Area Forecast Discussion
Issued by NWS Blacksburg, VA

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516 FXUS61 KRNK 300643 AFDRNK Area Forecast Discussion National Weather Service Blacksburg VA 243 AM EDT Thu May 30 2024 .SYNOPSIS... Cold front pushes to the coast tonight. Dry and cooler high pressure will build in for Thursday and Friday with below normal temperatures. The next chance of rain will be late this weekend. && .NEAR TERM /THROUGH TONIGHT/...
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As of 200 AM EDT Thursday... Key Messages: 1) Dry and mostly sunny conditions today. Temperatures below normal. Troughing over the east remains in place today with northwest flow persisting. 850mb jet modeled around 30 to 35kts and this will be enough to remain well-mixed overnight, especially over the ridges. Highest elevations still gusting close to 20mph. Being well- mixed and coupled with large dew point depressions, fog development seems rather unlikely through this morning. Trough amplifies today and shifts east into the Atlantic late tonight. Will have strong Canadian high pressure build in behind the trough bringing clear and calm skies tonight. Chilly temperatures are expected overnight and will see widespread mid to low 40s. Some sheltered elevated valleys may even reach the upper 30s. Daytime highs in the upper 60s to 70s.
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&& .SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/... Issued at 240 PM EST Wed May 29 2024 Key Message: - Generally quiet weather and below normal temperatures expected through the end of the week. The big story for the end of the week will be below normal temperatures for early June. An upper-level trough should gradually move eastward across the Mid-Atlantic and Northeast U.S. through the end of the week. As this occurs, a surface high will be pushed across the region. With a northerly flow through the boundary layer, continued low-level cold air advection will continue through the end of the week, as weak perturbations continue rounding the base of the upper trough. This, combined with a continued dry airmass, will allow below normal temperatures to be seen. Deterministic guidance for this period remains on the lower end of the statistical guidance spectrum during this period, with most values appearing to hover between the 10th and 25th percentile. This is true especially for overnight lows. Based on everything I`m seeing, I plan on going below the guidance mean for temperatures this afternoon. In other words, we`re already doing this in the forecast and I see no reason to buck the trend. It looks like the coldest night will be Thursday night/Friday morning. The upper trough axis should shift offshore Friday night, allowing shortwave ridging to build into the region from the west. While we still might see a weak north to northeast low-level flow heading into the weekend, temperatures will begin to moderate. By the time Saturday rolls around, winds should become southerly as the surface high shifts east of our area. With low-level moisture increasing, expect more cloud cover to join the slowly warming temperatures. && .LONG TERM /SUNDAY THROUGH WEDNESDAY/... Issued at 245 PM EST Wed May 29 2024 Key Messages: - Precipitation probabilities return to the forecast area. - Temperatures return to near normal levels for early June. An atmospheric disturbance is forecast to move from the Upper Midwest into the Great Lakes Sunday. There should be some flattening of the upper-level flow in response, with the boundary layer flow becoming southwesterly - or maybe west-southwesterly - and precipitable water levels increasing to near normal for this time of year (which is somewhere around an inch). The added moisture, combined with slightly better forcing, should allow cloud cover, as well as shower probabilities, to return to our area at some point Sunday. Right now, I`ve got a fairly low confidence in the timing of any precipitation Sunday. But it looks like areas east of the Blue Ridge will have greater odds in the afternoon, with no one particular time of day favored for showers west of the Blue Ridge. Beyond Sunday, about the best I can say is that it looks like unsettled weather conditions could continue. Overall, though, I have fairly low confidence in the overall evolutionary details of the forecast. The upper-level flow should more-or-less remain zonal through early next week. This will allow quick-moving shortwave troughs in the northern stream to dart across (or at least very close) to the region. Boundary layer moisture should remain ample for convection through Day 7, with precipitable water values at or above normal for early June. In fact, there is some indication in ensemble guidance of values approaching 2 standard deviations above normal (98th percentile). We`ll see what happens, though. Regardless of the details, it looks like scattered convection will be seen through the middle of next week. Temperature-wise, it looks like there will be gradual warmup through the long term portion of the forecast. I`m pretty confident that temperatures will go above seasonal levels, but I`m not sure to what extent. At this stage, I`ll stick pretty close to the national blend, which has highs by Wednesday around 80 in the mountains and in the upper 80s across the Piedmont/Southside Virginia. && .AVIATION /06Z THURSDAY THROUGH MONDAY/...
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As of 220 AM EDT Thursday... MVFR across the mountains and VFR east of the mountains through this morning. Upslope clouds will continue to bring BKN 1kft to 3kft cigs through daybreak. Should see upslope clouds dissipate late morning and all terminals are expected to remain VFR through the 24 hour TAF period. Removed any mention of fog in the TAFs as conditions still remain well mixed. Confidence is very low that there will be any fog this morning. EXTENDED AVIATION OUTLOOK... VFR much of the week, aside from potential fog at LWB/BCB early in the mornings. Storms may bring sub-VFR Sunday afternoon through Monday but low confidence.
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&& .RNK WATCHES/WARNINGS/ADVISORIES... VA...None. NC...None. WV...None. && $$ SYNOPSIS...BMG NEAR TERM...BMG/WP SHORT TERM...DB LONG TERM...DB AVIATION...BMG