KANSAS CITY, Mo. — I’m off for the rest of the week but I couldn’t NOT write something about the craziness of today’s weather in this part of the country and elsewhere.
Things are/may be happening today (in December) that we haven’t seen before. For that reason alone, we’re diving in a with a stat-heavy blog to show the uniqueness in what’s going on. So let’s dive in.
Today: Variable clouds with extreme wind. High wind warning in effect. Gusts to 60 mph are possible. Extremely warm and “muggy” by winter standards. Highs 73-76 degrees. The daily record will be broken by the time you read this (68 degrees set in 2002) and the monthly record for December is attainable as well: 74 degrees, set on Dec. 3 2012, Dec. 5 2001, and Dec. 6 1939. Storms/quick-hitting rain is likely between 5-7 p.m. in Kansas City, earlier to the northwest and a bit later to the southeast.
Tonight: Blustery and turning seasonable with lows by daybreak in the lower 30s (still above average).
Tomorrow: Sunny and pleasant with lighter winds. Highs near 50.
Friday: Variable clouds with highs in the lower 50s.
I don’t even know where to start…
Records warmth, record dew points, record winds, tornado risks, the end (hopefully) of an almost month-long dry spell for Kansas City… and the list goes on and on. So let’s start with the winds, as a high wind warning is in effect. That is pretty uncommon for the winter in Kansas City. There have only been 18 or so issued by our local National Weather Service office going back to 2005.
All the counties in the darker orange/brown are the counties with warnings. Areas southeast of Kansas City are under a Wind Advisory. Gusts in Kansas City may be 50-60 mph or more.
A strong developing surface storm in the western Plains will be moving through Nebraska, Iowa and Wisconsin as the day moves along. Here is the current pressure pattern. The black lines are isobars (lines of equal pressure):
Notice ALL the isobars along the I-35 corridor. When they’re tightly spaced like that, that shows a large change of air pressure from one part of Missouri to another. The same goes for almost the entire Plains and upper Midwest as well. These tightly packed lines of equal pressure represent a strong pressure gradient force.
Strong winds result in large pressure gradient forces. Voila! Air also moves from higher pressure to lower pressure. This will be an intense storm that moves through… as a matter of fact, it could break some records for the lowest air pressure in December for states to the north of here. We have to go back to the late 1940s to find something comparable.
The area most vulnerable to this potential is in Minnesota.
All the winds from the south are bringing in highly unusual, high dew points to the area. Dew points this morning are approaching 60 degrees.
Here are the highest dew points reported during the winter season (DJF).
The magic number appears to be 63-degree dew points back in late December of 1984.
How about the stronger winds… the highest wind gust reported in Kansas City during the winter (DJF) season is 55 mph. That may get broken.
And in December, going back to KCI opening:
In looking back at the downtown airport records, I can’t find anything before that timeframe that exceeds KCI. So if we get to 50 mph or higher, we get a record.
So about the temperatures: a daily record is a guarantee. The second this month as a matter of fact. Also the second day with highs in the 70s this month. That has happened before, but it too would tie a record.
Here are the highest December temperatures:
In terms of the number of days 70 degrees or higher for December:
So today will tie us for two. Again, rare air that we’re breathing for that stat.
Elsewhere these records are vulnerable today:
Roughly from Michigan to Texas:
So let’s look at this storm as it intensifies at the surface and comes out of the Rockies and spins up in the northern Plains.
All the dynamics and the intense winds aloft create the risk of severe storms, even in December (up there especially).
Let’s look at the strong winds this thing will be generating at 5,000, 10,000 and 18,000 feet (approximately).
A knot is equivalent to 1.15 mph. So 25 knots is about 28 mph. 50 knots equals about 58 mph, and 100 knots is about 115 mph. It’s impressive to see the maps above.
That leads us to this: The risk of severe weather.
See that red up in Iowa and Minnesota… that is a moderate risk of severe storms. In December. That has never been issued up north before. What’s also fascinating is that the area was hit by a 12-18-inch snowstorm this past Friday. Five days later, nighttime tornado risks developing. This is the first time the Storm Prediction Center has issued a moderate risk of severe weather in Iowa, Minnesota and Wisconsin in December!
There has never been a tornado in recorded weather history in Minnesota in the winter (DJF) months.
Just for giggles, here is a breakdown closer to home:
And a close up of the Kansas City region:
That Ray County tornado was back in 1960 and an F2, and the Platte County one was back in 1975.
The tornado risk up there is connected to these strong winds aloft and the change in the wind direction as you go up in the atmosphere. It’s a scenario where there is somewhat limited instability, but whatever forms may be “spinning” so this could put down some tornadoes. If that happens, they’d be moving at an incredible 60-80 mph! At night no less. Crazy to see this again as surveys continue in the south of the region for what happened this past Friday night.
For Kansas City, the main risk of rain/storms will only last about 30 minutes at any one place and seem to be roughly in the 5-7 p.m. time frame. Here is the HRRR model evolution. For timing, 21Z is 3 p.m., 0Z is 6 p.m., and 3Z is 9 p.m.:
Whatever happens, it will be quick. And while the winds ahead of the storms/showers may be gusting to 55 mph, the winds with the storms may be close to 60 mph… you really shouldn’t be able to tell a difference.
The hail risk is low, but I can’t rule out something “spinny” up in northern Missouri either. Again, a lot of things happening so quickly.
Oh and for the snow prospects… well, this isn’t a good sign. GFS total snow into the 30th: