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000
FXUS65 KCYS 020814
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
214 AM MDT SUN AUG 2 2015

.SHORT TERM...(TODAY THROUGH TUESDAY NIGHT)
ISSUED AT 300 AM MDT SUN AUG 2 2015

TODAY...FLOW ALOFT REMAINS NORTHWEST. LOOKS LIKE THE NAM PROJECTS A
LOW LEVEL BOUNDARY TO SET UP THIS AFTERNOON ALONG THE WYOMING AND
COLORADO STATE LINE WITH A NICE 850/700 MB THETA-E RIDGE AXIS OVER
NORTHERN COLORADO. THUS...AS NAM DEPICTS...EXPECT ISOLATED TO
SCATTERED THUNDERSTORMS TO DEVELOP ALONG AND NEAR THE COLORADO STATE
LINE...THEN SLOWLY DIMINISH THIS EVENING ALONG THE LARAMIE RANGE.

TONIGHT/MONDAY...MODELS CONSISTENT IN SHOWING MORE MONSOONAL
MOISTURE BEING TAPPED INTO AND MOVING ACROSS OUR COUNTIES MONDAY
AFTERNOON...THOUGH NOW FURTHER WEST THAN PREVIOUS RUNS INDICATED.
STILL THOUGH...WITH A SHORTWAVE TROUGH ALOFT MOVING OVERHEAD AND
INCREASING LOW AND MID LEVEL MOISTURE...WILL CONTINUE OUR FORECAST
WITH ISOLATED TO SCATTERED AFTERNOON AND EVENING THUNDERSTORMS ALONG
AND WEST OF INTERSTATE 25...WITH LESSER ACTIVITY FURTHER EAST.

MONDAY NIGHT/TUESDAY/TUESDAY NIGHT...SHORTWAVE TROUGH ALOFT MOVES
SLOWLY EASTWARD ACROSS OUR NORTHERN COUNTIES...AND WITH PLENTY OF
LOW AND MID LEVEL MOISTURE...WILL SEE SCATTERED SHOWERS AND
THUNDERSTORMS ACROSS OUR NORTHERN COUNTIES...LESS ACTIVITY FURTHER
SOUTH WITH DRIER AIRMASS AND NEGATIVE THETA-E ADVECTION.

.LONG TERM...(WEDNESDAY THROUGH SATURDAY)
ISSUED AT 300 AM MDT SUN AUG 2 2015

MONSOONAL MOISTURE TO REMAIN OVER THE AREA THROUGH AT LEAST
THURSDAY. DEPENDING ON WHICH MEDIUM RANGE GUIDANCE USED...IT COULD
BE LONGER. FORECAST BASED OFF THE MORE MOIST ECMWF THIS FORECAST
CYCLE.

STARTING OFF WEDNESDAY...WE ARE LOOKING AT THE SEMI-PERMANENT
THATS BEEN IN THE AREA TO LAY ALONG THE NEBRASKA
PANHANDLE...MAYBE SLIGHTLY FURTHER EAST. GFS SHOWING THE BOUNDARY
FURTHER EAST AND THUS THE ENTIRE CWFA DRY. ECMWF ON THE OTHER HAND
HAS THE BOUNDARY REMAINING ALONG THE EAST SLOPES OF THE LARAMIE
RANGE...WITH NORTHEAST UPSLOPE FLOW ACROSS THE PANHANDLE. THIS
WOULD GIVE MOST LOCATIONS ALONG AND EAST OF THE LARAMIE RANGE WITH
AT LEAST A SLIGHT CHANCE OF THUNDERSTORMS WEDNESDAY AFTERNOON.

THURSDAY AFTERNOON...A FAIRLY STRONG SHORTWAVE TRACKS ACROSS
NORTHERN WYOMING INTO SOUTH DAKOTA. STRONG SOUTH TO SOUTHEASTERLY
850MB WINDS IN THE PANHANDLE AND A 70KT 250MB JET COULD BE SETTING
US UP FOR ANOTHER ROUND OF SEVERE THUNDERSTORMS AT LEAST FOR THE
SOUTHERN HALF OF THE PANHANDLE AS WELL AS EASTERN LARAMIE
COUNTY...UP INTO GOSHEN COUNTY. SHOWERS AND THUNDERSTORMS LOOK TO
PERSIST INTO THE LATE EVENING HOURS THURSDAY.

AFTER A DRY FRIDAY WITH A TRANSITORY RIDGE MOVING THROUGH THE
CWFA...SATURDAY LOOKS TO BE A REPEAT OF THURSDAY AS ANOTHER
SHORTWAVE MOVES INTO THE AREA FROM THE SOUTHWEST. SHOULD SEE AT
LEAST SLIGHT CHANCE POPS FOR MUCH OF THE AREA WITH BEST CHANCES
ALONG THE WYOMING COLORADO STATE LINE.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1105 PM MDT SAT AUG 1 2015

BEST CHANCES FOR CONVECTION SHIFTS WEST INTO SOUTHEAST WYOMING
SUNDAY AFTERNOON AS AN UPPER DISTURBANCE APPROACHES FROM THE
WEST. LOOKS LIKE KLAR AND KCYS STAND THE BEST CHANCES FOR TSTMS
DURING THE AFTERNOON HOURS.

&&

.FIRE WEATHER...
ISSUED AT 145 AM MDT SUN AUG 2 2015

HUMIDITIES INCREASING THE NEXT FEW DAYS AS LOW AND
MID LEVEL MOISTURE INCREASES ALONG WITH INCREASING CHANCES FOR LATE
DAY SHOWERS AND THUNDERSTORMS.

&&

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

$$

SHORT TERM...RUBIN
LONG TERM...GCC
AVIATION...GCC
FIRE WEATHER...RUBIN



000
FXUS65 KCYS 020814
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
214 AM MDT SUN AUG 2 2015

.SHORT TERM...(TODAY THROUGH TUESDAY NIGHT)
ISSUED AT 300 AM MDT SUN AUG 2 2015

TODAY...FLOW ALOFT REMAINS NORTHWEST. LOOKS LIKE THE NAM PROJECTS A
LOW LEVEL BOUNDARY TO SET UP THIS AFTERNOON ALONG THE WYOMING AND
COLORADO STATE LINE WITH A NICE 850/700 MB THETA-E RIDGE AXIS OVER
NORTHERN COLORADO. THUS...AS NAM DEPICTS...EXPECT ISOLATED TO
SCATTERED THUNDERSTORMS TO DEVELOP ALONG AND NEAR THE COLORADO STATE
LINE...THEN SLOWLY DIMINISH THIS EVENING ALONG THE LARAMIE RANGE.

TONIGHT/MONDAY...MODELS CONSISTENT IN SHOWING MORE MONSOONAL
MOISTURE BEING TAPPED INTO AND MOVING ACROSS OUR COUNTIES MONDAY
AFTERNOON...THOUGH NOW FURTHER WEST THAN PREVIOUS RUNS INDICATED.
STILL THOUGH...WITH A SHORTWAVE TROUGH ALOFT MOVING OVERHEAD AND
INCREASING LOW AND MID LEVEL MOISTURE...WILL CONTINUE OUR FORECAST
WITH ISOLATED TO SCATTERED AFTERNOON AND EVENING THUNDERSTORMS ALONG
AND WEST OF INTERSTATE 25...WITH LESSER ACTIVITY FURTHER EAST.

MONDAY NIGHT/TUESDAY/TUESDAY NIGHT...SHORTWAVE TROUGH ALOFT MOVES
SLOWLY EASTWARD ACROSS OUR NORTHERN COUNTIES...AND WITH PLENTY OF
LOW AND MID LEVEL MOISTURE...WILL SEE SCATTERED SHOWERS AND
THUNDERSTORMS ACROSS OUR NORTHERN COUNTIES...LESS ACTIVITY FURTHER
SOUTH WITH DRIER AIRMASS AND NEGATIVE THETA-E ADVECTION.

.LONG TERM...(WEDNESDAY THROUGH SATURDAY)
ISSUED AT 300 AM MDT SUN AUG 2 2015

MONSOONAL MOISTURE TO REMAIN OVER THE AREA THROUGH AT LEAST
THURSDAY. DEPENDING ON WHICH MEDIUM RANGE GUIDANCE USED...IT COULD
BE LONGER. FORECAST BASED OFF THE MORE MOIST ECMWF THIS FORECAST
CYCLE.

STARTING OFF WEDNESDAY...WE ARE LOOKING AT THE SEMI-PERMANENT
THATS BEEN IN THE AREA TO LAY ALONG THE NEBRASKA
PANHANDLE...MAYBE SLIGHTLY FURTHER EAST. GFS SHOWING THE BOUNDARY
FURTHER EAST AND THUS THE ENTIRE CWFA DRY. ECMWF ON THE OTHER HAND
HAS THE BOUNDARY REMAINING ALONG THE EAST SLOPES OF THE LARAMIE
RANGE...WITH NORTHEAST UPSLOPE FLOW ACROSS THE PANHANDLE. THIS
WOULD GIVE MOST LOCATIONS ALONG AND EAST OF THE LARAMIE RANGE WITH
AT LEAST A SLIGHT CHANCE OF THUNDERSTORMS WEDNESDAY AFTERNOON.

THURSDAY AFTERNOON...A FAIRLY STRONG SHORTWAVE TRACKS ACROSS
NORTHERN WYOMING INTO SOUTH DAKOTA. STRONG SOUTH TO SOUTHEASTERLY
850MB WINDS IN THE PANHANDLE AND A 70KT 250MB JET COULD BE SETTING
US UP FOR ANOTHER ROUND OF SEVERE THUNDERSTORMS AT LEAST FOR THE
SOUTHERN HALF OF THE PANHANDLE AS WELL AS EASTERN LARAMIE
COUNTY...UP INTO GOSHEN COUNTY. SHOWERS AND THUNDERSTORMS LOOK TO
PERSIST INTO THE LATE EVENING HOURS THURSDAY.

AFTER A DRY FRIDAY WITH A TRANSITORY RIDGE MOVING THROUGH THE
CWFA...SATURDAY LOOKS TO BE A REPEAT OF THURSDAY AS ANOTHER
SHORTWAVE MOVES INTO THE AREA FROM THE SOUTHWEST. SHOULD SEE AT
LEAST SLIGHT CHANCE POPS FOR MUCH OF THE AREA WITH BEST CHANCES
ALONG THE WYOMING COLORADO STATE LINE.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1105 PM MDT SAT AUG 1 2015

BEST CHANCES FOR CONVECTION SHIFTS WEST INTO SOUTHEAST WYOMING
SUNDAY AFTERNOON AS AN UPPER DISTURBANCE APPROACHES FROM THE
WEST. LOOKS LIKE KLAR AND KCYS STAND THE BEST CHANCES FOR TSTMS
DURING THE AFTERNOON HOURS.

&&

.FIRE WEATHER...
ISSUED AT 145 AM MDT SUN AUG 2 2015

HUMIDITIES INCREASING THE NEXT FEW DAYS AS LOW AND
MID LEVEL MOISTURE INCREASES ALONG WITH INCREASING CHANCES FOR LATE
DAY SHOWERS AND THUNDERSTORMS.

&&

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

$$

SHORT TERM...RUBIN
LONG TERM...GCC
AVIATION...GCC
FIRE WEATHER...RUBIN



  [top]

000
FXUS65 KRIW 020544
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
1145 PM MDT SAT AUG 1 2015

UPDATE...ADDED 06Z AVIATION DISCUSSION.

.SHORT TERM...TONIGHT THROUGH SUNDAY (ISSUED AT 231 PM MDT)

WIDESPREAD HIGH PRESSURE EXPECTED TO CONTINUE ACROSS THE FORECAST
AREA. WARM TEMPERATURES WILL CONTINUE...ESPECIALLY ACROSS THE
NORTHERN BASINS WHERE VALUES WILL INCH CLOSER TOWARDS THE CENTURY
MARK.

CURRENT PATTERN REMAINS SUPPORTIVE OF LIGHT WIND THROUGH THE
FORECAST PERIOD AS WELL. A FEW HIGH CLOUDS COULD MOVE INTO THE
SOUTHERN PORTION OF THE FORECAST AREA SUNDAY AFTERNOON AS A WAVE
SLOWLY PROGRESSES TOWARDS THE STATE. MODELS CONTINUE TO SLOW THE
PROGRESS OF THIS WAVE. CURRENT PRECIPITATION FORECAST FOR SUNDAY
AFTERNOON MAY BE PESSIMISTIC BASED ON MOST RECENT MODEL
SOLUTIONS...BUT LEFT A FEW ISOLATED SHOWERS ACROSS THE
AREA...ESPECIALLY IN THE MID TO LATE AFTERNOON.

.LONG TERM...SUNDAY NIGHT THROUGH SATURDAY.

THE SHORTWAVE TROUGH FROM THE GREAT BASIN IS STILL EXPECTED TO MOVE
INTO WYOMING FROM SUNDAY NIGHT INTO MONDAY...ALTHOUGH ALL OF THE
MODELS SEEM TO HAVE SLOWED IT DOWN SOMEWHAT COMPARED TO YESTERDAYS
MODEL RUN.  THE RESULT WILL BE LESS OF A CHANCE OF PRECIPITATION
SUNDAY EVENING...WITH MORE OF A CONCENTRATION ON MONDAY...ESPECIALLY
DURING THE AFTERNOON AND EVENING HOURS.  SOUTHWEST WY WILL BE
IMPACTED FIRST...THEN THE REST OF CENTRAL AND SOUTHERN WY.  AT THIS
TIME EXPECTING GOOD MOISTURE AND MODERATE INSTABILITY TO BRING HEAVY
RAIN AND GUSTY OUTFLOW WIND WITH THE THUNDERSTORMS.  AS THE SYSTEM
PROGRESSES TO THE NORTHEAST...A BOUNDARY SHOULD DEVELOP ACROSS
CENTRAL WY WITH MOIST UNSTABLE AIR TO THE NORTH...AND DRIER WINDY
CONDITIONS TO THE SOUTH.  TUESDAY THEN WILL LIKELY SEE THE
CONVECTIVE ACTIVITY ACROSS NORTHERN WY.

ANOTHER WEAK SHORTWAVE TROUGH FROM THE PACIFIC THEN APPROACHES
WESTERN WY WED AFTERNOON AND EVENING...WITH THE GFS BEING THE
STRONGEST OF THE MEDIUM-RANGE MODELS.  HAVE GONE MORE OF A BLEND
WITH THE CHANCES OF PRECIPITATION...AND LIKE THE PREVIOUS
SHIFT...LEFT IN GUSTY WIND AS THE MAIN THREAT FROM THE
THUNDERSTORMS.  THE GENERAL PATTERN FROM MONDAY THROUGH WEDNESDAY
WILL KEEP TEMPERATURES NEAR OR BELOW NORMAL...WITH AN OBVIOUS
ENHANCEMENT FOR ABOVE NORMAL PRECIPITATION.

THURSDAY THROUGH SATURDAY LOOKS TO BE SLIGHTLY WARMER AND DRIER THAN
THE BEGINNING OF THE WEEK.  THURSDAY AFTERNOON AND EVENING SHOULD BE
FAIRLY DRY...EXCEPT FOR NE WY WITH SOME RESIDUAL INSTABILITY AND
MOISTURE FROM THE SHORTWAVE TROUGH.  BOTH THE GFS AND ECMWF INDICATE
ANOTHER SHORTWAVE TROUGH FROM THE PACIFIC MOVING INTO ID/MT/WY LATE
SATURDAY...AGAIN INCREASING THE CHANCE FOR SHOWERS AND
THUNDERSTORMS...BUT ALSO INCREASING THE WIND THROUGH CENTRAL AND
SOUTHERN WY.

&&

.AVIATION.../06Z ISSUANCE/

VFR CONDITIONS WITH MOSTLY UNLIMITED CIGS WILL PREVAIL THROUGH THE
PERIOD WITH GENERALLY LIGHT WIND LESS THAN 10KTS.  THE PREVAILING
SFC WIND WILL BECOME N-NE SUNDAY AFTERNOON.

AN UPPER LEVEL DISTURBANCE WILL LIFT NORTH ACROSS THE GREAT BASIN
SUNDAY NIGHT...SPREADING INCREASING MID-LEVEL MOISTURE...SCT-BKN
FL130-150...AND A FEW SHOWERS VCNTY AND SOUTH OF INTERSTATE 80 AFTER
06Z MONDAY.

&&

.FIRE WEATHER...

WARM AND DRY CONDITIONS WILL CONTINUE THROUGH SUNDAY MORNING...WITH
THE SLIGHT OPPORTUNITY FOR A FEW MOUNTAIN SHOWERS AND THUNDERSTORMS
SUNDAY AFTERNOON. AN APPROACHING WAVE FROM THE DESERT SOUTHWEST
CONTINUES TO LOOK LIKE THE NEXT WEATHER PRODUCING SYSTEM...THOUGH
MODELS CONTINUE TO DELAY ITS ARRIVAL INTO THE STATE. MONDAY
AFTERNOON NOW LOOKS FAIRLY FAVORABLE FOR SHOWERS AND THUNDERSTORMS
ASSOCIATED WITH THIS SYSTEM. MEANWHILE...THOUGH WARM AND DRY
CONDITIONS WILL PERSIST OTHERWISE WITH HUMIDITY IN THE LOW
TEENS...WINDS THROUGH MONDAY MORNING DO NOT LOOK SUPPORTIVE FOR
CRITICAL FIRE BEHAVIOR ACROSS THE AREA. WINDS DO GET STRONGER MONDAY
AFTERNOON...ESPECIALLY ACROSS SOUTHERN WYOMING. HOWEVER...MOST
LOCATIONS WHERE THE STRONGER WINDS ARE LOCATED WILL BE DEALING WITH
THE ARRIVAL OF THE AFOREMENTIONED WAVE OF LOW PRESSURE ELIMINATING
THE CONCERN FOR LOW HUMIDITY LEVELS.

&&

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

$$

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



000
FXUS65 KRIW 020544
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
1145 PM MDT SAT AUG 1 2015

UPDATE...ADDED 06Z AVIATION DISCUSSION.

.SHORT TERM...TONIGHT THROUGH SUNDAY (ISSUED AT 231 PM MDT)

WIDESPREAD HIGH PRESSURE EXPECTED TO CONTINUE ACROSS THE FORECAST
AREA. WARM TEMPERATURES WILL CONTINUE...ESPECIALLY ACROSS THE
NORTHERN BASINS WHERE VALUES WILL INCH CLOSER TOWARDS THE CENTURY
MARK.

CURRENT PATTERN REMAINS SUPPORTIVE OF LIGHT WIND THROUGH THE
FORECAST PERIOD AS WELL. A FEW HIGH CLOUDS COULD MOVE INTO THE
SOUTHERN PORTION OF THE FORECAST AREA SUNDAY AFTERNOON AS A WAVE
SLOWLY PROGRESSES TOWARDS THE STATE. MODELS CONTINUE TO SLOW THE
PROGRESS OF THIS WAVE. CURRENT PRECIPITATION FORECAST FOR SUNDAY
AFTERNOON MAY BE PESSIMISTIC BASED ON MOST RECENT MODEL
SOLUTIONS...BUT LEFT A FEW ISOLATED SHOWERS ACROSS THE
AREA...ESPECIALLY IN THE MID TO LATE AFTERNOON.

.LONG TERM...SUNDAY NIGHT THROUGH SATURDAY.

THE SHORTWAVE TROUGH FROM THE GREAT BASIN IS STILL EXPECTED TO MOVE
INTO WYOMING FROM SUNDAY NIGHT INTO MONDAY...ALTHOUGH ALL OF THE
MODELS SEEM TO HAVE SLOWED IT DOWN SOMEWHAT COMPARED TO YESTERDAYS
MODEL RUN.  THE RESULT WILL BE LESS OF A CHANCE OF PRECIPITATION
SUNDAY EVENING...WITH MORE OF A CONCENTRATION ON MONDAY...ESPECIALLY
DURING THE AFTERNOON AND EVENING HOURS.  SOUTHWEST WY WILL BE
IMPACTED FIRST...THEN THE REST OF CENTRAL AND SOUTHERN WY.  AT THIS
TIME EXPECTING GOOD MOISTURE AND MODERATE INSTABILITY TO BRING HEAVY
RAIN AND GUSTY OUTFLOW WIND WITH THE THUNDERSTORMS.  AS THE SYSTEM
PROGRESSES TO THE NORTHEAST...A BOUNDARY SHOULD DEVELOP ACROSS
CENTRAL WY WITH MOIST UNSTABLE AIR TO THE NORTH...AND DRIER WINDY
CONDITIONS TO THE SOUTH.  TUESDAY THEN WILL LIKELY SEE THE
CONVECTIVE ACTIVITY ACROSS NORTHERN WY.

ANOTHER WEAK SHORTWAVE TROUGH FROM THE PACIFIC THEN APPROACHES
WESTERN WY WED AFTERNOON AND EVENING...WITH THE GFS BEING THE
STRONGEST OF THE MEDIUM-RANGE MODELS.  HAVE GONE MORE OF A BLEND
WITH THE CHANCES OF PRECIPITATION...AND LIKE THE PREVIOUS
SHIFT...LEFT IN GUSTY WIND AS THE MAIN THREAT FROM THE
THUNDERSTORMS.  THE GENERAL PATTERN FROM MONDAY THROUGH WEDNESDAY
WILL KEEP TEMPERATURES NEAR OR BELOW NORMAL...WITH AN OBVIOUS
ENHANCEMENT FOR ABOVE NORMAL PRECIPITATION.

THURSDAY THROUGH SATURDAY LOOKS TO BE SLIGHTLY WARMER AND DRIER THAN
THE BEGINNING OF THE WEEK.  THURSDAY AFTERNOON AND EVENING SHOULD BE
FAIRLY DRY...EXCEPT FOR NE WY WITH SOME RESIDUAL INSTABILITY AND
MOISTURE FROM THE SHORTWAVE TROUGH.  BOTH THE GFS AND ECMWF INDICATE
ANOTHER SHORTWAVE TROUGH FROM THE PACIFIC MOVING INTO ID/MT/WY LATE
SATURDAY...AGAIN INCREASING THE CHANCE FOR SHOWERS AND
THUNDERSTORMS...BUT ALSO INCREASING THE WIND THROUGH CENTRAL AND
SOUTHERN WY.

&&

.AVIATION.../06Z ISSUANCE/

VFR CONDITIONS WITH MOSTLY UNLIMITED CIGS WILL PREVAIL THROUGH THE
PERIOD WITH GENERALLY LIGHT WIND LESS THAN 10KTS.  THE PREVAILING
SFC WIND WILL BECOME N-NE SUNDAY AFTERNOON.

AN UPPER LEVEL DISTURBANCE WILL LIFT NORTH ACROSS THE GREAT BASIN
SUNDAY NIGHT...SPREADING INCREASING MID-LEVEL MOISTURE...SCT-BKN
FL130-150...AND A FEW SHOWERS VCNTY AND SOUTH OF INTERSTATE 80 AFTER
06Z MONDAY.

&&

.FIRE WEATHER...

