7:00 AM | High chance for showers and thunderstorms next couple of days and some of the rain will be heavy; quite a cool weekend on its way

6-Day Forecast

Today

Partly sunny, quite warm, humid, chance for mid-to-late afternoon showers and thunderstorms, highs in the upper 80’s

Tonight

Mainly cloudy, mild, chance for showers and thunderstorms, lows in the upper 60’s

Friday

Partly sunny skies, a tad cooler, chance for showers and thunderstorms, low-to-mid 80’s

Friday Night

Mostly cloudy, mild, good chance for showers and thunderstorms, upper 60’s

Saturday

Mostly cloudy, quite cool, chance for a few showers and possibly a thunderstorm, upper 70’s

Sunday

Partly-to-mostly sunny, quite cool, mid-to-upper 70’s

Monday

Mainly sunny, still quite cool, mid-to-upper 70’s

Tuesday

Mainly sunny, pleasant, near 80

Discussion

An active weather pattern is in store for the Mid-Atlantic region over the next couple of days as waves of low pressure move along a stalled out frontal boundary zone. Scattered showers and thunderstorms are likely to affect the region through tomorrow night and possibly even on Saturday and some of the rain will fall heavily at times. Canadian high pressure will eventually build south into the region from southeastern Canada and this system will end up being the main weather feature by later this weekend and through the early part of next week and it will generate an unusually cool low-level east-to-northeast flow of air into the region. In fact, high temperatures this weekend up and down the I-95 corridor region from DC-to-New York City will generally be confined to the 70's which is well below normal for this time of year.

Video

httpv://youtu.be/igexlIu5pHw

7:00 AM | More unsettled pattern with an increasing threat for showers and thunderstorms

6-Day Forecast

Today

Partly sunny, warm, more humid, chance for showers and thunderstorms late, highs in the mid-to-upper 80’s

Tonight

Mainly cloudy, mild, chance for showers and thunderstorms, lows in the upper 60’s

Thursday

Mostly cloudy skies, warm, humid, chance for showers and thunderstorms, mid-to-upper 80’s

Thursday Night

Mostly cloudy, mild, chance for showers and thunderstorms, upper 60’s

Friday

Partly sunny, cooler, chance for showers and thunderstorms, low 80's

Saturday

Mostly cloudy, downright cool, chance for showers, upper 70’s

Sunday

Mainly sunny, still cool, upper 70's

Monday

Partly sunny, pleasant, chance for showers, near 80

Discussion

This morning's air mass is noticeably more humid than recent days and with the rise in humidity will be an increased chance for showers and thunderstorms by later in the afternoon. A frontal system has stalled in the southern part of the Mid-Atlantic region and a couple of disturbances will ride along the boundary zone during the next couple of days. As a result, the threat for scattered showers and thunderstorms that begins late today will continue right into Friday and there will be a cooling trend as go through the weekend. Temperatures will reach the mid-to-upper 80's today, but will likely be confined to the upper 70's for highs this weekend.

7:00 AM | Stalled out frontal system brings us the chance for showers and thunderstorms from late tomorrow into Friday

6-Day Forecast

Today

Mostly cloudy this morning, partial sun this afternoon, a tad cooler-than-normal, more humid, highs in the mid 80’s (normal high is now 87 degrees at DCA)

Tonight

Partly cloudy, mild, lows in the mid-to-upper 60’s

Wednesday

Partial sunshine, warm, humid, mid 80’s

Wednesday Night

Mostly cloudy, mild, chance for showers and thunderstorms, upper 60’s

Thursday

Mostly cloudy, warm, showers likely with possible thunderstorms, mid 80’s

Friday

Mostly cloudy, cooler, still the chance for showers, near 80

Saturday

Partly sunny, still on the cool side, chance for showers, near 80

Sunday

Partly sunny, still cooler-than-normal, near 80

Discussion

A frontal system has stalled in the southern part of the Mid-Atlantic region and a few disturbances will ride along the boundary zone during the rest of the week. As a result, the threat increases later tomorrow and tomorrow night for scattered showers and thunderstorms and this threat will continue on Thursday and Friday as well. Temperatures will generally stay at normal or slightly below normal levels through the week.

Video

httpv://youtu.be/z-RqlBjeo1w

7:00 AM | A front stalls nearby and this leads to an unsettled week

6-Day Forecast

Today

Mostly cloudy, cooler-than-normal, chance for showers and thunderstorms late this afternoon, highs in the lower 80's

Tonight

Mainly cloudy, mild, chance for showers and thunderstorms, lows in the upper 60’s

Tuesday

Mostly cloudy skies, a bit warmer, humid, chance for showers and thunderstorms, mid 80’s

Tuesday Night

Mostly cloudy, mild, chance for showers and thunderstorms, upper 60’s for lows

Wednesday

Partly sunny, warm, humid, chance for showers and thunderstorms, mid 80’s

Thursday

Mainly cloudy, warm, showers likely and possible thunderstorms, low-to-mid 80’s

Friday

Mostly cloudy, a bit cooler, chance for showers and thunderstorms, low 80’s

Saturday

Partly sunny, comfortably cool, still the chance for showers, near 80

Discussion

A frontal system will stall in the southern Mid-Atlantic region later today and low pressures will ride along the boundary zone keeping us on the unsettled side through much of the week. Temperatures will generally stay at or slightly below normal levels this week thanks in part to copious amounts of clouds in this weather pattern.

7:00 AM | Not bad at all for the middle of August...comfortable temperatures and humidity right into the weekend

6-Day Forecast

Today

Great day with mostly sunny skies and pleasant conditions, highs near 80 degrees

Tonight

Mainly clear, quite cool, lows in the mid-to-upper 50’s

Saturday

Still nice with mostly sunny skies and comfortable temperatures, low 80’s

Saturday Night

Partly cloudy, cool, low 60’s

Sunday

Partly sunny, a bit warmer and more humid, chance for showers and thunderstorms, low-to-mid 80’s

Monday

Mainly sunny, somewhat humid, chance for a shower or thunderstorm late, low-to-mid 80’s

Tuesday

Mostly cloudy, humid, showers and thunderstorms likely, low-to-mid 80’s

Wednesday

Partly sunny, warm, humid, showers and thunderstorms possible, mid 80’s

Discussion

A secondary cold frontal system passed through the region yesterday and ushered in a spectacular air mass for the end of the week. After a day full of sunshine with pleasant conditions, temperatures overnight will drop well down into the 50’s in suburban locations and nice weather will remain to begin the weekend. By Sunday and Monday; however, the humidity will build up somewhat and there will be an increased chance for showers and thunderstorms. That threat for showers and thunderstorms will continue on Tuesday and Wednesday as well as a cold front approaches the region.

7:00 AM | Low humidity air next few days

6-Day Forecast

Today

Mostly sunny skies this morning, partly sunny this afternoon, chance for a passing shower late in the day well north of the District, very comfortable temperatures and humidity levels, highs in the lower 80’s

Tonight

Becoming mostly clear and quite cool, lows by morning in the mid-to-upper 50’s

Friday

Spectacular with mostly sunny skies and comfortable temperatures, near 80

Friday Night

Mostly clear, quite cool, mid-to-upper 50’s

Saturday

Great weather continues with mostly sunny skies and pleasant temperatures, low 80’s

Sunday

Partly sunny, a bit warmer and more humid, chance for showers and thunderstorms, low-to-mid 80’s

Monday

Partly sunny, humid, chance for a shower or thunderstorm late, low-to-mid 80’s

Tuesday

Mostly cloudy, humid, showers and thunderstorms likely, low-to-mid 80’s

Discussion

A secondary cold frontal system will cross our region later today and it could set off a few late day and early evening showers across northern Maryland, but the immediate DC metro region will likely stay on the dry side as reinforcing cooler-than-normal air moves in. High pressure will take control of the weather on Friday and Saturday before another cold front approaches the region on Sunday. That front will stall in this area and the early part of next week will become unsettled as a result with a chance for showers and thunderstorms.

Video

httpv://youtu.be/MmQgP58mZfk

7:00 AM | Another refreshing air mass moves into the region on the heels of our heavy rain event

6-Day Forecast

Today

Cloudy early this morning with lingering showers possible, clearing skies during the mid-day and afternoon hours with high temperatures reaching the low-to-mid 80’s

Tonight

Becoming mostly clear and pleasantly cool, lows by morning not far from 60 degrees

Thursday

Spectacular with mostly sunny skies and comfortable temperatures, near 80

Thursday Night

Mostly clear, pleasantly cool, near 60

Friday

Great weather continues with mostly sunny skies and pleasantly cool temperatures, low 80’s

Saturday

Mostly sunny, still quite comfortable, low-to-mid 80’s

Sunday

Partly sunny, warmer, perhaps a bit more humid, mid 80’s

Monday

Mostly sunny, warm, mid-to-upper 80’s

Discussion

The threat for heavy rain will shift to the northeast of here today with New England getting pounded by intensifying low pressure along the Northeast US coastline. On the heels of this vigorous weather system that produced heavy rainfall in our area, yet another refreshing air mass for this time of year will push into the Mid-Atlantic region. Skies will clear later today along the I-95 corridor and the next couple of days will turn out to be spectacular with comfortable temperatures and humidity levels.

