000
FXUS63 KUNR 141804
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
1204 PM MDT TUE MAY 14 2013

.SHORT TERM...TODAY THROUGH WEDNESDAY NIGHT
ISSUED AT 248 AM MDT TUE MAY 14 2013

LATEST SFC ANALYSIS SHOWS A COLD FRONT EXTENDING FROM NORTH CENTRAL
NORTH DAKOTA INTO FAR NORTHWESTERN SOUTH DAKOTA AND FAR
NORTHEASTERN WYOMING. A TIGHT SFC PRESSURE GRADIENT AND GUSTY
NORTHWEST WINDS EXIST BEHIND THE FRONT. LATEST MSAS ANALYSIS SHOWS
PRESSURE RISES AROUND 4MB/3HR BEHIND THE FRONT OVER SOUTHEASTERN
MONTANA. THE COLD FRONT IS EXPECTED TO PASS THROUGH THE FORECAST
AREA BY MIDDAY TODAY. SO FAR IT LOOKS LIKE THE STRONGEST WINDS
WILL OCCUR FOR A BRIEF PERIOD IMMEDIATELY AFTER THE FRONTAL
PASSAGE...BUT VERY WINDY CONDITIONS WILL CONTINUE THROUGH THE
AFTERNOON. THE WINDIEST CONDITIONS WILL BE LOCATED ON THE PLAINS
OF NORTHWESTERN AND WEST CENTRAL SOUTH DAKOTA...SO HAVE ISSUED A
WIND ADVISORY FOR THOSE AREAS TODAY INTO THE EARLY EVENING. HIGH
TEMPERATURES ARE A CHALLENGE TODAY DUE TO THE ALREADY MILD
OVERNIGHT LOWS AND COLD ADVECTION BEHIND THE FRONT TODAY. IT LOOKS
LIKE HIGH TEMPERATURES WILL REACH THE MID 70S IN NORTHWESTERN
SOUTH DAKOTA AND FAR NORTHEASTERN WYOMING WITH UPPER 80S OVER
SOUTH CENTRAL SOUTH DAKOTA.

THE WIND WILL DIMINISH DURING THE EARLY EVENING HOURS AS HIGH
PRESSURE BUILDS INTO THE AREA. NAM CONTINUES TO SHOW MID LEVEL
INSTABILITY DEVELOPING OVER SOUTHWESTERN AND SOUTH CENTRAL SOUTH
DAKOTA LATE TONIGHT SO HAVE INCLUDED LOW POPS. WITH DRY AIR IN THE
LOWER LEVELS MAY ONLY SEE SOME SPRINKLES REACH THE GROUND WITH AN
ISOLATED LIGHTNING STRIKE OR TWO.

THE HIGH PRESSURE SYSTEM WILL MOVE OFF TO THE EAST ON WEDNESDAY
AND SOUTHERLY WINDS WILL PUSH TEMPERATURES BACK INTO THE 70S ON
THE PLAINS.

&&

.LONG TERM...THURSDAY THROUGH MONDAY
ISSUED AT 248 AM MDT TUE MAY 14 2013

UPPER RIDGE SHIFTS EAST LATE IN THE WEEK AS DEEP UPPER TROF SLOWLY
ENTERS THE WESTERN CONUS. CHANCES FOR SHOWERS/STORMS WILL BE ON THE
INCREASE FRIDAY INTO THE WEEKEND AS THE LARGE UPPER TROF CROSSES THE
ROCKIES. ABOVE AVERAGE TEMPERATURES WILL PERSIST INTO FRIDAY...THEN
FALL BELOW AVERAGE OVER THE WEEKEND AS UPPER TROF CROSSES THE AREA.

&&

.AVIATION...FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON
ISSUED AT 1202 PM MDT TUE MAY 14 2013

VFR CONDITIONS WILL PREVAIL THROUGH THURSDAY MORN. GUSTY NORTHWEST
WINDS WILL CONTINUE OVER THE SOUTH DAKOTA PLAINS THROUGH MUCH OF
THIS AFTERNOON BEFORE DIMINISHING BY THIS EVENING.

&&
.FIRE WEATHER...
ISSUED AT 248 AM MDT TUE MAY 14 2013

GUSTY NORTHWEST WINDS WILL OCCUR ACROSS WESTERN SOUTH DAKOTA TODAY
BEHIND A COLD FRONT CROSSING THE AREA THIS MORNING. DEWPOINTS AND
RELATIVE HUMIDITY WILL INCREASE IMMEDIATELY BEHIND THE FRONT THIS
MORNING...BUT THEN VERY DRY AIR WILL FLOW INTO THE AREA THIS
AFTERNOON. DUE TO THE LOW RH THIS AFTERNOON AND THE GUSTY
NORTHWEST WINDS...ALONG WITH THE DRY CONDITIONS HAVE ISSUED A RED
FLAG WARNING FOR THE NORTHWESTERN SOUTH DAKOTA FIRE ZONES
SDZ261 AND 266. CONDITIONS WILL IMPROVE DURING THE EARLY EVENING.

&&

.UNR WATCHES/WARNINGS/ADVISORIES...
SD...WIND ADVISORY UNTIL 7 PM MDT THIS EVENING FOR SDZ001-002-012>014-
     026-031-032-043-072-073.

     RED FLAG WARNING UNTIL 7 PM MDT THIS EVENING FOR SDZ261-266.

WY...NONE.
&&

$$

SHORT TERM...10
LONG TERM...15
AVIATION...77
FIRE WEATHER...10