CoastalWx Posted April 21, 2012 Author Share Posted April 21, 2012 The mid level theta-e advection is off the charts. Given the amount of mid and upper level frontogenesis and the presence of -EPV with extreme deep height falls...there is a legit shot at some TSSN. Hey Baro check this out. It's a crude way of taking things like -EPV together but works just as well. It's nailed the idea of TSSN before. Look at the pocket of LIs below zero just west of the tughill. Even where the LIs are near zero, that tells me the atmosphere is at least conditionally unstable. That will help form one of those -EPV bands right ahead of the dryslot where theta surfaces may fold and there is your TSSN. Link to comment Share on other sites More sharing options...
OSUmetstud Posted April 21, 2012 Share Posted April 21, 2012 We will have to watch the evolution of the upper level low...you want the flow to turn due easterly with the 500mb low cut-off to your south and southeast. The tear drop shape on the NAM allows ESE flow in the mid-levels so warm air and the dry slot advances. I think that's why the NAM actually had sleet mixing in as 800mb temps rose to 1C in BUF. Link to comment Share on other sites More sharing options...
OSUmetstud Posted April 21, 2012 Share Posted April 21, 2012 BUF has issued a winter storm watch...10 to 16" in southern Erie and the Western Southern Tier and 4-8" in the Niagara Frontier. Link to comment Share on other sites More sharing options...
CoastalWx Posted April 21, 2012 Author Share Posted April 21, 2012 We will have to watch the evolution of the upper level low...you want the flow to turn due easterly with the 500mb low cut-off to your south and southeast. The tear drop shape on the NAM allows ESE flow in the mid-levels so warm air and the dry slot advances. I think that's why the NAM actually had sleet mixing in as 800mb temps rose to 1C in BUF. Yeah sometimes these wrap up and the dryslot punches in further west. Part of me likes south of BUF for that reason, but verbatim euro looked nice. Link to comment Share on other sites More sharing options...
baroclinic_instability Posted April 21, 2012 Share Posted April 21, 2012 Hey Baro check this out. It's a crude way of taking things like -EPV together but works just as well. It's nailed the idea of TSSN before. Look at the pocket of LIs below zero just west of the tughill. Even where the LIs are near zero, that tells me the atmosphere is at least conditionally unstable. That will help form one of those -EPV bands right ahead of the dryslot where theta surfaces may fold and there is your TSSN. That works for me! That is pretty much where I was thinking based off mid level theta-e plots. Another crude and simple way to view the possibility is simply looking at upper level tropopause 1.5 PV and low level theta-e. Monday morning/afternoon looks prime. Link to comment Share on other sites More sharing options...
baroclinic_instability Posted April 21, 2012 Share Posted April 21, 2012 We will have to watch the evolution of the upper level low...you want the flow to turn due easterly with the 500mb low cut-off to your south and southeast. The tear drop shape on the NAM allows ESE flow in the mid-levels so warm air and the dry slot advances. I think that's why the NAM actually had sleet mixing in as 800mb temps rose to 1C in BUF. Lots of scenarios seem to be on the table, but guidance is hinting more at a rapid intensification than a slow intensification rate like the NAM. If anything I can see this going deeper than the ECMWF. Faster deepening would shunt WAA eastward. Link to comment Share on other sites More sharing options...
OSUmetstud Posted April 21, 2012 Share Posted April 21, 2012 Lots of scenarios seem to be on the table, but guidance is hinting more at a rapid intensification than a slow intensification rate like the NAM. If anything I can see this going deeper than the ECMWF. Faster deepening would shunt WAA eastward. right...I should have been clearer, too. I'm talking about partial T/partial t, not WAA. WAA is an obviously an important factor in getting the strong lift into the cold sector. Link to comment Share on other sites More sharing options...
