Area Forecast Discussion
Issued by NWS Central Illinois
Issued by NWS Central Illinois
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953 FXUS63 KILX 160043 AFDILX Area Forecast Discussion...Updated National Weather Service Lincoln IL 743 PM CDT Sat Jun 15 2024 .KEY MESSAGES... - Seasonably hot and humid weather is on tap for next week. Heat index values will peak at or above 100 degrees from Sunday afternoon through Monday afternoon before readings settle back into the middle to upper 90s for the remainder of the week. && .UPDATE... Issued at 743 PM CDT Sat Jun 15 2024 Thicker high clouds have been moving past the I-74 corridor and will be out of the area soon. However, skies generally remain partly cloudy west of I-55 overnight, ahead of a shortwave currently across eastern parts of South Dakota and Nebraska. A couple small MCS`s are ongoing in this area and will lift northeast overnight. Latest HRRR runs have been suggesting a glancing blow early Sunday morning northwest of the Illinois River, though general CAM solutions have been tracking it more into northwest Illinois. Went ahead and added some 20% PoP`s early morning north of a Galesburg-Pontiac line to address this possibility. Otherwise, only minor edits made to the forecast grids at this time. Geelhart && .SHORT TERM...(Tonight through Sunday Night) Issued at 228 PM CDT Sat Jun 15 2024 A 1025mb high centered over southern Ontario continues to dominate the weather across central Illinois this afternoon. 19z/2pm temperatures are in the middle to upper 80s: however, dewpoints have diurnally mixed into the lower to middle 50s...resulting in comfortable conditions. Plenty of high cloudiness from a pair of short-wave troughs over the Plains is drifting eastward, leading to a high/thin overcast everywhere north of I-70. These clouds will persist through the night as the wave currently over western Kansas lifts northeastward toward the Great Lakes. CAMs keep any associated convection along/west of the Mississippi River late tonight into early Sunday morning, but will still need to keep an eye out for an isolated shower along/north of a Rushville to Bloomington line. Lows tonight will range from the lower 60s near the Indiana border to the upper 60s to around 70 degrees in the Illinois River Valley where cloud cover will be more prevalent. As the wave lifts into the Great Lakes, boundary layer winds will veer to the SW and increase behind a departing warm front. This will bring hotter and more humid air into the region, pushing afternoon highs into the lower to middle 90s. Thanks to dewpoints climbing well into the 60s to around 70 degrees, Sunday afternoon heat index values will peak around 100 degrees. Barnes .LONG TERM...(Monday through Next Saturday) Issued at 228 PM CDT Sat Jun 15 2024 The hottest day of the forecast period will be Monday when air temperatures reach the middle 90s and heat index values climb into the 100-105 degree range. The one mitigating factor for the heat will be southwesterly winds gusting 20-25mph. As has been seen by the past several model runs, increasing deep-layer moist advection from the western Gulf of Mexico will lead to an increase in cloud cover and the development of widely scattered convection Monday afternoon. The same scenario will unfold on Tuesday, with the increase in cloud cover leading to less hot high temperatures in the upper 80s and lower 90s and heat index readings below 100 degrees. After that, seasonably hot and humid summer-like weather will prevail for the remainder of the extended...with periodic very low chance PoPs. It does not appear any significant frontal boundaries will push into the region, so any convection that occurs will remain widely scattered and disorganized Wednesday through Saturday. Barnes && .AVIATION... (For the 00z TAFs through 00z Sunday Evening) Issued at 606 PM CDT Sat Jun 15 2024 VFR conditions to continue the next 24 hours, with periods of high level clouds, though scattered clouds near 5000 feet will develop Sunday morning. Southeast winds around 10 knots will trend more southerly by morning. Geelhart && .ILX WATCHES/WARNINGS/ADVISORIES... None. && $$