Area Forecast Discussion
Issued by NWS Blacksburg, VA
Issued by NWS Blacksburg, VA
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076 FXUS61 KRNK 260711 AFDRNK Area Forecast Discussion National Weather Service Blacksburg VA 311 AM EDT Sun May 26 2024 .SYNOPSIS... A series of disturbances will pass across the lower Mid-Atlantic through Monday, triggering rounds of shower and thunderstorm activity ahead of an approaching cold front. The front will pass across the central Appalachians Monday evening, ushering in drier and slightly cooler weather for much of the coming week. && .NEAR TERM /THROUGH TONIGHT/... As of 240 AM EDT Sunday... Key Messages: 1. Mostly sunny and warm today, so keep plenty of cool non- alcoholic beverages and sunscreen handy if remaining outdoors for extended periods of time. 2. A line of showers and thunderstorms will arrive from the west this evening, a few of which are likely to become severe. 3. Another line of showers and thunderstorms may arrive early on Memorial Day, though timing and intensity are less certain. Starting the morning off with mostly clear skies and light winds, making for the perfect setup for the development of patchy fog. IR satellite imagery already depicts fog filling in the mountain river valleys, a trend that will continue over the next few hours. With mostly clear skies in place after sunrise, temperatures will spike upward, allowing fog to burn off quickly after 8 am. Temperatures will max out in the upper 70s to the mid 80s by mid-afternoon. Will be keeping an eye on the potential for a line of showers and thunderstorms arriving from the west and reaching the Interstate 77 corridor during the 5 pm to 7 pm timeframe. The storms will then race quickly to the east, reaching the Highway 29 corridor in the Piedmont during the 7 pm to 9 pm timeframe. With a day of strong heating expected, believe there will be enough energy in the atmosphere to allow a few storms to intensify to severe levels, more so across the mountains as the storms arrive just after maximum daytime heating. The main threat will be damaging winds, though large hail and even an isolated tornado cannot be ruled out. There is also the chance of heavy downpours that may lead to localized flooding, though these storms will be moving fast enough that prolonged heavy rain will remain a remote possibility. By 10 pm, the severe threat will temporarily diminish as the line passes out of our area to the east, bringing a brief lull in the organized activity, with only residual showers to contend with. However, decent agreement exists in the rapid update weather forecast models that another line of storms will approach from the west during the predawn hours of Monday. Not as confident on the timing of this next round of activity or its intensity given that it would be entering an environment drained of instability by the earlier round of storms. Expect early morning lows to start Memorial Day to range from the low to mid 60s. && .SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/... As of 200 PM EDT Saturday... Key Messages: 1: Front on Monday could bring strong storms 2: Things quiet down Tuesday During the night Sunday and into Monday a strong cold front will continue to raise precip chances, with a maximum on Monday afternoon. Some of the highest instability we`ve seen of late will also be in place over the area on Monday, with models suggesting 1500+ J/kg MLCAPE over most of the CWA. Ensemble guidance also agrees on a high probability of enhanced CAPE. As such Monday is the day we are focusing on for a potential severe weather outbreak. We currently have a slight risk outlook for severe weather. Given the wet antecedent conditions from daily showers and storms since last Thursday, the convective nature of Monday`s storms could also lend itself to flash flooding due to heavy rain. Tuesday will much calmer in the wake of the front, though there could be a few mountain showers due to an embedded shortwave rotating around through the backside of a trough axis. East of the mountains there will be little to no rain. Temperatures will be above normal in the low to mid 80s through Tuesday. && .LONG TERM /WEDNESDAY THROUGH SATURDAY/... As of 230 PM EDT Tuesday... Key Messages: 1: Largely quiet forecast with cooling temperatures After Monday`s frontal passage, we will be positioned on the western side of a mid-level trough, and the eastern side of a surface high. For most of the week, this will force northerly or northwesterly flow, and consequently, cold air advection. Temperatures will be on the decline through Friday, when temps will be around or a few degrees below normal. The mountains will have scattered to broken cloud cover due to the flow, and some isolated diurnal showers could form up Thursday. The surface high will transition to directly overhead the Mid-Atlantic by Friday, shutting off rain chances even further. && .AVIATION /06Z SUNDAY THROUGH THURSDAY/... As of 255 AM EDT Sunday... Patchy fog this morning given mostly clear skies and light winds. Fog particularly thick in the mountain river valleys, including LWB and BCB. Expected to burn off quickly after 26/12Z given sunshine and strong heating. Expect winds from the south today at less than 10kts. VFR conditions expected through most of the day until a line of showers and thunderstorms arrives during late afternoon. This line is expected to move rapidly from west to east, impacting the mountains during the 26/21Z to 27/00Z timeframe, and the Piedmont during the 26/23Z to 27/02Z timeframe. A few storms across the mountains are likely to become severe, producing damaging wind gusts, though large hail and an isolated tornado cannot be ruled out also. Downpours and low ceilings will accompany the storms, but are expected to remain temporary, improving as the convection passes. Lingering debris cloud cover tonight will limit fog formation, though patches of fog may redevelop. Will be keeping an eye on the potential for another line of storms during the predawn hours of Monday, though uncertainty exits in both the timing and intensity of this activity given that it may arrive late at night when instability is diminished. EXTENDED AVIATION OUTLOOK... Periods of showers and thunderstorms will continue through the daytime hours of Monday. MVFR conditions remain likely with any thunderstorms. Thunderstorms developing Monday afternoon have a chance of producing heavy rain, hail, damaging winds, and frequent lightning. A front will cross through the area late Monday into early Tuesday, turning winds to the northwest and eventually bringing drier air to much of the area. A low chance for showers and thunderstorms will be possible across WV Tuesday and Wednesday, otherwise VFR. Patchy fog with periods of MVFR/LIFR will be possible in the mornings near mountain and river valleys. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...None. NC...None. WV...None. && $$ SYNOPSIS...NF NEAR TERM...NF SHORT TERM...VFJ LONG TERM...VFJ AVIATION...BMG/NF