Area Forecast Discussion
Issued by NWS Central Illinois
Issued by NWS Central Illinois
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769 FXUS63 KILX 312302 AFDILX Area Forecast Discussion...Updated Aviation National Weather Service Lincoln IL 602 PM CDT Fri May 31 2024 .KEY MESSAGES... - Widespread showers and storms arrive late tonight with chances continuing through Saturday. Rainfall amounts look to range from 0.5 to 1 inch, with a 20-30% chance for amounts exceeding 1 inch. - Additional chances for showers and storms are expected early next week, including the threat for some severe storms. && .DISCUSSION... Issued at 309 PM CDT Fri May 31 2024 Another pleasant and seasonable weather day is occurring across the state this afternoon as we remain largely under high pressure. Cloud cover has increased some since this morning as an upper wave over the central Plains approaches from the southwest. Moisture transport will increase ahead of the wave and eat away at mid-level dry air, eventually leading to shower activity late tonight continuing into Saturday. Lack of both instability and a pronounced upper jet will prevent severe weather, however CAPE of a ~500 J/kg give or take will support scattered thunderstorm activity. Precipitation totals look to range from 0.5 to 1 inch areawide, though slightly higher amounts over 1 inch will be possible with any thunderstorms. The NBM highlights about a 20-30% chance of 1+ inch of rainfall. Brief upper ridging will overspread the area going into the second half of the weekend, putting an end to precipitation for Sunday. Flow aloft becomes more zonal by the beginning of the new week, allowing a series of upper waves to rotate through the area. Periods of showers and storms become common Monday, looking to continue through at least Midweek. A stronger wave will track from the Pacific Northwest into the northern Plains/Canadian Prairies later Monday into Tuesday, bringing what looks like a more active period for the central US. At this point, the better jet dynamics look to remain positioned to our west and northwest until later in the week, which would imply less supportive wind shear. The CSU-MLP highlights a few days with a 5-15% chance for severe weather next week, with the highest probability being on Tuesday which is when a cold front will approach from the west. Temperatures will warm back near or slightly above normal for early next week with dewpoints in the 60s to low 70s leading to a more humid airmass. The Climate Prediction Center then favors below normal temperatures for the end of next week into next weekend as the early week system becomes occluded north of the Great Lakes Region and pushes lower mid-level heights southward into the region. NMA && .AVIATION... (For the 00z TAFs through 00z Saturday Evening) Issued at 602 PM CDT Fri May 31 2024 SHRA will advance northeast across central IL late tonight, and continue off and on though Saturday afternoon. A few TSRA are possible (20% chance) mainly Saturday afternoon but coverage too low to include in TAFs. Ceilings and visibilities will drop to MVFR with the rain, with transient periods of IFR ceilings in heavier showers. After wind gusts diminish over the next hour or two, southeast winds near 10 kt will persist through the forecast. 25 && .ILX WATCHES/WARNINGS/ADVISORIES... None. && $$