000
FXUS63 KUNR 051621
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
1021 AM MDT SUN JUL 5 2009

.DISCUSSION...16Z SFC ANALYSIS SHOWS WEAK HIGH PRESSURE OVER THE
DAKOTAS AND NEBRASKA WITH WEAK LOW PRESSURE OVER
MONTANA...WYOMING AND COLORADO. 12Z MODELS CONTINUE TO SHOW
CAP REMAINS IN PLACE OVER MOST OF WESTERN SOUTH DAKOTA...SO HAVE
PUSHED THE THUNDERSTORM CHANCE FARTHER BACK TO THE WEST...COVERING
MAINLY NORTHEASTERN WYOMING AND THE BLACK HILLS. HOWEVER...IT
LOOKS THE MODELS ARE ALSO UNDERESTIMATING THE AMOUNT OF LOW LEVEL
MOISTURE...WITH MODEL DEWPOINTS A FEW DEGREES LOWER THAN INDICATED
BY THE LATEST SFC OBSERVATIONS. THAT DIFFERENCE MAY BE ENOUGH TO
BREAK THE CAPPING INVERSION OVER FAR WESTERN SOUTH DAKOTA AND
ALLOW A FEW THUNDERSTORMS TO DEVELOP OVER THAT AREA LATE THIS
AFTERNOON OR EARLY EVENING.

&&

.AVIATION...ISOLATED THUNDERSTORMS WILL BE POSSIBLE THIS
AFTERNOON AND EVENING ACROSS NORTHEASTERN WYOMING AND THE BLACK HILLS
VICINITY. LOCALIZED AREAS OF MVFR CONDITIONS WILL BE POSSIBLE NEAR
THESE STORMS. OTHERWISE VFR CONDITIONS EXPECTED THROUGH MONDAY
MORNING.


&&

.PREV DISCUSSION... /ISSUED 222 AM MDT SUN JUL 5 2009/

DISCUSSION...08Z SURFACE ANALYSIS HAD BOUNDARY FROM CENTRAL MT
INTO EASTERN CO. SHORTWAVE ENERGY NOTED OVER EASTERN MT AND PARTS
OF UT. ACTIVITY FROM THESE WAVES SHOULD PASS THE CWA TO THE NORTH
AND SOUTH THIS MORNING. MAIN WAVE OF NOTE IS PV WIGGLE ENTERING
CA. THIS ENERGY WILL QUICKLY MOVE INTO CO BY 12Z MONDAY. THIS
SHOULD BE THE MAIN FOCUS FOR CONVECTION TODAY...MAINLY SOUTH OF
CWA. BUT 750J/KG CAPE AND MINIMAL CAP WILL SET STAGE FOR LOW POP -TSRA
THIS AFTERNOON/EVENING...ESPECIALLY OVER THE HIGHER TERRAIN. SHEAR
WILL BE MARGINAL. HIGHS TODAY NEAR TO SLIGHTLY BELOW GUIDANCE
GIVEN ANTECEDENT MOIST CONDITIONS.

MONDAY/TUESDAY...UPPER RIDGE BUILDS INTO THE NORTHERN PLAINS.
THERMAL RIDGE BUILDS MONDAY AND PEAKS TUESDAY MORNING. ATMOSPHERE
SHOULD REMAIN CAPPED MONDAY...BUT ENOUGH ENERGY MAY TOP TO THE
RIDGE TO PRODUCE TSRA TUESDAY AFTERNOON/NIGHT AS WEAK LOW AND
FRONT MOVES THROUGH THE CWA. WILL BE BATTLING SUBSTANTIAL CAP...BUT
CAPE VALUES FROM 2-3KJ/KG NOTED OVER CENTRAL SD DURING PEAK
HEATING TUESDAY. HIGHS MONDAY ABOVE 90F IN MANY LOCATIONS. HIGHS
TUESDAY TRICKY GIVEN POSITION OF FRONT...BUT LIKELY ABOVE 90F OVER
THE SOUTHEAST AND IN THE 80S TO THE NORTHWEST.

EXTENDED...AN UPPER RIDGE WILL SET UP ACROSS THE SOUTHWESTERN U.S.
DURING THE SECOND HALF OF THE COMING WORK WEEK. A BIG PACIFIC TROUGH
WILL ALSO SET UP ON THE NORTHWEST COAST AND SPIN OFF SEVERAL WEATHER
SYSTEMS ACROSS THE NORTHERN ROCKIES AND NORTHERN PLAINS.  THE
STRONGEST OF THESE IS FORECAST TO CROSS THE DAKOTAS WEDNESDAY NIGHT
AND EARLY THURSDAY. TEMPERATURES ARE FORECAST TO BE ABOVE AVERAGE.


&&

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

$$

000
FXUS65 KCYS 050941
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
341 AM MDT SUN JUL 5 2009

.SHORT TERM...TODAY THROUGH MONDAY NIGHT...
WIDELY SCATTERED SHOWERS CONTINUE EARLY THIS MORNING OVER SOUTH
CENTRAL WYOMING.  THE ACTIVITY IS MOVING SOUTHEAST AND WEAKENING
AHEAD OF A SHORTWAVE TROUGH.  MODELS...ESPECIALLY THE NAM HAS BEEN
DEVELOPING QPF OVER THE ENTIRE SOUTHERN PART OF THE CWA THROUGH 15Z.
THE OTHER CONCERN THROUGH MID MORNING WILL BE FOG.  THE BOUNDARY
LAYER IS NEARLY SATURATED AT 09Z WITH FOG ALREADY OBSERVED AT KCYS
AND KLAR.  EXPECT THE FOG AND LOW CLOUDS TO DEVELOP OVER MUCH OF THE
REST OF THE CWA BY SUNRISE AND THEN CONTINUE UNTIL 15Z.  ANOTHER
ROUND OF AFTERNOON AND EVENING THUNDERSTORMS IS ON TAP FOR MUCH OF
THE CWA LATER TODAY.  THE ATMOSPHERE WILL BE MOIST AND UNSTABLE
ESPECIALLY TO THE EAST OF THE LARAMIE RANGE.  ANOTHER SHORTWAVE
TROUGH WAS MOVING INTO SOUTHWEST WYOMING AND EASTERN UTAH EARLY THIS
MORNING FROM SATELLITE IMAGERY.  THAT FEATURE MAY MOVE EAST OF THE
CWA BY EARLY AFTERNOON.  HOWEVER...MODELS INDICATE VORTICITY MOVING
INTO THE CWA AT 250 MB BY 00Z AND WAS NEAR THE OREGON AND NORTHERN
CALIFORNIA COAST AT 06Z.  IN ADDITION...SURFACE CONVERGENCE ALONG
THE MOUNTAINS...ESPECIALLY THE LARAMIE RANGE...SHOULD AID IN THE
STORM INITIATION.  THERE WILL ALSO BE BETTER 0-6KM SHEAR OVER THE
CWA LATER TODAY AND SHOULD ENABLE STORMS TO BE STRONGER THAN THOSE
OF SATURDAY.  FREEZING LEVEL WILL STILL BE HIGH AND MAY HINDER LARGE
HAIL DEVELOPMENT.  HAVE INCREASED POPS OVER THE CWA THIS AFTERNOON
AND EVENING AND ADDED THE MENTION OF POSSIBLE SEVERE STORMS EAST OF
THE LARAMIE RANGE AND MAINLY IN WYOMING.  THE LOW CLOUD COVER WILL
HINDER SURFACE HEATING TODAY WITH HIGHS REACHED LATE IN MANY PLACES
AND MAY PRODUCE MAXIMUM TEMPERATURES A BIT COOLER THAN EARLIER
THOUGHT.  HEIGHT ALOFT THEN CONTINUE TO RISE THROUGH 12Z TUESDAY
AND WITH THE ATMOSPHERE SLOWLY DRYING FROM WEST TO EAST.  LATE DAY
THUNDERSTORMS WILL AGAIN BE SCATTERED OVER AREAS ALONG AND EAST OF
THE LARAMIE RANGE ON MONDAY.  STRONGER STORMS WILL BE POSSIBLE OVER
THE PANHANDLE WHERE THERE WILL BE MORE LOW LEVEL MOISTURE PRESENT.
MONDAY WILL ALSO BE WARMER OVER THE CWA.  DRIER AIR SPREAD OVER THE
ENTIRE CWA IN ERNEST MONDAY NIGHT WITH PRECIPITABLE WATER VALUES
DOWN TO ABOUT ONE HALF INCH BY 12Z TUESDAY.

.LONG TERM...TUESDAY THROUGH SATURDAY
DRY CONDITIONS WILL PREVAIL OVER THE CWA TUES AND WED.  AN UPPER
RIDGE WILL MOVE ACROSS THE FORECAST AREA TUES...WITH DOWNSLOPE WINDS
AT THE SURFACE IN THE DRY AIR MASS.  THE FLOW ALOFT WILL BECOME SW
ON WED AS AN UPPER LOW MOVES FROM THE PAC NW INTO SOUTHERN CANADA.
MID LEVEL MOISTURE WILL INCREASE OVER THE AREA ON THUR WITH WEST
FLOW ALOFT.  A FEW WEAK DISTURBANCES WILL MOVE ACROSS THE CWA AT
THIS TIME.  A WEAK COLD FRONT WILL ALSO MOVE ACROSS THE FORECAST
AREA.  THIS WILL RESULT IN A SLIGHT CHANCE OF AFTERNOON AND EVENING
THUNDERSTORMS...MAINLY EAST OF THE LARAMIE RANGE.  FOR FRI AND
SAT...THE UPPER RIDGE WILL BEGIN TO BUILD OVER THE ROCKIES WITH A
FEW THUNDERSTORMS IN THE MOUNTAINS.  DIURNAL THUNDERSTORMS WILL
OCCUR ACROSS THE AREA ON SAT WITH AMPLE MID LEVEL MOISTURE AND
SURFACE BASED INSTABILITY.  HIGH TEMPERATURES WILL BE FROM 5 TO 10
DEGREES ABOVE NORMAL EACH DAY.

