Area Forecast Discussion
Issued by NWS Central Illinois
Issued by NWS Central Illinois
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922 FXUS63 KILX 111738 AFDILX Area Forecast Discussion...Updated Aviation National Weather Service Lincoln IL 1238 PM CDT Sat May 11 2024 .KEY MESSAGES... - The weekend is panning out to be dry and pleasant with increasing warmth through Sunday. - Soaking rains and a few storms return on Monday and linger through Tuesday. There remains a 40-60% chance that rainfall totals will reach around one inch during that time, which could send a few rivers toward bank full. && .UPDATE... Issued at 1023 AM CDT Sat May 11 2024 At 10:15am, visible satellite showed clear skies across central Illinois, which has resulted in a rapid rise in temps this morning favoring highs a smidgen warmer than previously forecast; that was updated using the latest iteration of the HRRR which seems to be handling mixing/insolation well. The wind forecast was nudged up a hair also, given ASOS observations show gusts already approaching/reaching 30 mph and BUFKIT soundings suggest mixing will only deepen (though winds aloft will simultaneously weaken) through early afternoon when top of mixed layer (800-750mb, per NAM and GFS forecast soundings) winds are in the 35-40mph range. We`ll likely have frequent northwesterly gusts around 25-33 mph this afternoon, making the airmass feel a little chillier than temps alone would suggest. Bumgardner && .DISCUSSION... Issued at 234 AM CDT Sat May 11 2024 The latest IR satellite images show a band of mid clouds drifting south through Illinois as a cold front traverses the area. The aurora was still visible through the clouds, as an impressive G5 solar storm impacts the CONUS. As for precip along the cold front, showers have been spotty to say the least with the dry airmass limiting any measurable rain in most of the area. Those showers should depart into Indiana by sunrise or shortly after, with nearly full sunshine this morning. Deep mixing will dry out the air today, as surface dewpoints dip into the lower 40s. However, afternoon cumulus will redevelop due to steeper low level lapse rates in the post-cold frontal airmass. Northwest wind gusts will top out in the 25 to 30 mph range early this afternoon, adding a cooler feel to this below normal temperature day. Southerly return flow on Sunday will help boost high temps into the low 80s west of I-55, with upper 70s east of I-55. Surface dewpoints will make a return to the 50s, in preps for the onset of the next wave of rain early Monday morning. Surface cyclogenesis will develop over the central Plains as a cold front makes southward push from the upper Midwest toward the Ohio River Valley. The two will intersect as the low reaches southern Illinois late Monday night into Tuesday, setting the stage for wetting rains much of the day and night Monday. QPF totals in that 24 hour period look to climb over 0.75" in most of central IL (70% chance). Instability params are marginal for thunder for most of the day Monday, but increase Monday night into Tuesday as frontal convergence increases and mid-level lapse rates steepen. Severe weather potential appears low amid weaker shear profiles, and a triple point that passes well to the south of IL. Our coolest day of the next week will be Tuesday, as highs remain in the 60s north of I-70 (70-80% chance per DESI Grand Ensemble). The break in the rain Wednesday will be short-lived as the next frontal system progresses through the mid-Mississippi River Valley area Thursday and Friday. Rain and storm chances late week will keep the recent wet trends in full swing. Shimon && .AVIATION... (For the 18z TAFs through 18z Sunday Afternoon) Issued at 1233 PM CDT Sat May 11 2024 VFR conditions will continue through the forecast period, with diurnal cumulus, along with northwest winds gusting to 25 kt, diminishing after sunset this evening. Tomorrow, low level winds will turn to southerly, gusting 15-20 kt near the end of the forecast period. Bumgardner && .ILX WATCHES/WARNINGS/ADVISORIES... None. && $$