Current Conditions at Sanborn Field

Thursday Night: Drizzle possible, overcast. Low:34

Friday: Rain ending in the early afternoon. High: 44

Friday Night: Clouds clearing, frost possible. Low: 30

 

Saturday: Mostly sunny, warmer. High: 55

Saturday Night: A few clouds. Low: 40

 

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Discussion:

Soggy and cold conditions will close out this Thursday with light scattered showers possible overnight. A few snowflakes may mix in with the rain early Friday before precipitation finally comes to an end just after noon tomorrow. A light frost is possible Friday night as temperatures dip near freezing but conditions will begin to steadily improve over the weekend. Be sure to enjoy it with highs making a run for the 70s by Sunday, as more chances for rain arrive next week.

- Splater 

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Forecasters: Noblitt, Splater, Vochatzer

Date Issued: 04/07/2022 5:00PM CDT

Technical Discussion: 

 

    For our forecasting period, diagnostics of both the GFS20 and NAM40 pointed towards GFS20 being the model for our forecasting period. Both models were very similar in the projection of the MLSP to the 18Z surface analysis by the NWS, however when comparing the SREF and GEFS plumes to current temperatures, the SREF plumes were a couple degrees warmer than both the actual temperature and the GEFS plumes. Various combinations of the NBM, plumes, and soundings were utilized in forecasting our temperatures, precipitation, and cloud cover.

    Looking at the 300mb plot of heights, winds, and divergence, we can see an upper-level LPS is residing over southwestern Wisconsin at the time of writing. This placement of this low has forced the jet stream to divert south around it, placing a jetstreak over southern Arkansas. Little to no divergence can be observed over our region until Saturday at 6Z when the LPS has traveled far enough northeast over the Great Lakes that the upstream jetstreak from the low’s trough will reside over Missouri in a direct northerly flow. This will bring a bit of divergence before a ridge pushes its way across the Plains and into the Mississippi Valley at 12Z Sunday.

    Following this up with the 500mb plot of heights, winds, and vorticity, a large band of vorticity associated with the low to our northeast covers most of Missouri. These areas of circulation will gradually weaken and move off to our east along with the low through 9Z Saturday. Afterwhich, little to no vorticity can be seen over the Middle Mississippi Valley for the remainder of the forecasting period.

    Observing the 700mb plot of heights, winds, RH, and omega, we can see a large amount of moisture following along the LPS to over Wisconsin. This moisture, coupled with the vorticity seen previously and the slight forcing present in our omega values will give rise to some low level cloud cover as well as some light precipitation, given the lack of divergence needed for convection. This saturation will stay with us until late Friday night before continuing eastward. Following this, no significant saturation is present over mid-MO through the rest of the forecast. 

    Looking towards the 850mb plot of heights, winds, temperature, and dewpoint, we see our winds predominantly out of the northwest as the LPS transitions towards the Great Lakes tonight. Our winds will endure out of the northwest until late Saturday morning, continuing to keep our temperatures cool. Around noon Saturday the ridge passes across Missouri bringing our winds out of the southwest by Saturday night. Temperatures will begin to increase as warm air is rushed in by the LLJ. Glancing at the plot of MSLP, 1000mb-500mb thickness, and winds, some CAA can be seen over Missouri tonight into early Saturday morning. Some WAA can be seen sparsely as we proceed through the rest of the forecasting period. Soundings and the NBM indicated very light precipitation through the night, leaving anticipated precipitation totals of trace for our period.

    Future forecasters should pay attention to the strong jetstreak following closely behind the ridge into Sunday.

 

- Noblitt