msp Posted December 20, 2010 Share Posted December 20, 2010 great 25dbz band of moderate snow streaked across the southwest metro right now. i haven't taken a measurement, but we're probably close to half an inch. Link to comment Share on other sites More sharing options...
Hoosier Posted December 20, 2010 Share Posted December 20, 2010 850's at ORD are -4C at 12Z. The event is over by then. There will be no mixing during the main event. Freezing drizzle or snow grains after the snow is done due to drying above 800mb is possible, but a bonafide mixing scenario is not going to happen. Using 1000-500mb thicknesses in this situation is tricky, as mid-level thicknesses are pretty high due to WAA aloft, but never get that close to... or over 0C. That's what I said the other day...do not use the 540 line for this event (never should rely on that anyway). It's going to be misleading given the deep layer of sufficiently cold but not very cold temps in the column. Link to comment Share on other sites More sharing options...
baroclinic_instability Posted December 20, 2010 Author Share Posted December 20, 2010 AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE QUAD CITIES IA IL 1019 AM CST MON DEC 20 2010 UPDATE ..MAJOR REVISIONS TO THE OVERALL FCST 12Z UA DATA COMBINED WITH RADAR/SFC OBS SHOW THE SNOW BREAKING OUT MUCH SOONER THAN EXPECTED. COMBINATION OF RUC TRENDS AND INCOMING WRF INDICATE THE 290K CONDENSATION PRESSURE DEFICITS AND 290K OMEGA DEPICT REASONABLY WELL WHAT IS CURRENTLY GOING. WAA STRENGTHENS THE OMEGA BY LATE MORNING AND INTO THE AFTERNOON. THE STRONGEST FORCING IS CURRENTLY ROUGHLY ON A KALO TO KEWANEE LINE AND WILL SLOWLY SHIFT TO THE NORTH/EAST. THUS HAVE EXPANDED THE CURRENTLY HEADLINES AND HAVE MADE THEM EFFECTIVE IMMEDIATELY. IT APPEARS THAT 2 TO NEARLY 4 INCHES MAY OCCUR BY SUNSET WITH ANOTHER INCH OR TWO POSSIBLE OVERNIGHT. FCST SOUNDINGS IN THE SOUTH GET TO AROUND FREEZING SO A RASN MIX IS POSSIBLE IN THE SOUTHERN THIRD OR SO OF THE CWFA. One of the "surprises" I was potentially talking about. These things always have a few. Interested to see how much this area eventually sees with current trends. Link to comment Share on other sites More sharing options...
Hoosier Posted December 20, 2010 Share Posted December 20, 2010 Some nice banding showing up on ILX's radar. Looks like it could be a good relatively short duration thump here this early evening. Yep, I'm still thinking we can manage 2-3" Link to comment Share on other sites More sharing options...
baroclinic_instability Posted December 20, 2010 Author Share Posted December 20, 2010 Transverse banding on vis over southern MN, typical with an active meso jet circulation and strong divergence. Good stuff. Link to comment Share on other sites More sharing options...
Chicago WX Posted December 20, 2010 Share Posted December 20, 2010 QC report from DVN. 1215 PM SNOW DAVENPORT MUNICIPAL AIR 41.62N 90.58W 12/20/2010 M3.2 INCH SCOTT IA OFFICIAL NWS OBS 6-HR STORM TOTAL...STILL SNOWING. Link to comment Share on other sites More sharing options...
A-L-E-K Posted December 20, 2010 Share Posted December 20, 2010 really nice area of 35 dbz returns out there, someone just north of the QC should go over 4" Link to comment Share on other sites More sharing options...
Chicago Storm Posted December 20, 2010 Share Posted December 20, 2010 5" might be a stretch but given the banding already going on I can see some areas getting that. should begin here in a few hours. That was an area wide call, not just MBY. Link to comment Share on other sites More sharing options...
Chicago Storm Posted December 20, 2010 Share Posted December 20, 2010 Link to comment Share on other sites More sharing options...
Chicago Storm Posted December 20, 2010 Share Posted December 20, 2010 NMM and ARW Link to comment Share on other sites More sharing options...
