Snow Likely Thursday Morning; Transitioning to a Mix by Midday
POSTED ON: Tuesday, February 16, 2021 9:44 AM by METEOROLOGIST A.R. DAVIES
A broad area of Low pressure will likely pass just to our south and near the mouth of the Chesapeake Bay on Thursday. The system will be enhanced by energy in the mid-levels of the atmosphere and the position of the jet stream aloft.
Precipitation will overspread Central Maryland before sunrise on Thursday morning. Temperatures at the surface and throughout the atmospheric column will initially be below freezing with periods of moderate snow likely through mid-morning. Warm air will wrap into the system overhead from south to north throughout the day. By mid-morning the snow will likely transition to mostly sleet in Annapolis which could significantly cut-down on overall snow/sleet totals. As warm air continues to push northward, a transition to freezing rain and/or rain will likely occur sometime around midday in Annapolis.
2.0 to 5.0 inches of snow/sleet accumulation is likely for the greater I-95/metro region (see blue shaded region on the forecast map). However, at this time I expect Annapolis to be on the lower end of that range due to a quicker transition to sleet compared to our neighbors to the north. Therefore, 2.0 to 3.0 inches of snow/sleet mix is anticipated through midday on Thursday in Annapolis. Thursday afternoon represents the greatest uncertainty with the system as a sleet/snow mix could persist if the system is a little colder (perhaps accumulating an additional inch with low snow ratios), freezing rain could develop if temperatures throughout the atmospheric column are above freezing but remain at or below freezing at surface (with 0.1 to 0.25 inches of ice accretion possible), or a transition to all rain could occur. Either way, plan on some travel impacts during the Thursday morning commute.
The transition between precipitation types will likely occur gradually from south to north during the day on Thursday. Lower totals/impacts are expected south of Annapolis and higher totals/impacts are expected north of Annapolis. Depending on how the system behaves Thursday afternoon/evening, 0.1 to 0.25 inches of ice accretion is possible inside the light blue dashed region on the map, on top of the snow/sleet accumulation. It will likely remain cold enough to support mostly snow further north and west and therefore high totals are expected. See map for details.
ISSUED: 16 February 2021 at 00950
FORECASTER: Meteorologist A.R. Davies
Category: Press Releases, General Interest