Winter Storm March 1st-2nd (Part 2)

[TugHillMatt]

Hey Geos, if you could fill me on what the EURO shows qpf or snowfall wise for Toronto when it gets there, I'd appreciate it. Gotta split soon.

Come on. You know Geos will. He is the man!

[Geos]

Hey Geos, if you could fill me on what the EURO shows qpf or snowfall wise for Toronto when it gets there, I'd appreciate it. Gotta split soon.

 

0.67" of moisture through hour 48.

 

9-10" of snow.

First map.

 

[Geos]

NE sector.

 

[Hoosier]

AREA FORECAST DISCUSSION  

NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL  

1144 AM CST MON FEB 29 2016  

   

UPDATE  

 

1144 AM CST  

 

NO CHANGES TO HEADLINES THIS MORNING. HOWEVER...THERE ARE A FEW  

ITEMS OF NOTE AND CONCERN IN THE FORECAST PROCESS. AN EXTREMELY  

TIGHT THERMAL GRADIENT IS IN PLACE FROM THE LOCAL AREA TO THE  

UPPER MIDWEST...WITH 850 MB TEMP ON 12Z RAOB RANGING FROM +2  

CELSIUS AT ILX TO -25 CELSIUS AT INTERNATIONAL FALLS. SURFACE COLD  

FRONT IS MAKING QUICK HEADWAY SOUTHWARD AND HAS PASSED THROUGH  

THE WISCONSIN DELLS AREA. STARTING TO SEE SOME LIGHT ECHOES ON  

REGIONAL RADAR OVER NORTHERN IOWA...LIKELY IN RESPONSE TO  

DEVELOPING 925 MB FGEN. THE BIG QUESTION TONIGHT REMAINS HOW FAR  

SOUTH THE 850 MB FRONT GETS BEFORE WARM ADVECTION IN RESPONSE TO  

APPROACHING WAVE FROM THE PLAINS OCCURS. THIS WILL DICTATE  

PLACEMENT OF WHAT WILL BECOME A NARROW AND INTENSE 850 MB  

FRONTOGENESIS AXIS ACROSS SOUTHERN WISCONSIN AND NORTHERN  

ILLINOIS OVERNIGHT INTO EARLY TUESDAY. STEEP LAPSE  

RATES...NEGATIVE EPV ABOVE THE FGEN AND ABOVE NORMAL PWAT VALUES  

ALSO ARGUE FOR HEAVY PRECIP RATES. GUIDANCE VARIES FROM FARTHER  

NORTH 12KM NAM AND NMM TO LATEST RAP AND LOCAL WRF MODEL FARTHER  

SOUTH. GIVEN THE INTENSITY OF THE FGEN RESPONSE TO THE TIGHT  

THERMAL GRADIENT...SUSPECT THAT QPF VALUES COULD BE A BIT  

UNDERDONE IN MUCH OF THE GUIDANCE WHERE THE BAND SETS UP.  

 

CONCEPTUALLY...THIS SETUP CONTINUES TO FAVOR A VERY INTENSE BAND  

OF PRECIP AND A SHARP CUTOFF SOUTH OF IT DUE TO SUBSIDENCE.  

