Wind Chills Looking Just As Bad As a Few Weeks Ago (Dropping to Near -20 Tonight)……..New Snowfall Information For Late Friday Night-Saturday Morning & Summary of Last Two Winter Systems

January 31st, 2013 at 10:29 pm by under Chad's WLFI Weather Blog

UPDATE AS OF 12:45 A.M.

It is 6.4 degrees at WLFI & just took a wind gust of 31 mph, dropping wind chill to -17.  Autumn’s weather station as Pine Village reads 5.4 degrees with a recent gust to 27 mph.  Her wind chill also dropped to -17.  Mary Anne’s weather station in Remington reads 5.2 degrees with wind gust of 22 mph, dropping her wind chill down to -16.  At Grissom Air Reserve Base, with 9 degrees, wind just gusted to 33 mph, dropping wind chill to -14. 

Be careful out there!

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With temperatures already falling into the single digits with winds gusting to 32 mph, Wind Chill Advisory criteria will likely be met tonight.  Levels will likely reach those of the brutal numbers several weeks ago.  With lows of -1 to 4 & breezy conditions with gusts to 25 mph tomorrow morning, dangerous winds chill of -20 are likely.

Treat it as a Wind Chill Advisory & be careful out there!  You’ll get frostbite in 30 minutes with the kind of wind chills we will have late tonight-early tomorrow morning.

Fast-moving clipper will bring about 5 hours of decent snow late Friday night-Saturday morning.

Looking at latest data, looks like a 1-3″ snow late Friday night-Saturday morning.  Changed it from 1-2″ to 1-3″ due to another high-ratio event of 20:1.

I DO think there will be a NARROW 3-5″ band……………BUT NOT HERE………..thinking that will set up south & southeast of the viewing area.

SUMMARY OF SUNDAY ICE & CONCLUDING THOUGHTS………….

In last ice event, too much dry air was recycled in after days of Arctic high over Ontario bled in very dry air.  By the time the first freezing rain showers/sleet/snow arrived, a chunk of that dry, dry air remained over the Ohio Valley & was pushed in via southeast breezes.  The deeper moisture did arrive by evening with steady rain.  As the rain dropped through 35-degree air with 21-degree dew point, it did drop to 31 over the area for a bit with freezing rain.  However, it then quickly rebounded.  Glaze ice amounts ended up generally under 0.10″ & any morning snow/sleet amounts were minimal.

Arctic highs are snow/rain eaters.  This happens frequently here.  Even if the surface high as moved well to the east, unless there is a good south wind, southeast wind will tend to recycle that air back into our region.  This eats up parts of next precipitation event.  Also, slightly downsloping off Appalachians may play slight role in drying out an already dry airmass to our southeast.

SUMMARY OF LAST SNOWFALL EVENT & CONCLUDING THOUGHTS…………

Last snow event looked like a pretty decent one several days out from an analog standpoint & model data standpoint.  Statistically-speaking the probability of it being a 3-6″ was very high in a look at 5 similar cases over the past 20 years.  One, with no measurable snow in the month probablity was high of a decent snow based on the fact that only 5 Januarys since 1887 in West Lafayette have had a trace or less with only a few others at under 1″.  Secondly, the forcing & dynamics properties were similar to a storm in late January 2004 that dropped a surprise 3-7″ snow on the area after only 1-3″ was forecasted.  The snow ratios were so high with it that 6.7″ of snow fell at Indiana State with only 0.30″ of melted precipitation.

Model data began to diverge tremendously into a performance nothing short of horrendous.  NAM & Futurecast continued to show nothing, most foreign models had a decent snow.

Ended up being a hybrid of the models with most areas seeing around 1″.  Some locations in the far north & far east saw 2-4″.  The least amount of snow occurred in our southern counties with 0.6″ at Crawfordsville & Covington with a pocket around Remington & Wolcott with a trace to 0.5″.

WHAT I DID RIGHT:

1.  Frontagenic forcing was excellent for great snowfall production.  We were able to have an 18:1 to 20:1 snow ratio.  So snowflake production was very efficient.

2.  Storm merger did happen & was in the correct spot in the Lower Ohio Valley.

3.  Snowfall did blossom out seemingly no where with the upper forcing, frontagenic forcing/banding & development of Lower Ohio Valley surface low.

4.  Low-level jet did development & widespread precipitation with convection elements formed on its nose.

5.  Used usual statistical analysis & did case-by-case analysis of each system matching this one in several ways with all dynamical aspects of the system considered.  I then drew a forecasting conclusion from that.

