Thursday, May 7, 2020

Thursday Night - Rain. Low: 46-50

Friday - Possible rain early. Decreasing clouds. High: 54-60

Friday Night - Becoming clear. Low: 32-36

Saturday - Mostly sunny. High 58-62

Sunday - Mostly cloudy. High: 58-62

 Thanks to for the icons!

A cold front and low pressure system will bring rain all throughout the midwest tonight. Showers will persist into early tomorrow morning. After that, high pressure will set in and clouds will gradually decrease. However, strong northerly winds will bring cool air after the cold front passes early on Friday resulting in temperatures Friday night dropping substantially below typical May nights and even approaching freezing. When the winds have slowed and sunny weather returns on Saturday, temperatures will quickly rise into the high 50's and low 60's. There is a very small chance for some drizzle Saturday night. Otherwise, some clouds will return as a result of a low pressure system to the north on Sunday. Temperatures will remain fairly seasonal. CL
Forecasters: Lieberman, Ritter
Issued:  5:00pm: May 07, 2020
Technical Discussion (The nerdy stuff we are discussing in class)

The WPC recommends a blend of the GFS and ECMWF. For this reason, we used these models as well as SREF plumes and the HRRR for short range precipitation monitoring. CL

At 250MB, a closed low is located over northern Ontario. A positive short wave trough also extends from Wyoming to North Dakota. A jet max is also located over Michigan, Lake Michigan, and northern Indiana. At 500MB, the shortwave trough is much deeper, indicating a surface low, and has substantial circulation associated therewith. At 700MB and 850MB, there is significant moisture surrounding the low pressure system up stream but dry air over the greater Missouri area currently above 850MB. Below, saturation is significant resulting in low cloud decks and overcast skies. This is confirmed by visual observation. CL

Tonight, the aforementioned low pressure system will track into Missouri. A cold front associated with it will bring showers in Columbia and convective cells to pop up to the south. 500MB vorticity shows significant circulation that strengthens as the system reaches Missouri. 700MB and 850MB moisture and UVM is equally substantial. The LLJ max will be located over northern Texas and Arkansas tonight, allowing for moisture to be advected in. Soundings from all models show significant support for showers through the night and into the early morning. SREF plumes support this with the mean QPF just below an inch. CAPE is almost certainly insufficient for thunderstorms.

A few hours after cold FROPA, when the rain has cleared out early on Friday, northerly gusts will reach high speeds moth at the surface and up to the mid levels. This will allow for CAA that will persist throughout the day. The effects of this will be shown overnight as mostly clear skies further allow for cooling and temperatures drop to near freezing.

Saturday, a long wave ridge will allow for high pressure to set in. Dry air from the north will be advected in as well. Limited moisture aloft and mostly clear skies allow for radiational heating to bring temperatures back to near average for early May. Saturday night, a shortwave trough embedded in the ridge will track north of Missouri into Iowa. A surface low associated with this system make precipitation possible. However, this will more than likely be limited to the north of Columbia. Soundings and SREF plumes show a small chance for trace precipitation--likely drizzle--but even that is unlikely. Otherwise, clouds will return on Sunday. These will be somewhat limited and likely low level. Temperatures will be similar to Saturday.

No comments:

Post a Comment