WARM AND DRY CONDITIONS WILL CONTINUE THROUGH SUNDAY MORNING...WITH
THE SLIGHT OPPORTUNITY FOR A FEW MOUNTAIN SHOWERS AND THUNDERSTORMS
SUNDAY AFTERNOON. AN APPROACHING WAVE FROM THE DESERT SOUTHWEST
CONTINUES TO LOOK LIKE THE NEXT WEATHER PRODUCING SYSTEM...THOUGH
MODELS CONTINUE TO DELAY ITS ARRIVAL INTO THE STATE. MONDAY
AFTERNOON NOW LOOKS FAIRLY FAVORABLE FOR SHOWERS AND THUNDERSTORMS
ASSOCIATED WITH THIS SYSTEM. MEANWHILE...THOUGH WARM AND DRY
CONDITIONS WILL PERSIST OTHERWISE WITH HUMIDITY IN THE LOW
TEENS...WINDS THROUGH MONDAY MORNING DO NOT LOOK SUPPORTIVE FOR
CRITICAL FIRE BEHAVIOR ACROSS THE AREA. WINDS DO GET STRONGER MONDAY
AFTERNOON...ESPECIALLY ACROSS SOUTHERN WYOMING. HOWEVER...MOST
LOCATIONS WHERE THE STRONGER WINDS ARE LOCATED WILL BE DEALING WITH
THE ARRIVAL OF THE AFOREMENTIONED WAVE OF LOW PRESSURE ELIMINATING
THE CONCERN FOR LOW HUMIDITY LEVELS.

&&

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

$$

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



000
FXUS65 KRIW 020544
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
1145 PM MDT SAT AUG 1 2015

UPDATE...ADDED 06Z AVIATION DISCUSSION.

.SHORT TERM...TONIGHT THROUGH SUNDAY (ISSUED AT 231 PM MDT)

WIDESPREAD HIGH PRESSURE EXPECTED TO CONTINUE ACROSS THE FORECAST
AREA. WARM TEMPERATURES WILL CONTINUE...ESPECIALLY ACROSS THE
NORTHERN BASINS WHERE VALUES WILL INCH CLOSER TOWARDS THE CENTURY
MARK.

CURRENT PATTERN REMAINS SUPPORTIVE OF LIGHT WIND THROUGH THE
FORECAST PERIOD AS WELL. A FEW HIGH CLOUDS COULD MOVE INTO THE
SOUTHERN PORTION OF THE FORECAST AREA SUNDAY AFTERNOON AS A WAVE
SLOWLY PROGRESSES TOWARDS THE STATE. MODELS CONTINUE TO SLOW THE
PROGRESS OF THIS WAVE. CURRENT PRECIPITATION FORECAST FOR SUNDAY
AFTERNOON MAY BE PESSIMISTIC BASED ON MOST RECENT MODEL
SOLUTIONS...BUT LEFT A FEW ISOLATED SHOWERS ACROSS THE
AREA...ESPECIALLY IN THE MID TO LATE AFTERNOON.

.LONG TERM...SUNDAY NIGHT THROUGH SATURDAY.

THE SHORTWAVE TROUGH FROM THE GREAT BASIN IS STILL EXPECTED TO MOVE
INTO WYOMING FROM SUNDAY NIGHT INTO MONDAY...ALTHOUGH ALL OF THE
MODELS SEEM TO HAVE SLOWED IT DOWN SOMEWHAT COMPARED TO YESTERDAYS
MODEL RUN.  THE RESULT WILL BE LESS OF A CHANCE OF PRECIPITATION
SUNDAY EVENING...WITH MORE OF A CONCENTRATION ON MONDAY...ESPECIALLY
DURING THE AFTERNOON AND EVENING HOURS.  SOUTHWEST WY WILL BE
IMPACTED FIRST...THEN THE REST OF CENTRAL AND SOUTHERN WY.  AT THIS
TIME EXPECTING GOOD MOISTURE AND MODERATE INSTABILITY TO BRING HEAVY
RAIN AND GUSTY OUTFLOW WIND WITH THE THUNDERSTORMS.  AS THE SYSTEM
PROGRESSES TO THE NORTHEAST...A BOUNDARY SHOULD DEVELOP ACROSS
CENTRAL WY WITH MOIST UNSTABLE AIR TO THE NORTH...AND DRIER WINDY
CONDITIONS TO THE SOUTH.  TUESDAY THEN WILL LIKELY SEE THE
CONVECTIVE ACTIVITY ACROSS NORTHERN WY.

ANOTHER WEAK SHORTWAVE TROUGH FROM THE PACIFIC THEN APPROACHES
WESTERN WY WED AFTERNOON AND EVENING...WITH THE GFS BEING THE
STRONGEST OF THE MEDIUM-RANGE MODELS.  HAVE GONE MORE OF A BLEND
WITH THE CHANCES OF PRECIPITATION...AND LIKE THE PREVIOUS
SHIFT...LEFT IN GUSTY WIND AS THE MAIN THREAT FROM THE
THUNDERSTORMS.  THE GENERAL PATTERN FROM MONDAY THROUGH WEDNESDAY
WILL KEEP TEMPERATURES NEAR OR BELOW NORMAL...WITH AN OBVIOUS
ENHANCEMENT FOR ABOVE NORMAL PRECIPITATION.

THURSDAY THROUGH SATURDAY LOOKS TO BE SLIGHTLY WARMER AND DRIER THAN
THE BEGINNING OF THE WEEK.  THURSDAY AFTERNOON AND EVENING SHOULD BE
FAIRLY DRY...EXCEPT FOR NE WY WITH SOME RESIDUAL INSTABILITY AND
MOISTURE FROM THE SHORTWAVE TROUGH.  BOTH THE GFS AND ECMWF INDICATE
ANOTHER SHORTWAVE TROUGH FROM THE PACIFIC MOVING INTO ID/MT/WY LATE
SATURDAY...AGAIN INCREASING THE CHANCE FOR SHOWERS AND
THUNDERSTORMS...BUT ALSO INCREASING THE WIND THROUGH CENTRAL AND
SOUTHERN WY.

&&

.AVIATION.../06Z ISSUANCE/

VFR CONDITIONS WITH MOSTLY UNLIMITED CIGS WILL PREVAIL THROUGH THE
PERIOD WITH GENERALLY LIGHT WIND LESS THAN 10KTS.  THE PREVAILING
SFC WIND WILL BECOME N-NE SUNDAY AFTERNOON.

AN UPPER LEVEL DISTURBANCE WILL LIFT NORTH ACROSS THE GREAT BASIN
SUNDAY NIGHT...SPREADING INCREASING MID-LEVEL MOISTURE...SCT-BKN
FL130-150...AND A FEW SHOWERS VCNTY AND SOUTH OF INTERSTATE 80 AFTER
06Z MONDAY.

&&

.FIRE WEATHER...

WARM AND DRY CONDITIONS WILL CONTINUE THROUGH SUNDAY MORNING...WITH
THE SLIGHT OPPORTUNITY FOR A FEW MOUNTAIN SHOWERS AND THUNDERSTORMS
SUNDAY AFTERNOON. AN APPROACHING WAVE FROM THE DESERT SOUTHWEST
CONTINUES TO LOOK LIKE THE NEXT WEATHER PRODUCING SYSTEM...THOUGH
MODELS CONTINUE TO DELAY ITS ARRIVAL INTO THE STATE. MONDAY
AFTERNOON NOW LOOKS FAIRLY FAVORABLE FOR SHOWERS AND THUNDERSTORMS
ASSOCIATED WITH THIS SYSTEM. MEANWHILE...THOUGH WARM AND DRY
CONDITIONS WILL PERSIST OTHERWISE WITH HUMIDITY IN THE LOW
TEENS...WINDS THROUGH MONDAY MORNING DO NOT LOOK SUPPORTIVE FOR
CRITICAL FIRE BEHAVIOR ACROSS THE AREA. WINDS DO GET STRONGER MONDAY
AFTERNOON...ESPECIALLY ACROSS SOUTHERN WYOMING. HOWEVER...MOST
LOCATIONS WHERE THE STRONGER WINDS ARE LOCATED WILL BE DEALING WITH
THE ARRIVAL OF THE AFOREMENTIONED WAVE OF LOW PRESSURE ELIMINATING
THE CONCERN FOR LOW HUMIDITY LEVELS.

&&

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

$$

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



000
FXUS65 KRIW 020544
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
1145 PM MDT SAT AUG 1 2015

UPDATE...ADDED 06Z AVIATION DISCUSSION.

.SHORT TERM...TONIGHT THROUGH SUNDAY (ISSUED AT 231 PM MDT)

WIDESPREAD HIGH PRESSURE EXPECTED TO CONTINUE ACROSS THE FORECAST
AREA. WARM TEMPERATURES WILL CONTINUE...ESPECIALLY ACROSS THE
NORTHERN BASINS WHERE VALUES WILL INCH CLOSER TOWARDS THE CENTURY
MARK.

CURRENT PATTERN REMAINS SUPPORTIVE OF LIGHT WIND THROUGH THE
FORECAST PERIOD AS WELL. A FEW HIGH CLOUDS COULD MOVE INTO THE
SOUTHERN PORTION OF THE FORECAST AREA SUNDAY AFTERNOON AS A WAVE
SLOWLY PROGRESSES TOWARDS THE STATE. MODELS CONTINUE TO SLOW THE
PROGRESS OF THIS WAVE. CURRENT PRECIPITATION FORECAST FOR SUNDAY
AFTERNOON MAY BE PESSIMISTIC BASED ON MOST RECENT MODEL
SOLUTIONS...BUT LEFT A FEW ISOLATED SHOWERS ACROSS THE
AREA...ESPECIALLY IN THE MID TO LATE AFTERNOON.

.LONG TERM...SUNDAY NIGHT THROUGH SATURDAY.

THE SHORTWAVE TROUGH FROM THE GREAT BASIN IS STILL EXPECTED TO MOVE
INTO WYOMING FROM SUNDAY NIGHT INTO MONDAY...ALTHOUGH ALL OF THE
MODELS SEEM TO HAVE SLOWED IT DOWN SOMEWHAT COMPARED TO YESTERDAYS
MODEL RUN.  THE RESULT WILL BE LESS OF A CHANCE OF PRECIPITATION
SUNDAY EVENING...WITH MORE OF A CONCENTRATION ON MONDAY...ESPECIALLY
DURING THE AFTERNOON AND EVENING HOURS.  SOUTHWEST WY WILL BE
IMPACTED FIRST...THEN THE REST OF CENTRAL AND SOUTHERN WY.  AT THIS
TIME EXPECTING GOOD MOISTURE AND MODERATE INSTABILITY TO BRING HEAVY
RAIN AND GUSTY OUTFLOW WIND WITH THE THUNDERSTORMS.  AS THE SYSTEM
PROGRESSES TO THE NORTHEAST...A BOUNDARY SHOULD DEVELOP ACROSS
CENTRAL WY WITH MOIST UNSTABLE AIR TO THE NORTH...AND DRIER WINDY
CONDITIONS TO THE SOUTH.  TUESDAY THEN WILL LIKELY SEE THE
CONVECTIVE ACTIVITY ACROSS NORTHERN WY.

ANOTHER WEAK SHORTWAVE TROUGH FROM THE PACIFIC THEN APPROACHES
WESTERN WY WED AFTERNOON AND EVENING...WITH THE GFS BEING THE
STRONGEST OF THE MEDIUM-RANGE MODELS.  HAVE GONE MORE OF A BLEND
WITH THE CHANCES OF PRECIPITATION...AND LIKE THE PREVIOUS
SHIFT...LEFT IN GUSTY WIND AS THE MAIN THREAT FROM THE
THUNDERSTORMS.  THE GENERAL PATTERN FROM MONDAY THROUGH WEDNESDAY
WILL KEEP TEMPERATURES NEAR OR BELOW NORMAL...WITH AN OBVIOUS
ENHANCEMENT FOR ABOVE NORMAL PRECIPITATION.

THURSDAY THROUGH SATURDAY LOOKS TO BE SLIGHTLY WARMER AND DRIER THAN
THE BEGINNING OF THE WEEK.  THURSDAY AFTERNOON AND EVENING SHOULD BE
FAIRLY DRY...EXCEPT FOR NE WY WITH SOME RESIDUAL INSTABILITY AND
MOISTURE FROM THE SHORTWAVE TROUGH.  BOTH THE GFS AND ECMWF INDICATE
ANOTHER SHORTWAVE TROUGH FROM THE PACIFIC MOVING INTO ID/MT/WY LATE
SATURDAY...AGAIN INCREASING THE CHANCE FOR SHOWERS AND
THUNDERSTORMS...BUT ALSO INCREASING THE WIND THROUGH CENTRAL AND
SOUTHERN WY.

&&

.AVIATION.../06Z ISSUANCE/

VFR CONDITIONS WITH MOSTLY UNLIMITED CIGS WILL PREVAIL THROUGH THE
PERIOD WITH GENERALLY LIGHT WIND LESS THAN 10KTS.  THE PREVAILING
SFC WIND WILL BECOME N-NE SUNDAY AFTERNOON.

AN UPPER LEVEL DISTURBANCE WILL LIFT NORTH ACROSS THE GREAT BASIN
SUNDAY NIGHT...SPREADING INCREASING MID-LEVEL MOISTURE...SCT-BKN
FL130-150...AND A FEW SHOWERS VCNTY AND SOUTH OF INTERSTATE 80 AFTER
06Z MONDAY.

&&

.FIRE WEATHER...

WARM AND DRY CONDITIONS WILL CONTINUE THROUGH SUNDAY MORNING...WITH
THE SLIGHT OPPORTUNITY FOR A FEW MOUNTAIN SHOWERS AND THUNDERSTORMS
SUNDAY AFTERNOON. AN APPROACHING WAVE FROM THE DESERT SOUTHWEST
CONTINUES TO LOOK LIKE THE NEXT WEATHER PRODUCING SYSTEM...THOUGH
MODELS CONTINUE TO DELAY ITS ARRIVAL INTO THE STATE. MONDAY
AFTERNOON NOW LOOKS FAIRLY FAVORABLE FOR SHOWERS AND THUNDERSTORMS
ASSOCIATED WITH THIS SYSTEM. MEANWHILE...THOUGH WARM AND DRY
CONDITIONS WILL PERSIST OTHERWISE WITH HUMIDITY IN THE LOW
TEENS...WINDS THROUGH MONDAY MORNING DO NOT LOOK SUPPORTIVE FOR
CRITICAL FIRE BEHAVIOR ACROSS THE AREA. WINDS DO GET STRONGER MONDAY
AFTERNOON...ESPECIALLY ACROSS SOUTHERN WYOMING. HOWEVER...MOST
LOCATIONS WHERE THE STRONGER WINDS ARE LOCATED WILL BE DEALING WITH
THE ARRIVAL OF THE AFOREMENTIONED WAVE OF LOW PRESSURE ELIMINATING
THE CONCERN FOR LOW HUMIDITY LEVELS.

&&

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

$$

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



000
FXUS65 KCYS 020507
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
1107 PM MDT SAT AUG 1 2015

.SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT)
ISSUED AT 344 PM MDT SAT AUG 1 2015

CONVECTION HAS DEVELOPED THIS AFTERNOON OFF THE HIGHER TERRAIN...IN
ADDITION TO THE SURFACE TROUGH THAT IS SITUATED ROUGHLY NEAR
CHEYENNE TO CHADRON NEBRASKA. MODERATE INSTABILITY IS IN PLACE
EAST OF THIS AREA WITH DEW POINTS IN THE LOW 50S TO LOW 60S UNDER
FAIRLY STEEP LAPSE RATES. ONE STORM IN SOUTHERN SIOUX COUNTY
PULSED VIGOROUSLY AT TIMES EARLIER THIS AFTERNOON...AND WOULD
EXPECT THIS TO BE THE TREND THROUGH THE REST OF THE AFTERNOON WITH
CONVECTION EAST OF THIS BOUNDARY. DEEP LAYER SHEAR ANALYSIS SHOWS
ROUGHLY 30-40 KTS IN PLACE...SO SOME ORGANIZATION OF CONVECTION IS
POSSIBLE BUT THE MAJORITY OF STORMS WILL REMAIN STRONG IN NATURE
WITH SOME HAIL...GUSTY WINDS AND MODERATE RAINFALL POSSIBLE OUT OF
THE STRONGER ACTIVITY. A WEAK WAVE APPROACHING FROM THE NORTHWEST
COULD KEEP A FEW STORMS GOING THROUGH SUNSET ALONG AND EAST OF THE
LARAMIE RANGE...ESPECIALLY IN AREAS OF OUTFLOW BOUNDARY
INTERACTION SO KEPT ISOLATED POPS FOR THESE AREAS THRU 03Z.
OTHERWISE TONIGHT SHOULD REMAIN DRY AND MILD.

THE SFC BOUNDARY WILL PUSH EAST TONIGHT AS THE WAVE MOVES
OVERHEAD...BUT YET ANOTHER SFC FRONT WILL DROP SOUTH ACROSS THE
PLAINS SUNDAY AFTERNOON. AT THE SAME TIME...A STRONGER SHORTWAVE
APPROACHING FROM THE SOUTHWEST WILL INDUCE STRONGER EAST-
SOUTHEASTERLY WINDS AT THE SFC AND LOW LEVEL MOISTURE ADVECTION
THROUGH THE DAY. THUS...WE ARE ONCE AGAIN EXPECTING ISOLATED
SHOWERS AND THUNDERSTORMS IN THE AFTERNOON FOR THE MOUNTAINS AND
THE WYOMING PLAINS AS THE FRONT PUSHES THROUGH AND WAVE APPROACHES
FROM THE SOUTHWEST. THAT SHORTWAVE WILL MOVE OVERHEAD ON
MONDAY...BRINGING WITH IT A MARKED INCREASE IN MONSOONAL MOISTURE.
PERHAPS WILL SEE SHOWERS/STORMS INITIATE EARLIER IN THE DAY AND
WITH A BROADER COVERAGE OF ACTIVITY ACROSS THE CWA. LOOKING AT
MODERATE TO HEAVY RAINFALL RATES FROM THIS ACTIVITY. WITH THE VERY
DRY ANTECEDENT CONDITIONS WEST OF THE LARAMIE RANGE AND ACROSS
CONVERSE/NIOBRARA COUNTIES...NOT ANTICIPATING ANY SIGNIFICANT
FLOODING ISSUES HERE. AREAS FURTHER SOUTH AND EAST...WILL HAVE TO
WATCH FOR THE POSSIBILITY OF FLASH FLOODING IN AREAS THAT SEE
HEAVIER RAINFALL OVER THE NEXT COUPLE OF DAYS WHICH COULD SATURATE
SOILS.

.LONG TERM...(TUESDAY THROUGH SATURDAY)
ISSUED AT 344 PM MDT SAT AUG 1 2015

MODELS ARE IN A LITTLE BETTER AGREEMENT TODAY IN THE LONG
TERM...BUT STILL STRUGGLING WITH THE TIMING OF SHORT WAVE ENERGY
EMBEDDED IN THE WEST TO NORTHWEST FLOW ALOFT. ALL MODELS NOW
INDICATE A FLATTER RIDGE COMPARED TO THE LAST FEW DAYS...WITH
WEAK SHORTWAVE DISTURBANCES MOVING ACROSS THE AREA. TUESDAY
APPEARS TO BE FAVORABLE FOR SCATTERED COVERAGE OF SHOWERS AND
TSTORMS THROUGH THE AFTERNOON OVER THE HIGH PLAINS...SO KEPT POP
ON THE HIGH SIDE ALONG AND EAST OF I25. THE GFS AND ECMWF SHOW A
PAIR OF STRONGER DISTURBANCES ON WEDNESDAY AND THURSDAY...AS A
COOL FRONT ACCELERATES SOUTHWARD ACROSS THE HIGH PLAINS BRINGING
COOLER TEMPERATURES TO THE REGION. KEPT POP LOW DURING THE
WEDNESDAY- THURSDAY TIME PERIOD BECAUSE OF THE TIMING OF THE FRONT
AND ASSOCIATED DISTURBANCE ALOFT...WHICH ALL MODELS SHOW MOVING
EAST OF THE FORECAST AREA BY THE AFTERNOON. THIS WOULD PUT MOST OF
SOUTHEAST WYOMING UNDER THE MID LEVEL SUBSIDENCE REGION BEHIND
THE TROUGH AXIS...WHICH IS NOT FAVORABLE FOR WIDESPREAD
CONVECTION. HOWEVER...THIS MAY CHANGE IN THE NEAR FUTURE IF MODEL
SOLUTIONS TREND A BIT MORE PROGRESSIVE. THE GFS AND ECMWF
SOLUTIONS ARE SIMILAR DURING THE MIDDLE OF THE WEEK...BUT THE
ECMWF IS FAR MORE WET...SHOWING LARGE AMOUNTS OF QPF EAST OF I25.

FOR LATE IN THE WEEK AND EARLY NEXT WEEKEND...MODELS ARE IN
REASONABLE AGREEMENT SHOWING AN UPPER LEVEL RIDGE AXIS MOVING
ACROSS THE FRONT RANGE...EXTENDING FROM COLORADO NORTHWARD INTO
SOUTHERN CANADA. ONCE THIS RIDGE AXIS PUSHES A BIT FURTHER
EAST...EXPECT A GREATER COVERAGE OF THUNDERSTORMS BY NEXT WEEKEND
AS SOME MONSOON MOISTURE BEGINS TO ADVECT NORTHWARD.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1105 PM MDT SAT AUG 1 2015

BEST CHANCES FOR CONVECTION SHIFTS WEST INTO SOUTHEAST WYOMING
SUNDAY AFTERNOON AS AN UPPER DISTURBANCE APPROACHES FROM THE
WEST. LOOKS LIKE KLAR AND KCYS STAND THE BEST CHANCES FOR TSTMS
DURING THE AFTERNOON HOURS.

&&

.FIRE WEATHER...
ISSUED AT 344 PM MDT SAT AUG 1 2015

HUMIDITIES HAVE DROPPED INTO THE LOW TO MID TEENS THIS AFTERNOON
WEST OF A LINE FROM CHEYENNE- CHADRON. A FEW GUSTS AROUND 20 MPH
ARE OCCURRING ACROSS THIS AREA AS WELL...WITH THE STRONGEST WINDS
IN THE NORTH SNOWY RANGE FOOTHILLS. ISOLATED SHOWERS AND
THUNDERSTORMS DEVELOPED OVER THE HIGH COUNTRY AND ALONG THIS
BOUNDARY...WITH LIGHT RAINFALL LIKELY IN THE MOUNTAINS AND MORE
MODERATE RAINFALL RATES ACROSS THE PLAINS. MONSOONAL MOISTURE WILL
MOVE IN FOR MONDAY AND TUESDAY WITH HIGHER HUMIDITIES AND
INCREASED CHANCES FOR AFTERNOON AND EVENING THUNDERSTORMS. WARMER
AND DRIER WEATHER WILL PREVAIL FOR WEDNESDAY THROUGH FRIDAY.

&&

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

$$

SHORT TERM...RJM
LONG TERM...TJT
AVIATION...GCC
FIRE WEATHER...RJM



000
FXUS65 KCYS 020507
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
1107 PM MDT SAT AUG 1 2015

.SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT)
ISSUED AT 344 PM MDT SAT AUG 1 2015

CONVECTION HAS DEVELOPED THIS AFTERNOON OFF THE HIGHER TERRAIN...IN
ADDITION TO THE SURFACE TROUGH THAT IS SITUATED ROUGHLY NEAR
CHEYENNE TO CHADRON NEBRASKA. MODERATE INSTABILITY IS IN PLACE
EAST OF THIS AREA WITH DEW POINTS IN THE LOW 50S TO LOW 60S UNDER
FAIRLY STEEP LAPSE RATES. ONE STORM IN SOUTHERN SIOUX COUNTY
PULSED VIGOROUSLY AT TIMES EARLIER THIS AFTERNOON...AND WOULD
EXPECT THIS TO BE THE TREND THROUGH THE REST OF THE AFTERNOON WITH
CONVECTION EAST OF THIS BOUNDARY. DEEP LAYER SHEAR ANALYSIS SHOWS
ROUGHLY 30-40 KTS IN PLACE...SO SOME ORGANIZATION OF CONVECTION IS
POSSIBLE BUT THE MAJORITY OF STORMS WILL REMAIN STRONG IN NATURE
WITH SOME HAIL...GUSTY WINDS AND MODERATE RAINFALL POSSIBLE OUT OF
THE STRONGER ACTIVITY. A WEAK WAVE APPROACHING FROM THE NORTHWEST
COULD KEEP A FEW STORMS GOING THROUGH SUNSET ALONG AND EAST OF THE
LARAMIE RANGE...ESPECIALLY IN AREAS OF OUTFLOW BOUNDARY
INTERACTION SO KEPT ISOLATED POPS FOR THESE AREAS THRU 03Z.
OTHERWISE TONIGHT SHOULD REMAIN DRY AND MILD.