CoastalWx Posted April 21, 2012 Author Share Posted April 21, 2012 That works for me! That is pretty much where I was thinking based off mid level theta-e plots. Another crude and simple way to view the possibility is simply looking at upper level tropopause 1.5 PV and low level theta-e. Monday morning/afternoon looks prime. Nice, looks like it gets down below 500mb. Should be some fun things happening. Link to comment Share on other sites More sharing options...
blackngoldrules Posted April 21, 2012 Share Posted April 21, 2012 Based on the 12z model runs, would you say it would be prudent to start hoisting WSW's in Western PA? Check the Pittsburgh thread. WSW is up now. They're buying into it now it looks like. Link to comment Share on other sites More sharing options...
powderfreak Posted April 21, 2012 Share Posted April 21, 2012 Around 2.50" of QPF for KJHW on the 06z NAM, mostly as snow. Tbh, I'd be more than happy with 4". You are going to get crushed... please have a digital camera ready and charge the batteries We will live vicariously through you there at 1,300ft. Link to comment Share on other sites More sharing options...
powderfreak Posted April 21, 2012 Share Posted April 21, 2012 URGENT - WINTER WEATHER MESSAGE NATIONAL WEATHER SERVICE BUFFALO NY 330 PM EDT SAT APR 21 2012 NYZ012-019>021-085-220330- /O.NEW.KBUF.WS.A.0001.120423T0300Z-120423T2300Z/ WYOMING-CHAUTAUQUA-CATTARAUGUS-ALLEGANY-SOUTHERN ERIE- INCLUDING THE CITIES OF...WARSAW...JAMESTOWN...OLEAN... WELLSVILLE...ORCHARD PARK...SPRINGVILLE 330 PM EDT SAT APR 21 2012 ...WINTER STORM WATCH IN EFFECT FROM SUNDAY EVENING THROUGH MONDAY EVENING... THE NATIONAL WEATHER SERVICE IN BUFFALO HAS ISSUED A WINTER STORM WATCH...WHICH IS IN EFFECT FROM SUNDAY EVENING THROUGH MONDAY EVENING. * LOCATIONS...SOUTHERN ERIE AND WYOMING COUNTIES AND THE WESTERN SOUTHERN TIER * TIMING...SUNDAY EVENING THROUGH MONDAY. * HAZARDS...ACCUMULATING HEAVY WET SNOW. * ACCUMULATIONS...10 TO 16 INCHES. * WINDS...NORTHEAST TO 40 MPH. * VISIBILITIES BELOW A HALF MILE AT TIMES. * IMPACTS...WIDESPREAD DOWNED TREES AND POWER LINES CAUSING POWER OUTAGES. HAZARDOUS DRIVING CONDITIONS DEVELOPING. * FORECASTER CONFIDENCE...HIGH. Link to comment Share on other sites More sharing options...
Paweatherguy1 Posted April 21, 2012 Share Posted April 21, 2012 Sounds to me, per some of the wording in the NWS watches, that blizzard conditions are absolutely possible? Link to comment Share on other sites More sharing options...
lakeeffectkid383 Posted April 21, 2012 Share Posted April 21, 2012 3" or more will start causing damage here for sure. If we saw 6" or more you can be positive we will start seeing serious outages. For those south of here all i have to say is get ready and yes WNYLakeeffect you better have your camera ready as will i. Got my sony bloggie 1080p video camera. Can get up to 2 hours of 1080p video. Link to comment Share on other sites More sharing options...
baroclinic_instability Posted April 21, 2012 Share Posted April 21, 2012 Pretty much on cue the 18Z NAm is tightening up the low much earlier..stalling it more. Also a tick deeper. Link to comment Share on other sites More sharing options...
Gorizer Posted April 21, 2012 Share Posted April 21, 2012 KBUF: IN TERMS OF HOW POTENTIALLY UNUSUAL THIS WHOLE EVENT COULD BE (ESP THE SNOW ASPECT OF IT)...NEARLY ALL OF THE MAJOR FORECAST PARAMETERS (500MB AND 700MB HEIGHTS...MSLP...850MB TEMPS...AND WIND COMPONENTS) ARE 4 TO 5 STANDARD DEVIATIONS FROM NORMAL. IT IS CERTAINLY SIGNIFICANT WHEN A COUPLE FORECAST PARAMETERS ARE THAT ANOMALOUS... BUT WHEN NEARLY ALL OF THE MAIN FACTORS ARE THIS FAR FROM NORMAL...THEN THE EVENT STARTS TO RISE TO THAT OF A MEMORABLE OR EVEN HISTORIC STATURE...IF ALL OF THESE FACTORS REMAIN IN PERFECT ALIGNMENT. Link to comment Share on other sites More sharing options...
WNYLakeEffect Posted April 21, 2012 Share Posted April 21, 2012 I only have an iPhone to take pics, but if it gets interesting enough, I'll take some. If we were to get >12" of snow, it would be the 2nd latest on record, just beating April 20-21, 1901, which was the largest April snowstorm on record (22.5"). The only later date was April 30-May 1, 1908. Link to comment Share on other sites More sharing options...
