386 FXUS63 KILX 211153 AFDILX Area Forecast Discussion National Weather Service Lincoln IL 553 AM CST Tue Feb 21 2017 .SHORT TERM...(Today and tonight) ISSUED AT 324 AM CST Tue Feb 21 2017 Slow-moving cold front continues to edge eastward early this morning...with latest surface analysis placing it along the Mississippi River. Light to moderate showers are occurring along/ahead of the boundary, primarily impacting locations along and west of the I-55 corridor. Showers will gradually spread eastward across the remainder of the area, but may not reach the Indiana border until mid-morning. The front will tend to dissipate as it tracks further east, so am expecting areal coverage of showers to decrease as the day progresses. Temperature forecast will be a bit tricky today, as cloud cover and showers will keep readings down across the E/SE KILX CWA. With clearing expected to take place across the west this afternoon, think warmest highs in the upper 60s to around 70 will occur along/west of I-55. Further east where overcast conditions will persist through the entire day, highs will only reach the lower to middle 60s. Front will sag into the Ohio River Valley and wash out tonight, allowing skies to become mostly clear across all but the far SE where partial cloud cover will linger. With clearing skies, light winds, and a very moist boundary layer in place...think fog will develop overnight. Fog should become thickest/most widespread where afternoon mixing will be the least...generally across the eastern two-thirds of the CWA. .LONG TERM...(Wednesday through Monday) ISSUED AT 324 AM CST Tue Feb 21 2017 Fog will gradually dissipate Wednesday morning, with mostly sunny skies expected by afternoon. Given abundant sunshine and increasing southwesterly winds ahead of an approaching boundary, record high temperatures appear to be a good bet. Thermal ridge will be in place across the region...with 850mb temps increasing to 12-14C. As a result, am expecting afternoon highs to top out in the lower to middle 70s. Front will drop southward into central Illinois Wednesday night, eventually stalling near the I-72 corridor. A distinct north-south temperature gradient will develop on Thursday...with highs ranging from the upper 50s far north around Galesburg and Lacon...to the lower 70s south of I-70. Much of the day should be dry: however, as synoptic lift increases along the boundary in advance of a potent short-wave ejecting out of the Rockies, scattered showers will develop during the afternoon. Low pressure is still expected to develop in the lee of the Rockies Thursday evening, then track into the southern Great Lakes by Friday evening. Minor model discrepancies are still present: however, consensus shows a strong cold front bisecting central Illinois by 18z Fri. Given unseasonably warm/moist southerly flow ahead of the front, the atmosphere will become moderately unstable across east- central and southeast Illinois...with GFS indicating MUCAPE values of around 1000J/kg. In addition...0-6km bulk shear values will increase to 55-65kt as a powerful mid-level jet approaches from the west. Think strong to potentially severe thunderstorms will develop along/ahead of the front Friday afternoon, mainly along and east of I-57 where likely PoPs are warranted. Any storms that fire will quickly shift into Indiana by early evening, followed by breezy and sharply colder conditions. Models continue to suggest wrap-around moisture will brush the N/NW CWA late Friday night into Saturday morning. With temperatures falling into the upper 20s and lower 30s, a period of light snow will be likely...with some minor accumulations possible along and north of a Canton to Danville line by Saturday morning. Cool/more typical mid-February weather will prevail over the weekend...with highs in the upper 30s and lower 40s on Saturday rising into the 40s everywhere by Sunday. The return to normal will be short-lived however, as zonal flow will allow temps to warm significantly by early next week. Unfortunately the warming trend will also be accompanied by precipitation. At this time it appears a brief period of light snow will be possible Monday morning before temps warm sufficiently for all rain Monday afternoon into Tuesday. && .AVIATION...(For the 12Z TAFS through 12Z Wednesday morning) Issued at 552 AM CST Tue Feb 21 2017 A cold front will gradually push across central Illinois today, with variable wind directions for much of the day, as wind speeds remain less than 10 kt. A band of rain showers will advance eastward ahead of the front, with rainfall coming to an end from west to east through the day. Dry conditions should develop at all TAF sites by early afternoon. As rain comes to an end this morning, PIA and SPI could see VIS and CIGs dip to IFR or even LIFR for a brief period. HRRR and RAP forecasts show narrow channels of low clouds and low vis that could advance eastward slightly into PIA and SPI areas. Have included a tempo at PIA for 3/4sm BR for now, and will monitor progression of low vis/cigs. The latest guidance is now showing winds becoming mainly easterly in the vicinity of the front, as it rotates into a west-east orientation as it drops into Illinois. There is low confidence in the wind direction progression over the next 12 hours, but wind speeds should remain 8 kt or less. Locally dense fog could affect eastern Illinois later tonight, due to light winds and residual ground level moisture. DEC and CMI will have the higher potential of VLIFR fog after 09z. && .CLIMATE... Issued at 312 PM CST Sun Feb 19 2017 Record Highs / Record Warm Lows - Tuesday Feb 21st... Peoria........ 69 / 46 Lincoln....... 69 / 45 Springfield... 69 / 48 Champaign..... 67 / 47 Bloomington... 69 / 46 Decatur....... 68 / 48 Danville...... 67 / 50 Galesburg..... 68 / 40 Charleston.... 71 / 52 Effingham..... 73 / 52 Record Highs / Record Warm Lows - Wednesday Feb 22nd... Peoria........ 71 / 51 Lincoln....... 71 / 52 Springfield... 71 / 53 Champaign..... 69 / 49 Bloomington... 70 / 53 Decatur....... 72 / 51 Danville...... 71 / 54 Galesburg..... 61 / 45 Charleston.... 71 / 52 Effingham..... 74 / 55 && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...Barnes LONG TERM...Barnes AVIATION...Shimon CLIMATE...07