Area Forecast Discussion
Issued by NWS Paducah, KY
Issued by NWS Paducah, KY
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358 FXUS63 KPAH 261947 AFDPAH Area Forecast Discussion National Weather Service Paducah KY 247 PM CDT Thu Sep 26 2024 .KEY MESSAGES... - Clouds will increase from the east this afternoon and evening. A chance of showers and thunderstorms will also spread west through the afternoon and evening. - Widespread showers with heavy rain will set in after midnight tonight and continue through Friday evening, as the remnants of Hurricane Helene interact with an upper-level storm system near the Quad State. Forecast rainfall in this period currently ranges from around 2 to 5 inches across the area. Some locally higher amounts cannot be ruled out. - A flood watch and wind advisory have been issued due to conditions from the remnants of Hurricane Helene. - The rains will become lighter and more isolated through the weekend. - The Quad State will begin to dry out on Tuesday as a cold front passes. Highs in the 70s and lows in the 50s are expected Tuesday through next Thursday. && .DISCUSSION... Issued at 216 PM CDT Thu Sep 26 2024 All eyes are on Hurricane Helene this afternoon as it heads for the Florida coast. Locally, we are in the calm before the storm as high pressure at the surface sits across the Midwest. Already seeing a tightening pressure gradient across the southeast which is allowing winds to begin to pick up. Aloft, an upper level low continues to sit nearly directly over the area with a downstream ridge axis just offshore the east coast. The NHC forecasts Helene to make landfall this evening and make a beeline north into the Tennessee Valley by Friday afternoon. From there it gets caught up in the upper low across our region which rotates the remnant circulation around the area into the weekend. A few scattered showers and storms are possible this afternoon and evening before the better moisture pushes in late tonight. The main forecast concerns for late tonight and Friday will be potentially heavy rainfall and gusty winds. WPC QPF is generally around 2-5 inches. There are plenty of signals in the guidance to support these numbers. The amount of upper level dynamics involved are impressive supporting plenty of deep layer lift. There will be plenty of anomalous moisture and moisture transport in place within strong 850mb convergence atop the area to support heavy rainfall at times. The best time for heavy rainfall and the heaviest QPF looks to fall from late tonight through Friday. The upper low starts to move east and weaken helping to reduce coverage of showers Friday night into Saturday. A Flood Watch has been issued for portions of the area. This flood watch could be expanded further if trends support it. There is still some uncertainty surrounding the winds. There has been a increasing concern for higher wind gusts on Friday. Forecast wind gust values have increased across the board with most areas seeing near or above advisory criteria. The pressure gradient alone should support some of these winds. While forecast soundings show very poor lapse rates within a saturated column, just a bit momentum transfer would likely be enough, and even some of the rain showers may pull down these higher winds aloft. Confidence has increased enough to support the issuance of a wind advisory for the entire area for Friday. Refer to the NPW product for further details. The system lingers across the Ohio Valley Saturday into Sunday but should be weakening. On and off rain showers will linger well into Saturday and by Sunday things will start to dry out. An upper level trough will dig into the northern plains and Great Lakes and should kick the remnants of the upper low and tropical system to the northeast. A cold front will make its way through the region Tuesday bringing much cooler and continued drier conditions for Wednesday and Thursday. && .AVIATION /18Z TAFS THROUGH 18Z FRIDAY/... Issued at 1241 PM CDT Thu Sep 26 2024 Northeast winds will further increase overnight and especially on Friday. Sustained winds 15-20 kts or higher are expected late tonight into Friday. Wind gusts as high as 30 kts or higher are also possible. Conditions will deteriorate tonight associated with moisture from Hurricane Helene. VFR conditions at the start will gradually decrease to IFR overnight through Friday. Scattered showers and storms are possible this afternoon mainly across western Kentucky but widespread rain showers will overspread the entire region from east to west late tonight and continue through the period Friday. && .PAH WATCHES/WARNINGS/ADVISORIES... IL...Wind Advisory from 7 AM Friday to 1 AM CDT Saturday for ILZ075>078-080>094. Flood Watch from 1 AM CDT Friday through Saturday morning for ILZ085>094. MO...Wind Advisory from 7 AM Friday to 1 AM CDT Saturday for MOZ076- 086-087-100-107>112-114. Flood Watch from 1 AM CDT Friday through Saturday morning for MOZ110>112-114. IN...Wind Advisory from 7 AM CDT /8 AM EDT/ Friday to 1 AM CDT /2 AM EDT/ Saturday for INZ081-082-085>088. KY...Wind Advisory from 7 AM Friday to 1 AM CDT Saturday for KYZ001>022. Flood Watch from 1 AM CDT Friday through Saturday morning for KYZ001>022. && $$ DISCUSSION...AD AVIATION...AD