OSUmetstud Posted April 21, 2012 Share Posted April 21, 2012 Pretty much on cue the 18Z NAm is tightening up the low much earlier..stalling it more. Also a tick deeper. if that stalls does take place....I bet the highest elevations of WPA will be the winner. Link to comment Share on other sites More sharing options...
Paweatherguy1 Posted April 21, 2012 Share Posted April 21, 2012 Hour 51 24hr precip total, things starting to rap up.... Absolutely unbelievable. Link to comment Share on other sites More sharing options...
powderfreak Posted April 21, 2012 Share Posted April 21, 2012 I would love to be in the high terrain in western NY. I guess it is possible for some of those snow amounts to verify given the combo upslope and intense deformation/frontogenesis if everything comes together perfectly. Yeah looking at progs and seeing temps falling into the upper 20s at that elevation... plus any enhanced cooling from forced orographic lift, they may be able to get away with somewhat decent ratios all things considered in the hills SW of BUF. Link to comment Share on other sites More sharing options...
lakeeffectkid383 Posted April 21, 2012 Share Posted April 21, 2012 18z NAM looks better for BUF further east and colder. Link to comment Share on other sites More sharing options...
Geos Posted April 21, 2012 Share Posted April 21, 2012 Looking pretty intense on the 18z NAM. State College issued watches in their western CWA. Link to comment Share on other sites More sharing options...
CoastalWx Posted April 21, 2012 Author Share Posted April 21, 2012 KBUF: IN TERMS OF HOW POTENTIALLY UNUSUAL THIS WHOLE EVENT COULD BE (ESP THE SNOW ASPECT OF IT)...NEARLY ALL OF THE MAJOR FORECAST PARAMETERS (500MB AND 700MB HEIGHTS...MSLP...850MB TEMPS...AND WIND COMPONENTS) ARE 4 TO 5 STANDARD DEVIATIONS FROM NORMAL. IT IS CERTAINLY SIGNIFICANT WHEN A COUPLE FORECAST PARAMETERS ARE THAT ANOMALOUS... BUT WHEN NEARLY ALL OF THE MAIN FACTORS ARE THIS FAR FROM NORMAL...THEN THE EVENT STARTS TO RISE TO THAT OF A MEMORABLE OR EVEN HISTORIC STATURE...IF ALL OF THESE FACTORS REMAIN IN PERFECT ALIGNMENT. The AFD pretty much says it all. Link to comment Share on other sites More sharing options...
OSUmetstud Posted April 21, 2012 Share Posted April 21, 2012 weird about face by HPC on snow amounts for the niagara frontier lol. Maybe it's because it's between days 2 and 3? Link to comment Share on other sites More sharing options...
OSUmetstud Posted April 21, 2012 Share Posted April 21, 2012 Allegheny Mountains in Northern WVA are also going to get crushed...could end up being the winners? Link to comment Share on other sites More sharing options...
lakeeffectkid383 Posted April 21, 2012 Share Posted April 21, 2012 Allegheny Mountains in Northern WVA are also going to get crushed...could end up being the winners? What do you think for BUF? Link to comment Share on other sites More sharing options...
jonjon Posted April 21, 2012 Share Posted April 21, 2012 Allegheny Mountains in Northern WVA are also going to get crushed...could end up being the winners? I'll be pulling for that. At least we don't have much leaves out yet. Link to comment Share on other sites More sharing options...
Geos Posted April 21, 2012 Share Posted April 21, 2012 You definitely see the NW flow enhancing the moisture over the higher terrain in far western NY, western PA, & northern WV on this total qpf map: Link to comment Share on other sites More sharing options...
OSUmetstud Posted April 21, 2012 Share Posted April 21, 2012 What do you think for BUF? I'm not ready to stick my neck out yet. Link to comment Share on other sites More sharing options...
toronto blizzard Posted April 21, 2012 Share Posted April 21, 2012 I'm not ready to stick my neck out yet. Do you think here in YYZ we have a shot at something decent. EC is already saying nothing for us. Link to comment Share on other sites More sharing options...
nzucker Posted April 21, 2012 Share Posted April 21, 2012 I'll be pulling for that. At least we don't have much leaves out yet. This is a perfect track for WV...the low intensifies over the Delmarva and then retrogrades a bit, maintaining a strong NW upslope flow. Looks amazing. Link to comment Share on other sites More sharing options...
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