February 25-27 Winter Storm Part 2

[stormtrackertf]

10" lollipop over BowMe.

 

Not minding that 6-8" area over top of me, even though with those temps that would be more like 4-6" of depth.

[Stebo]

DTX's AFD, can't disagree with what they are saying at all. Looks pretty solid

 

 

THE SYSTEM IS NOW BEGINNING TO COME TOGETHER OVER THE SOUTHERNPLAINS. THE MID/UPPER LEVEL WAVE HAS FINISHED DIGGING SOUTHWARD ANDIS NOW PHASING WITH THE SUBTROPICAL JET OVER WEST TEXAS WHICH WILLALLOW IT TO QUICKLY ORGANIZE AND STRENGTHEN. THE TROUGH WILLTRANSITION TO A NEGATIVE TILT AS IT TRACK EASTWARD WITH THE SFCREFLECTION REACHING FULL MATURITY BY MONDAY NIGHT OVERARKANSAS/LOUISIANA. THE NOW OCCLUDING SYSTEM WILL TURN NE INTO THEOHIO VALLEY WITH THE NORTHERN FRINGE OF THE PRECIP SHIELD REACHINGSOUTHERN MI TUESDAY MORNING. THE MAIN AREA OF PRECIP IS ADVERTISEDTO SLIDE NORTH THROUGH THE CWA TUESDAY AFTERNOON AND OVERNIGHTBEFORE THE SYSTEM TRACKS EAST AWAY FROM THE AREA. SOME LINGERINGSNOW SHOWERS WILL CONTINUE WHEN THE DEFORMATION BAND PIVOTS THROUGHTHE AREA ON WEDNESDAY.THE SYSTEM WILL BRING ABUNDANT MOISTURE WITH IT HAVING ORIGINATEDIN THE DEEP SOUTH DRAWING IN PLENTY OF MOISTURE FROM THE GOM. INADDITION...AS THE LOW APPROACHES THE OHIO VALLEY THE OCCLUDED FRONTWILL EXTEND TO THE ATLANTIC COAST AND WILL EITHER SPIN UP ASECONDARY LOW OR AT LEAST ELONGATE THE PRESSURE PATTERN EASTWARD.THIS WILL PROVIDE A BOOST OF MOISTURE STREAMING WESTWARD FROM THEATLANTIC. MODELS ARE ADVERTISING UP TO 0.75 PWATS WITH SPECIFICHUMIDITIES OF 3-4 G/KG EXTENDING UP TO 700MB. MOST MODEL QPF FIELDSSHOW AROUND 0.6-0.8 INCHES OF LIQUID FALLING IN ABOUT A 12 HOURSPERIOD FROM 18Z TUES TO 06Z WED. THIS COINCIDES WITH A STRONG FGENBAND SWEEPING NORTHWARD AHEAD OF THE LOW WITH GOOD ISENTROPICACCENT. CONCERN STILL LIES WITH THE THERMAL PROFILE AS WARM AIRINTRUSION MAY LEAD TO RAINFALL OR A RAIN/SNOW MIX ACROSS MAINLY FORLOCATIONS SOUTH OF A LINE FROM ANN ARBOR TO DETROIT. MODEL SOUNDINGSDO NOT SHOW AN INCREDIBLY DEEP WARM LAYER...SOMEWHERE BETWEEN850-750MB...WARMING JUST ABOVE 0C WITH A 50 KNOT LLJ HELPING BRINGIN THE WARM AIR. 950MB TEMPS ON THE OTHER HAND WILL STAY AOB 0C FORMOST OF THE EVENT. THOUGHT PROCESS IS THAT WITH A SHALLOW LAYERWHICH DOES NOT APPEAR TOO WARM...WET BULBING WITH THE HIGH PRECIPRATES WILL ALL ENOUGH COOLING TO KEEP PRIMARILY A HEAVY WET SNOW.REGARDLESS...THE WARM AIR WILL KEEP SNOW RATIOS DOWN CLOSE TO 8:1.A WINTER STORM WATCH WAS ISSUED WITH THE PREVIOUS FORECAST PACKAGEAND WILL CONTINUE AS IS FOR THE POTENTIAL FOR A 6+ INCH SNOWFALLACROSS THE AREA. CURRENT FORECAST IS CALLING FOR LOWEST AMOUNTS OVERTHE SAGINAW VALLEY AS BULK OF PRECIP IS SHOWN TO SHED MORE EAST THENNORTH AND THE EXTREME SOUTH DUE TO WARM AIR INTRUSION. BUT THERE ISSTILL POTENTIAL FOR SEVERAL INCHES OF WET HEAVY SNOW FOR ALL AREAS.THERE IS MUCH LEFT TO BE DETERMINED WITH THIS SYSTEM SUCH AS HOW FARNORTH THE WARM AIR AND RAIN WILL PROGRESS...HOW STRONG WILL THE FGENBAND BE AS IS TRAVERSES THE AREA...WHAT TRACK WILL THE LOW ITSELFTAKE (NAM SAYS IT STALLS RIGHT OVER SOUTHERN MI WHEREAS THE GFSPULLS IT QUICKLY EASTWARD TOWARD THE DEVELOPING PRESSURE FALLS)WHICH WILL DETERMINE THE PATH OF THE TRAILING DEFORMATIONBAND...ETC. MORE DETAILS TO COME...

