Thundersnow12 Posted December 4, 2013 Share Posted December 4, 2013 MKX SLIGHT MODERATION IN TEMPERATURE BEGINS ON SUNDAY AS STRONG WEST TO NORTHWEST FLOW SUCCUMBS TO UPSTREAM AMPLIFYING LONG WAVE TROFFING OVER WESTERN CONUS. LOW TO MID-LEVEL WARM AIR ADVECTION SHIFTS INTO THE SOUTHERN WI REGION ON SUN TIGHTENING BAROCLINIC ZONE. 12Z GFS AND LATEST ECMWF CARRIES 85H CIRCULATION NORTHEAST ALONG THIS BAROCLINIC ZONE ACROSS SOUTHERN WI/NORTHERN IL AREA SUN NGT INTO MON AS MID-LEVEL SHORT WAVE TROUGH MOVES FROM THE CENTRAL PLAINS INTO THE CENTRAL GTLAKES. GFS AND ECMWF IN REASONABLE AGREEMENT ON CARRYING AROUND ONE QUARTER INCH OF QPF ACROSS MUCH OF SOUTHERN WI DURING THIS PERIOD. CRITICAL THICKNESSES FAVOR ALL SNOW. DRIER SNOW-LIQUID RATIOS OF 15 TO 20 TO ONE AND A PERIOD OF STRONGER OMEGA TAPPING INTO A DEEPER DENDRITIC GROWTH ZONE SHOULD RESULT IN SNOWFALLS OF 3 TO 6 INCHES ACROSS MOST OF THE REGION...POSSIBLY A LITTLE MORE DUE TO SOME LAKE ENHANCEMENT. WILL BE WATCHING THIS SYSTEM EVOLVE OVER THE NEXT SEVERAL DAYS BUT LOOKING MORE LIKELY THAT THE FIRST WIDESPREAD WINTER WEATHER EVENT WL AFFECT SRN WI LATE IN THE WEEKEND...POSSIBLY HAVING AN IMPACT ON MONDAY MORNING. Link to comment Share on other sites More sharing options...
Stebo Posted December 4, 2013 Share Posted December 4, 2013 MKX SLIGHT MODERATION IN TEMPERATURE BEGINS ON SUNDAY AS STRONG WEST TO NORTHWEST FLOW SUCCUMBS TO UPSTREAM AMPLIFYING LONG WAVE TROFFING OVER WESTERN CONUS. LOW TO MID-LEVEL WARM AIR ADVECTION SHIFTS INTO THE SOUTHERN WI REGION ON SUN TIGHTENING BAROCLINIC ZONE. 12Z GFS AND LATEST ECMWF CARRIES 85H CIRCULATION NORTHEAST ALONG THIS BAROCLINIC ZONE ACROSS SOUTHERN WI/NORTHERN IL AREA SUN NGT INTO MON AS MID-LEVEL SHORT WAVE TROUGH MOVES FROM THE CENTRAL PLAINS INTO THE CENTRAL GTLAKES. GFS AND ECMWF IN REASONABLE AGREEMENT ON CARRYING AROUND ONE QUARTER INCH OF QPF ACROSS MUCH OF SOUTHERN WI DURING THIS PERIOD. CRITICAL THICKNESSES FAVOR ALL SNOW. DRIER SNOW-LIQUID RATIOS OF 15 TO 20 TO ONE AND A PERIOD OF STRONGER OMEGA TAPPING INTO A DEEPER DENDRITIC GROWTH ZONE SHOULD RESULT IN SNOWFALLS OF 3 TO 6 INCHES ACROSS MOST OF THE REGION...POSSIBLY A LITTLE MORE DUE TO SOME LAKE ENHANCEMENT. WILL BE WATCHING THIS SYSTEM EVOLVE OVER THE NEXT SEVERAL DAYS BUT LOOKING MORE LIKELY THAT THE FIRST WIDESPREAD WINTER WEATHER EVENT WL AFFECT SRN WI LATE IN THE WEEKEND...POSSIBLY HAVING AN IMPACT ON MONDAY MORNING. Milwaukee never fails in throwing up a bigger than expected number. Link to comment Share on other sites More sharing options...
