


Area Forecast Discussion
Issued by NWS Blacksburg, VA
Issued by NWS Blacksburg, VA
258 FXUS61 KRNK 132330 AFDRNK Area Forecast Discussion National Weather Service Blacksburg VA 730 PM EDT Sun Jul 13 2025 .SYNOPSIS... Showers and thunderstorms will remain in the forecast each afternoon and evening through the week given warm and moist air situated over the Mid-Atlantic into the Carolinas. A weak cold front will start the week situated near the Ohio River, and push south across the Mid-Atlantic during the middle of the week. Temperatures across the region will be near to slightly above normal for mid-July. && .NEAR TERM /THROUGH MONDAY/... As of 720 PM EDT Sunday... Isolated storms continuing for the next few hours, with isolated strong winds and heavy rainfall the main threats. Gradual decrease after sunset to just a few areas of rain showers and heavier downpours through midnight. Should expect areas of fog again through the early morning hours, especially in locations that received rainfall this evening. Discussion as of 1200 PM EDT Sunday... Key Messages: 1) Isolated severe threat and flash flooding threat mainly for the eastern CWA this afternoon into evening. 2) Monday might be a similar story to today as the airmass and environmental setup should have little to no change. Issued a Flood Watch mainly in line with the Day 1 ERO Slight Risk from WPC through this evening for parts of the eastern CWA in coordination with neighboring offices. Nam Nest CAM has good coverage of convection in line with the area and should be ample CAPE and high PWATs to support not just efficient precip producers for flash flooding threat but also wet microburst/damaging wind potential from hydrometeor loaded downdrafts. Similar eastern part of the area is also in a Day 1 Marginal Risk for severe storms from SPC. Any impulses traversing the broadly SW flow aloft could enhance development and of course outflow boundaries can trigger storms almost anywhere when activity gets going. Monday will not see much change if any to the environmental setup and SPC did end up upgrading a similar area to a Day 2 Marginal severe risk in the latest update. WPC again has part of our area in a Day 2 ERO Slight mainly along and east of the Blue Ridge so all in all it may be a wash, rinse, and repeat day. Overnight low and afternoon high temps should remain above climo norms. Any evening precip could result in morning patchy fog as well. && .SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY NIGHT/... As of 1230 PM EDT Sunday... Key Points: 1. Daily chances of showers/storms. 2. Isolated locally heavy rainfall/flooding possible. 3. Above normal temperatures. A look at the 13 Jul 00Z NCEP Ensemble Mean 500mb Geopotential Heights shows for Monday night a longwave trough pattern centered over Hudson Bay. Shortwave troughs will be moving within the flow regime of this longerwave trough, one centered near the Ontario/Quebec border and one extending from Manitoba southwest to the US Pacific NW. A broad region of high pressure will cover much of CONUS south of roughly 40 N latitude. For Tuesday/Tuesday night, little changes synoptically across North America on the broader scale. However, the shortwaves troughs within the longerwave trough pattern migrate eastward. One reaches the Canadian Maritimes, and another dips south into US Northern Plains States. A third holds fast over the Pacific NW. For Wednesday/Wednesday night, there is a general push south of the longwave trough pattern over Canada to into roughly the northern third of CONUS. The main trough axis is expected to be over the Upper Mississippi Valley by the evening hours. At the surface, a weak frontal boundary will become situated over the region Monday night. This feature will experience little movement and/or wash out through Wednesday. High pressure will remain situated off the US East Coast near 30 N latitude. A look at the 13 Jul 00Z NAEFS Ensemble Situational Awareness data shows 850mb temperatures will range from +19C to +21C across the region. The upper end of this range falls within the 90 to 97.5 percentile of the 30-year CFSR climatology. The above weather patterns offers the following forecast. With a weak boundary arriving, and stalling over the region, daily chances of showers and storms will continue. Most of these will occur during the afternoon and evening hours. However, the presence of the front may help keep the activity lingering longer than sunset. Additionally, with expected relatively weak steering flow, any showers/storms that form will likely be slow moving, and have the potential to produce locally heavy rain in a short period of time. Likewise, multiple showers/storms crossing the same area in a short period of time may also yield locally heavy rain/flooding concerns. Temperatures will continue to be above normal through the period. Confidence in the above weather scenario is high. && .LONG TERM /THURSDAY THROUGH SUNDAY/... As of 1230 PM EDT Sunday... Key Points: 1. Threat of daily showers/storms continues. 2. Isolated locally heavy rain/flooding concern, especially Friday into the weekend. 3. Above normal temperatures. 4. Heat Index values around or slightly over 100F far eastern areas. A look a the 13 Jul 00Z NCEP Ensemble Mean 500mb Geopotential Heights shows for Thursday/Thursday night depicts a longwave trough over much of southern Canada and the northern quarter of CONUS. A broad area of ridging is expected over most of CONUS south of 40 N latitude. The strength of the ridge may increase across the SE US. For Friday/Friday night, not a lot is expected to change on the synoptic scale as compared to Thursday. The main trough axis remains across the Great Lakes region, a shortwave trough is expected to be over British Columbia, and the center of a broad w-e oriented ridge remains over SE US. For Saturday/Saturday night, the trough axis is expected to make progress eastward, reaching the eastern Great Lakes and New England region. In response, the center of the broad ridge shifts west a bit. For Sunday, little change is expected in comparison to Saturday. At the surface, a general area of weak localized low pressure is expected to be across eastern portions of VA/NC/SC through Friday. Heading into the weekend, a cold front will approach the region and stall near the Ohio River Valley and Mason-Dixon Line region. High pressure will be centered off the US East Coast with its ridge axis over the SE US. A look at the 13 Jul 00Z NAEFS Ensemble Situational Awareness data shows 850mb temperatures on Thursday of +19C to +21C, on Friday of +20C to +21C, on Saturday of +19C to +20C, and on Sunday +18C to +19C. The above weather patterns offers the following forecast. The region will continue to be positioned within an airmass conducive the development of primarily diurnal showers and storms, with locally heavy rain a concern. The concern increases for the weekend as a front approaches the regions stalls just to our north. This added feature to the equation may be close enough to promote more than just diurnal coverage. Temperatures will continue to be above normal for this time of year. Additionally, the combination of heat and humidity may result in Heat Index values reaching or going a little above 100F across eastern parts of the forecast area during this time frame, with Friday potentially seeing the highest values of the four days. Confidence in the above weather scenario is moderate to high. The biggest question mark will be position of the advancing front this weekend and its influence on our weather. && .AVIATION /00Z MONDAY THROUGH FRIDAY/... As of 725 PM EDT Sunday... Mainly VFR this evening and into the early overnight hours. Overnight patchy fog could reduce vsbys after midnight and dissipate around daybreak. Expecting similar situation for Monday with shower and storm coverage in the afternoon/evening. Winds overall out of the west to south under 10 kts during the day and light to calm overnight. .EXTENDED AVIATION OUTLOOK... The weather pattern will change little through much of the upcoming week, remaining conducive for isolated to scattered afternoon & evening storms. Higher coverage of storms is forecasted for Tuesday and Wednesday as a weak cold front approaches from the northwest. Outside of storms, expect VFR conditions but with the potential for locally dense fog and MVFR/IFR stratus developing each night, especially for locations that received significant rainfall during the evening prior. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...Flood Watch until 2 AM EDT Monday for VAZ019-020-023-024-034- 035-044>047-058-059. NC...None. WV...None. && $$ SYNOPSIS...NF NEAR TERM...AB/BMG SHORT TERM...DS LONG TERM...DS AVIATION...AB/BMG