Area Forecast Discussion
Issued by NWS Charleston, WV

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000 FXUS61 KRLX 071759 AFDRLX Area Forecast Discussion National Weather Service Charleston WV 1259 PM EST Thu Dec 7 2017 .SYNOPSIS... Moisture starved cold front moves through today. Low pressure and cold front likely to bring snow showers Saturday afternoon and night, and early next weak. && .NEAR TERM /THROUGH TONIGHT/... As of 850 AM Thursday... Light snow showers providing a light coating on grassy and elevated surfaces over the Tri State area, moving east northeastward thanks to a modest mid level saturated layer and a stout 700hPa vort max. Have adjusted the POPs accordingly and is best represented by the HRRR at this time. As of 220 AM Thursday... A moisture starved reinforcing cold front will push through the area today. 850 MB temperatures are in prime crystal growth territory by this afternoon and evening with an upslope wind component. Moisture depth is fairly shallow however, with a brief depth increase right around the front. Will include some small pops along the front, enhanced a bit in the northern mountains, and remaining behind the front in the WV mountain upslope region. With limited moisture, no significant snow accumulations are expected. Based on MOS guidance performance on Wednesday, will go on the lower side of guidance. && .SHORT TERM /FRIDAY THROUGH SUNDAY NIGHT/... As of 345 AM Thursday... A coastal system passes by to our south and east Friday and Friday night...leaving the area under a partly cloudy sky but remaining cold. Focus on the short term periods continues to center on Saturday, with a s/w trof amplifying the mean longwave trof across. The associated surface low moves into the Great Lakes which will drive a cold front thru as the day progesses. There will quite a bit of dry air near the surface to overcome, which will initially keep most of the flakes as virga. As saturation occurs and wetbulbing effects take hold, temps will drop and snow should reach the ground. The problem is this may occur after most of the forcing has ceased, leaving more flurries than light snow/snow showers especially for the western WV Lowlands which should see a spike in temps into the upper 30s in the western Lowlands before the front passes. Winds will be gusty ahead of the front and behind the front...on the order of 20 to 30 kts. A brief northwest flow event unfolds behind the front for Saturday night, with favorable trajectories off Lake Michigan keeping snow showers going across the mountains. There is some disagreement with how fast this gets cut off via llvl WAA. Nevertheless, expect 2 to 4 inches across the favorable high elevations with a general 1 to 2 inches for the mountain valleys. Some sun is expected on Sunday though clouds will be delayed across the north until the llvl thermal trof passes. Temps will remain quite chilly, with readings 12 to 15 degrees below normal. Some mid and high level moisture will streak thru on northwest flow aloft Sunday night. && .LONG TERM /MONDAY THROUGH WEDNESDAY/... As of 400 AM Thursday... There will be a brief respite from the cold on Monday as the WAA overtakes the area on gusty southwest winds. This should allow temps to approach more typical values for this time of year. The next system arrives Monday night in the form of a cold front with gusty winds and snow showers breaking out overnight with another s/w trof diving in. Post frontal northwest flow should enact a more robust event for Tuesday than the one expected this Saturday. Some accumulations are expected in the mountains with some skiffs across the Lowlands. Temps were held on the cold side of the guidance envelope. Another clipper looks to arrive Wednesday with a shot of light snow. && .AVIATION /18Z THURSDAY THROUGH TUESDAY/...
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As of 1250 PM Thursday... A mid level disturbance has been producing light snow across the area this morning and early afternoon, which will also continue over the northern terminals later this afternoon and this evening. However, no restrictions are expected from this except at EKN where ceilings will eventually drop into the MVFR range of 2-3kft. Visibilities will stay above 6SM. Expect wind gusts to 22kts possible through 00Z Friday. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z FRIDAY... FORECAST CONFIDENCE: High. ALTERNATE SCENARIOS: Brief MVFR in light snow is possible. EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY OF WFO FORECAST TO AVAILABLE MODEL INFORMATION: H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS. L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. UTC 1HRLY 18 19 20 21 22 23 00 01 02 03 04 05 EST 1HRLY 13 14 15 16 17 18 19 20 21 22 23 00 CRW CONSISTENCY H H H H H H H H H H H M HTS CONSISTENCY H H H M H H H H H H H M BKW CONSISTENCY H H H H H H H H H H H M EKN CONSISTENCY H M H H H M H H H H H M PKB CONSISTENCY H H M H H H H H H H H M CKB CONSISTENCY M H H H M H H H H H M M AFTER 18Z FRIDAY... IFR possible in snow showers Saturday and Saturday night.
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&& .RLX WATCHES/WARNINGS/ADVISORIES... WV...None. OH...None. KY...None. VA...None. && $$ SYNOPSIS...RPY/30 NEAR TERM...RPY/26 SHORT TERM...30 LONG TERM...30 AVIATION...26

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