Gilbertfly Posted December 4, 2013 Share Posted December 4, 2013 DVN going "several inch possible" route.... AREA FORECAST DISCUSSIONNATIONAL WEATHER SERVICE QUAD CITIES IA IL331 PM CST WED DEC 4 2013.SUNDAY AND SUNDAY NIGHT WILL OFFER THE BEST CHANCE OF ANY SNOWDURING THE FORECAST PERIOD. THE NAM/GFS/ECMWF/GEM ALL SHOW A BROADSWATH OF LIGHT SNOW MOVING THROUGH LATE SUNDAY AND SUNDAY NIGHTAHEAD OF A S/W MOVING OUT OF THE NORTHERN ROCKIES. WITH GOODAGREEMENT AMOUNG THE MODELS POPS HAVE BEEN INCREASED INTO THE HIGHCHANCE AND LIKELY CATEGORIES FOR SUNDAY NIGHT. LIQUID EQUIVALENTSSHOULD BE ON THE LIGHT SIDE...NEAR OR LESS THEN A COUPLE OF TENTHSOF AN INCH...WITH P/WS PROGGED TO BE AROUND 0.3. DESPITE THE MEAGERAMOUNTS OF AVAILABLE MOISTURE...THE COLD AIRMASS WILL GENERATE HIGHSNOW TO LIQUID RATIOS...SO THE CWFA COULD SEE SEVERAL INCHES OFFLUFFY SNOW BY MONDAY MORNING. MOST GUIDANCE SEEMS TO BE TARGETINGTHE NORTHERN HALF OF THE FORECAST AREA FOR THE HIGHER AMOUNTS. Link to comment Share on other sites More sharing options...
Thundersnow12 Posted December 4, 2013 Share Posted December 4, 2013 Not much from LOT but going down the same route as DVN THEN CONTINUE TO MONITOR THE NEXT SYSTEM TO MOVE THROUGH THE REGION...WHICH WOULD BE SUNDAY INTO MONDAY. GUIDANCE APPEARS TO HAVE A FAIRLY DECENT HANDLE ON THIS SYSTEM AND IF CURRENT TRENDS CONTINUE...MOST AREAS COULD OBSERVE ACCUMULATING SNOWFALL WITH SEVERAL INCHES OF SNOWFALL POSSIBLE. Link to comment Share on other sites More sharing options...
Stebo Posted December 4, 2013 Share Posted December 4, 2013 HOWEVER...BY SUNDAY WE SHOULD SEE A STRONG ARCTIC JET PLUNGE DOWN THE WESTERN U.S. THIS WILL CARVE OUT A DEEPENING UPPER LONG WAVE TROUGH OVER THE HIGH PLAINS WHICH IN TURN PRODUCES CYCLOGENESIS OVER THE WESTERN GULF. THE MODELS ARE IN GOOD AGREEMENT BRINGING THE SURFACE LOW TOWARD THE LOWER GREAT LAKES BY SUNDAY NIGHT AND INTENSIFYING THE LOW AS IT MOVES NE ACROSS THE EASTERN LOWER PENINSULA. THIS COULD SPELL A DECENT SNOWFALL FROM MUCH OF THE CWA...HIGHEST NW...ALONG WITH INCREASING WINDS INTO MONDAY. DTX is going with a decent snowfall, whatever that means... HIGH PRESSURE BUILDS INTO THE GREAT LAKES ON SATURDAY AND WILL HOLD THROUGH SUNDAY MORNING BRINGING BELOW NORMAL TEMPERATURES TO MICHIGAN. BY SUNDAY AFTERNOON...A LOW PRESSURE SYSTEM WILL BE PUSHING CLOSER TO SE MI WITH THE MODELS SHOWING THE LOW TRACKING ACROSS THE EASTERN GREAT LAKES SUNDAY NIGHT INTO MONDAY. MAIN CONCERN WITH THIS SYSTEM WILL BE PRECIPITATION TYPE AND TIMING AS IT LOOKS LIKE SE MI WILL BE MAINLY ALL SNOW WITH THE POTENTIAL FOR SOUTHEASTERN AREAS OF THE CWA SEEING A BRIEF RAIN/SNOW MIX MONDAY MORNING. SCATTERED SNOW SHOWERS MAY LINGER BEHIND AS THE LOW TRACKS OFF TO THE NORTHEAST MONDAY/TUESDAY AND NORTHWESTERLY FLOW SETS UP. HIGH PRESSURE WILL THEN BUILD BACK INTO THE AREA WEDNESDAY AND THURSDAY...WITH A REINFORCING SHOT OF EVEN COLDER AIR AS HIGHS ARE ONLY EXPECTED TO REACH AROUND 20 DEGREES. GRR is mentioning potential precip type issues in their far SE, my guess is they think the low is going to track further northwest than current model depictions as models aren't showing precip type issues here even. Link to comment Share on other sites More sharing options...
wisconsinwx Posted December 4, 2013 Share Posted December 4, 2013 Yeah, Usingers have gone to their head. As modeled, mkx is not far off, but it is sure to change, which is why even ranges are dangerous at this point. Link to comment Share on other sites More sharing options...
