107 
FXUS63 KUNR 070809
AFDUNR

Area Forecast Discussion For Western SD and Northeastern WY
National Weather Service Rapid City SD
209 AM MDT Sat May 7 2022

.DISCUSSION...(Today Through Friday)
Issued at 204 AM MDT Sat May 7 2022

07z surface analysis had low over central MT, which was a 
reflection of shortwave energy moving into ID per early morning 
water vapour loop. Low had cold front into ID and trough into 
eastern WY.

Today/tonight, shortwave moves into the northern plains on 130kt 
jet streak as surface low deepens slightly and moves into southern
SK. Low will drag a cold front through the CWA this 
afternoon/evening. Gusty southerly winds expected ahead of it and 
west/northwest winds behind it. Wind will flirt with advisory 
criteria over northwest SD late this afternoon/early this evening.
1KJ/kg MLCAPE will develop along cold front with modest MLCIN. 
0-6km bulk shear around 50kts will support isolated strong/severe 
storms during peak heating when cap should break along cold front.
Most likely location for severe storms should be along/east of a 
line from Philip to Martin from 22z-04z per CAMS. A few SHRA/TS 
expected tonight as main synoptic energy moves through. 
Temperatures will be near guidance with highs this afternoon in 
the 80s east of the Black Hills.

Sunday, upper trough over northwest CONUS will be productive as it 
spits out another wave bringing additional chances for SHRA/TS. 
Surface-based convection may be difficult to come by given forecast 
soundings, but 500J/kg MUCAPE portends embedded storms. Temperatures 
will near guidance.

Next week, blocking upper ridge from TX to the Great Lakes 
combined with mean upper trough over the western CONUS will bring 
southwest flow aloft into the northern plains. A series of 
shortwaves will bring a daily chance of convection with the main 
wave potentially coming out Thursday. Low confidence in timing. 
Subjectively, it is a good pattern for potentially active storms, 
but moisture return may be limited. Temperatures will pleasantly 
mild with highs 5-10F above normal on average. 

&&

.AVIATION...(For the 06Z TAFS Through 06Z Saturday Night)
Issued At 1045 PM MDT Fri May 6 2022

Mostly VFR conditions are expected through the forecast period.
Isolated to scattered showers/storms are expected in the forecast
area Saturday afternoon and locations may see intermittent MVFR 
conditions.

&&

.FIRE WEATHER...
Issued At 204 AM MDT Sat May 7 2022

Ahead of a cold front, southwesterly winds gusting to 30-45 mph 
will create elevated fire weather conditions today, especially 
over northeastern Wyoming and far southwestern South Dakota where 
the minimum relative humidity will fall to the upper teens this
afternoon. A few thunderstorms are also possible later this 
afternoon/tonight.

&&

.UNR WATCHES/WARNINGS/ADVISORIES...
SD...None.
WY...None.
&&

$$

DISCUSSION...Helgeson
AVIATION...Dye
FIRE WEATHER...Helgeson