Chris's Corner - Valentine's Day Winter Storm
Feb 14, 2021 5:46:26 GMT -6
REB, Labrat-O'Fallon IL, and 3 more like this
Post by Chris Higgins on Feb 14, 2021 5:46:26 GMT -6
Happy Valentines Day and welcome to a real winter storm!
First… the dangerous cold. Temps and wind chills are now below zero across almost the entire region. This is extreme stuff by any standards. Please remember those who cannot pay their utility bills and donate to @heatupstlouis.org. Also, don’t forget your pets! This cold is tough for their little paws too!
Now to the snow. It is EXTREMELY RARE for us to get a significant snow with temperatures this cold! In my lifetime I don’t remember any…although I’m sure there have been. So let’s get to it…
A substantial winter storm will impact the region in several waves. The first wave will bring snow to much of central and parts of eastern Missouri by mid/late morning. It is questionable just how much of this first wave will impact the metro STL area. However, a steady light snow is likely west of St. Louis… with at least a few bursts of light snow and flurries in the metro before noon. This will surely get everyone excited…and then worried when the forcing for the first wave diminishes for a time this afternoon and things settle down for a few hours. Be patient!!!
The main snow event unfolds after 4pm this afternoon and will last well into Monday. Periods of snow will fall (yes…all snow) as a respectable upper level wave moves across the region. There continues to be some uncertainty as to how long into Monday the snow will last…especially with respect to a third wave that has been shown in some models at times. Most recently, the hot off the press 06z NAM, 00z GFSv16 and the Euro agree that wraparound/deformation snow will linger well into Monday afternoon…especially over eastern Missouri into southern Illinois. Fortunately, this was mostly accounted for in my previous forecast.
A big question is the ticklish LSR question… which could turn a moderate snow event into a heavy one. It seems obvious that 1:10 standard will not cut it here… but not sure we’ll pop to 40:1 of yesterday lol. That was extreme. COBB output is about 13:1 which seems a little low too. I’m going to go with 15:1… applied to a slightly decreased QPF total (I’m assuming the models are too wet with liquid equivalent…because they almost always are). This ends up pushing most of the area to about 5 or 6 inches. A solid winter event!
To account for variances in subtle features that are difficult to track… I still think a widespread 3 to 6 storm is on track for the entire area…with most areas leaning closer to the high end of that range…or 5 to 6. Could there be more? Absolutely… if the LSRs are too conservative or QPF goes up even a smidge… then the totals could be higher. No matter how you slice it… still a substantial winter event!
First… the dangerous cold. Temps and wind chills are now below zero across almost the entire region. This is extreme stuff by any standards. Please remember those who cannot pay their utility bills and donate to @heatupstlouis.org. Also, don’t forget your pets! This cold is tough for their little paws too!
Now to the snow. It is EXTREMELY RARE for us to get a significant snow with temperatures this cold! In my lifetime I don’t remember any…although I’m sure there have been. So let’s get to it…
A substantial winter storm will impact the region in several waves. The first wave will bring snow to much of central and parts of eastern Missouri by mid/late morning. It is questionable just how much of this first wave will impact the metro STL area. However, a steady light snow is likely west of St. Louis… with at least a few bursts of light snow and flurries in the metro before noon. This will surely get everyone excited…and then worried when the forcing for the first wave diminishes for a time this afternoon and things settle down for a few hours. Be patient!!!
The main snow event unfolds after 4pm this afternoon and will last well into Monday. Periods of snow will fall (yes…all snow) as a respectable upper level wave moves across the region. There continues to be some uncertainty as to how long into Monday the snow will last…especially with respect to a third wave that has been shown in some models at times. Most recently, the hot off the press 06z NAM, 00z GFSv16 and the Euro agree that wraparound/deformation snow will linger well into Monday afternoon…especially over eastern Missouri into southern Illinois. Fortunately, this was mostly accounted for in my previous forecast.
A big question is the ticklish LSR question… which could turn a moderate snow event into a heavy one. It seems obvious that 1:10 standard will not cut it here… but not sure we’ll pop to 40:1 of yesterday lol. That was extreme. COBB output is about 13:1 which seems a little low too. I’m going to go with 15:1… applied to a slightly decreased QPF total (I’m assuming the models are too wet with liquid equivalent…because they almost always are). This ends up pushing most of the area to about 5 or 6 inches. A solid winter event!
To account for variances in subtle features that are difficult to track… I still think a widespread 3 to 6 storm is on track for the entire area…with most areas leaning closer to the high end of that range…or 5 to 6. Could there be more? Absolutely… if the LSRs are too conservative or QPF goes up even a smidge… then the totals could be higher. No matter how you slice it… still a substantial winter event!
