Winter Storm Coverage

hd_winter_storm_information2A complex and possibly historic winter weather situation is upon us within the next 48 hours as two storms combine to potentially drop extreme snow amounts.

 Blizzard Warning valid at Feb 01, 3:00 PM CST for  Jo Daviess, Carroll, Whiteside and Stephenson [IL] till Feb 02, 12:00 PM CST  

4:00 Update:  Tonight we can expect 2-5 inches by Tuesday morning.  The second round of snow arrives Tuesday night into Wednesday where we can expect another 7-13 inches (all forecasted total accumulation is for Rockford Metro).  High amounts can be expected to the  South with lesser amounts to the North.

Blizzard Watch valid at Feb 01, 3:00 PM CST for Green [WI] till Feb 02, 3:00 PM CST

Blizzard Warning valid at Feb 01, 3:00 PM CST for Jefferson, Rock and Walworth till Feb 02, 3:00 PM CST  

Blizzard Warning valid at Feb 01, 3:00 PM CST for Boone, Cook, DeKalb, Lee, McHenry, Ogle and Winnebago till Feb 02, 3:00 PM CST

conus_gfs0p5_sfc_accum-snow_72hr3:30pm Update – Here is a look at the raw output from the GFS model. It gives you an idea of the scope of this winter storm/blizzard. We expect all counties in our coverage area to be under Blizzard Warnings for the Tuesday night through Wednesday evening timeframe. Total snowfall accumulations will be in the 10-20 inch range from north to south across the WREX coverage area for Tuesday night into Wednesday morning. We will have a few inches between now and the time the main, system snow arrives Tuesday night. -ES

3:00pm Update:   Just took a look at the newest model data and everything is still on track.  The storm track runs from Southern Arkansas to Western Tennessee/Kentucky into Southern Indiana and Eastern Ohio by Wednesday morning.  From Tuesday evening into Wednesday morning is the time-frame where we expect the strongest part of the storm.  This is when we can expect snowfall rates between 1-3 inches per hour, winds gusting up to 40-50 mph as well as rumbles of thunder.  This will create blizzard conditions with 4-8 ft snow drifts and visibility less than 1/4 mile.  Traveling will likely become impossible during this time-frame of Tuesday night into Wednesday morning. 

10:30am Update –  41as I continue to pour through model data and check out various forecasting methods (Cobb method and Magic Chart method for you snowheads), it appears as though our viewing area may have a substantial variation in accumulated snowfall if the system does in fact keep its current track. Locations in southwestern Wisconsin will likely see less snow than those that reside nearer to Chicago and points south of I-80.

Check out this forecast sounding from the NAM. If you are not familiar with the DGZ, you soon will be. The DGZ (Dendritic Growth Zone) is the column in our atmosphere, between -20 and -10 degrees, that is most efficient at producing snowflakes. When the air is saturated within this zone (the green moisture line near the red temperature line), snow is formed. The longer these saturated conditions exist as the snowflake falls, generally the bigger and more intense things will be at the ground. A saturated column from nearly 500mb to 925mb is certainly impressive and will yield very efficient snowfall if it verifies.

Today’s storm system, the weaker of the two, will slide off to our north and drop between 1-3″ of snow in the area. 3aLook for slightly heavier amounts close to and just north of the Wisconsin state line. Tonight, there may be a slight lull in the snowfall as we transition to the second, and much stronger, system.
As an area of low pressure continues to deepen in the southern states today, it will ride along a strong temperature transition zone toward central Illinois. As the local area will be along the northern fringe of this low, we will be in prime position to see some of the heaviest snowfall. As it looks this morning, the potential exists for some people in our viewing area to see up to 15 inches of snow from Tuesday/Wednesday’ storm alone. Amounts will be greater to the southeast of Rockford toward the Chicago area where 20+ inch amounts are possible. Travel will become difficult if not impossible Tuesday afternoon through the entire day Wednesday as winds pick up and cause blowing and drifting to several feet above actual accumulated snowfall. 23Temperatures will become a concern with windchill values to -30 at times Wednesday.

One point I cannot stress enough is about the track of the storm. Although it is an almost 100% certainty that we will all see significant snowfall totals, a deviation in the track of the storm could mean the difference between 6″-12″ or a band of 12″-20″ for any given location. As this storm continues to evolve and phase with our weaker northern storm, slight tracking differences are inevitable. On the flip side of this point is the possibility for lighter snow amounts. Strong systems usually have a fairly narrow corridor of the heaviest snow which we will continue to refine as the storm draws nearer.

132This morning, I ran our in-house computer model and changed the path of the storm to the north by 75 miles. Take a look at the absolutely impressive snowfall totals if this does in fact happen! As much as 18-22″ of snow would be on the ground if this scenario were to play out. Travel would be nearly impossible, even with 4 wheel drive. Now is the time to prepare and get any midweek plans completed.


Posted under snow, winter storm

This post was written by qni_it on January 31, 2011

27 Comments so far

  1. jason January 31, 2011 6:54 AM

    wow thats alot of snow ill be staying in thanks -AB U ALL DO THE BEST THANKS TO THE 13 WEATHER TEAM U ROCK!ill be checking in all day for updates

  2. BillNole January 31, 2011 7:06 AM

    Are you saying you changed the input variable by 75 miles AB, or did the output change by 75 miles?

    Interesting exercise, but I’m curious as to whether you were just playing around, or your model is actually forecasting this change?