THE SFC BOUNDARY WILL PUSH EAST TONIGHT AS THE WAVE MOVES
OVERHEAD...BUT YET ANOTHER SFC FRONT WILL DROP SOUTH ACROSS THE
PLAINS SUNDAY AFTERNOON. AT THE SAME TIME...A STRONGER SHORTWAVE
APPROACHING FROM THE SOUTHWEST WILL INDUCE STRONGER EAST-
SOUTHEASTERLY WINDS AT THE SFC AND LOW LEVEL MOISTURE ADVECTION
THROUGH THE DAY. THUS...WE ARE ONCE AGAIN EXPECTING ISOLATED
SHOWERS AND THUNDERSTORMS IN THE AFTERNOON FOR THE MOUNTAINS AND
THE WYOMING PLAINS AS THE FRONT PUSHES THROUGH AND WAVE APPROACHES
FROM THE SOUTHWEST. THAT SHORTWAVE WILL MOVE OVERHEAD ON
MONDAY...BRINGING WITH IT A MARKED INCREASE IN MONSOONAL MOISTURE.
PERHAPS WILL SEE SHOWERS/STORMS INITIATE EARLIER IN THE DAY AND
WITH A BROADER COVERAGE OF ACTIVITY ACROSS THE CWA. LOOKING AT
MODERATE TO HEAVY RAINFALL RATES FROM THIS ACTIVITY. WITH THE VERY
DRY ANTECEDENT CONDITIONS WEST OF THE LARAMIE RANGE AND ACROSS
CONVERSE/NIOBRARA COUNTIES...NOT ANTICIPATING ANY SIGNIFICANT
FLOODING ISSUES HERE. AREAS FURTHER SOUTH AND EAST...WILL HAVE TO
WATCH FOR THE POSSIBILITY OF FLASH FLOODING IN AREAS THAT SEE
HEAVIER RAINFALL OVER THE NEXT COUPLE OF DAYS WHICH COULD SATURATE
SOILS.

.LONG TERM...(TUESDAY THROUGH SATURDAY)
ISSUED AT 344 PM MDT SAT AUG 1 2015

MODELS ARE IN A LITTLE BETTER AGREEMENT TODAY IN THE LONG
TERM...BUT STILL STRUGGLING WITH THE TIMING OF SHORT WAVE ENERGY
EMBEDDED IN THE WEST TO NORTHWEST FLOW ALOFT. ALL MODELS NOW
INDICATE A FLATTER RIDGE COMPARED TO THE LAST FEW DAYS...WITH
WEAK SHORTWAVE DISTURBANCES MOVING ACROSS THE AREA. TUESDAY
APPEARS TO BE FAVORABLE FOR SCATTERED COVERAGE OF SHOWERS AND
TSTORMS THROUGH THE AFTERNOON OVER THE HIGH PLAINS...SO KEPT POP
ON THE HIGH SIDE ALONG AND EAST OF I25. THE GFS AND ECMWF SHOW A
PAIR OF STRONGER DISTURBANCES ON WEDNESDAY AND THURSDAY...AS A
COOL FRONT ACCELERATES SOUTHWARD ACROSS THE HIGH PLAINS BRINGING
COOLER TEMPERATURES TO THE REGION. KEPT POP LOW DURING THE
WEDNESDAY- THURSDAY TIME PERIOD BECAUSE OF THE TIMING OF THE FRONT
AND ASSOCIATED DISTURBANCE ALOFT...WHICH ALL MODELS SHOW MOVING
EAST OF THE FORECAST AREA BY THE AFTERNOON. THIS WOULD PUT MOST OF
SOUTHEAST WYOMING UNDER THE MID LEVEL SUBSIDENCE REGION BEHIND
THE TROUGH AXIS...WHICH IS NOT FAVORABLE FOR WIDESPREAD
CONVECTION. HOWEVER...THIS MAY CHANGE IN THE NEAR FUTURE IF MODEL
SOLUTIONS TREND A BIT MORE PROGRESSIVE. THE GFS AND ECMWF
SOLUTIONS ARE SIMILAR DURING THE MIDDLE OF THE WEEK...BUT THE
ECMWF IS FAR MORE WET...SHOWING LARGE AMOUNTS OF QPF EAST OF I25.

FOR LATE IN THE WEEK AND EARLY NEXT WEEKEND...MODELS ARE IN
REASONABLE AGREEMENT SHOWING AN UPPER LEVEL RIDGE AXIS MOVING
ACROSS THE FRONT RANGE...EXTENDING FROM COLORADO NORTHWARD INTO
SOUTHERN CANADA. ONCE THIS RIDGE AXIS PUSHES A BIT FURTHER
EAST...EXPECT A GREATER COVERAGE OF THUNDERSTORMS BY NEXT WEEKEND
AS SOME MONSOON MOISTURE BEGINS TO ADVECT NORTHWARD.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1105 PM MDT SAT AUG 1 2015

BEST CHANCES FOR CONVECTION SHIFTS WEST INTO SOUTHEAST WYOMING
SUNDAY AFTERNOON AS AN UPPER DISTURBANCE APPROACHES FROM THE
WEST. LOOKS LIKE KLAR AND KCYS STAND THE BEST CHANCES FOR TSTMS
DURING THE AFTERNOON HOURS.

&&

.FIRE WEATHER...
ISSUED AT 344 PM MDT SAT AUG 1 2015

HUMIDITIES HAVE DROPPED INTO THE LOW TO MID TEENS THIS AFTERNOON
WEST OF A LINE FROM CHEYENNE- CHADRON. A FEW GUSTS AROUND 20 MPH
ARE OCCURRING ACROSS THIS AREA AS WELL...WITH THE STRONGEST WINDS
IN THE NORTH SNOWY RANGE FOOTHILLS. ISOLATED SHOWERS AND
THUNDERSTORMS DEVELOPED OVER THE HIGH COUNTRY AND ALONG THIS
BOUNDARY...WITH LIGHT RAINFALL LIKELY IN THE MOUNTAINS AND MORE
MODERATE RAINFALL RATES ACROSS THE PLAINS. MONSOONAL MOISTURE WILL
MOVE IN FOR MONDAY AND TUESDAY WITH HIGHER HUMIDITIES AND
INCREASED CHANCES FOR AFTERNOON AND EVENING THUNDERSTORMS. WARMER
AND DRIER WEATHER WILL PREVAIL FOR WEDNESDAY THROUGH FRIDAY.

&&

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

$$

SHORT TERM...RJM
LONG TERM...TJT
AVIATION...GCC
FIRE WEATHER...RJM



000
FXUS65 KCYS 020507
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
1107 PM MDT SAT AUG 1 2015

.SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT)
ISSUED AT 344 PM MDT SAT AUG 1 2015

CONVECTION HAS DEVELOPED THIS AFTERNOON OFF THE HIGHER TERRAIN...IN
ADDITION TO THE SURFACE TROUGH THAT IS SITUATED ROUGHLY NEAR
CHEYENNE TO CHADRON NEBRASKA. MODERATE INSTABILITY IS IN PLACE
EAST OF THIS AREA WITH DEW POINTS IN THE LOW 50S TO LOW 60S UNDER
FAIRLY STEEP LAPSE RATES. ONE STORM IN SOUTHERN SIOUX COUNTY
PULSED VIGOROUSLY AT TIMES EARLIER THIS AFTERNOON...AND WOULD
EXPECT THIS TO BE THE TREND THROUGH THE REST OF THE AFTERNOON WITH
CONVECTION EAST OF THIS BOUNDARY. DEEP LAYER SHEAR ANALYSIS SHOWS
ROUGHLY 30-40 KTS IN PLACE...SO SOME ORGANIZATION OF CONVECTION IS
POSSIBLE BUT THE MAJORITY OF STORMS WILL REMAIN STRONG IN NATURE
WITH SOME HAIL...GUSTY WINDS AND MODERATE RAINFALL POSSIBLE OUT OF
THE STRONGER ACTIVITY. A WEAK WAVE APPROACHING FROM THE NORTHWEST
COULD KEEP A FEW STORMS GOING THROUGH SUNSET ALONG AND EAST OF THE
LARAMIE RANGE...ESPECIALLY IN AREAS OF OUTFLOW BOUNDARY
INTERACTION SO KEPT ISOLATED POPS FOR THESE AREAS THRU 03Z.
OTHERWISE TONIGHT SHOULD REMAIN DRY AND MILD.

THE SFC BOUNDARY WILL PUSH EAST TONIGHT AS THE WAVE MOVES
OVERHEAD...BUT YET ANOTHER SFC FRONT WILL DROP SOUTH ACROSS THE
PLAINS SUNDAY AFTERNOON. AT THE SAME TIME...A STRONGER SHORTWAVE
APPROACHING FROM THE SOUTHWEST WILL INDUCE STRONGER EAST-
SOUTHEASTERLY WINDS AT THE SFC AND LOW LEVEL MOISTURE ADVECTION
THROUGH THE DAY. THUS...WE ARE ONCE AGAIN EXPECTING ISOLATED
SHOWERS AND THUNDERSTORMS IN THE AFTERNOON FOR THE MOUNTAINS AND
THE WYOMING PLAINS AS THE FRONT PUSHES THROUGH AND WAVE APPROACHES
FROM THE SOUTHWEST. THAT SHORTWAVE WILL MOVE OVERHEAD ON
MONDAY...BRINGING WITH IT A MARKED INCREASE IN MONSOONAL MOISTURE.
PERHAPS WILL SEE SHOWERS/STORMS INITIATE EARLIER IN THE DAY AND
WITH A BROADER COVERAGE OF ACTIVITY ACROSS THE CWA. LOOKING AT
MODERATE TO HEAVY RAINFALL RATES FROM THIS ACTIVITY. WITH THE VERY
DRY ANTECEDENT CONDITIONS WEST OF THE LARAMIE RANGE AND ACROSS
CONVERSE/NIOBRARA COUNTIES...NOT ANTICIPATING ANY SIGNIFICANT
FLOODING ISSUES HERE. AREAS FURTHER SOUTH AND EAST...WILL HAVE TO
WATCH FOR THE POSSIBILITY OF FLASH FLOODING IN AREAS THAT SEE
HEAVIER RAINFALL OVER THE NEXT COUPLE OF DAYS WHICH COULD SATURATE
SOILS.

.LONG TERM...(TUESDAY THROUGH SATURDAY)
ISSUED AT 344 PM MDT SAT AUG 1 2015

MODELS ARE IN A LITTLE BETTER AGREEMENT TODAY IN THE LONG
TERM...BUT STILL STRUGGLING WITH THE TIMING OF SHORT WAVE ENERGY
EMBEDDED IN THE WEST TO NORTHWEST FLOW ALOFT. ALL MODELS NOW
INDICATE A FLATTER RIDGE COMPARED TO THE LAST FEW DAYS...WITH
WEAK SHORTWAVE DISTURBANCES MOVING ACROSS THE AREA. TUESDAY
APPEARS TO BE FAVORABLE FOR SCATTERED COVERAGE OF SHOWERS AND
TSTORMS THROUGH THE AFTERNOON OVER THE HIGH PLAINS...SO KEPT POP
ON THE HIGH SIDE ALONG AND EAST OF I25. THE GFS AND ECMWF SHOW A
PAIR OF STRONGER DISTURBANCES ON WEDNESDAY AND THURSDAY...AS A
COOL FRONT ACCELERATES SOUTHWARD ACROSS THE HIGH PLAINS BRINGING
COOLER TEMPERATURES TO THE REGION. KEPT POP LOW DURING THE
WEDNESDAY- THURSDAY TIME PERIOD BECAUSE OF THE TIMING OF THE FRONT
AND ASSOCIATED DISTURBANCE ALOFT...WHICH ALL MODELS SHOW MOVING
EAST OF THE FORECAST AREA BY THE AFTERNOON. THIS WOULD PUT MOST OF
SOUTHEAST WYOMING UNDER THE MID LEVEL SUBSIDENCE REGION BEHIND
THE TROUGH AXIS...WHICH IS NOT FAVORABLE FOR WIDESPREAD
CONVECTION. HOWEVER...THIS MAY CHANGE IN THE NEAR FUTURE IF MODEL
SOLUTIONS TREND A BIT MORE PROGRESSIVE. THE GFS AND ECMWF
SOLUTIONS ARE SIMILAR DURING THE MIDDLE OF THE WEEK...BUT THE
ECMWF IS FAR MORE WET...SHOWING LARGE AMOUNTS OF QPF EAST OF I25.

FOR LATE IN THE WEEK AND EARLY NEXT WEEKEND...MODELS ARE IN
REASONABLE AGREEMENT SHOWING AN UPPER LEVEL RIDGE AXIS MOVING
ACROSS THE FRONT RANGE...EXTENDING FROM COLORADO NORTHWARD INTO
SOUTHERN CANADA. ONCE THIS RIDGE AXIS PUSHES A BIT FURTHER
EAST...EXPECT A GREATER COVERAGE OF THUNDERSTORMS BY NEXT WEEKEND
AS SOME MONSOON MOISTURE BEGINS TO ADVECT NORTHWARD.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1105 PM MDT SAT AUG 1 2015

BEST CHANCES FOR CONVECTION SHIFTS WEST INTO SOUTHEAST WYOMING
SUNDAY AFTERNOON AS AN UPPER DISTURBANCE APPROACHES FROM THE
WEST. LOOKS LIKE KLAR AND KCYS STAND THE BEST CHANCES FOR TSTMS
DURING THE AFTERNOON HOURS.

&&

.FIRE WEATHER...
ISSUED AT 344 PM MDT SAT AUG 1 2015

HUMIDITIES HAVE DROPPED INTO THE LOW TO MID TEENS THIS AFTERNOON
WEST OF A LINE FROM CHEYENNE- CHADRON. A FEW GUSTS AROUND 20 MPH
ARE OCCURRING ACROSS THIS AREA AS WELL...WITH THE STRONGEST WINDS
IN THE NORTH SNOWY RANGE FOOTHILLS. ISOLATED SHOWERS AND
THUNDERSTORMS DEVELOPED OVER THE HIGH COUNTRY AND ALONG THIS
BOUNDARY...WITH LIGHT RAINFALL LIKELY IN THE MOUNTAINS AND MORE
MODERATE RAINFALL RATES ACROSS THE PLAINS. MONSOONAL MOISTURE WILL
MOVE IN FOR MONDAY AND TUESDAY WITH HIGHER HUMIDITIES AND
INCREASED CHANCES FOR AFTERNOON AND EVENING THUNDERSTORMS. WARMER
AND DRIER WEATHER WILL PREVAIL FOR WEDNESDAY THROUGH FRIDAY.

&&

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

$$

SHORT TERM...RJM
LONG TERM...TJT
AVIATION...GCC
FIRE WEATHER...RJM



000
FXUS65 KCYS 020507
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
1107 PM MDT SAT AUG 1 2015

.SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT)
ISSUED AT 344 PM MDT SAT AUG 1 2015

CONVECTION HAS DEVELOPED THIS AFTERNOON OFF THE HIGHER TERRAIN...IN
ADDITION TO THE SURFACE TROUGH THAT IS SITUATED ROUGHLY NEAR
CHEYENNE TO CHADRON NEBRASKA. MODERATE INSTABILITY IS IN PLACE
EAST OF THIS AREA WITH DEW POINTS IN THE LOW 50S TO LOW 60S UNDER
FAIRLY STEEP LAPSE RATES. ONE STORM IN SOUTHERN SIOUX COUNTY
PULSED VIGOROUSLY AT TIMES EARLIER THIS AFTERNOON...AND WOULD
EXPECT THIS TO BE THE TREND THROUGH THE REST OF THE AFTERNOON WITH
CONVECTION EAST OF THIS BOUNDARY. DEEP LAYER SHEAR ANALYSIS SHOWS
ROUGHLY 30-40 KTS IN PLACE...SO SOME ORGANIZATION OF CONVECTION IS
POSSIBLE BUT THE MAJORITY OF STORMS WILL REMAIN STRONG IN NATURE
WITH SOME HAIL...GUSTY WINDS AND MODERATE RAINFALL POSSIBLE OUT OF
THE STRONGER ACTIVITY. A WEAK WAVE APPROACHING FROM THE NORTHWEST
COULD KEEP A FEW STORMS GOING THROUGH SUNSET ALONG AND EAST OF THE
LARAMIE RANGE...ESPECIALLY IN AREAS OF OUTFLOW BOUNDARY
INTERACTION SO KEPT ISOLATED POPS FOR THESE AREAS THRU 03Z.
OTHERWISE TONIGHT SHOULD REMAIN DRY AND MILD.

THE SFC BOUNDARY WILL PUSH EAST TONIGHT AS THE WAVE MOVES
OVERHEAD...BUT YET ANOTHER SFC FRONT WILL DROP SOUTH ACROSS THE
PLAINS SUNDAY AFTERNOON. AT THE SAME TIME...A STRONGER SHORTWAVE
APPROACHING FROM THE SOUTHWEST WILL INDUCE STRONGER EAST-
SOUTHEASTERLY WINDS AT THE SFC AND LOW LEVEL MOISTURE ADVECTION
THROUGH THE DAY. THUS...WE ARE ONCE AGAIN EXPECTING ISOLATED
SHOWERS AND THUNDERSTORMS IN THE AFTERNOON FOR THE MOUNTAINS AND
THE WYOMING PLAINS AS THE FRONT PUSHES THROUGH AND WAVE APPROACHES
FROM THE SOUTHWEST. THAT SHORTWAVE WILL MOVE OVERHEAD ON
MONDAY...BRINGING WITH IT A MARKED INCREASE IN MONSOONAL MOISTURE.
PERHAPS WILL SEE SHOWERS/STORMS INITIATE EARLIER IN THE DAY AND
WITH A BROADER COVERAGE OF ACTIVITY ACROSS THE CWA. LOOKING AT
MODERATE TO HEAVY RAINFALL RATES FROM THIS ACTIVITY. WITH THE VERY
DRY ANTECEDENT CONDITIONS WEST OF THE LARAMIE RANGE AND ACROSS
CONVERSE/NIOBRARA COUNTIES...NOT ANTICIPATING ANY SIGNIFICANT
FLOODING ISSUES HERE. AREAS FURTHER SOUTH AND EAST...WILL HAVE TO
WATCH FOR THE POSSIBILITY OF FLASH FLOODING IN AREAS THAT SEE
HEAVIER RAINFALL OVER THE NEXT COUPLE OF DAYS WHICH COULD SATURATE
SOILS.

.LONG TERM...(TUESDAY THROUGH SATURDAY)
ISSUED AT 344 PM MDT SAT AUG 1 2015

MODELS ARE IN A LITTLE BETTER AGREEMENT TODAY IN THE LONG
TERM...BUT STILL STRUGGLING WITH THE TIMING OF SHORT WAVE ENERGY
EMBEDDED IN THE WEST TO NORTHWEST FLOW ALOFT. ALL MODELS NOW
INDICATE A FLATTER RIDGE COMPARED TO THE LAST FEW DAYS...WITH
WEAK SHORTWAVE DISTURBANCES MOVING ACROSS THE AREA. TUESDAY
APPEARS TO BE FAVORABLE FOR SCATTERED COVERAGE OF SHOWERS AND
TSTORMS THROUGH THE AFTERNOON OVER THE HIGH PLAINS...SO KEPT POP
ON THE HIGH SIDE ALONG AND EAST OF I25. THE GFS AND ECMWF SHOW A
PAIR OF STRONGER DISTURBANCES ON WEDNESDAY AND THURSDAY...AS A
COOL FRONT ACCELERATES SOUTHWARD ACROSS THE HIGH PLAINS BRINGING
COOLER TEMPERATURES TO THE REGION. KEPT POP LOW DURING THE
WEDNESDAY- THURSDAY TIME PERIOD BECAUSE OF THE TIMING OF THE FRONT
AND ASSOCIATED DISTURBANCE ALOFT...WHICH ALL MODELS SHOW MOVING
EAST OF THE FORECAST AREA BY THE AFTERNOON. THIS WOULD PUT MOST OF
SOUTHEAST WYOMING UNDER THE MID LEVEL SUBSIDENCE REGION BEHIND
THE TROUGH AXIS...WHICH IS NOT FAVORABLE FOR WIDESPREAD
CONVECTION. HOWEVER...THIS MAY CHANGE IN THE NEAR FUTURE IF MODEL
SOLUTIONS TREND A BIT MORE PROGRESSIVE. THE GFS AND ECMWF
SOLUTIONS ARE SIMILAR DURING THE MIDDLE OF THE WEEK...BUT THE
ECMWF IS FAR MORE WET...SHOWING LARGE AMOUNTS OF QPF EAST OF I25.

FOR LATE IN THE WEEK AND EARLY NEXT WEEKEND...MODELS ARE IN
REASONABLE AGREEMENT SHOWING AN UPPER LEVEL RIDGE AXIS MOVING
ACROSS THE FRONT RANGE...EXTENDING FROM COLORADO NORTHWARD INTO
SOUTHERN CANADA. ONCE THIS RIDGE AXIS PUSHES A BIT FURTHER
EAST...EXPECT A GREATER COVERAGE OF THUNDERSTORMS BY NEXT WEEKEND
AS SOME MONSOON MOISTURE BEGINS TO ADVECT NORTHWARD.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1105 PM MDT SAT AUG 1 2015

BEST CHANCES FOR CONVECTION SHIFTS WEST INTO SOUTHEAST WYOMING
SUNDAY AFTERNOON AS AN UPPER DISTURBANCE APPROACHES FROM THE
WEST. LOOKS LIKE KLAR AND KCYS STAND THE BEST CHANCES FOR TSTMS
DURING THE AFTERNOON HOURS.

&&

.FIRE WEATHER...
ISSUED AT 344 PM MDT SAT AUG 1 2015

HUMIDITIES HAVE DROPPED INTO THE LOW TO MID TEENS THIS AFTERNOON
WEST OF A LINE FROM CHEYENNE- CHADRON. A FEW GUSTS AROUND 20 MPH
ARE OCCURRING ACROSS THIS AREA AS WELL...WITH THE STRONGEST WINDS
IN THE NORTH SNOWY RANGE FOOTHILLS. ISOLATED SHOWERS AND
THUNDERSTORMS DEVELOPED OVER THE HIGH COUNTRY AND ALONG THIS
BOUNDARY...WITH LIGHT RAINFALL LIKELY IN THE MOUNTAINS AND MORE
MODERATE RAINFALL RATES ACROSS THE PLAINS. MONSOONAL MOISTURE WILL
MOVE IN FOR MONDAY AND TUESDAY WITH HIGHER HUMIDITIES AND
INCREASED CHANCES FOR AFTERNOON AND EVENING THUNDERSTORMS. WARMER
AND DRIER WEATHER WILL PREVAIL FOR WEDNESDAY THROUGH FRIDAY.

