Area Forecast Discussion
Issued by NWS Central Illinois
Issued by NWS Central Illinois
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279 FXUS63 KILX 081734 AFDILX Area Forecast Discussion...Updated Aviation National Weather Service Lincoln IL 1134 AM CST Fri Nov 8 2024 .KEY MESSAGES... - Showers and a few thunderstorms will spread across central Illinois Saturday afternoon through early Sunday morning. Rainfall amounts will range from 0.25 to 0.50. - After a period of mild and dry weather Monday and Tuesday, the next significant chance for rain will arrive by next Wednesday. && .UPDATE... Issued at 912 AM CST Fri Nov 8 2024 A thick blanket of cirrus clouds has spread across much of central Illinois this morning...well in advance of a storm system organizing over Texas. While the atmospheric profile is quite dry and no precipitation will occur, satellite trends suggest it will be cloudier today than previously forecast. With only filtered sunshine expected and continued light N/NE winds, think temps will be a couple of degrees cooler as well. Have updated the forecast to go with partly to mostly cloudy wording with afternoon highs similar to yesterday in the upper 50s and lower 60s. Barnes && .DISCUSSION... Issued at 330 AM CST Fri Nov 8 2024 Early morning surface map shows 1028 mb high pressure near Omaha NE and ridging eastward into central IL//IN. This is providing clear skies and light to calm winds over central/se IL and allowing patchy fog to develop past few hours especially from I-70 to the IL river valley. Terre Haute and Taylorville vsby is down to 1/2 mile at 330 am and 2.5 miles at Springfield at 3 am. Patchy shallow ground fog should lift by mid morning (15Z/9 am). Latest CAMs bring high pressure toward Lake Superior by 6 pm and ridging southward into IL and will provide a nice late fall day to central/se IL with north to NW winds less than 10 mph and a fair amount of sunshine with some increasing high/cirrus clouds from the sw later this morning or afternoon. Highs in the lower 60s over much of the area, which is 5-7 degrees above normal highs in the mid 50s central IL and upper 50s southeast IL. High pressure to strengthen to 1032 mb as it drifts eastward into the eastern Great Lakes and southeast Ontario Province by daybreak Saturday and ridging back into WI and ne IL. Models have trended slower with increasing high clouds and also trending a bit cooler with lows tonight especially eastern/ne areas. Lows in the mid to upper 30s in east central IL and around 40F to lower 40s western and sw CWA. A strong 557 dm 500 mb cutoff low over western NM to eject ne and deepen to 548 dm over northeast Nebraska by sunset Saturday, and move into the upper MS river valley and central WI by midday Sunday. Much of CWA should still be dry Sat morning as clouds increase, with slight chance of light rain from Jacksonville sw late Sat morning. Main push of moisture arrives during Sat afternoon/evening, with areas near the Indiana border likely staying dry until early Saturday evening. Isolated thunderstorms possible but severe storms not expected Sat night. Weak instability (20% chance of CAPES at or just above 100 j/kg) arrives in west central IL late Sat afternoon and over much of CWA especially east of the IL river Sat night and se IL early Sunday morning. Highs Sat range from mid to upper 50s west of I-57, coolest from Galesburg to Macomb and Quincy west, and lower 60s in eastern IL with ESE to SE winds 8-16 mph. Rain showers to diminish from the west late Sat night into Sunday morning with a quarter to half inch likely by noon Sunday. Areas near the Wabash river could see a half to three quarter inches. Low pressure lifts into eastern upper MI by sunset Sunday and pushes showers east/ne of CWA Sunday afternoon, with breezy sw winds developing over area and decreasing clouds (clouds lingering longest in southeast IL). Highs Sunday range from around 60F nw of the IL river and mid to upper 60s in southeast IL after relatively mild lows Sat night in the upper 40s/lower 50s. Dry weather returns to the area Sunday night through Tuesday evening with mostly clear skies overall and temps near or a bit above normal with highs in the upper 50s to around 60F. Lows in the lower 40s, except 35-40F on Monday night. Next weather system well off the Pacific Northwest Coast to have low pressure/trof moving into the Midwest on Wednesday and cold front moving into IL Wed afternoon. This will bring next best chance of rain showers around Wednesday into Wed evening with cooler temperatures (actually near normal readings) arriving Thu/Fri behind this system. Highs in the low to mid 50s Thu/Fri with lows in the low to mid 30s Thu night. The Climate Prediction Center (CPC) 6-10 Day Outlook for Nov 13-17 and CPC`s 8-14 Day Outlook for Nov 15-21 both have a 70-80% chance of above normal temperatures over Illinois, and a 35-45% chance of above normal precipitation. 07 && .AVIATION... (For the 18z TAFs through 18z Saturday Afternoon) Issued at 1134 AM CST Fri Nov 8 2024 VFR conditions will prevail through the entire 18z TAF period. BKN-OVC high clouds will persist at the terminals through tonight before forecast soundings indicate ceilings gradually lowering by Saturday morning. NAM soundings suggest ceilings of around 12,000ft after 14z/15z along and west of the I-55 corridor. Several CAMs show low reflectivity values during the morning, perhaps hinting at a few sprinkles. Have opted to leave the TAFs dry at this time, as any very light precip that tries to fall will have a significant amount of dry boundary layer air to overcome before reaching the surface. Winds will initially be N/NW at around 5kt this afternoon, then will back to NE before sunset. As a storm system approaches from the southwest, winds will further back to SE and increase to 10-15kt by mid to late morning Saturday. Barnes && .ILX WATCHES/WARNINGS/ADVISORIES... None. && $$