Area Forecast Discussion
Issued by NWS Charleston, WV

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976 FXUS61 KRLX 200736 AFDRLX Area Forecast Discussion National Weather Service Charleston WV 336 AM EDT Tue Mar 20 2018 .SYNOPSIS... Low pressure system will bring unsettled weather to the region into Thursday. High pressure takes control late week with another low pressure system next weekend. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... As of 1030 PM Monday... Allowed for a quicker break in the steadier rains overnight per radar trends and latest hi res models. As of 745 PM Monday... Slowed onset of rain a bit for this evening, based on dry low levels and radar trends. While pops are high, this looks like a mainly light rain event thru the overnight hours. This will pivot northward overnight with a bit of a lull working in across the area by dawn, followed by areas of light rain or drizzle developing as the day progesses. A shot of freezing rain still looks good across far eastern Randolph County tonight with around a tenth of accretion forecast. As of 213 PM Monday... An area of low pressure, currently over the mid-Mississippi Valley, will move into the region on Tuesday. Associated clouds and precipitation will spread east early tonight and then continue across the region through much of Tuesday. With little in the way of clouds today, temperatures have warmed a few degrees above what was expected. These warmer than expected readings may play a role in what form the precipitation falls across the highest elevations tonight into Tuesday. Dewpoint temperatures are still quite low and not sure if the latest models have a handle on the evaporative cooling that should take place as the precipitation pushes into the area. Have leaned toward the cool side of guidance tonight. However, have increased the readings by a degree or so to reflect the warmer afternoon temperatures. Even with the lowest portion of the atmosphere cooling to freezing or below, models suggest temperatures just above the surface will remain above freezing through the period. This results in the precipitation becoming a wintry mix across the highest elevations of our northern West Virginia mountain counties after midnight tonight and then continuing into Tuesday. Could see a tenth or so of freezing rain with some sleet and snow as well. After consultation with our neighbors, have issued a Winter Weather Advisory mainly for ice for tonight into Tuesday. && .SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/... As of 325 AM Tuesday... Snow will continue across the area on Wednesday as an upper level low and surface low continue to wrap rounds of precipitation across the region. Could be some heavier bands at times on Wednesday, and current thinking is this will generally be the case across the central mountains, and across Ohio, just north of our CWA, but any sort of heavy bands are very difficult to predict, and with the flip flopping of models over time, leads to even less confidence in pinpointing heavier bands. Overall, leaned towards WPC guidance with respect to snowfall totals, which leans heavily on the NAM and SREF. There is a bit of a concern as to how much snow will actually be able to accumulate across our lowland counties on Wednesday, with models suggesting boundary layer temperatures hovering around the 40 degree mark, or warmer. Elected to lower temperatures a bit Wednesday afternoon from the blended guidance, but even with doing that, still looking at minimal accumulations across much of the lowland counties Wednesday afternoon, but with moderate accumulations continuing across the mountains at times. Precipitation will gradually taper off across the area Wednesday evening as the low moves off to the east, with just some light upslope snow showers lingering across the higher terrain through early Thursday. && .LONG TERM /FRIDAY THROUGH MONDAY/... As of 330 AM Tuesday... Overall dry through much of Friday with high pressure in control. Weather becomes more unsettled from the weekend onward, as a low pressure system, and multiple upper waves move through the area. Precipitation could be heavy at times early next week with Gulf moisture surging into the region. && .AVIATION /08Z TUESDAY THROUGH SATURDAY/... As of 200 AM Tuesday... An area of rain is lifting through the forecast area early this morning. As upper and surface lows drift in today expect ceilings to lower with MVFR area wide. Expect a decrease in shower activity after this first area moves through, but then will be on the increase again by late afternoon as better forcing arrives. Rain will change over to snow tonight as colder air arrives with MVFR to IFR expected. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z WEDNESDAY... FORECAST CONFIDENCE: Medium. ALTERNATE SCENARIOS: Timing of precipitation and associated restrictions may vary from forecast. 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 03/20/18 UTC 1HRLY 06 07 08 09 10 11 12 13 14 15 16 17 EDT 1HRLY 02 03 04 05 06 07 08 09 10 11 12 13 CRW CONSISTENCY H H H H H L L H H H H M HTS CONSISTENCY M H H H H H H H H H H M BKW CONSISTENCY H M H M H H H H H M M L EKN CONSISTENCY H H H H M H H M H L H L PKB CONSISTENCY H H H M M M M H L H H L CKB CONSISTENCY H H H H M H H H M M M L AFTER 06Z WEDNESDAY... IFR possible in precipitation through Thursday. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...Winter Storm Watch from late tonight through Wednesday evening for WVZ008>011-016>020-027>034-039-040-515>519-521-524- 525. Winter Weather Advisory from 1 AM to 8 PM EDT Wednesday for WVZ005>007-013>015-024>026. Winter Weather Advisory until 2 PM EDT this afternoon for WVZ523-526. Winter Storm Watch from this evening through Wednesday evening for WVZ520-522-523-526. OH...Winter Storm Watch from late tonight through Wednesday evening for OHZ066-067-075-076-084-085. Winter Weather Advisory from 1 AM to 8 PM EDT Wednesday for OHZ083-086-087. KY...Winter Weather Advisory from 1 AM to 8 PM EDT Wednesday for KYZ101>103-105. VA...Winter Storm Watch from late tonight through Wednesday evening for VAZ003-004. && $$ SYNOPSIS...MZ/SL NEAR TERM...JSH/30 SHORT TERM...SL LONG TERM...SL AVIATION...MZ is the U.S. government's official web portal to all federal, state and local government web resources and services.