Area Forecast Discussion
Issued by NWS Sterling, VA

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000 FXUS61 KLWX 250903 AFDLWX Area Forecast Discussion National Weather Service Baltimore MD/Washington DC 403 AM EST Sat Nov 25 2017 .SYNOPSIS...
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A cold front crosses the region today and moves east of the Chesapeake Bay Saturday night. High pressure moves back into the area Sunday and remains in control through the middle part of the upcoming work week.
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&& .NEAR TERM /UNTIL 6 PM THIS EVENING/...
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A cold front moving through the Midwest early this morning will bring another shot of cooler air to us. But not before we squeeze in a warmer than normal day today, although clouds will be on the increase. The front will bring little if any precip to the area. Currently thinking there will be a few sprinkles east of the mountains and thats about it. MOS guidance of nearly all sorts keeps PoPs below 10 percent, and convective allowing meso ensembles and models show varying degrees of small broken bands of very weak echos moving east across the region.
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&& .SHORT TERM /6 PM THIS EVENING THROUGH MONDAY NIGHT/...
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Behind the frontal passage, west to northwest winds will increase appreciably Saturday night, resulting in upslope rain showers transitioning to snow showers during the evening in the favored locations, with minor accumulations of an inch or less possible thru sunrise Sunday. Temperatures will settle down in the 30s for most, near 40 degrees in the cities, and some upper 20s in the western highlands. Breezy conditions Sunday morning will start to subside during the afternoon has high pressure builds in from the west southwest. Expect dry conditions to finish out the weekend with highs in the mid to upper 40s, to near 50 in the metro area. Low temperatures Sunday night will fall down in the mid to upper 30s for most.
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&& .LONG TERM /TUESDAY THROUGH FRIDAY/...
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On Tuesday, an upper level ridge axis will be over our region. At the surface, high pressure will be centered just off the coast, with broad southwesterly flow over our region. This will result in mild conditions with temperatures perhaps topping 60, and no precipitation is expected. A northern stream shortwave trough will pass by to the north Tuesday night. The high will slip a bit further east and stretch out to our south, with winds turning a bit more westerly as a weakening cold front approaches from the northwest. It will remain mild with lows staying above freezing, but no precipitation is expected. The northern stream shortwave trough will move away to the northeast Wednesday as another ridge axis approaches from the west. The cold front moving in from the northwest on Tuesday night will stall and die out as surface high pressure rebuilds over the region. Mild and dry conditions will continue to prevail. A ridge axis will move overhead Wednesday night as a southern stream shortwave begins to approach from the southwest. At the surface, high pressure will remain in control as it shifts northeastward across the area. With mild air mass remaining in place, temperatures will likely stay above freezing in most areas once again. The ridge axis will move northeast of us on Thursday as a much stronger shortwave trough dives southeastward over the midwest and the southern stream shortwave weakens over the Carolinas. Surface high pressure will retreat eastward off the coast as a cold front approaches from the northwest. Increasing clouds will likely limit warmth by this time, with temps less likely to reach 60, and the chance for rain, though low, will start to creep up. The southern stream shortwave will pass off the east coast Thursday night as the deepening trough to our west continues to approach our area. The approaching surface cold front will begin to enter our area. Mild temperatures will remain (in fact likely the mildest night of the week thanks to cloud cover), but the chance of rain will increase substantially. The strong upper level trough and surface cold front from the midwest will cross the region Friday. Temperatures will slide back towards normal and the chance of rain will linger.
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&& .AVIATION /09Z SATURDAY THROUGH WEDNESDAY/...
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VFR conditions expected across the terminals for the next 24 hours. Clouds will be on the increase with the cold front today but VFR VIS/CIGs expected as any shower activity will remain limited. The cold front will pass through the terminals during the afternoon and exit to the east Saturday evening. Winds will turn gusty out of the west northwest tonight, averaging 10 to 15 knots with gusts up to 20 knots. Winds will subside during the day Sunday with clearing skies and dry conditions forecast, thus no flight restrictions expected. VFR conditions are expected to prevail through Wednesday as high pressure controls our weather pattern.
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&& .MARINE...
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Light south to southwest winds today will turn westerly later today following the cold front. Small Craft Advisory conditions expected to begin this evening and continue through Sunday as gusty northwesterly winds increase behind the front. Conditions on the waters should remain below SCA levels on Monday. Tuesday, southerly channeling on the back side of the high may result in small craft advisory conditions. These may continue Wednesday as a weak cold front pushes into the region.
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&& .LWX WATCHES/WARNINGS/ADVISORIES...
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DC...None. MD...None. VA...None. WV...None. MARINE...Small Craft Advisory from 9 PM this evening to 5 PM EST Sunday for ANZ530>543.
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&& $$ SYNOPSIS...CS NEAR TERM...CS SHORT TERM...CS LONG TERM...RCM AVIATION...CS/RCM MARINE...CS/RCM

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