Area Forecast Discussion
Issued by NWS Sterling, VA

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000 FXUS61 KLWX 260758 AFDLWX Area Forecast Discussion National Weather Service Baltimore MD/Washington DC 358 AM EDT THU MAY 26 2016 .SYNOPSIS...
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High pressure will remain over the area through the end of the week. Low pressure may affect the region Memorial Day through Tuesday. Weak high pressure builds for the middle of next week.
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&& .NEAR TERM /TODAY/...
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As of 3am...1023mb surface high is off the Carolina coast. Light south winds are across the LWX CWA with 24hr trend in dewpoints up 2 to 3 degrees. A weak shortwave trough axis is apparent in water vapor imagery over IN/KY. This trough will drift east to the central Appalachians today. Weak height falls ahead of this shortwave trough will promote convective growth (the cap from yesterday will be absent) first in terrain. Scattered coverage eventually develops across the area with initiation in the east from bay breeze boundaries. Lapse rates are quite poor/moist in the mid-levels and shear is less than 10 knots, so these will be pulse garden variety thunderstorms with no severe risk. Maxima very similar to Wednesday (mid 80s) though dewpoints increasing into the 60s will result in max heat indices of 90F.
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&& .SHORT TERM /TONIGHT THROUGH SATURDAY NIGHT/...
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Thunderstorm activity continues into the evening in merging boundaries. The upper trough axis moves into the area overnight, which may aide continued overnight thunderstorms. Minima mid to upper 60s with dewpoints in the mid 60s. Increasing moisture trend continues Friday with dewpoints reaching 70F. Mid to upper 80s maxima will result in low 90s heat indices. Diurnal scattered thunderstorm coverage that persists through the evening expected again. Warm night with minima mid to upper 60s. Upper level ridge builds into the area from the east north of a developing low off the SC coast. Associated height rises create a subsidence inversion and greatly limit convective development. Just low chances in the Allegheny Mountains. Maxima mid 80s again with dewpoints down into the mid 60s with upper 80s heat indices.
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&& .LONG TERM /SUNDAY THROUGH WEDNESDAY/...
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Moisture will be on the increase for the second half of the holiday weekend as a weak area of low pressure slowly tracks north over the Carolinas. Superblend continues to project highs in the mid/upper 70s while Euro/GFS forecast low 80s. There`ll be chances for showers/thunderstorms Sunday-Wednesday but severe threat looks low to non-existant. GFS shows the deepest moisture advecting over the Blue Ridge Wednesday so perhaps there could be a heavy rain threat? But that is seven days away. Looking really far out in time long range both models are projecting a cold front moving onto the east coast at the end of next week.
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&& .AVIATION /THURSDAY THROUGH MONDAY/...
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Light southerly flow and VFR conditions continue into the afternoon when diurnal thunderstorms are expected to form (first storms west of DC metros in the terrain). IFR conditions expected in heaviest activity. Southerly flow continues through Saturday. Similar thunderstorms pattern Friday compared to Thursday. High pressure limits thunderstorms Saturday. Potential for showers/thunderstorms increases late Sunday evening into early next week with sub-VFR conditions in storms. Otherwise VFR conditions expected in the extended portion of the forecast.
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&& .MARINE...
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Light southerly flow persists through Saturday as high pressure lingers near Bermuda. Will need to look out for southerly channeling on the main waters, but no SCA expected as of this time. Increasing chances on the waters for showers and thunderstorms Sunday and Monday.
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&& .LWX WATCHES/WARNINGS/ADVISORIES... DC...None. MD...None. VA...None. WV...None. MARINE...None. && $$ PRODUCTS...BAJ/WOODY!

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