Area Forecast Discussion
Issued by NWS Paducah, KY
Issued by NWS Paducah, KY
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043 FXUS63 KPAH 251135 AFDPAH Area Forecast Discussion National Weather Service Paducah KY 635 AM CDT Sat May 25 2024 .KEY MESSAGES... - Sunday has the potential to be a very volatile day with 2 rounds of severe weather possible. The range of possibilities covers everything from the pre-dawn period through the evening. Confidence in the timing and location details remains low, but tornadoes, damaging winds, large hail, and flash flooding will all be possible. - A much needed respite from the active weather pattern is in store for next week. && .DISCUSSION... Issued at 357 AM CDT Sat May 25 2024 Convection early this morning has weakened to well below severe levels, and may take til sunrise or a bit after to clear all of west Kentucky. Once it does, Saturday should be dry throughout the region. A weak frontal boundary will slip south into the Quad State this morning, but it will eventually wash out somewhere across the region. This will bring some lower dewpoints, upper 50s, into the far north/northwest, which will take the edge off the humidity there. Otherwise, south winds will increase tonight and push the boundary back north of the area. The 00Z guidance continues to show a wide range of possibilities for severe weather Sunday and Sunday night. Guidance has shifted back southward with the severe MCS expected to develop over the Plains tonight. This MCS could reach southeast Missouri before daybreak Sunday morning and could sweep eastward through the entire area as early as 15Z. The question would then be how much can the atmosphere recover for the afternoon or evening? Of course, if the morning convection does not develop or impact much of the region, then that would be more bullish for a major severe weather event in the afternoon and evening. Regardless of the timing or convective mode, the combination of shear and instability continues to look very ominous, especially Sunday afternoon and evening. The 00Z HREF mean indicates 2000-4000 J/kg of surface-based CAPE with 200-400 m2/s2 of 0-3km storm-relative helicity (SRH). The 0-1km SRH is generally in the 150-200 m2/s2 range, supportive of a tornado threat. Substantial instability could develop as early as 15Z Sunday. This parameter space would support initial supercells with all severe hazards possible. However, the initial supercells are likely to quickly develop into a severe MCS. The greatest threat at this time appears to be for widespread damaging winds in a well-developed MCS moving eastward across some portion of the region, most likely across the northern half of the area. There is a possibility of one healthy MCS in the morning and a very strong one in the afternoon or evening. We simply will not have much clarity until we see how tonight`s convection evolves over the Plains. We may not have much time to react to the convective evolution, but in the meantime we should be prepared for widespread severe weather at any time from early Sunday morning through Sunday evening. A cold front will pass slowly across the region overnight Sunday into Monday, as the upper storm system lifts northeast to the Great Lakes. A small chance of showers and thunderstorms will continue in the east through much of the day Monday, but the humidity will be decreasing through the day. Temperatures will still climb a bit above normal into the lower 80s. The Quad State will be dry from Monday night through Thursday with cyclonic northwest flow aloft and surface high pressure in control. As the trough pushes farther east, warm advection may get going for Friday into next weekend, and that results in some chance of showers across the entire region Friday through next Saturday. Temperatures will bottom out Wednesday and Wednesday night when readings will be at or a few degrees below normal, especially the lows. Temperatures will gradually climb back above normal by Friday. && .AVIATION /12Z TAFS THROUGH 12Z SUNDAY/... Issued at 635 AM CDT Sat May 25 2024 A LIFR ceiling at KMVN should quickly lift to MVFR levels this morning, while elsewhere MVFR ceilings are expected to develop in the next hour or two. Ceilings should be up to VFR levels by around 18Z. Winds will be light through the period. && .PAH WATCHES/WARNINGS/ADVISORIES... IL...None. MO...None. IN...None. KY...None. && $$ DISCUSSION...DRS AVIATION...DRS