baroclinic_instability Posted December 29, 2011 Share Posted December 29, 2011 Might as well start a thread since this will likely be some of the more interesting weather across the plains in quite a while. Guidance has been strongly suggestive of a strong Pacific wave amplifying across the CONUS as it interacts with the PV across Canada. Much of the amplification of this wave will actually be due to the intensity of the ejecting IPV anomaly as the phase interaction with the PV doesn't seem to occur until after this system has progressed well into the Lakes/OV. Given the latest guidance, the big news with this storm will be winds across portions of the plains as well as a localized winter advisory type event across MN. What makes the winter aspect interesting is the wind potential combined with the snow across parts of MN. Link to comment Share on other sites More sharing options...
JoMo Posted December 29, 2011 Share Posted December 29, 2011 This just shows you how terrible winter has been so far. Link to comment Share on other sites More sharing options...
baroclinic_instability Posted December 29, 2011 Author Share Posted December 29, 2011 This just shows you how terrible winter has been so far. Haha I know, but it does look to be an exciting storm to track, especially with the wind potential. Has the hallmarks of an epic wind producer across the high plains. Link to comment Share on other sites More sharing options...
baroclinic_instability Posted December 30, 2011 Author Share Posted December 30, 2011 Alright time to get this thread going again. High wind warnnings have been riased for much of the high plains. There is going to be a major frontal surge as well as the cold front ejects into the central high plains. We are looking at some extensive pressure rises on the order of 6-12 hpa. It is a classic high/low pattern across the Great Basin/Plains, respectively, but this time, there will be an intense tropopause undulation forcing a much more signfiicant than average mass response in the low/mid levels, i.e., quite a but of subsidence behind the front. Going to be a fun bora wind event. Link to comment Share on other sites More sharing options...
Chinook Posted December 30, 2011 Share Posted December 30, 2011 Saturday: Mostly sunny, with a high near 49. Very windy, with a northwest wind 28 to 31 mph increasing to between 41 and 44 mph. Winds could gust as high as 65 mph. Link to comment Share on other sites More sharing options...
prinsburg_wx Posted December 30, 2011 Share Posted December 30, 2011 I'll take the 18z RGEM Link to comment Share on other sites More sharing options...
baroclinic_instability Posted December 30, 2011 Author Share Posted December 30, 2011 The RGEM is definitely one of the more aggressive models as it digs the ejecint PV a little farther S then goes negative as it ejects northward. Not completely out of the question...the ejecting PV is impressive to say the leas...although it seems a bit wet even if it were to verify synoptically. Link to comment Share on other sites More sharing options...
baroclinic_instability Posted December 30, 2011 Author Share Posted December 30, 2011 If you want to get an idea of how challenging this forecast is...note the 500 hpa spread in the SREF only 24 hrs in. About 3/4ths of the members show tropofolding...while a few are weaker and suggest much less PV advection. Either way will be windy...but the ejecting of the trop undulation is key in how intense the frontal surge is...and how the cyclone develops across the plains. And the top undulation itself is definitely a meso-alpha feature, but it has wide ranging overall synoptic effects. Link to comment Share on other sites More sharing options...
Chinook Posted December 30, 2011 Share Posted December 30, 2011 How do you tell which members show tropopause folding? The maps are so small. Do you determine this based on the point of highest vorticity? Link to comment Share on other sites More sharing options...
baroclinic_instability Posted December 30, 2011 Author Share Posted December 30, 2011 It has to be inferred here based on trop maps and the corresponding 50-0 maps on the deterministic guidance, but even here it can be relatively inferred using 500 vorticity alone and the strongest gradient. Look where there is. ARW2/3 are great examples. But the 500 vorticity gradient and vorticity advection (all inferred I should add) can be correlated to where the tropopause undulation is aloft since you normally don't see that type of vorticity gradient. Link to comment Share on other sites More sharing options...
prinsburg_wx Posted December 30, 2011 Share Posted December 30, 2011 URGENT - WEATHER MESSAGE...CORRECTEDNATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN 253 PM CST FRI DEC 30 2011 ...STRONG WINDS DEVELOPING NEW YEARS EVE... .A DEEP AREA OF LOW PRESSURE AND A STRONG COLD FRONT WILL SWEEP EAST ACROSS MINNESOTA SATURDAY...TO THE LAKE SUPERIOR REGION BY EARLY SUNDAY MORNING. STRONG NORTHWEST WINDS OF 30 TO 35 MPH WITH GUSTS AROUND 55 MPH WILL BE POSSIBLE OVER WEST CENTRAL AND SOUTHWEST MINNESOTA DEVELOPING AFTER 3 PM SATURDAY. THIS WILL SPREAD EAST OVER CENTRAL AND SOUTHERN MINNESOTA INTO WEST CENTRAL WISCONSIN THROUGH SATURDAY EVENING AS THE WEATHER SYSTEM MOVES EAST. THE STRONG WINDS WILL CONTINUE THROUGH THE DAY ON SUNDAY AS WELL. A WIND ADVISORY IS IN EFFECT FROM THE AREA SOUTH OF A LINE FROM NEAR LITTLE FALLS...THE TWIN CITIES AND DURAND....FROM 3 PM SATURDAY UNTIL 6 PM SUNDAY. WINDS WILL ONLY VERY SLOWLY DIMINISH DURING THE NIGHT SUNDAY AND INTO MONDAY. Link to comment Share on other sites More sharing options...
