Area Forecast Discussion
Issued by NWS Charleston, WV

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834 FXUS61 KRLX 021435 AFDRLX Area Forecast Discussion National Weather Service Charleston WV 935 AM EST Fri Dec 2 2016 .SYNOPSIS... Cooler high pressure to end the work week. Weak upper trough late Sunday into Sunday night. Warm front Monday night Tuesday. Milder mid week. && .NEAR TERM /THROUGH TONIGHT/... As of 925 AM Friday... Low stratus trying to slowly advance southward this morning as weak CAA beneath subsidence inversion lingers today. Despite the moisture depth only 25 to 50 mb deep...think this will be tough to break this afternoon, especially as one travels north. Think the Nam 4km has a good handle on this, so used this as a base to augment sky grids. This allows stratus shield to expand south as the day progresses...into southern WV and the remainder of northeast KY. Meanwhile, southwest VA may keep the sun for the bulk of the afternoon. All of this means an adjustment to forecast highs to go a bit lower than previous forecast while still showing a bit of a gradient from southwest VA into southern WV. So...areas along and north of I64 corridor will struggle to see much in the way of a rise today, essentially nearly steady state in the upper 30s. Areas further south should see rises into the lower to mid 40s. We are still expecting some light snow showers or snizzle across the northern mountains this afternoon which may dust the ride tops. Though there is a very very marginal setup for ice crystals given the cloud top temp of -6 to -8C. As of 330 AM Friday... Overall, no major changes were necessary to the near term forecast period. WNW flow, with lots of low level moisture will continue across the CWA in the near term period. A weak upper impulse will move across the northern zones on Friday afternoon/evening, with some light precip possible across these zones, however, best location for anything is across the northern mountain zones in upslope flow, with mainly clouds or -dz more likely elsewhere across north central WV. as there is not expected to be enough lift/moisture to work with. May be a bit of a break in the clouds late tonight as high pressure continues to nudge in from the west, but not expecting a total clearing. && .SHORT TERM /SATURDAY THROUGH MONDAY NIGHT/... As of 330 AM Friday... Upslope rain and snow showers in the mountains diminish early Saturday morning, as high pressure builds toward the area with drier air. Low level northwest flow does continue, but the cold advection ceases as the thermal trough passes. The high crosses early Sunday morning, followed by the upper level ridge. The next upper level short wave trough crosses Sunday afternoon into Sunday night. This looks like a split system with little surface reflection, with most of the associated precipitation passing to the north and to the south of the forecast area. Therefore have only slight chance to chance PoPs, highest south, Sunday afternoon and night. High pressure crosses late Sunday night into Monday, followed by upper level ridging Monday evening. An upper level short wave trough digging into northwest Mexico early this morning, closes off there Saturday morning, and then ejects out into TX Monday morning, and then dampens out as it moves up the Ohio Valley Tuesday morning. This and its attendant surface low pressure system and associated warm advection and dynamics should result in rain overspreading the forcast area quickly as dawn Tuesday approaches. Temperatures were kept generally close to guidance. Light snow showers are possible Sunday night in northern WV, especially in the mountains. Temperatures should rise above freezing as the next system approaches Monday night, but did allow for some light snow at the front end in the northern WV mountains Monday night. && .LONG TERM /TUESDAY THROUGH THURSDAY/... As of 330 AM Friday... Dampening upper level short wave trough lifts through the area on Tuesday, allowing rain to taper off from southwest to northeast Tuesday midday and afternoon. Beneath upper level southwest flow in the wake of the dampening system, a lack of cold air means any lingering showers or drizzle in the wake of the system Tuesday night will remain liquid. Weak high pressure crosses on Wednesday, but lingering low level moisture, and the short break between systems, results in a small chance for rain remaining in the forecast.. Models start to diverge on the timing of the next system later in the week in this active weather pattern. Went with a compromise, with a strong cold front sweeping through the area sometime on Thursday. Strong cold advection following the front will change mainly upslope rain showers over to snow showers in the mountains sometime Thursday, before ending Friday morning. Temperatures close to guidance, with very cold air moving into the area by Friday, when models concur on h85 temperatures of 18 to 20 C below 0. This would be the coldest air of the season so far, with the new day 7 highs at or below freezing Friday. && .AVIATION /15Z FRIDAY THROUGH TUESDAY/... As of 610 AM Friday... Still an overcast deck across much of the area, with a clearing across southwest Virginia, northeast KY, and southern WV. As with previous forecast, still expecting this to fill back in particularly after 14Z, although aforementioned areas across the south may remain VFR. Could be some improvement to low VFR after 21Z many locations. Otherwise, northwesterly flow will increase today, with gusty winds developing after 17Z, with gusts generally in the teens across the lowlands, and in the 20s higher terrain. In addition, occasional -shsn across the northern mountains, creating brief restrictions. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z SATURDAY... FORECAST CONFIDENCE: Medium. ALTERNATE SCENARIOS: Timing of category changes in clouds may vary. Possible clouds could break up more, resulting in more widespread VFR than currently 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. UTC 1HRLY 12 13 14 15 16 17 18 19 20 21 22 23 EST 1HRLY 07 08 09 10 11 12 13 14 15 16 17 18 CRW CONSISTENCY H H H L L H H H H H H L HTS CONSISTENCY H M H H H H H H M H M L BKW CONSISTENCY M H H H H H H H H H H M EKN CONSISTENCY L H L L L L H H H M M L PKB CONSISTENCY H H L M H H H H H H L L CKB CONSISTENCY H H L H H H M H H H H L AFTER 12Z SATURDAY... Brief IFR possible in -shsn at higher mountain ridges into Saturday afternoon. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...None. OH...None. KY...None. VA...None. && $$ SYNOPSIS...TRM/SL NEAR TERM...SL/30 SHORT TERM...TRM LONG TERM...TRM AVIATION...SL is the U.S. government's official web portal to all federal, state and local government web resources and services.