&&

.AVIATION...WIDESPREAD IFR CEILINGS AND VISIBILITIES IN FOG WILL
DEVELOP OVER MUCH OF THE CWA BY SUNRISE AND THEN CONTINUE THROUGH
MID MORNING.  A SCATTERED COVERAGE OF AFTERNOON AND EVENING STORMS
WILL AGAIN AFFECT MUCH OF THE CWA LATER TODAY.  THE STRONGER STORMS
WILL HAVE MVFR CEILINGS AND VISIBILITIES ASSOCIATED.  LOW CEILINGS
AND VISIBILITIES IN FOG ARE AGAIN POSSIBLE LATE TONIGHT THROUGH MID
MORNING MONDAY OVER THE NEBRASKA PANHANDLE.  SOME AFTERNOON AND
EVENING THUNDERSTORMS WILL DEEVLOP AGAIN ON MONDAY...ESPECIALLY OVER
THE NEBRASKA PANHANDLE.

&&

.FIRE WEATHER...WARMER AND DRIER AIR WILL RETURN TO THE CWA STARTING
ON MONDAY AND CONTINUING THROUGH MOST OF THIS WEEK.  MINIMUM RELATIVE
HUMIDITIES WILL BE BETWEEN 10 AND 20 PERCENT ON MANY OF THE
AFTERNOONS...WITH THE LOWEST VALUES TO THE WEST OF THE LARAMIE RANGE.
IN THOSE SAME AREAS...DAYTIME SOUTHWEST WINDS WILL GUST AS HIGH AS
25 TO 30 MPH.  DRYING OF THE FUELS WILL PICK UP THIS WEEK AND FIRE
WEATHER CONCERNS WILL ALSO INCREASE.

&&

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.

&&

$$

WEILAND/KMD

000
FXUS65 KRIW 050911
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
311 AM MDT SUN JUL 5 2009

.SHORT TERM...TODAY THROUGH TUESDAY NIGHT
GENERALLY IMPROVING CONDITIONS NOTED OVER THE CWA THIS MORNING
AFTER AN ACTIVE EVENING. STORMS OVER PORTIONS OF THE CWA WERE
NOTED ON RADAR INTO THE LATE EVENING AND EARLY MORNING HOURS.
SHIELD OF RAIN MOVED OVER NATRONA COUNTY CAUSING SOME CONCERN OVER
ADDITIONAL FLOODING AROUND THE CASPER AREA. RAIN FROM THIS SYSTEM
DID CLIP THE CITY...THOUGH DISSIPATED QUICKLY AFTER MOVING INTO
THE COUNTY.

WITH RAINFALL OVER CENTRAL WYOMING...EXPECTING PATCHY FOG OVER
PORTIONS OF THE WIND RIVER BASIN. SOME AREAS HAVE SEEN SOME FOG
DEVELOPMENT ALREADY...WITH ADDITIONAL ACTIVITY EXPECTED INTO THE
LATE MORNING HOURS. RIDGE OF HIGH PRESSURE WILL BUILD BEGIN TO
MOVE INTO THE AREA TODAY. HOWEVER...ANOTHER SHORTWAVE IS EXPECTED
TO MOVE THROUGH THE STATE TO BRING ISOLATED TO SCATTERED AFTERNOON
SHOWERS AND THUNDERSTORMS. MODELS INDICATE ANOTHER ROUND OF
INSTABILITY OVER THE AREA...WITH THUNDERSTORMS CONTAINING THREATS
OF SMALL HAIL AND GUSTY WIND.

DRIER SOUTHWEST FLOW EXPECTED TO MOVE INTO THE CWA MONDAY
AFTERNOON AS RIDGE GAINS STRENGTH. EVEN AS THIS RIDGE
STRENGTHENS...INCREASED JET DYNAMICS WILL COMBINE WITH LINGERING
MOISTURE TO BRING SOME ISOLATED SHOWERS AND THUNDERSTORMS OVER THE
NORTHERN MOUNTAINS. RIDGE AXIS EXPECTED TO PASS THROUGH THE STATE
BY TUESDAY MORNING WITH DECREASED SHOWER ACTIVITY EXPECTED UNDER
THE SOUTHWEST FLOW.

TEMPERATURES WILL WARM THROUGH MONDAY AS THERMAL RIDGE MOVES OVER
AREA. THIS THERMAL RIDGE WILL ALLOW TEMPERATURES IN THE EASTERN
BASINS TO REACH THE LOW TO MID 90S BY MONDAY AFTERNOON...WITH A
SLIGHT COOLING EXPECTED BY TUESDAY.

.LONG TERM...WEDNESDAY THROUGH SUNDAY
NO MAJOR CHANGES IN OVERALL FORECAST WEDNESDAY THROUGH SUNDAY.  GFS
AND ECMWF IN OVERALL AGREEMENT EJECTING SHORTWAVE FROM CLOSED LOW
OFF THE NORTHWEST COAST...ACROSS NORTHWEST U.S. INTO SOUTH CENTRAL CANADA
WEDNESDAY AND WEDNESDAY NIGHT OVER STRONG UPPER HIGH PRESSURE
CENTERED OVER NEW MEXICO. DRY...HOT AND BREEZY TO WINDY PREFRONTAL
CONDITIONS UNDER 18C H7 THERMAL RIDGE WILL PREVAIL ACROSS SOUTH
AND CENTRAL WYOMING...WITH FAR NORTHERN WYOMING ON THE FRINGE OF
BETTER MOISTURE AND INSTABILITY OVER MONTANA. DRY FRONT TO PUSH
INTO NORTH CENTRAL WYOMING AND DOWN INTERSTATE 25 CORRIDOR
WEDNESDAY NIGHT BEHIND SHORTWAVE. AFTERWARDS...UPPER HIGH CENTERED
OVER NEW MEXICO TO DOMINATE WEATHER PATTER INTO NEXT WEEKEND. ONLY
A SLIGHT CHANCE OF LATE DAY THUNDERSTORMS EXPECTED ACROSS THE FAR
NORTH THURSDAY AND FRIDAY NEAR QUASI-STATIONARY FRONTAL BOUNDARY.
MONSOONAL MOISTURE SHOULD MAKE A RETURN AROUND BACKSIDE OF HIGH BY
NEXT WEEKEND WITH SLIGHT CHANCE POPS TARGETED ACROSS THE SOUTH AND
EAST FOR NOW. GFS MORE AGGRESSIVE WITH MONSOONAL MOISTURE NEXT
WEEKEND THAN ECMWF WITH FORECAST WEIGHTED MORE TOWARD ECMWF IN
LINE WITH AREAS TO OUR SOUTH AND WEST IN WHICH THE MONSOONAL
MOISTURE MUST GET TO FIRST.

&&

.AVIATION...
A SLIGHTLY DRIER AIRMASS OVER THE AREA TODAY WILL RESULT IN OVERALL
LESS THUNDERSTORM COVERAGE AND INTENSITY.  PATCHY MORNING FOG AND
LOW CLOUDS IN AREAS THAT RECEIVED ABUNDANT RAINFALL...PRIMARILY
KRIW-KCPR ROUTES...WILL PARTIALLY OBSCURE TERRAIN THROUGH 15Z.
WIDELY THUNDERSTORMS WILL BEGIN BLOSSOMING OVER THE WEST AND HIGH
TERRAIN AROUND 18Z AND MOVE SOUTHEAST INTO THE CENTRAL BASINS
THROUGH THE AFTERNOON.  THUNDERSTORMS WILL ONCE AGAIN BE MOST
NUMEROUS VCNTY KRIW-KCPR 20Z SUNDAY -04Z MONDAY WHERE LOCAL IFR/MFVR
CONDITIONS WILL BE ENCOUNTERED IN +TSRAGS.  ONLY ISOLATED SHOWERS
WILL LINGER AFTER 06Z MONDAY LEAVING CLEARING SKIES AND PATCHY LOW
CLOUDS AND FOG...PRIMARILY KLND-KRIW-KRIW ROUTES.

&&

.FIRE WEATHER...
WARMING TEMPERATURES AND DECREASED DAYTIME HUMIDITIES ARE EXPECTED
OVER THE NEXT FEW DAYS AS A RIDGE OF HIGH PRESSURE MOVES THROUGH
THE AREA. A FEW DISTURBANCES IN THIS RIDGE WILL ALLOW FOR THE
DEVELOPMENT OF ISOLATED TO SCATTERED SHOWERS AND
THUNDERSTORMS...MAINLY OVER THE NORTHERN MOUNTAINS. SUNDAY WILL
SEE THE POTENTIAL FOR SLIGHTLY MORE WIDESPREAD SHOWERS AND
THUNDERSTORMS...WITH ACTIVITY REACHING EAST OF THE CONTINENTAL
DIVIDE BY THE AFTERNOON HOURS. THUNDERSTORMS MAY CONTAIN SMALL
HAIL AND GUSTY WIND.

&&

.RIW WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SHORT TERM...BRANHAM
LONG TERM...AEM
AVIATION...AEM
FIRE WEATHER...BRANHAM

000
FXUS63 KUNR 050822
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
222 AM MDT SUN JUL 5 2009

.DISCUSSION...08Z SURFACE ANALYSIS HAD BOUNDARY FROM CENTRAL MT
INTO EASTERN CO. SHORTWAVE ENERGY NOTED OVER EASTERN MT AND PARTS
OF UT. ACTIVITY FROM THESE WAVES SHOULD PASS THE CWA TO THE NORTH
AND SOUTH THIS MORNING. MAIN WAVE OF NOTE IS PV WIGGLE ENTERING
CA. THIS ENERGY WILL QUICKLY MOVE INTO CO BY 12Z MONDAY. THIS
SHOULD BE THE MAIN FOCUS FOR CONVECTION TODAY...MAINLY SOUTH OF
CWA. BUT 750J/KG CAPE AND MINIMAL CAP WILL SET STAGE FOR LOW POP -TSRA
THIS AFTERNOON/EVENING...ESPECIALLY OVER THE HIGHER TERRAIN. SHEAR
WILL BE MARGINAL. HIGHS TODAY NEAR TO SLIGHTLY BELOW GUIDANCE
GIVEN ANTECEDENT MOIST CONDITIONS.

