Area Forecast Discussion
Issued by NWS Charleston, WV

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000 FXUS61 KRLX 230732 AFDRLX Area Forecast Discussion National Weather Service Charleston WV 332 AM EDT Mon Oct 23 2017 .SYNOPSIS... Strong cold front and low pressure system cross today and tonight. Much cooler weather by midweek. Another cold front next weekend. && .NEAR TERM /THROUGH TONIGHT/... As of 150 AM Monday... A strengthening low pressure system will lift through KY/IN and into MI today. This will push a strong cold front through the Ohio River Valley and Central Appalachians this afternoon into tonight. Models also showing a wave of low pressure along the front lifting up the spine of the Appalachians this evening. Southeast winds already picking up ahead of the front and have gone with a non-diurnal temperature trend for the rest of the early morning. A stout low level jet in place today -- with 850mb winds increasing to 50-60kts. This will translate to gusty winds at the surface. A blend of hi-res models yielded gusts of 25-35 kts ahead of the cold front. Gusts along the highest peaks could even be a bit stronger. Precipitation will be on the increase as moisture pumps into the forecast area today. Models trying to show showers by 12Z, but think it will take a bit longer to saturate the low levels so waited until after 12Z to really get things rolling. Heaviest rain will be with the cold front late this afternoon into this evening. Did not include any mention of thunder, due to little to no instability. However, cannot rule out a stray dynamics driven rumble. Even without the instability/thunder, stronger showers could mix down stronger winds capable of damaging weak trees. PWAT values top out in the 1.5-1.75 inch range late today. A band of heavy rain is expected near the front. The ground is generally pretty dry and the entire system will be moving nicely, so not anticipating any widespread or significant water issues. But heaviest rain could still lead to some local ponding. Cold front departs to the NE overnight, with POPs decreasing. Kept some 20 POPs going, however it looks like we should have a decent dry period overnight with a dry slot rotating through. && .SHORT TERM /TUESDAY THROUGH WEDNESDAY/...
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As of 230 AM Monday... Models indicate a deep low pressure system over the Great Lakes region with a cold front extending south, well east of our eastern mountains Tuesday. An upper level trough will cross Tuesday and Wednesday. This trough will provide some moisture and lift, allowing for a chance of showers. With colder air aloft, could see some snow flakes in the higher elevations of the northern WV mountains. By Tuesday night, models show H850 temperatures reach minus 2-3C, suggesting a widespread area with surface temperatures at or below 36 degrees over the lowlands. This poses a threat for a widespread frost event Tuesday night into Wednesday morning. Mainly dry Wednesday.
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As of 230 AM Monday... A high pressure system will build over the area, to provide dry weather conditions Thursday and Friday. Strong cold front will move into the area from the west over the weekend. There are minor differences in the arrival timing among the GFS and ECMWF models. This looks like a progressive system, so rainfall accumulations, although heavy at times, could be minor.
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&& .AVIATION /06Z MONDAY THROUGH FRIDAY/... As of 150 AM Monday... Busy forecast period as a strong cold front crosses late today. Ahead of the front, will have clouds and precipitation on the increase driven by strong southeasterly flow. Winds at 850mb will be increasing to 50-60kts by this afternoon, and have included gusty conditions in each TAF. Strongest surface winds will be at higher elevation terminals. Have included a period of 2-3 hours of IFR visibilities in showers just along and ahead of the cold front. In reality the window of IFR will not be that long, so hopefully can tighten up the timing as we get closer. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z TUESDAY... FORECAST CONFIDENCE: Medium. ALTERNATE SCENARIOS: Timing of showers may vary by an hour or two. 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 10/23/17 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 H H H H H H M HTS CONSISTENCY H H H H H H H H H M M L BKW CONSISTENCY H H H H H H H H H M M L EKN CONSISTENCY H H H H H H H H H H H M PKB CONSISTENCY H H H H H H H H H H H M CKB CONSISTENCY H H H H H H H H H H H M AFTER 06Z TUESDAY... River valley IFR fog possible early Tuesday morning. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...None. OH...None. KY...None. VA...None. && $$ SYNOPSIS...ARJ/MZ NEAR TERM...MZ SHORT TERM...ARJ LONG TERM...ARJ AVIATION...MZ is the U.S. government's official web portal to all federal, state and local government web resources and services.