117 
FXUS63 KUNR 162309
AFDUNR

Area Forecast Discussion For Western SD and Northeastern WY
National Weather Service Rapid City SD
509 PM MDT Thu Mar 16 2017

.SHORT TERM...(This Evening Through Friday Night)
Issued at 211 PM MDT Thu Mar 16 2017

20z surface analysis had low near KICR with trough into central 
WY and cold front into southwest SD into northeast WY. Shortwave 
noted on water vapour across eastern MT into central WY. Post 
frontal virga and perhaps a light -SHRA indicated on regional 
radar loop under steep 850-700mb lapse rate regime. Activity will
shift east this evening with isolated to scattered PoPs 
warranted. Gusty winds will subside this evening as boundary layer
decouples and pressure rise bubble heads south of CWA. Temperatures
tonight will be near guidance as surface high slides into the CWA.

Friday, much cooler day expected. Upper ridge will build over the 
Rockies and head toward the CWA Friday night. Surface high shifts 
east with return flow starting in earnest Friday night.

.LONG TERM...(Saturday Through Thursday)
Issued at 211 PM MDT Thu Mar 16 2017

Strong upper and thermal ridge expected Saturday with highs 
15-30F above normal in the southwest and 5-15F above normal in the
northeast given downslope flow and deeply mixed boundary layer.

Sunday, fast moving shortwave trough moves across the US/Canadian 
border dragging a cold front through the CWA. Latest guidance 
suggests front arrival quicker, so have lowered temperatures in 
the far northwest to account. Few showers possible with the main 
forcing late Sunday afternoon and evening.

Monday through Wednesday, fairly progressive fast flow expected with 
transient shortwaves and fronts resulting in PoPs with each feature.

Thursday, most guidance shows an upper low over the central of 
southern plains heading northeast into the Midwest. Even though 
models are fairly consistent, amount of cold air wrapping into 
system questionable and thus precipitation type will remain up in 
the air.

&&

.AVIATION...(For the 00Z TAFS Through 00Z Friday Evening)
Issued At 507 PM MDT Thu Mar 16 2017

Isolated showers will end this evening. Local MVFR visibility is
possible with the showers. Otherwise VFR conditions expected 
through Friday afternoon.

&&

.FIRE WEATHER...
Issued At 211 PM MDT Thu Mar 16 2017

Warm and dry westerly flow will support near critical fire 
weather conditions once again Saturday, especially over northeast 
WY and southwest SD. Fire weather headlines may be needed if the 
gusty winds and deep mixing materialize.

&&

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

$$

SHORT TERM...Helgeson
LONG TERM...Helgeson
AVIATION...7
FIRE WEATHER...Helgeson