MONDAY/TUESDAY...UPPER RIDGE BUILDS INTO THE NORTHERN PLAINS.
THERMAL RIDGE BUILDS MONDAY AND PEAKS TUESDAY MORNING. ATMOSPHERE
SHOULD REMAIN CAPPED MONDAY...BUT ENOUGH ENERGY MAY TOP TO THE
RIDGE TO PRODUCE TSRA TUESDAY AFTERNOON/NIGHT AS WEAK LOW AND
FRONT MOVES THROUGH THE CWA. WILL BE BATTLING SUBSTANTIAL CAP...BUT
CAPE VALUES FROM 2-3KJ/KG NOTED OVER CENTRAL SD DURING PEAK
HEATING TUESDAY. HIGHS MONDAY ABOVE 90F IN MANY LOCATIONS. HIGHS
TUESDAY TRICKY GIVEN POSITION OF FRONT...BUT LIKELY ABOVE 90F OVER
THE SOUTHEAST AND IN THE 80S TO THE NORTHWEST.

EXTENDED...AN UPPER RIDGE WILL SET UP ACROSS THE SOUTHWESTERN U.S.
DURING THE SECOND HALF OF THE COMING WORK WEEK. A BIG PACIFIC TROUGH
WILL ALSO SET UP ON THE NORTHWEST COAST AND SPIN OFF SEVERAL WEATHER
SYSTEMS ACROSS THE NORTHERN ROCKIES AND NORTHERN PLAINS.  THE
STRONGEST OF THESE IS FORECAST TO CROSS THE DAKOTAS WEDNESDAY NIGHT
AND EARLY THURSDAY. TEMPERATURES ARE FORECAST TO BE ABOVE AVERAGE.

&&

.AVIATION...HIGH CLOUDS DOMINATE SKY CONDITIONS IN MOST PARTS OF THE
FORECAST AREA THIS MORNING.  THE PRIMARY EXCEPTION IS KRAP WHERE A
LAYER OF SMOKE FROM A NEARBY FIRE HAS RESULTED IN IFR VSBYS OVER THE
ASOS.  WIDELY SCATTERED THUNDERSTORMS ARE FORECAST TO DEVELOP OVER
NORTHEAST WYOMING AND FAR WESTERN SOUTH DAKOTA THIS AFTERNOON. MVFR
CONDITIONS ARE POSSIBLE IN AND AROUND THE PRECIPITATION. OTHERWISE
VFR CONDITIONS EXPECTED THROUGH SUNDAY MORNING.

&&

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

$$

HELGESON/CARPENTER

000
FXUS65 KRIW 042119
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
319 PM MDT SAT JUL 4 2009

.SHORT TERM...TONIGHT THROUGH TUESDAY

CONVECTION UNDERWAY ACROSS MOST OF THE AREA THIS AFTERNOON. THE
NORTHWEST AND SOUTH ARE SEEING THE MOST ACTIVITY THROUGH 21Z.
EXPECT OTHER AREAS TO FILL IN AS THE DAY GOES INTO THE EVENING.
KEEPING A CLOSE EYE ON NATRONA COUNTY DUE TO RECENT FLOODING ISSUES.
UPPER LEVEL SYSTEM NEARING NW WY AT 21Z AND THIS WILL MOVE ACROSS
THE NORTH TONIGHT. THIS WILL AID IN KEEPING CONVECTION GOING WELL
INTO THE EVENING HOURS IN THE CENTRAL AND EAST. HAVE ADJUSTED
PRECIP CHANCES A LITTLE TONIGHT TO REFLECT THINKING. KEEPING SMALL
HAIL...GUSTY WIND AND HEAVY RAIN IN THE FORECAST THROUGH MIDNIGHT.
SUNDAY WILL SEE CONVECTION FIRE UP AGAIN IN THE AFTERNOON THROUGH
THE EVENING HOURS IN MOST AREAS. THE MODELS CONTINUE TO HINT AT A
WEAK SHORTWAVE IN THE FLOW SUNDAY PM. PRECIPITABLE WATER VALUES ARE
FORECAST FROM ONE HALF TO THREE QUARTERS OF AN INCH OVER THE REGION.
DEWPOINTS IN THE CENTRAL AND EAST SHOULD STILL BE FAIRLY HIGH TO
SUPPORT A FEW STRONG STORMS WITH HAIL AND HEAVY RAIN SUNDAY AFTERNOON
AND EVENING. MONDAY AND TUESDAY WILL SEE LESS CONVECTION AS DRIER
AIR BEGINS TO PUSH INTO THE REGION FROM THE SOUTHWEST. THE UPPER
RIDGE MOVES OVER THE AREA MONDAY AND THEN TO OUR EAST ON TUESDAY
SETTING UP A SW FLOW ALOFT. WILL SEE BREEZY AREAS ON TUE AS WELL.
BEST CHANCE OF STORMS MONDAY LOOKS TO BE OVER THE NORTH AND
NORTHEAST ZONES WITH ISOLATED ACTIVITY ELSEWHERE. ON TUESDAY THE
FAR NORTH AND NORTHEAST ZONES WILL SEE ISOLATED ACTIVITY. TEMPS
WILL BE WARMING UP THROUGH THE SHORT TERM WITH 80S TO AROUND 90 ON
MONDAY THEN 80S AND 90S ON TUESDAY FOR THE LOWER ELEVATIONS.

.LONG TERM...TUESDAY NIGHT THROUGH SATURDAY

ECMWF/GFS AND GEFS MEAN CONTINUE IN GOOD AGREEMENT WITH CLOSED LOW
OFF OF NW COAST EJECTING SEVERAL SHORTWAVES NE INTO CENTRAL CANADA
OVER STRONG RIDGE OVER THE PLAINS. WYOMING WILL MOSTLY REMAIN
UNDER INFLUENCE OF DRY AND WARM SOUTHWEST FLOW WITH SHORTWAVES
PUSHING MOSTLY DRY FRONTS INTO THE NORTH TUESDAY NIGHT AND
WEDNESDAY NIGHT. FORECAST KEEPS LOW POPS NEAR THE FRONT ACROSS
THE FAR NORTH. H7 TEMPERATURES ACROSS THE SOUTH AND CENTRAL FROM
16C-18C...SO BREEZY TO WINDY AND VERY DRY CONDITIONS WILL RESULT
IN TEMPERATURES IN THE MID 80S TO MID 90S ALONG WITH LOW RH/S
MOSTLY IN THE 10-15 PERCENT RANGE. THIS PATTERN WILL DRY OUT FINE
FUELS AND INCREASE THE FIRE DANGER THROUGH THE WEEK. UPPER LOW
OVER THE NORTHWEST TO WEAKEN/FILL FRIDAY AND SATURDAY WITH UPPER
HIGH CENTERED OVER NEW MEXICO STRENGTHENING AND EXPANDING ACROSS
THE ROCKY MOUNTAIN REGION. THIS PATTERN SHOULD BRING BACK THE
RETURN OF MONSOONAL MOISTURE NEXT WEEKEND WITH FORECAST BRINGING
SLIGHT CHANCES OF LATE DAY THUNDERSTORMS OVER THE SOUTHWEST
SATURDAY.

&&

.AVIATION...
MOISTURE TRAPPED BENEATH AN UPPER LEVEL HIGH PRESSURE SYSTEM WILL
REMAIN OVER WYOMING TONIGHT AND SUNDAY. THUNDERSTORMS WITH THE
CAPABILITY OF PRODUCING HEAVY RAIN AND LARGE HAIL WILL CONTINUE
THROUGH AROUND 03Z ACROSS MOST OF THE REGION...BUT COULD CONTINUE
THROUGH 05Z IN NATRONA AND JOHNSON COUNTIES. THESE STORMS WILL
GENERALLY PRODUCE MVFR VISIBILITIES...BUT BRIEF IFR CONDITIONS ARE
POSSIBLE. VFR CONDITIONS AND LIGHT WINDS ARE EXPECTED ACROSS THE
REGION AFTER 08Z...BUT PATCHY DENSE FOG WILL BE POSSIBLE IN THE
VICINITY OF KRIW...KLND AND KCPR FROM 08Z THROUGH 15Z SUNDAY.
SLIGHTLY DRIER...WEST FLOW WILL MOVE ACROSS WYOMING SUNDAY...BUT
ISOLATED SHOWERS AND THUNDERSTORMS WILL SUNDAY AFTERNOON AND EVENING
WITH BRIEF MVFR CONDITIONS POSSIBLE AT TAF SITES.

&&

.FIRE WEATHER...
SCATTERED SHOWERS AND THUNDERSTORMS WILL OCCUR TONIGHT AND AGAIN
SUNDAY AFTERNOON AND EVENING AS THE MOISTURE REMAINS OVER THE REGION.
DRIER AIR WILL BE PUSHING INTO THE SOUTHWEST ZONES MONDAY AND
OVER MUCH OF THE REGION ON TUESDAY. THIS WILL BRING A DECREASE IN
SHOWER AND THUNDERSTORM COVERAGE MONDAY AND TUESDAY. TEMPERATURES
WILL BE MUCH WARMER MONDAY AND TUESDAY WITH LOWER AFTERNOON
RELATIVE HUMIDITY.

