Area Forecast Discussion
Issued by NWS Rapid City, SD

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
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 45 46 47 48 49 50
000
FXUS63 KUNR 021650
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
1050 AM MDT WED SEP 2 2015

.SHORT TERM...TODAY THROUGH THURSDAY NIGHT
ISSUED AT 248 AM MDT WED SEP 2 2015

08Z SFC ANALYSIS SHOWS WEAK LOW PRESSURE CENTERED OVER CENTRAL
SOUTH DAKOTA WITH A DEEPENING TROUGH EXTENDING FROM NW MT INTO
NERN WY. AN AREA OF MID-HIGH CLOUDS IS NOTED OVER NORTHEASTERN
WYOMING...ASSOCIATED WITH A WEAK SHORTWAVE.

THE SURFACE TROUGH IN WYOMING WILL SHIFT SLIGHTLY EASTWARD TODAY
WITH WESTERLY DOWNSLOPE WINDS CREATING VERY HOT AND DRY CONDITIONS
THIS AFTN ESPECIALLY OVER NORTHEASTERN WYOMING. THE WEAK UPPER SHORTWAVE
WILL CONTINUE EASTWARD ACROSS THE FORECAST AREA TODAY. LATEST NAM
RUN SHOWS DIURNAL HEATING OVERCOMING THE CAPPING INVERSION OVER
PARTS OF WESTERN AND CENTRAL SOUTH DAKOTA LATE THIS AFTN...HOWEVER
VERY LITTLE MOISTURE IS AVAILABLE SO EXPECT ONLY A BRIEF INCREASE
IN CLOUDS AS THE SHORTWAVE MOVES EASTWARD ACROSS THE AREA TODAY.
DRY WEATHER WILL CONTINUE OVERNIGHT TONIGHT AND ON THURSDAY.
DEWPOINTS AND RH ARE EXPECTED TO BE SLIGHTLY HIGHER ON THURSDAY
AFTN...ESP OVER CENTRAL SOUTH DAKOTA AS SRLY SFC WINDS MAY BE ABLE
TO PUSH INCREASED LL MOISTURE INTO THE REGION. THERE MAY BE ENOUGH
MOISTURE AND INSTABILITY FOR A SLIGHT CHANCE OF THUNDERSTORMS OVER
PARTS OF SWRN AND SC SD ON THURSDAY AFTN WITH A BETTER CHANCE OF
THUNDERSTORMS OVER WESTERN AND CENTRAL SD ON THURSDAY NIGHT AS A
STRONGER SHORTWAVE INCREASES MID AND HIGH LEVEL MOISTURE ACROSS
THE REGION.

.LONG TERM...FRIDAY THROUGH TUESDAY
ISSUED AT 248 AM MDT WED SEP 2 2015

MODELS ARE HAVING A SOMEWHAT DIFFICULT TIME FIGURING
OUT THE TIMING AND TRACK OF THE PAC NW UPPER WAVE. STRONG UPPER LOW
WILL CROSS THE PAC NW FRIDAY...THEN NEVADA TO THE NRN ROCKIES SAT.
UPPER LOW/TROUGH WILL GO NEG TILT SUN OVER ERN MT/WRN ND. CHANCES
FOR CONVECTION WILL INCREASE LATER FRI THROUGH SAT NIGHT ACROSS THE
NRN PLAINS AS BROAD FORCING DEVELOPS ACROSS THE REGION. A COLD FRONT
IS THE PROGGED TO CROSS THE AREA SUNDAY AS COOLER AND DRIER AIR
FILTER IN BEHIND THE LOW WHICH WILL EVENTUALLY PUSH INTO ND/CANADA
SUN NIGHT. CHANCES FOR PRECIP WILL QUICKLY END SUNDAY...WITH BELOW
AVG TEMPS EXPECTED EARLY NEXT WEEK. COOLER AND DRIER AIR IS THEN
EXPECTED FOR THE FIRST HALF OF NEXT WEEK.

&&

.AVIATION...FOR THE 18Z TAFS THROUGH 18Z THURSDAY
ISSUED AT 1049 AM MDT WED SEP 2 2015

VFR CONDITIONS EXPECTED THROUGH THE PERIOD.

&&

.FIRE WEATHER...
ISSUED AT 248 AM MDT WED SEP 2 2015
VERY DRY AND BREEZY CONDITIONS WILL DEVELOP ACROSS PARTS OF NERN
WYOMING TODAY. HIGH TEMPERATURES WILL BE IN THE 90S WITH MINIMUM
RELATIVE HUMIDITY FALLING TO 8 TO 15 PERCENT. SOUTHWEST WINDS WILL
BECOME BREEZY TO WINDY OVER SRN CAMPBELL COUNTY SO WILL KEEP THE
RED FLAG WARNING IN EFFECT FOR SOUTHERN CAMPBELL COUNTY TODAY INTO
THIS EVENING.

&&

.UNR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
WY...RED FLAG WARNING UNTIL 7 PM MDT THIS EVENING FOR WYZ259.

&&

$$

SHORT TERM...10
LONG TERM...13
AVIATION...POJORLIE
FIRE WEATHER...10



USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.