2-19/2-21 Great Lakes Winter Storm...Heavy Rain/Flooding and Snow

[Money]

Discuss the storm for this upcoming week here. Models seem to be trending towards a pretty big storm that could provide some snow on the backside or some flooding rains in areas that have a lot of snowpack (latest GFS run showing 1.5+ qpf)

[Money]

0z GGEM HR 96

 

http://weather.gc.ca/data/model_forecast/134_100.gif

[Geos]

I just looked at the GFS is showing a possible major flood event for IL.

 

This would be a big problem.

 

 

...That could be a disaster! Street flooding, basement flooding, ice jams, you name it.

[Money]

ukie really bombs it out.

 

980 over msp at hr 96

[Money]

euro 985 in s. wi at hr 96

[Tom]

00z Euro...still lots of time to digest this system.  Floods over 1" rains in IA/IL/WI where it doesn't snow.

[East Dubzz]

Hmm... This one is gonna be interesting. And has potential cause some bad problems.

[Money]

NAM with 6+ across W. WI. Seriously think this storm is another one to watch. Trended farther SE from it's 0z/06z runs plus with the 4-6+ more inches of snowcover that would only likely enhance the colder temps

[Tom]

Will we see another SE shift in the storm track with this system like we did with the system we are currently getting by???  12z NAM showing a shift in the heavy rains farther south now.

[Tom]

Plus a deeper snowpack may also push the system farther south...that's something to keep in mind as systems occasionally like to ride to the south of the deepest snow pack.

[Money]

Yeah, and each run seems to have more cold sector qpf, should be a big mix of things here for now though. FZR/SN/RN etc

[East Dubzz]

The 12z NAM certainly looked interesting for over here.

[Money]

12z GFS: 980 over GB at HR 84.

 

12z NAM 990 over W. MI at HR 84

[Geos]

12z NAM still has 1"+ over NE IL.

Still coming in range.

 

EURO was back with low 50s in NE IL at 96 hours.

[Iowawx]

12Z GFS hour 78. Chicago gets quite a bit of rain.

[Money]

12z GGEM HR 84: 991 over MKE.

 

39+ MM of precip in the Chicago area

 

http://weather.gc.ca/data/model_forecast/233_100.gif

[Money]

btw 39 mm is about 1.53 QPF plus there was more at HR 72 and 96.

[Iowawx]

GGEM suggest snow on Thursday with the SLP near MKE. Hopefully a southern shift can occur otherwise it will be a real mess in Iowa. Chicago appears to be getting rain. 

[Tom]

This has a good possibility of being an IA/WI special as it did in Cycle 2...I was worried about that over here in Chicago over a week ago.  Didn't expect soo much rain though with this system.  We'll see how this system evolves are the coming days.

[james1976]

man the gfs looks perfect for me...as well as nam. hope it holds true.

[Money]

ukie has a 978 mb low in n. wi or so at hr 96. Hard to tell where it goes inbetween frames

[james1976]

this storm is looking stronger and stronger all the time.

[Money]

One thing you will have to watch out for is the flash freeze. All models have temps dropping quickly to 20 degrees or less.

 

For example. GFS has temps dropping from 31 here at hr 87 to 2 degrees by hr 96. 29 degree drop in 9 hours. 

[Money]

GFS has temps going from 44 at HR 81 to 24.7 at HR 90 with over 1.25 QPF of rain.

 

20 degree drop in 9 hours.

[Geos]

GGEM

I was hearing sandbags are being made up in northern IN already.

 

[Jaycee]

GGEM

I was hearing sandbags are being made up in northern IN already.

 

http://www.americanwx.com/bb/uploads/monthly_02_2014/post-7389-0-30096300-1392660320.jpg

Holy cow. Talk about an idle track. That'd be incredible if that panned out. I'm getting way jealous of you guys, we need this storm. I haven't seen anything but pea sized flakes fall for an extended period of time this year. This first frame would be a hell of a snowstorm with heavy rates if it panned out.

 

EDIT: Not sure what the temps would look like, but GFS has a freezing rain event. Yuck.

[Iowawx]

This storm is going to have to go south to give us snow in Eastern Iowa. Chicago looks like rain for the entire event. Any promising signs of a southern shift?? 

[Money]

geos how does the qpf look on the euro?

[Tony]

Just a quick glance it looks like Euro went south

[East Dubzz]

Brings the SLP right through the Dubuque area.

[Geos]

Holy cow. Talk about an idle track. That'd be incredible if that panned out. I'm getting way jealous of you guys, we need this storm. I haven't seen anything but pea sized flakes fall for an extended period of time this year. This first frame would be a hell of a snowstorm with heavy rates if it panned out.

 

EDIT: Not sure what the temps would look like, but GFS has a freezing rain event. Yuck.

 

That's all rain for this area. Going to be a mess.

[Geos]

geos how does the qpf look on the euro?