&&

.RIW WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

SHORT TERM...AR
LONG TERM...AEM
AVIATION...SMITH
FIRE WEATHER...AR

000
FXUS63 KUNR 042110
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
315 PM MDT SAT JUL 4 2009

.DISCUSSION...21Z SFC ANALYSIS SHOWS HIGH PRESSURE OVER THE WESTERN
DAKOTAS AND EASTERN WYOMING. STRATUS THAT EXISTED OVER SOUTH CENTRAL
SOUTH DAKOTA DURING THE MORNING HAS DEVELOPED INTO CU WITH ISOLATED
SHOWERS. MU CAPE IS AROUND 1000J/KG OVER NORTHEASTERN WYOMING AND
FAR WESTERN SOUTH DAKOTA. A COUPLE OF THUNDERSTORMS DEVELOPED
EARLIER THIS AFTERNOON OVER THE SOUTHERN BLACK HILLS AND HAVE NOW
MOVED SOUTH OF THE FORECAST AREA. SO FAR THE CAP HAS HELD OVER
NORTHEASTERN WYOMING...BUT MAY STILL SEE A FEW THUNDERSTORMS BREAK
THE CAP DURING THE LATE AFTERNOON OR EVENING OVER NORTHEASTERN
WYOMING AND THE BLACK HILLS.

ON SUNDAY...AN UPPER TROUGH APPROACHING THE WEST COAST WILL CAUSE
THE UPPER RIDGE TO AMPLIFY OVER THE NORTHERN PLAINS. THE THERMAL
RIDGE WILL BEGIN TO BUILD WITH A COUPLE OF WEAK WAVES. THE SURFACE
BOUNDARY WILL THEN LIFT INTO MT/ND/NORTHWEST SD...FOCUSING TSRA
ACTIVITY. SUMMER-LIKE TEMPERATURES FORESEEN. SHEAR AGAIN SUFFICIENT
FOR ISOLATED SEVERE THUNDERSTORMS DURING PEAK HEATING.

MONDAY...UPPER TROUGH AND THERMAL RIDGE BUILD OVER THE CWA. FORECAST
SOUNDINGS SUGGEST WE/LL BE CAPPED WITH PLENTY OF SUNSHINE AND
TEMPERATURES ABOVE 90F OVER MANY LOCATIONS.

EXTENDED...AN UPPER RIDGE WILL SET UP ACROSS THE SOUTHERN PLAINS FOR
THE SECOND HALF OF THE WORK WEEK. DEEP SOUTHWEST FLOW ALOFT WILL
DEVELOP ACROSS THE REGION WITH SEVERAL DISTURBANCES CROSSING THE
AREA. THIS WILL BRING A NEAR DAILY CHANCE OF SHOWERS AND
THUNDERSTORMS TO THE FORECAST AREA. TEMPERATURES WILL BE NEAR TO
SLIGHTLY ABOVE AVERAGE.

&&

.AVIATION...SHOWERS AND STORMS WILL CONTINUE INTO THE EARLY EVENING
BEFORE DISSIPATING. MVFR CONDITIONS ARE POSSIBLE IN AND AROUND THE
PRECIPITATION. OTHERWISE VFR CONDITIONS EXPECTED THROUGH SUNDAY
MORNING.

&&

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

$$

000
FXUS65 KCYS 042058
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
258 PM MDT SAT JUL 4 2009

.SHORT TERM...TONIGHT THROUGH MONDAY...
MOST OF THE TSTMS THIS AFTERNOON HAVE BEEN ALONG AND SOUTH OF I-80
FROM KCYS TO KRWL BUT MORE RECENTLY THERE ARE A FEW MORE STORMS
FURTHER TO THE NORTH AND EAST. RATHER COOLISH TEMPS ARE KEEPING
INSTABILITY DOWN FROM YESTERDAY WITH GENERALLY -1 TO -3 LIFTED
INDICES OVER CWA. SO...DESPITE GOOD DIRECTIONAL WIND SHEAR AND
MOISTURE ALONG WITH UPPER DISTURBANCE MOVING THIS WAY OUT OF
NORTHERN UT AND SW WY...SEVERE TSTMS NOT VERY LIKELY FROM NOW INTO
THIS EVENING. THERE WILL BE AT LEAST A SCATTERED COVERAGE OF
WEAKER TSTMS THOUGH WITH LOWEST POPS CONFINED TO FAR EASTERN CWA.
A FEW SHOWERS AND SOME LOW CLOUDS MAY OCCUR OVER PARTS OF EASTERN
CWA LATE TONIGHT. ON SUNDAY...BETTER INSTABILITY AND DIRECTIONAL
WIND SHEAR OVER EASTERN CWA WILL COMBINE WITH SLIGHTLY INCREASING
NW FLOW ALOFT OVER SSE SURFACE WINDS. ANOTHER ROUND OF SCATTERED
AFTERNOON AND EVENING TSTMS CAN BE EXPECTED...ESPECIALLY OVER
EASTERN HALF OF CWA WITH A FEW SEVERE TSTMS POSSIBLE. UPPER RIDGE
OVER WESTERN WY SUNDAY AFTERNOON WILL FINALLY SHIFT OVER OUR CWA
ON MONDAY FOR A DRIER AND WARMER DAY. NAM SHOWS SOME QPF IN THE
AFTERNOON WHILE GFS DOES NOT...SO DID KEEP A LOW POP FOR TSTMS.

.LONG TERM...MONDAY NIGHT THROUGH FRIDAY...
A SLIGHT CHANCE OF THUNDERSTORMS IS EXPECTED TO CONTINUE THROUGH
EARLY MONDAY EVENING. HOWEVER...STORMS ARE ANTICIPATED TO BE RATHER
WEAK. BOTH THE ECMWF AND NAM INDICATED SHOWERS LINGERING INTO THE
LATE EVENING...BUT THE GFS DOES NOT INDICATE ANY PRECIPITATION.
HAVE DECIDED TO AT LEAST MENTION A SLIGHT CHANCE AND DECREASE
THUNDERSTORMS QUICKLY BEFORE MIDNIGHT. THE RIDGE OF HIGH PRESSURE
CONTINUES TO SLIDE EASTWARD OVER THE AREA. THIS WILL ALLOW FOR
RATHER WARM TEMPERATURES ACROSS SOUTHEAST WYOMING AND THE NEBRASKA
PANHANDLE. ALTHOUGH TEMPERATURES WILL BE NEARLY 8 TO 10F DEGREES
ABOVE NORMAL...THEY WILL STILL BE NEARLY 10F DEGREES BELOW RECORD
HIGHS. TEMPERATURES ON TUESDAY WILL BE IN THE UPPER 80S TO MID
90S. SHOULD EXPECT TO SEE CHANCES OF THUNDERSTORMS DECREASING WITH
THE HIGH PRESSURE WITH LACK OF MOISTURE. HOWEVER...THE NAM IS
INDICATING SOME THUNDERSTORMS DEVELOPING LATE IN THE AFTERNOON ON
TUESDAY AND QUICKLY FADING. HOWEVER...WITH THE RIDGE WILL KEEP ANY
CHANCES OF THUNDERSTORMS AT A MINIMUM ON TUESDAY AND WEDNESDAY.
WEDNESDAY WILL BE THE WARMEST DAY THROUGH THE EXTENDED PERIOD WITH
HIGH TEMPERATURES REACHING UP TO 90S FOR AREAS EAST OF INTERSTATE
25 AND IN THE MID 80S FOR AREAS WEST OF INTERSTATE 25. AS THE
RIDGE IS SLOWLY DEPARTING OVER WYOMING AND THE NEBRASKA PANHANDLE
A SURFACE HIGH PRESSURE BUILDS OVER NORTHEAST COLORADO WITH THE
SURFACE LOW SLIDES ACROSS SOUTH DAKOTA. THE TIGHTENING OF THE
PRESSURE GRADIENT WILL ALLOW FOR BREEZY SOUTHWEST TO WESTERLY
WINDS ACROSS SOUTHEAST WYOMING. SO...IT WILL BE ARE WARM BREEZY
DAY ON WEDNESDAY. CERTAINLY THERE ARE SOME DIFFERENCES BETWEEN THE
ECMWF AND GFS...WITH THE ECMWF MUCH QUICKER MOVING THE UPPER LEVEL
RIDGE EASTWARD AND HAVING THE UPPER LEVEL LOW OVER MONTANA. IN
EITHER MODEL THE RIDGE WILL GET FLATTENED AND TEMPERATURES BE
SLIGHTLY COOLER BY THURSDAY AND FRIDAY. CHANCES OF PRECIPITATION
WILL INCREASE BY THE END OF NEXT WEEK.

&&

.AVIATION...
SOME MVFR AND EVEN LOCAL IFR CEILINGS AND VSBYS WILL LIKELY OCCUR
AGAIN LATE TONIGHT AND PERSIST THROUGH MID MORNING SUNDAY OVER
NEBRASKA PANHANDLE. A SCATTERED COVERAGE OF THUNDERSTORMS WILL BE
OVER CWA INTO THIS EVENING AND OVER MUCH OF CWA SUNDAY AFTERNOON
AND EVENING WITH A FEW STRONG STORMS BRIEFLY CAUSING MVFR CEILINGS
AND VISIBILITIES IN RAIN. OTHERWISE...VFR CONDITIONS ARE EXPECTED.