 

While GRR is already discussion probably downgrade to advisory

 

 

THE MAIN PERIOD OF CONCERN FOR THE INCOMING SYSTEM LOOKS TO BE FROMLATE TUE MORNING THROUGH THE OVERNIGHT HOURS ON WED. THE MODELS AREGENERALLY IN AGREEMENT WITH EACH OTHER WITH REGARD TO THE EVOLUTIONOF THE SYSTEM. THE INITIAL UPPER LOW NOW ACROSS NEW MEXICO WILL LIFTTO THE NE THROUGH TOMORROW. ADDITIONAL STRONG ENERGY NOW JUST ABOUTTO MOVE ONSHORE ACROSS THE PACIFIC NW WILL DIG ACROSS THE ROCKIESAND EVENTUALLY PHASE WITH THE NM LOW.WE WILL SEE PCPN MOVE IN LATE TUE MORNING THROUGH TUE EVENING FROMSOUTH TO NORTH AS A 50 KT LLJ HELPS TO TRANSPORT A HEALTHY SURGE OFWARM AND MOIST AIR FROM THE GULF AHEAD OF THE OCCLUDING FRONT.MODELS INDICATE THAT FAIRLY STRONG VERTICAL MOTION WILL ACCOMPANYTHIS SURGE. IN ADDITION...THIS BEST LIFT ALOFT WILL BE FAIRLY CLOSETO THE DGZ AND SOME WEAKNESS IN THE STABILITY ALOFT WILL PROVIDE FORA NICE BURST OF PCPN. THE PCPN SHOULD BE MAINLY IN THE FORM OF SNOWAS SOME SLIGHTLY ABOVE ZERO AIR ALOFT WILL WET BULB DOWN QUICKLY ASTHE PCPN MOVES IN. SOME SLEET WILL BE POSSIBLE DOWN SOUTH AT THEONSET.WE EXPECT THE BAND OF SNOW TO LAST A SHORT TIME BEFORE THE BANDSHIFTS NORTH THROUGH THE AREA. THE HEAVIEST OF THE PCPN WITH THISSYSTEM WILL BE SHUNTED SE OF THE AREA WHERE THE SECONDARY LOWDEVELOPMENT WILL TAKE PLACE AND WHERE THE MOISTURE WILL BE DIRECTED.WE STILL EXPECT THE SNOW TO BE SOMEWHAT INTENSE FOR THE REASONSLISTED ABOVE. THIS INTENSE BAND WILL BE SHORT LIVED AT ANY ONELOCATION HOWEVER AND WILL GRADUALLY WEAKEN AS IT MOVES NORTHEAST.THIS WILL OCCUR DURING THE TUE AFTERNOON COMMUTE IN GENERAL...SOTHERE WILL LIKELY BE IMPACTS.AFTER THE INITIAL BAND MOVES THROUGH...THERE MAY BE A BRIEF BREAK INTHE SNOW. THE MODELS ARE INDICATING ANOTHER BAND...MORE CLOSELYASSOCIATED WITH THE UPPER LOW AND LIKELY THE DEFORMATIONBAND/TROWAL. THIS WILL MOVE IN AFTER DARK AND AGAIN AFFECT THE AREAFOR A FEW HOURS. THIS IS NOT EXPECTED TO BE AS INTENSE AS THEENERGY...MOISTURE...AND WARM AIR WILL BE TRANSFERRING EAST BY THISTIME. THIS WILL BRING OUR SECOND AND LAST BEST CHANCE FORACCUMULATING SNOW. ONCE THIS MOVES THROUGH...WE WILL SETTLE INTO APERIOD OF AREAS OF LIGHT SNOW WITH LIMITED ACCUMULATIONS.AT THIS