DEPENDING ON HOW QUICKLY LOWER LEVEL MOISTENING OCCURS THIS  

EVENING...PRECIP COULD BREAK OUT IN RESPONSE TO STRONG 925 MB FGEN  

WITH POSSIBLE PTYPE ISSUES. HOWEVER...ONCE 850 MB FGEN BAND  

BECOMES DOMINANT...SUSPECT THAT IT WILL BE MORE OF A HEAVY SNOW OR  

SO SCENARIO WITH POSSIBLY SOME LIGHT SLEET SOUTH OF THE BAND AS  

925 MB LEVEL GETS QUITE COLD. BECOMING LESS CONCERNED OVERALL WITH  

ANY SIGNIFICANT ICE ACCUMS FOR REASONS ABOVE AND ALSO VERY WARM  

PAVEMENT TEMPS IN MID TO UPPER 40S. SNOWFALL ACCUMS OF 4 TO 6  

INCHES MENTIONED IN THE WSW PRODUCT FOR NORTHERN TIER OF COUNTIES  

APPEAR TO BE EASILY ATTAINABLE GIVEN NEARLY STATIONARY PRECIP BAND  

OVERNIGHT. I'M WORRIED 6"+ AMOUNTS COULD BE MORE THAN  

ISOLATED. ALSO CONCERNED THAT FGEN BAND COULD SAG FAR ENOUGH SOUTH  

TO BRING HEAVIER SNOW TO AREAS NORTH OF I-88 CURRENTLY IN ADVISORY  

BUT NOT ENOUGH CONFIDENCE YET TO INCLUDE THEM IN WARNING. IF HEAVY  

SNOW BAND DOES INDEED END UP CONFINED TO FAR NORTHERN COUNTIES AND  

INTO SOUTHERN WI OVERNIGHT...MAIN PERIOD OF CONCERN FOR POINTS  

SOUTH INCLUDING CHICAGO FOR A FEW INCHES OF SNOW ACCUMS WOULD BE  

ROUGHLY THROUGH MID MORNING TUESDAY. THIS WOULD BE AS NEXT STRONG  

MIDLEVEL WAVE MOVES ACROSS THE AREA...MAINTAINING FAIRLY STRONG  

FGEN AS DEFORMATION AXIS FORMS ON NORTHWEST SIDE OF DEVELOPING  

SURFACE LOW.  

 

WILL CONTINUE TO MONITOR OBSERVATIONAL TRENDS AND MAKE A DECISION  

ON ANY HEADLINE CHANGES WITH AFTERNOON FORECAST PACKAGE.  

 

RC  

[hlcater]

0.67" of moisture through hour 48.

 

9-10" of snow.

First map.

 

Me gusta. That map is a bit nicer to those of the south end. Particularly out west. But also isn't as amped as NAM/GGEM/GFS

[cyclone77]

Can definitely pick out where the cold front is in Michigan.

 

[snowstormcanuck]

NE sector.

12zEURO_022916NE.png

Thanks Geos. Looks like the drier models are the way to go. Still should be a nice storm.

[SchaumburgStormer]

AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL  
1144 AM CST MON FEB 29 2016  
   
UPDATE  
  
1144 AM CST  
  
NO CHANGES TO HEADLINES THIS MORNING. HOWEVER...THERE ARE A FEW  
ITEMS OF NOTE AND CONCERN IN THE FORECAST PROCESS. AN EXTREMELY  
TIGHT THERMAL GRADIENT IS IN PLACE FROM THE LOCAL AREA TO THE  
UPPER MIDWEST...WITH 850 MB TEMP ON 12Z RAOB RANGING FROM +2  
CELSIUS AT ILX TO -25 CELSIUS AT INTERNATIONAL FALLS. SURFACE COLD  
FRONT IS MAKING QUICK HEADWAY SOUTHWARD AND HAS PASSED THROUGH  
THE WISCONSIN DELLS AREA. STARTING TO SEE SOME LIGHT ECHOES ON  
REGIONAL RADAR OVER NORTHERN IOWA...LIKELY IN RESPONSE TO  
DEVELOPING 925 MB FGEN. THE BIG QUESTION TONIGHT REMAINS HOW FAR  
SOUTH THE 850 MB FRONT GETS BEFORE WARM ADVECTION IN RESPONSE TO  
APPROACHING WAVE FROM THE PLAINS OCCURS. THIS WILL DICTATE  
PLACEMENT OF WHAT WILL BECOME A NARROW AND INTENSE 850 MB  
FRONTOGENESIS AXIS ACROSS SOUTHERN WISCONSIN AND NORTHERN  
ILLINOIS OVERNIGHT INTO EARLY TUESDAY. STEEP LAPSE  
RATES...NEGATIVE EPV ABOVE THE FGEN AND ABOVE NORMAL PWAT VALUES  
ALSO ARGUE FOR HEAVY PRECIP RATES. GUIDANCE VARIES FROM FARTHER  
NORTH 12KM NAM AND NMM TO LATEST RAP AND LOCAL WRF MODEL FARTHER  
SOUTH. GIVEN THE INTENSITY OF THE FGEN RESPONSE TO THE TIGHT  
THERMAL GRADIENT...SUSPECT THAT QPF VALUES COULD BE A BIT  
UNDERDONE IN MUCH OF THE GUIDANCE WHERE THE BAND SETS UP.  
  