&&

.FIRE WEATHER...
SLIGHTLY BELOW NORMAL TEMPS AND INCREASED HUMIDITIES WILL PERSIST
THROUGH SUNDAY ALONG WITH SCATTERED AFTERNOON AND EVENING TSTMS.
THE WEATHER PATTERN WILL BECOME WARMER AND DRIER STARTING ON MONDAY
WITH ABOVE NORMAL TEMPERATURES BY THE MID PART OF NEXT WEEK. THERE
WILL BE A MINIMUM OF LATE DAY STORM ACTIVITY FOR MOST OF NEXT
WEEK. MINIMUM RELATIVE HUMIDITIES WILL DROP TO 15 TO 20 PERCENT IN
THE WYOMING PART OF THE CWA DURING THAT TIME. CURRENT FUELS STATUS
INDICATES THAT FUELS HAVE BEEN DRYING AND THIS WILL CONTINUE FOR
NEXT WEEK WHICH WILL START TO INCREASE FIRE WEATHER CONCERNS.

&&

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.

&&

$$

SHORT TERM/AVIATION...JLH
LONG TERM....MG

000
FXUS63 KUNR 041700
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
1058 AM MDT SAT JUL 4 2009

.DISCUSSION...REMAINING LOW STRATUS OVER PARTS OF WESTERN AND
CENTRAL SOUTH DAKOTA SHOULD MIX INTO A CU DECK DURING THE EARLY
AFTERNOON. CAP WILL WEAKEN ENOUGH FOR NEW CONVECTION BY
18Z...ESPECIALLY OVER NORTHEASTERN WYOMING AND THE BLACK HILLS AREA.
THIS ACTIVITY WILL CONTINUE INTO THE EVENING HOURS. MAIN THREAT
FOR SEVERE WEATHER WILL BE WEST OF THE CWA AHEAD OF AN APPROACHING
WAVE...AND NEAREST SURFACE BOUNDARY. SHEAR WILL BE SUFFICIENT FOR
ISOLATED STRONG TO SEVERE THUNDERSTORMS DURING PEAK HEATING.

SUNDAY...UPPER TROUGH APPROACHING THE WEST COAST ALLOWING UPPER
RIDGE TO AMPLIFY OVER THE NORTHERN PLAINS. THERMAL RIDGE BEGINS TO
BUILD WITH A COUPLE OF WEAK WAVES. THE SURFACE BOUNDARY WILL LIFT
INTO MT/ND/NORTHWEST SD...FOCUSING TSRA ACTIVITY. SUMMER-LIKE
TEMPERATURES FORESEEN. SHEAR AGAIN SUFFICIENT FOR ISOLATED SEVERE
THUNDERSTORMS DURING PEAK HEATING.

MONDAY...UPPER LOW DEVELOPS NEAR OR WITH UPPER/THERMAL RIDGE OVER
THE CWA. FORECAST SOUNDINGS SUGGEST WE/LL BE CAPPED WITH PLENTY OF
SUNSHINE AND TEMPERATURES ABOVE 90F OVER MANY LOCATIONS.

EXTENDED...AN UPPER RIDGE IS FORECAST TO TAKE UP A POSITION OVER THE
NORTHERN PLAINS FOR THE MIDDLE OF NEXT WEEK. THIS WILL RESULT IN A
PERIOD OF WARMER AND DRIER WEATHER. BY THE END OF THE WEEK THE GFS
SHOWS A MORE ZONAL/ACTIVE PATTERN WHILE THE ECMWF REDEVELOPS A WRN
U.S. RIDGE. THE CURRENT FORECAST PACKAGE REINTRODUCES A SLGT
CHANCE FOR MOST AREAS THU NIGHT WHICH IS A PRETTY GOOD COMPROMISE
AT THIS POINT.

&&

.AVIATION...WIDESPREAD MVFR...WITH LOCALIZED IFR...CONDS CONTINUE
FROM THE BLKHLS EWD AND INTO SOUTHWESTERN AND SOUTH CENTRAL SOUTH
DAKOTA.   CIGS AND VSBYS ARE EXPECTED TO IMPROVE DURING THE
AFTERNOON IN WRN SOUTH DAKOTA AS THE UPPER LEVEL SHORT WAVE AND
ASSCD SFC TROUGH MOVE OUT OF THE AREA. THERE IS A CHANCE OF
AFTERNOON AND EVENING THUNDERSTORMS...ESPECIALLY ACROSS NORTHEASTERN
WYOMING...AND OVER AND NEAR THE BLACKH HILLS.

&&

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

$$

HELGESON/CARPENTER

000
FXUS65 KRIW 040931
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
331 AM MDT SAT JUL 4 2009

.SHORT TERM...TODAY THROUGH MONDAY NIGHT
FLASH FLOODING HAS SUBSIDED AROUND CASPER SINCE LATE LAST EVENING.
VERY HEAVY RAIN FELL OVER THE AREA WITH MILLS PICKING UP AN INCH OF
RAIN IN 13 MINUTES.  LOW LYING AREAS OF ROADS INCLUDING I25 HAD 1 TO
3 FEET OF STANDING WATER WITH WATER ENTERING NUMEROUS BASEMENTS OF
HOMES AND BUILDINGS.  THE RAINFALL ONLY LASTED 20 MINUTES...BUT TOOK
6 HOURS FOR THE WATER TO DRAIN.

PACIFIC SHORTWAVE MOVING INTO NORTHERN NEVADA THIS MORNING AND LOOKS
TO MOVE ACROSS WYOMING THIS AFTERNOON AND EVENING.  EXPECT MUCH THE
SAME TO CONTINUE TODAY WITH PWATS STILL IN THE 0.75" RANGE AND LOW
TO MODERATE INSTABILITY.  ALSO WILL HAVE LOW LEVEL EAST TO NORTHEAST
FLOW BRINGING IN THE LOW LEVEL FLOW.  THIS COMBINED WITH A WEST
NORTHWEST FLOW ALOFT WILL MAKE FOR SOME DECENT WIND SHEAR OVER THE
EASTERN ZONES.  SO COULD SEE SOME SEVERE THUNDERSTORMS THERE.  HEAVY
RAINFALL WILL ALSO BE A THREAT TODAY...RAISING THE FLASH FLOOD
THREAT.  NORTHWEST FLOW BUILDS IN BEHIND THE SHORTWAVE WITH
TRANSITORY RIDGE MOVING INTO THE EASTERN GREAT BASIN.  THE RIDGE
WILL STAY PUT HERE SUNDAY WITH LESS MOISTURE ROTATING THROUGH.
STILL WILL HAVE LINGERING LOW LEVEL MOISTURE TO ALLOW FOR
THUNDERSTORMS TO FIRE.  SHOULD BE MAINLY GARDEN VARIETY WITH THE
FLASH FLOOD THREAT SIGNIFICANTLY LESS THAN PREVIOUS DAYS.  RIDGE
SHIFTS EAST ACROSS WYOMING MONDAY AS PACIFIC UPPER LOW APPROACHES
THE PAC NW COAST.  THIS WILL USHER MUCH DRIER AND WARMER AIR OVER
THE CWA.  THUNDERSTORM ACTIVITY WILL BE MUCH LESS UNDER THESE
CONDITIONS.

.LONG TERM...TUESDAY THROUGH SATURDAY
ECMWF/GFS AND GEFS MEAN CONTINUE IN GOOD AGREEMENT WITH CLOSED LOW
OFF OF NW COAST EJECTING SEVERAL SHORTWAVES NE INTO CENTRAL CANADA
OVER STRONG RIDGE OVER THE PLAINS. WYOMING WILL MOSTLY REMAIN
UNDER INFLUENCE OF DRY AND WARM SOUTHWEST FLOW WITH SHORTWAVES
PUSHING MOSTLY DRY FRONTS INTO THE NORTH TUESDAY NIGHT AND
WEDNESDAY NIGHT. FORECAST KEEPS LOW POPS NEAR THE FRONT ACROSS
THE FAR NORTH. H7 TEMPERATURES ACROSS THE SOUTH AND CENTRAL FROM
16C-18C...SO BREEZY TO WINDY AND VERY DRY CONDITIONS WILL RESULT
IN TEMPERATURES IN THE MID 80S TO MID 90S ALONG WITH LOW RH/S
MOSTLY IN THE 10-15 PERCENT RANGE. THIS PATTERN WILL DRY OUT FINE
FUELS AND INCREASE THE FIRE DANGER THROUGH THE WEEK. UPPER LOW
OVER THE NORTHWEST TO WEAKEN/FILL FRIDAY AND SATURDAY WITH UPPER
HIGH CENTERED OVER NEW MEXICO STRENGTHENING AND EXPANDING ACROSS
THE ROCKY MOUNTAIN REGION. THIS PATTERN SHOULD BRING BACK THE
RETURN OF MONSOONAL MOISTURE NEXT WEEKEND WITH FORECAST BRINGING
SLIGHT CHANCES OF LATE DAY THUNDERSTORMS OVER THE SOUTHWEST
SATURDAY.

&&

.AVIATION...

ANOTHER ACTIVE CONVECTIVE DAY IS EXPECTED ACROSS THE REGION
TODAY...AS THE VERY MOIST AND UNSTABLE ATMOSPHERE REMAINS OVER THE
AREA. CONVECTION IS EXPECTED TO RAPIDLY DEVELOP LATE IN THE
MORNING...AND BECOMING SCATTERED TO LOCALLY NUMEROUS DURING THE
AFTERNOON. IFR/MVFR CONDITIONS WILL BE PRESENT IN AND AROUND
THUNDERSTORMS.  WINDS WILL GENERALLY BE RELATIVELY LIGHT...EXCEPT
WINDS OF COURSE WILL BE ERRATIC AND GUSTY DURING THE AFTERNOON DUE
TO THE SCATTERED TO NUMEROUS THUNDERSTORMS.

&&

.FIRE WEATHER...

