FXUS63 KPAH 181739 AFDPAH Area Forecast Discussion National Weather Service Paducah KY 1239 PM CDT Mon May 18 2026 .KEY MESSAGES... - Breezy today with thunderstorms becoming a factor by the afternoon (50-70% chance). Some risk (level 1 to 2 of 5) for severe thunderstorms exists with wind and hail the main threat. - High rain chances (80-100%) from Tuesday afternoon into Tuesday night. Level 2 of 5 severe weather risk but the deep layer shear may be too weak. Locally heavy rain possible but storm organization may be too lacking for optimal rainfall rates. - Drier conditions briefly behind a cold front but rain and thunderstorms (and humidity) come back by Thursday into Friday. && .UPDATE... Issued at 1239 PM CDT Mon May 18 2026 Updated the aviation section for the 18Z TAF issuance. && .DISCUSSION... Issued at 118 AM CDT Mon May 18 2026 Things continue to move roughly in line with expectations in the near term, wetter in the medium/long-range. For today watching a shortwave over south central Texas that is progged to be overhead by 20-21z and looks to interact with our increasingly soupy airmass with dewpoints in the mid 60s to low 70s. Convection allowing models suggest the MCS over MO/KS may make it (in some form) into the region by about that time as well. The upper support looks a little lacking but may be sufficient to keep something going the trend is at least for it to generate some sort of differential heating boundary that may be a foci for convective initiation in the heat of the day. MLCAPEs are around 2000-2500 J/kg. Deep layer shear is 35-40 kt with the approaching wave, low shear is not too worrisome although a mesoscale boundary from the MCS could complicate the tornado factor a little. That risk appears highest along the I-64 corridor roughly, where it looks like most of the rest of the CWA could see isolated to scattered cells/complexes. These do appear they'd have the ingredients for wind/hail through the afternoon. Breezy conditions again today and did hoist another targeted Lake Wind Advisory. Tuesday a surface cold front still works close to the area as we begin to feel the lifting influence of the right rear exit region of a northern Plains/Great Lakes jet max. PWATs are high, layer warm-air advection is moderate, jet level ascent/height falls are supportive and you'll have the front in the area as well. We should end up with scattered to numerous showers and storms with a window for locally heavy rain - although there still really aren't any tools that go too nuts. HREF PMMs max out at 1.5 inches or so and it would take quite a bit more than that to flood given our antecedent conditions. Severe weather wise the instability will be there, the low shear is ok but the deep layer shear really backs off through the day and we may not quite have enough oomph there to help significantly organize convection. This may be part of why the CAM based precip guidance is so weak, things just will be too sloppy to produce optimal rainfall rates. The medium and long range trend is definitely for more persistent troughiness over the central plains and Rocky Mountains. Late Wednesday into Thursday may be a little drier/less humid but by Friday the warm front sweeps back to the north putting us firmly back into the soup. Shear/instability Friday may line up to produce a little severe weather potential with ECMWF/GFS agreement on shear and instability. After that fairly large differences in deterministic and ensemble positioning and shape of the cut off/closed lows/shortwave troughs that spit out of this system get pretty jumbled. On balance however generally humid and unsettled weather appears a reasonable bet. Hopefully with enough rain to ameliorate our drought conditions at least a little. && .AVIATION /18Z TAFS THROUGH 18Z TUESDAY/... Issued at 1239 PM CDT Mon May 18 2026 Scattered shower and thunderstorm activity will continue to develop this afternoon and increase in coverage. Heavier banding is located just north of KMVN and will remain through the afternoon while, across the Quad State, showers and storms are moving in from the southwest. Locally heavy rain is possible, and lightning is likely to be a factor several hours in a row for some sites. The Kentucky Pennyrile area has the least potential for thunder. MVFR cigs are possible with storms, as are vsby reductions to MVFR or IFR. A few stronger storms are possible. Breezy winds gusting to 18-25kts today drop to around 8-10kts sustained overnight, then become breezy again tomorrow. Dry weather is forecast later tonight into tomorrow with rain beginning to re-enter the picture in the west at the end of the TAF period. && .PAH WATCHES/WARNINGS/ADVISORIES... IL...Lake Wind Advisory until 4 PM CDT this afternoon for ILZ075- 081-085. MO...Lake Wind Advisory until 4 PM CDT this afternoon for MOZ100. IN...None. KY...Lake Wind Advisory until 4 PM CDT this afternoon for KYZ007>009-011-012. && $$ UPDATE...ATL DISCUSSION...JGG AVIATION...ATL