Tuesday, May 7, 2019

Tonight - Cloudy. Heavy rain with thunderstorms. Low: 59-63

Wednesday - Cloudy with thunderstorms. Breezy. High: 72-76


Wednesday Night -  Cloudy with heavy rain. Low: 57-61

Thursday - Cloudy with possible thunderstorm and rain. High: 70-74

Friday - Mostly Sunny.  High: 70-74   

Thanks to IconArchive.com for the icons!

We remain in an active pattern of weather this week. Possibilities of thunderstorms persist into Thursday, however, the atmosphere may remain too stable to allow us to see any severe thunderstorms. Our main threat from the systems moving through this week would be heavy rain that would lead to potentoial flooding. Since mid-Missouri has saturated ground, it would allow rain water to pool up on the surface, creating flash flooding. This is why a flash flood watch will remain for Columbia all the way through Thursday morning.
As for tonight, we have good confidence that we will recieve some heavy rain but the likelihood of getting thunderstorms has been decreasing for tonight. Tomorrow is going to be the best shot at seeing any severe thunderstorm activity however, the confidence on the severity of these storms has also been decreasing since the atmosphere may be too stable to support severe threats. Tomorrow will be rainy and also breezy with winds gusting 30 mph but seasonal in temperatures. Thursday will be cooler compare to tomorrow but will have some lingering possibilites to see some showers or spotty thunderstorms but will move out as we make our way to the evening hours. By Friday we will clear up and finally see some sunshine.

Forecasters: Azzara, Munley
 , Browne and Hirsch
Issued: 5:00 p.m.; 6 May 2019

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

During the forecast peroid the concern is for the poitential for severre weather with primary concerns specifically with heavy rain, large hail and damaging winds;.  The WPC suggests using the ECMWF, GEFS, and NAME Nest blend, for this peroid the blend of the GFS and NAM were used leaned heavier on NAM becuase GFS was slower on the timing of the frontal passage.   

Like last week a stationary boundary is what is causing the problems with determining the potential for storms to fire up and how severe those storms could be.  The atmosphere over Columbia is more stable than the atmosphre off to our west, weak divergence aloft is not helping the situation much either.  The lack of sunlight to heat the surface really dampened the chances for any real organization to occur during the afternoon hours for any real potential of storms to fire.  Our atmosphere is drier as well according to NAM forecast Skew-Ts with a dry layer between the surface and 700mb. A moist 700mb layer with about -3mb/s of omega forcing in the column between 700mb to 600mb level is aiding the persistant cloud cover that will be seen for the rest of our afternoon and into the evening hours tonight, though some clearing for a short time by around sunset is sugested in both the GFS and NAM suggested in the column.  Massive divergence in the 250mb level moves over the area overnight, with a south, southeasterly 850mb LLJ really ramps up overnight allowing ample moisture advection and a veering column would typically suggest the potential for thunderstorms but throughout the column there is a lack of moisture near the surface a well as the mid- levels of the atmosphere and the column never entirely fills, plus there is upwards of *10mb/s of forcing for omega form the surface and little to no upward vertical motions in the mid-levels of the atmosphere.  As the stationary boundary lifts to our north as a warm front overnight Tuesday night could spark more of a frontal rain but even then confidence for rain chances tonight are low. 

Wednesay we are in the warm sector of this pesky storm system.  The breezy southerly winds at the surface are expected to be around 10-15mph.  The atmosphere tomorrow morning does appear to become more unstable, CAPE values from 12Z to 22Z are ranging form 1000-1500J/kg with minimal capping.  The best chance to see thunderstorms is going to be during the late morning and through the late afternoon hours on Wednesday.  The main concern with the potential storms is heavy downpours and at best small hail, areal flooding could be possible as there is the potential for rain howers and potential storms from 17Z-23Z Wedneday.  

Timing of when the showers and storms ending Wednesday afternoon will help determine how active Wednesday night will be.  NAM soundings indicate that the areas between the surface and 700mb remain somewhat moit druing the night Wednesday night and through Thursday morning but lack of a forcing mechanism and any upper level moisture is concerning for any potential precipitation to fall overnight.

A cold front does swing through the area at 11Z Thursdy, with that a brief shower is possible just ahead of the front as it passes through.  The storm system interacting with the area from Tuesday and Wednesday finally moves out with the passage of the cold front.  Cloudy skies to persist Thursday though as low level moisture does hang around until we finally begin to clear out Thursday afternoon.  Tuesday night through Thursday afternoon according to SREF plumes and GEFS plumes rainfall accumulations could amount to .65-.90in of rainfall.

A well deserved, quiet, spring-like day for Friday as high pressure slides south from Central Canada and settles over the Colorado/Kansas boarder .  This is just the start of a nice stretch of weather for Mid-Missouri but will differ details to a later shift.

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