&&

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

$$

SHORT TERM...RJM
LONG TERM...TJT
AVIATION...GCC
FIRE WEATHER...RJM



000
FXUS65 KCYS 020507
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
1107 PM MDT SAT AUG 1 2015

.SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT)
ISSUED AT 344 PM MDT SAT AUG 1 2015

CONVECTION HAS DEVELOPED THIS AFTERNOON OFF THE HIGHER TERRAIN...IN
ADDITION TO THE SURFACE TROUGH THAT IS SITUATED ROUGHLY NEAR
CHEYENNE TO CHADRON NEBRASKA. MODERATE INSTABILITY IS IN PLACE
EAST OF THIS AREA WITH DEW POINTS IN THE LOW 50S TO LOW 60S UNDER
FAIRLY STEEP LAPSE RATES. ONE STORM IN SOUTHERN SIOUX COUNTY
PULSED VIGOROUSLY AT TIMES EARLIER THIS AFTERNOON...AND WOULD
EXPECT THIS TO BE THE TREND THROUGH THE REST OF THE AFTERNOON WITH
CONVECTION EAST OF THIS BOUNDARY. DEEP LAYER SHEAR ANALYSIS SHOWS
ROUGHLY 30-40 KTS IN PLACE...SO SOME ORGANIZATION OF CONVECTION IS
POSSIBLE BUT THE MAJORITY OF STORMS WILL REMAIN STRONG IN NATURE
WITH SOME HAIL...GUSTY WINDS AND MODERATE RAINFALL POSSIBLE OUT OF
THE STRONGER ACTIVITY. A WEAK WAVE APPROACHING FROM THE NORTHWEST
COULD KEEP A FEW STORMS GOING THROUGH SUNSET ALONG AND EAST OF THE
LARAMIE RANGE...ESPECIALLY IN AREAS OF OUTFLOW BOUNDARY
INTERACTION SO KEPT ISOLATED POPS FOR THESE AREAS THRU 03Z.
OTHERWISE TONIGHT SHOULD REMAIN DRY AND MILD.

THE SFC BOUNDARY WILL PUSH EAST TONIGHT AS THE WAVE MOVES
OVERHEAD...BUT YET ANOTHER SFC FRONT WILL DROP SOUTH ACROSS THE
PLAINS SUNDAY AFTERNOON. AT THE SAME TIME...A STRONGER SHORTWAVE
APPROACHING FROM THE SOUTHWEST WILL INDUCE STRONGER EAST-
SOUTHEASTERLY WINDS AT THE SFC AND LOW LEVEL MOISTURE ADVECTION
THROUGH THE DAY. THUS...WE ARE ONCE AGAIN EXPECTING ISOLATED
SHOWERS AND THUNDERSTORMS IN THE AFTERNOON FOR THE MOUNTAINS AND
THE WYOMING PLAINS AS THE FRONT PUSHES THROUGH AND WAVE APPROACHES
FROM THE SOUTHWEST. THAT SHORTWAVE WILL MOVE OVERHEAD ON
MONDAY...BRINGING WITH IT A MARKED INCREASE IN MONSOONAL MOISTURE.
PERHAPS WILL SEE SHOWERS/STORMS INITIATE EARLIER IN THE DAY AND
WITH A BROADER COVERAGE OF ACTIVITY ACROSS THE CWA. LOOKING AT
MODERATE TO HEAVY RAINFALL RATES FROM THIS ACTIVITY. WITH THE VERY
DRY ANTECEDENT CONDITIONS WEST OF THE LARAMIE RANGE AND ACROSS
CONVERSE/NIOBRARA COUNTIES...NOT ANTICIPATING ANY SIGNIFICANT
FLOODING ISSUES HERE. AREAS FURTHER SOUTH AND EAST...WILL HAVE TO
WATCH FOR THE POSSIBILITY OF FLASH FLOODING IN AREAS THAT SEE
HEAVIER RAINFALL OVER THE NEXT COUPLE OF DAYS WHICH COULD SATURATE
SOILS.

.LONG TERM...(TUESDAY THROUGH SATURDAY)
ISSUED AT 344 PM MDT SAT AUG 1 2015

MODELS ARE IN A LITTLE BETTER AGREEMENT TODAY IN THE LONG
TERM...BUT STILL STRUGGLING WITH THE TIMING OF SHORT WAVE ENERGY
EMBEDDED IN THE WEST TO NORTHWEST FLOW ALOFT. ALL MODELS NOW
INDICATE A FLATTER RIDGE COMPARED TO THE LAST FEW DAYS...WITH
WEAK SHORTWAVE DISTURBANCES MOVING ACROSS THE AREA. TUESDAY
APPEARS TO BE FAVORABLE FOR SCATTERED COVERAGE OF SHOWERS AND
TSTORMS THROUGH THE AFTERNOON OVER THE HIGH PLAINS...SO KEPT POP
ON THE HIGH SIDE ALONG AND EAST OF I25. THE GFS AND ECMWF SHOW A
PAIR OF STRONGER DISTURBANCES ON WEDNESDAY AND THURSDAY...AS A
COOL FRONT ACCELERATES SOUTHWARD ACROSS THE HIGH PLAINS BRINGING
COOLER TEMPERATURES TO THE REGION. KEPT POP LOW DURING THE
WEDNESDAY- THURSDAY TIME PERIOD BECAUSE OF THE TIMING OF THE FRONT
AND ASSOCIATED DISTURBANCE ALOFT...WHICH ALL MODELS SHOW MOVING
EAST OF THE FORECAST AREA BY THE AFTERNOON. THIS WOULD PUT MOST OF
SOUTHEAST WYOMING UNDER THE MID LEVEL SUBSIDENCE REGION BEHIND
THE TROUGH AXIS...WHICH IS NOT FAVORABLE FOR WIDESPREAD
CONVECTION. HOWEVER...THIS MAY CHANGE IN THE NEAR FUTURE IF MODEL
SOLUTIONS TREND A BIT MORE PROGRESSIVE. THE GFS AND ECMWF
SOLUTIONS ARE SIMILAR DURING THE MIDDLE OF THE WEEK...BUT THE
ECMWF IS FAR MORE WET...SHOWING LARGE AMOUNTS OF QPF EAST OF I25.

FOR LATE IN THE WEEK AND EARLY NEXT WEEKEND...MODELS ARE IN
REASONABLE AGREEMENT SHOWING AN UPPER LEVEL RIDGE AXIS MOVING
ACROSS THE FRONT RANGE...EXTENDING FROM COLORADO NORTHWARD INTO
SOUTHERN CANADA. ONCE THIS RIDGE AXIS PUSHES A BIT FURTHER
EAST...EXPECT A GREATER COVERAGE OF THUNDERSTORMS BY NEXT WEEKEND
AS SOME MONSOON MOISTURE BEGINS TO ADVECT NORTHWARD.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1105 PM MDT SAT AUG 1 2015

BEST CHANCES FOR CONVECTION SHIFTS WEST INTO SOUTHEAST WYOMING
SUNDAY AFTERNOON AS AN UPPER DISTURBANCE APPROACHES FROM THE
WEST. LOOKS LIKE KLAR AND KCYS STAND THE BEST CHANCES FOR TSTMS
DURING THE AFTERNOON HOURS.

&&

.FIRE WEATHER...
ISSUED AT 344 PM MDT SAT AUG 1 2015

HUMIDITIES HAVE DROPPED INTO THE LOW TO MID TEENS THIS AFTERNOON
WEST OF A LINE FROM CHEYENNE- CHADRON. A FEW GUSTS AROUND 20 MPH
ARE OCCURRING ACROSS THIS AREA AS WELL...WITH THE STRONGEST WINDS
IN THE NORTH SNOWY RANGE FOOTHILLS. ISOLATED SHOWERS AND
THUNDERSTORMS DEVELOPED OVER THE HIGH COUNTRY AND ALONG THIS
BOUNDARY...WITH LIGHT RAINFALL LIKELY IN THE MOUNTAINS AND MORE
MODERATE RAINFALL RATES ACROSS THE PLAINS. MONSOONAL MOISTURE WILL
MOVE IN FOR MONDAY AND TUESDAY WITH HIGHER HUMIDITIES AND
INCREASED CHANCES FOR AFTERNOON AND EVENING THUNDERSTORMS. WARMER
AND DRIER WEATHER WILL PREVAIL FOR WEDNESDAY THROUGH FRIDAY.

&&

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

$$

SHORT TERM...RJM
LONG TERM...TJT
AVIATION...GCC
FIRE WEATHER...RJM



000
FXUS65 KCYS 020507
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
1107 PM MDT SAT AUG 1 2015

.SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT)
ISSUED AT 344 PM MDT SAT AUG 1 2015

CONVECTION HAS DEVELOPED THIS AFTERNOON OFF THE HIGHER TERRAIN...IN
ADDITION TO THE SURFACE TROUGH THAT IS SITUATED ROUGHLY NEAR
CHEYENNE TO CHADRON NEBRASKA. MODERATE INSTABILITY IS IN PLACE
EAST OF THIS AREA WITH DEW POINTS IN THE LOW 50S TO LOW 60S UNDER
FAIRLY STEEP LAPSE RATES. ONE STORM IN SOUTHERN SIOUX COUNTY
PULSED VIGOROUSLY AT TIMES EARLIER THIS AFTERNOON...AND WOULD
EXPECT THIS TO BE THE TREND THROUGH THE REST OF THE AFTERNOON WITH
CONVECTION EAST OF THIS BOUNDARY. DEEP LAYER SHEAR ANALYSIS SHOWS
ROUGHLY 30-40 KTS IN PLACE...SO SOME ORGANIZATION OF CONVECTION IS
POSSIBLE BUT THE MAJORITY OF STORMS WILL REMAIN STRONG IN NATURE
WITH SOME HAIL...GUSTY WINDS AND MODERATE RAINFALL POSSIBLE OUT OF
THE STRONGER ACTIVITY. A WEAK WAVE APPROACHING FROM THE NORTHWEST
COULD KEEP A FEW STORMS GOING THROUGH SUNSET ALONG AND EAST OF THE
LARAMIE RANGE...ESPECIALLY IN AREAS OF OUTFLOW BOUNDARY
INTERACTION SO KEPT ISOLATED POPS FOR THESE AREAS THRU 03Z.
OTHERWISE TONIGHT SHOULD REMAIN DRY AND MILD.

THE SFC BOUNDARY WILL PUSH EAST TONIGHT AS THE WAVE MOVES
OVERHEAD...BUT YET ANOTHER SFC FRONT WILL DROP SOUTH ACROSS THE
PLAINS SUNDAY AFTERNOON. AT THE SAME TIME...A STRONGER SHORTWAVE
APPROACHING FROM THE SOUTHWEST WILL INDUCE STRONGER EAST-
SOUTHEASTERLY WINDS AT THE SFC AND LOW LEVEL MOISTURE ADVECTION
THROUGH THE DAY. THUS...WE ARE ONCE AGAIN EXPECTING ISOLATED
SHOWERS AND THUNDERSTORMS IN THE AFTERNOON FOR THE MOUNTAINS AND
THE WYOMING PLAINS AS THE FRONT PUSHES THROUGH AND WAVE APPROACHES
FROM THE SOUTHWEST. THAT SHORTWAVE WILL MOVE OVERHEAD ON
MONDAY...BRINGING WITH IT A MARKED INCREASE IN MONSOONAL MOISTURE.
PERHAPS WILL SEE SHOWERS/STORMS INITIATE EARLIER IN THE DAY AND
WITH A BROADER COVERAGE OF ACTIVITY ACROSS THE CWA. LOOKING AT
MODERATE TO HEAVY RAINFALL RATES FROM THIS ACTIVITY. WITH THE VERY
DRY ANTECEDENT CONDITIONS WEST OF THE LARAMIE RANGE AND ACROSS
CONVERSE/NIOBRARA COUNTIES...NOT ANTICIPATING ANY SIGNIFICANT
FLOODING ISSUES HERE. AREAS FURTHER SOUTH AND EAST...WILL HAVE TO
WATCH FOR THE POSSIBILITY OF FLASH FLOODING IN AREAS THAT SEE
HEAVIER RAINFALL OVER THE NEXT COUPLE OF DAYS WHICH COULD SATURATE
SOILS.

.LONG TERM...(TUESDAY THROUGH SATURDAY)
ISSUED AT 344 PM MDT SAT AUG 1 2015

MODELS ARE IN A LITTLE BETTER AGREEMENT TODAY IN THE LONG
TERM...BUT STILL STRUGGLING WITH THE TIMING OF SHORT WAVE ENERGY
EMBEDDED IN THE WEST TO NORTHWEST FLOW ALOFT. ALL MODELS NOW
INDICATE A FLATTER RIDGE COMPARED TO THE LAST FEW DAYS...WITH
WEAK SHORTWAVE DISTURBANCES MOVING ACROSS THE AREA. TUESDAY
APPEARS TO BE FAVORABLE FOR SCATTERED COVERAGE OF SHOWERS AND
TSTORMS THROUGH THE AFTERNOON OVER THE HIGH PLAINS...SO KEPT POP
ON THE HIGH SIDE ALONG AND EAST OF I25. THE GFS AND ECMWF SHOW A
PAIR OF STRONGER DISTURBANCES ON WEDNESDAY AND THURSDAY...AS A
COOL FRONT ACCELERATES SOUTHWARD ACROSS THE HIGH PLAINS BRINGING
COOLER TEMPERATURES TO THE REGION. KEPT POP LOW DURING THE
WEDNESDAY- THURSDAY TIME PERIOD BECAUSE OF THE TIMING OF THE FRONT
AND ASSOCIATED DISTURBANCE ALOFT...WHICH ALL MODELS SHOW MOVING
EAST OF THE FORECAST AREA BY THE AFTERNOON. THIS WOULD PUT MOST OF
SOUTHEAST WYOMING UNDER THE MID LEVEL SUBSIDENCE REGION BEHIND
THE TROUGH AXIS...WHICH IS NOT FAVORABLE FOR WIDESPREAD
CONVECTION. HOWEVER...THIS MAY CHANGE IN THE NEAR FUTURE IF MODEL
SOLUTIONS TREND A BIT MORE PROGRESSIVE. THE GFS AND ECMWF
SOLUTIONS ARE SIMILAR DURING THE MIDDLE OF THE WEEK...BUT THE
ECMWF IS FAR MORE WET...SHOWING LARGE AMOUNTS OF QPF EAST OF I25.

FOR LATE IN THE WEEK AND EARLY NEXT WEEKEND...MODELS ARE IN
REASONABLE AGREEMENT SHOWING AN UPPER LEVEL RIDGE AXIS MOVING
ACROSS THE FRONT RANGE...EXTENDING FROM COLORADO NORTHWARD INTO
SOUTHERN CANADA. ONCE THIS RIDGE AXIS PUSHES A BIT FURTHER
EAST...EXPECT A GREATER COVERAGE OF THUNDERSTORMS BY NEXT WEEKEND
AS SOME MONSOON MOISTURE BEGINS TO ADVECT NORTHWARD.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1105 PM MDT SAT AUG 1 2015

BEST CHANCES FOR CONVECTION SHIFTS WEST INTO SOUTHEAST WYOMING
SUNDAY AFTERNOON AS AN UPPER DISTURBANCE APPROACHES FROM THE
WEST. LOOKS LIKE KLAR AND KCYS STAND THE BEST CHANCES FOR TSTMS
DURING THE AFTERNOON HOURS.

&&

.FIRE WEATHER...
ISSUED AT 344 PM MDT SAT AUG 1 2015

HUMIDITIES HAVE DROPPED INTO THE LOW TO MID TEENS THIS AFTERNOON
WEST OF A LINE FROM CHEYENNE- CHADRON. A FEW GUSTS AROUND 20 MPH
ARE OCCURRING ACROSS THIS AREA AS WELL...WITH THE STRONGEST WINDS
IN THE NORTH SNOWY RANGE FOOTHILLS. ISOLATED SHOWERS AND
THUNDERSTORMS DEVELOPED OVER THE HIGH COUNTRY AND ALONG THIS
BOUNDARY...WITH LIGHT RAINFALL LIKELY IN THE MOUNTAINS AND MORE
MODERATE RAINFALL RATES ACROSS THE PLAINS. MONSOONAL MOISTURE WILL
MOVE IN FOR MONDAY AND TUESDAY WITH HIGHER HUMIDITIES AND
INCREASED CHANCES FOR AFTERNOON AND EVENING THUNDERSTORMS. WARMER
AND DRIER WEATHER WILL PREVAIL FOR WEDNESDAY THROUGH FRIDAY.

&&

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

$$

SHORT TERM...RJM
LONG TERM...TJT
AVIATION...GCC
FIRE WEATHER...RJM




000
FXUS65 KCYS 020441
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
1041 PM MDT SAT AUG 1 2015

.SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT)
ISSUED AT 344 PM MDT SAT AUG 1 2015

CONVECTION HAS DEVELOPED THIS AFTERNOON OFF THE HIGHER TERRAIN...IN
ADDITION TO THE SURFACE TROUGH THAT IS SITUATED ROUGHLY NEAR
CHEYENNE TO CHADRON NEBRASKA. MODERATE INSTABILITY IS IN PLACE
EAST OF THIS AREA WITH DEW POINTS IN THE LOW 50S TO LOW 60S UNDER
FAIRLY STEEP LAPSE RATES. ONE STORM IN SOUTHERN SIOUX COUNTY
PULSED VIGOROUSLY AT TIMES EARLIER THIS AFTERNOON...AND WOULD
EXPECT THIS TO BE THE TREND THROUGH THE REST OF THE AFTERNOON WITH
CONVECTION EAST OF THIS BOUNDARY. DEEP LAYER SHEAR ANALYSIS SHOWS
ROUGHLY 30-40 KTS IN PLACE...SO SOME ORGANIZATION OF CONVECTION IS
POSSIBLE BUT THE MAJORITY OF STORMS WILL REMAIN STRONG IN NATURE
WITH SOME HAIL...GUSTY WINDS AND MODERATE RAINFALL POSSIBLE OUT OF
THE STRONGER ACTIVITY. A WEAK WAVE APPROACHING FROM THE NORTHWEST
COULD KEEP A FEW STORMS GOING THROUGH SUNSET ALONG AND EAST OF THE
LARAMIE RANGE...ESPECIALLY IN AREAS OF OUTFLOW BOUNDARY
INTERACTION SO KEPT ISOLATED POPS FOR THESE AREAS THRU 03Z.
OTHERWISE TONIGHT SHOULD REMAIN DRY AND MILD.

THE SFC BOUNDARY WILL PUSH EAST TONIGHT AS THE WAVE MOVES
OVERHEAD...BUT YET ANOTHER SFC FRONT WILL DROP SOUTH ACROSS THE
PLAINS SUNDAY AFTERNOON. AT THE SAME TIME...A STRONGER SHORTWAVE
APPROACHING FROM THE SOUTHWEST WILL INDUCE STRONGER EAST-
SOUTHEASTERLY WINDS AT THE SFC AND LOW LEVEL MOISTURE ADVECTION
THROUGH THE DAY. THUS...WE ARE ONCE AGAIN EXPECTING ISOLATED
SHOWERS AND THUNDERSTORMS IN THE AFTERNOON FOR THE MOUNTAINS AND
THE WYOMING PLAINS AS THE FRONT PUSHES THROUGH AND WAVE APPROACHES
FROM THE SOUTHWEST. THAT SHORTWAVE WILL MOVE OVERHEAD ON
MONDAY...BRINGING WITH IT A MARKED INCREASE IN MONSOONAL MOISTURE.
PERHAPS WILL SEE SHOWERS/STORMS INITIATE EARLIER IN THE DAY AND
WITH A BROADER COVERAGE OF ACTIVITY ACROSS THE CWA. LOOKING AT
MODERATE TO HEAVY RAINFALL RATES FROM THIS ACTIVITY. WITH THE VERY
DRY ANTECEDENT CONDITIONS WEST OF THE LARAMIE RANGE AND ACROSS
CONVERSE/NIOBRARA COUNTIES...NOT ANTICIPATING ANY SIGNIFICANT
FLOODING ISSUES HERE. AREAS FURTHER SOUTH AND EAST...WILL HAVE TO
WATCH FOR THE POSSIBILITY OF FLASH FLOODING IN AREAS THAT SEE
HEAVIER RAINFALL OVER THE NEXT COUPLE OF DAYS WHICH COULD SATURATE
SOILS.

.LONG TERM...(TUESDAY THROUGH SATURDAY)
ISSUED AT 344 PM MDT SAT AUG 1 2015

MODELS ARE IN A LITTLE BETTER AGREEMENT TODAY IN THE LONG
TERM...BUT STILL STRUGGLING WITH THE TIMING OF SHORT WAVE ENERGY
EMBEDDED IN THE WEST TO NORTHWEST FLOW ALOFT. ALL MODELS NOW
INDICATE A FLATTER RIDGE COMPARED TO THE LAST FEW DAYS...WITH
WEAK SHORTWAVE DISTURBANCES MOVING ACROSS THE AREA. TUESDAY
APPEARS TO BE FAVORABLE FOR SCATTERED COVERAGE OF SHOWERS AND
TSTORMS THROUGH THE AFTERNOON OVER THE HIGH PLAINS...SO KEPT POP
ON THE HIGH SIDE ALONG AND EAST OF I25. THE GFS AND ECMWF SHOW A
PAIR OF STRONGER DISTURBANCES ON WEDNESDAY AND THURSDAY...AS A
COOL FRONT ACCELERATES SOUTHWARD ACROSS THE HIGH PLAINS BRINGING
COOLER TEMPERATURES TO THE REGION. KEPT POP LOW DURING THE
WEDNESDAY- THURSDAY TIME PERIOD BECAUSE OF THE TIMING OF THE FRONT
AND ASSOCIATED DISTURBANCE ALOFT...WHICH ALL MODELS SHOW MOVING
EAST OF THE FORECAST AREA BY THE AFTERNOON. THIS WOULD PUT MOST OF
SOUTHEAST WYOMING UNDER THE MID LEVEL SUBSIDENCE REGION BEHIND
THE TROUGH AXIS...WHICH IS NOT FAVORABLE FOR WIDESPREAD
CONVECTION. HOWEVER...THIS MAY CHANGE IN THE NEAR FUTURE IF MODEL
SOLUTIONS TREND A BIT MORE PROGRESSIVE. THE GFS AND ECMWF
SOLUTIONS ARE SIMILAR DURING THE MIDDLE OF THE WEEK...BUT THE
ECMWF IS FAR MORE WET...SHOWING LARGE AMOUNTS OF QPF EAST OF I25.

FOR LATE IN THE WEEK AND EARLY NEXT WEEKEND...MODELS ARE IN
REASONABLE AGREEMENT SHOWING AN UPPER LEVEL RIDGE AXIS MOVING
ACROSS THE FRONT RANGE...EXTENDING FROM COLORADO NORTHWARD INTO
SOUTHERN CANADA. ONCE THIS RIDGE AXIS PUSHES A BIT FURTHER
EAST...EXPECT A GREATER COVERAGE OF THUNDERSTORMS BY NEXT WEEKEND
AS SOME MONSOON MOISTURE BEGINS TO ADVECT NORTHWARD.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1032 PM MDT SAT AUG 1 2015

VFR CONDITIONS ARE FORECAST FOR SOUTHEAST WY AND WESTERN NE
PANHANDLE AERODROMES THROUGH SUNDAY. WINDS WILL BE LIGHT AND
VARIABLE THROUGH SUNDAY MORNING...THEN BECOMING EASTERLY. IT
WILL BE BREEZY AT TIMES WITH GUSTS TO 20 KT. ISOLATED AFTERNOON
TSTORMS WILL DEVELOP OVER THE MOUNTAINS AND ADJACENT SOUTHEAST WY
PLAINS SUNDAY...WITH THE CYS AND LAR AERODROMES POSSIBLY IMPACTED
AFTER 20Z.

