Area Forecast Discussion
Issued by NWS Charleston, WV

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000 FXUS61 KRLX 231109 AFDRLX Area Forecast Discussion National Weather Service Charleston WV 609 AM EST Tue Jan 23 2018 .SYNOPSIS... Low pressure system exits northeast, but remains unsettled through Wednesday. Warmer to end the week. Cold front next weekend. && .NEAR TERM /THROUGH TONIGHT/... As of 555 AM Tuesday... Last of the showers to move through the northeast mountains over the next couple of hours. Dried out the forecast for the bulk of the morning and afternoon hours today before the low level moisture returns. As of 250 AM Tuesday... Line of showers weakening as it passes the I79 corridor this morning. Still have lingering showers behind this line, and the low level cold air advection lagging behind the cold front a bit, but will see slowly falling temperatures through the day. The broad upper level cyclone has pulled in dry air that will provide breaks in the clouds for the first part of the day, but the low level moisture returns and timed this with the higher RH values in the 925mb layer and the continuing cold air advection. This will last through tonight, and ramp the sky cover grids to overcast after 00Z Wednesday. That low level moisture should end up deep enough to warrant light isolated to scattered snow showers, most persistent in the mountains. Amounts in the near term will be light, with the only amounts over an inch in the highest ridges. Winds will be on the increase over the next several hours in descending air in the cold advection process. Will be transferring momentum down to the surface from around 800mb, but should stay well below advisory criteria. Highest elevations will receive the highest gusts. && .SHORT TERM /WEDNESDAY THROUGH FRIDAY/... As of 325 AM Tuesday... A 500mb shortwave trough will swing through on Wednesday. Moisture is fairly limited, but with 850mb temps in the -10C range, should still be able to get some light snow showers...especially across the northern mountainous counties. The snow showers should taper off from west to east overnight. Still have some cold air advection lingering Thursday morning, so cannot rule out some lingering flurries, but opted to not include them at this point since moisture will be limited and the air is not super cold. Surface flow turns SW Thursday into Friday with a surface high drifting toward the NC/VA coast. This will bring a warming trend to end the work week. && .LONG TERM /FRIDAY NIGHT THROUGH MONDAY/... As of 320 AM Tuesday... Models remain fairly unhelpful for weekend system. The GFS is much faster with the system, bringing a cold front through late Saturday and Saturday night. The GFS is fairly progressive and is dry by midday Sunday. The ECMWF is much slower with this system, as it tries to cutoff the 500mb flow and pulls a southern stream surface low up the Appalachian spine Sunday into Monday. With the stronger system on the ECMWF -- enough cold air would arrive for a changeover to snow Sunday night into Monday. The GFS is much warmer... and mainly dry at this time. For now did not stray far from a consensus blend, having high chance POPs Saturday night into Sunday. && .AVIATION /12Z TUESDAY THROUGH SATURDAY/... As of 555 AM Tuesday... Ceilings to scatter out west to east through the daytime hours with strong surface wind gusts out of the west southwest in the 25-35kt range. These gusts will peak in the 16Z-22Z time frame depending on terminal. Expecting MVFR ceilings to return to the region as the low pressure system lifts out to the northeast. Isolated to scattered rain showers develop in this scenario, gradually changing to a rain/snow mix and then all snow tonight as temperatures continue to fall. Only the mountain terminals carry chances high enough for prevailing conditions at this point. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z WEDNESDAY... FORECAST CONFIDENCE: Medium to high. ALTERNATE SCENARIOS: May need more prevailing rain/snow after 00Z Wednesday. 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. DATE TUE 01/23/18 UTC 1HRLY 10 11 12 13 14 15 16 17 18 19 20 21 EST 1HRLY 05 06 07 08 09 10 11 12 13 14 15 16 CRW CONSISTENCY H H H H H H M M M M L L HTS CONSISTENCY H H H H H M M M M M L L BKW CONSISTENCY H M H H H H H H H H M M EKN CONSISTENCY H M H H H H H H H H L M PKB CONSISTENCY H H H H H H L L M M L L CKB CONSISTENCY L H H H H H H H H H L L AFTER 12Z WEDNESDAY... IFR snow possible in mountain terminals Wednesday/Wednesday night. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...None. OH...None. KY...None. VA...None. && $$ SYNOPSIS...MZ/26 NEAR TERM...26 SHORT TERM...MZ LONG TERM...MZ AVIATION...26 is the U.S. government's official web portal to all federal, state and local government web resources and services.