THE HUMID CONDITIONS CONTINUE TODAY WITH ANOTHER ROUND OF SHOWERS
AND THUNDERSTORMS EXPECTED.  HEAVY RAINFALL...SMALL HAIL FREQUENT
LIGHTNING AND GUSTY WINDS WILL BE THE MAIN THREATS.  SEVERE
THUNDERSTORMS ARE POSSIBLE OVER NATRONA AND JOHNSON COUNTIES.
THUNDERSTORM ACTIVITY WILL DECREASE SOME FOR SUNDAY...WITH THE
THREAT FOR HEAVY RAIN DECREASING.  MUCH DRIER AND WARMER AIR MOVES
IN MONDAY WITH MAINLY ISOLATED THUNDERSTORMS EXPECTED IN THE
AFTERNOON AND EVENING.  SOUTHWEST WINDS WILL ALSO BE ON THE INCREASE.


&&

.RIW WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SHORT TERM...TWB
LONG TERM...AEM
AVIATION...WM
FIRE WEATHER...TWB

000
FXUS65 KCYS 040924
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
323 AM MDT SAT JUL 4 2009

.SHORT TERM...TODAY THROUGH SUNDAY NIGHT...
SHOWERS ENDED OVER THE CWA WITHIN THE PAST HOUR.  BOUNDARY LAYER IS
CURRENTLY MOIST WITH THE TEMPERATURE-DEW POINT SPREAD A FEW DEGREES
IN MANY PLACES.  WITH THE LIGHT WINDS AND CLEARING MID AND HIGH
CLOUDS EXPECT THE CURRENT AREAS OF LOW CLOUDS TO EXPAND OVER MUCH OF
THE CWA WITH AREAS OF FOG FORMING.  CLOUD BASES WILL GRADUALLY LIFT
THROUGH THE MORNING...BUT THE CLOUDS WILL SLOW THE DAYTIME HEATING.
THE PRECIPITABLE WATER VALUES WILL CONTINUE TO DIMINISH SOME TODAY
AND TONIGHT WITH MOST PLACES DOWN TO THREE QUARTERS OF AN INCH.
THUNDERSTORMS FOR THIS AFTERNOON AND EARLY TONIGHT WILL BE INITIATED
BY AN APPARENT SHORTWAVE TROUGH ENTERING WESTERN UTAH AND WESTERN
WYOMING EARLY THIS MORNING.  THE ATMOSPHERE OVER THE WYOMING PART OF
THE CWA WILL BECOME UNSTABLE AND THAT IS WHERE MOST OF THE STORMS
WILL BE LOCATED LATER TODAY.  MEANWHILE OVER THE PANHANDLE THE
ATMOSPHERE APPEARS THAT IT WILL BE CAPPED AS SURFACE HIGH PRESSURE
MOVES OVER THE NORTHERN AND CENTRAL PLAINS.  SOME OF THE STORMS WILL
PRODUCE SMALL HAIL...GUSTY WINDS AND HEAVY RAIN IN SOUTHEAST
WYOMING...BUT NOT SURE THE SEVERE POTENTIAL WILL BE AS MUCH AS SPC
OUTLOOK FOR LATER TODAY.  MOISTURE INCREASES LATER TONIGHT AND SUNDAY
IN THE SOUTHERLY RETURN FLOW OVER MUCH OF THE CWA.  MODELS DEPICT
SOME QPF OVER THE PANHANDLE LATER TONIGHT...WITH THE NAM BEING THE
MOST WIDESPREAD BY FAR.  FOR NOW WILL KEEP LOW POPS OVER THE
PANHANDLE LATER TONIGHT.  FOG AND LOW CLOUDS MAY AGAIN BE A
POSSIBILITY AS WELL OVER THAT PART OF THE CWA LATE TONIGHT THROUGH
MID MORNING SUNDAY.  THUNDERSTORMS WILL AGAIN DEVELOP SUNDAY
AFTERNOON OVER THE MOUNTAINS AND THEN MOVE EAST WITH THE CAP
BREAKING IN THE PANHANDLE.  DRIER AIR WILL MOVE OVER THE CWA LATER
SUNDAY NIGHT FOR CLEARING SKIES.  TEMPERATURES WILL BE BELOW NORMAL
TODAY AND BE AT OR JUST BELOW NORMAL FOR SUNDAY.  IN GENERAL HAVE
BUMPED UP POPS IN THE WYOMING PART OF THE CWA THIS AFTERNOON AND
EVENING AND OVER THE ENTIRE CWA FOR SUNDAY AFTERNOON AND EVENING.

.LONG TERM...MONDAY THROUGH FRIDAY
HOT AND DRIER CONDITIONS ARE EXPECTED IN THE EXTENDED PERIOD.  ON
MON....AN UPPER RIDGE WILL MOVE ACROSS THE AREA.  SOME AFTERNOON
THUNDERSTORMS WILL OCCUR WEST OF THE LARAMIE RANGE WHERE AIRMASS
WILL BE UNSTABLE ALONG WITH RESIDUAL MID LEVEL MOISTURE FROM THE
SOUTH.  ON TUE...SW FLOW WILL DEVELOP ALOFT AS AN UPPER TROUGH MOVES
INTO THE PAC NW.  FOR WED...THE SW FLOW WILL CONT ALOFT AS A SERIES
OF DISTURBANCES MOVE ACROSS THE PAC NW.  ON THUR...THE UPPER RIDGE
WILL BEGIN TO REBUILD OVER THE CENTRAL ROCKIES.  A SURFACE COLD
FRONT MAY ALSO MOVE ACROSS THE CWA ON THUR.  THIS WILL RESULT IN A
SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS FROM THUR NIGHT THROUGH
FRI AFTERNOON.  THE UPPER RIDGE WILL AMPLIFY OVER THE ROCKIES INTO
THE WEEKEND.  HIGH TEMPERATURES WILL BE AROUND NORMAL ON MON...THEN
5 TO 8 DEGREES ABOVE NORMAL FOR TUE THROUGH FRI.

&&

.AVIATION...IFR CEILINGS WERE LOCATED OVER THE NORTHERN PANHANDLE
EARLY THIS MORNING WITH LOW CEILINGS AND VISIBILITIES IN FOG IN THE
LARAMIE VALLEY.  EXPECT THE IFR CEILINGS AND VISIBILITIES IN FOG TO
SPREAD OVER MUCH OF THE REST OF THE CWA BY SUNRISE.  THOSE CONDITIONS
WILL GRADUALLY LIFT THROUGH LATE MORNING TO VFR.  THE LOW CLOUDS AND
FOG WILL LIKELY FOR AGAIN LATER TONIGHT AND PERSIST THROUGH MID
MORNING SUNDAY OVER THE NEBRASKA PANHANDLE.  A SCATTERED COVERAGE OF
THUNDERSTORMS WILL BE OVER MAINLY THE WYOMING PART OF THE CWA THIS
AFTERNOON AND EVENING AND OVER MUCH OF THE CWA SUNDAY AFTERNOON AND
EVENING.  BRIEF MVFR CEILINGS AND VISIBILITIES IN RAIN WILL BE
ASSOCIATED BOTH DAYS WITH THE STRONGER STORMS.

&&

.FIRE WEATHER...THROUGH SUNDAY THE TEMPERATURES WILL BE SLIGHTLY
BELOW NORMAL AND THERE WILL BE CHANCES OF SHOWERS AND THUNDERSTORMS
EACH AFTERNOON AND EVENING.  THE ACTIVITY WILL BE MAINLY OVER THE
SOUTHEAST WYOMING PART OF THE CWA THIS AFTERNOON AND EVENING AND
OVER THE ENTIRE CWA SUNDAY AFTERNOON AND EVENING.  THE WEATHER
STARTS TO WARM AND DRY STARTING ON MONDAY WITH ABOVE NORMAL
TEMPERATURES BY THE MID PART OF NEXT WEEK.  THERE WILL BE A MINIMUM
OF LATE DAY STORM ACTIVITY FOR MOST OF NEXT WEEK.  MINIMUM RELATIVE
HUMIDITIES WILL DROP TO 15 TO 20 PERCENT IN THE WYOMING PART OF THE
CWA DURING THAT TIME.  CURRENT FUELS STATUS INDICATES THAT FUELS
HAVE BEEN DRYING AND THIS TREND WILL CONTINUE FOR NEXT WEEK WHICH
WILL START TO INCREASE FIRE WEATHER CONCERNS.

&&

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.

&&

$$

WEILAND/KMD

000
FXUS63 KUNR 040845
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
245 AM MDT SAT JUL 4 2009

.DISCUSSION...08Z SURFACE ANALYSIS HAD LOW OVER SOUTHEAST NE WITH
BOUNDARY SOUTHWEST INTO NORTHEAST CO AND THEN NORTHWEST INTO
CENTRAL MT. WATER VAPOUR HAD SHORTWAVE MOVING ACROSS EASTERN MT
INTO ND...HELPING SOME CONVECTION IN SOUTHEAST MT. THIS ACTIVITY
WILL SINK INTO THE CWA THIS MORNING. ADDITIONAL LIGHT -SHRA NOTED
OVER THE CWA. T/TD SPREADS CLOSE AND WOULD EXPECT AREAS OF FOG TO
CONTINUE THROUGH 15Z. FG/ST SHOULD QUICKLY MIX INTO A CU DECK
WITH CAP WEAKENING ENOUGH FOR NEW CONVECTION BY 18Z. THIS ACTIVITY
WILL CONTINUE THROUGH THE EVENING HOURS. MAIN THREAT FOR SEVERE
WEATHER WILL BE WEST OF THE CWA AHEAD OF AN APPROACHING WAVE...AND
NEAREST SURFACE BOUNDARY. SHEAR WILL BE SUFFICIENT FOR ISOLATED
SEVERE THUNDERSTORMS DURING PEAK HEATING ANYWHERE.