&&

.FIRE WEATHER...
ISSUED AT 344 PM MDT SAT AUG 1 2015

HUMIDITIES HAVE DROPPED INTO THE LOW TO MID TEENS THIS AFTERNOON
WEST OF A LINE FROM CHEYENNE- CHADRON. A FEW GUSTS AROUND 20 MPH
ARE OCCURRING ACROSS THIS AREA AS WELL...WITH THE STRONGEST WINDS
IN THE NORTH SNOWY RANGE FOOTHILLS. ISOLATED SHOWERS AND
THUNDERSTORMS DEVELOPED OVER THE HIGH COUNTRY AND ALONG THIS
BOUNDARY...WITH LIGHT RAINFALL LIKELY IN THE MOUNTAINS AND MORE
MODERATE RAINFALL RATES ACROSS THE PLAINS. MONSOONAL MOISTURE WILL
MOVE IN FOR MONDAY AND TUESDAY WITH HIGHER HUMIDITIES AND
INCREASED CHANCES FOR AFTERNOON AND EVENING THUNDERSTORMS. WARMER
AND DRIER WEATHER WILL PREVAIL FOR WEDNESDAY THROUGH FRIDAY.

&&

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

$$

SHORT TERM...RJM
LONG TERM...TJT
AVIATION...MAJ
FIRE WEATHER...RJM




000
FXUS65 KCYS 020441
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
1041 PM MDT SAT AUG 1 2015

.SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT)
ISSUED AT 344 PM MDT SAT AUG 1 2015

CONVECTION HAS DEVELOPED THIS AFTERNOON OFF THE HIGHER TERRAIN...IN
ADDITION TO THE SURFACE TROUGH THAT IS SITUATED ROUGHLY NEAR
CHEYENNE TO CHADRON NEBRASKA. MODERATE INSTABILITY IS IN PLACE
EAST OF THIS AREA WITH DEW POINTS IN THE LOW 50S TO LOW 60S UNDER
FAIRLY STEEP LAPSE RATES. ONE STORM IN SOUTHERN SIOUX COUNTY
PULSED VIGOROUSLY AT TIMES EARLIER THIS AFTERNOON...AND WOULD
EXPECT THIS TO BE THE TREND THROUGH THE REST OF THE AFTERNOON WITH
CONVECTION EAST OF THIS BOUNDARY. DEEP LAYER SHEAR ANALYSIS SHOWS
ROUGHLY 30-40 KTS IN PLACE...SO SOME ORGANIZATION OF CONVECTION IS
POSSIBLE BUT THE MAJORITY OF STORMS WILL REMAIN STRONG IN NATURE
WITH SOME HAIL...GUSTY WINDS AND MODERATE RAINFALL POSSIBLE OUT OF
THE STRONGER ACTIVITY. A WEAK WAVE APPROACHING FROM THE NORTHWEST
COULD KEEP A FEW STORMS GOING THROUGH SUNSET ALONG AND EAST OF THE
LARAMIE RANGE...ESPECIALLY IN AREAS OF OUTFLOW BOUNDARY
INTERACTION SO KEPT ISOLATED POPS FOR THESE AREAS THRU 03Z.
OTHERWISE TONIGHT SHOULD REMAIN DRY AND MILD.

THE SFC BOUNDARY WILL PUSH EAST TONIGHT AS THE WAVE MOVES
OVERHEAD...BUT YET ANOTHER SFC FRONT WILL DROP SOUTH ACROSS THE
PLAINS SUNDAY AFTERNOON. AT THE SAME TIME...A STRONGER SHORTWAVE
APPROACHING FROM THE SOUTHWEST WILL INDUCE STRONGER EAST-
SOUTHEASTERLY WINDS AT THE SFC AND LOW LEVEL MOISTURE ADVECTION
THROUGH THE DAY. THUS...WE ARE ONCE AGAIN EXPECTING ISOLATED
SHOWERS AND THUNDERSTORMS IN THE AFTERNOON FOR THE MOUNTAINS AND
THE WYOMING PLAINS AS THE FRONT PUSHES THROUGH AND WAVE APPROACHES
FROM THE SOUTHWEST. THAT SHORTWAVE WILL MOVE OVERHEAD ON
MONDAY...BRINGING WITH IT A MARKED INCREASE IN MONSOONAL MOISTURE.
PERHAPS WILL SEE SHOWERS/STORMS INITIATE EARLIER IN THE DAY AND
WITH A BROADER COVERAGE OF ACTIVITY ACROSS THE CWA. LOOKING AT
MODERATE TO HEAVY RAINFALL RATES FROM THIS ACTIVITY. WITH THE VERY
DRY ANTECEDENT CONDITIONS WEST OF THE LARAMIE RANGE AND ACROSS
CONVERSE/NIOBRARA COUNTIES...NOT ANTICIPATING ANY SIGNIFICANT
FLOODING ISSUES HERE. AREAS FURTHER SOUTH AND EAST...WILL HAVE TO
WATCH FOR THE POSSIBILITY OF FLASH FLOODING IN AREAS THAT SEE
HEAVIER RAINFALL OVER THE NEXT COUPLE OF DAYS WHICH COULD SATURATE
SOILS.

.LONG TERM...(TUESDAY THROUGH SATURDAY)
ISSUED AT 344 PM MDT SAT AUG 1 2015

MODELS ARE IN A LITTLE BETTER AGREEMENT TODAY IN THE LONG
TERM...BUT STILL STRUGGLING WITH THE TIMING OF SHORT WAVE ENERGY
EMBEDDED IN THE WEST TO NORTHWEST FLOW ALOFT. ALL MODELS NOW
INDICATE A FLATTER RIDGE COMPARED TO THE LAST FEW DAYS...WITH
WEAK SHORTWAVE DISTURBANCES MOVING ACROSS THE AREA. TUESDAY
APPEARS TO BE FAVORABLE FOR SCATTERED COVERAGE OF SHOWERS AND
TSTORMS THROUGH THE AFTERNOON OVER THE HIGH PLAINS...SO KEPT POP
ON THE HIGH SIDE ALONG AND EAST OF I25. THE GFS AND ECMWF SHOW A
PAIR OF STRONGER DISTURBANCES ON WEDNESDAY AND THURSDAY...AS A
COOL FRONT ACCELERATES SOUTHWARD ACROSS THE HIGH PLAINS BRINGING
COOLER TEMPERATURES TO THE REGION. KEPT POP LOW DURING THE
WEDNESDAY- THURSDAY TIME PERIOD BECAUSE OF THE TIMING OF THE FRONT
AND ASSOCIATED DISTURBANCE ALOFT...WHICH ALL MODELS SHOW MOVING
EAST OF THE FORECAST AREA BY THE AFTERNOON. THIS WOULD PUT MOST OF
SOUTHEAST WYOMING UNDER THE MID LEVEL SUBSIDENCE REGION BEHIND
THE TROUGH AXIS...WHICH IS NOT FAVORABLE FOR WIDESPREAD
CONVECTION. HOWEVER...THIS MAY CHANGE IN THE NEAR FUTURE IF MODEL
SOLUTIONS TREND A BIT MORE PROGRESSIVE. THE GFS AND ECMWF
SOLUTIONS ARE SIMILAR DURING THE MIDDLE OF THE WEEK...BUT THE
ECMWF IS FAR MORE WET...SHOWING LARGE AMOUNTS OF QPF EAST OF I25.

FOR LATE IN THE WEEK AND EARLY NEXT WEEKEND...MODELS ARE IN
REASONABLE AGREEMENT SHOWING AN UPPER LEVEL RIDGE AXIS MOVING
ACROSS THE FRONT RANGE...EXTENDING FROM COLORADO NORTHWARD INTO
SOUTHERN CANADA. ONCE THIS RIDGE AXIS PUSHES A BIT FURTHER
EAST...EXPECT A GREATER COVERAGE OF THUNDERSTORMS BY NEXT WEEKEND
AS SOME MONSOON MOISTURE BEGINS TO ADVECT NORTHWARD.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1032 PM MDT SAT AUG 1 2015

VFR CONDITIONS ARE FORECAST FOR SOUTHEAST WY AND WESTERN NE
PANHANDLE AERODROMES THROUGH SUNDAY. WINDS WILL BE LIGHT AND
VARIABLE THROUGH SUNDAY MORNING...THEN BECOMING EASTERLY. IT
WILL BE BREEZY AT TIMES WITH GUSTS TO 20 KT. ISOLATED AFTERNOON
TSTORMS WILL DEVELOP OVER THE MOUNTAINS AND ADJACENT SOUTHEAST WY
PLAINS SUNDAY...WITH THE CYS AND LAR AERODROMES POSSIBLY IMPACTED
AFTER 20Z.

&&

.FIRE WEATHER...
ISSUED AT 344 PM MDT SAT AUG 1 2015

HUMIDITIES HAVE DROPPED INTO THE LOW TO MID TEENS THIS AFTERNOON
WEST OF A LINE FROM CHEYENNE- CHADRON. A FEW GUSTS AROUND 20 MPH
ARE OCCURRING ACROSS THIS AREA AS WELL...WITH THE STRONGEST WINDS
IN THE NORTH SNOWY RANGE FOOTHILLS. ISOLATED SHOWERS AND
THUNDERSTORMS DEVELOPED OVER THE HIGH COUNTRY AND ALONG THIS
BOUNDARY...WITH LIGHT RAINFALL LIKELY IN THE MOUNTAINS AND MORE
MODERATE RAINFALL RATES ACROSS THE PLAINS. MONSOONAL MOISTURE WILL
MOVE IN FOR MONDAY AND TUESDAY WITH HIGHER HUMIDITIES AND
INCREASED CHANCES FOR AFTERNOON AND EVENING THUNDERSTORMS. WARMER
AND DRIER WEATHER WILL PREVAIL FOR WEDNESDAY THROUGH FRIDAY.

&&

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

$$

SHORT TERM...RJM
LONG TERM...TJT
AVIATION...MAJ
FIRE WEATHER...RJM



000
FXUS65 KCYS 020441
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
1041 PM MDT SAT AUG 1 2015

.SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT)
ISSUED AT 344 PM MDT SAT AUG 1 2015

CONVECTION HAS DEVELOPED THIS AFTERNOON OFF THE HIGHER TERRAIN...IN
ADDITION TO THE SURFACE TROUGH THAT IS SITUATED ROUGHLY NEAR
CHEYENNE TO CHADRON NEBRASKA. MODERATE INSTABILITY IS IN PLACE
EAST OF THIS AREA WITH DEW POINTS IN THE LOW 50S TO LOW 60S UNDER
FAIRLY STEEP LAPSE RATES. ONE STORM IN SOUTHERN SIOUX COUNTY
PULSED VIGOROUSLY AT TIMES EARLIER THIS AFTERNOON...AND WOULD
EXPECT THIS TO BE THE TREND THROUGH THE REST OF THE AFTERNOON WITH
CONVECTION EAST OF THIS BOUNDARY. DEEP LAYER SHEAR ANALYSIS SHOWS
ROUGHLY 30-40 KTS IN PLACE...SO SOME ORGANIZATION OF CONVECTION IS
POSSIBLE BUT THE MAJORITY OF STORMS WILL REMAIN STRONG IN NATURE
WITH SOME HAIL...GUSTY WINDS AND MODERATE RAINFALL POSSIBLE OUT OF
THE STRONGER ACTIVITY. A WEAK WAVE APPROACHING FROM THE NORTHWEST
COULD KEEP A FEW STORMS GOING THROUGH SUNSET ALONG AND EAST OF THE
LARAMIE RANGE...ESPECIALLY IN AREAS OF OUTFLOW BOUNDARY
INTERACTION SO KEPT ISOLATED POPS FOR THESE AREAS THRU 03Z.
OTHERWISE TONIGHT SHOULD REMAIN DRY AND MILD.

THE SFC BOUNDARY WILL PUSH EAST TONIGHT AS THE WAVE MOVES
OVERHEAD...BUT YET ANOTHER SFC FRONT WILL DROP SOUTH ACROSS THE
PLAINS SUNDAY AFTERNOON. AT THE SAME TIME...A STRONGER SHORTWAVE
APPROACHING FROM THE SOUTHWEST WILL INDUCE STRONGER EAST-
SOUTHEASTERLY WINDS AT THE SFC AND LOW LEVEL MOISTURE ADVECTION
THROUGH THE DAY. THUS...WE ARE ONCE AGAIN EXPECTING ISOLATED
SHOWERS AND THUNDERSTORMS IN THE AFTERNOON FOR THE MOUNTAINS AND
THE WYOMING PLAINS AS THE FRONT PUSHES THROUGH AND WAVE APPROACHES
FROM THE SOUTHWEST. THAT SHORTWAVE WILL MOVE OVERHEAD ON
MONDAY...BRINGING WITH IT A MARKED INCREASE IN MONSOONAL MOISTURE.
PERHAPS WILL SEE SHOWERS/STORMS INITIATE EARLIER IN THE DAY AND
WITH A BROADER COVERAGE OF ACTIVITY ACROSS THE CWA. LOOKING AT
MODERATE TO HEAVY RAINFALL RATES FROM THIS ACTIVITY. WITH THE VERY
DRY ANTECEDENT CONDITIONS WEST OF THE LARAMIE RANGE AND ACROSS
CONVERSE/NIOBRARA COUNTIES...NOT ANTICIPATING ANY SIGNIFICANT
FLOODING ISSUES HERE. AREAS FURTHER SOUTH AND EAST...WILL HAVE TO
WATCH FOR THE POSSIBILITY OF FLASH FLOODING IN AREAS THAT SEE
HEAVIER RAINFALL OVER THE NEXT COUPLE OF DAYS WHICH COULD SATURATE
SOILS.

.LONG TERM...(TUESDAY THROUGH SATURDAY)
ISSUED AT 344 PM MDT SAT AUG 1 2015

MODELS ARE IN A LITTLE BETTER AGREEMENT TODAY IN THE LONG
TERM...BUT STILL STRUGGLING WITH THE TIMING OF SHORT WAVE ENERGY
EMBEDDED IN THE WEST TO NORTHWEST FLOW ALOFT. ALL MODELS NOW
INDICATE A FLATTER RIDGE COMPARED TO THE LAST FEW DAYS...WITH
WEAK SHORTWAVE DISTURBANCES MOVING ACROSS THE AREA. TUESDAY
APPEARS TO BE FAVORABLE FOR SCATTERED COVERAGE OF SHOWERS AND
TSTORMS THROUGH THE AFTERNOON OVER THE HIGH PLAINS...SO KEPT POP
ON THE HIGH SIDE ALONG AND EAST OF I25. THE GFS AND ECMWF SHOW A
PAIR OF STRONGER DISTURBANCES ON WEDNESDAY AND THURSDAY...AS A
COOL FRONT ACCELERATES SOUTHWARD ACROSS THE HIGH PLAINS BRINGING
COOLER TEMPERATURES TO THE REGION. KEPT POP LOW DURING THE
WEDNESDAY- THURSDAY TIME PERIOD BECAUSE OF THE TIMING OF THE FRONT
AND ASSOCIATED DISTURBANCE ALOFT...WHICH ALL MODELS SHOW MOVING
EAST OF THE FORECAST AREA BY THE AFTERNOON. THIS WOULD PUT MOST OF
SOUTHEAST WYOMING UNDER THE MID LEVEL SUBSIDENCE REGION BEHIND
THE TROUGH AXIS...WHICH IS NOT FAVORABLE FOR WIDESPREAD
CONVECTION. HOWEVER...THIS MAY CHANGE IN THE NEAR FUTURE IF MODEL
SOLUTIONS TREND A BIT MORE PROGRESSIVE. THE GFS AND ECMWF
SOLUTIONS ARE SIMILAR DURING THE MIDDLE OF THE WEEK...BUT THE
ECMWF IS FAR MORE WET...SHOWING LARGE AMOUNTS OF QPF EAST OF I25.

FOR LATE IN THE WEEK AND EARLY NEXT WEEKEND...MODELS ARE IN
REASONABLE AGREEMENT SHOWING AN UPPER LEVEL RIDGE AXIS MOVING
ACROSS THE FRONT RANGE...EXTENDING FROM COLORADO NORTHWARD INTO
SOUTHERN CANADA. ONCE THIS RIDGE AXIS PUSHES A BIT FURTHER
EAST...EXPECT A GREATER COVERAGE OF THUNDERSTORMS BY NEXT WEEKEND
AS SOME MONSOON MOISTURE BEGINS TO ADVECT NORTHWARD.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1032 PM MDT SAT AUG 1 2015

VFR CONDITIONS ARE FORECAST FOR SOUTHEAST WY AND WESTERN NE
PANHANDLE AERODROMES THROUGH SUNDAY. WINDS WILL BE LIGHT AND
VARIABLE THROUGH SUNDAY MORNING...THEN BECOMING EASTERLY. IT
WILL BE BREEZY AT TIMES WITH GUSTS TO 20 KT. ISOLATED AFTERNOON
TSTORMS WILL DEVELOP OVER THE MOUNTAINS AND ADJACENT SOUTHEAST WY
PLAINS SUNDAY...WITH THE CYS AND LAR AERODROMES POSSIBLY IMPACTED
AFTER 20Z.

&&

.FIRE WEATHER...
ISSUED AT 344 PM MDT SAT AUG 1 2015

HUMIDITIES HAVE DROPPED INTO THE LOW TO MID TEENS THIS AFTERNOON
WEST OF A LINE FROM CHEYENNE- CHADRON. A FEW GUSTS AROUND 20 MPH
ARE OCCURRING ACROSS THIS AREA AS WELL...WITH THE STRONGEST WINDS
IN THE NORTH SNOWY RANGE FOOTHILLS. ISOLATED SHOWERS AND
THUNDERSTORMS DEVELOPED OVER THE HIGH COUNTRY AND ALONG THIS
BOUNDARY...WITH LIGHT RAINFALL LIKELY IN THE MOUNTAINS AND MORE
MODERATE RAINFALL RATES ACROSS THE PLAINS. MONSOONAL MOISTURE WILL
MOVE IN FOR MONDAY AND TUESDAY WITH HIGHER HUMIDITIES AND
INCREASED CHANCES FOR AFTERNOON AND EVENING THUNDERSTORMS. WARMER
AND DRIER WEATHER WILL PREVAIL FOR WEDNESDAY THROUGH FRIDAY.

&&

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

$$

SHORT TERM...RJM
LONG TERM...TJT
AVIATION...MAJ
FIRE WEATHER...RJM



  [top]

000
FXUS63 KUNR 020235
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
835 PM MDT SAT AUG 1 2015

.UPDATE...
ISSUED AT 819 PM MDT SAT AUG 1 2015

UPPER LEVEL RIDGE BUILDING OVER WESTERN US WITH MONSOONAL MOISTURE
STREAMING NORTHWARD INTO WY. HOWEVER...NORTHWEST FLOW OVER
NORTHERN PLAINS WILL KEEP IT SOUTH OF FORECAST AREA. SOME HINTS OF
WEAK WAVES ON WATER VAPOR...BUT NOT STRONG ENOUGH TO GENERATE
STORMS. 00Z KUNR SOUNDING SHOWS STRONG CAP WITH DRY LAYER JUST OF
THE SURFACE...SO STORMS NOT EXPECTED OVERNIGHT. SURFACE BOUNDARY
IS ACROSS WESTERN ND-NORTHWESTERN SD WILL MOVE SOUTHEAST...
BRINGING DRY AIR INTO THE AREA SUNDAY.

&&

.SHORT TERM...THIS EVENING THROUGH SUNDAY NIGHT
ISSUED AT 247 PM MDT SAT AUG 1 2015

HOT AND DRY WEATHER CAN BE EXPECTED THROUGH THE REST OF THE
WEEKEND AS RIDGE GRADUALLY SLIDES ACROSS THE ROCKIES. HIGHS WILL
BE IN THE 90S ACROSS THE PLAINS...WITH 80S OVER THE BLACK HILLS.
NORTHERLY WINDS TONIGHT AND EARLY SUNDAY WILL GRADUALLY SHIFT OVER
TO THE EAST AND SOUTHEAST BY SUNDAY NIGHT AS HIGH PRESSURE SLIDES
NORTH AND EAST OF THE CWA.

.LONG TERM...MONDAY THROUGH SATURDAY
ISSUED AT 247 PM MDT SAT AUG 1 2015

MODELS IN DECENT AGREEMENT WITH THE OVERALL PATTERN THROUGH THE
WEEK. RIDGE BREAKS DOWN MONDAY/EARLY TUESDAY AS WEAK UPPER TROF
LIFTS THROUGH THE CENTRAL ROCKIES INTO THE PLAINS. EAST-SOUTHEAST
LOW LEVEL FLOW WILL BRING INCREASING BOUNDARY LAYER MOISTURE...
WHILE SURGE OF MID LEVEL MOISTURE ARRIVES WITH THE TROF. MAY BE A
FEW ISOLATED THUNDERSTORMS LATE MONDAY FROM THE BLACK HILLS INTO
SOUTH CENTRAL SOUTH DAKOTA. BETTER CHANCE OF THUNDERSTORMS ON
TUESDAY WITH WEAK UPPER TROF ACROSS THE NORTHERN PLAINS. WEAK
RIDGING ACROSS THE AREA FOR WEDNESDAY...THOUGH SUFFICIENT
INSTABILITY FOR A FEW THUNDERSTORMS. CHANCE OF STORMS WILL
CONTINUE THROUGH THE END OF THE WEEK AS UPPER TROF TRACKS ACROSS
THE PACIFIC NORTHWEST/NORTHERN ROCKIES.

&&

.AVIATION...FOR THE 06Z TAFS THROUGH 06Z SUNDAY EVENING
ISSUED AT 835 PM MDT SAT AUG 1 2015

ISOLD TSRA MAY DVLP OVR BLK HLS INTO SOUTH CNTRL SD...
OTHERWISE...SKIES WL BE CLR. NW WNDS WL DCRS THIS EVEN...THEN
INCRS AGAIN SUN.

&&

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

$$

UPDATE...55
SHORT TERM...26
LONG TERM...10
AVIATION...55



000
FXUS63 KUNR 020235
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
835 PM MDT SAT AUG 1 2015

.UPDATE...
ISSUED AT 819 PM MDT SAT AUG 1 2015

UPPER LEVEL RIDGE BUILDING OVER WESTERN US WITH MONSOONAL MOISTURE
STREAMING NORTHWARD INTO WY. HOWEVER...NORTHWEST FLOW OVER
NORTHERN PLAINS WILL KEEP IT SOUTH OF FORECAST AREA. SOME HINTS OF
WEAK WAVES ON WATER VAPOR...BUT NOT STRONG ENOUGH TO GENERATE
STORMS. 00Z KUNR SOUNDING SHOWS STRONG CAP WITH DRY LAYER JUST OF
THE SURFACE...SO STORMS NOT EXPECTED OVERNIGHT. SURFACE BOUNDARY
IS ACROSS WESTERN ND-NORTHWESTERN SD WILL MOVE SOUTHEAST...
BRINGING DRY AIR INTO THE AREA SUNDAY.

