Joe’s Weather Blog: Snow expected…should get very messy (THU-1/10)
Our 2nd snowstorm (not as dramatic) as the blizzard is still expected to hit the region later Friday into Saturday morning. Snow, moderate to heavy at times, will fall and accumulate. Roads may initially put up somewhat of a fight…but will eventually turn slick and snow covered. There remain questions (we’re talking 1-3°) in the temperatures, and the heaviest areas of snow, but this will be a pretty big ticket item on Saturday morning at least.
Today: Variable clouds and seasonable with highs in the 40° range
Tonight: Increasing and lowering clouds and not as cold with temperatures near 32°
Friday: Cloudy with rain showers developing. There might be a few patches in the AM but the better chances are in the afternoon. Highs in the mid 30s
Friday night: Rain changes over to snow. Moderate to heavy wet snowfall is possible. Accumulations begin. Temperatures drop to near 32°
Saturday: Snow slowly tapers off to snow showers/flurries later in the afternoon. Accumulations end. Totals expected to be in the 2-4″ range for most of the area. There remains some upside to that the farther east/north you go from the KC region. Temperatures in the 32-35° range all day. The snow may continue through the game…
Sunday: Gray and cold with stagnant temperatures and highs near 30° with snowcover keeping things cold.
Things continue to fall into place and in an effort to simplify my forecast thoughts…I’m most concerned about what happens between roughly 6PM Friday night and 6AM Saturday. On the assumption that anything before that is rain, or even a wintry mix and snow, my thoughts are that there should be melting happening before 6PM Friday. IF there is appreciable sticking snow…then there will be upside to my forecast of 2-4″ for the KC area. My thoughts are the with temperatures a couple of degrees above 32° before 6PM Friday…that accumulations will be somewhat tough to come by.
So with that said…let’s talk about the storm coming this way. There are still the usual questions..somewhat a bit more complicated by how the temperatures in the lower 2,000 feet of the atmosphere will respond to a persistent south wind and efforts to stay near 32° just barely above the surface. This really isn’t an issue with a storm track or anything at this point (at least to me) since we’re talking about broad scale lift to the atmosphere over a wide range of territory. There will be heavier bands setting up (as usual) and those bands will determine potentially some 3-6+” totals. Where they set up will be a nowcast situation early Saturday I think.
The system itself will be moving through the western US today…it’s onshore and has been for the last 12 hours or so. You may need to look carefully at the water vapor loop showing the little twist in the western US in the CA region…tough to make out.
This is a break-off of the big Pacific storm that has now fallen apart and broken into many pieces that I showed you from the other day.
This will come out and over the Rockies tomorrow. Strange things can happen with these disturbances as they cross over the mountains and come into the Plains but based on the data this morning this should turn into a decent upper level storm as it comes along the I-70 corridor. The upper level feature is actually taking a nice track. Any farther north and we’d get concerned with some weird dry slot cutting off the snow production (or reduce it to little accumulating snow production). So that is a decent track.
Here is a look at the disturbance coming across the Plains tomorrow and Saturday. At first it’s in several chunks then it sort of comes together on Saturday morning…so the snow may linger into the afternoon on Saturday. The animation below is via NEXLAB
The data suggests rain will start things out…in the afternoon. I think the NAM is too quick on the changeover to snow during the afternoon. IF it’s pouring snow in the afternoon…this will turn into a 4″+ snow for KC easy.
The bottom line, at least to me…the earlier the snow starts sticking the bigger the amounts. IF the snow sticks at 3PM Friday…4-8″ is possible. IF the snow starts sticking at 6PM…3-6″ possible and if the snow starts sticking at 9PM…2-5″ is possible. The later we wait for sticking snow the lower the totals. Most of the appreciable sticking snow should finish during the mid morning Saturday. There still should be some snow after that though…and some additional more minor accumulations are possible into the game itself. There could be a band of somewhat heavier snow move through in the afternoon as the storm winds up and pulls away. That could be a bit more interesting during the game itself.
So my approach is that the snow starts sticking in earnest after 6PM Friday…so the way I’m approaching this is looking at how much moisture is forecast to fall from 6PM FRI>6AM SAT.
Let’s use the hi res NAM to start that conversation…
Roughly .4 to .5″ for most of the KC region..some heavier north and south.
Now I don’t think (initially) we’ll have a strict 10:1 snow ratio…1/2″ rain equals 5″ snow…we may have to work into that Friday night. So playing with that a bit…gives me my 2-4″ thought process for KC. Some upside on the MO side.
Let’s say that we’re waiting till 9PM for the snow to stick…now let’s look at the forecast moisture totals from 9PM FRI>9AM SAT…
Still near .4″ BUT there is a noticeable decrease from the SW coming up I-35. Still decent totals northern MO.
IF we’re waiting till 12AM SAT…then this is a somewhat different ballgame. I DON’T think this will happen. Here is the 12 hour total in moisture from 12AM SAT-12PM SAT.
That wouldn’t be much at all…and with temperatures near 32° appreciable accums over 2″ would be tough to come by.
So really the bulls-eye of this should be after 6PM FRI…maybe add a few hours to 9AM SAT for accumulations.
Melting…compacting of heavy wet snow…still steers me in the 2-4+” bracket.
This will be a heavier wetter snow. Great for snowman making and snowball fights but some will struggle to shovel off the driveways because of the “weight” of the snow.
I did some calculations…IF your driveway is 50 feet long and 20 feet wide…it covers 1000 sq feet. Based on that…and with about 3″ of snow on it…that 3″ of snow may have .4″ of liquid in it. That’s about .03 cubic feet. Multiple that by 1000 sq feet and you get 30. cubic feet of water. 1 cubic foot of water weighs 62.4 lbs…so multiply 62.4 cf of water by 30 and you get over 1800 lbs of snow. Just shy of 1 ton. That’s why these types of storms are called heart attack snows. There is actually some interesting write ups about these heavier wetter snowstorms that you might be interested in.
There are other factors as well…working out in the cold that also puts pressure on the heart muscle and on your blood pressure. The cold makes your arteries constrict raising blood pressure and that can strain the heart too.
We actually haven’t had one of these type snows in awhile, of any consequence I don’t believe.
Sorry for that tangent.
About the current watches/warnings etc…this should be a higher ticket item towards the east of the KC region.
More updates as needed. The GFS model is still the least snowy of the bunch. Other models are somewhat in the 3-6″ range. The Lakes region may get this one pretty good!
Our feature photo comes from Glenna Oidtman in Grandview, MO