12:50 PM | ***Heavy rain event underway; isolated severe weather threat later today/early tonight***

[Latest NEXRAD radar image of the Northeast US; courtesy University of Wisconsin]

Discussion

Bands of heavy rain have pushed into the DC metro region and are on the doorstep of Philly as an unusually strong upper level trough of low pressure heads southeastward towards the Mid-Atlantic region. The heavy rain bands have prompted flash flood watches and warnings to be issued by the National Weather Service in the DC metro region and they very likely will be extended up the I-95 corridor as the day progresses (at least they should be). While the New York City metro region could receive heavy rainfall by late today, it is more likely in the overnight hours as an occluded frontal system and secondary low pressure system head that way. All of the big city metro regions in the Mid-Atlantic from DC-to-Baltimore-to-Philly-to-New York City have the potential to receive as much as 5 inches of rain by the time all is said and done from this vigorous weather system.

One of the interesting aspects of this unfolding weather event is the chill in the air for mid-August. A cool ocean flow of air has developed ahead of the developing low pressure system and that combined with cloud cover has kept temperatures way below normal for this time of year. Temperatures at the noon hour were 69 degrees at Dulles Airport in Virginia, 74 degrees at Reagan National Airport (DC) and only 77 degrees in Central Park, NY.

Warmer air is, in fact, trying to advance from the south and this process will increase the risk for severe storms later today and early tonight; especially, in the region between DC and Philly. It remains to be seen if any of the I-95 corridor region breaks into the "wwarm sector" air mass and experiences a surge in temperatures. The best chance for that to happen would be from the DC metro region to the Delmarva Peninsula. The heavy rain will not continue unabated through the day in the I-95 corridor. In fact, there is very likely to be a break in the action between today’s heavy rain and tonight’s heavy rain.

7:00 AM | ***Heavy rain today and tonight in the DC metro region with isolated severe weather possible as well; flash flooding a serious concern***

6-Day Forecast

Today

Cloudy and cooler with occasional showers and possibly a thunderstorm or two, rain will be heavy at times, highs only reaching the upper 70’s

Tonight

Showers and possibly a thunderstorm or two, rain will be heavy at times, mild, lows in the upper 60’s

Wednesday

Lingering showers possible early then becoming partly sunny with comfortably warm temperatures, low 80's

Wednesday Night

Mostly clear, pleasantly cool, near 60

Thursday

Mostly sunny, pleasant, low 80's

Friday

Mostly sunny, still quite comfortable, low 80's

Saturday

Mostly sunny, nice, low 80's

Sunday

Mostly sunny, warmer, a bit more humid, mid 80’s

Discussion

Our stretch of pleasant weather is over in the Mid-Atlantic region as copious amounts of moisture is streaming into the area ahead of an intensifying upper-level trough. This upper level trough will take on a “negative” tilt by early tomorrow morning as it pushes southeastward towards the I-95 corridor enhancing upper motion in this area. The combination of the intensifying upper level trough, an impressive low-level jet and high moisture content in this air mass will help generate significant rainfall for the Mid-Atlantic region into early Wednesday with two to as much as five inches possible in the DC metro region. Along with the potential for flash flooding and torrential downpours today, isolated severe weather is a threat throughout the DC metro region at the end of the day and into early tonight. On Wednesday, the heavy rain threat will shift northeastward into New York and New England where a wild day of weather can be expected.

Video

httpv://youtu.be/e8pqP5tSUBQ

2:15 PM | **Heavy rain event later tomorrow into early Wednesday; new tropical wave in the eastern Atlantic**

[GFS 500 mb forecast map for Wed AM; courtesy NOAA]

Discussion

Our stretch of pleasant weather will be coming to an end shortly in the Mid-Atlantic region as moisture beings to increase ahead of an intensifying upper-level trough. This upper level trough will take on a “negative” tilt by Wednesday morning (see forecast map) as it pushes southeastward towards the I-95 corridor enhancing upper motion in this area. The combination of the intensifying upper level trough, an impressive low-level jet and high moisture content will help generate significant rainfall for much of the Mid-Atlantic and Northeast US between tomorrow morning and late Wednesday with 2-4 inches in most locations and up to 5 inches or so possible in isolated locations. The heaviest rainfall for the I-95 corridor from DC-to-Philly-to-NYC will occur from late tomorrow into early Wednesday. During the day Wednesday, the heavy rain threat will shift northeastward into New England where a wild day of weather can be expected. Along with the potential for flash flooding, there is a threat for isolated severe weather in the Mid-Atlantic and Northeast US during this upcoming weather event. One final note, there is now a new tropical disturbance just off the west coast of Africa that bears watching as we are now approaching the heart of the Atlantic Basin tropical season (i.e., mid-August through September).

[Visible satellite image of the eastern Atlantic; courtesy Penn State eWall]