&&

.SHORT TERM...THIS EVENING THROUGH SUNDAY NIGHT
ISSUED AT 247 PM MDT SAT AUG 1 2015

HOT AND DRY WEATHER CAN BE EXPECTED THROUGH THE REST OF THE
WEEKEND AS RIDGE GRADUALLY SLIDES ACROSS THE ROCKIES. HIGHS WILL
BE IN THE 90S ACROSS THE PLAINS...WITH 80S OVER THE BLACK HILLS.
NORTHERLY WINDS TONIGHT AND EARLY SUNDAY WILL GRADUALLY SHIFT OVER
TO THE EAST AND SOUTHEAST BY SUNDAY NIGHT AS HIGH PRESSURE SLIDES
NORTH AND EAST OF THE CWA.

.LONG TERM...MONDAY THROUGH SATURDAY
ISSUED AT 247 PM MDT SAT AUG 1 2015

MODELS IN DECENT AGREEMENT WITH THE OVERALL PATTERN THROUGH THE
WEEK. RIDGE BREAKS DOWN MONDAY/EARLY TUESDAY AS WEAK UPPER TROF
LIFTS THROUGH THE CENTRAL ROCKIES INTO THE PLAINS. EAST-SOUTHEAST
LOW LEVEL FLOW WILL BRING INCREASING BOUNDARY LAYER MOISTURE...
WHILE SURGE OF MID LEVEL MOISTURE ARRIVES WITH THE TROF. MAY BE A
FEW ISOLATED THUNDERSTORMS LATE MONDAY FROM THE BLACK HILLS INTO
SOUTH CENTRAL SOUTH DAKOTA. BETTER CHANCE OF THUNDERSTORMS ON
TUESDAY WITH WEAK UPPER TROF ACROSS THE NORTHERN PLAINS. WEAK
RIDGING ACROSS THE AREA FOR WEDNESDAY...THOUGH SUFFICIENT
INSTABILITY FOR A FEW THUNDERSTORMS. CHANCE OF STORMS WILL
CONTINUE THROUGH THE END OF THE WEEK AS UPPER TROF TRACKS ACROSS
THE PACIFIC NORTHWEST/NORTHERN ROCKIES.

&&

.AVIATION...FOR THE 06Z TAFS THROUGH 06Z SUNDAY EVENING
ISSUED AT 835 PM MDT SAT AUG 1 2015

ISOLD TSRA MAY DVLP OVR BLK HLS INTO SOUTH CNTRL SD...
OTHERWISE...SKIES WL BE CLR. NW WNDS WL DCRS THIS EVEN...THEN
INCRS AGAIN SUN.

&&

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

$$

UPDATE...55
SHORT TERM...26
LONG TERM...10
AVIATION...55



000
FXUS63 KUNR 020235
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
835 PM MDT SAT AUG 1 2015

.UPDATE...
ISSUED AT 819 PM MDT SAT AUG 1 2015

UPPER LEVEL RIDGE BUILDING OVER WESTERN US WITH MONSOONAL MOISTURE
STREAMING NORTHWARD INTO WY. HOWEVER...NORTHWEST FLOW OVER
NORTHERN PLAINS WILL KEEP IT SOUTH OF FORECAST AREA. SOME HINTS OF
WEAK WAVES ON WATER VAPOR...BUT NOT STRONG ENOUGH TO GENERATE
STORMS. 00Z KUNR SOUNDING SHOWS STRONG CAP WITH DRY LAYER JUST OF
THE SURFACE...SO STORMS NOT EXPECTED OVERNIGHT. SURFACE BOUNDARY
IS ACROSS WESTERN ND-NORTHWESTERN SD WILL MOVE SOUTHEAST...
BRINGING DRY AIR INTO THE AREA SUNDAY.

&&

.SHORT TERM...THIS EVENING THROUGH SUNDAY NIGHT
ISSUED AT 247 PM MDT SAT AUG 1 2015

HOT AND DRY WEATHER CAN BE EXPECTED THROUGH THE REST OF THE
WEEKEND AS RIDGE GRADUALLY SLIDES ACROSS THE ROCKIES. HIGHS WILL
BE IN THE 90S ACROSS THE PLAINS...WITH 80S OVER THE BLACK HILLS.
NORTHERLY WINDS TONIGHT AND EARLY SUNDAY WILL GRADUALLY SHIFT OVER
TO THE EAST AND SOUTHEAST BY SUNDAY NIGHT AS HIGH PRESSURE SLIDES
NORTH AND EAST OF THE CWA.

.LONG TERM...MONDAY THROUGH SATURDAY
ISSUED AT 247 PM MDT SAT AUG 1 2015

MODELS IN DECENT AGREEMENT WITH THE OVERALL PATTERN THROUGH THE
WEEK. RIDGE BREAKS DOWN MONDAY/EARLY TUESDAY AS WEAK UPPER TROF
LIFTS THROUGH THE CENTRAL ROCKIES INTO THE PLAINS. EAST-SOUTHEAST
LOW LEVEL FLOW WILL BRING INCREASING BOUNDARY LAYER MOISTURE...
WHILE SURGE OF MID LEVEL MOISTURE ARRIVES WITH THE TROF. MAY BE A
FEW ISOLATED THUNDERSTORMS LATE MONDAY FROM THE BLACK HILLS INTO
SOUTH CENTRAL SOUTH DAKOTA. BETTER CHANCE OF THUNDERSTORMS ON
TUESDAY WITH WEAK UPPER TROF ACROSS THE NORTHERN PLAINS. WEAK
RIDGING ACROSS THE AREA FOR WEDNESDAY...THOUGH SUFFICIENT
INSTABILITY FOR A FEW THUNDERSTORMS. CHANCE OF STORMS WILL
CONTINUE THROUGH THE END OF THE WEEK AS UPPER TROF TRACKS ACROSS
THE PACIFIC NORTHWEST/NORTHERN ROCKIES.

&&

.AVIATION...FOR THE 06Z TAFS THROUGH 06Z SUNDAY EVENING
ISSUED AT 835 PM MDT SAT AUG 1 2015

ISOLD TSRA MAY DVLP OVR BLK HLS INTO SOUTH CNTRL SD...
OTHERWISE...SKIES WL BE CLR. NW WNDS WL DCRS THIS EVEN...THEN
INCRS AGAIN SUN.

&&

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

$$

UPDATE...55
SHORT TERM...26
LONG TERM...10
AVIATION...55



000
FXUS63 KUNR 020235
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
835 PM MDT SAT AUG 1 2015

.UPDATE...
ISSUED AT 819 PM MDT SAT AUG 1 2015

UPPER LEVEL RIDGE BUILDING OVER WESTERN US WITH MONSOONAL MOISTURE
STREAMING NORTHWARD INTO WY. HOWEVER...NORTHWEST FLOW OVER
NORTHERN PLAINS WILL KEEP IT SOUTH OF FORECAST AREA. SOME HINTS OF
WEAK WAVES ON WATER VAPOR...BUT NOT STRONG ENOUGH TO GENERATE
STORMS. 00Z KUNR SOUNDING SHOWS STRONG CAP WITH DRY LAYER JUST OF
THE SURFACE...SO STORMS NOT EXPECTED OVERNIGHT. SURFACE BOUNDARY
IS ACROSS WESTERN ND-NORTHWESTERN SD WILL MOVE SOUTHEAST...
BRINGING DRY AIR INTO THE AREA SUNDAY.

&&

.SHORT TERM...THIS EVENING THROUGH SUNDAY NIGHT
ISSUED AT 247 PM MDT SAT AUG 1 2015

HOT AND DRY WEATHER CAN BE EXPECTED THROUGH THE REST OF THE
WEEKEND AS RIDGE GRADUALLY SLIDES ACROSS THE ROCKIES. HIGHS WILL
BE IN THE 90S ACROSS THE PLAINS...WITH 80S OVER THE BLACK HILLS.
NORTHERLY WINDS TONIGHT AND EARLY SUNDAY WILL GRADUALLY SHIFT OVER
TO THE EAST AND SOUTHEAST BY SUNDAY NIGHT AS HIGH PRESSURE SLIDES
NORTH AND EAST OF THE CWA.

.LONG TERM...MONDAY THROUGH SATURDAY
ISSUED AT 247 PM MDT SAT AUG 1 2015

MODELS IN DECENT AGREEMENT WITH THE OVERALL PATTERN THROUGH THE
WEEK. RIDGE BREAKS DOWN MONDAY/EARLY TUESDAY AS WEAK UPPER TROF
LIFTS THROUGH THE CENTRAL ROCKIES INTO THE PLAINS. EAST-SOUTHEAST
LOW LEVEL FLOW WILL BRING INCREASING BOUNDARY LAYER MOISTURE...
WHILE SURGE OF MID LEVEL MOISTURE ARRIVES WITH THE TROF. MAY BE A
FEW ISOLATED THUNDERSTORMS LATE MONDAY FROM THE BLACK HILLS INTO
SOUTH CENTRAL SOUTH DAKOTA. BETTER CHANCE OF THUNDERSTORMS ON
TUESDAY WITH WEAK UPPER TROF ACROSS THE NORTHERN PLAINS. WEAK
RIDGING ACROSS THE AREA FOR WEDNESDAY...THOUGH SUFFICIENT
INSTABILITY FOR A FEW THUNDERSTORMS. CHANCE OF STORMS WILL
CONTINUE THROUGH THE END OF THE WEEK AS UPPER TROF TRACKS ACROSS
THE PACIFIC NORTHWEST/NORTHERN ROCKIES.

&&

.AVIATION...FOR THE 06Z TAFS THROUGH 06Z SUNDAY EVENING
ISSUED AT 835 PM MDT SAT AUG 1 2015

ISOLD TSRA MAY DVLP OVR BLK HLS INTO SOUTH CNTRL SD...
OTHERWISE...SKIES WL BE CLR. NW WNDS WL DCRS THIS EVEN...THEN
INCRS AGAIN SUN.

&&

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

$$

UPDATE...55
SHORT TERM...26
LONG TERM...10
AVIATION...55



000
FXUS65 KCYS 012345
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
545 PM MDT SAT AUG 1 2015

.SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT)
ISSUED AT 344 PM MDT SAT AUG 1 2015

CONVECTION HAS DEVELOPED THIS AFTERNOON OFF THE HIGHER TERRAIN...IN
ADDITION TO THE SURFACE TROUGH THAT IS SITUATED ROUGHLY NEAR
CHEYENNE TO CHADRON NEBRASKA. MODERATE INSTABILITY IS IN PLACE
EAST OF THIS AREA WITH DEW POINTS IN THE LOW 50S TO LOW 60S UNDER
FAIRLY STEEP LAPSE RATES. ONE STORM IN SOUTHERN SIOUX COUNTY
PULSED VIGOROUSLY AT TIMES EARLIER THIS AFTERNOON...AND WOULD
EXPECT THIS TO BE THE TREND THROUGH THE REST OF THE AFTERNOON WITH
CONVECTION EAST OF THIS BOUNDARY. DEEP LAYER SHEAR ANALYSIS SHOWS
ROUGHLY 30-40 KTS IN PLACE...SO SOME ORGANIZATION OF CONVECTION IS
POSSIBLE BUT THE MAJORITY OF STORMS WILL REMAIN PULSEY IN NATURE
WITH SOME HAIL...GUSTY WINDS AND MODERATE RAINFALL POSSIBLE OUT OF
THE STRONGER ACTIVITY. A WEAK WAVE APPROACHING FROM THE NORTHWEST
COULD KEEP A FEW STORMS GOING THROUGH SUNSET ALONG AND EAST OF THE
LARAMIE RANGE...ESPECIALLY IN AREAS OF OUTFLOW BOUNDARY
INTERACTION SO KEPT ISOLATED POPS FOR THESE AREAS THRU 03Z.
OTHERWISE TONIGHT SHOULD REMAIN DRY AND MILD.

THE SFC BOUNDARY WILL PUSH EAST TONIGHT AS THE WAVE MOVES
OVERHEAD...BUT YET ANOTHER SFC FRONT WILL DROP SOUTH ACROSS THE
PLAINS SUNDAY AFTERNOON. AT THE SAME TIME...A STRONGER SHORTWAVE
APPROACHING FROM THE SOUTHWEST WILL INDUCE STRONGER EAST-
SOUTHEASTERLY WINDS AT THE SFC AND LLVL MOISTURE ADVECTION THROUGH
THE DAY. THUS...WE ARE ONCE AGAIN EXPECTING ISOLATED SHOWERS AND
THUNDERSTORMS IN THE AFTERNOON FOR THE MOUNTAINS AND THE WYOMING
PLAINS AS THE FRONT PUSHES THROUGH AND WAVE APPROACHES FROM THE
SOUTHWEST. THAT SHORTWAVE WILL MOVE OVERHEAD ON MONDAY...BRINGING
WITH IT A MARKED INCREASE IN MONSOONAL MOISTURE. PERHAPS WILL SEE
SHOWERS/STORMS INITIATE EARLIER IN THE DAY AND WITH A BROADER
COVERAGE OF ACTIVITY ACROSS THE CWA. LOOKING AT MODERATE TO HEAVY
RAINFALL RATES FROM THIS ACTIVITY. WITH THE VERY DRY ANTECEDENT
CONDITIONSWEST OF THE LARAMIE RANGE AND ACROSS CONVERSE/NIOBRARA
COUNTIES...NOT ANTICIPATING ANY SIGNIFICANT FLOODING ISSUES HERE.
AREAS FURTHER SOUTH AND EAST...WILL HAVE TO WATCH FOR THE
POSSIBILITY OF FLASH FLOODING IN AREAS THAT SEE HEAVIER RAINFALL
OVER THE NEXT COUPLE OF DAYS WHICH COULD SATURATE SOILS.

.LONG TERM...(TUESDAY THROUGH SATURDAY)
ISSUED AT 344 PM MDT SAT AUG 1 2015

MODELS ARE IN A LITTLE BETTER AGREEMENT TODAY IN THE LONG
TERM...BUT STILL STRUGGLING WITH THE TIMING OF SHORT WAVE ENERGY
EMBEDDED IN THE WEST TO NORTHWEST FLOW ALOFT. ALL MODELS NOW
INDICATE A FLATTER RIDGE COMPARED TO THE LAST FEW DAYS...WITH
WEAK SHORTWAVE DISTURBANCES MOVING ACROSS THE AREA. TUESDAY
APPEARS TO BE FAVORABLE FOR SCATTERED COVERAGE OF SHOWERS AND
TSTORMS THROUGH THE AFTERNOON OVER THE HIGH PLAINS...SO KEPT POP
ON THE HIGH SIDE ALONG AND EAST OF I25. THE GFS AND ECMWF SHOW A
PAIR OF STRONGER DISTURBANCES ON WEDNESDAY AND THURSDAY...AS A
COOL FRONT ACCELERATES SOUTHWARD ACROSS THE HIGH PLAINS BRINGING
COOLER TEMPERATURES TO THE REGION. KEPT POP LOW DURING THE
WEDNESDAY- THURSDAY TIME PERIOD BECAUSE OF THE TIMING OF THE FRONT
AND ASSOCIATED DISTURBANCE ALOFT...WHICH ALL MODELS SHOW MOVING
EAST OF THE FORECAST AREA BY THE AFTERNOON. THIS WOULD PUT MOST OF
SOUTHEAST WYOMING UNDER THE MIDLEVEL SUBSIDENCE REGION BEHIND THE
TROUGH AXIS...WHICH IS NOT FAVORABLE FOR WIDESPREAD CONVECTION.
HOWEVER...THIS MAY CHANGE IN THE NEAR FUTURE IF MODEL SOLUTIONS
TREND A BIT MORE PROGRESSIVE. THE GFS AND ECMWF SOLUTIONS ARE
SIMILAR DURING THE MIDDLE OF THE WEEK...BUT THE ECMWF IS FAR MORE
WET...SHOWING LARGE AMOUNTS OF QPF EAST OF I25.

FOR LATE IN THE WEEK AND EARLY NEXT WEEKEND...MODELS ARE IN
REASONABLE AGREEMENT SHOWING AN UPPER LEVEL RIDGE AXIS MOVING
ACROSS THE FRONT RANGE...EXTENDING FROM COLORADO NORTHWARD INTO
SOUTHERN CANADA. ONCE THIS RIDGE AXIS PUSHES A BIT FURTHER
EAST...EXPECT A GREATER COVERAGE OF THUNDERSTORMS BY NEXT WEEKEND
AS SOME MONSOON MOISTURE BEGINS TO ADVECT NORTHWARD.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING)
ISSUED AT 545 PM MDT SAT AUG 1 2015

A FEW SHOWERS AND THUNDERSTORMS CONTINUE AT TAF ISSUANCE IN THE
SOUTHERN NEBRASKA PANHANDLE. EXPECT THIS ACTIVITY TO CONTINUE
THROUGH ABOUT 02Z WITH THE MAIN THREATS BEING GUSTY ERRATIC WINDS
AND MODERATE RAIN. GENERALLY CALM CONDITIONS WILL THEN OCCUR FOR
THE REST OF TONIGHT WITH WINDS BECOMING EAST-SOUTHEAST LATE
SUNDAY MORNING AND AFTERNOON. COULD BE A BIT GUSTY AT TIMES IN THE
AFTERNOON WITH ISOLATED SHOWERS AND THUNDERSTORMS DEVELOPING
MAINLY ALONG AND WEST OF I-25.

&&

.FIRE WEATHER...
ISSUED AT 344 PM MDT SAT AUG 1 2015

HUMIDITIES HAVE DROPPED INTO THE LOW TO MID TEENS THIS AFTERNOON
WEST OF A LINE FROM CHEYENNE-CHADRON. A FEW GUSTS AROUND 20 MPH ARE
OCCURRING ACROSS THIS AREA AS WELL...WITH THE STRONGEST WINDS IN THE
NORTH SNOWY RANGE FOOTHILLS. ISOLATED SHOWERS AND THUNDERSTORMS
DEVELOPED OVER THE HIGH COUNTRY AND ALONG THIS BOUNDARY...WITH LIGHT
RAINFALL LIKELY IN THE MOUNTAINS AND MORE MODERATE RAINFALL RATES
ACROSS THE PLAINS.  MONSOONAL MOISTURE WILL MOVE IN FOR MONDAY AND
TUESDAY WITH HIGHER HUMIDITIES AND INCREASED CHANCES FOR AFTERNOON
AND EVENING THUNDERSTORMS. WARMER AND DRIER WEATHER WILL PREVAIL FOR
WEDNESDAY THROUGH FRIDAY.

&&

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

$$

SHORT TERM...RJM
LONG TERM...TJT
AVIATION...RJM
FIRE WEATHER...RJM



000
FXUS65 KCYS 012345
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
545 PM MDT SAT AUG 1 2015

.SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT)
ISSUED AT 344 PM MDT SAT AUG 1 2015

CONVECTION HAS DEVELOPED THIS AFTERNOON OFF THE HIGHER TERRAIN...IN
ADDITION TO THE SURFACE TROUGH THAT IS SITUATED ROUGHLY NEAR
CHEYENNE TO CHADRON NEBRASKA. MODERATE INSTABILITY IS IN PLACE
EAST OF THIS AREA WITH DEW POINTS IN THE LOW 50S TO LOW 60S UNDER
FAIRLY STEEP LAPSE RATES. ONE STORM IN SOUTHERN SIOUX COUNTY
PULSED VIGOROUSLY AT TIMES EARLIER THIS AFTERNOON...AND WOULD
EXPECT THIS TO BE THE TREND THROUGH THE REST OF THE AFTERNOON WITH
CONVECTION EAST OF THIS BOUNDARY. DEEP LAYER SHEAR ANALYSIS SHOWS
ROUGHLY 30-40 KTS IN PLACE...SO SOME ORGANIZATION OF CONVECTION IS
POSSIBLE BUT THE MAJORITY OF STORMS WILL REMAIN PULSEY IN NATURE
WITH SOME HAIL...GUSTY WINDS AND MODERATE RAINFALL POSSIBLE OUT OF
THE STRONGER ACTIVITY. A WEAK WAVE APPROACHING FROM THE NORTHWEST
COULD KEEP A FEW STORMS GOING THROUGH SUNSET ALONG AND EAST OF THE
LARAMIE RANGE...ESPECIALLY IN AREAS OF OUTFLOW BOUNDARY
INTERACTION SO KEPT ISOLATED POPS FOR THESE AREAS THRU 03Z.
OTHERWISE TONIGHT SHOULD REMAIN DRY AND MILD.

THE SFC BOUNDARY WILL PUSH EAST TONIGHT AS THE WAVE MOVES
OVERHEAD...BUT YET ANOTHER SFC FRONT WILL DROP SOUTH ACROSS THE
PLAINS SUNDAY AFTERNOON. AT THE SAME TIME...A STRONGER SHORTWAVE
APPROACHING FROM THE SOUTHWEST WILL INDUCE STRONGER EAST-
SOUTHEASTERLY WINDS AT THE SFC AND LLVL MOISTURE ADVECTION THROUGH
THE DAY. THUS...WE ARE ONCE AGAIN EXPECTING ISOLATED SHOWERS AND
THUNDERSTORMS IN THE AFTERNOON FOR THE MOUNTAINS AND THE WYOMING
PLAINS AS THE FRONT PUSHES THROUGH AND WAVE APPROACHES FROM THE
SOUTHWEST. THAT SHORTWAVE WILL MOVE OVERHEAD ON MONDAY...BRINGING
WITH IT A MARKED INCREASE IN MONSOONAL MOISTURE. PERHAPS WILL SEE
SHOWERS/STORMS INITIATE EARLIER IN THE DAY AND WITH A BROADER
COVERAGE OF ACTIVITY ACROSS THE CWA. LOOKING AT MODERATE TO HEAVY
RAINFALL RATES FROM THIS ACTIVITY. WITH THE VERY DRY ANTECEDENT
CONDITIONSWEST OF THE LARAMIE RANGE AND ACROSS CONVERSE/NIOBRARA
COUNTIES...NOT ANTICIPATING ANY SIGNIFICANT FLOODING ISSUES HERE.
AREAS FURTHER SOUTH AND EAST...WILL HAVE TO WATCH FOR THE
POSSIBILITY OF FLASH FLOODING IN AREAS THAT SEE HEAVIER RAINFALL
OVER THE NEXT COUPLE OF DAYS WHICH COULD SATURATE SOILS.

.LONG TERM...(TUESDAY THROUGH SATURDAY)
ISSUED AT 344 PM MDT SAT AUG 1 2015

MODELS ARE IN A LITTLE BETTER AGREEMENT TODAY IN THE LONG
TERM...BUT STILL STRUGGLING WITH THE TIMING OF SHORT WAVE ENERGY
EMBEDDED IN THE WEST TO NORTHWEST FLOW ALOFT. ALL MODELS NOW
INDICATE A FLATTER RIDGE COMPARED TO THE LAST FEW DAYS...WITH
WEAK SHORTWAVE DISTURBANCES MOVING ACROSS THE AREA. TUESDAY
APPEARS TO BE FAVORABLE FOR SCATTERED COVERAGE OF SHOWERS AND
TSTORMS THROUGH THE AFTERNOON OVER THE HIGH PLAINS...SO KEPT POP
ON THE HIGH SIDE ALONG AND EAST OF I25. THE GFS AND ECMWF SHOW A
PAIR OF STRONGER DISTURBANCES ON WEDNESDAY AND THURSDAY...AS A
COOL FRONT ACCELERATES SOUTHWARD ACROSS THE HIGH PLAINS BRINGING
COOLER TEMPERATURES TO THE REGION. KEPT POP LOW DURING THE
WEDNESDAY- THURSDAY TIME PERIOD BECAUSE OF THE TIMING OF THE FRONT
AND ASSOCIATED DISTURBANCE ALOFT...WHICH ALL MODELS SHOW MOVING
EAST OF THE FORECAST AREA BY THE AFTERNOON. THIS WOULD PUT MOST OF
SOUTHEAST WYOMING UNDER THE MIDLEVEL SUBSIDENCE REGION BEHIND THE
TROUGH AXIS...WHICH IS NOT FAVORABLE FOR WIDESPREAD CONVECTION.
HOWEVER...THIS MAY CHANGE IN THE NEAR FUTURE IF MODEL SOLUTIONS
TREND A BIT MORE PROGRESSIVE. THE GFS AND ECMWF SOLUTIONS ARE
SIMILAR DURING THE MIDDLE OF THE WEEK...BUT THE ECMWF IS FAR MORE
WET...SHOWING LARGE AMOUNTS OF QPF EAST OF I25.