A-L-E-K Posted December 20, 2010 Share Posted December 20, 2010 NMM and ARW those hi-res runs and current radar trends indicate LOTs little graphic might be flip flopped Link to comment Share on other sites More sharing options...
janetjanet998 Posted December 20, 2010 Share Posted December 20, 2010 the snow ended here about 1/2 hour ago well before the radar showed the echoes moving NE away from me(radar finally showing no echoes over ne NOW) The band of snow is set up EXACTLY where it was during the first "super clipper" a few weeks ago Link to comment Share on other sites More sharing options...
A-L-E-K Posted December 20, 2010 Share Posted December 20, 2010 the snow ended here about 1/2 hour ago well before the radar showed the echoes moving NE away from me(radar finally showing no echoes over ne NOW) The thein f snow s set up EXCACTLY where it was during the first "super clipper" a few weeks ago yep, incredibly similar placement, will be interesting to see if Champaign out does Chicago again. Band really streaking south but hardly moving east. Link to comment Share on other sites More sharing options...
msp Posted December 20, 2010 Share Posted December 20, 2010 mpx just added a whole string of counties in their south and southwest to the warning. also added heavy snow wording to forecasts here int he metro. Link to comment Share on other sites More sharing options...
mnchaser Posted December 20, 2010 Share Posted December 20, 2010 Just over 3 inches here, Snowing so hard it looks like pouring rain. Heaviest banding about to move in here soon. Link to comment Share on other sites More sharing options...
msp Posted December 20, 2010 Share Posted December 20, 2010 impressive totals already in southern MN: 4.5 st. james 6.5 madelia still snowing heavily at both those sites (neither is in the warning area) Link to comment Share on other sites More sharing options...
A-L-E-K Posted December 20, 2010 Share Posted December 20, 2010 heavy banding def setting up futher south than thought. Wonder how long it takes LOT to adjust things for their SW area. Last HRRR run was awful, much too far north. Link to comment Share on other sites More sharing options...
janetjanet998 Posted December 20, 2010 Share Posted December 20, 2010 heavy banding def setting up futher south than thought. Wonder how long it takes LOT to adjust things for their SW area. this is sort of comical..(not blaming NWS for tough forecast) my orginal forecast at 4am was flurries in the morning a chance of snow in the afternoon and into tonight befire changing to ZR- up to an inch.. now they just updated and said 1-2 inches possible today with snow,,,,but now the snow looks over Link to comment Share on other sites More sharing options...
A-L-E-K Posted December 20, 2010 Share Posted December 20, 2010 How does Dubuque always find it's way into the SN band? Link to comment Share on other sites More sharing options...
baroclinic_instability Posted December 20, 2010 Author Share Posted December 20, 2010 this is sort of comical..(not blaming NWS for tough forecast) my orginal forecast at 4am was flurries in the morning a chance of snow in the afternoon and into tonight befire changing to ZR- up to an inch.. now they just updated and said 1-2 inches possible today with snow,,,,but now the snow looks over Is that the discussion or was that a pt/click forecast? The NWS system is not made too well for rapid updating in the grids though either way...sometimes when they try and quickly update based off current trends things like this happen. Link to comment Share on other sites More sharing options...
A-L-E-K Posted December 20, 2010 Share Posted December 20, 2010 Trends looking really good for Sterling and DeKalb, should see a prolonged period of moderate snow. Anyone else think the west and south portion of this map is going to bust? Link to comment Share on other sites More sharing options...
baroclinic_instability Posted December 20, 2010 Author Share Posted December 20, 2010 Someone already said it, but the early heavy band pushing east through eastern IA and into ILL looks eerily similar to super clipper. Link to comment Share on other sites More sharing options...
