Monday, April 22, 2019

Monday - Mostly cloudy skies. An isolated afternoon thunderstorm is possible. High: 76-80.

Monday Night - Skies becoming cloudy after midnight. An isolated evening thunderstorm is possible. Low: 48-52.

Tuesday Cloudy Skies. An isolated shower is possible. High: 62-66.


Tuesday Night - Skies becoming partly cloudy after midnight. An isolated shower possible before midnight. Low: 46-50.

Wednesday  - Becoming mostly clear. High: 68-72.

Thanks to for the icons!

Beautiful weather that Columbia enjoyed this past weekend will not be sticking around into this coming week. While temperatures will still remain seasonable for mid-April, they will drop considerably from the 80s that Sanborn recorded Sunday afternoon. Clouds will continue to build in throughout the day Monday, but not before temperatures potentially reach 80. Left the possibility for an isolated thunderstorm Monday afternoon into Monday night. Tuesday, skies become completely overcast with the possibility for isolated showers remaining. Tuesday temperatures will be considerably cooler only reaching into the mid 60s. Skies will partially clear out by Wednesday with temperatures rebounding into the low 70s.

Forecasters: Travis, Ritter, and Hirsch
Issued: 10:00 a.m.; 22 April 2019

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

With an active period taking shape over mid-Missouri for the next few days, the main forecast issues will be temperatures and whether or not Columbia sees any precipitation Monday afternoon and evening and then again during the day Tuesday. With the WPC model diagnostic suggesting the use of a general model blend of forecasts, the GFS was used most heavily in the making of this forecast. Also used were the HREF and SREF.

The synoptic setup presented by the GFS hints at marginal, albeit nonzero, chances for precipitation. At 250 hPa, the GFS depicts a 110-kt jet core centered over the US-Mexico border, with another jet core developing across the US-Canada border. Some divergence will exist aloft over mid-Missouri, especially between 15Z Tuesday and 00Z Wednesday, but the stronger and longer-lasting divergence aloft will remain to our south over the Red River Valley. The GFS also shows a shortwave trough and associated vort max at 500 hPa moving from the Desert Southwest into central Texas by 00Z Thursday. At 700 hPa, the GFS shows upward vertical motion present over mid-Missouri through about 21Z Tuesday, but most of the moisture at 700 hPa will move in between 21Z Tuesday and 06Z Wednesday, a period during which the GFS shows downward vertical motion. At 850 hPa, the GFS produces a weak southwesterly 30-35 kt LLJ overhead through 00Z Tuesday, after which the winds will weaken and back to the northwest. At the surface, the GFS shows a low pressure center over southern Nebraska that will move through the Upper Midwest and into Canada by 09Z Tuesday, with high pressure building in behind.

For Monday and into Monday night, GFS Skew-T's show saturation beginning near 200 hPa between 21Z today and 00Z Tuesday, progressing down to 500 hPa by 12Z Tuesday. This has led us to believe clouds will be on the increase, especially this afternoon, with skies likely becoming overcast by 00Z Tuesday. Additionally, GFS Skew-T's show 500-1000 J/kg of CAPE between 18Z today and 06Z Tuesday, suggesting energy is there. 06Z HREF ensemble reflectivity shows a thin band of showers and thunderstorms developing over mid-Missouri around 21Z, pushing through by 00Z Tuesday. Additionally, roughly 20 percent of SREF members produce measurable precipitation between 18Z today and 06Z Tuesday. Therefore, we have mentioned a chance of an isolated thunderstorm this afternoon and evening. As for temperatures, afternoon highs will be a bit cooler than yesterday's due to the increase in cloud cover. For overnight lows, mid-Missouri should experience a pretty sizable drop do to the passage of cold front, as evidenced by backing winds between 06Z and 12Z Tuesday.

For Tuesday and into Tuesday night, GFS Skew-T's continue to show a saturated layer between 200 and 500 hPa, suggesting cloudiness will continue. Between 21Z Tuesday and 03Z Wednesday, this layer saturates down to roughly 700 hPa. The GFS does print out up to one tenth of an inch of precipitation during this period, but with a dry layer remaining between 700 hPa and the surface during this period, we have hesitated to mention anything other than a slight chance of an isolated shower Tuesday and Tuesday evening. The saturated layer will shrink between 06Z and 12Z Wednesday, beginning a gradual decrease in clouds during that time. As for temperatures, with overcast skies and flow switching from southwest to northwest at the surface between Monday and Tuesday, we expected afternoon highs to be 10-15 degrees cooler Tuesday than they will be Monday. As for lows, with cloud cover persisting through most of the night, lows shouldn't be much cooler Tuesday night than they will be Monday night.

For Wednesday, GFS Skew-T's show the saturated layer continuing to break up during the morning, becoming very shallow (only at 200 hPa is the column saturated) by afternoon. This leads us to believe that skies will become partly sunny during the day Wednesday. With the sun coming out during the day Wednesday, temperatures will roughly be 5-10 degrees warmer than those of Tuesday.

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