Tuesday, March 12, 2019

Tuesday Night - Overcast. Increasing showers in the evening. Low 48-52.

Wednesday - Cloudy with showers and possible thunder. Windy. High 64-68.

Wednesday Night - Cloudy, rain decreasing into evening then clearing skies. Low 48-52.

Thursday - Mostly sunny & breezy, then increasing cloud cover in evening. High 52-56.

 Friday - Mostly cloudy.  High: 40-44.

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It is finally feeling like spring time here in Missouri and with that means warmer temperatures but it also means rain. The rest of this week is going to be right on target as we see the next few waves of active weather come through the area. This active weather started today as we headed into the late afternoon hours and continue as we head into evening and overnight hours. This rain should remain light to moderate. However, the heavier rain will be coming on Wednesday afternoon for the next wave of precipitation. Wednesday's system will be stronger, brining with it heavier rain, windy conditions and the possibility of a few rumbles of thunder, however, the main thunderstorm threat will stay to our south. We will stay warm as these systems pass us to our north. Our highs for Wednesday will be in the mid to upper 60's. Rain will likely last until Wednesday night and then skies will finally start to clear out overnight. Thursday will be our next glimpse of sunshine during the work week but breezy conditions will persist throughout the day. We will cloud up as we head into Thursday night with a slight possibility of showers, however, confidence for this is still fairly low. Friday will be mostly cloudy and cooler, with highs in the lower 40's.
Forecasters: Azzara, Munley and Brown
Issued: 4:30 p.m.March 12, 2019

Technical Discussion (The nerdy stuff we are discussing in class!)

During our forecast period our primary focus is on the strong storm system that is currently siting in the Southwestern CONUS.  The model of choice for this shift is the GFS primarily per the WPC. 
Southwesterly flow in the upper levels of the atmosphere pairing with upper level divergence and decent moisture in the column calls for rain beginning around 20Z.  Overnight Tuesday the column continues to stay saturated for most of the evening and strong omega forcing at times will promote heavy rain at times but more of a moderate rain event for the most part.  A few flashes of lightning and rumble of thunder can’t be ruled out with MUCAPE values ranging from 150-200J/kg being observed at 03Z Wednesday.  
On Wednesday morning, a lull in the rain showers is expected from about 11Z to about 17Z, but if there was any precip to fall, it would be light in nature.  The break in the rain is due to a dry layer in the column from about 850mb to about 600mb, a low cloud deck is very probable tomorrow during the break in the action. Towards the afternoon hours on Wednesday will be the main event.  The next storm system will be approaching us from the southwest tracking to the northeast.  This low pressure system is a strong one, as the system begins to approach it will pass over us to our northwest over the Nebraska and Iowa border.   The central pressure of this system continues to drop and model guidance has the central pressure at 990-985mb by the time it reaches the NE/IA boarder.  This system will be occluded north of us by 18Z Wednesday but the belief is that we will be in the warm sector of this system and temperatures will continue to climb. Rain persists throughout the afternoon Wednesday due to a fair amount of lift and strong WWA aloft.  Along with the moderate to heavy rain showers at times, the winds will be ramping up as well amid a tightening pressure gradient.  Model soundings have wind speeds mixing down to the surface tomorrow afternoon anywhere from 15-20mph and gusting to about 30-35mph.  The strong winds are due to the system passing but also with the low level jet that will be over us and with the passage of the cold front, winds will continue to be breezy. 
The cold frontal passage will occur about 22Z-23Z Wednesday and precip will begin to subside around then.  Another cold frontal passage is to pass through the area from the same system early Thursday morning.  Sunshine returns to the area Thursday but strong winds persist throughout the day, with sustained 20-25mph and with gusts to 40-50mph possible.  This system will take a day or two to get out of the area. The LLJ associated with this strong cyclone is one of the reason for the strong sustained winds and strong wind gusts Wednesday and Thursday.  On Friday, things begin to quiet down, as the column remains dry.  On Friday temperatures will be below normal but winds begin to die down and sunny skies return to the area just in time for your St. Patrick’s Day weekend. 

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