11:45 AM (Friday) | **Unseasonably warm weather today ahead of strong cold front…progressively colder this weekend…snow a threat in parts of the Mid-Atlantic late Sunday night/early Monday morning**
Paul Dorian
Snow (shown in blue) is possible early next week in parts of the Mid-Atlantic region as low pressure intensifies near the Mid-Atlantic coastline; map courtesy NOAA, tropicaltidbits.com
Overview
Unseasonably warm weather dominates the scene today in much of the Mid-Atlantic region with temperatures at mid-day ranging from the 70’s in DC to the 60’s in Philly while stubborn cool air is hanging on in NYC with temperatures in the 50’s. A strong cold front is closing in on the eastern states at this hour and will produce afternoon and evening showers and perhaps a strong-to-severe thunderstorm or two. Following the passage of the strong cold front later tonight, the weekend will become progressively colder as strong high pressure builds into southeastern Canada. By the end of the weekend, moisture will be advancing northeastward towards the Mid-Atlantic region and our entrenched cold air mass will be reluctant to give up its ground as high pressure slides toward the Canadian Maritimes. As a result, there is the chance for some snow or a mix of rain and snow in at least parts of the DC-to-Philly-to-NYC corridor from later Sunday night into early Monday with significant snow possible across interior, higher elevations of the Mid-Atlantic and NE US.
Strong, cold high pressure will be situated over southeastern Canada during the latter part of the weekend anchoring a cold air mass in the Mid-Atlantic and NE US; courtesy NOAA, tropicaltidbits.com
Details
Temperatures at mid-day have climbed into the 70’s in the DC metro region and into the 60’s in Philly and surrounding suburbs. The record highs in the DC metro region of 77 degrees at Dulles Airport and 83 degrees at DCA are in some jeopardy later today, but it won’t be an easy task. Meanwhile, stubborn cool air is hanging on in the NYC metro region with temperatures confined to the lower 50’s at mid-day with low clouds and fog in place. In addition to the warmth, the winds will pick up noticeably this afternoon from a southwesterly direction and there are going to be occasional showers this afternoon and evening and perhaps a late day strong-to-severe thunderstorm – some of the rain will be heavy at times.
A wave of energy in the upper atmosphere will aid in the intensification of low pressure near the Mid-Atlantic coastline on Monday; courtesy NOAA, tropicaltidbits.com
Following the strong cold frontal passage, the weekend will turn progressively colder in the Mid-Atlantic region with highs on Sunday afternoon confined to the 40’s as compared with the 70’s on Friday. By late Sunday, strong, cold high pressure will be situated over the southeastern part of Canada anchoring our cold air mass and it will be slow to retreat to the northeast on Sunday night and Monday. At the same time, moisture will be advancing this way from the Tennessee Valley and it may still be cold enough for some snow or a mix of rain and snow late Sunday night and early Monday in at least parts of the Mid-Atlantic region before a likely changeover to plain rain. As is the normally the case this time of year, the favored areas for snow will be the higher elevation locations to the north and west of Route I-95. Stay tuned.
Meteorologist Paul Dorian
Perspecta, Inc.
perspectaweather.com
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