Sunday 9:50 AM | **It ain’t over till it’s over…accumulating snow late tonight/early Monday...second threat continues for next weekend**
Paul Dorian
06Z NAM forecast map for early Monday morning with widespread snow (in blue) north of the PA/MD border; map courtesy NOAA/EMC, tropicaltidbits.com
Overview
This is no April Fool’s joke…accumulating snow is coming to much of the I-95 corridor late tonight and early Monday. There have been two threats to monitor for this upcoming week in terms of the potential for snow and the first one is indeed going to result in accumulating snow and the second threat is still definitely on the table for next weekend.
Discussion
A cold front will work its way through the region today and then low pressure will ride along the frontal boundary zone on Monday towards the Mid-Atlantic coastline. Rain is likely to break out around or shortly after midnight in the DC-to-Philly-to-NYC corridor and quickly chance to a wintry mix north of the PA/MD border and then to all snow later in the night. The snow will continue tomorrow morning in those areas north of the PA/MD border - perhaps heavily at times - and then will wind down by mid-day possibly mixing with or changing back to rain before ending.
In areas south of the PA/MD border, the changeover of the rain to a wintry mix and then possibly to snow will be slower compared to north of the Mason-Dixon Line. All areas along the I-95 corridor should see some clearing skies tomorrow afternoon and rapidly improving road conditions.
In term of snow accumulations…2-4 inches is likely in the Philly and NYC metro regions with isolated higher amounts possible. Slippery spots are possible for the morning commute in both of these metro regions during any heavy snow band activity.
In the DC metro region, a coating to an inch or two is possible across the far northern and western suburbs; primarily, on grassy surfaces and little or no accumulation is expected in and around DC.
06Z GEFS forecast map of 850 temperature anomalies averaged over a 5-day period from days 6-10 (April 6-April 11); map courtesy NOAA/EMC, tropicaltidbits.com
Looking ahead, showers are likely in the I-95 corridor on Tuesday with the approach of a warm front and then rain is likely on Wednesday with the arrival of a strong cold front. That strong cold front will set the stage for a very cold period for this time of year from this mid-week into at least the middle of next week. This Thursday is Opening Day for the Phillies in South Philly and the Nationals in Wash., DC and it will be windy and abnormally cold in both places with wind chills likely in the 30’s.
Another threat of snow is still on the table for next weekend as low pressure could very well arrive with unusually cold air in place in the Mid-Atlantic region…stay tuned, it could be a big one.
Meteorologist Paul Dorian
Vencore, Inc.
vencoreweather.com