|Dew Point:||21.2°F (-6.0°C)|
|Sea Level Pressure:||28.56" (966.9 mb)|
Partly CloudyLow: 50
SunnyHigh: 70 Low: 64
Slight Chance Rain Showers then Chance Showers And ThunderstormsHigh: 80 Low: 65
Slight Chance Rain Showers then Mostly SunnyHigh: 81 Low: 63
Chance Showers And ThunderstormsHigh: 82 Low: 66
Partly cloudy, with a low around 50. East wind around 3 mph.
Sunny, with a high near 70. Southeast wind 5 to 10 mph.
A slight chance of rain showers after 2am. Partly cloudy, with a low around 64. South wind around 10 mph. Chance of precipitation is 20%.
A slight chance of rain showers before 2pm, then a chance of showers and thunderstorms. Partly sunny, with a high near 80. Southwest wind around 12 mph, with gusts as high as 21 mph. Chance of precipitation is 30%.
A chance of showers and thunderstorms. Partly cloudy, with a low around 65. West wind 10 to 14 mph. Chance of precipitation is 30%.
A slight chance of rain showers before 8am. Mostly sunny, with a high near 81. Chance of precipitation is 20%.
Mostly clear, with a low around 63.
A chance of showers and thunderstorms after 8am. Mostly sunny, with a high near 82. Chance of precipitation is 30%.
A chance of showers and thunderstorms before 8pm. Partly cloudy, with a low around 66. Chance of precipitation is 30%.
... Canadian high pressure will build overhead through tonight before moving offshore Wednesday. A warm front will pass through the area Wednesday night into Thursday. A cold front will approach Thursday night before stalling out nearby for Friday and Saturday. The boundary may hang around nearby for the rest of the weekend into early next week, causing the possibility of unsettled conditions.
NEAR TERM /THROUGH WEDNESDAY/... Canadian high pressure will continue to build overhead through tonight bringing cool conditions for this time of year along with low humidity. There will be some high clouds moving through in the westerly flow aloft, but with the upper-level ridge axis to our west...the cloud deck should be thin due to subsidence. Min temps tonight range from the 40s in the colder valleys and rural areas to the mid/upper 50s in downtown Washington and Baltimore.
SHORT TERM /WEDNESDAY NIGHT THROUGH THURSDAY NIGHT/... The high will slowly move offshore Wednesday and a southerly flow will develop during the afternoon. There will be a slight increase in atmospheric moisture due to the southerly flow and warm advection. This may result in a thin stratocu deck underneath the subsidence inversion, but there should still be plenty of sunshine as well since the thin layer should mix out from daytime heating. Max temps will be in the lower to middle 70s for most locations.
The high will continue to move offshore Wednesday night and a warm front is expected to approach the area from the west overnight. The warm front will pass through the region Thursday morning. Weak isentropic lift and limited elevated instability ahead of the warm front may be enough to trigger a few showers, especially overnight Wednesday into Thursday morning. A rumble of thunder cannot be ruled out as well, but confidence is low at this point since the lifting mechanism will be weak.
For Thursday afternoon, a southwest flow behind the warm front will bring a return to hotter and more humid conditions. Max temps will top off well into the 80s for most areas, and some areas may even approach 90 degrees. The increased heat and humidity will lead to an unstable atmosphere, and with our area between an upper-level high to the south and upper-level low to the north, there should be moderate amounts of deep layer shear. At the same time, a cold front will be approaching from the north but latest guidance keeps this boundary well to our north during peak heating before it drops down later Thursday night. Therefore, the timing of the boundary and peak heating are offset a bit. Having that been said, it will be a differential advection pattern (northwest flow aloft and southwest flow at the low-levels), which supports the development of convective systems (MCS). Will carry the chance for showers and thunderstorms Thursday afternoon and evening, and with the instability and shear in place, some of those storms could be severe. However, confidence still remains low due to uncertainty in timing of a convective system and also with the cold front arrival being after peak heating.
The boundary will settle overhead late Thursday night, and a shower is possible, but most areas will likely be dry due to the loss of heating.
LONG TERM /FRIDAY THROUGH TUESDAY/... Upper level ridging will remain centered over the southeastern Friday and Saturday. Meanwhile, a cold front will be located near or south of the area Friday. With ridging shunted to the west, this should lead to slightly cooler and less humid conditions. A narrow ridge of surface high pressure will move overhead Friday night.
A low pressure system will be moving north of the Great Lakes on Saturday. The system's warm sector will translate eastward through the day, although there's some uncertainty if the upper ridge will remain strong enough to suppress any convection. The best chance of any showers and storms will be over the terrain and closer to the Pennsylvania border. The shortwave trough aloft will suppress the ridge to the south, resulting in a more zonal flow aloft across the Mid Atlantic for the second half of the weekend. This will slow the cold front's southward progress and allow it to waver across the area into early next week. This will result in mainly diurnal chances of showers and thunderstorms Sunday into Monday. There's some consensus on another shortwave being able to shove the front south by Tuesday, with high pressure to follow (briefly). With the absence of any strong pushes of Canadian air, temperatures will likely run above normal through early next week.