ILSNOW

Ricky Next item of note is the potential for a period of robust snow showers/squalls on the Arctic front late tonight-early Wednesday. including into Chicago. We wouldn`t be looking at much in the way of accumulation, though snow could fall heavily for a short period and coat paved surfaces, which would be problematic as temperatures plummet through Wednesday morning behind the front. Finally, have higher confidence in advisory criteria westerly winds (45+ mph gusts) for much of if not the entire area through early Wednesday afternoon. For the full forecast package issuance this afternoon, will be considering a Winter Weather Advisory expansion, as well as likely issuing a Wind Advisory for the remaining counties. Castro

Hopefully February will be rockin!!!!!

yep high and dry for the next 10 days we are heading to mid Jan with 1 snow event for entire season.

5 inches here in Buffalo Grove

U r under a winter storm warning for a duster!!!!!

snippets from KLOT Saturday morning, snow appears poised to spread quickly from south to north across much of northern Illinois and far northwestern Indiana and last through the remainder of the day. The steadiest snow looks to remain within a 10-12 hour period from roughly noon Saturday to midnight Sunday, with snow rates of 0.5"/hr prevailing. Heavier snow rates approaching 1"/hr may develop within transient frontogenetical bands as well as along the Illinois shoreline of Lake Michigan where sufficiently cool temperatures will make the marine airmass unstable within a favorable northeasterly wind trajectory. After midnight, snow will taper from west to east except along the Lake Michigan shore where lake enhancement will continue through daybreak Sunday. Snow ratios look to start near 10:1 Saturday afternoon and increase toward 18:1 Saturday night as the low-level temperature profile cools. The highest confidence area for hitting warning-level impacts (e.g. where travel would be discouraged entirely) is actually in Lake County (IL), eastern DuPage County, and all of Cook County where there appears to be an increasing chance that lake-enhanced snow rates of 1"/hr will overlap with blustery northeast winds, leading to low visibility.

Hopefully Ricky will stop by

total precip

look at that cutoff from Arlington Heights to Downtown Chicago ( about 25 miles)

18z Euro

snippets from KLOT An early look at forecast thermal profiles reveals an excellent and deep DGZ with prolific lift, which will encourage fluffy snow ratios of 15:1 or higher. When paired with a strong pressure gradient bolstered by a 1025+ mb high pressure system across the Dakotas, there will be a threat for blustery northeast wind with blowing snow and low visibility within the deformation shield. Interestingly, the 12Z deterministic guidance appears to exhibit excellent agreement showing the track of the low from roughly Tulsa, Oklahoma to Cincinnati, Ohio with the aforementioned band of accumulating snow plastered through the heart of our forecast area. With such a track, cooling 850mb temperatures and northeasterly winds will be more than sufficient for enhancement to snow rates along the Lake Michigan shore with low (if not very low) visibility. Snow would taper overnight into Sunday, with lake effect snow persisting in northwestern Indiana through Sunday afternoon. there does appear to be increasing consistency among all members that the swath of snow will at least touch our forecast area (about 27% of the 51 members drop >6" of snow somewhere in northern Illinois and northwest Indiana). While confidence continues to increase that a winter storm will impact at least part of our area, we continue to urge caution with premature snow forecasts. The message remains that the threat for travel disruptions via air and land on Saturday continues to increase.

comparison 6z NAM vs 12z NAM (Just a slight difference) 12Z NAM

0z CMC weaker and south

0z GFS

18z Euro 90 hours some big changes

Nice closeup

fantasy 18z 84hr NAM

12z Euro 24 hour storm totals

URGENT - WINTER WEATHER MESSAGE National Weather Service Chicago IL 203 PM CST Mon Dec 27 2021 ILZ003>006-008-010>013-103-104-280415- /O.NEW.KLOT.WW.Y.0013.211228T1500Z-211229T0000Z/ Winnebago-Boone-McHenry-Lake IL-Ogle-Lee-De Kalb-Kane-DuPage- Northern Cook-Central Cook- Including the cities of Rockford, Belvidere, Crystal Lake, Algonquin, McHenry, Woodstock, Waukegan, Buffalo Grove, Mundelein, Gurnee, Rochelle, Oregon, Byron, Dixon, DeKalb, Sycamore, Aurora, Elgin, Naperville, Wheaton, Downers Grove, Lombard, Carol Stream, Evanston, Des Plaines, Schaumburg, Palatine, Northbrook, Chicago, Cicero, Oak Lawn, Oak Park, and La Grange 203 PM CST Mon Dec 27 2021 ...WINTER WEATHER ADVISORY IN EFFECT FROM 9 AM TO 6 PM CST TUESDAY... * WHAT...Slippery travel conditions due to steady snow expected. * WHERE...Portions of north central and northeast Illinois. * WHEN...From 9 AM to 6 PM CST Tuesday. * IMPACTS...Plan on slippery road conditions. * ADDITIONAL DETAILS...The peak snow rates of up to one half inch per hour are expected between noon and 3 pm CST. Snow totals are expected to range from 1 to 3 inches by the time snow ends.

KLOT AVIATION... For the 18Z TAFs... Upper-level clouds will thicken toward daybreak Tuesday as a storm system approaches from the southwest. Precipitation will arrive at the terminals between 17 and 18Z and continue through 21 to 22Z. Confidence is increasing that the predominant precipitation type may end up as steady snow, especially at RFD/DPA/ORD/MDW, with steady temperatures prevailing near the freezing mark. After collaboration with CWSU ZAU, the outgoing TAF package will feature TEMPO groups for visibility and ceiling drops to 3/4SM and 300 feet, respectively, at ORD and MDW between 18-21Z. Should snow end up steady enough, visibility may actually drop as low as 1/2SM. Elsewhere, targeted TEMPO groups may be introduced with the 00Z TAF package. After 21Z, the snow is expected to transition to light rain showers or drizzle as temperatures warm above freezing, though ceilings should remain at or below 500 feet. Winds are expected to be out of the southeast through the precipitation event. Confidence is medium in the forecast for precipitation type and associated reduced visibilities and ceilings. Borchardt