Area Forecast Discussion
Issued by NWS Paducah, KY
Issued by NWS Paducah, KY
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971 FXUS63 KPAH 271103 AFDPAH Area Forecast Discussion National Weather Service Paducah KY 603 AM CDT Sat Apr 27 2024 .KEY MESSAGES... - The pattern remains unsettled and unseasonably warm through next week with multiple chances of showers and thunderstorms. The greatest risk for widespread rain is late Sunday through Monday afternoon as a cold front slowly moves through. - There is low confidence in the severe weather potential over southeast Missouri and southern Illinois late Sunday into Sunday night. Heavy rainfall amounts between 1 to 2 inches is expected with locally higher amounts. Localized flash flooding issues cannot be ruled out. - South winds with gusts between 20-30 mph are expected today and 25-35 mph on Sunday. && .DISCUSSION... Issued at 244 AM CDT Sat Apr 27 2024 A mild start to the morning as a 500 mb vort max is providing ascent for a band of showers across the FA. Additional isolated to scattered showers and a few thunderstorms are possible later this morning and afternoon as impulses round a ridge over the SE CONUS. The greatest risk for pcpn is west of the Mississippi as areas to the east are likely to remain dry. Any isolated convection that does manage to develop will quickly diminish tonight with the loss of diurnal heating. Pulse storms are also favored given the lack of shear. Otherwise, today will be breezy with strong southerly flow. Gusts between 20-30 mph are possible. MaxTs will be unseasonably warm in the low to mid 80s with minTs falling into the upper 60s. By 12z Sunday, a 500 mb shortwave and 80 kt jet max will be leeward of the Rockies as 1001-1003 mb sfc low pressure is progged to be located over north central Kansas with a trailing cold front. Most of the day likely remains dry as the FA will remain well in the warm sector regime. A tight pressure gradient between a frontal boundary over the Plains and high pressure off the Carolinas will allow for southerly flow to prevail with windy conditions. Wind gusts between 25-35 mph will be possible. MaxTs will once again be well above normal in the low to mid 80s with minTs in the low to mid 60s. As a leading 500 mb shortwave ejects across the central Plains with a 500 mb low located over the Dakotas, synoptic scale forcing for ascent Sunday evening will increase the risk for widespread showers and thunderstorms through Sunday night. While portions of the CWA are outlooked for severe weather by the SPC, there is still low confidence in how unstable the atmosphere will be. The 0z 3km NAM is the worse case scenario with an axis of 500-1000 J/kg of MLCAPE setting up over southeast Missouri and southern Illinois. Combined with effective bulk shear of 45-50 kts and sfc- 1km SRH between 100-200 m^2/s^2, a QLCS overnight would be favored with the main concern being damaging winds and isolated tornadoes. However, other model guidance is much more meager with the instability and favors more of a heavy rainfall concern. The 0z ensembles are in good agreement with an axis of one to two inches setting up over southeast Missouri and southern Illinois with locally higher amounts. Meanwhile, lower QPF amounts between a half to one inch are progged in southwest Indiana and western Kentucky. PWATs around 1.5 inches, a warm cloud depth of 10kft AGL, and a cloud layer mean wind that is parallel to the aformentioned frontal boundary will support training storms that will be capable of producing torrential downpours. Given the ongoing drought conditions, most locations will likely be able to handle the QPF that is progged, but a few isolated flash flooding issues cannot be ruled out in more urban areas. The good news is locations that really need the rain will benefit. In the wake of fropa on Monday as the cold front lags, numerous showers and thunderstorms will remain possible before trending drier Monday evening. The flow aloft then turns more zonal for the middle of the week favoring drier conditions on Tuesday. Daily shower and storm chances return Wednesday-Friday as multiple disturbances move through the FA. Southerly flow will allow for a warm and moist airmass to prevail with daily maxTs in the 80s. && .AVIATION /12Z TAFS THROUGH 12Z SUNDAY/... Issued at 602 AM CDT Sat Apr 27 2024 VFR conditions to start off the morning with mid level clouds across the region. -SHRA is possible at KCGI through 15z; otherwise, have included VCSH mention at KPAH/KMVN where confidence is much lower. Some isolated convection may try to develop this afternoon across portions of southeast Missouri and southern Illinois, but the probability of impacting the terminals is 30-40% at best. Breezy southerly winds around 15 kts with gusts around 25 kts are expected during the day. Any isolated pcpn will quickly diminish after sunset with scattered high level clouds through the night. South winds between 10-12 kts are expected. && .PAH WATCHES/WARNINGS/ADVISORIES... IL...None. MO...None. IN...None. KY...None. && $$ DISCUSSION...DW AVIATION...DW