textproduct: Paducah

KEY MESSAGES

- Showers/storms are expected Friday with a meager chance for a few severe storms. Beneficial rainfall is expected.

- Monday's set up remains concerning for severe thunderstorms.

DISCUSSION

Issued at 111 PM CDT Thu Apr 23 2026

Sunny, warm and dry today with highs moving towards the lower 80s. Starting to see a few fair weather cu form up in the afternoon heat. A shortwave working off the southern Rockies will nudge a cold front currently bisecting the central plains and spark showers and storms that will try to start working this way overnight. The upper level ascent is pretty weak by the time it moves overhead, but there should be enough low layer warm advection and surface frontal convergence for rain and showers. The timing of the activity pre-dawn to mid-morning coupled with meager lapse rates make surface based thunderstorms look like it will be hard to come by. High-res CAMs paint a dying MCS into our western counties about 4 to 5 am that washes out amid at least some straitiform rain keeping cloud cover in place most of the morning and making afternoon instability more limited. In short, rain and showery mess and residual clouds followed by a little bit of pre-frontal clearing. There is a chance for thunderstorms in the afternoon with about 1100 J/kg of MLCAPE available but the CAMs don't really like the idea of anything much going and given the thermodynamics and weak large scale ascent I think they probably have a point.

Most of the attention of the day has been on Monday. During the late morning and afternoon the general troughiness currently over southwest Canada continues to work with a zonal polar/subtropical jet maxima at about 110 kts to squeeze off a sharp shortwave over Kansas and Iowa. A surface low forms in the lee of the Rockies and moves northeastward into MN/WI at about 990-993mb depending on which model you are looking at. Low-layer flow increases in reponse with 850mb flow averaging about 45 to 55 kts between 21 and 00z amongst the 12z determinstic and ensemble suite. Rich and deep boundary layer moisture moves in from the western Gulf and Bay of Campeche. Deterministic guidance has values in the southern CWA between 69 and 71. The GFS ensemble has the 10th percentile at 67 and the 90th percentile at 71. A modest capping inversion from a weak EML overspreads the region Monday morning and height changes stay pretty neutral til about 21z before turning sharply negative once sharply diffluent flow moves overhead Monday afternoon.

By late afternoon an average of available global-scale model guidance would give us around 2500-3000 J/kg of MLCAPE with mid level lapse rates around 7 to 7.5 C/km, dewpoints in the high 60s to low 70s, and large sweeping hodographs with 0-1km SRH around 250-300 m2/s2. This is about where things were yesterday, if not slightly stronger. The synoptic scale pattern has been very consistent, but the shape of the jet absolutely lends itself to subtle changes that would result in the impacted area varying greatly. The sharp increase in ascent does make one think more of a quick upscale to linear convection with a wind/QLCS tornado threat, but I am concerned about the subtle residual capping and kinematic profile supporting some supercell threat in what would be a volitale environment for very large hail and tornadoes. Machine learning products are predictably spiking in response to the parameter space. This type of pattern at 108+ hours can and often does shift considerably, but the trend has been very consistent for several days now, and as much as these events wax and wane and change at this range, higher impact days also tend to lock in at great distance and not sputter and I am a little concerned we are looking at the latter.

Behind this system we look to get at least a few days of fairly dry and seasonable conditions before more unsettled conditions approach for the weekend.

AVIATION /18Z TAFS THROUGH 18Z FRIDAY/

Issued at 1223 PM CDT Thu Apr 23 2026

VFR conditions with moderate winds are forecast through the afternoon and evening. An area of showers, possibly with embedded thunderstorms is forecast to move off the plains and into the region late tonight. Ceilings should remain VFR but MVFR or IFR visby appears possible in heavy rain. Thunder chance was too low for TAF mention for now but may need to be introduced later either in the initial wave in the 09-12z time frame or in the late morning afternoon.

PAH WATCHES/WARNINGS/ADVISORIES

IL...None. MO...None. IN...None. KY...None.