Area Forecast Discussion
Issued by NWS Blacksburg, VA
Issued by NWS Blacksburg, VA
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
466 FXUS61 KRNK 121748 AFDRNK Area Forecast Discussion National Weather Service Blacksburg VA 148 PM EDT Sun May 12 2024 .SYNOPSIS... High pressure bringing dry weather to the region through Monday afternoon will move off the atlantic coast by Monday evening allowing moisture to return in advance of a complex storm system exiting the central plains. This will result in unsettled weather Monday night through Wednesday with periods of showers and a few thunderstorms. Drier weather returns Thursday before another storm system brings the threat for showers and storms by Friday. && .NEAR TERM /THROUGH MONDAY/... As of 140 PM EDT Sunday... Key Message: 1. Slowed the arrival of showers in northwest NC Monday afternoon. As the upper level trof extending from New England south to the eastern Mid Atlantic region pushes east, high pressure aloft and at the surface will build over the region tonight allowing gusty afternoon winds to diminish around sunset. Confidence is lower than normal for low temperatures tonight, as high cloudiness across the south central in southeast U.S. along an active southern jetstream will spill over the area late tonight and early Monday morning. With dry air and diminishing winds this evening, temperatures should fall rapidly early tonight, but will likely slow a few hours before dawn Monday. Generally leaned toward the cooler guidance for lows considering the magnitude of dry air in place. There is generally good agreement in ensembles and CAMs that weak upper level shortwave energy undercuts the departing upper level ridge keeping mostly cloudy skies in place, but with increasing 1000-850mb thicknesses and breaks in the cloud cover temperatures should still be able to warm a few degrees above Sunday`s high temperatures. Where confidence is lowest in tomorrow`s forecast is the timing of light showers in northwest NC for late tomorrow afternoon or tomorrow evening, with the SREF plumes showing a larger than normal spread of POPs/dew points Monday afternoon/evening. CAMs also show a wide range of outcomes for when precipitation arrives. A majority of the SREF ensemble members in BUFKIT retain a healthy amount of low level dry air into the afternoon on Monday, so leaned toward the slower arrival time of precip and reduced POPs across the NW NC mountains Monday afternoon. && .SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY NIGHT/... As of 120 PM EDT Sunday... Key Message: 1) Confidence is high for unsettled weather during Tuesday and Wednesday with showers and thunderstorms. Clouds will increase on Monday night as a low pressure system approaches the central Mississippi River Valley. Showers will reach the southern Blue Ridge and far southwest Virginia overnight and spread across the rest of the Mid Atlantic on Tuesday. Instability will increase from the west to spark thunderstorms in the mountains by Tuesday afternoon. The low pressure system will cross over the Appalachian Mountains on Wednesday to keep conditions unsettled with more showers and thunderstorms. Some drier air may arrive by Wednesday night to provide lower chances of rain. && .LONG TERM /THURSDAY THROUGH SUNDAY/... As of 120 PM EDT Sunday... Key Messages: 1) Confidence is moderate for a brief reprieve on Thursday, but more showers and thunderstorms are possible to end the week. With a low pressure system moving offshore on Thursday, chances of rain will become more limited. However, another low pressure system should approach the Ohio River Valley by Friday. Although the models continue to struggle with timing discrepancies for this next system, it appears that the chance of showers and thunderstorms will rise again by Friday and linger into Saturday. Drier air may return by Sunday to allow the rain chances to decrease. Overall, temperatures throughout this forecast period will stay near or slightly above normal for the middle of May. && .AVIATION /18Z SUNDAY THROUGH FRIDAY/... As of 105 PM EDT Sunday... Early this afternoon, VFR conditions were reported at all TAF sites and confidence is high that VFR conditions will persist through the TAF period. While there is a small chance (less than 20%) that a brief period of MVFR or IFR conditions due to localized fog will occur at KLWB early Monday morning, confidence was too low to include it in the TAF. Winds gusting to 15 to 25 knots during the afternoon will subside around sunset and become light and variable tonight. As High pressure drifts to the east of our area Monday, winds will become south at less than 10 knots. High level clouds will overspread the region during the pre-dawn hours Monday and persist into Monday afternoon, but confidence is high VFR ceilings will prevail through 18Z Monday. Extended Aviation Outlook... Precipitation and sub-VFR ceilings and visibilities return to the region as Monday night through midweek. Thursday should return to VFR most areas with some lingering MVFR possible in the mountains. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...None. NC...None. WV...None. && $$ SYNOPSIS...PH NEAR TERM...PH SHORT TERM...PW LONG TERM...PW AVIATION...PH