Thundersnow12 Posted December 20, 2013 Share Posted December 20, 2013 Moderate to sig hit from OK/TX up through MO, to ORD and up into MI. good improvement. 3-5" most of northern IL with the defo band going through the heart of chi metro. Link to comment Share on other sites More sharing options...
Chicago WX Posted December 20, 2013 Share Posted December 20, 2013 Wagons east. Been an interesting couple of days of modeling, overall. To say the least. Link to comment Share on other sites More sharing options...
MadTown Posted December 20, 2013 Share Posted December 20, 2013 so 3-5" max on this run Link to comment Share on other sites More sharing options...
Chicago Storm Posted December 20, 2013 Author Share Posted December 20, 2013 good improvement. 3-5" most of northern IL with the defo band going through the heart of chi metro. 0.50-0.70"+ QPF across the heart of the CWA. Nice cement event with sub-10:1 ratios. Link to comment Share on other sites More sharing options...
huronicane Posted December 20, 2013 Share Posted December 20, 2013 NAM with a 5-6" lolli over NE IL (looks like Lake/McHenry/Kane/NW Cook, maybe?) Link to comment Share on other sites More sharing options...
gosaints Posted December 20, 2013 Share Posted December 20, 2013 What an entertaining couple days of model runs Link to comment Share on other sites More sharing options...
The_Doctor Posted December 20, 2013 Share Posted December 20, 2013 LOT backed out of the 8 to 10" amounts Link to comment Share on other sites More sharing options...
Hoosier Posted December 20, 2013 Share Posted December 20, 2013 Wagons east. Been an interesting couple of days of modeling, overall. To say the least. Our rain gets colder if this is right. Link to comment Share on other sites More sharing options...
Chicago WX Posted December 20, 2013 Share Posted December 20, 2013 LOT backed out of the 8 to 10" amounts They gonna change those graphics every hour? Geez. Link to comment Share on other sites More sharing options...
Thundersnow12 Posted December 20, 2013 Share Posted December 20, 2013 LOT backed out of the 8 to 10" amounts watch/advisory cancelled? What the helll Link to comment Share on other sites More sharing options...
wisconsinwx Posted December 20, 2013 Share Posted December 20, 2013 Not buying that run. Link to comment Share on other sites More sharing options...
TugHillMatt Posted December 20, 2013 Share Posted December 20, 2013 Well now that the NAM is going east....The 00Z GFS better not go back west! Haha Link to comment Share on other sites More sharing options...
Chicago WX Posted December 20, 2013 Share Posted December 20, 2013 Our rain gets colder if this is right. Indeed. 33 might be have a chance. Link to comment Share on other sites More sharing options...
Chitown Storm Posted December 20, 2013 Share Posted December 20, 2013 watch/advisory cancelled? What the helll that can't be right....unless the original graphic a few hours ago wasn't right. I went from 6-8", down to 1-2" on this map. EDIT: the 8pm update from LOT explains the situation and how the snowfall gradient has been tightened up. However, they note this is a fluid situation subject to further adjustments. Link to comment Share on other sites More sharing options...
Chicago Storm Posted December 20, 2013 Author Share Posted December 20, 2013 LOT... HAVE MADE ADJUSTMENTS TO THE FORECAST GRIDS FOR SATURDAY INTO SUNDAYBASED ON MODEL THERMAL PROFILES AND SOUNDINGS...PARTICULARLY THE1000-850 MB CRITICAL THICKNESS (1300 DM) WHICH IS A KEY INDICATORFOR SNOW VERSUS RAIN/ZR/SLEET. THE GFS RUNS TODAY WERE THE COLDESTWITH THE NAM/ECMWF SHOWING A MUCH MORE DISTINCT WARM NOSE AT 850MB...BUT EVEN THE GFS WOULD ONLY FAVOR THE FAR NORTHERN CWA FOR AWINTRY MIX TRANSITIONING TO SNOW/SLEET AND THEN ALL SNOW ON SATURDAYNIGHT WHERE THERE IS THE BEST OVERLAP WITH FORCING AND LIFT THROUGHTHE DGZ. IN BETWEEN THE FAVORED AREA FOR MORE SIGNIFICANT SNOW/SLEETACCUMS AND MAINLY RAIN OVER THE SOUTHEAST HALF OF THE CWA...HAVEINDICATED A TRANSITION ZONE WHERE A MIXED BAG INCLUDING FREEZINGRAIN IS POSSIBLE. AM CONCERNED THAT IF P-TYPE IS MAINLY ZR FOR ATIME...THERE COULD BE DECENT ICE ACCRETION...AND THIS WOULDINCLUDE PARTS OF THE WEST AND NORTHWEST CHICAGO METRO.FINALLY...SUNDAY MORNING IT APPEARS THAT ALL BUT THE SOUTHEASTTHIRD OF THE CWA WILL TRANSITION OVER TO ALL SNOW AS COLDER AIRPUSHES IN ALOFT.THE TWEAKS TO QPF AND WEATHER TYPES AND SNOW AMOUNT GRIDS RESULTEDIN A MUCH TIGHTER SNOWFALL GRADIENT...WITH POTENTIAL FOR AMOUNTS INEXCESS OF 6 INCHES IN NORTH CENTRAL/NW AND EXTREME NORTHEASTERNILLINOIS...QUICKLY TAPERING TO THE SOUTHEAST. LITTLE OR NO SNOWACCUMULATION IS ANTICIPATED IN THE SOUTHEAST THIRD OF THE CWA.NEEDLESS TO SAY...THIS IS STILL A FLUID SITUATION AND SMALL CHANGESIN THE TRACK OF THE LOW PRESSURE SYSTEM AND THERMAL PROFILES WILLHAVE LARGE IMPLICATIONS IN PRECIPITATION TYPE AND AMOUNTS. HAVE MADENO CHANGES TO THE WINTER STORM WATCH AND FLOOD WATCH IN EFFECT. Link to comment Share on other sites More sharing options...
