


Area Forecast Discussion
Issued by NWS Blacksburg, VA
Issued by NWS Blacksburg, VA
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-- Discussion containing changed information from previous version are highlighted. --478 FXUS61 KRNK 011325 AFDRNK Area Forecast Discussion National Weather Service Blacksburg VA 925 AM EDT Tue Jul 1 2025 .SYNOPSIS... A cold front will move through the region late today, bringing storms capable of producing damaging winds and torrential rain. A slightly cooler and less humid airmass moves into the region by Thursday, with a warm but pleasant holiday weekend in store for most of the area with little to no rainfall expected. By early next week, the typical summertime daily afternoon thunderstorm pattern returns. && .NEAR TERM /THROUGH TONIGHT/...-- Changed Discussion --As of 900 AM EDT Tuesday... Key Message: 1) Numerous to widespread coverage of storms this afternoon and evening. Some will be strong to severe with wind and torrential rains the main threats. Water-vapor imagery this morning indicates an upper trough moving east across the Great Lakes/lower OH Valley. This feature will cross the Appalachians by mid-late evening...preceded by an abundance of moisture and dynamic lift. In the low levels, a cold front analyzed over the southern Great Lakes into the lower OH Valley/Mid South will gradually progress east/southeast crossing our forecast area this evening. Convective allowing models showing storms firing up along the Blue Ridge by noon today, before the pre-frontal, then frontal convection increases coverage through the afternoon/evening. Best shear will stay north of us but dewpoints in the upper 60s to lower 70s combined with the heating from the sunshine and good low level convergence will fuel storms, with damaging winds and potential for excessive rainfall the main threats. Cannot rule out some hail but environment is not as conducive for hail. The front enters the mountains by sunset, then slows as it shifts to piedmont later tonight. Although not everyone will see rain, most will so kept probability`s in the 60 to 90 percent rain. With pwats running 1.75+", storms will be efficient rain producers and storms could train over the same area in waves, so localized flash flooding is not out of the realm. Will have to monitor but given isolated threat will not have a flood watch. There will be some slight hint of airmass change in the mountains by dawn Wednesday but not much, dewpoints dropping into the lower to mid 60s as opposed to upper 60s to lower 70s. Coverage for showers/storms will become more widely scattered late tonight with best coverage with the front in the Piedmont.-- End Changed Discussion --&& .SHORT TERM /WEDNESDAY THROUGH FRIDAY NIGHT/... As of 100 AM EDT Tuesday... Key Points: 1. Continuation of showers/storms on Wednesday, especially in the east. 2. Dry Thursday and Friday. 3. Above normal temperatures all three days. A look at the 30 Jun 12Z NCEP Ensemble Mean 500mb Geopotential Heights shows a shortwave trough situated along the mid-Atlantic east coast of the US Wednesday morning. Another shortwave trough will be on the heels of this first one, positioned over Hudson Bay. A generous area of upper level ridging will extend from the Rockies the Gulf Coast states and across FL. A low/trough combo will extend from the Gulf of Alaska to the Pacific Northwest. On Thursday, the second shortwave trough crosses our region during the morning hours. Ridging continues over the same general as on Wednesday. Likewise, the low/trough combo remains across far western CONUS. For Friday, the trough over the mid-Atlantic area on Thursday is expected to now be centered over the Canadian Maritimes. The ridge axis shifts east the the Mississippi Valley to FL. The far western CONUS trough becomes a little less amplified. At the surface, on Wednesday morning, a cold front will extend from the Canadian Maritimes southwest through New England to over far eastern VA/NC. High pressure will be centered over the mid- Mississippi River Valley, and ridge axis will be positioned west- east over FL. On Thursday, the center of high pressure makes progress eastward, reaching the Lower Ohio Valley by the morning hours. A lee trough is expected to develop over the western High Plains to the western Central Plains states. On Friday, high pressure will be centered over PA/NY during the morning hours with