Area Forecast Discussion
Issued by NWS Central Illinois
Issued by NWS Central Illinois
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048 FXUS63 KILX 301058 AFDILX Area Forecast Discussion...Updated Aviation National Weather Service Lincoln IL 558 AM CDT Tue Apr 30 2024 .KEY MESSAGES... - Dense fog advisory in effect until 9 am for southeast IL from Shelby, Coles and Edgar counties southeast. Areas of fog along and southeast of a Danville to Shelbyville line, dense at times in southeast IL with visibilities down to 1/4 mile, should lift by mid morning. - Above normal temperatures will prevail across the area through next Tuesday May 7th, with Thursday being the warmest day with highs in the low to mid 80s and windy with southerly winds gusting 25-35 mph by Thu afternoon. - There is a chance of showers and thunderstorms late this evening and overnight, mainly over the IL river valley where a marginal risk of severe storms for gusty winds and hail west of the IL river from 10 pm to 2 am tonight. More widespread showers and thunderstorms with heavier rains expected Thursday afternoon into Friday morning. && .DISCUSSION... Issued at 400 AM CDT Tue Apr 30 2024 A weakening cold front had pushed southeast of IL early this morning with its convection now mainly southeast of Indiana over western Ohio, central KY and mid TN. Lingering stratus clouds lifting NNE over Wabash river valley of southeast IL se of a Danville to Flora line. Widespread fog from Danville to Shelbyville southeast with dense fog common from Paris to Charleston/Mattoon to Shelbyville southeast where dense fog advisory continues through 9 am today. The fog should lift by mid morning in southeast IL with the stratus clouds scattering out over the Wabash river valley during this morning. Weak high pressure over IL early this morning to drift east over the Ohio and TN river valley this afternoon, with south to SW winds increasing and approaching breezier levels later today over the IL river valley. A very nice day expected overall with ample sunshine with highs in the mid to upper 70s and more comfortable dewpoints in the 50s. A weather system over MT and WY early this morning to track eastward into the upper MS river valley by midnight and have a cold front approaching nw IL, and moving through central IL overnight as it weakens. Have a better chance of showers and a few thunderstorms by late evening over the IL river valley, with these chances diminishing at it shifts into east central IL overnight. SPC day1 outlook has marginal risk of severe storms late this evening and early overnight from the IL river west for gusty winds and hail, while tornado threat and greater risk of severe storms is west of IL this evening. Southeast IL will likely stay dry tonight. Lows overnight in the upper 50s to around 60F. Another weak high pressure ridge over IL on Wed with upper level ridging into the Ohio and TN river valleys. This to bring fair wx and lighter winds on Wed with skies becoming partly sunny. Warm highs Wed in the upper 70s central IL and lower 80s in southeast IL. A warm front lifting northward over central IL overnight Wed night into Thu morning could bring isolated convection Wed night into Thu morning especially from I-55 west. Will see higher chances of showers and thunderstorms later Thu west of the IL river ahead of approaching storm system from the central plains. Breezy southerly winds develop in warm sector on Thu with gusts 25-35 mph likely by Thu afternoon. This to bring warm highs in the low to mid 80s, a bit shy of record highs in the lower 90s on May 2nd. Surface low pressure developing over southeast CO by sunset Wed to eject ne toward the MN/WI/IA border by sunset Thu and pull a cold front east through central IL during Thu night, and thru southeast IL Fri morning. This front to likely bring showers and thunderstorms eastward over the IL river valley late Thu afternoon into Thu evening and across rest of central IL during Thu night. Best chances for convection in southeast IL is late Thu night into Friday. SPC day3 outlook for Thu/Thu night keeps marginal risk west of CWA, except reaching near Galesburg by Thu evening. WPC has slight to marginal risk of excessive rainfall over IL Thu night with higher rainfall amounts expected over the IL river valley where over 1 inch expected. Convection chances to diminish behind the cold front from west to east during Friday, with chance of showers possibly lingering into Fri evening over southeast IL. Highs Friday in the lower 70s in central IL and mid 70s in southeast IL. Models still not in the best agreement with the weekend forecast as blended models now giving a chance of showers and isolated thunderstorms on Saturday afternoon and Sat night which was dry with yesterdays runs. And latest trends for chances of shower and thunderstorms on Sunday have lowered and shifted southward. Highs this weekend in the 70s with southeast IL near 80F on Saturday. 07 && .AVIATION... (For the 12z TAFs through 12z Wednesday Morning) Issued at 555 AM CDT Tue Apr 30 2024 Patchy fog just developed at CMI airport with vsby 1.5 miles. This patchy ground fog should lift in next 1-2 hours, with generally VFR conditions forecast to prevail across the central IL airports through 12Z/7 am Wed. A cold front approaching tonight will bring a band of showers and isolated thunderstorms to PIA/IL river late this evening, to I-55 by 05-06Z and possibly as far as DEC and CMI by 07Z as it weakens. Could briefly be MVFR conditions if thunderstorms occur which look more favorable at PIA from 04-06Z. Light and variable winds early this morning to become SW near 10 kts by late morning/afternoon and increase to 10-15 kts with gusts 18-23 kts later this evening and overnight. 07 && .ILX WATCHES/WARNINGS/ADVISORIES... Dense Fog Advisory until 9 AM CDT this morning for ILZ056-057- 061>063-066>068-071>073. && $$