Area Forecast Discussion
Issued by NWS Rapid City, SD

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44

FXUS63 KUNR 170519

Area Forecast Discussion For Western SD and Northeastern WY
National Weather Service Rapid City SD
1119 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 06Z TAFS Through 06Z Friday Night)
Issued At 1118 PM MDT Thu Mar 16 2017

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


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.




SHORT TERM...Helgeson
LONG TERM...Helgeson
FIRE WEATHER...Helgeson is the U.S. government's official web portal to all federal, state and local government web resources and services.