Area Forecast Discussion
Issued by NWS Blacksburg, VA
Issued by NWS Blacksburg, VA
793 FXUS61 KRNK 072316 AFDRNK Area Forecast Discussion National Weather Service Blacksburg VA 716 PM EDT Mon Jul 7 2025 .SYNOPSIS... A warm moist airmass will allow for daily shower and thunderstorm chances. An approaching front from the northwest looks to stall near the area Tuesday onward which may allow for increased coverage of showers and thunderstorms. && .NEAR TERM /THROUGH TUESDAY/... As of 715 PM EDT Monday... No major changes were made to the forecast this evening as isolated showers and thunderstorms linger across the area. A few of these storms may produce gusty winds and frequent lighting. These showers and thunderstorms should diminish over the next few hours as daytime heating comes to an end. Previous Discussion: Key Messages: 1) Isolated showers and storms this afternoon with increasing chances for Tuesday. 2) Heat indices could flirt with advisory levels for east Piedmont Tuesday. As the remnants of tropical cyclone Chantal push east of the area near Delmarva, we should see a pocket of decreased deep layer moisture but still enough surface based instability (generally 1500- 2500 J/kg) to allow for some convective triggering this afternoon. CAMs are in pretty good agreement for coverage to remain pretty isolated but with PWATs remaining high there could still be a localized flooding threat from hydrometeor loading in cell downdrafts. The far southeastern CWA received some high rainfall amounts with the Chantal system last night so such antecedent conditions would make the area more flood prone specifically in the Caswell, SE Pittsylvania and southern Halifax county area. A slow moving frontal boundary and enhanced moisture axis looks to approach the area from the NW Tuesday. This and any impulses traversing along the broad SW flow aloft could allow for more widespread shower and storm development with diurnal heating. This sets up almost cookie cutter daily development for the week with little to no change in the airmass as it stalls or has slight meandering. Temps remain pretty warm with afternoon highs mainly in the low to mid 90s for the Piedmont and mid to upper 80s for parts of the mountains. The humid environment looks to result in heat indices reaching above 100 in parts of the Piedmont Tuesday and may even have some spotty locations near the 105 degree mark so a future issuance of a heat advisory may be warranted mainly in the eastern Piedmont but holding off for now. && .SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY NIGHT/... Key Message: 1)Daily thunderstorms and showers for the rest of the week. Confidence is growing for an active weather week filled with showers and thunderstorms. A frontal system from the northwest will stall over the Ohio River Valley for the foreseeable future, keeping the warm and moist air mass over the Mid-Atlantic in place. A ridge over the Deep South will begin to erode while a stronger ridge over the Southwestern United States will slowly move westward towards California as the week progresses. A trough that is in between these two ridges will transport several shortwaves of various strengths to the area to bring several chances of showers and thunderstorms. Due to the forecast of both ridges, the trough will begin to deteriorate late in the week. Upper level winds will still be relatively zonal to continue support for shortwave and storm system transit through the Mid-Atlantic. There are two concerns regarding these storm systems: severe weather and flooding. Severe weather looks to be on the lower end with only a Marginal Risk for the area on Wednesday due to a presence of 20-30 kt shear. Plenty of CAPE each day (1000-2000 J/kg) will support scattered pulse storms, but the shear may permit a little more organization with some of these storms. Similar CAPE/shear conditions may return on Thursday, so it would not surprise me if at least another Marginal Risk was issued for Thursday by tomorrow. A relatively greater concern is the potential for flooding. Many counties towards the southeast got a good soak from Tropical Depression Chantal and repeated days of precipitation could lead to eventual flooding later this week. PWATs are forecast to be between 1.5-2.0 inches which is a lot higher than the climatological average of around 1.25 inches. The Weather Prediction Center has a Marginal Risk of Excessive Rainfall every day this week for most of the region. Pulse storms would mean very narrow and specific areas would be impacted so it is difficult to know with confidence at this point what counties or cities would be more at risk. && .LONG TERM /FRIDAY THROUGH MONDAY/... Key Message: 1) Daily showers and thunderstorms continue into the foreseeable future. The weather pattern of daily showers and thunderstorms continues into early next week. With no fronts expected to pass through, there is nothing to move the warm and moist air mass away from the region. CAPE is plenty and PWATs are forecast to stay high but with little flow and shear, most of these storms are expected to be pulse based and produce heavy rainfall. The flood risk may extend for additional days because of this. The upper level ridge over the southwestern CONUS is expected to still exist and keep its strength though it may migrate a little more to the California Coast. Another ridge over the Deep South may redevelop and spatially stretch across most of the southern United States. This ridge may increase northward towards the end of the forecast period, but until it does this most of the overall upper level flow will maintain the train of shortwaves and storm systems through the Mid-Atlantic. && .AVIATION /23Z MONDAY THROUGH SATURDAY/... As of 645 PM EDT Monday... Mainly VFR conditions are expected through the period outside of early morning valley fog at LWB that may lead to a few hours of MVFR to LIFR restrictions between 0900 to 1200 UTC Tuesday morning. Additional rounds of scattered to widespread showers and thunderstorms is expected on Tuesday as a frontal boundary approaches the region. Winds across the area will remain light out of the southwest at around 5 to 7 knots across the area during the TAF period. Outside of any brief periods of restrictions in and around the aforementioned showers and thunderstorms, predominantly VFR conditions are expected for all terminals. .EXTENDED AVIATION OUTLOOK... The forecast area then transitions back into a typical summertime weather pattern with daily chance of showers/storms during the peak heating hours each day through the end of the work week. Morning fog will also be possible each day, especially at LWB and BCB. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...None. NC...None. WV...None. && $$ SYNOPSIS...SH NEAR TERM...AB/EB SHORT TERM...CG LONG TERM...CG AVIATION...AB/EB