  3. Jason January 31, 2011 7:14 AM

    Aaron, the graphic you showed had Rockford with 13.79″ at 3:30 am on Wed. am. My question to you, is, is the snow done at that point, or we still in line for more snow during the day on Wednesday? And if so, how much? 13 Weather rocks!

  4. Aaron Brackett January 31, 2011 7:20 AM

    Bill, I included the raw model output which gives the Rockford area about 13″ of snow and then ran it again while pulling every variable north by 75 miles, or essentially changing the track of the low further north.

    Jason, The storm will likely be winding down early Wednesday morning as far as new snow is concerned. This is certainly not the end of the treacherous weather as winds will be gusting to nearly 40 at times causing drifts of several feet!


  5. Polo mom January 31, 2011 8:26 AM

    was just told that it is drifting on 26 from Polo to Forreston

  6. jason January 31, 2011 8:39 AM

    yea the winds have picked up here in forreston!

  7. BUB - Belvidere January 31, 2011 9:08 AM

    COME ON 2 FEET!!!
    I love my snow!

  8. Sarra-NW RFD January 31, 2011 9:17 AM

    I hate to ask this far out, but how will car travel be on Thursday (other than bitterly cold)?

    Thank you!

  9. WI Weather Buff January 31, 2011 9:46 AM

    Any idea “when” on Tuesday the more severe conditions are scheduled to hit?

    Reason I ask: I have to go to my office either Tues or Wed (can work from home the other day) and I picked Tues.

    But for me “going to the office” is a 60 mi commute up I-39/90 from Beloit to Madison, WI.

    So – I’m planning on going up on Tues, knowing that the Blizzard is scheduled to hit Tues eve. But for me the question is going to be — “How soon do I need to Get Outta Dodge (or more to the point, leave Madison) on Tues in order to avoid getting caught in a really nasty blizzard on the way home?”

    I have driven that commute in absolutely frightful blizzards before, and absolutely don’t want to have to do that again.

  10. BillNole January 31, 2011 9:52 AM

    I’m on the phone with a customer in Union, MO. (1 hour SW of St. Louis) They say they started with sleet about an hour ago, but it switched to heavy rain (a relative term…) 1/2 hour ago and the temps are holding at 32 degrees. They called off their plant personnel, but the office is still open. Not sure how long that will last. I’m not going…

  11. Eric Sorensen - WREX January 31, 2011 11:05 AM

    Remember, we’re not electrical engineers and can’t forecast what capacity of snow the grid can take. However during blizzard conditions we usually do have outages. Prepare, just in case.

    In addition, no one should be planning on driving ANY vehicle from 8pm Tuesday through Noon Tuesday (at the earliest) as snow drifts are forecast to be in the 3-8 foot range. Seriously, work around the winter storm now, tomorrow, and catch up Thursday and Friday. -ES

  12. Pam in Poplar Grove January 31, 2011 11:44 AM

    I am hoping to be well enough to go into work early tomorrow (we’re fighting respiratory virus) and leave early tomorrow. Wednesday and Thursdays are my normal days off…lucky me! Didn’t think about power outages…

  13. Terry January 31, 2011 11:53 AM

    I work 2nd shift (3pm – 11:30pm) so I’m guessing I need to say my good-byes to the family and all. I probably won’t make it home Tuesday night.
    So long World. 🙁

  14. Mark January 31, 2011 11:59 AM

    I’ve been reading that storm is tracking furher south and we’re only getting 5-9 inches

  15. Justin January 31, 2011 12:18 PM

    What causes the ‘hole’ in exactrack models near lake Michigan? Does the software simply not have a color for more than 20 inches of snow?

  16. tony January 31, 2011 12:29 PM

    And where did you read that at mark. All forecasts I am seeing is still for up to 15 inches. I will just watch 13. They will know everyting about this storm. They are the best.

  17. Lanell January 31, 2011 12:39 PM

    With this storm comming and possible power outages I suggest FILLING your BATHTUBS with water tuesday morning. Thus you have water to flush toilets, water small animals and wash up with specially rural area people on your own well.

    Is there going to be a period without snow tuesday morning?

  18. Mark January 31, 2011 12:43 PM

    read it on niu weather site. 13 weather are the best though

  19. tony January 31, 2011 12:44 PM

    I will rely on 13 before NIU weather site.

  20. Steven January 31, 2011 2:25 PM

    Can we officially call this Snowmageddon 2011?

  21. Walt January 31, 2011 3:02 PM

    Sorry to burst the bubble mark but I just looked at NIU weather site and they linked to NOA weather which says Significant snow accumulations possible. To them that means over a foot but unable to accuratly predict amounts as of yet. I personally will watch for updates from Eric and Aaron as they have never done us wrong. Eric please update us as mutch as possible on the storm track. I would personally love to see it mover farther north. Have fun sledding with your kids! I know I will.

  22. Justin January 31, 2011 3:26 PM

    I found that on the NIU site as well. Keep in mind thats what they are forecasting for Rockford for ONLY overnight tuesday.

  23. jason January 31, 2011 3:42 PM

    wow thats alot of snow eric just woundering when the last time we got that much snow?

  24. jason January 31, 2011 3:43 PM

    so we can see almost 2feet when it all done eric?im in forreston

  25. Justin January 31, 2011 3:49 PM

    I honestly don’t think the precise forecast really matters one you get past 8 inches… especially with wind like whats expected only a couple inches would cause huge problems.

  26. Lanell January 31, 2011 4:00 PM

    We plow snow and our plow will NOT turn a wheel untill wednesday late morning early afternoon. Not gonna fight this one.

  27. Mark January 31, 2011 4:10 PM

    Any chance this will track further north

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