Area Forecast Discussion
Issued by NWS Central Illinois
Issued by NWS Central Illinois
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255 FXUS63 KILX 132024 AFDILX Area Forecast Discussion National Weather Service Lincoln IL 324 PM CDT Mon May 13 2024 .KEY MESSAGES... - A few strong thunderstorms may produce gusty winds and small hail this afternoon/evening. Severe storms are not likely. - Showers and storms are expected (70-90% chance) mainly this afternoon through Tuesday afternoon. Expect generally 0.50 to 1 inch with 10-30% chance of over 1.5 inches. - Another system will bring rain to the area Thursday into Friday, with generally another 0.25 to 0.75 inches of rain. && .DISCUSSION... Issued at 324 PM CDT Mon May 13 2024 The expected upper level low is currently in eastern KS according the latest analysis...but continues to push eastward towards IL. We`ve seen some showers and weak thunderstorms across central IL this afternoon and expect coverage to increase through late afternoon and into the early evening hours. Deep shear remains weak at <20 kts with MLCAPE of 500-1000 J/kg. The latest RAP model has a pocket or two of MLCAPE around 1000 J/kg this afternoon from 4-7 PM when storms will likely be the strongest. A few near-severe storms will be possible with hail close to 1" and/or wind gusts nearing 60 mph, but generally, severe storms are unlikely this afternoon/evening. Showers and perhaps some thunderstorms will be possible through the night as a mid level vort lobe rotates northward around the approaching system. Another lobe rotates north- northwestward tomorrow morning with the low moving from eastern MO into southern IL during the day Tuesday. Expect showers and embedded thunderstorms to continue Tuesday, with the strongest storms south of I-72. With MUCAPE generally around 500 J/kg up to 1000 J/kg and deep share around 20-30 kts, severe potential is limited once again tomorrow. Rainfall will likely be in the 0.5 to 1" range across much of the area, with a 10-30% chance of over 1.5" for the Mon-Tue total. The area sees weak ridging on Wednesday, providing a break from precipitation. However, rain chances return on Thursday and into Friday as the next upper wave moves through the region. Not too excited about severe weather chances with this second system at this time since the NBM has CAPEs at 500 J/kg or less along with 25 kts of deep shear. However, the latest ECMWF is showing some higher CAPEs for Friday, so will need to watch how this one evolves. Generally expecting around 0.5" of rain with this system. Weak ridging in NW flow aloft is expected for Saturday with an upper wave passing to the north on Sunday. We`ll see a surge of warm air ahead of the associated surface low pressure system, bringing highs into the 80s for the weekend. More shower and thunderstorm activity is possible by Sunday with the frontal system and upper support. We`re still too far out to speculate on severe potential with this one. Knutsvig && .AVIATION... (For the 18z TAFs through 18z Tuesday Afternoon) Issued at 1251 PM CDT Mon May 13 2024 Expect shower and thunderstorm coverage to increase across the region today. The best chance for a TS at a terminal appears to be mid afternoon through the early evening hours and have included this thinking in a TEMPO in the TAFs. Thunder chances continue overnight and through 18Z tomorrow, but did not include at this time since they will be hard to time this far out. Still, SHRA chances will exist through much of the period. CIGs fall later tonight through MVFR to IFR along with vis generally in the 3-5 mi range as well. Knutsvig && .ILX WATCHES/WARNINGS/ADVISORIES... None. && $$