Friday, March 8, 2019

Friday Night - Mostly cloudy. High: 40-44.

Saturday - Cloudy with rain showers starting in the early AM and thunderstorms possible. Breezy in the afternoon. High: 62-66.

 Saturday Night -  Partly Cloudy. Low 33-37.

Sunday - Partly Cloudy. High: 45-49.

Monday - Partly Cloudy. High 48-52.

Thanks to for the icons!


We had to suffer threw some cold temperatures earlier this week, but we get a warm up tomorrow. We expect temperatures to reach above average in the low to mid 60s. With the warming temperatures on Saturday brings rain showers and the possibility of some thunderstorms in the morning. The showers will move out leaving cloudy skies and winds will increase. The National Weather Service has issued a Wind Advisory for Columbia, MO to be effective from noon Saturday to midnight, with sustained wind between 20 and 30 mph and the possibility of wind gusting up to 50 mph. After Saturday the skies never completely clear out and we will see average temperatures near 50 for the start of the week. 
Forecasters: Johnston, Rojas, and Bongard
Issued: 5:00 p.m.March 8, 2019

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

The main concern for our forecast will be the rain showers, thunderstorms, if any would be severe, and wind gusts on Saturday. There were a some disagreements between the NAM and GFS with the timing of the eroding of the dry layer and the warm front on Saturday. But we decided the GFS handled it better. So that is what we looked at to forecast. At 250 mb we can see a trough approaching to the area with the jet streak south of us. The axis of the upper trough will pass over us on Saturday. This upper level flow is related with the trough at 500 mb which becomes negative tilted by Saturday at 12 Z. At that time the maximum vorticity is located over western Oklahoma, while Columbia is on the downstream side of the trough. Vorticity is being advected to the area until 18Z on Saturday when the axis of the trough crosses the state. The SPC has Columbia in the marginal risk for severe storms on Saturday, but we don't see us getting anything more then a typical thunderstorm. We are pessimistic about severe storms due to the GFS not showing strong omega forcing compared to NAM for that time, low CAPE values between 250 to 350, and no daytime heating beforehand.  Temperatures increase Saturday with SW flow starting around 12 Z and then shifting to a W flow around 21 Z. At the surface the warm front will reach the area by early morning and the cold front will pass by late Saturday, drying out the entire atmospheric column. The winds are around 40 kts in the lower level of the troposphere during Saturday due to the higher pressure gradient. The mean & spread ensemble products for accumulated precipitation agree on at least 1" of rain.

The system will move off Saturday night, so drier and colder conditions are expected. The jet streak will position itself right over central MO on Sunday. This will move the zonal flow somewhat quickly through the central CONUS with a 140 kts max jet around 18Z. On Monday the lower level flow becomes more northwesterly while the mid and upper level remain mainly westerly, but drier in general.