380 FXUS61 KRNK 201643 AFDRNKArea Forecast Discussion National Weather Service Blacksburg VA 1243 PM EDT Sat Sep 20 2025
.SYNOPSIS... Will see some increase in clouds today as a backdoor front tracks across the area. With limited moisture, expect only spotty showers and storms mainly in the mountains. The front works back north Sunday as high pressure works back in. Low pressure over the central U.S. slowly tracks east toward the Appalachians by the middle to late part of next week increasing our chances for showers.
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.NEAR TERM /THROUGH SUNDAY/... As of 1230 PM EDT Saturday...
Key Message:
1) A few showers/storms possible this afternoon in the mountains and perhaps toward Lynchburg.
A weak backdoor front will track south this afternoon and situated over the NC/VA border this evening before retreating north Sunday. Two smaller upper level disturbances, one over northern VA and the other in the TN Valley may bring enough lift to trigger a few showers/storms mainly north of I-64 this afternoon/evening and across the southwest VA/southeast WV mountains and possibly the NRV. Overall coverage is spotty. Temperature were running warmer than previous forecast so bumped highs up a couple degrees mainly along/east of the Blue Ridge, so may see places like Danville/South Boston/Yanceyville approach 90. Any cloud cover or showers will keep it cooler in the mountains but still looking at mid or upper 70s in the higher ridges.
Tonight, cloud cover and a few areas of spotty rain linger in the wedge across the Blue Ridge before dissipating late tonight. Cloud cover will likely stay socked in north of U.S. 460 into Sunday morning, then clearing Sunday afternoon, as the front retreats north. With increasing moisture, lows tonight will range from the mid to upper 50s west to lower 60s east.
Given potential slow erosion of clouds Sunday, have highs cooler in the upper 70s to lower 80s, with some lower to mid 70s in the mountains.
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.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/... As of 300 AM EDT SATURDAY...
Key Message:
1) Rain over the mountains begins the workweek
For Monday, the first in a series of shortwaves will transit broad upper troughing, bringing weak, largely terrain driven rain showers to the western half of the CWA. This will continue on Tuesday as well.
Meanwhile, one of these waves further upstream will evolve into a cutoff low in the plains, with another separate low also forming in southern Canada. The deepening troughing due to these lows will enhance rain chances later on Tuesday.
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.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... As of 315 AM EDT SATURDAY...
Key Messages:
1) Interesting system over the plains will eventually move east bringing widespread rain late in the week
The set of upper lows mentioned in the previous portion of the forecast discussion will circle each other in an example of the Fujiwhara effect. This will hold the larger area of low pressure in and around the southern plains and Midwest for a couple of days. As the lows fuse together, the effect of the stronger combined low will encourage frontogenesis further east in the OH Valley. The timeline for this to occur is unclear, though it seems likely this front would impact southwest VA sometime Thursday or Friday, potentially bringing the most widespread measurable rain to the region since quite some time. One wouldn`t venture so far as to use the term "drought breaker", especially this far out in the forecast, but there is good confidence in a beneficial rain for areas that have seen little rain this September.
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.AVIATION /18Z SATURDAY THROUGH THURSDAY/... As of 1240 PM EDT Saturday...
VFR conditions expected through well past sunset. Showers that form will be spotty and not seeing any TAFS yet to get close to having a shower, but will amend as needed. "Best" chance will be around LWB Cigs look to lower to LIFR/IFR for most sites later tonight into Sunday morning along with possible MVFR/IFR vsbys. Exception may be BLF with VFR.
Should see a gradual improvement to VFR between 14-17z Sunday.
EXTENDED AVIATION FORECAST...
VFR into early next week, aside from any late night fog at mainly LWB. Low pressure system may bring us better chances for showers by the middle of next week with potential sub-VFR.
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.RNK WATCHES/WARNINGS/ADVISORIES... VA...None. NC...None. WV...None.
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SYNOPSIS...WP NEAR TERM...WP SHORT TERM...VFJ LONG TERM...VFJ AVIATION...AB/WP
NWS RNK Office Area Forecast Discussion