Area Forecast Discussion
Issued by NWS Blacksburg, VA
Issued by NWS Blacksburg, VA
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043 FXUS61 KRNK 021811 AFDRNK Area Forecast Discussion National Weather Service Blacksburg VA 211 PM EDT Tue Jul 2 2024 .SYNOPSIS... High pressure will pass over the region maintaining dry weather through Wednesday. Temperatures start to heat up again by the 4th of July, along with a chance for storms for the latter half of the week. && .NEAR TERM /THROUGH WEDNESDAY/... As of 150 PM EDT Tuesday... Key Message: 1) Temperatures climb again for Wednesday. 2) No rain expected. Skies will be mostly clear through the remainder of the day today, overnight and most of Wednesday due to surface high pressure sliding slowly to our northeast, and a powerful subtropical ridge pushing even further northeast out of the southern plains. This will also lead to increased heat and moisture in the area. Highs Wednesday mostly in the 80s for mountain areas, and just pushing into the 90s in the Piedmont, Southside and central VA. Dewpoints in the mid 60s will start to make it feel like a sticky heat Wednesday, while the previous few days have been dry enough to avoid that. && .SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY NIGHT/... ... As of 130 PM EDT Tuesday... Key Messages: 1. Heat index values potentially exceeding advisory criteria Friday. 2. Afternoon thunderstorms on Thursday and Friday could potentially bring locally damaging winds. Model ensembles show high confidence that the anomalously strong upper level ridge over our region is slightly flattened late this week as an upper level trof moves east from the northern plains into the western Great Lakes by Friday evening. Despite this, a deepening southwest flow by Friday will push 850mb temps several(2-3+)standard deviations above normal, especially on Friday. Forecast high temperatures on Friday, generally following the NBM, will be within 2-5 degrees of record highs for most locations on Friday (See climate section below for record highs Friday and Saturday). These abnormally warm temperatures combined with PWAT values climbing 1-2 standard deviations above normal for both Thursday and Friday will lead to potentially dangerous heat index values east of the Blue Ridge, especially on Friday and will highlight this threat in the HWO. Another by-product of the flattening upper level ridge will be weak upper level disturbances emanating from northern plains/western Great Lakes upper level trof. These disturbances will help spark afternoon and early evening thunderstorms. Forecast soundings show the potential for long and skinny CAPES with a fairly healthy spread in sfc dew points and temps, creating an environment conducive for locally damaging winds and locally heavy downbursts of rain. && .LONG TERM /SATURDAY THROUGH TUESDAY/... ...As of 130 PM EDT Sunday... Key Messages: 1. Confidence remains high for above normal temperatures through the period with the warmest day on Saturday. 2. Unsettled weather persists through the long term period with afternoon/evening storms possible each day. The CPC Cluster Analysis Tools indicate above average confidence in the upper level pattern through Sunday in advance of an upper level trof in the central U.S., with confidence with the location and amplitude of the trof falls Monday and Tuesday. 850mb temps continue be 1-2 standard deviations above average on Saturday with NBM forecast high temps still well into the 90s east of the Blue Ridge with heat index values nearing advisory criteria in the far east. With the model ensembles in good agreement that an upper level trof sweeps through the northeast late Saturday/Saturday night allowing a surface boundary will move into our area, which may bring us the best chance for storms in the long term period. Forecast soundings show fairly robust DCAPE values on Saturday and even Sunday, suggesting storms will have the potential for damaging winds. Precip chances on Sunday are highest across the VA southside and NC piedmont where the surface boundary is likely to stall and temperatures may be a degree or two cooler, but still well above average. As upper level heights build back on Monday, PWAT anomalies also increase meaning scattered afternoon storms are possible anywhere across our forecast area with the continued threat for isolated damaging winds. The Colorado State Machine-Learning Probabilities Prediction Page keeps some risk for severe weather in our area each day through the period. && .AVIATION /18Z TUESDAY THROUGH SUNDAY/... As of 205 PM EDT Tuesday... Widespread VFR with limited mid to high deck clouds through the next 24 hours. Winds will be light, generally southeast to east. No precipitation expected. Confidence in the above scenario is high. EXTENDED AVIATION OUTLOOK... Terminals in the area should remain VFR with high pressure nearby through Wednesday night/early Thursday. MVFR conditions may develop by Thursday morning, with an increase in TSRA/SHRA chances Thursday through Saturday ahead of a front. Ceilings will lower to IFR/LIFR during this period. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...None. NC...None. WV...None. && $$ SYNOPSIS...PM NEAR TERM...VFJ SHORT TERM...PH LONG TERM...PH AVIATION...SH/VFJ