March 7th-9th Potential Storm

[Moneyman]

Thanks, an all rain event which makes sense considering the low passes pretty much right over head. Need that dang low a bit farther SE.

[pondo1000]

12z Euro trying to produce an area of snow with the second low. GGEM was bullish resembling its 12z run from yesterday.

Where was it bringing the snow with the 2nd low?

[Hoosier]

Where was it bringing the snow with the 2nd low?

Roughly eastern KY through eastern Ohio and up toward Toronto.

[snowstormcanuck]

12z Euro trying to produce an area of snow with the second low. GGEM was bullish resembling its 12z run from yesterday.

Anything interesting for me with the secondary?

[Thundersnow12]

12z Ukmet..

[kab2791]

Anything interesting for me with the secondary?

YYZ

WED 18Z 09-MAR   4.9     0.9    1024      53      67    0.00     563     544    
THU 00Z 10-MAR   2.2    -0.9    1019      91      97    0.07     562     546    
THU 06Z 10-MAR   3.1     2.3    1014      92      95    0.20     560     548    
THU 12Z 10-MAR   4.1     3.6    1012      94      88    0.19     558     548    
THU 18Z 10-MAR   5.6     2.6    1010      97      88    0.47     556     548    
FRI 00Z 11-MAR   4.5     2.3    1008      99      82    0.39     555     548    
FRI 06Z 11-MAR   1.7     0.7    1008      97      86    0.26     552     546    
FRI 12Z 11-MAR   0.5    -0.3    1008      95      89    0.16     550     543    
FRI 18Z 11-MAR   1.4    -2.1    1009      93      97    0.09     545     538    
SAT 00Z 12-MAR   0.6    -3.3    1011      92      95    0.19     544     535    
SAT 06Z 12-MAR  -0.4    -3.7    1012      87      86    0.09     544     534    
SAT 12Z 12-MAR  -3.9    -2.6    1013      89      38    0.01     546     535   

[Stevo6899]

50 degrees a day before 10-12 inches in hastings ne. That's March for ya.

[snowstormcanuck]

YYZ

WED 18Z 09-MAR   4.9     0.9    1024      53      67    0.00     563     544    
THU 00Z 10-MAR   2.2    -0.9    1019      91      97    0.07     562     546    
THU 06Z 10-MAR   3.1     2.3    1014      92      95    0.20     560     548    
THU 12Z 10-MAR   4.1     3.6    1012      94      88    0.19     558     548    
THU 18Z 10-MAR   5.6     2.6    1010      97      88    0.47     556     548    
FRI 00Z 11-MAR   4.5     2.3    1008      99      82    0.39     555     548    
FRI 06Z 11-MAR   1.7     0.7    1008      97      86    0.26     552     546    
FRI 12Z 11-MAR   0.5    -0.3    1008      95      89    0.16     550     543    
FRI 18Z 11-MAR   1.4    -2.1    1009      93      97    0.09     545     538    
SAT 00Z 12-MAR   0.6    -3.3    1011      92      95    0.19     544     535    
SAT 06Z 12-MAR  -0.4    -3.7    1012      87      86    0.09     544     534    
SAT 12Z 12-MAR  -3.9    -2.6    1013      89      38    0.01     546     535   

As always, thanks kab. Looks like some backend slush, although what happens with that 2nd storm is very low confidence.

[prinsburg_wx]

15z sref holding it's previous 09z track...gonna be close for my area.

[daddylonglegs]

THE STRONG LOW LEVEL WARMING SHOULD RESULT IN STEADY OR SLOWLY

RISING TEMPERATURES LATE TUES NIGHT FOR THE SOUTHERN 1/4 OF THE

FORECAST AREA. BUFKIT SOUNDINGS AND NORTHWEST-SOUTHEAST RUNNING

X-SECTIONS SHOW THIS LOW LEVEL WARMING...STRETCHING A 1-2 DEGREE

MELTING LAYER UP TO LSE. THIS WOULD SUGGEST SLEET AS A PTYPE.

