FXUS63 KUNR 111721

Area Forecast Discussion For Western SD and Northeastern WY
National Weather Service Rapid City SD
1021 AM MST Mon Dec 11 2023

135 AM MST Mon Dec 11 2023

- Cold front will bring light snow to the northern Black Hills and
southwestern SD today and Tuesday.

- Dry with above average temperatures through the rest of the week,
with elevated fire weather conditions at times.


.DISCUSSION...(Today Through Sunday)
Issued at 135 AM MST Mon Dec 11 2023

A Canadian low pressure system is dragging a cold
front into the northern US. Satellite imagery shows mostly clear
skies across the CWA, with increasing clouds from the northwest. At
the surface, winds are light and southwesterly, and temperatures are
in the 20s and 30s.

As the cold front slides through the CWA today, northwesterly winds
will become breezy (15-20 mph with gusts around 30 mph).
Additionally, moisture advection combined with some weak
frontogenesis may allow for some light snow showers. Froude number
briefly supports upslope-enhanced snow over the northern Black Hills
this afternoon, with an inch or less of accumulation expected. As
the front sinks south, another area of snow along the baroclinic
zone may develop Tuesday, bringing minor accumulations to
southwestern SD. Latest ensembles are even less optimistic than
yesterday's on the chance of greater than an inch of snow there.

Tuesday's temperatures will be the coldest of the week, but with
highs still in the 30s. Temps will warm back into the 40s and 50s
for the rest of the week, as split flow develops and upper ridging
dominates our weather pattern. A couple of clippers could bring a
brief cooldown with gusty winds Friday and Sunday, but ensembles
continue the dry forecast through the weekend and into next week.


.AVIATION...(For the 18Z TAFS Through 18Z Tuesday)
Issued At 1014 AM MST Mon Dec 11 2023

AREAS MVFR/LCL IFR CIGS are expected over parts of northeastern
Wyoming, the Black Hills, and far northwestern South Dakota this
afternoon and evening as a front crosses the region. Spotty
-SHRASN are possible this afternoon across northeastern Wyoming
 and the Black Hill with LCL MVFR/IFR CONDS. AREAS IFR CONDS in
-SN are expected over parts of northeastern Wyoming and far
southwestern South Dakota after 12Z on Tuesday morning.


Issued At 135 AM MST Mon Dec 11 2023

Periods of mild and breezy weather are expected this
week, particularly Thursday and Saturday. Combined with dry
conditions, fire danger will become elevated.