2-17 Lower Lakes Winter Storm

[Tom]

3-4 days ago models had nothing going for N IL and this was looking like a WI/MI event.  Now the trend the past 2 days is colder and farther south with the accumulating snow.  I'd bet money that it will be all snow from I-80 on north.

[james1976]

wow, NAM looks impressive.

[Geos]

Much of that is iffy.  Right now I'd say 3-5" in N Illinois, maybe isolated 6" with some sleet and freezing rain mixed in, not quite as pessimistic as Geos.

 

After I saw the soundings on the NAM a little while ago, I think it's a good call.

[Tom]

00z GGEM coming in cold also...no problems with mixing over here.

 

 

[Tom]

GGEM actually coming in pretty wet like the NAM...let's see what the Euro shows....

 

[Sciascia]

Saw someone elsewhere say that the latest UKMET has a good snow for the Chicago area.

[Money]

ECMWF has a 1006 L in C/N Indiana at HR 72

[Money]

UKMET HR 72: 999 L E/C IL. Chicago gets crushed. Looks a lot like the 0z GGEM from last night.

[Tom]

00z Euro also colder...I see no problems with mixing with the full suite of 00z runs.

 

[Money]

Looking good for about 3-5/4-6 here. 

 

GFS is pretty clueless tbh. In the big eastcoast system it had DC getting 4-6 inches within 24 hours of the event. Some places got 20+

[Tom]

Believe it or not, 00z Euro has ORD temps in the low 20's for the duration of this event.  Same goes with the 00z GGEM.  We may have a similar situation happen as we did a week or two ago when 850's were around -4C or so and ground temps in the mid 20's that created big snow flakes.  Snow ratios wont be higher than I'd say 12:1 or 13:1 with this event as it stands.

[abhidupage]

This is what UKMET 00z showed probably overdone but would be really impressive with snow falling beyond that hr. This is precip accumulated in 12 hr period.

[Tom]

This storm is turning out to be a system that phases and intensifies like this off the east coast.  We are in the 48-54 HR period and surprisingly a majority of the models are showing ample moisture supply with this system.  With the placement of the jet stream over head in the "left front exit" region this is an ideal set up for lift and snow production.

[Money]

HR 72 pos. for each model:

 

GFS: 1012? L on the IN/OH border

UKMET: 999 E/C IL

ECMWF: 1004 C/N IN

GGEM: 1010 E IN

NAM: 1003 NE IN

[Yerf]

Strong wording from LOT. Colder and a ton of moisture

[Money]

