Area Forecast Discussion
Issued by NWS Charleston, WV

Home |  Current Version |  Previous Version |  Text Only |  Print | Product List |  Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
-- Highlight Changed Discussion --
-- Discussion containing changed information from previous version are highlighted. --
254 FXUS61 KRLX 181824 AFDRLX AREA FORECAST DISCUSSION National Weather Service Charleston WV 224 PM EDT Sat May 18 2024 .SYNOPSIS... Mainly diurnal showers and thunderstorms this weekend could cause localized high water, mainly this afternoon and evening. High pressure surface and aloft builds through Tuesday. && .NEAR TERM /THROUGH SUNDAY/... As of 220 PM Saturday... A mid-upper level short wave trough nearby this afternoon drifts east of the area tonight, giving way to building mid-upper level ridging on Sunday. With the elevated heat source effect, convection this afternoon will be most likely in and near the mountains, nearer the short wave. With surface dew points in the lower 60s F and h85 dew points in the lower 10s C contributing to PW values of around 1.25 inches, any thunderstorm this afternoon could be heavy and slow moving if it could remain standing amid the light flow. As the short wave slowly drifts away, and the sun sets, convection will die down, lastly in southeast portions of the area this evening, as a weak mid-upper level low center in the trough axis scoots by just to the south of the forecast area. Areas of dense fog are likely to form again tonight. With moisture more shallow compared with last night and this morning, expect the fog to be more confined to the valleys, but also most likely where ever showers or thunderstorms occur this afternoon. With the more shallow moist layer, any fog is likely to lift and mix out quicker than was the case today. With building mid-upper level ridging and drying Sunday, PW values drop to just under an inch, and afternoon convection will be less prevalent than today, and confined to the mountains. Central guidance temperatures reflect an above normal regime by just a few degrees today, and a few more degrees tacked on for Sunday, with lows tonight also above normal. Valleys tonight will be a bit cooler than hill and ridgetops. Surface dew points remain just below uncomfortable levels for most. && .SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY NIGHT/...
-- Changed Discussion --
As of 233 PM Saturday... A few showers or storms, mainly across the higher terrain from peak heating, should slowly dissipate Sunday evening. Drier, and increasingly warmer weather is in store for Monday into Tuesday, as high pressure surface and aloft builds into the region. Can`t completely rule out an isolated shower or storm developing during peak heating hours either of these days, provided something can break through the cap, but overall, expect much of the period and area to remain dry. With the building ridge across the area, some locations could even top out around 90 by Tuesday, which according to the nws heat risk map, sensitive individuals could be affected, even though this is below criteria for an advisory.
-- End Changed Discussion --
&& .LONG TERM /WEDNESDAY THROUGH FRIDAY/... As of 1200 PM Saturday... Low pressure will move northeast into Canada in the middle of next week, eventually sweeping a cold front across the area on Thursday, although there is uncertainty in its timing and how far southward the front will move through our area. There could be a strong storm Wednesday or Thursday during this period, with better chances at this point looking to be to our west, but confidence in this is low at this point due to uncertainty. Another wave looks to move into the area for the end of the period. && .AVIATION /19Z SATURDAY THROUGH THURSDAY/...
-- Changed Discussion --
As of 220 PM Saturday... Morning MVFR stratocumulus had lifted all but opposite ends of th forecast area, PKB and BKW. It should lift above 3 kft at PKB in the first hour or two of the forecast but ceilings at BKW may stay close to 3 kft this afternoon. Diurnal convection this afternoon will be most prevalent in and near the mountains. Any thunderstorm can produce MVFR to LIFR conditions and gusty winds. Any convection will die down around sunset, but dense fog is likely to form again overnight. The fog forecast may need to be adjusted to account for which TAF sites get rain from a shower or thunderstorm, but some fog or mist is still likely even in the absence of rain this afternoon and evening at a particular location. The fog will lift into IFR stratus and then MVFR stratocu again Sunday morning, but this process will likely be faster than was the case today. A VFR day will then ensue, with less afternoon convection to follow, compared with today. Light north to variable surface flow this afternoon will become calm tonight, and then light and variable on Sunday, all beneath light north flow aloft. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z SUNDAY... FORECAST CONFIDENCE: Medium ALTERNATE SCENARIOS: Timing and intensity of showers and thunderstorms this af could vary. Timing and intensity of fog formation overnight tonight, and lifting of fog Sunday morning, could 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. 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 M L HTS CONSISTENCY M H H H H H H H H H H H BKW CONSISTENCY M M H M H H H H H H H H EKN CONSISTENCY M H H H H H H H H M L L PKB CONSISTENCY M M H H H H H H H H H H CKB CONSISTENCY H H H H H H H H H H M H AFTER 18Z SUNDAY... IFR possible in rain showers and thunderstorms Sunday afternoon in the mountains. IFR in fog possible overnight Sunday night into early Monday morning.
-- End Changed Discussion --