****Showers and possible severe thunderstorms in the Mid-Atlantic region on Friday and Friday night…holiday weekend starts off unsettled, but should end well though it’ll get very warm****
Paul Dorian
Bands of strong-to-severe storms will form on Friday in the Mid-Atlantic region and continue into Friday night as depicted here for two different times by a high-resolution forecast model known as the HRRR. Maps courtesy NOAA, tropicaltidbits.com
Overview
The combination of an increasingly humid air mass, strong surface frontal system and a vigorous mid-level low will help generate numerous showers on Friday and Friday night in the Mid-Atlantic region and possible severe thunderstorms. In fact, there may be two bands of thunderstorms to closely monitor during this event- one during the mid-day/early afternoon hours and a second during the late evening associated with the frontal passage. The main severe weather parameter threats will be damaging wind gusts, “flash-flooding” downpours, and isolated tornadoes are even possible. The upper-level low will be rather slow-moving from west-to-east and this is likely to result in an unsettled weather day on Saturday in the Mid-Atlantic region with scattered showers and strong thunderstorms. The upper-level will exit off the coast on Sunday resulting in improvement to end the weekend and the weather on Monday, Memorial Day, should feature plenty of sunshine, very warm conditions and highs well up in the 80’s.
An upper-level low will play a key role in the severe weather threat on Friday and Friday night in the Mid-Atlantic region as it slowly moves from west-to-east across the area. Map courtesy NOAA, tropicaltidbits.com
Details
The weather becomes very active on Friday in the Mid-Atlantic region with the approach of a cold frontal system. The surface cold front will be supported by a vigorous wave of energy aloft and the result is likely to be numerous showers from Friday into Friday night along with the possibility of severe thunderstorms. In addition to the surface front and upper-level system, another ingredient adding instability to the atmosphere will be higher humidity levels as broad southerly will advect air into the region from the Gulf of Mexico. Dew point temperatures - which are a true measure of moisture levels in the atmosphere - will climb as high as the upper 60’s/lower 70’s in a good part of the Mid-Atlantic region. Bands of strong-to-severe storms are likely to form early on Friday and the threat will continue all the way into the evening. In fact, there may be two bands of thunderstorms to closely monitor during this event- one during the mid-day/early afternoon hours and a second during the late evening associated with the frontal passage. The main weather parameters of concern will be damaging wind gusts and “flash flooding” downpours - given the expected high humidity levels - and isolated tornadoes are certainly on the table.
The holiday weekend looks like it will start off unsettled as the slow-moving mid-level low will push overhead early Saturday leading to lingering instability in the atmosphere and the possibility of showers and even strong thunderstorms. The best chance for the rainfall on Saturday is likely to be during the mid-day and afternoon hours after some daytime heating destabilizes the atmosphere. The day should certainly not be a washout with much of the time rain-free.
Memorial Day will likely turn out to be a hot holiday in much of the eastern third of the nation including in the Mid-Atlantic region as very strong high pressure ridging will develop in the upper part of the atmosphere. Map courtesy NOAA, tropicaltidbits.com
This upper-level system will weaken somewhat by Sunday and continue to edge to the east and overall conditions will improve for the second half of the weekend. With more sunshine expected on Sunday as compared with Saturday, temperatures should climb and then it’ll become very warm on Monday, Memorial Day, as strong upper-level ridging takes control in the eastern US. With this system in place aloft, it’ll stay very warm on Tuesday as well in much of the eastern third of the nation. Both Monday and Tuesday afternoon could feature high temperatures near the 90 degree mark in much of the DC-to-Philly-to-NYC corridor.
Meteorologist Paul Dorian
Arcfield
arcfieldweather.com
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