Thundersnow12 Posted December 4, 2013 Share Posted December 4, 2013 18z GFS still cranking out 3" for most of northern IL with a touch more along the IL/WI and north. Link to comment Share on other sites More sharing options...
Stebo Posted December 4, 2013 Share Posted December 4, 2013 I really think the GFS is being cheap with the cold sector precip, it is also showing too weak of a low pressure compared to what I think will verify. Link to comment Share on other sites More sharing options...
wisconsinwx Posted December 4, 2013 Share Posted December 4, 2013 Well if the euro stays consistent with its most recent run with over a quarter inch of precipitation in many areas, I will start to favor it. As of now, I will give equal weight to the euro and gfs. Link to comment Share on other sites More sharing options...
Thundersnow12 Posted December 4, 2013 Share Posted December 4, 2013 I really think the GFS is being cheap with the cold sector precip, it is also showing too weak of a low pressure compared to what I think will verify. The 12z run was actually a good bit stronger tanking the sfc low from 1012mb to 1006mb in 6hr overnight Sunday into Monday and the new run backed off that idea and has it strength much slower. Link to comment Share on other sites More sharing options...
Hoosier Posted December 4, 2013 Share Posted December 4, 2013 Question for the mets... could this be a scenario where the snow/ice on Friday has an impact in forcing a farther south track of the Sunday low since the Sunday event is not some deep surface low/negatively tilted upper trough? Link to comment Share on other sites More sharing options...
Chicago Storm Posted December 4, 2013 Author Share Posted December 4, 2013 I really think the GFS is being cheap with the cold sector precip. The weak cold sector precip is to be expected in this kind of scenario. Link to comment Share on other sites More sharing options...
Stebo Posted December 4, 2013 Share Posted December 4, 2013 The weak cold sector precip is to be expected in this kind of scenario. Not this weak, and that is due to the very weak low pressure being shown which is being underdone. I am not expecting some sort of explosive cold sector, but I do think more moisture will end up in the cold sector than current model depictions. Link to comment Share on other sites More sharing options...
snowlover2 Posted December 4, 2013 Share Posted December 4, 2013 Question for the mets... could this be a scenario where the snow/ice on Friday has an impact in forcing a farther south track of the Sunday low since the Sunday event is not some deep surface low/negatively tilted upper trough? Wondering the same thing myself. Link to comment Share on other sites More sharing options...
Stebo Posted December 4, 2013 Share Posted December 4, 2013 Question for the mets... could this be a scenario where the snow/ice on Friday has an impact in forcing a farther south track of the Sunday low since the Sunday event is not some deep surface low/negatively tilted upper trough? This could be possible but I don't think it will be a significant change in the track. The low might eject further south, but it will eventually lift north northeast as the vort rounds the base of the longwave trough. Link to comment Share on other sites More sharing options...
Hoosier Posted December 4, 2013 Share Posted December 4, 2013 IMO we'd need some wholesale change in the setup to get a big increase in the precip output given the positively tilted trough and brunt of the LLJ focus remaining in the OV. Link to comment Share on other sites More sharing options...
buckeye Posted December 4, 2013 Share Posted December 4, 2013 Question for the mets... could this be a scenario where the snow/ice on Friday has an impact in forcing a farther south track of the Sunday low since the Sunday event is not some deep surface low/negatively tilted upper trough? I'm wondering about the effects of a snowcover as well...not so much with track of low, but more to do with colder surface temps prolonging a freezing rain event for those of us in the potential mix zone. Link to comment Share on other sites More sharing options...
Hoosier Posted December 4, 2013 Share Posted December 4, 2013 This could be possible but I don't think it will be a significant change in the track. The low might eject further south, but it will eventually lift north northeast as the vort rounds the base of the longwave trough. Thanks. I guess at the very least it could delay the snow/ice covered areas warming above freezing. Link to comment Share on other sites More sharing options...
Stebo Posted December 4, 2013 Share Posted December 4, 2013 Thanks. I guess at the very least it could delay the snow/ice covered areas warming above freezing. Yes to an extent, the further east you go the smaller/narrow the snow/ice coverage will be plus the LLJ will be focused into that region as well. Link to comment Share on other sites More sharing options...
