140 FXUS61 KRLX 091817 AFDRLX Area Forecast Discussion National Weather Service Charleston WV 217 PM EDT Tue Oct 9 2018 .SYNOPSIS... High pressure tonight. Continued warm through Wednesday. Cold front crosses Thursday as the remnants of Michael pass to the east. Much cooler in its wake for Friday and the weekend. && .NEAR TERM /THROUGH WEDNESDAY/... As of 214 PM Tuesday... High pressure continues in control tonight with humid and warm conditions prevailing through Wednesday. Modest to strong boundary layer winds around 25 knots will prevent widespread fog formation tonight. Models depict a plume of moisture lifting north as a warm front Wednesday, ahead of an associated cold front. Coded low chance PoPs not trusting dry weather suggested by models. Additional, showers and thunderstorms, some with heavy rain, will be possible along the cold front, to reach southeast OH by the end of the period 12Z Thursday. Summer-like temperatures will continue tonight, but a little cooler on Thursday due to cloud cover and cooling showers. Minor changes to previous temperature forecast noted. && .SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY NIGHT/... As of 420 AM Tuesday... The summer weather pattern breaks down this period, as a significant air mass change takes place. A northward moving tropical system and southward moving canadian air mass both spell positive poleward heat flux. Wednesday will already be a bit cooler than recent days, simply on account of increasing and thickening cloudiness from the remnants of Michael approaching from the south, and the cold front approaching from the west. Stratus along the eastern slopes may lift for a time Wednesday, before returning, as upslope rain develops in the southeast flow ahead of the remnants of Michael approaching from the south, and the cold front approaching from the west. The Appalachians form a natural impedance zone for somewhat of a PRE ahead of Michael. The NAM12 cranks out over an inch Wednesday afternoon into Wednesday evening over the central Appalachians, but neither the global nor the other high res models /WRFs/ support this. Models do depict an associated upper level short wave trough moving northward through the central Appalachians Wednesday, that than exits to the northeast Wednesday night. A lull in the rain takes place overnight Wednesday night, as a result. Showers arrive from the west early Thursday morning, ahead of the advancing cold front. Thunderstorms are possible in the central Appalachians, ahead of the cod front, if enough heating can take place before the front arrives. However, this heating should be limited, as will bulk shear, so thunderstorms are not expected to get very strong, but locally heavy rainfall is still possible, given widespread PW values just over two inches. However, the heaviest of the rainfall directly associated with Michael is progged to stay east of the forecast area. Will trim back the heavy rainfall highlight in the HOW to only include the WV mountains. Much cooler air moves in behind the cold front Thursday night, and widespread 40s are expected for lows Friday morning, for the first time this season. Highs Friday will be lower than lows recent nights. Another upper level short wave trough will move through Friday night, possibly producing light rain showers over northern portions of the forecast area, as the cooler air is reinforced. && .LONG TERM /SATURDAY THROUGH TUESDAY/... As of 420 AM Tuesday... Canadian high pressure crosses Saturday, bringing about cool, crisp football weather. Mountain valley frost is possible this weekend, and will continue this mention in the HWO. However, clouds may impede frost formation Saturday morning. Upper level ridging and southerly flow ahead of the next cold front approaching from the west, will bring slightly warmer weather to close out the weekend, and start the new work week, but even then, temperatures will be some 15 to 20 degrees lower than recent days. While there will be some moisture return ahead of the cold front, destabilization is not likely, and rainfall amounts will be light. More cool air arrives behind the cold front for Tuesday. && .AVIATION /18Z TUESDAY THROUGH SUNDAY/... As of 130 PM Tuesday... Widespread VFR conditions through the period. Mostly sunny skies will prevail this afternoon, with some thin cirrus clouds moving north across the area. Diurnal low level cu will also develop from the eastern mountains to central WV through the peak heating hours. Similar conditions expected tonight, with some low stratus redeveloping once again along the eastern slopes, perhaps affecting BKW under sfc south southeast flow. Boundary layer flow greater than 20 knots should prevent widespread fog formation over the most common places overnight. By Wednesday, models show a plume of moisture as seen in an increase in PWATs to around 2 inches, lifting north like a warm front. However, do not see any significant forcing mechanism to produce strong convection. Therefore, only expecting light to moderate rain showers with associated MVFR cloud cover. A strong FROPA to reach southeast OH early Thursday morning, and exit the eastern mountains by 00Z Friday. Expect brief periods of IFR conditinos under showers and storms along the front, a sharp wind shift from the northwest is expected behind the front bringing much cooler temperatures. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z WEDNESDAY... FORECAST CONFIDENCE: High. ALTERNATE SCENARIOS: MVFR stratus affect BKW for a time tonight. 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 EDT 1HRLY 14 15 16 17 18 19 20 21 22 23 00 01 CRW CONSISTENCY H H H H H H H H H H H H HTS CONSISTENCY H H H H H H H H H H H H BKW CONSISTENCY H H H H H H H H H H H H EKN CONSISTENCY H H H H H H H H H H H H PKB CONSISTENCY M H H H H H H H H H H H CKB CONSISTENCY H H H H H H H H H H H H AFTER 18Z WEDNESDAY... IFR along showers or storms possible Wednesday night through Thursday. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...None. OH...None. KY...None. VA...None. && $$ SYNOPSIS...TRM/30 NEAR TERM...ARJ SHORT TERM...TRM LONG TERM...TRM AVIATION...ARJ