Area Forecast Discussion
Issued by NWS Rapid City, SD

Home | Current Version | Previous Version | Graphics & Text | 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 45 46 47 48 49 50

000
FXUS63 KUNR 290036 CCA
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
518 PM MDT MON JUL 28 2014

.SHORT TERM...THIS EVENING THROUGH TUESDAY NIGHT
ISSUED AT 207 PM MDT MON JUL 28 2014

PERSISTENT WESTERN NOAM RIDGE WILL REMAIN IN PLACE WITH THE
NORTHERN PLAINS BEING EAST OF THE RIDGE AXIS. LONG FETCH SOUTHERLY
FLOW ON THE WEST SIDE OF THE RIDGE WILL CONTINUE TO SUPPORT
MONSOON FLOW WITH MID-HIGH LEVEL MOISTURE AND EMBEDDED IMPULSES
ROTATING AROUND THE RIDGE PERIPHERY. ONCE SUCH IMPULSE WILL ADVECT
THROUGH THE SW FA THROUGH TUESDAY...POSSIBLY SUPPORTING ISOLD
SHRA/TS THERE. OTHERWISE REFLECTED LL FLOW WILL PUSH A SFC TROUGH
THROUGH THE AREA TUES...WITH WINDS BACKING NORTHERLY...REINFORCING
COOLER-DRIER FLOW INTO THE AREA. RAIN CHANCES LOOK PRETTY
DISMAL...ESP GIVEN LATEST MODEL TRENDS WHICH SUPPORT AN IMPULSE
TRACK MORE SW OF THE FA...BREAKING DOWN THE LL THETA-E BUBBLE OVER
THE WESTERN FA FASTER.

TONIGHT...LL THETA-E RIDGE FROM NE WY THROUGH SCNTRL SD WILL REMAIN
IN PLACE UNDER STEEP MID LEVEL LAPSE RATES. WEAK UVM ASSOCIATED WITH
THE IMPULSE MAY SUPPORT ISOLD SHRA/TS ACTIVITY WITH AN EXPECTED
ACCAS PLUME...WHICH MAY BE ENHANCED BY THE DEPARTING BACKSIDE JET
STREAK FROM THE GREAT LAKES UPPER TROUGH. RETAINED LOW POPS SW
THIRD FOR THIS.

TUESDAY...UPPER IMPULSE WILL TURN SOUTH AWAY FROM THE REGION WITH
LINGERING LSA AND UVM POSSIBLY SUPPORTING A FEW SHRA OVER THE FAR
SW. MODEL TRENDS HAVE BEEN DRIER FOR MUCH OF THE FA GIVEN FURTHER SW
IMPULSE TRACK AND ASSOCIATED STRONGER NORTHERLY DRY PUSH. HAVE
SHAVED POPS BACK. LINGERING LL MOISTURE WITH SW BLACK HILLS LOCAL
CONVERGENCE PER FLOW MAY BE ENOUGH TO SUPPORT A FEW DIURNAL SHOWERS
THERE. OTHERWISE...CHANCES FOR SHRA WILL DIMINISH AND SHIFT SW
THROUGH THE AFTERNOON AS LARGE SCALE SUBSIDENCE SPREADS OVER THE
REGION. HAVE ADJUSTED TEMPS DOWN SOME MOST PLACES...ESP THE FAR SW
WHERE CLOUDS WILL LINGER WITH POSSIBLE SHRA. A FAST MOVING IMPULSE
ROTATING AROUND THE EASTERN EDGE OF THE EASTERN NOAM UPPER TROUGH
WILL ADVANCE SOUTH THROUGH THE CENTRAL DAKOTAS TUE
NIGHT...SUPPORTING A WEAK SFC LOW INTO THE EASTERN FA. THE NAM
DID INDICATE SOME POTENTIAL SHRA ACTIVITY WITH THIS FEATURE...BUT
REMAINS THE WET OUTLIER. LEFT THINGS DRY FOR NOW UNTIL A BETTER
HANDLE ON THE TRACK/TIMING/AND STRENGTH OF THIS FEATURE IS
ESTABLISHED.

&&

.LONG TERM...WEDNESDAY THROUGH MONDAY
ISSUED AT 207 PM MDT MON JUL 28 2014

THE PERSISTENT RIDGE OVER THE WESTERN UNITED STATES REMAINS IN PLACE
THROUGH THE EXTENDED PERIOD. COOL NORTHWEST UPPER FLOW WILL CONTINUE
TO BRING SLIGHTLY BELOW AVERAGE TEMPERATURES TO THE NORTHERN HIGH
PLAINS. A VERY SUBTLE WARMING TREND IS EXPECTED BY THE WEEKEND...BUT
OVERALL TEMPERATURES WILL CONTINUE TO BE SLIGHTLY BELOW AVERAGE TO
NEAR AVERAGE. WITH ABUNDANT SUNSHINE EXPECTED AND SOUTHEASTERLY
FLOW...DIURNAL HEATING MAY LEAD TO A CHANCE OF THUNDERSTORMS ACROSS
THE HIGHER TERRAIN OF THE BLACK HILLS DURING THE PERIOD. HOWEVER
WITH WEAK FLOW AND LIMITED MOISTURE IN PLACE...ONLY EXPECT A FEW
ISOLATED SHOWERS/STORMS OVERALL.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 517 PM MDT MON JUL 28 2014

VFR CONDITIONS ARE EXPECTED THROUGH THE FORECAST PERIOD. ISOLATED
-TSRA MAY OCCUR OVER SOUTHWEST SOUTH DAKOTA AND NORTHEAST WYOMING.

&&

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

$$

SHORT TERM...JC
LONG TERM...MLS
AVIATION...HELGESON








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