WAVE AND SNOWFALL EXIT THE CWA OVERNIGHT TONIGHT WITH SURFACE
RIDGE AXIS BUILDING ACROSS THE REGION INTO SUNDAY...BRINGING A
PERIOD OF QUIET WEATHER INTO SUNDAY EVENING. GUIDANCE HAS ALMOST
DONE A 180 FROM THE PREVIOUS NIGHT...WITH SUNDAY NIGHT INTO
MONDAYS WEATHER PATTERN APPEARING TO BE MUCH COLDER WITH FROZEN
PRECIPITATION BECOMING MORE LIKELY AND ANY RAIN BECOMING LESS
LIKELY...EVEN ACROSS THE SOUTHERN CWA ON MONDAY. GUIDANCE IN FAIR
AGREEMENT WITH GENERAL PATTERN SUNDAY NIGHT INTO MONDAY AND WITH
RESPECT TO TIMING...WITH A DELAY IN PRECIP EXPECTED ONCE AGAIN.
MID/UPPER LEVEL TROUGH PROGGED TO SWING ACROSS THE CENTRAL CONUS
LATE SUNDAY NIGHT INTO MONDAY WITH SURFACE REFLECTION SHIFTING
EAST TOWARDS THE MID MISSISSIPPI VALLEY. HAVE LOWERED POPS FOR
SUNDAY NIGHT WITH ANY PRECIP NOW EXPECTED TO REMAIN WEST OF THE
CWA. ALTHOUGH WITH STRONG ISENTROPIC ASCENT OUT AHEAD OF THIS
TROUGH...DID MAINTAIN A SLIGHT CHANCE MAINLY FOR THE NORTHWEST
CWA. PRECIP SHOULD REMAIN SNOW IF IT WERE TO FALL DURING THIS
PERIOD...BUT WITH THE ANTICIPATED STRONG WAA STARTING TO CAUSE
ISSUES WITH PRECIP TYPE MAINLY FOR WESTERN ILLINOIS. ALTHOUGH THE
GENERAL IDEA REMAINS FOR MONDAY WITH A VIGOROUS MID LEVEL TROUGH
TO SWING ACROSS THE CWA...THERMAL PROFILES STILL DIFFER SLIGHTLY.
HAVE GONE WITH MORE OF A ECMWF/NAM/SREF TREND IN TERMS OF THE
THERMAL PROFILES...WITH A CONSISTENT SIGNAL OF SOME WARMING IN THE
COLUMN LIKELY OCCURRING MAINLY FOR THE SOUTHERN HALF OF THE CWA
MONDAY MORNING. THIS WILL LIKELY OCCUR AS PRECIP AXIS SHIFTS EAST
WITH A PERIOD OF FREEZING RAIN/SNOW/SLEET POSSIBLE ACROSS THIS
AREA. DETAILS WILL LIKELY NEED TO BE REFINED WITH TIME BUT WITH A
WINTRY MIX LIKELY IN THIS AREA...AND ALL SNOW LIKELY FURTHER
NORTH. AS QUICK AS THIS WARMING OCCURS...COLDER AIR ALOFT SHOULD
DROP BACK SOUTH HELPING TO PROVIDE A SETUP MORE INDICATIVE OF ALL
SNOW THROUGHOUT THE ENTIRE CWA. THIS TRANSITION COULD COME AS SOON
AS MID DAY MONDAY ESPECIALLY WITH STRONG LARGE SCALE FORCING
HELPING TO COOL THE COLUMN. OUTSIDE OF A SMALL AREA ACROSS THE
SOUTHEAST CWA...ALL SNOW COULD BE LIKELY OBSERVED IN THE
AFTERNOON. OF COURSE THIS IS STILL A COUPLE OF DAYS AWAY AND THE
PATTERN COULD CHANGE. ALTHOUGH AT THIS TIME...ONCE AGAIN...A
COLDER TREND IS APPEARING MORE LIKELY. THIS SYSTEM/EVENT CONTINUES
WORTH MONITORING AS THIS COULD BE A STRONG SYSTEM WITH MANY
ASPECTS WORKING FOR IT...STRONG FORCING/ABUNDANT MOISTURE/STEEP
LAPSE RATES. ALL OF THIS IS POINTING TOWARDS THE POSSIBILITY FOR
SIGNIFICANT PRECIP MONDAY...WHETHER IT BE ALL SNOW OR A WINTRY
MIX.

[Scott26]

Does anyone know what happened to the 12Z NAM this morning? It's not up on instantweathermaps and I can't get the text data for it on accuweather pro. Did it not run yet?

[Sciascia]

Does anyone know what happened to the 12Z NAM this morning? It's not up on instantweathermaps and I can't get the text data for it on accuweather pro. Did it not run yet?

InstantWeatherMaps isn't running the 12z GFS right now either. Talk about bad timing.

[abhidupage]

InstantWeatherMaps isn't running the 12z GFS right now either. Talk about bad timing.

 

Yeah Nam 12z has been delayed idk how much 12z gfs will be affected by the delay in terms of the time it comes out.

[DominicR]

NOUS42 KWNO 151437

ADMNFD

SENIOR DUTY METEOROLOGIST NWS ADMINISTRATIVE MESSAGE

NWS NCEP CENTRAL OPERATIONS COLLEGE PARK MD

1433Z SAT FEB 15 2014

12Z MODEL PRODUCTION CYCLE DELAYED.. DUE TO THE MAJOR CIRCUIT AND

INTERNET SERVICE ISSUE AT THE TOC/GATEWAY.. FURTHER DELAY OF 2HRS

WE ARE STILL DELAYING THE START OF THE 12Z CYCLE RUNS.. . DUE TO

THE ON-GOING ISSUES AT THE GATEWAY/TOC. THEIR VENDOR/CONTRACTOR

SAYS

THEIR WORK COULD TAKE UP TO 2-3 HRS ADDITIONALLY... CURRENT

VENDOR ESTIMATES SHOW WORK MAY NOT BE COMPLETED FOR 2 MORE HRS..

SO AFTER 16Z..

WE WILL UPDATE YOU AS SOON AS WE KNOW HOW LONG THE DELAY OF THE

12Z MODELS WILL BE... MOST OF THE DATA NEEDED TO RUN THE MODELS

IS NOT REACHING THE NEW WCOSS SUPER COMPUTER TO RUN THE MODELS

AND WE ARE ALSO UNABLE TO SEND PRODUCTS OUT AS WELL TO

AWIPS...VIA THE TOC/GATEWAY.

MORE INFORMATION ONCE THIS BECOMES AVAILABLE..

NEWBY/SDM/NCO/NCEP

 

[The Snowman]

12z NAM and GFS are about to get going: http://www.nco.ncep.noaa.gov/pmb/nwprod/prodstat_new/

[Money]

GFS is starting up.

 

GGEM is out to hr 36.

[Money]

GGEM looks colder and a bit wetter? 

 

Hard to tell on B/W maps

 

12z HR 60:

 

http://weather.gc.ca/data/model_forecast/622_100.gif

 

0z HR 72

 

http://weather.gc.ca/data/model_forecast/492_100.gif

[Money]

GFS staying consistent with a weak low.

 

3-5 across WI/MN. 1-2 in N. IL

[Tony]

Someone on another forum just mentioned that the GFS has been the best model all winter. Am I missing something here as I do not see this as being true???

[East Dubzz]

Someone on another forum just mentioned that the GFS has been the best model all winter. Am I missing something here as I do not see this as being true???

Maybe it depends on what part of the U.S.

[Money]

ukmet stays consistent

 

http://www.americanwx.com/bb/uploads/monthly_02_2014/post-68-0-37941100-1392483138.gif

[Money]

NAM with .25-.5 QPF

[Tom]

12z NAM....

 

Edit:  NAM keeps 850's at ORD from -3C to -6C for the duration of the event.

[Money]

GGEM colored maps

 

http://weather.gc.ca/data/model_forecast/colour_images/12_054_G1_north@america@zoomout_I_4PAN_CLASSIC@012_060.jpg

 

Would probably be .25-.5 QPF

[Sciascia]

Maybe it depends on what part of the U.S.

The guy is claiming for this area. I didn't think it did too well at all in January. The NAM and/or Euro, to my recollection, pretty much nailed any decent to big snow event here in N IL.

[Tom]

12z GGEM takes SLP thru S IL/S IN...more realistic with QPF this run

 

[Money]

NAM: .5

GGEM: .4-.5

UKMET .5-.6

GFS: .3-.4

 

So, 12:1 ratios would be about 5-6 inches on most models for around S. WI and maybe 3-5 on the GFS. 

[Tom]

You guys remember that snowstorm that hit Japan last Saturday???  Well, its now going to be hitting our region Monday.  Isn't it fascinating that you can use non computerized tools or weather models to forecast a system 6-10 days (East Asian Theory) or even weeks and months in advance (LRC)?  Oh, and ya, Japan just got hit with another storm yesterday and that system is coming next weekend.  Amazing consistency using the east Asian theory.

[james1976]

The powerhouse storm at the end of the GFS run (hr 384)...is it part of the LRC?

[Tom]

Yes, it could very well be.  If you remember the Jan 4-5th storm that hit the Midwest and you extrapolate 57-58 days in advance, your looking at March 3-4th.  I expect a deeper trough end of Feb into March relevant to the pattern we saw in early January.

[Sciascia]

Euro maps? I saw that at 72hrs, the low was in NE MI.

[Tom]

12z Euro coming in colder and a little stronger from it's previous runs.  Almost deepening at a pace of 1mb an hour, but not quite.  850's at ORD are ideal at -5C or less for duration of the event and ground temps hovering in upper 10's to near 20F.  Same goes for IA/S WI.  Should have good snow ratios with this system.  0C line is down to Peoria, IL so more snow downstate Illinois.

[DominicR]

That nice D**n. Could be looking at low end warning snows if this keeps up and even some lake enhancement possibly.

[DominicR]

Everyone all worried about GFS. Seems to be Outlier right now.