Joe’s Weather Blog: Christmas weather complications (SUN-12/25)

This is an archived article and the information in the article may be outdated. Please look at the time stamp on the story to see when it was last updated.

Good afternoon…as of 3:30 PM today…storms are rumbling through central KS and are moving towards the east at close to 30 MPH as a line…the individual cells though are moving much faster. Temperatures in the area this afternoon have popped into the mid 60s from KC southwards. We do have some patchy areas of drizzle out there now…but again the main area of rain is still about 100 miles west and SW of KC.

Forecast: (3:30 Update)

Tonight: Storms will zip through the area between 5:45-7:30 or so. Brief heavy rain, some near severe to severe strong winds potentially to 60 MPH and perhaps a few lightning strikes are possible. A little shower activity is possible as well behind the main line of storms through 8PM or so. Again this may impact the early part of the game. Skies will then clear out later tonight.

Monday: Mostly sunny and cooler but still rather pleasant for late December with highs well into the 40s

Discussion: (previous)

Note that the blog may be updated several times today but I wanted to get something fresh out to you on this Christmas morning.

1st things 1st though…and most importantly for now at least…

OK…now onto the situation at hand.

Radar this Christmas morning is showing some activity out there. This rain (and not snow or anything else) will be in the region at times through the late morning but then should gradually shut off for a few hours or so. Here is a look at the NWS radar from Pleasant Hill showing the latest trends and movement

This activity shouldn’t be severe…

This is sort of an appetizer to a storm system that is really starting to wrap itself up across the Rockies into the northern Plains states. This storm will create blizzard conditions there…but since it’s SOOOO far towards the north of here…we’re firmly in the warm sector of the storm and that’s why you’re going to be noticing a dramatic warm-up as the day unfolds today in the KC region from the south to the north.

The storm in the upper levels of the atmosphere is moving through the Rockies this morning.

You can tell just by looking at the satellite loop that this is a dynamic system right now…the core of this is moving towards the upper Midwest into the Northern Plains.

Rain/snow and ice will be breaking out in the northern Plains as the day moves along.

With the colder air in play towards the Dakotas…what wills will be a wind driven blizzard!

That’s wayyy up towards the north in the colder air…cold air here will not be found this afternoon as increasingly strong south winds usher in MUCH warmer temperatures and also higher dew points…more like April type weather as highs should surge into the 60s. 67° in 1922 is the record high for the date…we won’t get there but this will still be one of the warmest Christmas Days in KC weather history back to the 1880s.

The following map shows the isobars…or lines of equal pressure. This will help you find the surface storm later today and tonight as it develops into the upper Midwest.

Closer to home…watch this surface map that will be updated throughout the day. The temperatures are in RED while the dew points are in GREEN.

Those 60s to the south of here this morning will rapidly spread northwards later this morning into this afternoon. You will feel the change as the day unfolds…I guarantee it!

Note as well the dew points in GREEN. That higher moisture air is moving northwards as well and will overtake the region this afternoon especially.

So as the surface storm pulls into the northern Plains a cold front will start moving into the central plains and head in our direction. Storms will fire in haphazard fashion with that front and start racing towards the NNE and NE towards our area later this afternoon. They will be booking it at close to 50-60 MPH or faster potentially.

As I mentioned in previous blogs…the winds just above the surface will be cranking away. We may have 25-40 MPH winds near the ground…but a couple of thousand feet up it will be doubled that.

Let’s take you from about 3000′ to 12,000 feet up in increments of 3000′. Notice the strong winds…these are in knots…so roughly 50 knots equals about 58 MPH.

Those are strong winds! This will cause an abnormally high about of wind shear in the bottom 6,000 feet of the atmosphere. That wind shear may allow the storms (which may won’t grow typically as tall as they would in the spring and summer months) to show some rotation on radar. That always is concerning because you can…not saying it will set up this way…but it can help to create some fast short-lived tornadoes. There have been instances in the past with some vague similarities as one of my colleagues from the NWS pointed out last night.

That was a nasty outbreak there as tornadoes hit the metropolitan St Louis area.

She and I are both NOT saying this will happen in the same way…but we’re just alerting you that the atmosphere is going to be up to something later today and it bears watching.

Of course this is the tough part because unless they were watching the newscasts tonight…they may not know or may forget. Then with the craziness of Christmas today with family and friends…nobody is really paying attention. Then with the tailgating and the game this evening…nobody is aware of the issues that may be at hand. You obviously are aware since you’re reading the blog…but pass along this information. Don’t hype or scare anybody…just make them aware of what can happen. These would be fast hitting and short storms that are flying through the region later this afternoon.

Here is the HRRR model via IA State showing the model idea of an outcome today.

The last couple of images I want to leave you with are from the SPC. The 1st one shows the severe weather risk…

and finally a piece of data that we’ll be watching carefully. This is the SRH (Storm Relative Helicity) product and it shows the tendency of the lower level air to rotate cyclonically in the updraft part of a storm. Watch this map carefully later today when there are storms present and moving into areas of higher SRH. While there is no set in stone value for tornadoes…when the value exceeds 250 or so we pay attention to it!

It’s not a perfect predictor though…other things have to happen…but it’s data point too pay more attention perhaps.

More updates this afternoon.

Our feature photo comes from Mary Jo Seever…it was a foggy day yesterday!


Merry Christmas!


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