COMPLETE MELTING LOOKS LIKE IT WOULD OCCUR WITH SFC TEMPS ABOVE

FREEZING...SO DON/T THINK FREEZING RAIN WILL BE A BIG CONCERN AT

THIS TIME. OF COURSE...THIS COULD CHANGE. THIS WARM LAYER IS BETWEEN

06-12Z WED...COOLING AFTER THAT AS INCREASED PCPN/INTENSITY FALLS

THROUGH IT...COOLING IT. THEN...THINK ITS JUST A MATTER OF SNOW OR

RAIN //OR POSSIBLE MIX//. PORTIONS OF NORTHEAST IA/SOUTHWEST WI

COULD STAY PREDOMINATELY RAIN VIA THE 06.12 GFS AND NAM SOLUTIONS.

THE HEAVY SNOW BAND SHOULD BE JUST NORTH OF THE RAIN/SNOW LINE...AND

WITH THE POTENTIAL FOR THIS TO WAVER AS THE MODELS TRY TO LOCK IN ON

THE STORM TRACK...ITS DIFFICULT TO REFINE THE HEAVY SNOW BAND.

HOWEVER...THE MODELS...INCLUDING THE SREF AND EC...ARE PRETTY

SUGGESTIVE THAT IS WILL LIE FROM CENTRAL/NORTHERN IA...ACROSS THE

FORECAST AREA INTO CENTRAL/SOUTHERN WI. THE DENDRITIC GROWTH ZONE IS

RELATIVELY SHALLOW AND WELL A LOFT...WHICH WILL HELP KEEP SNOW

RATIOS LOW...SOMEWHERE IN THE 8/12 TO 1 RANGE LOOKS REASONABLE AT

THE MOMENT. ALSO...IT COULD BE A FAIRLY WET SNOW...CONSIDERING THE

AMOUNT OF WARM/MOIST AIR FEEDING THE PCPN. COBB OUTPUT AND PLAN VIEW

DEPICTIONS OF SNOW AMOUNTS SUGGEST 6 TO 10 INCHES. BARRING ANY

SIGNIFICANT ADJUSTMENTS TO THE STORM TRACK...A WINTER STORM WATCH

WILL BE NEEDED FOR A PORTION OF THE AREA FOR TUES NIGHT/WED. PER

COORDINATION WITH SURROUNDING OFFICES...WILL HOLD OFF ON WATCH

ISSUANCE RIGHT NOW...HANDING OFF TO THE OVERNIGHT CREW TO EVALUATE

00Z MODEL RUNS AND ISSUE THE WATCH.

[daddylonglegs]

I'm sticking with my 3-6 inches of cement.

[Moneyman]

INCLUDING THE SREF AND EC...ARE PRETTY

SUGGESTIVE THAT IS WILL LIE FROM CENTRAL/NORTHERN IA...ACROSS THE

FORECAST AREA INTO CENTRAL/SOUTHERN WI.

What? I'm pretty sure southern WI is all rain on the SREF and EURO. Otherwise, it's a pretty good AFD.

[daddylonglegs]

Oh yeah... i wouldn't be surprised if i get a mix here and maybe even some wet drops on my face.

[snowstormcanuck]

18z NAM still indicating heavy wet snow here, although temps at the sfc are marginal. Tend to think given the flow out of the SE that it's too cool with temps, which would favor more rain.

[mnchaser]

Oh yeah... i wouldn't be surprised if i get a mix here and maybe even some wet drops on my face.

I just got a little turned on, you would like that wouldn't you??

[Moneyman]

18z GFS is a bit south of 12z gfs and a tad cooler. Takes the low to Racine, while 12z was north of MKE. Probably just the 18z gfs being the 18z gfs though.

[baroclinic_instability]

I just got a little turned on, you would like that wouldn't you??

Uhhhhh yeah....

So the 18Z GFS is more or less identical. A tick S--but within the realm of chaos.

[Stevo6899]

It's what's happening aloft that dictates whether the trough goes neg. tilt. This trough does so so early that the sfc low doesn't have enough time to deepen before it occludes. If b_i is around maybe he could give you a more detailed explanation.

I think I see him now.

[baroclinic_instability]

I think I see him now.