6.  Explained how much uncertainty there was in the forecast & that it would probably be an awful forecast no matter what given extreme dicotamy between data.

7.  Used a strong analog approach, which has aided tremendously in all of my snowfall forecasts.

8.  Feel good that I did painstaking work on this one & tried to let everyone know how uncertain it was.  This was the hardest system I have every dealt with.

9.  Dropped totals to 1-2″ for most of the area by 10:30 p.m. the night before it started with 3-5″ in the far north & far east, which was the most accurate forecast I had for the event.  Explained we would have to rely on now-casting & that the forecast may be a last minute decision, so stay tuned.  Feel good about how I did handle that, despite the forecast’s diffculties.

10.  Learned that analog is usually a way too go as I did learn once again that there are issues to be worked out with U.S. numerical models.  I am glad NOAA is getting the massive brand-new, state-of-the-art supercomputer installations for models in August 2013.  I also know that METS RELY TOO MUCH ON MODELS, but in this case, maybe I did not totally rely on them enough.

11.  I threw out the models that had nothing for us.

WHAT I DID WRONG………..

1.  Low-level jet veered too far to the east & this threw my off.  All the moisture & heavier precipitation blossomed in Tennessee & western Kentucky, rather than southern Illinois & Missouri, like I thought it would.

2.  What I did not see was low-level jet veering so far east.  WHY did it veer so far east?  It appears the major winter drought in the Plains played a major factor.  Major droughts deflect the low-level jet by putting the temperature & moisture gradient or dryline east.  This tend to shift & push LLJ eastward, which is largely responsible for the nocturnal development of widespread precipitation.  The baroclinic zone was too far east.

3.  Afformentioned low-level jet shift cut our moisture DRASTICALLY.  Our snow was 100% DRIVEN by upper dynamics & frontagenic forcing in 850-700 mb layer.  With such impressive forcing, it took hardly ANY MOISTURE AT ALL, really, to make the snow.  Foreign models painted up to 0.25″ liquid for area with 18:1 to 20:1 ratio.  Only 0.06″ of liquid occurred at WLFI with the 1.0″ of snowfall.  At Kokomo, the 2.5″ snowfall melted to 0.11″.

4.  Snowfall duration was much shorter than I thought.  It was pretty much a 3-hour event.  I figured it would be a 6 to 7 hour event.

5.  My data was so consistent & agreed so much, I had a 4-6″ graphic several days out, followed by a 3-6″ graphic.  I put a 4-6″ & 3-6″ graphic too early.  For snow like that, I should’ve waited a day, even if my numbers were on my side.  I did not like having to trim numbers over & over.  That goes against what I believe as a met.

6.  I need to watch that LLJ in these situations & where the LLJ zone exists based on a tendency for it to shift east at times with that major Plains drought.

Overall,  this boiled down to WATER, WATER, WATER………………or a lack thereof & the direction of transport of that water.

23 Responses to “Wind Chills Looking Just As Bad As a Few Weeks Ago (Dropping to Near -20 Tonight)……..New Snowfall Information For Late Friday Night-Saturday Morning & Summary of Last Two Winter Systems”

  1. mad man from afghanistan says:

    Fox said 3 to 5 , but who knows, i hope we get at least 4 or 5 that would be nice

  2. Plower says:

    Indy said 3-5 for a wide 3 counties wide north to south. I will believe things will they start adding up on the ground

  3. ch n ffort says:

    Yea mad man just got my entertainment for the evening watching the ” big ” guys say anywhere from 1-5…lol…waiting for chad to give us the real deal

  4. James says:

    I don’t know why you guys watch Indy. Said 1-5″. That doesn’t help much. I am sticking with chads 1-3″. He seems to have more common sense and more ability than those guys at indy. Those big ol indy guys think they got it down pat but are rarely rite.

  5. Plower says:

    Bc I’m in Westfield and just watching news. I’m not always at my house in mulberry so I watch what I can see. And compare both. Plow lafayette and Frankfort. Ill say 2-3

  6. ch n ffort says:

    Calm down there james..lol..as i said i watch indy for entertainment purposes..i always go with chad no matter what

  7. Joey says:

    Does anyone know what criteria schools use for delays w/the windchills? Seems like some schools always delay in situations like this(there is a big list already), but others (like Lafayette, W.Laf. and Benton) never seem to. Is there a standard they all supposed to go by, or just up to each school corp.? Just curious, thanks.

  8. Jim says:

    Chad thank you for sharing your thoughts. And taking your time and effort to explain The last events. MadMan Monster enjoy the snow. I am with Chad on this one 3,looks good.

