Area Forecast Discussion
Issued by NWS Central Illinois
Issued by NWS Central Illinois
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182 FXUS63 KILX 222343 AFDILX Area Forecast Discussion...Updated Aviation National Weather Service Lincoln IL 643 PM CDT Wed May 22 2024 .KEY MESSAGES... - There is a 70% chance for thunderstorms Friday, with a level 1 of 5 (marginal) risk some of these storms become severe. The strongest storms could produce damaging wind gusts and large hail. - Scattered thunderstorms are likely (70-80% chance) on Sunday with severe storms possible. && .DISCUSSION... Issued at 314 PM CDT Wed May 22 2024 The cold front that passed through the area last night has pushed deep into southern IL and currently lies in the OH River Valley. Some showers and isolated thunderstorms have pushed into the Taylorville area and may bring some light accumulations of rain to parts of the south and eastern zones through the rest of the afternoon hours. The upper wave associated with these showers is expected to clear central IL by the evening hours. A strong or marginally severe storm is possible in the far southern zones (Crawford, Clay, Richland, Lawrence), but trends have signaled the likelihood is decreasing. We may see a return of showers/storms late tonight in the far south in the vicinity of the stationary front. Otherwise, expect Thursday to be rather quiet weather-wise with highs in the low 80s with sunny skies north and partly sunny skies south near the stationary front. On Friday, an upper wave will move from the Northern Rockies and into the Northern Plains, becoming negatively tilted. The surface low will stay in the Northern Plains, but cold front will push east into IL. We`ll see a surge of high theta-E air north into IL on Friday ahead of the front, but the upper support will remain to the north. As a result, we`ll just see a Marginal Risk for severe storms on Friday. MLCAPE will be around 3000 J/kg and deep shear around 25-35 kts, although some models have more shear. We`ll see a break on Saturday as high pressure moves in over the area behind Friday`s cold front. Sunday looks to have the best chance for severe weather in the next seven days. We`ll see better upper support as an upper wave moves through the area. We`ll likely have a lead shortwave Sunday morning followed by the main wave Sunday afternoon/evening. Central IL is currently in a 15% (Slight) risk for severe weather for Sunday given +3000 J/kg of CAPE and 40-55 kts of deep shear. The area could see 1 to 2" of rain with this system as well. Northwest flow is expected for Monday and Tuesday, with some light showers possible in the northwest flow to start the week. Generally, expect a break from precipitation by midweek next week. Knutsvig && .AVIATION... (For the 00z TAFs through 00z Thursday Evening) Issued at 643 PM CDT Wed May 22 2024 VFR conditions expected across the central IL terminals over the upcoming 24 hours as high pressure along with a relatively dry air mass drift across the area, while showers associated with a frontal system to the south remain confined to areas south of the central IL terminals. Other than mid level cloud cover affecting some of the I-72 terminals overnight, mostly clear skies can be expected until diurnal cumulus around 5000 ft AGL develop after 16Z. Winds W 7-12 kts until 01Z, then becoming light and variable overnight. Winds returning from the SE 6-10 kts after 16Z. 37 && .ILX WATCHES/WARNINGS/ADVISORIES... None. && $$