FOR LATE IN THE WEEK AND EARLY NEXT WEEKEND...MODELS ARE IN
REASONABLE AGREEMENT SHOWING AN UPPER LEVEL RIDGE AXIS MOVING
ACROSS THE FRONT RANGE...EXTENDING FROM COLORADO NORTHWARD INTO
SOUTHERN CANADA. ONCE THIS RIDGE AXIS PUSHES A BIT FURTHER
EAST...EXPECT A GREATER COVERAGE OF THUNDERSTORMS BY NEXT WEEKEND
AS SOME MONSOON MOISTURE BEGINS TO ADVECT NORTHWARD.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING)
ISSUED AT 545 PM MDT SAT AUG 1 2015

A FEW SHOWERS AND THUNDERSTORMS CONTINUE AT TAF ISSUANCE IN THE
SOUTHERN NEBRASKA PANHANDLE. EXPECT THIS ACTIVITY TO CONTINUE
THROUGH ABOUT 02Z WITH THE MAIN THREATS BEING GUSTY ERRATIC WINDS
AND MODERATE RAIN. GENERALLY CALM CONDITIONS WILL THEN OCCUR FOR
THE REST OF TONIGHT WITH WINDS BECOMING EAST-SOUTHEAST LATE
SUNDAY MORNING AND AFTERNOON. COULD BE A BIT GUSTY AT TIMES IN THE
AFTERNOON WITH ISOLATED SHOWERS AND THUNDERSTORMS DEVELOPING
MAINLY ALONG AND WEST OF I-25.

&&

.FIRE WEATHER...
ISSUED AT 344 PM MDT SAT AUG 1 2015

HUMIDITIES HAVE DROPPED INTO THE LOW TO MID TEENS THIS AFTERNOON
WEST OF A LINE FROM CHEYENNE-CHADRON. A FEW GUSTS AROUND 20 MPH ARE
OCCURRING ACROSS THIS AREA AS WELL...WITH THE STRONGEST WINDS IN THE
NORTH SNOWY RANGE FOOTHILLS. ISOLATED SHOWERS AND THUNDERSTORMS
DEVELOPED OVER THE HIGH COUNTRY AND ALONG THIS BOUNDARY...WITH LIGHT
RAINFALL LIKELY IN THE MOUNTAINS AND MORE MODERATE RAINFALL RATES
ACROSS THE PLAINS.  MONSOONAL MOISTURE WILL MOVE IN FOR MONDAY AND
TUESDAY WITH HIGHER HUMIDITIES AND INCREASED CHANCES FOR AFTERNOON
AND EVENING THUNDERSTORMS. WARMER AND DRIER WEATHER WILL PREVAIL FOR
WEDNESDAY THROUGH FRIDAY.

&&

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

$$

SHORT TERM...RJM
LONG TERM...TJT
AVIATION...RJM
FIRE WEATHER...RJM



000
FXUS65 KCYS 012345
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
545 PM MDT SAT AUG 1 2015

.SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT)
ISSUED AT 344 PM MDT SAT AUG 1 2015

CONVECTION HAS DEVELOPED THIS AFTERNOON OFF THE HIGHER TERRAIN...IN
ADDITION TO THE SURFACE TROUGH THAT IS SITUATED ROUGHLY NEAR
CHEYENNE TO CHADRON NEBRASKA. MODERATE INSTABILITY IS IN PLACE
EAST OF THIS AREA WITH DEW POINTS IN THE LOW 50S TO LOW 60S UNDER
FAIRLY STEEP LAPSE RATES. ONE STORM IN SOUTHERN SIOUX COUNTY
PULSED VIGOROUSLY AT TIMES EARLIER THIS AFTERNOON...AND WOULD
EXPECT THIS TO BE THE TREND THROUGH THE REST OF THE AFTERNOON WITH
CONVECTION EAST OF THIS BOUNDARY. DEEP LAYER SHEAR ANALYSIS SHOWS
ROUGHLY 30-40 KTS IN PLACE...SO SOME ORGANIZATION OF CONVECTION IS
POSSIBLE BUT THE MAJORITY OF STORMS WILL REMAIN PULSEY IN NATURE
WITH SOME HAIL...GUSTY WINDS AND MODERATE RAINFALL POSSIBLE OUT OF
THE STRONGER ACTIVITY. A WEAK WAVE APPROACHING FROM THE NORTHWEST
COULD KEEP A FEW STORMS GOING THROUGH SUNSET ALONG AND EAST OF THE
LARAMIE RANGE...ESPECIALLY IN AREAS OF OUTFLOW BOUNDARY
INTERACTION SO KEPT ISOLATED POPS FOR THESE AREAS THRU 03Z.
OTHERWISE TONIGHT SHOULD REMAIN DRY AND MILD.

THE SFC BOUNDARY WILL PUSH EAST TONIGHT AS THE WAVE MOVES
OVERHEAD...BUT YET ANOTHER SFC FRONT WILL DROP SOUTH ACROSS THE
PLAINS SUNDAY AFTERNOON. AT THE SAME TIME...A STRONGER SHORTWAVE
APPROACHING FROM THE SOUTHWEST WILL INDUCE STRONGER EAST-
SOUTHEASTERLY WINDS AT THE SFC AND LLVL MOISTURE ADVECTION THROUGH
THE DAY. THUS...WE ARE ONCE AGAIN EXPECTING ISOLATED SHOWERS AND
THUNDERSTORMS IN THE AFTERNOON FOR THE MOUNTAINS AND THE WYOMING
PLAINS AS THE FRONT PUSHES THROUGH AND WAVE APPROACHES FROM THE
SOUTHWEST. THAT SHORTWAVE WILL MOVE OVERHEAD ON MONDAY...BRINGING
WITH IT A MARKED INCREASE IN MONSOONAL MOISTURE. PERHAPS WILL SEE
SHOWERS/STORMS INITIATE EARLIER IN THE DAY AND WITH A BROADER
COVERAGE OF ACTIVITY ACROSS THE CWA. LOOKING AT MODERATE TO HEAVY
RAINFALL RATES FROM THIS ACTIVITY. WITH THE VERY DRY ANTECEDENT
CONDITIONSWEST OF THE LARAMIE RANGE AND ACROSS CONVERSE/NIOBRARA
COUNTIES...NOT ANTICIPATING ANY SIGNIFICANT FLOODING ISSUES HERE.
AREAS FURTHER SOUTH AND EAST...WILL HAVE TO WATCH FOR THE
POSSIBILITY OF FLASH FLOODING IN AREAS THAT SEE HEAVIER RAINFALL
OVER THE NEXT COUPLE OF DAYS WHICH COULD SATURATE SOILS.

.LONG TERM...(TUESDAY THROUGH SATURDAY)
ISSUED AT 344 PM MDT SAT AUG 1 2015

MODELS ARE IN A LITTLE BETTER AGREEMENT TODAY IN THE LONG
TERM...BUT STILL STRUGGLING WITH THE TIMING OF SHORT WAVE ENERGY
EMBEDDED IN THE WEST TO NORTHWEST FLOW ALOFT. ALL MODELS NOW
INDICATE A FLATTER RIDGE COMPARED TO THE LAST FEW DAYS...WITH
WEAK SHORTWAVE DISTURBANCES MOVING ACROSS THE AREA. TUESDAY
APPEARS TO BE FAVORABLE FOR SCATTERED COVERAGE OF SHOWERS AND
TSTORMS THROUGH THE AFTERNOON OVER THE HIGH PLAINS...SO KEPT POP
ON THE HIGH SIDE ALONG AND EAST OF I25. THE GFS AND ECMWF SHOW A
PAIR OF STRONGER DISTURBANCES ON WEDNESDAY AND THURSDAY...AS A
COOL FRONT ACCELERATES SOUTHWARD ACROSS THE HIGH PLAINS BRINGING
COOLER TEMPERATURES TO THE REGION. KEPT POP LOW DURING THE
WEDNESDAY- THURSDAY TIME PERIOD BECAUSE OF THE TIMING OF THE FRONT
AND ASSOCIATED DISTURBANCE ALOFT...WHICH ALL MODELS SHOW MOVING
EAST OF THE FORECAST AREA BY THE AFTERNOON. THIS WOULD PUT MOST OF
SOUTHEAST WYOMING UNDER THE MIDLEVEL SUBSIDENCE REGION BEHIND THE
TROUGH AXIS...WHICH IS NOT FAVORABLE FOR WIDESPREAD CONVECTION.
HOWEVER...THIS MAY CHANGE IN THE NEAR FUTURE IF MODEL SOLUTIONS
TREND A BIT MORE PROGRESSIVE. THE GFS AND ECMWF SOLUTIONS ARE
SIMILAR DURING THE MIDDLE OF THE WEEK...BUT THE ECMWF IS FAR MORE
WET...SHOWING LARGE AMOUNTS OF QPF EAST OF I25.

FOR LATE IN THE WEEK AND EARLY NEXT WEEKEND...MODELS ARE IN
REASONABLE AGREEMENT SHOWING AN UPPER LEVEL RIDGE AXIS MOVING
ACROSS THE FRONT RANGE...EXTENDING FROM COLORADO NORTHWARD INTO
SOUTHERN CANADA. ONCE THIS RIDGE AXIS PUSHES A BIT FURTHER
EAST...EXPECT A GREATER COVERAGE OF THUNDERSTORMS BY NEXT WEEKEND
AS SOME MONSOON MOISTURE BEGINS TO ADVECT NORTHWARD.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING)
ISSUED AT 545 PM MDT SAT AUG 1 2015

A FEW SHOWERS AND THUNDERSTORMS CONTINUE AT TAF ISSUANCE IN THE
SOUTHERN NEBRASKA PANHANDLE. EXPECT THIS ACTIVITY TO CONTINUE
THROUGH ABOUT 02Z WITH THE MAIN THREATS BEING GUSTY ERRATIC WINDS
AND MODERATE RAIN. GENERALLY CALM CONDITIONS WILL THEN OCCUR FOR
THE REST OF TONIGHT WITH WINDS BECOMING EAST-SOUTHEAST LATE
SUNDAY MORNING AND AFTERNOON. COULD BE A BIT GUSTY AT TIMES IN THE
AFTERNOON WITH ISOLATED SHOWERS AND THUNDERSTORMS DEVELOPING
MAINLY ALONG AND WEST OF I-25.

&&

.FIRE WEATHER...
ISSUED AT 344 PM MDT SAT AUG 1 2015

HUMIDITIES HAVE DROPPED INTO THE LOW TO MID TEENS THIS AFTERNOON
WEST OF A LINE FROM CHEYENNE-CHADRON. A FEW GUSTS AROUND 20 MPH ARE
OCCURRING ACROSS THIS AREA AS WELL...WITH THE STRONGEST WINDS IN THE
NORTH SNOWY RANGE FOOTHILLS. ISOLATED SHOWERS AND THUNDERSTORMS
DEVELOPED OVER THE HIGH COUNTRY AND ALONG THIS BOUNDARY...WITH LIGHT
RAINFALL LIKELY IN THE MOUNTAINS AND MORE MODERATE RAINFALL RATES
ACROSS THE PLAINS.  MONSOONAL MOISTURE WILL MOVE IN FOR MONDAY AND
TUESDAY WITH HIGHER HUMIDITIES AND INCREASED CHANCES FOR AFTERNOON
AND EVENING THUNDERSTORMS. WARMER AND DRIER WEATHER WILL PREVAIL FOR
WEDNESDAY THROUGH FRIDAY.

&&

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

$$

SHORT TERM...RJM
LONG TERM...TJT
AVIATION...RJM
FIRE WEATHER...RJM



000
FXUS65 KCYS 012345
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
545 PM MDT SAT AUG 1 2015

.SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT)
ISSUED AT 344 PM MDT SAT AUG 1 2015

CONVECTION HAS DEVELOPED THIS AFTERNOON OFF THE HIGHER TERRAIN...IN
ADDITION TO THE SURFACE TROUGH THAT IS SITUATED ROUGHLY NEAR
CHEYENNE TO CHADRON NEBRASKA. MODERATE INSTABILITY IS IN PLACE
EAST OF THIS AREA WITH DEW POINTS IN THE LOW 50S TO LOW 60S UNDER
FAIRLY STEEP LAPSE RATES. ONE STORM IN SOUTHERN SIOUX COUNTY
PULSED VIGOROUSLY AT TIMES EARLIER THIS AFTERNOON...AND WOULD
EXPECT THIS TO BE THE TREND THROUGH THE REST OF THE AFTERNOON WITH
CONVECTION EAST OF THIS BOUNDARY. DEEP LAYER SHEAR ANALYSIS SHOWS
ROUGHLY 30-40 KTS IN PLACE...SO SOME ORGANIZATION OF CONVECTION IS
POSSIBLE BUT THE MAJORITY OF STORMS WILL REMAIN PULSEY IN NATURE
WITH SOME HAIL...GUSTY WINDS AND MODERATE RAINFALL POSSIBLE OUT OF
THE STRONGER ACTIVITY. A WEAK WAVE APPROACHING FROM THE NORTHWEST
COULD KEEP A FEW STORMS GOING THROUGH SUNSET ALONG AND EAST OF THE
LARAMIE RANGE...ESPECIALLY IN AREAS OF OUTFLOW BOUNDARY
INTERACTION SO KEPT ISOLATED POPS FOR THESE AREAS THRU 03Z.
OTHERWISE TONIGHT SHOULD REMAIN DRY AND MILD.

THE SFC BOUNDARY WILL PUSH EAST TONIGHT AS THE WAVE MOVES
OVERHEAD...BUT YET ANOTHER SFC FRONT WILL DROP SOUTH ACROSS THE
PLAINS SUNDAY AFTERNOON. AT THE SAME TIME...A STRONGER SHORTWAVE
APPROACHING FROM THE SOUTHWEST WILL INDUCE STRONGER EAST-
SOUTHEASTERLY WINDS AT THE SFC AND LLVL MOISTURE ADVECTION THROUGH
THE DAY. THUS...WE ARE ONCE AGAIN EXPECTING ISOLATED SHOWERS AND
THUNDERSTORMS IN THE AFTERNOON FOR THE MOUNTAINS AND THE WYOMING
PLAINS AS THE FRONT PUSHES THROUGH AND WAVE APPROACHES FROM THE
SOUTHWEST. THAT SHORTWAVE WILL MOVE OVERHEAD ON MONDAY...BRINGING
WITH IT A MARKED INCREASE IN MONSOONAL MOISTURE. PERHAPS WILL SEE
SHOWERS/STORMS INITIATE EARLIER IN THE DAY AND WITH A BROADER
COVERAGE OF ACTIVITY ACROSS THE CWA. LOOKING AT MODERATE TO HEAVY
RAINFALL RATES FROM THIS ACTIVITY. WITH THE VERY DRY ANTECEDENT
CONDITIONSWEST OF THE LARAMIE RANGE AND ACROSS CONVERSE/NIOBRARA
COUNTIES...NOT ANTICIPATING ANY SIGNIFICANT FLOODING ISSUES HERE.
AREAS FURTHER SOUTH AND EAST...WILL HAVE TO WATCH FOR THE
POSSIBILITY OF FLASH FLOODING IN AREAS THAT SEE HEAVIER RAINFALL
OVER THE NEXT COUPLE OF DAYS WHICH COULD SATURATE SOILS.

.LONG TERM...(TUESDAY THROUGH SATURDAY)
ISSUED AT 344 PM MDT SAT AUG 1 2015

MODELS ARE IN A LITTLE BETTER AGREEMENT TODAY IN THE LONG
TERM...BUT STILL STRUGGLING WITH THE TIMING OF SHORT WAVE ENERGY
EMBEDDED IN THE WEST TO NORTHWEST FLOW ALOFT. ALL MODELS NOW
INDICATE A FLATTER RIDGE COMPARED TO THE LAST FEW DAYS...WITH
WEAK SHORTWAVE DISTURBANCES MOVING ACROSS THE AREA. TUESDAY
APPEARS TO BE FAVORABLE FOR SCATTERED COVERAGE OF SHOWERS AND
TSTORMS THROUGH THE AFTERNOON OVER THE HIGH PLAINS...SO KEPT POP
ON THE HIGH SIDE ALONG AND EAST OF I25. THE GFS AND ECMWF SHOW A
PAIR OF STRONGER DISTURBANCES ON WEDNESDAY AND THURSDAY...AS A
COOL FRONT ACCELERATES SOUTHWARD ACROSS THE HIGH PLAINS BRINGING
COOLER TEMPERATURES TO THE REGION. KEPT POP LOW DURING THE
WEDNESDAY- THURSDAY TIME PERIOD BECAUSE OF THE TIMING OF THE FRONT
AND ASSOCIATED DISTURBANCE ALOFT...WHICH ALL MODELS SHOW MOVING
EAST OF THE FORECAST AREA BY THE AFTERNOON. THIS WOULD PUT MOST OF
SOUTHEAST WYOMING UNDER THE MIDLEVEL SUBSIDENCE REGION BEHIND THE
TROUGH AXIS...WHICH IS NOT FAVORABLE FOR WIDESPREAD CONVECTION.
HOWEVER...THIS MAY CHANGE IN THE NEAR FUTURE IF MODEL SOLUTIONS
TREND A BIT MORE PROGRESSIVE. THE GFS AND ECMWF SOLUTIONS ARE
SIMILAR DURING THE MIDDLE OF THE WEEK...BUT THE ECMWF IS FAR MORE
WET...SHOWING LARGE AMOUNTS OF QPF EAST OF I25.

FOR LATE IN THE WEEK AND EARLY NEXT WEEKEND...MODELS ARE IN
REASONABLE AGREEMENT SHOWING AN UPPER LEVEL RIDGE AXIS MOVING
ACROSS THE FRONT RANGE...EXTENDING FROM COLORADO NORTHWARD INTO
SOUTHERN CANADA. ONCE THIS RIDGE AXIS PUSHES A BIT FURTHER
EAST...EXPECT A GREATER COVERAGE OF THUNDERSTORMS BY NEXT WEEKEND
AS SOME MONSOON MOISTURE BEGINS TO ADVECT NORTHWARD.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING)
ISSUED AT 545 PM MDT SAT AUG 1 2015

A FEW SHOWERS AND THUNDERSTORMS CONTINUE AT TAF ISSUANCE IN THE
SOUTHERN NEBRASKA PANHANDLE. EXPECT THIS ACTIVITY TO CONTINUE
THROUGH ABOUT 02Z WITH THE MAIN THREATS BEING GUSTY ERRATIC WINDS
AND MODERATE RAIN. GENERALLY CALM CONDITIONS WILL THEN OCCUR FOR
THE REST OF TONIGHT WITH WINDS BECOMING EAST-SOUTHEAST LATE
SUNDAY MORNING AND AFTERNOON. COULD BE A BIT GUSTY AT TIMES IN THE
AFTERNOON WITH ISOLATED SHOWERS AND THUNDERSTORMS DEVELOPING
MAINLY ALONG AND WEST OF I-25.

&&

.FIRE WEATHER...
ISSUED AT 344 PM MDT SAT AUG 1 2015

HUMIDITIES HAVE DROPPED INTO THE LOW TO MID TEENS THIS AFTERNOON
WEST OF A LINE FROM CHEYENNE-CHADRON. A FEW GUSTS AROUND 20 MPH ARE
OCCURRING ACROSS THIS AREA AS WELL...WITH THE STRONGEST WINDS IN THE
NORTH SNOWY RANGE FOOTHILLS. ISOLATED SHOWERS AND THUNDERSTORMS
DEVELOPED OVER THE HIGH COUNTRY AND ALONG THIS BOUNDARY...WITH LIGHT
RAINFALL LIKELY IN THE MOUNTAINS AND MORE MODERATE RAINFALL RATES
ACROSS THE PLAINS.  MONSOONAL MOISTURE WILL MOVE IN FOR MONDAY AND
TUESDAY WITH HIGHER HUMIDITIES AND INCREASED CHANCES FOR AFTERNOON
AND EVENING THUNDERSTORMS. WARMER AND DRIER WEATHER WILL PREVAIL FOR
WEDNESDAY THROUGH FRIDAY.

&&

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

$$

SHORT TERM...RJM
LONG TERM...TJT
AVIATION...RJM
FIRE WEATHER...RJM



000
FXUS65 KCYS 012345
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
545 PM MDT SAT AUG 1 2015

.SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT)
ISSUED AT 344 PM MDT SAT AUG 1 2015

CONVECTION HAS DEVELOPED THIS AFTERNOON OFF THE HIGHER TERRAIN...IN
ADDITION TO THE SURFACE TROUGH THAT IS SITUATED ROUGHLY NEAR
CHEYENNE TO CHADRON NEBRASKA. MODERATE INSTABILITY IS IN PLACE
EAST OF THIS AREA WITH DEW POINTS IN THE LOW 50S TO LOW 60S UNDER
FAIRLY STEEP LAPSE RATES. ONE STORM IN SOUTHERN SIOUX COUNTY
PULSED VIGOROUSLY AT TIMES EARLIER THIS AFTERNOON...AND WOULD
EXPECT THIS TO BE THE TREND THROUGH THE REST OF THE AFTERNOON WITH
CONVECTION EAST OF THIS BOUNDARY. DEEP LAYER SHEAR ANALYSIS SHOWS
ROUGHLY 30-40 KTS IN PLACE...SO SOME ORGANIZATION OF CONVECTION IS
POSSIBLE BUT THE MAJORITY OF STORMS WILL REMAIN PULSEY IN NATURE
WITH SOME HAIL...GUSTY WINDS AND MODERATE RAINFALL POSSIBLE OUT OF
THE STRONGER ACTIVITY. A WEAK WAVE APPROACHING FROM THE NORTHWEST
COULD KEEP A FEW STORMS GOING THROUGH SUNSET ALONG AND EAST OF THE
LARAMIE RANGE...ESPECIALLY IN AREAS OF OUTFLOW BOUNDARY
INTERACTION SO KEPT ISOLATED POPS FOR THESE AREAS THRU 03Z.
OTHERWISE TONIGHT SHOULD REMAIN DRY AND MILD.