Stebo Posted December 20, 2013 Share Posted December 20, 2013 Our rain gets colder if this is right. NAM has us here at 33 and rain almost the entire event, although it is completely off on the surface winds which matter because that is what is drawing down the cold air for the event. Nam 2-5kt surface winds mostly out of the east, GFS 10-15kts out of the northeast. Link to comment Share on other sites More sharing options...
Hoosier Posted December 20, 2013 Share Posted December 20, 2013 Kinda bizarre that LOT would make any alterations for a storm 2 days away and before any of the 00z runs finish. Link to comment Share on other sites More sharing options...
Chicago Storm Posted December 20, 2013 Author Share Posted December 20, 2013 watch/advisory cancelled? What the helll The watches are still in effect. Link to comment Share on other sites More sharing options...
huronicane Posted December 20, 2013 Share Posted December 20, 2013 LOT backed out of the 8 to 10" amounts If current trends with the NAM hold (and the GFS maintains its earlier totals) they may need to expand the 4-6" totals. Link to comment Share on other sites More sharing options...
Tim from Springfield (IL) Posted December 20, 2013 Share Posted December 20, 2013 Des Moines hoisted a WSW as well, so here's an updated map of winter storm watches: Unless they're waiting for one more model run and going to issue one early in the morning, IMO I think ILX should have hoisted one tonight for at least the counties west of the Illinois River (including Galesburg, Peoria, Canton). Link to comment Share on other sites More sharing options...
Stebo Posted December 20, 2013 Share Posted December 20, 2013 LOT backed out of the 8 to 10" amounts Never seen a switch so fast before a full model run came in. Link to comment Share on other sites More sharing options...
Stebo Posted December 20, 2013 Share Posted December 20, 2013 Kinda bizarre that LOT would make any alterations for a storm 2 days away and before any of the 00z runs finish. Agreed Link to comment Share on other sites More sharing options...
Thundersnow12 Posted December 20, 2013 Share Posted December 20, 2013 The watches are still in effect. Sarcasm, I know. Don't agree with that move. Link to comment Share on other sites More sharing options...
Chicago WX Posted December 20, 2013 Share Posted December 20, 2013 Kinda bizarre that LOT would make any alterations for a storm 2 days away and before any of the 00z runs finish. Shift change? Remember, I think it was last winter or maybe the previous one to that. Forecaster put up a Watch for Geoslandia...next forecaster came in and ripped apart...and in the end, the first guy got it right. That wasn't such a good chain of events. Link to comment Share on other sites More sharing options...
A-L-E-K Posted December 20, 2013 Share Posted December 20, 2013 LOT just corrected an earlier mistake. No big deal, those things always change and we'll see a dozen more. Link to comment Share on other sites More sharing options...
Harry Perry Posted December 20, 2013 Share Posted December 20, 2013 Agreed +2 Link to comment Share on other sites More sharing options...
The_Doctor Posted December 20, 2013 Share Posted December 20, 2013 LOT just corrected an earlier mistake. No big deal, those things always change Yes, and I'm pretty sure the update came at 813 before the NAM started so it's not like they saw the run and issued the forecast based just off of that. Link to comment Share on other sites More sharing options...
Thundersnow12 Posted December 20, 2013 Share Posted December 20, 2013 That "distinct warm nose" is gone and at/below freezing in the western suburbs by 9z and all snow on both the NAM/GFS. Link to comment Share on other sites More sharing options...
Harry Perry Posted December 20, 2013 Share Posted December 20, 2013 Never seen a switch so fast before a full model run came in. Man, it would suck to be that spot just East of Joliet... Just shows how uncertain/changing this system really is. Link to comment Share on other sites More sharing options...
huronicane Posted December 20, 2013 Share Posted December 20, 2013 That "distinct warm nose" is gone and at/below freezing in the western suburbs by 9z and all snow on both the NAM/GFS. 4k NAM going 4+ inches of snow at DPA through 12z Sunday per the various snow ratio methods in Bufkit, and the warm nose is gone overnight. Link to comment Share on other sites More sharing options...
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