potential to be an impactful wintry mix event with snow, sleet, and/or freezing rain possible. More details to follow in the coming days.
ISSUED: 10 February 2021 at 1140
FORECASTER: Meteorologist A.R. Davies
Category: General Interest, Press Releases