Chicago Storm Posted December 4, 2013 Author Share Posted December 4, 2013 Not this weak, and that is due to the very weak low pressure being shown which is being underdone. I am not expecting some sort of explosive cold sector, but I do think more moisture will end up in the cold sector than current model depictions. Not so much, Re: SLP. The problem is there isn't a developed ULL aiding in moisture transport...Due to how phasing occurs and the northern stream dropping in from Canada being dominant. Link to comment Share on other sites More sharing options...
Stebo Posted December 4, 2013 Share Posted December 4, 2013 Not so much, Re: SLP. The problem is there isn't a developed ULL aiding in moisture transport...Due to how phasing occurs and the northern stream dropping in from Canada being dominant. Sure a separate ULL would help aid in moisture transport, but that isn't an option with this system so it is an irrelevant point to bring up. If that were possible with this system, this would evolve and phase completely differently. Link to comment Share on other sites More sharing options...
Chicago Storm Posted December 4, 2013 Author Share Posted December 4, 2013 Sure a separate ULL would help aid in moisture transport, but that isn't an option with this system so it is an irrelevant point to bring up. If that were possible with this system, this would evolve and phase completely differently. It's not irrelevant. Not having a decent ULL in this kind of scenario kills cold sector precip. The only thing that could help is if you were to get a stronger inverted trough scenario. ...Otherwise don't expect too much more cold sector QPF in future runs. Link to comment Share on other sites More sharing options...
Stebo Posted December 4, 2013 Share Posted December 4, 2013 It's not irrelevant. Not having a decent ULL in this kind of scenario kills cold sector precip. The only thing that could help is if you were to get a stronger inverted trough scenario. ...Otherwise don't expect too much more cold sector QPF in future runs. We will see how it plays out then, note I am not calling for something spectacular but I don't think the current QPF in the cold sector is correct per the GFS, nor do the weather service offices in the region. Link to comment Share on other sites More sharing options...
cyclone77 Posted December 4, 2013 Share Posted December 4, 2013 Not looking like too big a deal as a whole, but liking the trends of today's guidance. Stepped up amounts a bit, which should yield a nice, widespread 1-3" type event. It will be nice to see some snow cover, no matter how meager after the last few Decembers. Link to comment Share on other sites More sharing options...
Hoosier Posted December 4, 2013 Share Posted December 4, 2013 Not sure it's worth squabbling over what may ultimately amount to a difference of like .1 qpf. The GFS has like a 300 mb deep DGZ in the areas well northwest of the track which should lead to pretty impressive ratios even if qpf ends up on the lower side. Link to comment Share on other sites More sharing options...
Thundersnow12 Posted December 5, 2013 Share Posted December 5, 2013 Not sure it's worth squabbling over what may ultimately amount to a difference of like .1 qpf. The GFS has like a 300 mb deep DGZ in the areas well northwest of the track which should lead to pretty impressive ratios even if qpf ends up on the lower side. Was looking at that for here earlier. 100-200mb deep for a time around here it looked like just glancing before losing some mid-level moisture. Link to comment Share on other sites More sharing options...
snowstormcanuck Posted December 5, 2013 Share Posted December 5, 2013 Usually the GEFS are good for 1 or 2 monster wrapped up members. Not a one this time. Link to comment Share on other sites More sharing options...
Hoosier Posted December 5, 2013 Share Posted December 5, 2013 Was looking at that for here earlier. 100-200mb deep for a time around here it looked like just glancing before losing some mid-level moisture. It's even deeper farther west. I pulled some soundings for Des Moines and it's a good 300-350 mb deep for much of the time. Link to comment Share on other sites More sharing options...
SchaumburgStormer Posted December 5, 2013 Share Posted December 5, 2013 Not looking like too big a deal as a whole, but liking the trends of today's guidance. Stepped up amounts a bit, which should yield a nice, widespread 1-3" type event. It will be nice to see some snow cover, no matter how meager after the last few Decembers. Considering it was well into January before I eclipsed the inch mark last year, I will gladly take whatever this system squeezes out. Go go gadget surprise 6" Link to comment Share on other sites More sharing options...
michsnowfreak Posted December 5, 2013 Share Posted December 5, 2013 Hoping this one produces! Lake effect potential should be excellent after the L passes too, but direction remains to be seen (W, NW, or NNW). Link to comment Share on other sites More sharing options...
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