7:00 AM | Strong cold front reaches the coast tonight; heavy rainfall and strong storms can be expected; nor’easter forms along the front and affects the early weekend weather

6-Day Forecast

Today

Mostly cloudy, still warm and humid, but not quite as warm as yesterday, occasional showers and possible afternoon thunderstorms, any shower can be heavy and some of the PM thunderstorms can be strong-to-severe with heavy rainfall, strong wind gusts and hail, highs in the upper 70’s

Tonight

Mostly cloudy, mild early, turning cooler late, occasional rain and a couple of thunderstorms possible, some of the rain can be heavy at times and any storm can be strong-to-severe with heavy rain, strong gusty winds and hail, lows in the upper 50’s by morning

Friday

Mostly cloudy, windy, much cooler, lingering showers likely, low 60’s

Friday Night

Mostly cloudy, windy, chilly, showers likely, mid 40’s

Saturday

Lots of clouds, windy, cool, lingering showers likely, low 60’s

Sunday

Becoming partly sunny, breezy, cool, mid-to-upper 60’s

Monday

Mostly sunny, cool, near 70

Tuesday

Partly sunny, milder, low-to-mid 70's

Discussion

Big changes are on the way for the Mid-Atlantic region over the next couple of days as the pattern transitions from summer-like to rather winter-like by early this weekend with a full-fledged nor'easter developing off the Northeast US coastline. The transition from summer's warmth and humdity to yet another chilly air mass has actually already begun as the peak in the heat occurred yesterday with highs in the upper 80's in many parts of the region. Temperatures will actually drop more than 40 degrees over the next couple of days from yesterday's highs in the upper 80's to weekend lows in the middle 40's. As a powerhouse cold frontal system approaches the east coast today, there will be occasional showers and thunderstorms. Any shower can contain heavy rainfall and any thunderstorm that forms this afternoon and evening can reach strong-to-severe levels with heavy rain, strong gusty winds and hail. In fact, there will likely be scattered strong-to-severe thunderstorms up and down the east coast later today from the Carolinas to New England as this strong cold front heads to the coast.

Once the cold front reaches the east coast later tonight, a strong upper level low will dig into the Mid-Atlantic region, and this will to cause the frontal system to grind to a halt as a nor’easter-type of coastal storm develops at the same time much chillier air pours into the region. As a result, Friday will turn out to be breezy and much cooler than today in the Mid-Atlantic region with lots of clouds and residual showers and, as the coastal storm only slowly pulls away to the northeast, Saturday will likely also turn out to be quite cloudy, windy and cool with the continued threat for showers. The colder air mass will actually allow for the possibility for snowflakes to fall in some of the interior, higher elevation (>2000 feet) locations of the Mid-Atlantic and Northeast US early this weekend (e.g., Adirondacks, Green and White mountains). By Sunday, strong Canadian high pressure should finally take control of the weather and there will be some clearing and then Monday looks like the best day of the three this weekend with plenty of sunshine expected. Temperatures will stay below normal, however, on Sunday and Monday (normal high is now 75 degrees).

7:00 AM | Another summerlike day with heat and humidity; strong storms possible today and Thursday; much cooler this weekend

6-Day Forecast

Today

Clouds this morning, partial sunshine this afternoon, very warm and humid, chance for showers and thunderstorms this afternoon and any storm that develops can be strong, highs in the mid 80’s

Tonight

Mostly cloudy, mild, chance for showers and thunderstorms and any storm that forms can be strong, low-to-mid 60’s

Thursday

Mostly cloudy, warm and humid, showers and thunderstorms likely and some of the storms can be strong-to-severe, near 80

Thursday Night

Mostly cloudy, mild early, turning cooler late, chance for showers and thunderstorms, mid-to-upper 50’s by morning

Friday

Mostly cloudy, breezy, cooler, chance for residual showers, upper 60's

Saturday

Slow clearing, windy, cool, still cannot rule out a couple of showers, low-to-mid 60's

Sunday

Mostly sunny, breezy, cool, mid-to-upper 60's

Monday

Partly sunny, still on the cool side, near 70

Discussion

A taste of summer will continue today in the Mid-Atlantic region as temperatures will climb well up into the 80’s in most locations and humidity levels will stay on the high side. Dew points climbed into the middle 60’s on Monday in the Mid-Atlantic region and then they reached the even more stifling upper 60’s on Tuesday to go along with summerlike temperatures. Showers and thunderstorms can break out at just about any time this afternoon and evening although much of the time will be rain-free. Any storm that forms this afternoon or evening can be on the strong side with some briefly heavy rainfall and perhaps hail and high wind gusts. By tomorrow, a strong cold front will be moving through the Ohio Valley on its way to the east coast and this will enhance the chances for shower and thunderstorm activity in the Philly metro region and there is a decent chance that strong-to-severe storms will develop later tomorrow and tomorrow night in the entire region between the Carolinas and New England.

Once the cold front reaches the east coast by early Friday, it will tend to slow down a bit as a coastal storm develops and this will allow for mostly cloudy skies to continue on Friday along with cooler conditions and the threat for residual showers and this may even linger into Saturday as well. By later in the weekend, strong Canadian high pressure will build into the Mid-Atlantic region and, similar to many previous springtime scenarios, much colder-than-normal air will spread to the eastern states with this high pressure system. As a result, it does not look at all like a “beach-type” weekend for coastal locations in the Mid-Atlantic and Northeast, and frost is actually not out of the question for some interior, higher elevation locations. Cool and dry weather is likely to continue into the latter part of the Memorial Day weekend.

One final note: the tornado that struck Oklahoma on Monday has now been upgraded to an "EF-5" classification level which is the most intense type on the "Enhanced Fugita" scale and it is suggestive of 200+ mph winds.

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