I am really tired haha. The answer is actually much longer and more in-depth than one may think--but height field dynamics can get complicated--and as one may expect--the tilt of the height field alone is only a very small piece of the puzzle. Canuck is generally right in that upper level "dynamics" are quite important--but one must also remember height fields themselves are just a small part of the whole "system". In other words, low level baroclinicity also plays a part in how strong the upper level wind fields are (see "thermal wind" http://en.wikipedia.org/wiki/Thermal_wind). In other words--you will never see a 200 kt jet streak over Florida in the middle of summer for a reason (thermal gradients). How a baroclinic disturbance develops with time (does it grow? Does it de-amplify?) is dependent on a number of environmental factors. Always remember that the atmosphere is always trying to establish "equilibrium", and baroclinic waves (mid-latitude storms) are only trying to effectively stabilize an unstable fluid. Perhaps I can give a much better answer when I am not so tired and studying for an upcoming weather exam--but I know others here can answer in a more in-depth manner. I nominate Csnavywx to give a better/more in-depth reasoning. Regardless--negative tilt vs. positive tilt in the height field matters a lot. Storms behave much differently depending on the configuration--but how a storm comes to that overall configuration is dependent upon many factors.

[Stevo6899]

I am really tired haha. The answer is actually much longer and more in-depth than one may think--but height field dynamics can get complicated--and as one may expect--the tilt of the height field alone is only a very small piece of the puzzle. Canuck is generally right in that upper level "dynamics" are quite important--but one must also remember height fields themselves are just a small part of the whole "system". In other words, low level baroclinicity also plays a part in how strong the upper level wind fields are (see "thermal wind" http://en.wikipedia.org/wiki/Thermal_wind). In other words--you will never see a 200 kt jet streak over Florida in the middle of summer for a reason (thermal gradients). How a baroclinic disturbance develops with time (does it grow? Does it de-amplify?) is dependent on a number of environmental factors. Always remember that the atmosphere is always trying to establish "equilibrium", and baroclinic waves (mid-latitude storms) are only trying to effectively stabilize an unstable fluid. Perhaps I can give a much better answer when I am not so tired and studying for an upcoming weather exam--but I know others here can answer in a more in-depth manner. I nominate Csnavywx to give a better/more in-depth reasoning. Regardless--negative tilt vs. positive tilt in the height field matters a lot. Storms behave much differently depending on the configuration--but how a storm comes to that overall configuration is dependent upon many factors.

As always appreciate the input. Hope your enjoying the new job. We could do without the exams.

[wisconsinwx]

The 18z GFS gives me 1-2 inches after putting me in a snowhole at 12z, while the NAM gives 2-3 inches, with Washington County just to the northwest getting up to 6 inches. This will be close, but still need a major shift to get an appreciable storm.

[ksstormhunter]

Still tracking the snow across the Kansas to Nebraska areas. Seeing a shift into more of North Central KS to S. Nebraska for the heaviest snow. With Omaha and Lincoln not receiving as much as thought with a slight northward track of the low. Will have to keep a good eye on this to see the track.

[Moneyman]

21z SREF came in a bit farther SE then the 15z.

21z SREF HR 69:

15z HR 75:

[Thundersnow12]

0z NAM coming in weaker, further southeast, and a hair colder at 850mb here through 54hr.

[Moneyman]

Quite a bit colder. At hr 63, it has a 1004 low north of STL. 0c line for surface is right over me and dropping down a bit from hr 60. 18z had the 0c surface line up near GB at the same time frame.

[prinsburg_wx]

Quite a bit colder. At hr 63, it has a 1004 low north of STL. 0c line for surface is right over me and dropping down a bit from hr 60. 18z had the 0c surface line up near GB at the same time frame.

looks like the ukie

[Moneyman]

LOW ends up tracking towards the S. tip of LM.

[Hoosier]

LOW ends up tracking towards the S. tip of LM.

Map I'm looking at has 1004 mb where IL/WI/Lake Michigan meet at 72 hours.

[wisconsinwx]

I certainly don't mind a weaker low if it means we get a higher % of our precip as snow (the more important part is that it trends colder as well). SE trend is my friend for the first time in awhile.

[Moneyman]

Yeah, at hr 69 it had a 1004 low just west of chicago. I guess it ended up tracking more NEish to the WI/IL border area.

Hour 66:

Hour 72: