Wednesday, December 7, 2022

 





Wednesday:
Mostly Cloudy. High: 50

Wednesday Night:
Increasing Clouds. Rain Late. Low: 42


Thursday:
Morning Rain. Clouds stick around. High: 49

Thursday Night:
Cloudy. Low: 45

Friday:
Chance for light morning rain. Mostly Cloudy. High: 47

 

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Discussion:

Things look dreary for the last few days of classes! Finish strong Tigers! 

Temperatures will remain steady, with our highs and lows remaining in in the 40s and the chance for rain returns! A soaking rain is looking likely Wednesday night and Thursday morning as a weak system moves in from the southwest. A front moves through Friday morning bringing a slight chance for showers and falling temperatures throughout the day.

-Russell

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Forecasters: Russell, Shaw

Date Issued: 12/07/2022 9:00 AM CST

Technical Discussion:
 

The remainder of the week looks to be rather deary and mild. Cloud cover is expected to stick through the week with a soaking rain tonight and tomorrow morning. For this forecast, we favored the GFS and EURO over the NAM due to consistency with timing of the the shortwave bringin our precipitation and low placement on Friday. 

In the upper-levels, the sub-tropical jet is situated overhead and just to our north placing is in a consistent westerly flow through the entirety of the forecast period. A weak shortwave trough is ejected from the Rockies Wednesday evening and moves northeast bringing an area of increased divergence to the forecast area early Thursday morning. As it exits to our northeast, the sub-tropical jet sags south before setting up directly overhead with strong southwesterly wind. In similar timing with the shortwave, we see an increase in vorticity 06z Thursday that slowly moves to our northeast. Following the Thursday event, we see a closed low develop near the KS/NE boarder. This system will remain to our north, but it does bring some weak vorticity Friday morning. At this level we can see the culprit for our current pattern, a large blocking high anchored over the gulf is locking the sub-tropical jet over the central US keeping us in this quasi zonal flow.

In the mid levels, that shortwave noted in the upper levels can be seen more clearly as it moved into the forecast area this evening. We begin to see increased moisture at the 700mb levels as our winds become southwesterly as opposed to the westerlys we are seeing now. This level is where the NAM differs greatest from the global models as it wanted to quickly move the closed low towards the Great Lakes, while global models agreed on it stalling over the Corn Belt. Towards the 850mb levels, we see our moisture stick around longer with humidity >90% this evening through early Friday morning. This paired, with the weak diffluent trough supports the idea for widespread slow moving precipitation to overtake the region 00z - 15z Thursday. Despite lower moisture at the 700mb levels, the weak cold front associated with the low over Iowa Friday morning does support the potential for some light rain showers.

At the surface, the air is already near saturation with temperatures in the 40s and dew points being only a few degree behind. A surface warm front associated the shortwave is gradually shifting north this afternoon. Where this front sets up will decide where the area of heaviest rain will fall and current indications suggest across the Ozarks. This will allow rain to develop along and just north of the front tonight into tomorrow. Overall, we expect .25" to .5" of rainfall with areas to our south potentially receiving upwards of 1" of rainfall. We then see a surface low develop off the mountain west and move into Kansas and then northwestern Missouri. This will aid in lifting the warm front north, allowing us to breifly warm Friday before a cold front quickly moves in. It should be noted, that with the weak southerly winds as the WF passes, we will see an increase in surface moisture as well. Assuming winds remain calm, dense fog remains a concern for Friday morning before the CF moves through the area. With the timing of the cold air Friday, we expect to hit our high temperatures early in the morning with temps cooling off throughout the day.

 

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