Monday, December 6, 2021

 

Current Conditions at Sanborn Field



Monday Night:
Becoming Cloudy. Low: 27


Tuesday:
Cloudy. Isolated afternoon snow flurries. High: 37


Tuesday Night:
Cloudy. Low: 28

Wednesday:
Clear. High: 48


Wednesday Night:
Partly cloudy. Low: 37

 

Thanks to IconArchive.com for the icons! 

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Discussion:
 

Winter precipitation in the forecast? "Snow" way! The trend of cold winds will continue into tonight as we will reach a low of 27. Clouds will begin moving in and the winds picking up to less than 10 mph and start shifting to become southeasterly by Tuesday morning. Tuesday's winds will remain about the same as we reach a high in the mid-upper 30s. Clouds will be rolling in and we can expect to see some isolated snowflakes in the mid-afternoon. However, nothing is expected to accumulate. Winds are expected to slow slightly and the sky to clear up Tuesday night with a low in the upper 20s. Wednesday will be mostly clear with light winds from the west and a high of 48. A few clouds can be seen making their way back into the area on Wednesday night and winds will become southeasterly and gain in strength, keeping our low at 37.

-Alexander


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Forecasters: Alexander, Gromada, Gotsch

Date Issued: 12/06/21 5:00 AM CST

Technical Discussion:    

The first full week of December is making its mark with blustery winds and some flurries. Over the weekend, a trough moved into the region and began cooling off the areal temperatures. We mainly relied on how the models were handling this feature and noticed that the NAM was keeping better track of it overall. However, the surface temperatures that the NAM was outputting seemed too low to realistically occur, so we consulted with the NBM and GEFS plumes for the temperatures. To aid in forecasting the upcoming precipitation event, the NAM NEST was also used.

Currently, there is a low pressure system near Hudson Bay. This system created the trough that brought our current cool temperatures and is moving east. By moving east, the upper level jet stream is becoming more zonal, still from north of the Rockies. There is also a strengthening low pressure system off the coast of the Pacific northwest, north of the jet stream. This low pressure system is pushing south along the west coast and will eventually reach the southern coast of California.

As the low pressure system travels south, it will become a cutoff low and split the jet stream. The effect of this will be two jet streams, one that is weaker and will continue flowing north of the Rocky Mountains; the other, a stronger stream, will flow over the Four Corners region. The flow from the north will bring some moisture to the Great Plains and Midwest while the flow from the Four corners will provide some mid-level negative omega Tuesday afternoon into Tuesday night causing precipitation to occur. With these features we can expect to see some flurries tomorrow, but nothing accumulating.

Late Tuesday night and into Wednesday morning, the Four Corners flow is pushed out of the area by another longwave trough connected to the Hudson Bay low pressure system. This trough will promptly be followed, and pushed out, by a ridge from the Four Corners region. 

Throughout the forecast period, winds tend to stay southerly and light, with some exceptions. The first of which is our current winds, which will veer overnight and begin coming form the southeast. The second exception will be late Wednesday night; once the winds shift from the southeast, they could start gusting up to 20kts.

The next forecasting shift should watch the winter precipitation for Tuesday afternoon, as it may simply not occur as there is a large dry layer underneath it. 

-Alexander

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