SUNDAY...UPPER TROUGH APPROACHING THE WEST COAST ALLOWING UPPER
RIDGE TO AMPLIFY OVER THE NORTHERN PLAINS. THERMAL RIDGE BEGINS TO
BUILD WITH A COUPLE OF WEAK WAVES. THE SURFACE BOUNDARY WILL LIFT
INTO MT/ND/NORTHWEST SD...FOCUSING TSRA ACTIVITY. SUMMER-LIKE
TEMPERATURES FORESEEN. SHEAR AGAIN SUFFICIENT FOR ISOLATED SEVERE
THUNDERSTORMS DURING PEAK HEATING.

MONDAY...UPPER LOW DEVELOPS NEAR OR WITH UPPER/THERMAL RIDGE OVER
THE CWA. FORECAST SOUNDINGS SUGGEST WE/LL BE CAPPED WITH PLENTY OF
SUNSHINE AND TEMPERATURES ABOVE 90F OVER MANY LOCATIONS.

EXTENDED...AN UPPER RIDGE IS FORECAST TO TAKE UP A POSITION OVER THE
NORTHERN PLAINS FOR THE MIDDLE OF NEXT WEEK. THIS WILL RESULT IN A
PERIOD OF WARMER AND DRIER WEATHER. BY THE END OF THE WEEK THE GFS
SHOWS A MORE ZONAL/ACTIVE PATTERN WHILE THE ECMWF REDEVELOPS A WRN
U.S. RIDGE. THE CURRENT FORECAST PACKAGE REINTRODUCES A SLGT
CHANCE FOR MOST AREAS THU NIGHT WHICH IS A PRETTY GOOD COMPROMISE
AT THIS POINT.

&&

.AVIATION...WIDESPREAD IFR CONDS CONTINUE FROM THE BLKHLS EWD AND
NORTH INTO ERN MT.  WEST OF THE BLKHLS IN NERN WYOMING SKIES HAVE
CLEARED BUT THERE IS A THREAT OF MORE SHOWER ACTIVITY MOVING INTO
THE AREA FROM ERN MT LATER THIS MORNING.  CIGS AND VSBYS ARE
EXPECTED TO IMPROVE BY MID DAY IN WRN SOUTH DAKOTA AS THE UPPER
LEVEL SHORT WAVE AND ASSCD SFC TROUGH MOVE OUT OF THE AREA. VFR
CONDITIONS SHOULD BE THE RULE ACROSS THE ENTIRE CWFA BY LATE
AFTERNOON.

&&

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

$$

HELGESON/CARPENTER

000
FXUS65 KCYS 032135
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
335 PM MDT FRI JUL 3 2009

.SHORT TERM...TONIGHT THROUGH SUNDAY...
DECENT SHORTWAVE TROUGH MOVED INTO NEBRASKA PANHANDLE EARLY THIS
AFTERNOON BUT WATER VAPOR SATELLITE LOOP STILL SHOWS ANOTHER WEAK
FEATURE OR TWO MOVING OUR WAY. SO...EXPECTING SCATTERED TSTMS TO
PERSIST INTO THE MID EVENING HOURS...A FEW POSSIBLY SEVERE IN THE
NEBRASKA PANHANDLE PER SVR TSTM WATCH 541. WESTERLY FLOW ALOFT
CURRENTLY WILL BACK TO WNW SATURDAY AND MORE NW SUNDAY AHEAD OF
UPPER RIDGE BUILDING OVER WESTERN U.S. MOISTURE AND INSTABILITY
WILL REMAIN IN PLACE FOR SOME AFTERNOON/EVENING TSTMS BOTH FOR THE
4TH HOLIDAY AND SUNDAY. FOR THE 4TH...MODELS NOT SO KEEN SHOWING
THAT MUCH INSTABILITY IN PANHANDLE KEEPING THINGS MAINLY IN SMALL
AREA OF SOUTHEAST WY WHERE BEST WIND CONVERGENCE WILL BE WHILE
WINDS OVER PANHANDLE REMAIN FROM NNE. ON SUNDAY...THE SURFACE WIND
CONVERGENCE WILL EXTEND OVER MUCH BIGGER AREA FROM I-25 EASTWARD.

.LONG TERM...SUNDAY NIGHT THROUGH FRIDAY.
PRECIPITATION WILL BE LIMITED TO AFTERNOON AND EVENING CONVECTION
OVER MAINLY THE HIGHER TERRAIN FOR THE UPCOMING WEEK...AS
THE ATMOSPHERE DRIES OUT AS AN UPPER RIDGE SETS UP ACROSS
SOUTHEAST WYOMING AND THE NEBRASKA PANHANDLE.

THE RIDGE IS BUILDING AHEAD OF AN UPPER LOW NOW OVER THE NORTH
PACIFIC WHICH WILL DROP SOUTHEAST INTO THE PACIFIC NORTHWEST BY
MID WEEK AND BECOME STATIONARY. THIS WILL ALLOW FOR INCREASING
SOUTHWEST FLOW ALOFT...BUT ANY EMBEDDED SHORT WAVE ENERGY AND
PRECIPITATION CHANCES WILL REMAIN NORTH OF THE AREA.

&&

.AVIATION...
THUNDERSTORMS THIS EVENING OVER MUCH OF THE CWA WILL PRODUCE BRIEF
MVFR CEILINGS AND VISIBILITIES IN RAIN. SOME MVFR CEILINGS AND
VISIBILITIES IN FOG CAN BE EXPECTED EAST OF THE LARAMIE RANGE
BETWEEN 09Z AND 15Z SATURDAY MORNING. OTHERWISE...VFR CONDITIONS
WILL PREVAIL TONIGHT AND SATURDAY WITH A SMALLER COVERAGE OF
AFTERNOON AND EVENING TSTMS SAT AFTERNOON MAINLY JUST IN SE WY.

&&

.FIRE WEATHER...
MINIMAL CONCERN STILL INTO SUNDAY WITH GREEN FUELS...FAIRLY HIGH
RELATIVE HUMIDITIES AND TEMPS NOT BEING ALL THAT WARM. CONDITIONS
WILL WARM AND DRY NEXT WEEK WITH WELL ABOVE NORMAL TEMPERATURES
BY THE MID PART OF THE WEEK AND A MINIMUM OF LATE DAY STORM
ACTIVITY. MINIMUM RELATIVE HUMIDITIES WILL BE DROPPING TO 15 TO 20
PERCENT IN THE WYOMING PART OF THE CWA AS WELL. FUELS WILL BE
DRYING NEXT WEEK WHICH WILL INCREASE FIRE WEATHER CONCERNS.

&&

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.

&&

$$

SHORT TERM/AVIATION...JLH
LONG TERM...EISE

000
FXUS65 KRIW 032121
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
320 PM MDT FRI JUL 3 2009

.SHORT TERM...TONIGHT THROUGH MONDAY

SHOWERS AND STORMS HAVE ERUPTED AGAIN THIS AFTERNOON OVER THE NORTH
AND CENTRAL. LESS ACTIVITY IN THE SOUTH SO FAR BUT DO EXPECT SOME
STORMS TO GET GOING SOON. UPPER LEVEL DISTURBANCE HAS MOVED EAST OF
THE REGION AND HAS PUSHED SOME OF THE DEEPER MOISTURE EAST OF
US...BUT ENOUGH LOW LEVEL DEWPOINT AND SUNSHINE TO GET CONVECTION
FIRED UP. HAVE MADE SOME ADJUSTMENTS FOR THE REST OF THE DAY INTO
THE EVENING HOURS FOR STORM COVERAGE. CONVECTION WILL BECOME MORE
ISOLATED AFTER MIDNIGHT. ON SATURDAY...ANOTHER DISTURBANCE IN THE
WEST FLOW ALOFT IS FORECAST TO MOVE TOWARD WESTERN WY BY LATE
AFTERNOON. IF THE TIMING IS RIGHT...THEN SCATTERED SHOWERS AND
STORMS WILL FORM AND SOME OF THE STORMS WILL HAVE HEAVY RAIN. THE
LOW LEVEL MOISTURE WILL BE AVAILABLE AND WITH AMPLE HEATING AND
DECENT SHEAR PROFILE...SOME STORMS WILL BE STRONG TO POTENTIALLY
SEVERE EAST OF THE DIVIDE. AGREE WITH DAY 2 OUTLOOK AND THIS MAY
NEED TO BE EXPANDED A BIT IF CONDITIONS WARRANT TOMORROW. SHOWERS
AND STORMS WILL PERSIST INTO THE EVENING WITH ACTIVITY DECREASING
TOWARD MIDNIGHT. ON SUNDAY...ENOUGH MOISTURE APPEARS TO BE PRESENT
FOR ANOTHER ROUND OF AFTERNOON AND EVENING STORMS OVER MUCH OF THE
REGION. THE SOUTH AND SW ZONES MAY SEE ONLY ISOLATED ACTIVITY AS
DRIER AIR MAY WORK INTO THAT REGION. ON MONDAY...SHOWERS AND STORMS
WILL BE MOST NUMEROUS OVER THE NORTH AND EAST WITH ISOLATED ACTIVITY
IN THE SOUTHWEST AND SOUTH WHERE DRIER AIR AND LOWER PRECIPITABLE
WATER VALUES ARE FORECAST. DID NOT ALTER CURRENT MONDAY FORECAST BUT
MORE ACTIVITY MAY BE NEEDED IN THE NORTH AND EAST ZONES WITH TIME IF
DRYING IS SLOWER TO OCCUR. TEMPS WILL BE WARM SAT AND SUN WITH EVEN
WARMER HIGHS ON MONDAY.