CONCEPTUALLY...THIS SETUP CONTINUES TO FAVOR A VERY INTENSE BAND  
OF PRECIP AND A SHARP CUTOFF SOUTH OF IT DUE TO SUBSIDENCE.  
DEPENDING ON HOW QUICKLY LOWER LEVEL MOISTENING OCCURS THIS  
EVENING...PRECIP COULD BREAK OUT IN RESPONSE TO STRONG 925 MB FGEN  
WITH POSSIBLE PTYPE ISSUES. HOWEVER...ONCE 850 MB FGEN BAND  
BECOMES DOMINANT...SUSPECT THAT IT WILL BE MORE OF A HEAVY SNOW OR  
SO SCENARIO WITH POSSIBLY SOME LIGHT SLEET SOUTH OF THE BAND AS  
925 MB LEVEL GETS QUITE COLD. BECOMING LESS CONCERNED OVERALL WITH  
ANY SIGNIFICANT ICE ACCUMS FOR REASONS ABOVE AND ALSO VERY WARM  
PAVEMENT TEMPS IN MID TO UPPER 40S. SNOWFALL ACCUMS OF 4 TO 6  
INCHES MENTIONED IN THE WSW PRODUCT FOR NORTHERN TIER OF COUNTIES  
APPEAR TO BE EASILY ATTAINABLE GIVEN NEARLY STATIONARY PRECIP BAND  
OVERNIGHT. I'M WORRIED 6"+ AMOUNTS COULD BE MORE THAN  
ISOLATED. ALSO CONCERNED THAT FGEN BAND COULD SAG FAR ENOUGH SOUTH  
TO BRING HEAVIER SNOW TO AREAS NORTH OF I-88 CURRENTLY IN ADVISORY  
BUT NOT ENOUGH CONFIDENCE YET TO INCLUDE THEM IN WARNING. IF HEAVY  
SNOW BAND DOES INDEED END UP CONFINED TO FAR NORTHERN COUNTIES AND  
INTO SOUTHERN WI OVERNIGHT...MAIN PERIOD OF CONCERN FOR POINTS  
SOUTH INCLUDING CHICAGO FOR A FEW INCHES OF SNOW ACCUMS WOULD BE  
ROUGHLY THROUGH MID MORNING TUESDAY. THIS WOULD BE AS NEXT STRONG  
MIDLEVEL WAVE MOVES ACROSS THE AREA...MAINTAINING FAIRLY STRONG  
FGEN AS DEFORMATION AXIS FORMS ON NORTHWEST SIDE OF DEVELOPING  
SURFACE LOW.  
  
WILL CONTINUE TO MONITOR OBSERVATIONAL TRENDS AND MAKE A DECISION  
ON ANY HEADLINE CHANGES WITH AFTERNOON FORECAST PACKAGE.  
  
RC  

He's throwing us southern folks a bone, lol

[A-L-E-K]

HRRR continues to bump north with the FGEN, there is very little support remaining for those further south so i wouldn't get your hopes up

 

[dmc76]

3.2 over and under for ORD is gonna be a close one!

[Louieloy102]

3.2 over and under for ORD is gonna be a close one!

Would take the under barely there. These gradients seem to never favor the ORD area.

[Chicago Storm]

3.2 over and under for ORD is gonna be a close one!

Easy under.

[Geos]

Like RC said you can already see the f-gen band getting ready to develop along US 20 in Iowa. 

For the record, the HRRR kept on moving the snow NW during that last storm, but that didn't happen.

 

RPM likes south.

 

[A-L-E-K]

Easy under.