TIME WE ARE GENERALLY THINKING MOST AREAS WILL SEE 3 TOLOCALLY 6 INCHES OF SNOW THROUGH TUE NIGHT. WE ENVISION THE WATCHEVENTUALLY GOING TO AN ADVISORY...BUT THE CONFIDENCE IS NOT THEREYET TO DO THIS. WITH ONE PIECE OF ENERGY STILL YET TO COME INTO THERAOB NETWORK TODAY...SOME CHANGES REMAIN POSSIBLE WITH THE TRACK ASTHE MODELS TRY TO HANDLE THE PHASING OF THE ENERGY.THE MODELS ARE SHOWING UP TO 0.60 INCHES OF QPF FOR MOST OF THEAREA. THE HIGHEST AMOUNTS WILL BE DOWN SOUTH WHERE BETTER PCPN WILLFALL BEFORE ENERGY TRANSFERS EAST. EVEN THOUGH QPF AMOUNTS AREDECENTLY HIGH...A HIGH DGZ AND MILD COLUMN WILL ONLY SUPPORT LOWSNOW TO WATER RATIOS. HIGHER RATIOS WILL BE FOUND UNDER THE BETTERBANDS...BUT THESE WILL BE SHORT IN DURATION. ALSO...SFC TEMPS AREEXPECTED TO BE AROUND OR SLIGHTLY ABOVE FREEZING THROUGH MOST OF THEEVENT. THIS WILL LIMIT ACCUMS A LITTLE. SOME LOCAL AREAS COULD SEELOCALLY HIGHER AMOUNTS.

[BowMeHunter]

didn't expect the gfs to be even worse.. I toss 4sho.

 

Going to be brutal waiting for the euro 12z

[Stebo]

GFS cut the snow totals here locally but it is still having major issues with dynamic cooling. The QPF looked pretty much the same so just another GFS **** up.

[Harry]

Problem the models seem to be having now has to do with that stuff they now show diving in on the backside of this storm which was not there a few days ago. Unfortunately that wont get totally resolved till it is onshore out west.

[snowstormcanuck]

Another YYZ weenie run on the 6z GFS.

[snowstormcanuck]

yeah you're in the sweet and pretty dam high confidence spot.  no way I'd be sweating the NAM and its actually in a great spot to give you even more confidence in a euro solution being the one.

 

Toronto is getting croaked no matter if the NAM is right which it isn't.

 

I hope croaked is a good thing.

[AppsRunner]

I went to bed thinking the 0z NAM was the beginning of a trend that was going to send this storm further north and warmer. Shrugged it off. I had my foot snowstorm this year. Can't be greedy. It didn't end up being a trend, so lucky me, but still if you can use whatever pull you have with the wx gods to get yby a good snowstorm you do it. Leave me in the rain if you must.