 

For this storm, for Milwaukee it sends out: 0.32" of liquid. Much heavier down this way.

 

Milwaukee gets to 50°.

[Money]

LSE buried on the 18z nam. 8-10+ 

 

Takes a 985 L pretty much right over head here like the euro

[Iowawx]

This storm needs to go south to give us snow, and not have Chicago flood. Any signs of a southern shift? 

[Tom]

18Z NAM...if it does rain, it wouldn't be that bad according to the NAM.  Maybe .40-.50 qpf at ORD.

 

 

[Money]

Pretty mixed bag on the 12z GFS ensembles. Several with a storm south of Chicago, others looking like the euro/nam etc

 

http://www.meteo.psu.edu/ewall/ENSPRSNE_12z/f84.html

[Money]

18z GFS is colder and a bit farther SE than 12z. Even brings a couple inches here (2-4)

[Geos]

Quite a few wet ensembles over the snow pack areas.

 

[Snowshoe]

18Z NAM...if it does rain, it wouldn't be that bad according to the NAM.  Maybe .40-.50 qpf at ORD.

 

Right in the bulls eye!

[Money]

GB AFD

 

MODELS HAVE COME INTO BETTER AGREEMENT WITH THE SYSTEM TO AFFECT
THE REGION LATE WEDS NGT INTO THURSDAY NIGHT. YESTERDAY...THE MODELS
WERE INDICATING THAT THE UPPER LOW MOVG THROUGH SOUTHERN CANADA
AND THE S/W TROF LIFTING NE OUT OF THE OKLAHOMA PANHANDLE WOULD
NOT EFFECTIVELY PHASE...WITH THE BETTER FORCING AND PCPN SPLITTING
NORTH AND SOUTH OF NE WI. THE MODELS HAVE CHANGED THEIR TUNE...AND
ARE PHASING THE SYSTEMS ON THU/THU NGT...RESULTING IN A DEEPER SFC
LOW THAT TRACKS FARTHER NW (THROUGH SE WI/LAKE MICHIGAN AREA) THAN
PREVIOUSLY THOUGHT. THIS IS ACTUALLY CLOSER TO WHAT THE ECMWF WAS
FORECASTING SEVERAL DAYS AGO...SO THE TREND IS NOT TOO SURPRISING.
BASED ON THE LATEST RUNS...ITS EXPECTED THAT SOME LIGHT PCPN WILL
ARRIVE AFTER MIDNIGHT WEDS NGT/EARLY THU MORNING...WITH A WEAK
WARM LAYER FROM 925-850 MB SUPPORTING A WINTRY MIX OVER ALL BUT
THE FAR NORTH...WHERE SNOW SHOULD PREVAIL. AS THE SFC LOW LIFTS NE
INTO THE REGION ON THU/THU EVG...IT WILL PULL WARMER AIR AND GULF
MOISTURE INTO ABOUT THE SE HALF OF THE FCST AREA...LEADING TO
MIXED RAIN/SNOW...OR POSSIBLY ALL RAIN. FARTHER NW...MODERATE TO
HEAVY SNOW IS POSSIBLE...ESPECIALLY NW OF A LINE FROM ISW-IMT. THE
HEAVY SNOW SHOULD LIFT OUT OF NORTH CENTRAL/FAR NE WI THURSDAY
EVENING. OF COURSE...ALL OF THIS DEPENDS ON THE EVENTUAL TRACK OF
THE SYSTEM...WHICH COULD CHANGE DRASTICALLY WITH SUBSEQUENT MODEL
RUNS...GIVEN THE DIFFICULTY THAT MODELS TYPICALLY HAVE WITH
PHASING SYSTEMS.

 

MKE AFD 

 

FOR WED NT THROUGH THU NT...STRONG CYCLOGENESIS IS NOW DEPICTED ON
THE MODELS FROM THE CENTRAL PLAINS THROUGH ERN WI AS A POLAR
TROUGH DIGS INTO THE PLAINS AND THEN LIFTS INTO THE GREAT LAKES.
WIDESPREAD MIXED PCPN IS EXPECTED BEGINNING LATE WED NT WITH
MAINLY FREEZING RAIN AND SLEET...SOME SNOW POSSIBLY IN THE NRN
CWA. ICE ACCUMULATION IS EXPECTED. THIS MIXED PCPN AND ICE ACCUM
WILL LINGER INTO THU AM. TEMPS WILL THEN BECOME WARM ENOUGH FOR
RAIN AT LEAST OVER THE ERN HALF OF THE CWA WITH A MIX OF RAIN AND
SNOW IN THE WEST. ANY SNOW ACCUMS ARE EXPECTED TO BE LIGHT UNLESS
THE LOW TRACKS FARTHER EAST. BRISK WINDS AND STRONG COLD ADVECTION
FOR THU NT INTO FRI AM.