Joe’s Weather Blog: Another snowstorm likely for the region (MON-2/18)
So storm #1 was a 3-5″ (mostly) snowstorm…it was a light powdery snow than happened quickly and turned the roads into a true mess because of the timing. Then we had the “dippin’ dot” storm that made some areas slick and was curiosity more than a high impact type system…now we have storm #3 coming Tuesday evening/night and that has shades of storm #1 in terms of amounts…although it may not be as “powdery” as storm #1. Oh and we have storm #4 to watch for the weekend that may melt away everything on the ground and then try to add more snow on the tail-end.
I need a scorecard…and you want a break.
Today: Cloudy skies and cold with highs in the mid 20s
Tonight: Variable clouds and cold. You may want to check out the moon at perigee tonight. The true “supermoon” is tomorrow night but you won’t see it because it will be snowing. Tonight the moon isn’t 100% full but it’s close and it’s also at “perigee” which means the distance the moon is from the earth is shorter than average. Lows in the teens
Tuesday: Lowering clouds with some snow possible in the afternoon BUT the main part of the storm will be in the evening and overnight into early Wednesday AM. Highs in the 20s
Wednesday: Snow quickly ends towards daybreak…perhaps as some freezing mist/drizzle (sure why not at this point). The some clearing in the afternoon with highs in the 20s
Before I get into whats coming tomorrow evening and night…a note for those hoping for prolonged warmer air…or perhaps a quick start to Spring…ummmm nope.
Looking at the overall pattern and some of the model maps…we’ll finish FEB cold…and start March cold. Let’s remember that by the end of the month our average high is getting closer to 50° and that won’t happen (at least for any prolonged period of time I don’t think.
At least well below average temperatures in late FEB and early MAR aren’t as brutal as well below average in early JAN. In other words 20° below average in early March is closer to 30° for highs whereas in early JAN that would be closer to 20° for highs.
Let me show you what I’m talking about…this would be from very late FEB to the 4th day of March…this is a 5 day average of temperatures just above the surface at around 5,000 feet or so.
The anomalies are about 7-10° C below average and that’s about 15-20° F below average…no bueno.
The GFS Ensembles aren’t much different at all…
Notice in the map above towards NW Canada and AK…yup…when it’s warmer than average up there…that means usually it’s a colder than average down here
There is also another developing story…and that is the flooding risk…not here (not yet) but towards the southern US…I’m looking at maybe 10″ or more of rain in the TN Valley region.
This will make the weather headlines I think this week…that’s a lot of moisture. Oh and there could be severe weather over the weekend in SE MO
Maybe…maybe(?) later that 1st week of March…we can moderate a bit more…at some point these cold patterns relax…there is only so much cold out there…we need to get rid of the snowcover as a first step though. Speaking of which…54% of the country is under some snow this morning. Last year on this date it was 37% and back in 2017 it was 23%…so big changes…I smell a What Your Weather App Can’t Tell You segment tonight!
I got a facebook post from a nice person who was getting tired of all the snow. She mentioned that she would’ve have been fine with this around Christmas and the New Year…and she was wishing that could’ve happened. Most enjoy the snowy weather around the holidays. Remember how the holidays went this year? It was about 50 days or so ago…at least New Years was…we started the New Year chilly but had about a week of temperatures almost 20° above average during that 1st week of JAN…heck that last week of December was mostly well above average too…we were in quite the stretch of mild weather to finish 2018 and start 2019.
Alas distant memories. We did start this month with warm air…heck we were in the 60s! Not anymore. We’re running almost 3° below average this month…and well trend father down over the next week or so.
Heck last year it was 71° on 2/28…
Then again last year March and April were sort of “strange” too.
The system tomorrow evening looks to bring more accumulating snow to the area. There are still some questions as I’ve illustrated for you over the past few days concerning where the highest snow totals will be…odds favor north and northwest of KC. How quickly any potential dry slot will zip up from the SW and shut down the better accumulating snows…will there be some freezing mist/drizzle at the end of the storm? A lot of these questions will revolve how a wave is kicked out of the main anchor storm in the SW part of country.