 

Yeah I thought most of Indiana and all of Ohio were gonna be able to call off any significant snows by the 12z cycle... but if the 6z GFS/NAM were any indication of a start of a southern trend then maybe not. Going to be a wild ride for the northern and southern edges in the next 36hrs

[Toronto4]

Another YYZ weenie run on the 6z GFS.

 

My preliminary call for the GTA is 6-12". 6-7" by the lakeshore to Queen St, 7-10" Queen St. to highway 401 and 10-12" hwy 401 to Vaughan/Markham.

 

For reference purposes, there was a sharp snow-rain line within the downtown core back on Dec. 9th, 2009. An inch at Queens Park and nothing by the lakeshore.

[zero26800]

Yeah I thought most of Indiana and all of Ohio were gonna be able to call off any significant snows by the 12z cycle... but if the 6z GFS/NAM were any indication of a start of a southern trend then maybe not. Going to be a wild ride for the northern and southern edges in the next 36hrs

 

I was thinking the same last night, but we shall see if it starts to trend that way or just a useless run.

[mississaugasnow]

Another YYZ weenie run on the 6z GFS.

Greetings from Asia. Looks like I've missed a lot of active weather. Hope you guys enjoyed that monster of a storm earlier this month. My flight is from Hong Kong to Toronto landing around 7pm Wednesday. I'm assuming most of the storm will be done by then correct? Hoping that there is no delay. Also on a side note, the first special weather statement I've read since December mentions mixing issues along the Lake Ontario shoreline. Must know I'm coming home.

[Harry Perry]

GRR thinking that this event will be solid advisory material, everyone else sticking with warning criteria.

I'm not sold on Warning snows yet tho either... Still have some time to make the final call and see what this last piece of energy has.

[snowstormcanuck]

Greetings from Asia. Looks like I've missed a lot of active weather. Hope you guys enjoyed that monster of a storm earlier this month. My flight is from Hong Kong to Toronto landing around 7pm Wednesday. I'm assuming most of the storm will be done by then correct? Hoping that there is no delay. Also on a side note, the first special weather statement I've read since December mentions mixing issues along the Lake Ontario shoreline. Must know I'm coming home.

 

lol. If you can still go back to KW, go. It's gonna be the bomb over there.

 

And yeah, the worst should be over by 7pm Weds.

[snowstormcanuck]

My preliminary call for the GTA is 6-12". 6-7" by the lakeshore to Queen St, 7-10" Queen St. to highway 401 and 10-12" hwy 401 to Vaughan/Markham.

 

For reference purposes, there was a sharp snow-rain line within the downtown core back on Dec. 9th, 2009. An inch at Queens Park and nothing by the lakeshore.

 

I'm going to stick with my more conservative numbers for now. I think I'm going to be in wait and see mode right until a couple of hours before the event starts. The bomb/bust line is too thin to go nuts with amounts at this point.

[toronto blizzard]

I'm going to stick with my more conservative numbers for now. I think I'm going to be in wait and see mode right until a couple of hours before the event starts. The bomb/bust line is too thin to go nuts with amounts at this point.

Add the 6z RGEM to the "bomb" potential in terms of snow amounts

[A-L-E-K]

looks like the 0z-6z runs were p awful for Chicago.

[Gilbertfly]

D2 via HPC...

 

[Stevo6899]

D2 via HPC...

day2_composite.gif

They update those in the middle of the night? Seems a bit north in MI.

[Gilbertfly]

D2 via HPC...

HPC collaborating with the watch/warning map???

[mimillman]

looks like the 0z-6z runs were p awful for Chicago.

Yep. Hoping 12z runs come in better, or they may want to consider an advisory instead. 2-5 still looks good.

[Chicago WX]

DVN has a good overnight AFD, a must read IMO. Even throwing out the word "bust" in response to where this thing eventually sets up.