  9. ch n ffort says:

    Chad..2 questions for you. I know there is a wind chill chart but what kind of mathematics or formula is used to get the numbers. And do you see much wind with snow this weekend? Trying to figure out how long my weekend at work is going to get..lol..thx man

  10. Jim says:

    Schools and Wind Chill. I believe the air temp needs to be below 5. With wind added in. That being said.it would be smart to do your delay notification the night before. Chad your explanation of the last two systems was great. I had said I was wondering about the dry air. However you mentioned the things wrong with your forecast? Man you followed your instinct. That’s what we admire about your style. Thanks great job you did nothing wrong.

  11. James says:

    Wow, a weatherman who will write about what he did wrong on a forecast…that makes me trust him all the more. Thanks for all the hard work Chad. I watch your forecasts and read your blog for my weather info.

  12. Mary Anne Best says:

    Once again, Chad thanks for the explanations. I for one, and it seems to be unanimous, NONE of us here need an explanation of what you did “wrong” :-) I hope you read all the comments on this blog post. Listen to what “they” speak of the Indy guys…entertainment..coming here for the real deal!

    Weather forecasting is just that…forecasting. Mother Nature does what she wants to. YOU are the best MET in the state!! (as far as we are concerned, LOL)

    We count on you and you deliver!

    MA in REM your number one fan :-) Temp this morning is 2* with a 10 mph wind and a school delay.

  13. Jim says:

    Fox 59 who?

  14. Spider says:

    We should be very thankful to have such a great meteorologist in our area. It’s very evident that Chad works very hard and he even takes time to explain absolutely everything. It stinks that we aren’t getting the snow that many of us want, but Mother Nature is in control! And, apparently, she’s playing lots of tricks to keep the snow away from us!

  15. Ryan H says:

    Ditto Mary Ann…….

  16. Duane C says:

    Personally, I don’t think it hurts to watch all of the Indy stations as well as wlfi. They all have the same types of models to view. Some of them put more stock into certain models and data. No meteorologist needs to apologize..nor should they be put up on a pedastal all of the time. Any person should try to put their best effort into their work. I believe Chad does this, but I also believe some of the Indy guys and gals do too. People take this blog way too seriously sometimes. They act as though any criticism of Chad or Prangley before him is personal. It is often just frustration and disappointment that some of the bloggers are feeling. Some of our fellow bloggers rely forecasting in their planning of snow removal. When forcasted snows don’t come to fruition they don’t make any money. Some people just genuinely love snow. They also become disappointed when forecasted snow doesn’t come to light. I doubt that any of them are seriously upset with Chad. They are disappointed in the data and Mother nature. It was do us all some good to loosen up. Chad probably gets a kick out of all of this. I know one thing, he should feel liked. You all circle the wagons for him enough.

  17. Maybelater says:

    Forecasts are bouncing all over from 2 to 4 inches and 1 to 5 inches but I think Chad’s forecast is right on the money.

  18. mad man from afghanistan says:

    Im surprized there are no watches or warnings yet.

  19. Jim says:

    Madman. Gfs model saying 3-4. Advisory may be issued I’m not sure when Nws will. You know maywhatever yesterday said he didn’t know where I came up with my 2-4 prediction well I’m sure he can change his words now. I agree somewhat with Duane’s comments because you monster and myself where blasted last week for speaking our minds. Dint get it I’m glad to have the opportunity to talk to you Guys on weather topics. Chad dies the best he can but man he admitted being wrong in some things and why last week. That takes a big person to do that my respect for him grows. I haven’t his lasted update on this snow. We will see. Read 2 in Kentland this am wind at 17 mph cold. Talk at you later. Moe

  20. mad man from afghanistan says:

    Jim whats the water ratio for this clipper, i hear its rather high , does that make a difference? Please let me know, im kinda confused with that scenario, thanks bro, hey did you get my email address on here?

  21. Duane C says:

    Agree with you Jim. Im just saying he doesn’t even have to apologize and people dont need to defend him. He predicts using the best information available. Noone can be right all of the time. All of us should feel comfortable enough to speak our minds…within reason. It is never personal with me. I just call it the way I see it. Sometimes I am not the most politically correct person. It is absolutely not personal. I think all weathermen need to develop pretty thick skin>.LOL

    I like a 2-3 inch call myself with this one.

  22. mad man from afghanistan says:

    4 to 6 is my call, perhaps a little more.

  23. Jim says:

    Duane totally agree. It’s like if you say something bad your in the principals office with people. I call it as I see it. I like 2-3 on this one. Chad is right there with us. Also. MadMan. Keys go 2-3 man maybe pushing the 4. We will see. Moe

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