2/25/08-2/26/08 WINTER STORM FCST: NE/KS/MN/IA/MO/WI/IL/MI/IN/OH

[Joel Wright]

Well, you can tell everyone's getting really sick of snow and winter lol. No one's started a thread on this yet. The only reason I am is because I'm bored...

Anyway, looks like yet another snowstorm on the way for much of the midwest. The average track by the models takes it from northern KS, through northern MO, through central IL, and into central IN. This would place the band of heaviest snow from east-central/northeast NE, through about the northern 3/4 of IA, through northern IL/IN, and eventually into southern lower MI. This track has been uncharacteristically trending further south with each model run. This is somewhat confusing since almost every other storm this season has trended further north each run. Kind of makes me wonder how accurate these forecasts are.

This storm looks like it'll be pretty vigorous, so there'll likely be some bands of very heavy snow. Especially after the deeper gulf moisture gets tapped by tomorrow night. Someone along the I-80 corridor may get over 8" with this thing.

 

[rdale]

It's not as much a "trend" as it is "how hard is the butterfly flapping"

SREF shows incredible disagreement, which at this timeframe is not good news...

Take a look at lows from the latest run, then mouseover to see how dramatically it's changed for valid Tuesday morning! http://www.spc.noaa.gov/exper/sref/...e=2008022421&field=SREF_Spaghetti_Low_Centers__

 

[Jim Zandonai]

Yeah its another storm..sighhh.. Well my 'sighing' takes nothing away from the potency of this storm but for all of you not living in this area we are definitely tired of snow..period. We still have 6-8" on the ground and the thought of pushing us back to a foot again is crushing ! Okay anyway this storm has been more south destined so it looks like the heaviest snow band should be across East IA and N .IL. What looked liked rain in I-80 area may be a heavier snow event then previously expected.. This should be wet heavy snow too.. I'll post some now reports if anything significant comes about..
It will feel good..really good to be talking about thunder again up here which cannot come soon enough.. I must admit though it has not been a boring Winter but to see the grass again will be sight for sore eyes !

 

[Joel Wright]

... http://www.spc.noaa.gov/exper/sref/...2008022421&field=SREF_Spaghetti_Low_Centers__

The link isn't working for me for some reason.

Edit: Nevermind, working now!

Yep, definitely some major differences there. Kind of scary since the storm is less than 24hrs away...

 

[rdale]

I went against the high numbers after seeing the GFS -- 2" for Lansing, 4" for Jackson, little bit more south of I94.

 

[Bill Schintler]

FCST winter storm, eastern IA

A powerful winter storm will a mixture of freezing rain, rain, heavy snow, and strong winds to the area beginning Monday morning:

Cedar Rapids:
Freezing rain will start at 8:00 AM and accumulate to 0.1 inches of ice before a transition to rain at 11 AM. Rain will change to snow at 2 PM, and snow will accumulate to 6.5 inches before ending after midnight as north winds increase to 25 mph and gust to 35 mph.

Iowa City:
Freezing rain will start at 8:30 AM and accumulate to 0.08 inches of ice before a transition to rain at 10:30 AM. Rain will change to snow at 2:30 PM and isolated lightning and thunder will be possible during the afternoon. Snow will accumulate to 6.1 inches before ending after midnight as north winds increase to 25 mph and gust to 35 mph. If thundersnow develops, locally enhanced snowfall rates will result.

Marengo:
Freezing rain will start at 8:15 AM and accumulate to 0.07 inches of ice before a transition to rain at 10:15 AM. Rain will change to snow at 2:15 PM and isolated lightning and thunder will be possible in the afternoon. Snow will accumulate to 6.2 inches before ending after midnight as north winds increase to 25 mph and gust to 35 mph. If thundersnow develops, locally enhanced snowfall rates will result.

Paris/Coggon:
Freezing rain will start at 8 AM and accumulate to 0.11 inches of ice before a transition to rain at 11:15 AM. Rain will change to snow at 2:00 PM, and snow will accumulate to 6.1 inches before ending after midnight as north winds increase to 25 mph and gust to 35 mph.

Synopsis:
UA analysis indicated WRN CONUS trough with associated height falls concentrated over the Four Corners area. At the SFC, low pressure was organizing over NERN CO with an associated pressure fall bull’s-eye over North Platte, NE. Precipitation was underway in South Dakota in a zone of isentropic up glide along the 295K-300K SFCS. Closer to home, temperatures have risen above freezing in response to strong WAA which has also resulted in air stagnation beneath the inversion. The GFS has the best handle of the strength and position of the SFC system while the NAM is too fast with the timing.

Discussion:
During the day Monday, SFC low pressure will track from near Garden City, KS (12Z) to Emporia, KS (18Z) and into MO along I-70 during the afternoon hours while slowly strengthening. The 850mb low will follow a track about 50 miles N of I-70. The NAM has favored a slower and more NRLY track late in the period; while all models in general have indicated an increasingly SRLY trend in the storm track. This, of course, has important implications in the type and amount of precipitation that falls during this mixed-precipitation event. During the first half of the day, impressive isentropic lift will develop E of the low; with top-down saturation, moderate evaporational cooling, and precipitation onset between 13Z and 17Z in ERN IA. Precipitation will start as freezing rain, with a change to rain by 18Z with strong WAA. After 18Z, a combination of cold advective processes and rapid evaporational cooling will result in a change to all snow. Snow growth and snow/water ratios increase dramatically during the early evening as strong CAA in the H8-H6 layers is collocated with very strong lift as the H5 vort max approaches and a deformation zone strengthens along I-80.

After 09Z, lift moves E of the area while winds will increase out of the N. Strong CAA in the H85 layer will increase LLVL lapse rates, allowing for downward momentum transfer of a 50kt LLJ. Looking ahead, a clipper system will bring a shot of WAA and precipitation in the Thursday to Friday timeframe.

- bill
11:00 PM, 02/24/08

 

[rdale]

I went against the high numbers after seeing the GFS -- 2" for Lansing, 4" for Jackson, little bit more south of I94.

Final tally - 2.2" in Lansing, 3.7" in Jackson...

 

[Joel Wright]

Only got a bit over 3" here (Now brings me to 57" for the season). I think most areas around got about the same. The models decreased QPF the last few runs before the storm hit. Overall, pretty much a non-event.

This was very wet snow. I think ratios were less than 10:1 snow to water.

 

[rdale]

NAM and GFS actually went the other way for us, each upping into the 4-6" range, which is why I think NWS raised their numbers too high as well...

We were probably right at 10:1 here.