 

THE SITUATION IS THIS...THE POTENTIAL FOR THE EVENT TO BUST ISGROWING RAPIDLY...BUT UNTIL WE KNOW THE EVOLUTION OF THIS SYSTEM FORCERTAIN...WE CANNOT RULE OUT...OR EVEN GREATLY DIMINISH THEPOTENTIAL FOR A HEAVY WET SNOW EVENT...ESPECIALLY IN THE SOUTHEAST1/2 OF THE CWA. SOMETIMES THERE IS NO CORRELATION BETWEEN AN EVENTSPOTENTIAL SIGNIFICANCE...AND THE CONFIDENCE THAT IT WILL OCCUR. AWATCH CONTINUES TO BE THE BEST PRODUCT TO REPRESENT THIS EVENT FOR

[Harry Perry]

looks like the 0z-6z runs were p awful for Chicago.

06z NAM was the best this cycle. Giving Chicago closer to 1" QPF.

06z GFS was less, with around .4" QPF, but it will bounce back and forth like this.

We already know this system is juicy. I have no doubt in my mind that the 06z NAM was closer to actual precip amounts, but with the temperatures at 32 and 33 degrees it's going to be a tough call.

 

[Harry Perry]

06z GFS has 2m temps around 33-34. What a hair puller.

[Chicago WX]

looks like the 0z-6z runs were p awful for Chicago.

 

You mean Milwaukee.

 

Good thing for Chicago was the 0z Euro had its best run to date for you all. Such a fluid situation...in that hitching your wagon to any one solution is precarious right now.

[A-L-E-K]

You mean Milwaukee.

 

Good thing for Chicago was the 0z Euro had its best run to date for you all. Such a fluid situation...in that hitching your wagon to any one solution is precarious right now.

 

 

I've locked in my final call (4.8)...but not feeling too great about it (p sure I glossed over the temp issues) this has all the makings up a quick 1-3" of quick hitting cement followed by 6-12 hours of additional light to moderate snow with little to no accums. We're going to need the main band to really rip because I don't think there is any avoiding major temp issues.

[Harry Perry]

Yep. Hoping 12z runs come in better, or they may want to consider an advisory instead. 2-5 still looks good.

I'm willing to bet that Chicago will be on the higher end of an advisory.

If dynamic cooling can cool the 850's enough it will snow at 33... something to keep in mind.

I really wish it was as cold as it was this morning for this event... 11 degrees over here.

[Chicago WX]

It's performance in question this winter, so buyer beware, but the 6z run of the RGEM pretty much shuts out the DVN CWA. MKE...not pretty. RFD, yikes. Gets 0.30" and change to Alek, but amounts drop considerably as you move west from his estate. 

[A-L-E-K]

I'm willing to bet that Chicago will be on the higher end of an advisory.

If dynamic cooling can cool the 850's enough it will snow at 33... something to keep in mind.

I really wish it was as cold as it was this morning for this event... 11 degrees over here.

 

I've seen nice fat flakes falling at a good rate not accumulate one bit because of warm surface temps.  I'm concerned about mixing but sub 5:1 ratios is a greater concern.  Unless the wettest models verfiy...this has major bust potential.

[A-L-E-K]

It's performance in question this winter, so buyer beware, but the 6z run of the RGEM pretty much shuts out the DVN CWA. MKE...not pretty. RFD, yikes. Gets 0.30" and change to Alek, but amounts drop considerably as you move west from his estate. 

 

Of all the models that will make me worry, the RGEM and a miss south just isn't going to cut it.  I'm shook but not that shook

[Chicago WX]

I've locked in my final call (4.8)...but not feeling too great about it (p sure I glossed over the temp issues) this has all the makings up a quick 1-3" of quick hitting cement followed by 6-12 hours of additional light to moderate snow with little to no accums. We're going to need the main band to really rip because I don't think there is any avoiding major temp issues.

 

Temp issues are the thing, even if snow is the predominant precipitation type. I'd lean lower because of that, no doubt about it. But like you said, intensity will be critical. Hopefully there are some good surprises in store for some, because there'll most likely be some bad surprises for a few.