Area Forecast Discussion
Issued by NWS Central Illinois
Issued by NWS Central Illinois
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528 FXUS63 KILX 141049 AFDILX Area Forecast Discussion...Updated Aviation National Weather Service Lincoln IL 549 AM CDT Fri Jun 14 2024 .KEY MESSAGES... - Slightly cooler and less humid conditions arrived today through Saturday with highs in the mid to upper 80s and lows tonight in the upper 50s and lower 60s. - A prolonged period of unseasonably hot and humid weather will occur Sunday through much of next week. High temperatures will be in the low to mid 90s Sunday through Friday, with afternoon heat indices rising to 95 to 100 degrees, and likely surpassing 100 degrees Monday afternoon. && .DISCUSSION... Issued at 345 AM CDT Fri Jun 14 2024 An MCS had brought some severe storms to areas from I-72 north during Thu evening with damaging wind reports most common east of Peoria to north and east of Bloomington. Radar mosaic shows isolated convection lingering along and south of I-72 and north of I-70 at 345 am and tracking ESE around 25 mph. A frontal boundary was just se of the IL river while an outflow boundary from convection extended from St Louis to Decatur to Danville. PW values of 1.5-1.75 inches over central parts of MO and IL helped produce a few bands of 1-2 inches of rain over northern half of CWA. CAMs have not been so great with handling this convection, though HRRR appears to have best track record and it diminishes the convection from I-72 south early this morning as it tracks into southeast IL. Cold front to move se of Lawrence county by noon with front pushing into central KY and southern MO by 7 pm. Redevelopment of isolated convection during mid/late afternoon to occur in southeast Indiana and sw MO. Mostly cloudy to overcast skies south of I-74 early this morning, to see clouds decreasing from north to south during today as skies trend sunny to mostly sunny this afternoon over area. Highs today in the upper 80s with southeast IL near 90F. Dewpoints in the mid 60s to near 70F early today to lower into the mid 50s to near 60F during the afternoon with north winds. Weak high pressure over the Dakotas and MN to drift eastward across the Great Lakes tonight and Saturday, providing fair weather to IL. Upper level high pressure also riding into IL on Saturday as 500 mb heights rise to 586-589 meters on Saturday. Cooler lows tonight in the upper 50s and lower 60s with fair skies and ENE winds less than 10 mph. Increasing mid/high clouds on Saturday especially over the IL river valley with highs in the mid to upper 80s. Comfortable dewpoints in the 50s to near 60F with SE winds increasing to 10-15 mph by Sat afternoon. Lows Sat night in the mid 60s in eastern IL and upper 60s to near 70F over central and western CWA, mildest over west central IL toward the MS river valley. Convection chances appears to stay nw of central IL overnight Sat night and Sunday as short wave trof moves into the upper MS river valley. Best chances of thunderstorms to be over IA/WI. Meanwhile a strong 593 dm 500 mb high strengthens over the southeast States and breezy southerly flow on Sunday brings back heat and humidity. Highs Sunday of 92-95 with dewpoints in the mid to upper 60s giving afternoon heat indices in the upper 90s with western CWA having HI`s near 100F. Mild lows Sunday night in the mid 70s, with some lower 70s in eastern IL. Monday appears to be the hottest day with highs of 95-98F and afternoon heat indices peaking 100-105F. Will be close to heat advisory criteria of 105F especially over the IL river valley. Isolated convection possible Monday afternoon with increased deeper moisture over the MS river valley on western side of strong upper level ridge over the mid Atlantic States. The strong 500 mb ridge shifts into southern New England on Wed with 500 mb heights rising toward 600 meters in southeast NY area. The strong upper level ridge goes back into the mid MS river valley and keeps hot and muggy conditions going through much of next week with highs in the lower to mid 90s and afternoon heat indices of 95 to 100F and possibly higher. The NWS Heat Risk experimental parameters shows major to extreme levels of heat over CWA Monday through Thu. This is an unusually long heat wave for so early in the season for central/se IL. The "ring of fire" around this strong upper level ridge has convection chances mainly nw of IL though we could see isolated convection during the afternoon and evening hours. Some signals of a weak front pushing se into central IL next Thu night and Fri could bring better chance of convection. 07 && .AVIATION... (For the 12z TAFs through 12z Saturday Morning) Issued at 550 AM CDT Fri Jun 14 2024 Aside from patchy shallow fog with brief MVFR vsbys possible until 13Z/8 am, VFR conditions are forecast to prevail across the central IL airports through 12Z/7 am Saturday. Few to scattered mid level clouds with bases of 8-10k ft along I-72 until mid morning otherwise just few-sct cirrus clouds through tonight. Any cumulus cloud developing this afternoon occuring in southern IL. Variable winds around 5 kts at dawn will become north at 7-11 kts with gusts 15-19 kts after 15Z and diminish back to around 5 kts by 01Z/sunset. NNE winds early this evening veer ENE overnight. Very patchy shallow ground fog possible by dawn Saturday but too limited to mention in central IL TAFs. 07 && .ILX WATCHES/WARNINGS/ADVISORIES... None. && $$