 

 

yep

[Chinook]

Can definitely pick out where the cold front is in Michigan.

 

 

Wind gust to 56mph near Alpena MI with moderate snow in the area. There must have been quite the blowing snow.

[A-L-E-K]

Like RC said you can already see the f-gen band getting ready to develop along US 20 in Iowa. 

For the record, the HRRR kept on moving the snow NW during that last storm, but that didn't happen.

 

RPM likes south.

 

rpm022916.png

 

 

bustn' a nut face on that screen cap

[snowstormcanuck]

Like RC said you can already see the f-gen band getting ready to develop along US 20 in Iowa. 

For the record, the HRRR kept on moving the snow NW during that last storm, but that didn't happen.

 

RPM likes south.

 

rpm022916.png

 

lol his face screams confidence.

[snowstormcanuck]

I'm going to bump my range for Toronto a little to 6-9". Won't lock it in since we still got 24 hours to go before the first flakes fly.

[Geos]

bustn' a nut face on that screen cap

 

 

lol his face screams confidence.

 

He was making the face while saying the morning rush hour will be a mess. lol

 

Front is entering the northern burbs of MKE now.

[Hoosier]

Like RC said you can already see the f-gen band getting ready to develop along US 20 in Iowa. 

For the record, the HRRR kept on moving the snow NW during that last storm, but that didn't happen.

 

RPM likes south.

 

rpm022916.png

 

 

That's the updated run?

[Geos]

That's the updated run?

 

Yeah. It is a bit south of the last few runs. 

 

This was 10am

 

[Thundersnow12]

bustn' a nut face on that screen cap

 

probably my least favorite WGN met, always posing weird and horribly off snowfall maps 

[Baum]

I have a hard time ever remembering a decent frontogenic event south of ORD. They are almost always transient and end up stalling and dumping over S. Wisconsin. No meteorology just history.

Edit: I'm riding the RPM

[Roger Smith]

Toronto 12-18 cm, London 10-15, Kingston 15-20, Ottawa 20-25 would be my estimates.

 

Generally agree with the discussion I've read above, 8-12 inch storm for a zone centred on MKE-GRR-FNT, 5-10 potential for Chicago but with the mixing issues and tight gradient, could be more or less in some areas. Only looks like 1-3 inches for DTW to me, trending gradually up to 5-8 around PTK and 6-10 LAN.

[A-L-E-K]

I have a hard time ever remembering a decent frontogenic event south of ORD. They are almost always transient and end up stalling and dumping over S. Wisconsin. No meteorology just history.

Edit: I'm riding the RPM

 

 

i'm due east of ORD and couple winters back an fgen band played a huge part of a 19" marathon event IMBY

 

EDIT: i'm riding the euro

[snowstormcanuck]

GEFS ensemble QPF. Looks like the average would be at or a little below 0.75" at YYZ. A few sub 0.50"s, a few ~1.00"s.

 

[Geos]

I have a hard time ever remembering a decent frontogenic event south of ORD. They are almost always transient and end up stalling and dumping over S. Wisconsin. No meteorology just history.

Edit: I'm riding the RPM

 

Yeah I can't remember a time either. Seen some pretty good ones hit far northern Cook before.

 

GFS is the most accurate with the front so far, but even it is lagging time wise. 

[snowcaine]

Thinking 8-12" for Toronto. Really depends if a nice deformation band sets up or not.

There should be some Lake enhancement as well.

[Hoosier]

Yeah I can't remember a time either. Seen some pretty good ones hit far northern Cook before.

 

GFS is the most accurate with the front so far, but even it is lagging time wise. 

 

 

Check April 10-11, 1997 if you want a good one south of Chicago.  I'm sure there are more recent good examples.

[snowstormcanuck]

Thinking 8-12" for Toronto. Really depends if a nice deformation band sets up or not.

There should be some Lake enhancement as well.

 

You know, I haven't even looked into that. Cursory look suggests it'd be cold enough, at least initially.

 

Mesoscale models off of BUF's website not indicating much. Guessing inversion heights are too low or airmass is too dry. Still something to keep an eye on.