Area Forecast Discussion
Issued by NWS Central Illinois
Issued by NWS Central Illinois
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213 FXUS63 KILX 270737 AFDILX Area Forecast Discussion National Weather Service Lincoln IL 237 AM CDT Mon May 27 2024 .KEY MESSAGES... - Scattered thunderstorms (20-30% chance) will pose a threat of gusty winds this afternoon into the evening, primarily between 4 PM and 9 PM. There is a level 1 of 5 risk of damaging winds. - Tuesday afternoon/evening will also feature scattered storms capable of gusty winds (20% chance), mainly north of I-74. - High pressure takes control for the latter half of the week, with dry weather Wednesday through Friday. && .SHORT TERM... (Through Late Tonight) Issued at 237 AM CDT Mon May 27 2024 Early Monday morning, sfc low pressure was positioned over the Great Lakes region, with an attendant cold front extending through north- central IN into east-central IL. As of 2am/07z the front had moved past a Danville to Taylorville line, but had not yet reached Paris- to-Effingham. A few spotty showers have developed near and just ahead of the front, so kept some low chance PoPs during the first few hours of the forecast period. These showers should be east of the area by daybreak today. Today, central IL will be in the post-frontal airmass, which will feature persistent northwest winds gusting 20-30 mph. A digging shortwave will approach from the northwest by mid-afternoon, leading to scattered showers/storms. Instability progs are rather weak, less than 750 J/kg, but forecast soundings have consistently shown a deep- inverted V profile beneath the cloud bases, which are expected to be over 4000 feet. Efficient evaporative cooling beneath these cloud bases could lead to sporadic strong downdrafts capable of producing strong wind gusts. This assessment is supported by high- res guidance, as the 27.00z HREF indicates a 20-40% chance of gusts over 45 mph with these storms. There is a marginal risk (level 1 of 5) for damaging winds. Other severe hazards (hail, tornadoes) are not expected. Radar estimates suggest that nearly all of the CWA has received at least a half inch of rain since Friday, and a majority of the CWA has received over 1". That will hopefully stymie any blowing dust concerns with these gusty thunderstorms. Erwin .LONG TERM... (Tuesday through Sunday) Issued at 237 AM CDT Mon May 27 2024 Tuesday looks fairly similar to Monday, with continued cyclonic (northwesterly) flow and another shortwave approaching during the afternoon which could kick off more showers/storms, mainly north of I-74 (20% chance). Forecast soundings for Tuesday show similar signatures to Monday, so gusty winds will once again be possible with any storms that form. Conditions are looking quite enjoyable Wed thru Fri as upper level ridging set up over the central Plains, resulting in strengthening, broad sfc high pressure over the Upper Midwest/Ontario. These features will gradually shift east during the latter half of the week, but will provide mostly dry weather Wednesday-Friday while temperatures steadily warm each day. By Fri, highs return to near normal, around 80F. Dewpoints in the upper 40s/low 50s will make it feel quite refreshing. Into the weekend, the upper ridge shifts east while a trough approaches from the west, returning precip to the forecast Sat- Sun. Early indications are that the severe weather potential with this system is quite low, owing to limited moisture return. Erwin && .AVIATION... (For the 06z TAFs through 06z Monday Night) Issued at 1158 PM CDT Sun May 26 2024 A cold front will continue to push through the central IL terminals for the first few hours of the forecast period, with little or no chance for any precipitation developing along the front at this point. However, an area of MVFR cigs is poised just upstream, and is expected to move over most of the area overnight. Lifting and dissipation of this cloud cover should result in VFR conditions by 13Z-16Z. Another shortwave will arrive in the afternoon, resulting in widely scattered showers and thunderstorms mainly near and north of the I-74 corridor until around 04Z. Winds NW around 10 by 06Z-11Z, increasing to 12-16 kts with gusts 20-25 kts by 16Z. Winds decreasing after 01Z. 37 && .ILX WATCHES/WARNINGS/ADVISORIES... None. && $$