#NoPoles Posted December 30, 2011 Share Posted December 30, 2011 at least you guys have something to talk about... Link to comment Share on other sites More sharing options...
baroclinic_instability Posted December 31, 2011 Author Share Posted December 31, 2011 Medford, Oregon 0Z sounding caught the tropopause undulation. Link to comment Share on other sites More sharing options...
baroclinic_instability Posted December 31, 2011 Author Share Posted December 31, 2011 RUC 1.5 PVU and WV. Medford OR is right underneath the PV at 23-0Z. Link to comment Share on other sites More sharing options...
prinsburg_wx Posted December 31, 2011 Share Posted December 31, 2011 The RGEM is definitely one of the more aggressive models as it digs the ejecint PV a little farther S then goes negative as it ejects northward. Not completely out of the question...the ejecting PV is impressive to say the leas...although it seems a bit wet even if it were to verify synoptically. 0z Nam trying to follow the 18z rgem idea? Link to comment Share on other sites More sharing options...
baroclinic_instability Posted December 31, 2011 Author Share Posted December 31, 2011 0Z NAM caught a clue regarding the strength of the tropo undulation. First run where it has a legit tropofold as this ejects into the plains instead of a sheared piece of junk. Big difference across MN. Quite similar to the RGEM with a period of mod-heav snow. Link to comment Share on other sites More sharing options...
StormJr Posted December 31, 2011 Share Posted December 31, 2011 About .27" QPF in 6 hours at KMSP according to the 00z NAM. Link to comment Share on other sites More sharing options...
baroclinic_instability Posted December 31, 2011 Author Share Posted December 31, 2011 About time the NAM caught a clue. That is gorgeous. A classic look to a negative tilt wave in response to a sharp PV anomaly wrapping. Link to comment Share on other sites More sharing options...
baroclinic_instability Posted December 31, 2011 Author Share Posted December 31, 2011 All the guidance coming in west and stronger now. 0Z GFS looking much more similar to the RGEM now too. Classic example of what an upper air sample can do when dealing with deep tropopause undulations. This is going to be a fun event tomorrow. Link to comment Share on other sites More sharing options...
prinsburg_wx Posted December 31, 2011 Share Posted December 31, 2011 All the guidance coming in west and stronger now. 0Z GFS looking much more similar to the RGEM now too. Classic example of what an upper air sample can do when dealing with deep tropopause undulations. This is going to be a fun event tomorrow. Do the winds look strong at the time of precip or do they come in after? Could be travel trouble later tomorrow. Link to comment Share on other sites More sharing options...
baroclinic_instability Posted December 31, 2011 Author Share Posted December 31, 2011 Do the winds look strong at the time of precip or do they come in after? Could be travel trouble later tomorrow. Mainly during thr latter half and then after as this will be along the cold frontal circulation. This is going to be a helluva fun system to track tomorrow. I am pretty excited. Link to comment Share on other sites More sharing options...
Thundersnow12 Posted December 31, 2011 Share Posted December 31, 2011 Ya...I've never seen anything like this. 85kt winds at 850mb in the CCB tomorrow evening. Link to comment Share on other sites More sharing options...
JSchwake28 Posted December 31, 2011 Share Posted December 31, 2011 Blizzard watch up for parts of eastern north dakota.. if things don't crust over today it should be pretty interesting around these parts Link to comment Share on other sites More sharing options...
StormJr Posted December 31, 2011 Share Posted December 31, 2011 Nice stripe of snow painted across the area by the 12z NAM. Slightly heavier than the previous two runs, with 0.35" now at MSP. Looks like it really starts getting crazy around here after 6z when all the crazies will be on the road! This one will be a fun one to watch! Link to comment Share on other sites More sharing options...
mayjawintastawm Posted December 31, 2011 Share Posted December 31, 2011 Upstream, looking pretty wild... after the frontal passage around 7 AM MT, 55-60 mph gusts basically everywhere in the Denver area right now (my dogs just about got blown over) and consistent gusts over 100 with a max so far of 126 reported by mesonet on a 12000 ft ridge near Frisco. Enjoy! Link to comment Share on other sites More sharing options...
#NoPoles Posted December 31, 2011 Share Posted December 31, 2011 holy winds batman!!! just read a report of a windshield imploding in the CO Springs area...in area where my friend lives...i should check in and see how she is doing! Link to comment Share on other sites More sharing options...
Srain Posted December 31, 2011 Share Posted December 31, 2011 PRELIMINARY LOCAL STORM REPORT NATIONAL WEATHER SERVICE PUEBLO CO 821 AM MST SAT DEC 31 2011 ..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON... ..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE.... ..REMARKS.. 0743 AM NON-TSTM WND GST 1 E MONARCH PASS 38.50N 106.31W 12/31/2011 M95.00 MPH CHAFFEE CO AWOS SUSTAINED WIND 84 MPH WITH GUSTS TO 95 MPH. CDOT AWOS. Link to comment Share on other sites More sharing options...
wxmeddler Posted December 31, 2011 Share Posted December 31, 2011 Dam! KMYP 311623Z AUTO 26065G89KT 1SM -TSSN BKN032 OVC042 M07/M14 A2989 RMK AO2 Link to comment Share on other sites More sharing options...
ksstormhunter Posted December 31, 2011 Share Posted December 31, 2011 17Z SmartCast Update: Looking at areas around the Brainerd, MN with highest snow accumulations through 04Z, with around 1.6" possible, with the heaviest accumulation rates of .6" from 22 to 00Z. Snow looks to begin across the Minneapolis around 03Z time with potential of 3-4" of snow, coupled with strong west-northwest winds up to 35 mph. Also Nebraska areas of Helig Field, Alliance, Sidney with some light snow accumulations of around an 1", but strong winds will be the main focus with wind gust over 60mph possible through 22Z. Full data update http://smartwxmodel.net Link to comment Share on other sites More sharing options...
Chinook Posted December 31, 2011 Share Posted December 31, 2011 A few wind gusts in the 60's. We had temperatures over 50 at 1:00am, and now it's in the 40's. Link to comment Share on other sites More sharing options...
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