Current Conditions at Sanborn Field

Friday Night: Mostly Cloudy. Low: 30

 

Saturday:  Increasing clouds and gusty winds. High: 53
 

 

Saturday Night: Overcast with light freezing rain. Low: 22

  

 

 

Sunday: Partly cloudy with gusty winds. High: 27

 

Sunday Night: Partly cloudy with light winds. Low: 16

 

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Discussion: 

The weekend will start off unseasonably warm with gusty winds from the south on Saturday. A cold front passing from the northwest will drop temperatures back down to below freezing with a chance for light freezing drizzle Saturday night into Sunday morning. This may make roads slick on bridges and overpasses. Sunday will remain cold and cloudy with gusty winds from the north.

- Sausen

 

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Forecasters: Sausen, Thomas, McGuire

Date Issued: 1/27/2023 4:20PM CDT

Technical Discussion: 

The main concern of this forecast is precipitation Saturday night into Sunday, and strong winds Saturday and Sunday morning. We used the GFS for our forecast, as it handled this morning’s sleet event much better than the NAM.

A large-scale longwave trof is dominating most of North America, centered over the Hudson Bay, while a strong jet streak oriented SW to NE is currently situated from TX all the way up into the Mid-Atlantic region, with a separate weaker maxima from E KS into MO. As both streaks exit the regions, a new jet streak is progged to strengthen and slowly move north, stretching from the OH River Valley into E KS early Saturday morning into Sunday, and an additional jet max is forecast to form over TX Saturday night, leaving plenty of zonal upper level winds over our forecast area.

At 500 mb, the trof that affected our area this morning becomes a lot more apparent, stretching from MN positively tilting down into MO, though it should quickly exit the region by this evening. By late Saturday night into Sunday, a second shortwave is progged to enter the forecast region, with significant PVA in its tow until Sunday at 12Z.

At 700mb, moisture associated with this morning’s shortwave quickly exited the area, not forecast to be replaced until 03Z Sunday, with a plume of moisture overspreading the forecast area until about 12Z Sunday.

Strong moisture transport looks to push a plume from TX up into MO, meeting a frontally-driven area of moisture at the 850mb level Saturday afternoon, persisting well into Sunday evening. WAA starting tonight looks to overtake our forecast area, before being replaced by CAA around Sunday at 09z. Otherwise a strong LLJ out of the SW is mixing to the surface as forecasted, and is progged to persist into Saturday night, keeping winds at the sfc gusty.

At the surface, our forecast area is situated in the col between the two lows off to our northeast and west, and the high over the Southeast, keeping sfc winds light and variable until the western low takes precedence Saturday morning.

Our main concern is the possibility of light precipitation Saturday night into Sunday. The DGZ looks to remain rather unsaturated through the period of concern, with the top of the moist layer remaining around -8C. This will most likely result in a light rain transitioning over to freezing drizzle by 09Z, although with a slight amount of vertical ascent from the advancing front there may be a bit of snow mixed in during the morning hours. QPF should be minimal, with only minor travel impacts expected.

As for our temps, we should stay slightly above climo for tonight, and in the 50’s tomorrow. Cold air should make its way into our area Saturday night pushing us into the mid to upper 20’s all day Sunday.


- Thomas