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
879 FXUS61 KRLX 190753 AFDRLX AREA FORECAST DISCUSSION National Weather Service Charleston WV 353 AM EDT Thu Sep 19 2024 .SYNOPSIS... Low pressure system exits northeast tonight, allowing a few rain showers or storms to develop this afternoon. Dry and mostly quiet weather returns Friday through the weekend. && .NEAR TERM /THROUGH TONIGHT/... As of 200 AM Thursday Weak surface high pressure shifting toward the area from the north will not be enough to hold off any chances for shower and/or thunderstorm activity this afternoon. Around 2000 J/kg of CAPE will support a few thunderstorms just as yesterday, however the potential should only be confined to mainly the higher elevations, but we cannot rule out a few rogue showers/storms across the lowlands mainly along the Ohio River and east of there. Once the afternoon Cu field scatters out by late afternoon chances of any activity will diminish along with most cloud coverage for the early evening as upper level ridging moves in from the west. A quiet night will follow with very weak surface flow and mostly clear skies which will cause for another potential day for dense fog, especially across the mountain valleys. With plenty of breaks in cloud coverage today temperatures will be allowed to climb to above seasonable, sort of like yesterday, but not expecting anywhere to reach above the 80`s with the mountains staying in the 70`s and 60`s for the peaks and ridges. && .SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/... As of 350 AM Thursday... Friday may start with dense morning fog, but not a lot of shallow moisture, so low stratus will not be very prevalent nor persistent. A small mid/upper-level short wave ridge over the middle Ohio Valley brings mainly dry weather on Friday. Models do show sufficient low level /h85/ moisture to, together with diurnal heating, provide enough destabilization for the pop up afternoon shower or thunderstorm, at least in the mountains. The forecast continues to trend muddier for the start of the weekend. A developing gradient with high pressure anchored down the east side of the Appalachians, and weak low pressure approaching from the west, sets up southerly low level weak warm advection flow. With several mid/upper-level short wave troughs riding over top of the ridge, and coming down its east side, at least patchy cloud is likely, and central guidance reflects a chance for at least diurnal showers and thunderstorms. Temperatures will remain above normal, with lowland highs up around 90. RH percentages will drop into the 30s across much of the area Friday afternoon, with a few 20s even possible. RH percentages are now forecast to be in the 30s and 40s on Saturday. && .LONG TERM /SUNDAY THROUGH WEDNESDAY/... As of 350 AM Thursday... Brief, weak surface high pressure, together with a small mid/upper-level short wave ridge, should keep Sunday mainly dry. The ridge continues moving east Sunday night and Monday, opening the door for more short wave energy to arrive from the west. Southerly warm, moist advection low level flow reestablishes, and showers and thunderstorms are possible starting overnight Sunday night. The chance for showers, and mainly diurnal thunderstorms, then continues until there is enough short wave amplification in the east to drive a surface cold front through, probably around midweek next week. After another hot afternoon on Sunday, high temperatures gradually settle back toward normal amid the unsettled weather during the next work week, while lows remain above normal. && .AVIATION /07Z THURSDAY THROUGH MONDAY/... As of 130 AM Thursday... Models have hit hard on dense fog this morning covering most of the area. After full analysis went ahead and elected to add fog into all the sites except for BKW who will likely endure a low MVFR deck into the afternoon, therefore deterring fog formation. The other sites may not be so lucky as mostly clear skies and calm wind will allow for some patchy fog to develop which may become dense at times. Any fog will lift and scatter out by 13-14Z. An afternoon Cu deck may develop today but will likely scatter out quickly by the late afternoon becoming mostly clear by the evening. High pressure builds in from the north but there will remain some chances for showers and/or thunderstorms mainly along the mountains possibly affecting BKW/EKN during the mid afternoon, but the threat will quickly diminish by the late afternoon. Any IFR/MVFR CIGs will lift and scatter out by 14-17Z. For the overnight, expect potential for more dense fog as the same conditions will be in place, especially across the mountain (eastern) sites. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z FRIDAY... FORECAST CONFIDENCE: Low into early morning. High today. ALTERNATE SCENARIOS: Low stratus and/or dense fog formation may vary from forecast overnight. 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 09/19/24 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 M L L M M M M L H H H H HTS CONSISTENCY H H L M M M M M H H H H BKW CONSISTENCY M L L M M M M M M M M M EKN CONSISTENCY M M M M M M M L M H H H PKB CONSISTENCY H H L L L M L L M H H H CKB CONSISTENCY M M L M L L M H H H H M AFTER 06Z FRIDAY... IFR possible in low stratus or fog Friday morning. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...None. OH...None. KY...None. VA...None. && $$ SYNOPSIS...TRM/JZ NEAR TERM...JZ SHORT TERM...TRM LONG TERM...TRM AVIATION...JZ