Winter Storm Brewing - But for Who - Now THAT is the question?

Latest plausible indications continue to push a strong cold front through Southeast Lower Michigan slowly overnight Thursday into Friday morning. Rain with become mixed with/and changes to sleet and then over to snow as the atmosphere column thickens with the colder, snow supporting air. At this time; the front will slide east and southeast as a developing low pressure and storm rides north northeast along the front pushing heavy snow and mixed precipitation through the Ohio Valley and on into the Northeast. In the colder air behind the front over Southeast Lower Michigan; up to a couple of inches are possible on Friday.

Beside the upper air support for the low pressure and storm, it must be noted the High pressure pushing southeast into the northern plains will exude a strong push of Arctic air, once again, southeast into the country. This too will aid in pushing the storm out to the east-northeast. I drew a dotted line as of this writing the snow still could push along that "buffer-zone" if the storm develops faster, high weaker or upper air isn't sampled well enough but the above scenario seems most likely.

Now here's the caveat: model sampling of the atmosphere from upper air, satellite and radar is still not complete as the energy and subsequent phasing is still ongoing. Yes, things can change but again at this time the above seems the most plausible. If dramatic changes evolve from better model sampling and data, I'll surely update.

Let me just say; again with some models predicting an Armageddon snowstorm for the Ohio Valley and at times extending into the Southern Lakes, I've stayed out of it with nothing written on it. The crap put on various web-sites pumping an almost certainty fictitious amount of snow for some areas was ridiculous! Those posting 2 or even near 3 foot snowfalls across portions of Southern Michigan into the northern Ohio Valley; especially when many records for 100+ years would be shattered is complete disregard to the general public. I'm not talking about various weather forums that are a mix of all interests...these extreme model solutions hopefully stay with those members, who generally know the "problems" with model output.

Every time there is a hint of a "big" storm, several of these snowstorm enthusiast (spelled N.U.T) start posting the most extreme solutions. Several have questionable educational backgrounds - if any in meteorology - and never even worked in the weather field. And, this happens EVERY winter with the advent of the internet. I can't tell you how many times before and after I retired from the NWS, I was asked: "I heard we are getting this "huge amount of snow" is it true, what do you guys say - and it really has blossomed the past 10 years.

Model forecasting has improved phenomenally in the past 20 years, especially the past 10 but they still get it wrong as all forecasters do. Sometimes during a season, one or two models will have the inside track for accurate forecasting that particular winter - and days out - only to lose it off at times.

I've certainly gotten it wrong on individual events and my Outlooks, nobody is infallible but I try to be reasonable and write various articles and blogs the most objective and limit, to use the in-vogue vernacular -  "Fake News".  Many times when something I forecast is wrong or out of bounds with what happen, I do talk about what went wrong and I wish more would do that because I try to...

Make weather fun while we ALL learn,
Bill Deedler - SEMI_WeatherHistorian


  1. Bill, have you ever heard of the Kuchera snow ratio? I can't find any information on this. I thought perhaps you might know.

  2. Oh yes, it is useful in determining forecast snowfalls when the typical 10/1 ratio is not feasible.

    Contact: Evan Kuchera
    0.5 degree isobaric GFS GRIB data from NCEP.
    The snowfall accumulation algorithm used on these charts is as follows:

    1) Find the maximum temperature in the lowest 500 hPa in degrees K (MAXTMP)
    2) If MAXTMP is greater than 271.16K, then the liquid equivalent ratio (RATIO) is 12.0 + 2.0*(271.16-MAXTMP)
    3) If MAXTMP is less than 271.16K, then the liquid equivalent ratio (RATIO) is 12.0 + (271.16-MAXTMP)

    The 3-hourly snowfall (SNOW) is RATIO multiplied by the three hour liquid precipitation total. The accumulated snowfall (ACCUM_SNOW) is the sum of all the SNOW values up to that projection time.