984 FXUS61 KRNK 161348 AFDRNK Area Forecast Discussion National Weather Service Blacksburg VA 948 AM EDT Thu May 16 2024 .SYNOPSIS... A wavy boundary and lingering moisture will keep isolated showers and thunderstorms in the forecast today before ending this evening. Another storm system will cross the area Saturday through late Sunday. This system will bring widespread rain to the area. Monday and Tuesday look drier. High temperatures generally look to be in the 60s and 70s, with a slight cool off beginning Sunday. && .NEAR TERM /THROUGH TONIGHT/... As of 945 AM EDT Thursday... Fog has diminished, but still have low clouds hanging around this morning. Should see clouds thin a bit as the day goes, but will not be a totally sunny day. Overall still expecting a mostly dry day, but a few afternoon showers and perhaps an isolated thunderstorm will be possible. Any rain/storms will be weakening by sunset. As of 230 AM EDT Thursday... Key Messages: 1) Isolated showers this morning with lingering cloud cover today...some clearing. 2. Chances for showers/isolated storms return briefly this afternoon, and end after dark. A trough of upper level low pressure and associated PVA will continue to move off the East Coast this morning. A weak surface trough was helping to keep a few areas of light rain over parts of the Piedmont this morning. Elsewhere, stratus and fog as well as a little drizzle were noted. Stratus and fog will gradually lift later this morning, with some clouds, especially over the mountains, hanging around a good portion of the day. A wavy boundary approaching from the north and breaks in cloud cover will keep a chance for showers and thunderstorms in the forecast for this afternoon and evening, with the higher chances over the mountains. East of the Blue Ridge will have less of a chance due to weak NW flow, but we may see some spillover. This activity will end after dark. Instability will again be very limited so not expecting anything strong...however moderate rain is possible. Highs today will be limited by clouds, but rising heights and breaks in cloud cover should get us into the mid 60s to mid 70s for the mountains, and the mid 70s to near 80 for the Piedmont. Tonight into Friday morning, expect more fog, some of it dense, with lows in the 50s. Confidence in the near term forecast is high. && .SHORT TERM /FRIDAY THROUGH SUNDAY NIGHT/... As of 200 AM EDT Thursday... Key Messages: 1. Rain and thunderstorms late Friday and through the weekend. 2. Near normal temperatures, cooler over the weekend. Friday will start off dry, with weak ridging aloft over the southeast and high pressure overhead. An upper trough will slowly track eastward from the central US into the Ohio and Tennessee Valleys through the end of the work week, while a low pressure deepens over the Gulf Coast states. South to southeasterly flow at the surface behind a lifting warm front, and southwesterly flow aloft ahead of the approaching trough will advect warmer air and more moisture into the area, PWATs forecast to reach 1.25" to 1.5", which is above the 90th percentile relative to climatology, by late Friday. With ample moisture in the atmosphere, there is the potential for heavy rainfall Friday through Saturday, which raises some concerns for localized flooding of urban areas and areas that have recent rainfall already this week. The marginal risk of excessive rainfall is mainly for the west on Friday, where the rain will reach first, before expanding to the rest of the forecast area for Saturday, as coverage of showers and possible storms becomes more widespread. Storm potential Friday will depend on how much surface heating the area will receive through the day. Forecast SBCAPE values are around 1000 J/kg by Friday afternoon, so enough to get some scattered storms to develop, and with forecast shear between 30 to 40 knots, some multicell storms are possible. Saturday will be similar, although showers through most of the day, and with the upper trough just to the west of the area, may see more widespread coverage of showers and storms. Coverage should start to wane after Sunday morning, as the upper wave passes the area, and surface low moves off the coast, though there is not much agreement among models as to when the low finally departs. Temperatures will be warmest on Friday, especially if there are more breaks in the clouds. Saturday will be cooler with clouds and rain, and Sunday looks be cooler as well, with winds turning northeasterly, but also depending on when showers move out of the area. && .LONG TERM /MONDAY THROUGH WEDNESDAY/... As of 230 AM EDT Thursday... Key Messages: 1. Drier weather for first half of the week. 2. Warming temperatures, reaching above normal by midweek. Following the weekend system, 500mb ridging starts to move back into the area, and high pressure centered over the northeast will wedge down the east side of the mountains. That being said, the area may be cooler and hold on to clouds longer on Monday than current guidance suggests, especially if there is still ample moisture present, with the low sitting just off the VA/NC coast. With models trending a bit slower with the passage of the upper trough and surface low, still somewhat uncertain in how long any rain showers will linger in the area, though confidence is increasing that late Monday and Tuesday should be drier as ridging builds overhead. A broad 500mb trough will track eastward through the central US through the midweek and will help to flatten the upper ridge over the eastern US. The associated cold front looks to reach the Midwest and Ohio Valley by Wednesday. Although towards the end of the forecast period, with warming temperatures and increasing dewpoints ahead of the front, will have to watch for any storm potential. Temperatures will be on a gradual warming trend through the period, reaching near to just above normal by midweek. && .AVIATION /14Z THURSDAY THROUGH MONDAY/... As of 240 AM EDT Thursday... A wavy boundary and lingering moisture will keep isolated showers and thunderstorms in the forecast today before ending this evening. IFR conditions will burn off/lift during the 14Z to 18Z time frame, resulting in mostly overcast VFR conditions by early afternoon. May see a few showers and storms develop with late afternoon heating and a boundary nearing from the north. SHRA/TSRA looks scattered again, but more likely for the mountain terminals. Late tonight into Friday morning expect another round of IFR to MVFR fog and stratus. EXTENDED AVIATION OUTLOOK... Friday: Deteriorating conditions. Flight restrictions possible by afternoon due to low CIGs with an increasing coverage of SHRA/TSRA. Friday night and Saturday: Flight restrictions expected due to low CIGs/VSBYs in SHRA/TSRA. Sunday: Some restrictions possible, especially early, with a decreasing coverage of SHRA/TSRA. Monday: Mainly dry. Isolated SHRA/TSRA possible over the mountains. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...None. NC...None. WV...None. && $$ SYNOPSIS...SH NEAR TERM...BMG/SH SHORT TERM...AS LONG TERM...AS AVIATION...SH