Area Forecast Discussion
Issued by NWS Charleston, WV
Issued by NWS Charleston, WV
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
760 FXUS61 KRLX 270232 AFDRLX AREA FORECAST DISCUSSION National Weather Service Charleston WV 1032 PM EDT Wed Jun 26 2024 .SYNOPSIS... A cold front crosses overnight into Thursday, taking its showers and storms with it. Another cold front crosses this weekend, with additional storms. && .NEAR TERM /THROUGH THURSDAY/... As of 1030 PM Wednesday... Severe Thunderstorm Watch 467 was allowed to expire, as the severe weather threat associated with a mid/upper-level short wave trough and surface cold front waned after sunset. The last line of showers and waning thunderstorms was slicing through central WV late this evening, and will push through the rest of the forecast area during the overnight hours, save for light showers or drizzle lingering in and near the mountains into Thursday. As of 830 PM Wednesday... With round two of the severe threat appearing to set up east the Ohio River, have canceled Severe Thunderstorm Watch 467 west of it. Aside from lingering low clouds a little longer and farther west on Thursday, the rest of the forecast remains on track. As of 815 PM Wednesday... The threat for the strongest thunderstorms appeared to be shifting east of the Ohio River. As of 505 PM Wednesday... Severe Thunderstorm Watch 467 in effect until 10 PM to account for ongoing convection in central WV, which has caused tree damage and produced close to one-inch size hail in Kanawha County, and the potential convective development farther west, more closely tied forcing associated with with mid-level short wave trough. As of 1237 PM Wednesday... Showers and storms from this morning will continue to gradually lift north and east of the area. An area of clearing in the cloud cover has occurred across parts of our south and west behind this band, and mesoanalysis and satellite images indicate increasing instability and some cu starting to develop in the area of clearing. Showers and storms will ramp up this afternoon and evening out ahead of a shortwave trough and approaching cold front in the increasingly unstable atmosphere, with the possibility of a few storms becoming strong to severe. Model soundings indicate the potential for 2500 J/Kg cape out ahead of this feature, and with strengthening deep unidirectional shear, linear organization of storms is possible, along with the possibility of pulse severe storms, with a damaging wind threat. In addition, with freezing levels around 12k feet, some marginally severe hail is possible. In addition, with PW values already around 1.7 inches and progged to rise to close to 2 inches, heavy downpours will accompany any storms, and although we are quite dry, a localized water issue cant be completely ruled out in poor drainage/low lying areas. Frontal boundary will clear mountains during the day Thursday. Additional showers and storms will be possible Thursday across the higher terrain from any lingering moisture, but most of the area should dry out and be cooler. && .SHORT TERM /THURSDAY NIGHT THROUGH FRIDAY NIGHT/... As of 215 PM Wednesday... After a comfortable Thursday night with lows ranging from the mid-50s to the mid-60s, winds shift S`ly and bring heat and humidity back to the area for Friday. Highs are forecast in the upper 80s to lower 90s, and dew points creep back up towards 70 degrees. It should remain dry for most of the CWA on Friday, but some convective activity is possible in the higher terrain, especially the southern mountains. A muggy Friday night is in store, with lows generally in the low to mid-70s for lower elevations. Some of the model data hints at a weak upper-level shortwave crossing the area Friday night, which could help enhance shower and t-storm chances area-wide, so POPs were boosted to chance for most of the CWA. && .LONG TERM /SATURDAY THROUGH WEDNESDAY/... As of 225 AM Wednesday... Another shortwave could cross the area during the day Saturday as the next cold front approaches from the west, with showers and storms likely on Saturday. It will also be very humid on Saturday, and likely on the hot side, though that may depend on precip and cloud coverage in the afternoon. SPC did not put any 15% outlook area on the Day 4/Saturday map, as there remains uncertainty on the severe parameters. That said, there is a chance for both sufficient instability and at least marginal shear across the area during the day on Saturday, so we`ll need to monitor for severe potential. Ensemble mean PWATs are near or over 2" for much of the area on all three global ensembles, so flooding risk will also need to be monitored - WPC does have our area in a Marginal excessive rainfall risk for Day 4, which seems sensible at this time. With the front passage currently timed for the late Saturday night or Sunday morning, the severe risk is likely lower than what it would be otherwise. That said, there are some indications in forecast soundings and MU CAPE values that some elevated instability could track with the front, so we may not be able to let our guard down entirely Saturday night. After the wet and muggy start Sunday morning, dry air and surface high pressure working in behind the front will clear the showers and storms, and should drop dew points under 70 degrees for all by sunset. Sunday night through Monday night look to be some banner weather for those looking for a break from the hot weather. Dew points look to be in the 50s to lower 60s, with overnight lows at similar levels and Monday`s highs ranging from upper 60s on the highest ridges to low 80s in the Ohio Valley area. All good things must come to an end, however, and southerly winds developing on Tuesday will bring surging dew points and temperatures across the CWA, though lingering upper- level ridging should hold off rain chances. && .AVIATION /02Z THURSDAY THROUGH MONDAY/... As of 815 PM Wednesday... Showers and thunderstorms becoming more numerous tonight are likely to impact most of not all TAF sites with flight categories at least as low as MVFR at times, with IFR to VLIFR beneath a heavier thunderstorm, along with strong wind gusts. While the threat for the strongest thunderstorms is east of the Ohio River, the showers and thunderstorms in general will move east of the Ohio River altogether by 04Z, CKB and CRW by 06Z and east of the mountains by 07Z. Low clouds and fog will settle in in the wake of the rain and cold front overnight, with MVFR conditions across the middle Ohio Valley and IFR to VLIFR in the mountains. The fog will lift after the dawn, and then the clouds gradually lifting through the morning, yielding VFR conditions for Thursday afternoon as drier air arrives ahead of high pressure to the north. Variable surface flow due to the storms various outflow boundaries associated with them will become light north on Thursday. Light to moderate southwest flow ahead of the front may be just strong enough for LLWS at EKN, before becoming light north to northwest behind the front overnight, and then light north on Thursday. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 00Z FRIDAY... FORECAST CONFIDENCE: Medium ALTERNATE SCENARIOS: Coverage, timing and intensity of showers and thunderstorms tonight may vary from the forecast. Development and duration of low stratus or fog late tonight and early Thursday may vary from 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. DATE THU 06/27/24 UTC 1HRLY 00 01 02 03 04 05 06 07 08 09 10 11 EDT 1HRLY 20 21 22 23 00 01 02 03 04 05 06 07 CRW CONSISTENCY H H M M M M L L L L L L HTS CONSISTENCY H H M H H H H H H H H H BKW CONSISTENCY H H M M H M M H H M H H EKN CONSISTENCY H M L H H H H M M M M L PKB CONSISTENCY H M M L H H H H H L M M CKB CONSISTENCY H M H H H H H H M L L M AFTER 00Z FRIDAY... Brief IFR possible with thunderstorms Saturday and Sunday. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...None. OH...None. KY...None. VA...None. && $$ SYNOPSIS...FK/TRM/SL NEAR TERM...TRM/SL SHORT TERM...FK LONG TERM...FK AVIATION...TRM