janetjanet998 Posted December 20, 2010 Share Posted December 20, 2010 Is that the discussion or was that a pt/click forecast? The NWS system is not made too well for rapid updating in the grids though either way...sometimes when they try and quickly update based off current trends things like this happen. so to sum up the forecast people heard today was scattered flurries in the morning, then a 50% chance of light snow in the afternoon and evening up to one inch... what happened (unless trends change) 1 to 1.5 inches(est. just north of here) inch or so before noon or 2pm in not so light snow at times,,, then its over.. discussion early this am SHORT TERM...TODAY THROUGH WEDNESDAY... PRECIPITATION CURRENTLY OVER IOWA EXPECTED TO ENHANCE AND EXPAND SOUTHEAST INTO NORTHERN AND EASTERN ILLINOIS TODAY...AS LIFT INCREASES ALONG THE BAROCLINIC ZONE. QUITE A BIT OF DRY AIR AT THE LOWER LEVELS NEEDS TO SATURATE...SO WILL CONTINUE WITH THE 40 PERCENT POPS FOR THIS AFTERNOON ACROSS THE NORTH AND NORTHEAST... WITH MAINLY FLURRIES ELSEWHERE. HEAVIEST SNOW AXIS CONTINUES TO REMAIN TO OUR NORTH...BUT MAY STILL SEE A HALF INCH OR SO ACROSS THE NORTHEAST EDGE OF THE CWA THROUGH THIS EVENING. MOST MODELS NOW SHOWING THE DOUBLE-BARREL STRUCTURE OF THE INCOMING STORM SYSTEM TONIGHT...WITH THE NORTHERN LOW THE MORE DOMINANT AS AN UPPER CLOSED LOW IS NEARBY. UNFORTUNATELY THERE IS STILL NOT MUCH AGREEMENT AS TO THE STRENGTH OF THIS LOW...BUT THEY AGREE THE PRECIPITATION THREAT SHOULD TAPER FROM SOUTH TO NORTH OVERNIGHT. FORECAST SOUNDINGS SHOW NO ICE CRYSTALS LEFT AFTER MIDNIGHT...SO SHOULD SEE MORE OF A DRIZZLE OR FREEZING DRIZZLE SITUATION BY LATE IN THE NIGHT 10:30 am discussion DISCUSSION ISSUED 1035 AM CST MON DEC 20 2010 SNOW HAS SHIFTED INTO THE FORECAST AREA QUITE A BIT FASTER THAN EARLIER THOUGHT. BASED ON THE RADAR TRENDS...IT APPEARS THE SNOW BAND OUT TO OUR WEST WAS SHIFTING MORE NORTHEAST AND SETTING UP ACRS OUR FAR NORTH AND NORTHEAST...NORTH OF INTERSTATE 74. HAVE INCREASED THE POPS FOR THIS MRNG AND AFTN IN THOSE AREAS BASED ON CURRENT TRENDS WITH RADAR AND SATELLITE DATA. WITH A FASTER TIMING ON THE ONSET OF THE PRECIP INTO OUR AREA TODAY...WOULD THINK THE SNOW SHOULD SHIFT JUST OFF TO OUR EAST AND NORTH AT A FASTER PACE AS WELL AND WILL ADJUST THE POPS FOR TONIGHT BASED ON THE LATEST FORECAST SOUNDINGS...WHICH SUGGEST MOST OF OUR AREA WILL LOSE THE ICE CRYSTALS...INDICATING THE POTENTIAL FOR DRIZZLE OR FREEZING DRIZZLE. THAT THREAT SHOULD CONTINUE INTO TUE MRNG. MAY NEED A HEADLINE ACRS OUR NE TO ADDRESS THE THREAT FOR SOME LIGHT ICING OVERNIGHT...BUT WILL ADDRESS THAT IN THE AFTN PACKAGE. UPDATE SHOULD BE OUT SHORTLY. SMITH 3:30 Zone INCLUDING THE CITIES OF...PEORIA 338 AM CST MON DEC 20 2010 TODAY...CLOUDY. SCATTERED FLURRIES IN THE MORNING THEN A 50 PERCENT CHANCE OF SNOW IN THE AFTERNOON. HIGHS IN THE LOWER 30S. SOUTHEAST WINDS 10 TO 15 MPH WITH GUSTS TO AROUND 25 MPH. TONIGHT...SNOW LIKELY IN THE EVENING THEN A CHANCE OF FREEZING RAIN OR SNOW AFTER MIDNIGHT. SNOW ACCUMULATION UP TO 1 INCH. NOT AS COLD. NEAR STEADY TEMPERATURE AROUND 30. SOUTHEAST WINDS 10 TO 15 MPH. CHANCE OF PRECIPITATION 70 PERCENT. 8 AM UPDATE INCLUDING THE CITIES OF...PEORIA 804 AM CST MON DEC 20 2010 TODAY CLOUDY WITH A 50 PERCENT CHANCE OF SNOW. HIGHS IN THE LOWER 30S. SOUTHEAST WINDS 10 TO 15 MPH. GUSTS UP TO 25 MPH IN THE AFTERNOON. TONIGHT...SNOW LIKELY IN THE EVENING THEN A CHANCE OF FREEZING RAIN...SNOW AND AREAS OF FREEZING DRIZZLE AFTER MIDNIGHT. SNOW ACCUMULATION UP TO 1 INCH. NOT AS COLD. NEAR STEADY TEMPERATURE AROUND 30. SOUTHEAST WINDS 10 TO 15 MPH. CHANCE OF PRECIPITATION 70 PERCENT. TUESDAY 11 AM UPDATE INCLUDING THE CITIES OF...PEORIA 1056 AM CST MON DEC 20 2010 REST OF TODAY OCCASIONAL SNOW. NEW SNOW ACCUMULATION AROUND 1 INCH. HIGHS IN THE LOWER 30S. SOUTHEAST WINDS 10 TO 15 MPH. GUSTS UP TO 25 MPH IN THE AFTERNOON. CHANCE OF PRECIPITATION 90 PERCENT. TONIGHT CLOUDY. CHANCE OF SNOW OR PATCHY FREEZING DRIZZLE IN THE EVENING...THEN PATCHY FREEZING DRIZZLE AFTER MIDNIGHT. NOT AS COLD. NEAR STEADY TEMPERATURE AROUND 30. SOUTHEAST WINDS 10 TO 15 MPH. CHANCE OF PRECIPITATION 40 PERCENT. 1 PM UPDATE SNOW STOPPED JUST BWFORE ISSUED INCLUDING THE CITIES OF...PEORIA 1255 PM CST MON DEC 20 2010 REST OF TODAY SNOW. SNOW ACCUMULATION OF 1 TO 2 INCHES. NEAR STEADY TEMPERATURE IN THE LOWER 30S. SOUTHEAST WINDS 10 TO 15 MPH WITH GUSTS TO AROUND 25 MPH. CHANCE OF PRECIPITATION 90 PERCENT. TONIGHT CLOUDY. CHANCE OF SNOW OR PATCHY FREEZING DRIZZLE IN THE EVENING...THEN PATCHY FREEZING DRIZZLE AFTER MIDNIGHT. NOT AS COLD. NEAR STEADY TEMPERATURE AROUND 30. SOUTHEAST WINDS 10 TO 15 MPH. CHANCE OF PRECIPITATION 40 PERCENT. Link to comment Share on other sites More sharing options...
Chicago Storm Posted December 20, 2010 Share Posted December 20, 2010 Trends looking really good for Sterling and DeKalb, should see a prolonged period of moderate snow. Anyone else think the west and south portion of this map is going to bust? Should be 2-4" area wide. Link to comment Share on other sites More sharing options...
Chicago WX Posted December 20, 2010 Share Posted December 20, 2010 Band in central IL almost looks stationary around Champaign. Meanwhile just off to the east, sun trying its hardest to poke through the overcast here. Link to comment Share on other sites More sharing options...
msp Posted December 20, 2010 Share Posted December 20, 2010 now at 3-7 & 1-2 here, with snow mostly ending by 9pm. i'd say moderate snow right now. have to try to drive over to chanhassen here shortly. we'll see how the plows are keeping up. Link to comment Share on other sites More sharing options...
Hoosier Posted December 20, 2010 Share Posted December 20, 2010 Band in central IL almost looks stationary around Champaign. Meanwhile just off to the east, sun trying its hardest to poke through the overcast here. Not for long Link to comment Share on other sites More sharing options...
janetjanet998 Posted December 20, 2010 Share Posted December 20, 2010 close to SN+ in Lacon IL KC75 201925Z AUTO 11005KT 1/4SM SN OVC002 M02/M03 A3003 Link to comment Share on other sites More sharing options...
Chicago WX Posted December 20, 2010 Share Posted December 20, 2010 Not for long True enough. A few specks of 35DBZ showing up on the ILX radar just north of Bloomington. Link to comment Share on other sites More sharing options...
MN Transplant Posted December 20, 2010 Share Posted December 20, 2010 impressive totals already in southern MN: 4.5 st. james 6.5 madelia still snowing heavily at both those sites (neither is in the warning area) Looks like some nice fat dendrites on the skycam from Mankato in that band. Link to comment Share on other sites More sharing options...
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