This dry slot potential will bother me till tomorrow afternoon I think.
It’s important because it will determine whether we have 9-12 hours of snow or IF we get 4-8 hours of snow…and that difference could mean another 1-2″ of accumulations.
Our confidence is highest across northern MO where the dry slot is delayed the longest and the snow may be heavier for longer…4-8″ of snow seems likely in northern MO north of 36 highway. A Winter Storm Watch is in effect for that part of the region.
Those are the counties lit up in blue and when a warning is issued…those counties will switch to a pink color. The map above will auto-update for you.
For the KC area…odds are another Winter Weather Advisory is coming. The counties involved will be lit up in a purple color. Expect that to happen later today.
So this is what still bothers me about this whole set-up…and again it’s my job to look for what can go wrong in certain set-ups and not just buy the models hook, line and sinker. I’m always looking for what ifs.
I’ve explained my “what if” issues already. The thing is IF one were to look at the upper air forecasts one would conclude that we might get some quick hitting accumulating snow and then quickly dry slot. Why? Usually, it seems like all the other winters lately , when a vigorous wave passes to the NW of the region we get dry-slotted faster rather than slower. The dry slot refers to drier air (less saturated) moving up from the south or southwest or even west.
The storm now is in the SW part of the country.
There is another piece up towards MT too. That will drop towards the south and merge with the storm by Wednesday early AM and this should happen in CO later Tuesday night. That merged system will then lift through the western Plains region it the upper Midwest. On the face of it…with that sort of track…we should see a rapid dry slot come up from the SW part of the country.
The key to use getting 4″ of snow will be a wave connected to this main storm pulling into the western Plains…and how long we get involved with that as the dry slot connected to that wave comes up from the south. As long as we don’t get dry slotted till after 12AM WED…we should get at least 2-4″ of fast accumulating snow tomorrow night.
Then after the dry slot moves through (and it will I think) right after 12AM…the snow rates will drop of significantly. This is when we’ll see lighter accumulations because without the moisture up at close to 10,000 feet…snowflakes don’t form as efficiently and you get MUCH lighter snow to fall…or even freezing mist/drizzle/sleet to fall.
Let me illustrate what I’m talking about…let’s go up to about 10,000 feet and show you the humidity levels…or the amount of saturation up there in the clouds where snowflakes love to form.
These maps are via Pivotal Weather. The map below is for 9PM…off the latest NAM model.
It should be snowing pretty good at the time above (9PM). It better be because look at the following map…3AM Wednesday.
So the bottom line is we need to make hay between the onset of the good sticking snow…probably after rush hour Tuesday…through about 1-2AM Wednesday morning…because after that I’m not sure how we get more than 1″ of additional accumulations.
Now we can indeed still get 2-5″ in that scenario. I think 2″ is easy…3″ should be pretty easy. 4″ should be very doable…after that it gets much tougher I think.
I started with a 2-5″ forecast and I still think that is the best forecast at this point…maybe 3-5″. I noticed KR and MB upped that to 3-6″ which is more or less fine to me. IF there was a 6″ total it would be more towards the far northern part of the Metro…perhaps towards or north of KCI.
I think the hi-res NAM has a good idea of how this plays out for snow totals…at least for western MO and eastern KS.
For KC that’s a solid 3-4″…lighter towards the SE of the Metro…towards the Lakes region and higher into NW MO…perhaps 6-7″ up there.
Again this may be very similar to the storm #1…except the snow won’t have that “fluff factor” of storm #1 for most of the area.
If we could manage to squeak out another inch of snow after the dry slot comes through…we may add 1″ to the KC numbers above.
So since many of you told me you liked this approach…this would be for KC.
Up to 2″: 100%
Alright this blog is long enough for today. Our feature photo comes from Joan Buie Thornbrugh