Area Forecast Discussion
Issued by NWS Blacksburg, VA
Issued by NWS Blacksburg, VA
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024 FXUS61 KRNK 230714 AFDRNK Area Forecast Discussion National Weather Service Blacksburg VA 314 AM EDT Mon Sep 23 2024 .SYNOPSIS... High pressure is situated across the Mid-Atlantic today, wedged against the eastern face of the Appalachians. A slow-moving cold front will meander along the Ohio River Valley over the next several days, triggering rounds of showers and thunderstorm activity that will persist through much of the workweek. Low pressure lifting northward from the Gulf of Mexico toward the end of the week may bring more widespread rainfall to the region. && .NEAR TERM /THROUGH TONIGHT/... As of 250 AM EDT Monday... Key Messages: 1) Widespread cloud cover today, with rounds of widely scattered showers and thunderstorms mainly impacting the mountains during the morning and afternoon. 2) Clouds may break in spots during the afternoon to allow for some sunshine. Highs will generally reach into the 70s. 3) Cloudy again tonight with patchy fog and periods of drizzle. Surface observations indicate that high pressure extends southward from New England across the Mid-Atlantic this morning, wedged against the eastern face of the Appalachians. Winds generally from the east are bringing Atlantic moisture inland, resulting in widespread low clouds. The combination of moist air from the Outer Banks region and cloud cover is helping to maintain mild temperatures overnight, ranging from the mid to upper 60s for most of our area. Further west, keeping an eye on spotty showers and a few thunderstorms passing east across West Virginia ahead of an approaching cold front. For today, rounds of widely of showers and thunderstorms will push across southeast West Virginia and western Virginia through the day. Have entered likely chances for rain in the forecast for this morning and again during the afternoon given multiple waves of energy that will approach ahead of the cold front, however there is low confidence on the actual timing of this activity. Believe rounds of rainfall will move across the mountains in broken lines of hit-and-miss activity, with some locations receiving multiple rounds of rain and others receiving very little, if any. However, do think that showers and storms will diminish while advancing east across the mountains due to downsloping, such that there won`t be much left of the activity once it passes east of the Blue Ridge. Outside of rainfall, low ceilings will linger into the afternoon before breaking up or lifting, but do think some areas will see sunshine for a few hours during late afternoon before low clouds fill back in during the evening. Widespread clouds and scattered rainfall will make for cooler afternoon highs today, generally holding in the 70s. Believe most rainfall will diminish for tonight, with only occasional shower activity. However, pockets of drizzle will be possible given the continued fetch of moist Atlantic air being forced into the higher terrain. Overnight lows will hold in the low to mid 60s. Confidence in the near term is moderate. && .SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/... As of 200 AM EDT Monday... Key Messages: - Daily showers and storms for the first half of the week - Near normal temperatures A shortwave coming around a trough in the northern Plains and on the outer rings of an upper level ridge moving off the southeast coast, will have rain in the area Tuesday morning, but should exit by lunch time. A slow moving cold front will approach the region in the afternoon, bringing a chance for showers and thunderstorms into the area Tuesday afternoon and evening. This front is expected to stall over the Tennessee and southern Ohio Valleys Tuesday night. On Wednesday, the trough in the Midwest becomes a closed low, ejecting another shortwave into the area. This wave is expected to track along the stalled boundary just west of the mountains. Showers are likely across the mountains with rainfall amounts ranging between a quarter to a half of an inch Wednesday. Near normal temperatures are expected through the period. && .LONG TERM /THURSDAY THROUGH SUNDAY/... As of 230 AM EDT Monday... Key Messages: - A potential tropical system in the Gulf of Mexico could bring impacts to our area on Friday, but confidence is currently low. - Cooler than normal temperatures expected this weekend. A complex weather pattern sets up Thursday and remains into early next week. A closed low forms over the Midwest by Thursday with high pressure off the southeast coast. Both systems will not move much Thursday and Friday. A tropical system coming out of the Gulf will move in between these two systems. The 00Z models are suggesting this tropical wave will track across the Tennessee Valley on Friday then gets absorbed into the the low over the Midwest on Saturday. The Midwest low pressure is forecast to move over the Ohio Valleys on Monday. At this time, forecast confidence is low, therefore will carry chance PoPs through the period. Near normal temperatures are expected Thursday and Friday, then cooler than normal over the weekend. && .AVIATION /07Z MONDAY THROUGH FRIDAY/... As of 245 AM EDT Monday... IFR ceilings have set in across the Piedmont this morning, with cloud bases below 1kft. Ceilings continue to lower as well across the mountains, with a mix of MVFR and IFR bases. Keeping an eye on broken lines of showers and a few thunderstorms advancing east across West Virginia this morning, with the energy supporting this activity expected to pass across the service area later this morning into the afternoon. IFR ceilings will be slow to lift/scatter today, lingering into mid-afternoon before breaking to VFR in some spots, but remaining MVFR in others. Low confidence in where VFR conditions will develop today, but it will be most likely during late afternoon, and will be only for a few hours before IFR ceilings redevelop this evening. Timing and location of showers and thunderstorms will also be challenging, with little run-to-run consistency in the rapid update weather forecast models, though better chances will be across the mountains. Much of the guidance suggests that rainfall will diminish in the downslope flow as it passes east toward the Blue Ridge. IFR ceilings will be widespread tonight, with pockets of drizzle expected. A few showers will move across the area from time to time as well. Wind speeds will generally remain less than 10kts through the period. EXTENDED AVIATION OUTLOOK... MVFR/IFR stratus and fog are expected to occur in rounds through at least the middle of the week, and increasingly likely to persist through the end of the workweek. Rounds of showers and thunderstorms will also continue to pass across the lower Mid- Atlantic. Low pressure lifting northward from the Gulf of Mexico toward the end of the week may bring more widespread rainfall and sub- VFR conditions to the region. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...None. NC...None. WV...None. && $$ SYNOPSIS...NF NEAR TERM...NF SHORT TERM...CG/RCS LONG TERM...CG/RCS AVIATION...NF/SH