000
FXUS63 KUNR 062115
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
215 PM MST THU MAR 6 2014

.SHORT TERM...THIS EVENING THROUGH FRIDAY NIGHT
ISSUED AT 205 PM MST THU MAR 6 2014

PAC NW UPPER TROUGH IS PROGRESSING EAST WITH A SMALLER
SCALE LEAD MID LEVEL IMPULSE ADVECTING EAST OVER SE SK/WESTERN MB.
THE LEAD SYSTEM IS IN THE PROCESS OF SUPPORTING A SFC COLD FRONT
ACROSS THE NORTHERN PLAINS...WITH SFC LOW PRESSURE OVER SE MT AS OF
20Z. THIS SYSTEM WILL PROGRESS QUICKLY EAST THIS EVENING WITH THE PAC
NW UPPER TROUGH ADVECTING SE INTO THE CENTRAL ROCKIES. PRECIP CHANCES
WILL INCREASE ACROSS THE SW HALF OF THE FA AS THIS SECONDARY WAVE
ADVANCES EAST WITH A LL FGEN/CONVERGENCE RESPONSE NOTED IN MODEL
PROGS. GIVEN AVAILABLE LL MOISTURE IN UPSTREAM RAOBS/LSA NOTED IN
Q-VECTOR PROGS/AND LL CONVERGENCE PER WEAK FGEN RESPONSE...HAVE
RAISED POPS OVER THE FAR WEST TO HIGH CHANCE/LOW LIKELY...MAINLY WY
COUNTIES TONIGHT...WITH ONLY A SLIGHT CHANCE MENTION OVER THE
REMAINDER OF THE AREA. MAJORITY OF FORCING WILL SHIFT QUICKLY SE OUT
OF THE FA /EVEN QUICKER IN THE 18Z NAM GUIDANCE/...WITH SOME LOW
TRANSITION POPS FOR FRI MORNING. EASTERLY UPSLOPE FLOW OVER THE
EASTERN BH WITH SUFFICIENT LL MOISTURE WILL SUPPORT STRATUS OVER THE
EASTERN BH FOOTHILLS WITH THE POTENTIAL FOR DRIZZLE/FREEZING DRIZZLE
EARLY FRIDAY MORNING...MAINLY BEFORE DIURNAL HEATING SUPPORTS SOME
BL DEEPENING. BUFFER PROGS SUGGEST STEEP LL LAPSE RATES OVER THE BH
FRI WHERE MOST LOCATIONS WILL BE ABOVE THE SHALLOW FRONTAL
INVERISON. IN ADDITION...NAM BEST LI/S ARE PROGGED NEAR 0 MOST OF
FRIDAY...SUGGESTING A CONVECTIVE POTENTIAL IF ENOUGH INSOLATION
DEVELOPS AS EVIDENT IN BUFFER PROGS. NORTHERLY FLOW WILL ALSO
SUPPORT SOUTHERN BH EDDY FORMATION WITH SUFFICIENT RESIDUAL MOISTURE
IN PLACE TO HELP SUPPORT POSSIBLE SHALLOW CONVECTION OVER THE SBH.
HAVE RETAINED A 30-40 POP MENTION OVER THE BH WITH SLIGHTLY HIGHER
NUMBERS OVER THE SBH WHERE ENHANCED CONVERGENCE IS EXPECTED...WITH
50S THERE. RETAINED SOME LOW POPS OVER THE BH FRI EVENING...MAINLY
FOR ANY LINGERING DIURNAL CONVECTION.

AS FOR TEMPS...SFC COLD FRONT WILL BUILD SOUTH ACROSS THE FA
TONIGHT...WITH THE FRONTAL INVERISON GROWING ACROSS THE SD PLAINS
AND PART OF THE NE WY PLAINS. TEMPS WILL FALL THROUGH TONIGHT...WITH
HIGHS WILL EXPECTED TO BE REACHED ACROSS MOST OF THE SD PLAINS
FRIDAY MORNING. NE WY TEMPS /ESP ACROSS NORTHERN AREAS/ WILL BE
TRICKY AS DIURNAL MIXING AND HIGH TERRAIN INFLUENCES SHOULD BREAK
THE SHALLOW FRONTAL INVERSION. CLOUDS AND ONGOING CAA ON THE SD
PLAINS WILL MAKE FOR A TRICKY FORECAST WITH MOST PLACES NOT SEEING
TEMPS RECOVERING A WHOLE LOT...IF AT ALL. IT WILL ALL DEPEND ON THE
DEGREE OF CLOUD COVER. THE RAPID CITY AREA AND ADJACENT PLAINS WILL
HAVE THE MOST DIFFICULT TIME WITH UPSLOPE EASTERLY NEAR SATURATED
FLOW.

&&

.LONG TERM...SATURDAY THROUGH THURSDAY
ISSUED AT 205 PM MST THU MAR 6 2014

UPPER RIDGE DEVELOPS OVER THE REGION THIS WEEKEND WITH
DRY AND MILD WEATHER...ESPECIALLY ON SUNDAY WHEN HIGHS WILL LIKELY
REACH INTO THE 60S ACROSS PORTIONS OF NORTHEASTERN WY AND
SOUTHWESTERN SD. CHANCES FOR PCPN WILL RETURN LATE MONDAY INTO THE
MIDDLE OF NEXT WEEK AS RIDGE WEAKENS AND ACTIVE NORTHWEST FLOW ALOFT
DEVELOPS. TEMPERATURES WILL BE ABOVE AVERAGE FROM SATURDAY THROUGH
MONDAY...WITH TEMPERATURES CLOSER TO SEASONAL AVERAGES FOR THE
MIDDLE OF NEXT WEEK.

&&

.AVIATION...FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING
ISSUED AT 205 PM MST THU MAR 6 2014

VFR CONDITIONS WILL CONTINUE ACROSS THE AREA THROUGH THE
AFTERNOON. A COLD FRONT WILL MOVE THROUGH THE FORECAST AREA LATE
THIS AFTERNOON AND EVENING...SWITCHING WINDS TO A NORTHWESTERLY
DIRECTION. RAIN SHOWERS WILL DEVELOP BY EARLY EVENING...MAINLY
ACROSS NORTHEASTERN WY AND SOUTHWESTERN SD...WITH A CHANGEOVER TO
SNOW SHOWERS OVERNIGHT. MVFR/IFR CONDITIONS CAN BE EXPECTED ACROSS
MUCH OF NORTHEASTERN WY AND WESTERN SD LATER TONIGHT INTO FRIDAY.

&&

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

$$

SHORT TERM...JC
LONG TERM...26
AVIATION...26