As Baltimore braces for light wintry precipitation today, the National Weather Service Baltimore MD/Washington DC has issued an Area Forecast Discussion noting the passage of low pressure to the south. High pressure is expected to make a brief return over the weekend, but not before a strong cold front tracks across the region on Sunday evening.
The forecast for today includes the possibility of light snow, especially to the south near the I-64 corridor, where 2 to 3 inches may fall, while areas northward to U.S. 50/I-66 could see 1 to 2 inches; however, the dry air has been limiting accumulation so some Winter Weather Advisories might be canceled early, the snowfall gradient has shown a sharp north-south orientation with I-66 serving as a loose boundary for the event and for those north of I-66 it remains to be seen if more than a coating of snow will be observed as the day's coldest temperatures won't escape the low/mid 30s. Clouds will dominate, but some late-day clearing could occur near the Shenandoah Valley.
Into the night, low stratus clouds and the potential for patchy freezing fog create the need for caution due to possible icy conditions on untreated surfaces. According to the National Weather Service forecast, for those out and about tonight, exercise some caution as fog droplets freeze on contact with untreated surfaces. Overnight lows are predicted to fall into the upper teens to 20s, and light winds accompany as weak high pressure builds in.
The weekend is shaping up to be tranquil with a progressive long wave pattern and highs in the low/mid 40s, about 5 to 10 degrees below early December averages; clouds and sun will mix throughout the weekend, cloud cover will increase on Sunday ahead of the next system and some precipitation chances are expected by Sunday afternoon/evening, especially across the Allegheny Front, with up to an inch of snow posisble, maybe more if the precipitation stays as snow a series of clipper lows will track north of the region through midweek bringing with them varying temperatures and mostly dry conditions until Thursday.
For aviation and marine, both sectors face restrictions and advisories owing to the current weather conditions; VFR conditions return over the weekend, but gusty northwesterly winds will pick up Sunday night after the cold front, while Small Craft Advisories remain in effect until early Friday morning for the Chesapeake Bay and other waterways, anticipating SCA-level winds again by Monday in north-northwesterly flow. All terminals should expect some light snow, but conditions should improve moving into next week.
