Current Conditions at Sanborn Field

Thursday - Growing clouds throughout the day. High: 56 - 60

Thursday night - Overcast. Low: 38 - 42.

Friday - Rain beginning in the afternoon. High: 52 - 56.

 

 

Friday night - Rain. Low: 42 - 46.

Saturday - Rain likely, ending in the evening. High: 48-52.

================================================================== 

 Thanks to IconArchive.com for the icons!

Discussion: 

We have another rainy end of the week in store for us in Central Missouri.  While Thursday will remain dry, there will be increasing coverage of clouds throughout the day today in advance of a low pressure system that will be supplying the area with rain.  Rain totalling up to about 0.5 inches can be expected through Saturday.  It is worth mentioning that an isolated rumble of thunder or two could happen, but widespread storms are unlikely. 

 

==================================================================

 

Forecaster: Gasch

Issued: 10:45 AM CDT 15 April 2021

 

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

 

The 06Z GFS run was used for the bulk of this forecast due to its better handling of both the location and the intensity

of the low pressure system that is currently to the west of our area.  

The 250-mb level clearly shows the jet which is situated directly to our south. The jest stream shifting to our south is

responsible for the cold front that passed through our area earlier this week. Throughout the day on Thursday, the

general flow is more or less directly out of the west. The main feature to look for on Thursday is a slight ridge that will

build throughout the day. Once that ridge flattens out on Friday, much higher levels of divergence will be found 

over Missouri. Also, the winds will shift to a more south-westerly direction which should lead to warmer temperatures

later in the weekend. 

Two low pressure systems can be seen swirling across the country at the 500-mb level. The fist low is to our northeast

over the Great Lakes region. The second low, currently sitting over the Inter-mountain West, will be impacting our

weather for the remainder of the week. While there is not much vorticity over our area today, that will begin to change

as the low to our west gets closer to our area. Vorticity will begin to increase on Thursday evening. Winds will start

to veer in advance of the low at the 500-mb level which should lead to slightly warmer winds if not warmer temperatures

as well. Vorticity levels will remain high throughout Friday and Saturday.

 

As we begin the day on Thursday, our mid-levels are fairly dry. The drying trend at the 700-mb level will continue 

throughout Thursday. We will begin to receive moisture at this level in advance of the expected low pressure system.

Once the air becomes saturated, it will stay at very moist levels until the low pressure has passed through our area.

The level will begin to dry out again Saturday afternoon. Levels of omega will also increase. These omega values will

correspond with the increase in moisture. While there is some variability in the models, the GFS has our peak values of

omega reaching our area around 00Z Saturday or 7 PM Friday evening. While the omega values will then begin to taper

off, vertical motion will remain in the area through Saturday morning. 

The 850-mb level tells a similar story as the 700-mb level. While we are currently dry at the 850-mb level, moisture 

should be expected to move into the area during the afternoon hours of Thursday. Once the low, and its accompanying

moisture, reach central Missouri, this level will remain saturated throughout the duration of the forecast period.

Though the bulk of the omega associated with this low pressure system will be mostly to our south *near the Missouri-Arkansas

border), we can still expect our highest levels of vertical velocity during the evening on Friday. The vertical velocity and

moisture at both the 700- and 850-mb levels will contribute to cloud cover in advance of the low.

At the surface, the fron that passed through yesterday is now ell to the southeast of Missouri. The current dry slot 

located over Missouri can be clearly seen on the visible spectrum on the GOES-16 satellite.

The end of the week and into the weekend will, once again, be rainy and dreary. The low pressure system that will be moving

through the area in the next couple of days apprears to have a negative stacking/tilting to it. This negative tilt

should lead to a strengthening of the system. The streghtening can be seen on the heightmas at various levels until the low

is reabosorbed by the main 500-mb level flow. Rain can be expected to begin in the early afternoon on Friday, and will likely

continue though late Saturday evening. While there is some CAPE in the area on Friday, there is not enough for any significant

amount of convenction. Therefore, while it is not expected, don't be surprised to hear any isolated rumbles of thunder.

The area should expect between 0.1" and 0.5" of rain throughout Friday and Saturday.