212 FXUS63 KILX 232332 AFDILX Area Forecast Discussion National Weather Service Lincoln IL 632 PM CDT Tue Apr 23 2019 .SHORT TERM...(This evening through Wednesday) ISSUED AT 253 PM CDT Tue Apr 23 2019 Early this afternoon, a cold front continues to sag south across southern Illinois and Indiana towards the Ohio River Valley. In its wake, most of central Illinois has been blanketed in low stratus and cooler temperatures. While there has been steady clearing of low clouds from the north today, high clouds have been overspreading the area from the southwest. There may be a few peaks of sun, especially near and north of the I-74 corridor late this afternoon or early evening, and partly cloudy conditions will continue south of I-70. The remainder of the area should remain cloudy the rest of today and tonight. Meanwhile, surface low is analyzed over the far southwest corner of Missouri this afternoon and is progged to lift northeast to along the I-70 corridor in the southern CWA late Wednesday evening. Frontal boundary will begin to shift north again Wednesday. Low to mid 60s are favored north of the front/I-70 corridor Wednesday afternoon, while mid to upper 70s are expected south. Precip chances will increase in response to low/mid level isentropic ascent overspreading portions of the area. The highest PoPs are located along and south of the I-72 corridor Wednesday. Modest MUCAPE of 200-500 J/kg will be in place near the warm front allowing for the possibility of a few thunderstorms as well. .LONG TERM...(Wednesday night through Tuesday) ISSUED AT 253 PM CDT Tue Apr 23 2019 Area of low pressure will shift east of the region Wednesday night with precip chances at least briefly diminishing early on Thursday behind the low. Attention turns back to the northwest as a northern stream shortwave trough is the progged to dig across portions of the Upper Midwest and Midwest later Thursday with attendant surface trough making its way across the forecast area Thursday afternoon and evening. Weak diurnal instability and modest forcing associated with the upper wave may support a few scattered showers, but the bulk of the day should be dry with afternoon highs in the lower 70s. Northwest flow will bring drier and slightly cooler conditions on Friday with highs generally in the mid to upper 60s. A dynamic system is poised to sweep across the region this weekend bringing widespread showers along with a chance for thunderstorms Saturday. Moisture overall is expected to remain on the more modest side, though both the GFS and ECMWF pool upper 50s to low 60s dew points immediately along the front. There remain small but important timing and track differences between the models which make pinning down convective details difficult. Strong mid level flow over the region will result in a high shear environment; however, instability is expected to remain confined to within a narrow corridor near the cold front. The GFS runs slightly faster than the ECMWF and brings the front into the forecast area late afternoon/early evening, but still during a favorable diurnal time frame. The slower ECMWF, meanwhile comes in slower and misses this window and the more southerly low track would not be as favorable for surface based instability over much if any of the area. If the faster timing were to verify, the high shear/low CAPE environment could pose at least a conditional risk for severe weather, so will need to keep a close eye on trends in the coming days to see if ingredients can come together. Temperatures briefly turn cooler again behind the low on Sunday with breezy north winds possible before high pressure translates east across the region later in the day. Baroclinic zone is progged to inch back northward setting up over portions of the Midwest and resulting in a potentially active period of weather. early through the middle of next week. && .AVIATION...(For the 00Z TAFS through 00Z Wednesday evening) Issued at 632 PM CDT Tue Apr 23 2019 Central Illinois terminal all MVFR this evening as stalled boundary across southern Illinois continues to push abundant cloud cover into the area. The northern edge of clouds is oscillating as waves moving along the front provide pockets of enhanced lift and then move by. Followed LAMP closely which suggestd we may have a brief period of VFR late tonight before the next wave approaches. This stronger wave will likely push the boundary northward ahead of it and bring a significant possibility of rain to the terminals by mid-morning at southern terminals and early afternoon at I-74 sites. CIGs should fall as precip moves in and may drop to IFR at KSPI and KDEC as they remain just north of the front. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...Deubelbeiss LONG TERM...Deubelbeiss AVIATION...Barker