its ridge axis extending to the SE US. To the west, a trough will be located from the Northern Plains States to the Central Plains states. A look at the 30 Jun 12Z NAEFS Ensemble Situational Awareness data shows 850mb temperatures around +17C through the period. The above weather patterns offer the following forecast. With an upper shortwave trough across the area on Wednesday combined with daytime heating, we are expected showers and storms to develop, especially over eastern portions of the region. As the upper shortwave trough exits to the east, the coverage will also decrease from west to east after sunset. For Thursday and Friday, with a building area of high pressure over the region, no showers/storms are forecast. Through the period, temperatures will average three to five degrees above average. Confidence in the above weather scenario is high. && .LONG TERM /SATURDAY THROUGH MONDAY/... As of 100 AM EDT Tuesday... Key Points: 1. Dry still for Saturday. 2. Progressively greater potential for showers/storms Sunday into Monday. 3. Temperatures above normal all three days. A look a the 30 Jun 12Z NCEP Ensemble Mean 500mb Geopotential Heights shows a ridge axis extending from the Great Lakes to Florida on Saturday. A shortwave trough is expected to be over the Central Plains states while a broader trough remains parked over far western CONUS. On Sunday, ridging remains over our region. The Central Plains shortwave trough advances toward the Great Lakes region. The far western CONUS trough amplifies. On Monday, little change is expected in the overall synoptic pattern as compared to Sunday. At the surface, the center of surface high pressure shifts east to off the NJ coast. A front/trough will extend from Hudson Bay to the Central Plains states. On Sunday, ensemble averaging removes any specific location of the center of the surface high. However, a ridge axis is expected to be situated from the western Atlantic to over the Carolinas and into the Tennessee Valley. A baroclinic zone will extend from southern Quebec to the Central Plains. On Monday, the ridge axis weakens and shifts a bit into the western Atlantic. The baroclinic zone edges closer to the Ohio Valley. A look at the 30 Jun 12Z NAEFS Ensemble Situational Awareness data shows 850mb temperatures around +19C through the period. The above weather patterns offers the following forecast. High pressure will slowly lose its influence over the region as its center slowly progresses eastward. Concurrently, a front will make gradually headway southeast towards the region. While Saturday still looks like a dry day for the region, progressively Sunday into Monday, the coverage of diurnal showers/storms will increase across the area. Temperatures will average five to eight degrees above normal each day. Confidence in the above weather scenario is moderate to high. && .AVIATION /13Z TUESDAY THROUGH SATURDAY/...-- Changed Discussion --As of 915 AM EDT Tuesday... Unsettled weather likely this afternoon and evening as a cold front crosses the the region preceded and accompanied by numerous to widespread showers and thunderstorms. Showers and storms will likely impact most if not all taf sites during the afternoon, leading to sub-VFR flight conditions at times. High-res models indicate storms will fire along the Blue Ridge first, from TNB-HLX, and along the Appalachian Divide from MKJ-BLF to just NW LWB. Have VCTS for most sites by 16-20z time frame then enough coverage of storms to have moderate TSRA in at all TAF sites in the late afternoon/early evening 20-01z time frame. Some storms could produce gusty winds of 20-25+ knots but most of the time winds will be southwest to west under 10kts. Showers/storms will be decreasing overnight with potential for IFR to LIFR cigs with MVFR to IFR vsbys. Confidence is low on how low cigs will go but higher confidence on sub-VFR conditions after midnight local time. EXTENDED AVIATION OUTLOOK... Passage of a cold front will bring bring drier conditions back to the region for Wednesday and Thursday. VFR conditions are expected outside of morning valley fog Wednesday through next weekend, with only isolated chances for showers and thunderstorms expected late in the week.-- End Changed Discussion --&& .RNK WATCHES/WARNINGS/ADVISORIES... VA...None. NC...None. WV...None. && $$ SYNOPSIS...WP NEAR TERM...PM/WP SHORT TERM...DS LONG TERM...DS AVIATION...JCB/PM/WP