Area Forecast Discussion
Issued by NWS Charleston, WV

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693 FXUS61 KRLX 260615 AFDRLX Area Forecast Discussion National Weather Service Charleston WV 215 AM EDT MON SEP 26 2016 .SYNOPSIS...
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High pressure shifts east overnight. A cold front crosses Monday with showers and thunderstorms. Another cold front passes Wednesday / Wednesday night followed by a closed upper level low.
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&& .NEAR TERM /THROUGH MONDAY/...
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As of 215 AM Monday... Forecast on track other then raising overnight dew points to account for evening recovery. As of 8 PM Sunday... Not much change for the front tomorrow, but did tweak dew points and RH to better match obs which the HRRR picked up on. As of 230 PM Sunday... Models are in good agreement with a cold front moving rapidly eastward across the area Monday. The front will reach the Ohio River by early afternoon and in the mountains by evening. Even with the speed of the system, models have a combination of decent dynamics and pooling of moisture to near 2 inches along the front. Thus, a band of showers and thunderstorms is expected to accompany the front. However, QPF amounts will only be on the order of a quarter to half an inch, thanks to the speed of the system. SPC continues to outline a marginal risk of severe weather, and will continue this in the Hazardous weather product. Models also have a prefrontal band of convection forming Monday afternoon along and east of the I79 corridor. Not too certain about an organized area of convection there, so will go with scattered convection there in the moist and unstable air; ahead of the frontal band of convection. Convection will then ramp down fairly quickly in the west behind the front by end of period...with even some sunshine by later afternoon. Milder tonight with increased moisture and southerly winds picking up late, especially in the west. Highs Monday will still reach into the 80s ahead of the front.
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&& .SHORT TERM /TONIGHT THROUGH WEDNESDAY/... As of 315 PM Sunday... Continuing from the near term forecast, the cold front should move quickly through the mountains, and take the trailing POPS with it. Closed low drops south through the Great Lakes...with a lobe in the cyclonic flow and a cold front developing along the Ohio Valley. The bulk of the frontogenesis will exist in the southeastern half of the CWA ahead of the upper level lobe, keeping these two forcing features separate as they arrive Wednesday. Dropping low level temperatures and 1000-500mb thicknesses signify a wholesale airmass change with the broad closed low over the area. && .LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/... As of 315 PM Sunday... Operational GFS, in a bit of a surprise, has now trended towards the operational ECMWF with the closed low aloft oscillating around over the eastern CONUS. Ensemble members still lean towards an quicker exiting open wave aloft...but the GFS ensemble mean changes from 00Z to 12Z look to be coming more in line with the aforementioned operational long term models. From a sensible weather standpoint, this typically results in a more off than on precipitation scheme and a temperature forecast that can end up cooler than the guidance numbers suggest. For the time of year, nothing seems out of the ordinary in the forecast based on seasonal norms, however. && .AVIATION /06Z MONDAY THROUGH FRIDAY/...
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As of 215 AM Monday... MVFR valley fog is likely to form east of the Ohio river overnight. Low stratus in the Greenbrier Valley approaches or overtakes BKW. All of this mixes out after 13Z Monday. A cold front coming from the west will bring a thin line of showers and thunderstorms across the area Monday afternoon. Timing is 18-20Z along the Ohio River, 20-23Z CKB to CRW, and 21-00Z in the mountains. The front will cross near the end of the above mentioned time ranges. A brief period of stratus and fog is likely to follow the cold front Monday night. Light southeast surface flow overnight will become gusty southwest ahead of the cold front Monday, with stronger gusts possible in thunderstorms. The wind will shift to west to northwest behind the front, and be briefly gusty before diminishing Monday night. Light southwest flow aloft will become moderate southwest ahead of the front Monday afternoon, and then light to moderate west to northwest behind the front Monday night. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z TUESDAY... FORECAST CONFIDENCE: Medium. ALTERNATE SCENARIOS: MVFR valley fog may not happen, or it may happen faster or even briefly go IFR overnight. Stratus may not make it into BKW overnight, or may take longer to move back out on Monday. The timing and impact of showers and thunderstorms with the front Monday afternoon and early evening may vary. Stratus and fog behind the front Monday night may vary. 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 MON 09/26/16 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 M M M M M H H H H HTS CONSISTENCY H H H H H H H H H H H H BKW CONSISTENCY M M M M M M M H H H H H EKN CONSISTENCY M M M M M M M M H H H H PKB CONSISTENCY H H H H H H H H H H H H CKB CONSISTENCY H H H H M M M M H H H H AFTER 06Z TUESDAY... Morning valley fog possible Tuesday through Friday mornings.
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&& .RLX WATCHES/WARNINGS/ADVISORIES... WV...None. OH...None. KY...None. VA...None. && $$ SYNOPSIS...JMV NEAR TERM...TRM/JMV/JW SHORT TERM...26 LONG TERM...26 AVIATION...TRM

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