Joe’s Weather Blog: Sneaky holiday week systems (SUN-12/20)
Good afternoon and a warm and windy day in KC. Low clouds have now moved into the region as gulf moisture is streaming northwards. Temperatures are in the 50s again for today and odds are we’ll be in the 50s tonight at 12AM for a midnight high for the 21st. Assuming that happens…it would be the 14th day with highs >=50°. The record is 22 back in 1889…we won’t get there this December although a few more are certainly likely.
Tonight: Cloudy with rain showers developing. Mild this evening and overnight through 4AM and breezy too but the winds will start to drop off a bit this evening. Lows in the 50s through 3-4AM then it will drop quickly.
Tomorrow: Temperatures will continue to drop through daybreak and into 9AM Monday or so and eventually drop into the 30s. Rain chances will fade away before daybreak. Winds will be from the NW at 15 in the morning then start to lighten in the afternoon. Temperatures tomorrow afternoon will only be around 40-44° with clouds thinning as the afternoon moves along.
Tuesday: Mixed clouds and sunshine but milder again with highs back into the 50s. Breezy as well.
Temperatures this week will be a bit on the tricky side and may vary a bit from forecast to forecast. Fast moving disturbances in an increasingly strong SW flow aloft will help to give us periods of clouds and also allow some fast moving fronts to move through the region impacting temperatures. So if you see the numbers vary a bit from day to day…that’s why…timing those little buggers will be tough to do.
One of these disturbances will be coming through overnight tonight. Take a look at that disturbance by going up into the mid-upper levels of the atmosphere (about 18,000′ up) and take a look at the 500 mbs forecasts. What I want you to look for is that small-ish “U” dip near the central Rocies coming out through the Plains overnight tonight. That is the disturbance that will create more lift in the atmosphere overnight allowing the formation of showers later today and tonight.
at the surface there will be a cold front moving through…and you can see that as well on the RAP model.
Notice the showers developing…there are some signs in the atmosphere that there could even be a bit of weak convection as well…so perhaps some isolated thunder could occur as well.
The cold front will sweep away the warmer air and allow cooler temperatures to move in…really it’s just a brief incursion of seasonable air it appears. This will rotate away from the area Monday night and allow the winds to switch back towards the south on Tuesday bringing a rapid return of milder conditions on Tuesday ahead of the next wave/front moving through on Wednesday with additional rain chances for the middle of the week.
This mid-week system will create more lift which should allow for more rain showers to develop and move through area on Wednesday. A persistent south wind Tuesday night will keep temperatures up and we still may be around 50° (perhaps a bit higher) or so on Wednesday morning before dropping Wednesday afternoon as cooler air spills back into the area.
That “cooler” air will be around on Thursday as well. A note about Thursday…the winds aloft are going to be going pretty goo from the WSW to the ENE. There may be a couple of small little waves zipping through. Interestingly the EURO is trying to generate some VERY light precip in central KS overnight Wednesday into early Thursday that would be moving towards the ENE…it should fall apart before it gets into KC but I’ll keep an eye out. I don’t think the atmosphere would be cold enough for snow even IF that precip held together as it moved our way…but again there is a little wiggle or two to watch.
We then go back into the warmer air Friday into potentially Saturday…before colder air (more seasonable) comes in over the weekend at some point…Christmas may be a bit cloudy but it should be warm 50°-60° through the region) and we should stay mild even through Christmas night it appears. The bigger rain chances should move in over the weekend at some point…
More on that future storm (which appears to be all rain again) as the week moves along. The model solutions have been chaotic at best. ALL the models can’t figure out what to do with NEXT weekend storm…which may linger into the early part of the last week of December. So there is really no point in writing too much and/or speculating too much about that. My feeling is that the model portrayals are not right (they never are from this far away anyway) but there is more doubt than usual in my mind about how this plays out.
Have a great Sunday afternoon and I’ll update the blog again on Monday morning.