.LONG TERM...MONDAY NIGHT THROUGH FRIDAY

ECMWF/GFS AND GEFS MEAN IN OVERALL GOOD AGREEMENT WITH SYNOPTIC
PATTERN IN THIS PERIOD WITH TROUGH OVER NORTHWEST U.S. AND
STRENGTHENING RIDGE OVER THE SOUTHERN AND CENTRAL PLAINS.  THIS
WILL PUT MOST OF WYOMING UNDER DRY AND WARM SOUTHWEST FLOW.
PREFERRED ECMWF SLOWER TO MOVE MONSOONAL MOISTURE OUT OF AREA MONDAY
NIGHT THAN GFS...AND FORECAST KEEPS SLIGHT CHANCES OF EVENING
THUNDERSTORMS ACROSS THE NORTH AND EAST. WARM AND DRY SW FLOW
PREVAILS ON TUESDAY WITH ECMWF AND GFS FLIP-FLOPPING...THE GFS NOW
THE WARMER OF THE TWO WITH H7 TEMPS NEAR 18C. ECMWF AND GFS IN
GOOD AGREEMENT EJECTING SHORTWAVE NE ACROSS IDAHO INTO WESTERN
MONTANA WEDNESDAY AFTERNOON AND EVENING WITH NORTHWEST AND FAR
NORTH WYOMING ON THE FRINGE OF BETTER MOISTURE AND INSTABILITY.
BREEZY TO WINDY AND HOT CONDITIONS WILL PREVAIL OVER THE CENTRAL
AND SOUTH. RIDGE OVER THE CENTRAL AND SOUTHERN PLAINS EXPANDS INTO
SOUTHERN/CENTRAL ROCKIES THURSDAY AND FRIDAY WITH WEAKER FILLING
UPPER LOW LEFT OVER NW U.S. MOSTLY DRY CONDITIONS WITH NEAR OR
ABOVE NORMAL TEMPERATURES (ABOVE MOST GUIDANCE NUMBERS) FORECAST
FOR THIS LATTER PERIOD.

&&

.AVIATION...

UPPER LEVEL HIGH PRESSURE WILL MOVE ACROSS THE REGION TONIGHT
THROUGH SATURDAY....AND WIND SPEEDS WILL REMAIN LIGHT. ABUNDANT
MOISTURE AND WEAK INSTABILITY EAST OF THE DIVIDE WILL ALLOW SHOWERS
AND ISOLATED THUNDERSTORMS TO CONTINUE THROUGH THE MID TO LATE
EVENING HOURS TONIGHT WITH MVFR VISIBILITIES POSSIBLE IN
THUNDERSTORMS. DAYTIME HEATING AND ABOVE NORMAL MOISTURE WILL
GENERATE SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS ACROSS THE
ENTIRE REGION SATURDAY AFTERNOON AND EVENING WITH STRONG WIND
GUSTS...LARGE HAIL AND LOCALIZED MVFR CONDITIONS POSSIBLE.

&&

.FIRE WEATHER...

SCATTERED SHOWERS AND THUNDERSTORMS WILL OCCUR THE REST OF TODAY
AND THIS EVENING...DECREASING IN COVERAGE AFTER MIDNIGHT. ON
SATURDAY SCATTERED AFTERNOON AND EVENING SHOWERS AND STORMS WILL
OCCUR. SHOWERS AND THUNDERSTORM ACTIVITY ON SUNDAY AFTERNOON AND
EVENING WILL BE LESS NUMEROUS. EARLY NEXT WEEK THE WEATHER PATTERN
IS INDICATING A WARMER AND DRIER REGIME FOR THE DISTRICT.

&&

.RIW WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

SHORT TERM...AR
LONG TERM...AEM
AVIATION...SMITH
FIRE WEATHER...AR

000
FXUS63 KUNR 032100
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
300 PM MDT FRI JUL 3 2009

.DISCUSSION...20Z SFC ANALYSIS SHOWS A TROUGH OF LOW PRESSURE
EXTENDING FROM EASTERN MONTANA THROUGH EASTERN WYOMING AND INTO
EASTERN COLORADO. REGIONAL RADAR MOSAIC CONTINUES TO SHOW NUMEROUS
SHOWERS OVER PARTS OF NORTHWESTERN SOUTH DAKOTA WITH MORE SCATTERED
SHOWERS ACROSS THE REST OF THE AREA. PERSISTANT CLOUD COVER HAS
LIMITED THE THUNDERSTORM ACTIVITY OVER WESTERN SOUTH DAKOTA...BUT
BREAKS IN THE CLOUDS OVER NORTHEASTERN WYOMING AND THE NEBRASKA
PANHANDLE HAVE INCREASED THE INSTABILITY AND ALLOWED SOME
THUNDERSTORMS TO FORM. THE STRONGEST THUNDERSTORMS ARE CURRENTLY
LOCATED IN NORTH CENTRAL NEBRASKA. THERE IS A POSSIBILITY FOR
STRONGER THUNDERSTORMS TO DEVELOP OVER PARTS OF SOUTH CENTRAL SOUTH
DAKOTA LATE THIS AFTERNOON OR EARLY THIS EVENING AS INSTABILITY HAS
INCREASED OVER THOSE AREAS THIS AFTN WITH SFC CAPE INCREASING TO
AROUND 1500J/KG.

TONIGHT...SUBSIDENCE BEHIND THE MAIN WAVE SHOULD ALLOW A GRADUAL
DECREASE IN PRECIPITATION COVERAGE DURING THE EVENING. AN
INSTABILITY AXIS REMAINS IN THE FAR WEST...SO WILL KEEP LOW POPS IN
OVERNIGHT. DUE TO THE HIGH DEWPOINTS AND EASTERLY COMPONENT TO THE
SFC WIND HAVE ADDED MENTION OF FOG TONIGHT FOR MUCH OF THE SOUTH
DAKOTA PORTION OF THE FORECAST AREA AND A FEW PARTS OF NORTHEASTERN
WYOMING.

SATURDAY/SUNDAY...UPPER RIDGE BUILDS OVER THE WEST AND SHIFTS INTO
THE PLAINS. SEVERAL WAVES WILL BRING CHANCES FOR TSRA. HIGHS WILL
BE ON THE UPSWING AS THERMAL RIDGE ENVELOPS THE REGION.

EXTENDED...AN ACTIVE WEATHER PATTERN WILL SLOWLY TRANSITION TO A
QUIETER PATTERN AS AN UPPER RIDGE BUILDS OVER THE NORTHERN PLAINS
EARLY NEXT WEEK. THIS WILL BRING DRIER WEATHER AND WARMER
TEMPERATURES. SOUTHWEST FLOW ALOFT WILL DEVELOP ACROSS THE REGION
FOR THE SECOND HALF OF THE WEEK. THIS WILL REINTRODUCE CHANCES FOR
SHOWERS AND THUNDERSTORMS.

&&

.AVIATION...SHOWERS AND ISOLATED THUNDERSTORMS WILL CONTINUE THIS
THIS EVENING...BEFORE DECREASING LATER TONIGHT. IFR CONDITIONS WILL
CONTINUE TONIGHT ACROSS MUCH OF THE SOUTH DAKOTA PLAINS INTO THE
EASTERN AND NORTH BLACK HILLS. OTHERWISE MVFR CONDITIONS ARE
EXPECTED WITHIN PRECIPITATION...AND VFR CONDITIONS ELSEWHERE.

&&

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

$$

000
FXUS63 KUNR 031645
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
1045 AM MDT FRI JUL 3 2009

.DISCUSSION...16Z SURFACE ANALYSIS LOWS LOW PRESSURE EXTENDING FROM
CENTRAL MONTANA ACROSS WYOMING TO NORTHEASTERN COLORADO. SOUTHERLY
WINDS HAVE POOLED ABUNDANT LOW LEVEL MOISTURE OVER FOR FORECAST
AREA...AS INDICATED BY THE STRATUS AND DEWPOINTS IN THE 60S. WV
IMAGERY SHOWS ANOTHER SHORTWAVE CROSSING WYOMING...SO EXPECTED TO
SEE SHOWERS AND THUNDERSTORMS INCREASE IN COVERAGE AND INTENSITY
AGAIN THIS AFTERNOON WITH ADDITIONAL DESTABILIZATION FROM DIURNAL
HEATING AND THE SYNOPTIC LIFT AHEAD OF THE SHORTWAVE. TEMPERATURES
ARE EXPECTED TO REMAIN RELATIVELY COOL DUE TO THE CLOUD COVER.

TONIGHT...SUBSIDENCE BEHIND MAIN WAVE SHOULD ALLOW DECREASE IN
PRECIPITATION BY EARLY EVENING. INSTABILITY AXIS DOES REMAIN IN THE
FAR WEST...SO WILL HAVE SOME LOWER POPS. WOULDN/T BE SURPRISED TO
SEE FG AFTER MIDNIGHT GIVEN ANTECEDENT MOISTURE. WITH WINDS TRENDING
NORTHERLY...WILL KEEP PATCHY WORDING.

SATURDAY/SUNDAY...UPPER RIDGE BUILDS OVER THE WEST AND SHIFTS INTO
THE PLAINS. SEVERAL WAVES WILL BRING CHANCES FOR TSRA. HIGHS WILL
BE ON THE UPSWING AS THERMAL RIDGE ENVELOPS THE REGION.

EXTENDED...AN ACTIVE WEATHER PATTERN WILL SLOWLY TRANSITION TO A
QUIETER PATTERN AS AN UPPER RIDGE BUILDS OVER THE NORTHERN PLAINS
EARLY NEXT WEEK. THIS WILL BRING DRIER WEATHER AND WARMER
TEMPERATURES. CANT RULE OUT ISOLATED THUNDERSTORMS ON ANY DAY IF A
RIDGE RIDING WAVE CROSSES THE AREA.

&&

.AVIATION...RAIN SHOWERS AND SOME THUNDERSTORMS WILL CONTINUE THIS
MORNING THROUGH LATE AFTERNOON...BEFORE DRYING OUT THIS EVENING.
LOCALIZED IFR CONDITIONS POSSIBLE IN AND AROUND THE HEAVIER
PRECIPITATION...OTHERWISE...MAINLY MVFR TO VFR CONDITIONS WILL
PREVAIL THROUGH EARLY EVENING.

&&

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

$$