THE SFC BOUNDARY WILL PUSH EAST TONIGHT AS THE WAVE MOVES
OVERHEAD...BUT YET ANOTHER SFC FRONT WILL DROP SOUTH ACROSS THE
PLAINS SUNDAY AFTERNOON. AT THE SAME TIME...A STRONGER SHORTWAVE
APPROACHING FROM THE SOUTHWEST WILL INDUCE STRONGER EAST-
SOUTHEASTERLY WINDS AT THE SFC AND LLVL MOISTURE ADVECTION THROUGH
THE DAY. THUS...WE ARE ONCE AGAIN EXPECTING ISOLATED SHOWERS AND
THUNDERSTORMS IN THE AFTERNOON FOR THE MOUNTAINS AND THE WYOMING
PLAINS AS THE FRONT PUSHES THROUGH AND WAVE APPROACHES FROM THE
SOUTHWEST. THAT SHORTWAVE WILL MOVE OVERHEAD ON MONDAY...BRINGING
WITH IT A MARKED INCREASE IN MONSOONAL MOISTURE. PERHAPS WILL SEE
SHOWERS/STORMS INITIATE EARLIER IN THE DAY AND WITH A BROADER
COVERAGE OF ACTIVITY ACROSS THE CWA. LOOKING AT MODERATE TO HEAVY
RAINFALL RATES FROM THIS ACTIVITY. WITH THE VERY DRY ANTECEDENT
CONDITIONSWEST OF THE LARAMIE RANGE AND ACROSS CONVERSE/NIOBRARA
COUNTIES...NOT ANTICIPATING ANY SIGNIFICANT FLOODING ISSUES HERE.
AREAS FURTHER SOUTH AND EAST...WILL HAVE TO WATCH FOR THE
POSSIBILITY OF FLASH FLOODING IN AREAS THAT SEE HEAVIER RAINFALL
OVER THE NEXT COUPLE OF DAYS WHICH COULD SATURATE SOILS.

.LONG TERM...(TUESDAY THROUGH SATURDAY)
ISSUED AT 344 PM MDT SAT AUG 1 2015

MODELS ARE IN A LITTLE BETTER AGREEMENT TODAY IN THE LONG
TERM...BUT STILL STRUGGLING WITH THE TIMING OF SHORT WAVE ENERGY
EMBEDDED IN THE WEST TO NORTHWEST FLOW ALOFT. ALL MODELS NOW
INDICATE A FLATTER RIDGE COMPARED TO THE LAST FEW DAYS...WITH
WEAK SHORTWAVE DISTURBANCES MOVING ACROSS THE AREA. TUESDAY
APPEARS TO BE FAVORABLE FOR SCATTERED COVERAGE OF SHOWERS AND
TSTORMS THROUGH THE AFTERNOON OVER THE HIGH PLAINS...SO KEPT POP
ON THE HIGH SIDE ALONG AND EAST OF I25. THE GFS AND ECMWF SHOW A
PAIR OF STRONGER DISTURBANCES ON WEDNESDAY AND THURSDAY...AS A
COOL FRONT ACCELERATES SOUTHWARD ACROSS THE HIGH PLAINS BRINGING
COOLER TEMPERATURES TO THE REGION. KEPT POP LOW DURING THE
WEDNESDAY- THURSDAY TIME PERIOD BECAUSE OF THE TIMING OF THE FRONT
AND ASSOCIATED DISTURBANCE ALOFT...WHICH ALL MODELS SHOW MOVING
EAST OF THE FORECAST AREA BY THE AFTERNOON. THIS WOULD PUT MOST OF
SOUTHEAST WYOMING UNDER THE MIDLEVEL SUBSIDENCE REGION BEHIND THE
TROUGH AXIS...WHICH IS NOT FAVORABLE FOR WIDESPREAD CONVECTION.
HOWEVER...THIS MAY CHANGE IN THE NEAR FUTURE IF MODEL SOLUTIONS
TREND A BIT MORE PROGRESSIVE. THE GFS AND ECMWF SOLUTIONS ARE
SIMILAR DURING THE MIDDLE OF THE WEEK...BUT THE ECMWF IS FAR MORE
WET...SHOWING LARGE AMOUNTS OF QPF EAST OF I25.

FOR LATE IN THE WEEK AND EARLY NEXT WEEKEND...MODELS ARE IN
REASONABLE AGREEMENT SHOWING AN UPPER LEVEL RIDGE AXIS MOVING
ACROSS THE FRONT RANGE...EXTENDING FROM COLORADO NORTHWARD INTO
SOUTHERN CANADA. ONCE THIS RIDGE AXIS PUSHES A BIT FURTHER
EAST...EXPECT A GREATER COVERAGE OF THUNDERSTORMS BY NEXT WEEKEND
AS SOME MONSOON MOISTURE BEGINS TO ADVECT NORTHWARD.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING)
ISSUED AT 545 PM MDT SAT AUG 1 2015

A FEW SHOWERS AND THUNDERSTORMS CONTINUE AT TAF ISSUANCE IN THE
SOUTHERN NEBRASKA PANHANDLE. EXPECT THIS ACTIVITY TO CONTINUE
THROUGH ABOUT 02Z WITH THE MAIN THREATS BEING GUSTY ERRATIC WINDS
AND MODERATE RAIN. GENERALLY CALM CONDITIONS WILL THEN OCCUR FOR
THE REST OF TONIGHT WITH WINDS BECOMING EAST-SOUTHEAST LATE
SUNDAY MORNING AND AFTERNOON. COULD BE A BIT GUSTY AT TIMES IN THE
AFTERNOON WITH ISOLATED SHOWERS AND THUNDERSTORMS DEVELOPING
MAINLY ALONG AND WEST OF I-25.

&&

.FIRE WEATHER...
ISSUED AT 344 PM MDT SAT AUG 1 2015

HUMIDITIES HAVE DROPPED INTO THE LOW TO MID TEENS THIS AFTERNOON
WEST OF A LINE FROM CHEYENNE-CHADRON. A FEW GUSTS AROUND 20 MPH ARE
OCCURRING ACROSS THIS AREA AS WELL...WITH THE STRONGEST WINDS IN THE
NORTH SNOWY RANGE FOOTHILLS. ISOLATED SHOWERS AND THUNDERSTORMS
DEVELOPED OVER THE HIGH COUNTRY AND ALONG THIS BOUNDARY...WITH LIGHT
RAINFALL LIKELY IN THE MOUNTAINS AND MORE MODERATE RAINFALL RATES
ACROSS THE PLAINS.  MONSOONAL MOISTURE WILL MOVE IN FOR MONDAY AND
TUESDAY WITH HIGHER HUMIDITIES AND INCREASED CHANCES FOR AFTERNOON
AND EVENING THUNDERSTORMS. WARMER AND DRIER WEATHER WILL PREVAIL FOR
WEDNESDAY THROUGH FRIDAY.

&&

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

$$

SHORT TERM...RJM
LONG TERM...TJT
AVIATION...RJM
FIRE WEATHER...RJM



000
FXUS65 KCYS 012345
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
545 PM MDT SAT AUG 1 2015

.SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT)
ISSUED AT 344 PM MDT SAT AUG 1 2015

CONVECTION HAS DEVELOPED THIS AFTERNOON OFF THE HIGHER TERRAIN...IN
ADDITION TO THE SURFACE TROUGH THAT IS SITUATED ROUGHLY NEAR
CHEYENNE TO CHADRON NEBRASKA. MODERATE INSTABILITY IS IN PLACE
EAST OF THIS AREA WITH DEW POINTS IN THE LOW 50S TO LOW 60S UNDER
FAIRLY STEEP LAPSE RATES. ONE STORM IN SOUTHERN SIOUX COUNTY
PULSED VIGOROUSLY AT TIMES EARLIER THIS AFTERNOON...AND WOULD
EXPECT THIS TO BE THE TREND THROUGH THE REST OF THE AFTERNOON WITH
CONVECTION EAST OF THIS BOUNDARY. DEEP LAYER SHEAR ANALYSIS SHOWS
ROUGHLY 30-40 KTS IN PLACE...SO SOME ORGANIZATION OF CONVECTION IS
POSSIBLE BUT THE MAJORITY OF STORMS WILL REMAIN PULSEY IN NATURE
WITH SOME HAIL...GUSTY WINDS AND MODERATE RAINFALL POSSIBLE OUT OF
THE STRONGER ACTIVITY. A WEAK WAVE APPROACHING FROM THE NORTHWEST
COULD KEEP A FEW STORMS GOING THROUGH SUNSET ALONG AND EAST OF THE
LARAMIE RANGE...ESPECIALLY IN AREAS OF OUTFLOW BOUNDARY
INTERACTION SO KEPT ISOLATED POPS FOR THESE AREAS THRU 03Z.
OTHERWISE TONIGHT SHOULD REMAIN DRY AND MILD.

THE SFC BOUNDARY WILL PUSH EAST TONIGHT AS THE WAVE MOVES
OVERHEAD...BUT YET ANOTHER SFC FRONT WILL DROP SOUTH ACROSS THE
PLAINS SUNDAY AFTERNOON. AT THE SAME TIME...A STRONGER SHORTWAVE
APPROACHING FROM THE SOUTHWEST WILL INDUCE STRONGER EAST-
SOUTHEASTERLY WINDS AT THE SFC AND LLVL MOISTURE ADVECTION THROUGH
THE DAY. THUS...WE ARE ONCE AGAIN EXPECTING ISOLATED SHOWERS AND
THUNDERSTORMS IN THE AFTERNOON FOR THE MOUNTAINS AND THE WYOMING
PLAINS AS THE FRONT PUSHES THROUGH AND WAVE APPROACHES FROM THE
SOUTHWEST. THAT SHORTWAVE WILL MOVE OVERHEAD ON MONDAY...BRINGING
WITH IT A MARKED INCREASE IN MONSOONAL MOISTURE. PERHAPS WILL SEE
SHOWERS/STORMS INITIATE EARLIER IN THE DAY AND WITH A BROADER
COVERAGE OF ACTIVITY ACROSS THE CWA. LOOKING AT MODERATE TO HEAVY
RAINFALL RATES FROM THIS ACTIVITY. WITH THE VERY DRY ANTECEDENT
CONDITIONSWEST OF THE LARAMIE RANGE AND ACROSS CONVERSE/NIOBRARA
COUNTIES...NOT ANTICIPATING ANY SIGNIFICANT FLOODING ISSUES HERE.
AREAS FURTHER SOUTH AND EAST...WILL HAVE TO WATCH FOR THE
POSSIBILITY OF FLASH FLOODING IN AREAS THAT SEE HEAVIER RAINFALL
OVER THE NEXT COUPLE OF DAYS WHICH COULD SATURATE SOILS.

.LONG TERM...(TUESDAY THROUGH SATURDAY)
ISSUED AT 344 PM MDT SAT AUG 1 2015

MODELS ARE IN A LITTLE BETTER AGREEMENT TODAY IN THE LONG
TERM...BUT STILL STRUGGLING WITH THE TIMING OF SHORT WAVE ENERGY
EMBEDDED IN THE WEST TO NORTHWEST FLOW ALOFT. ALL MODELS NOW
INDICATE A FLATTER RIDGE COMPARED TO THE LAST FEW DAYS...WITH
WEAK SHORTWAVE DISTURBANCES MOVING ACROSS THE AREA. TUESDAY
APPEARS TO BE FAVORABLE FOR SCATTERED COVERAGE OF SHOWERS AND
TSTORMS THROUGH THE AFTERNOON OVER THE HIGH PLAINS...SO KEPT POP
ON THE HIGH SIDE ALONG AND EAST OF I25. THE GFS AND ECMWF SHOW A
PAIR OF STRONGER DISTURBANCES ON WEDNESDAY AND THURSDAY...AS A
COOL FRONT ACCELERATES SOUTHWARD ACROSS THE HIGH PLAINS BRINGING
COOLER TEMPERATURES TO THE REGION. KEPT POP LOW DURING THE
WEDNESDAY- THURSDAY TIME PERIOD BECAUSE OF THE TIMING OF THE FRONT
AND ASSOCIATED DISTURBANCE ALOFT...WHICH ALL MODELS SHOW MOVING
EAST OF THE FORECAST AREA BY THE AFTERNOON. THIS WOULD PUT MOST OF
SOUTHEAST WYOMING UNDER THE MIDLEVEL SUBSIDENCE REGION BEHIND THE
TROUGH AXIS...WHICH IS NOT FAVORABLE FOR WIDESPREAD CONVECTION.
HOWEVER...THIS MAY CHANGE IN THE NEAR FUTURE IF MODEL SOLUTIONS
TREND A BIT MORE PROGRESSIVE. THE GFS AND ECMWF SOLUTIONS ARE
SIMILAR DURING THE MIDDLE OF THE WEEK...BUT THE ECMWF IS FAR MORE
WET...SHOWING LARGE AMOUNTS OF QPF EAST OF I25.

FOR LATE IN THE WEEK AND EARLY NEXT WEEKEND...MODELS ARE IN
REASONABLE AGREEMENT SHOWING AN UPPER LEVEL RIDGE AXIS MOVING
ACROSS THE FRONT RANGE...EXTENDING FROM COLORADO NORTHWARD INTO
SOUTHERN CANADA. ONCE THIS RIDGE AXIS PUSHES A BIT FURTHER
EAST...EXPECT A GREATER COVERAGE OF THUNDERSTORMS BY NEXT WEEKEND
AS SOME MONSOON MOISTURE BEGINS TO ADVECT NORTHWARD.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING)
ISSUED AT 545 PM MDT SAT AUG 1 2015

A FEW SHOWERS AND THUNDERSTORMS CONTINUE AT TAF ISSUANCE IN THE
SOUTHERN NEBRASKA PANHANDLE. EXPECT THIS ACTIVITY TO CONTINUE
THROUGH ABOUT 02Z WITH THE MAIN THREATS BEING GUSTY ERRATIC WINDS
AND MODERATE RAIN. GENERALLY CALM CONDITIONS WILL THEN OCCUR FOR
THE REST OF TONIGHT WITH WINDS BECOMING EAST-SOUTHEAST LATE
SUNDAY MORNING AND AFTERNOON. COULD BE A BIT GUSTY AT TIMES IN THE
AFTERNOON WITH ISOLATED SHOWERS AND THUNDERSTORMS DEVELOPING
MAINLY ALONG AND WEST OF I-25.

&&

.FIRE WEATHER...
ISSUED AT 344 PM MDT SAT AUG 1 2015

HUMIDITIES HAVE DROPPED INTO THE LOW TO MID TEENS THIS AFTERNOON
WEST OF A LINE FROM CHEYENNE-CHADRON. A FEW GUSTS AROUND 20 MPH ARE
OCCURRING ACROSS THIS AREA AS WELL...WITH THE STRONGEST WINDS IN THE
NORTH SNOWY RANGE FOOTHILLS. ISOLATED SHOWERS AND THUNDERSTORMS
DEVELOPED OVER THE HIGH COUNTRY AND ALONG THIS BOUNDARY...WITH LIGHT
RAINFALL LIKELY IN THE MOUNTAINS AND MORE MODERATE RAINFALL RATES
ACROSS THE PLAINS.  MONSOONAL MOISTURE WILL MOVE IN FOR MONDAY AND
TUESDAY WITH HIGHER HUMIDITIES AND INCREASED CHANCES FOR AFTERNOON
AND EVENING THUNDERSTORMS. WARMER AND DRIER WEATHER WILL PREVAIL FOR
WEDNESDAY THROUGH FRIDAY.

&&

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

$$

SHORT TERM...RJM
LONG TERM...TJT
AVIATION...RJM
FIRE WEATHER...RJM




000
FXUS63 KUNR 012337
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
537 PM MDT SAT AUG 1 2015

.SHORT TERM...THIS EVENING THROUGH SUNDAY NIGHT
ISSUED AT 247 PM MDT SAT AUG 1 2015

CURRENT SURFACE ANALYSIS SHOWS FRONTAL BOUNDARY/WARM FRONT NOW
STRETCHING FROM NORTHEAST MT TO EASTERN SD...WITH A SURFACE TROF
EXTENDING SOUTHWARD ACROSS CENTRAL SD. UPPER LEVEL ANALYSIS
CONTINUES TO SHOW RIDGE OVER THE WESTERN CONUS...WITH
NORTHWESTERLY FLOW OVER THE NORTHERN PLAINS. TEMPS ARE MOSTLY IN
THE 90S NOW ACROSS THE PLAINS...WITH 80S IN THE HILLS. WEAK
SHORTWAVE ENERGY WITH SHOWERS AND STORMS HAS MOVED SOUTH OF THE
CWA. HOWEVER...A COUPLE OF SHOWERS AND THUNDERSTORMS COULD STILL
DEVELOP FROM THE SOUTHERN BLACK HILLS TO SOUTH CENTRAL SD THROUGH
THE LATE AFTERNOON. A STRONG STORM IS STILL POSSIBLE IN THE
VICINITY OF THE SURFACE TROF OVER SOUTH CENTRAL SD.

HOT AND DRY WEATHER CAN BE EXPECTED THROUGH THE REST OF THE WEEKEND
AS RIDGE GRADUALLY SLIDES ACROSS THE ROCKIES. HIGHS WILL BE IN THE
90S ACROSS THE PLAINS...WITH 80S OVER THE BLACK HILLS. NORTHERLY
WINDS TONIGHT AND EARLY SUNDAY WILL GRADUALLY SHIFT OVER TO THE EAST
AND SOUTHEAST BY SUNDAY NIGHT AS HIGH PRESSURE SLIDES NORTH AND EAST
OF THE CWA.

.LONG TERM...MONDAY THROUGH SATURDAY
ISSUED AT 247 PM MDT SAT AUG 1 2015

MODELS IN DECENT AGREEMENT WITH THE OVERALL PATTERN THROUGH THE
WEEK. RIDGE BREAKS DOWN MONDAY/EARLY TUESDAY AS WEAK UPPER TROF
LIFTS THROUGH THE CENTRAL ROCKIES INTO THE PLAINS. EAST-SOUTHEAST
LOW LEVEL FLOW WILL BRING INCREASING BOUNDARY LAYER MOISTURE...
WHILE SURGE OF MID LEVEL MOISTURE ARRIVES WITH THE TROF. MAY BE A
FEW ISOLATED THUNDERSTORMS LATE MONDAY FROM THE BLACK HILLS INTO
SOUTH CENTRAL SOUTH DAKOTA. BETTER CHANCE OF THUNDERSTORMS ON
TUESDAY WITH WEAK UPPER TROF ACROSS THE NORTHERN PLAINS. WEAK
RIDGING ACROSS THE AREA FOR WEDNESDAY...THOUGH SUFFICIENT
INSTABILITY FOR A FEW THUNDERSTORMS. CHANCE OF STORMS WILL
CONTINUE THROUGH THE END OF THE WEEK AS UPPER TROF TRACKS ACROSS
THE PACIFIC NORTHWEST/NORTHERN ROCKIES.

&&

.AVIATION...FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING
ISSUED AT 534 PM MDT SAT AUG 1 2015

ISOLD TSRA MAY DVLP OVR BLK HLS INTO SOUTH CNTRL SD...
OTHERWISE...SKIES WL BE CLR. NW WNDS WL DCRS THIS EVEN...THEN
INCRS AGAIN SUN.

&&

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

$$

SHORT TERM...26
LONG TERM...10
AVIATION...55




000
FXUS63 KUNR 012337
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
537 PM MDT SAT AUG 1 2015

.SHORT TERM...THIS EVENING THROUGH SUNDAY NIGHT
ISSUED AT 247 PM MDT SAT AUG 1 2015

CURRENT SURFACE ANALYSIS SHOWS FRONTAL BOUNDARY/WARM FRONT NOW
STRETCHING FROM NORTHEAST MT TO EASTERN SD...WITH A SURFACE TROF
EXTENDING SOUTHWARD ACROSS CENTRAL SD. UPPER LEVEL ANALYSIS
CONTINUES TO SHOW RIDGE OVER THE WESTERN CONUS...WITH
NORTHWESTERLY FLOW OVER THE NORTHERN PLAINS. TEMPS ARE MOSTLY IN
THE 90S NOW ACROSS THE PLAINS...WITH 80S IN THE HILLS. WEAK
SHORTWAVE ENERGY WITH SHOWERS AND STORMS HAS MOVED SOUTH OF THE
CWA. HOWEVER...A COUPLE OF SHOWERS AND THUNDERSTORMS COULD STILL
DEVELOP FROM THE SOUTHERN BLACK HILLS TO SOUTH CENTRAL SD THROUGH
THE LATE AFTERNOON. A STRONG STORM IS STILL POSSIBLE IN THE
VICINITY OF THE SURFACE TROF OVER SOUTH CENTRAL SD.

HOT AND DRY WEATHER CAN BE EXPECTED THROUGH THE REST OF THE WEEKEND
AS RIDGE GRADUALLY SLIDES ACROSS THE ROCKIES. HIGHS WILL BE IN THE
90S ACROSS THE PLAINS...WITH 80S OVER THE BLACK HILLS. NORTHERLY
WINDS TONIGHT AND EARLY SUNDAY WILL GRADUALLY SHIFT OVER TO THE EAST
AND SOUTHEAST BY SUNDAY NIGHT AS HIGH PRESSURE SLIDES NORTH AND EAST
OF THE CWA.

.LONG TERM...MONDAY THROUGH SATURDAY
ISSUED AT 247 PM MDT SAT AUG 1 2015

MODELS IN DECENT AGREEMENT WITH THE OVERALL PATTERN THROUGH THE
WEEK. RIDGE BREAKS DOWN MONDAY/EARLY TUESDAY AS WEAK UPPER TROF
LIFTS THROUGH THE CENTRAL ROCKIES INTO THE PLAINS. EAST-SOUTHEAST
LOW LEVEL FLOW WILL BRING INCREASING BOUNDARY LAYER MOISTURE...
WHILE SURGE OF MID LEVEL MOISTURE ARRIVES WITH THE TROF. MAY BE A
FEW ISOLATED THUNDERSTORMS LATE MONDAY FROM THE BLACK HILLS INTO
SOUTH CENTRAL SOUTH DAKOTA. BETTER CHANCE OF THUNDERSTORMS ON
TUESDAY WITH WEAK UPPER TROF ACROSS THE NORTHERN PLAINS. WEAK
RIDGING ACROSS THE AREA FOR WEDNESDAY...THOUGH SUFFICIENT
INSTABILITY FOR A FEW THUNDERSTORMS. CHANCE OF STORMS WILL
CONTINUE THROUGH THE END OF THE WEEK AS UPPER TROF TRACKS ACROSS
THE PACIFIC NORTHWEST/NORTHERN ROCKIES.

&&

.AVIATION...FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING
ISSUED AT 534 PM MDT SAT AUG 1 2015

ISOLD TSRA MAY DVLP OVR BLK HLS INTO SOUTH CNTRL SD...
OTHERWISE...SKIES WL BE CLR. NW WNDS WL DCRS THIS EVEN...THEN
INCRS AGAIN SUN.

&&

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

$$

SHORT TERM...26
LONG TERM...10
AVIATION...55



000
FXUS63 KUNR 012337
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
537 PM MDT SAT AUG 1 2015

.SHORT TERM...THIS EVENING THROUGH SUNDAY NIGHT
ISSUED AT 247 PM MDT SAT AUG 1 2015

CURRENT SURFACE ANALYSIS SHOWS FRONTAL BOUNDARY/WARM FRONT NOW
STRETCHING FROM NORTHEAST MT TO EASTERN SD...WITH A SURFACE TROF
EXTENDING SOUTHWARD ACROSS CENTRAL SD. UPPER LEVEL ANALYSIS
CONTINUES TO SHOW RIDGE OVER THE WESTERN CONUS...WITH
NORTHWESTERLY FLOW OVER THE NORTHERN PLAINS. TEMPS ARE MOSTLY IN
THE 90S NOW ACROSS THE PLAINS...WITH 80S IN THE HILLS. WEAK
SHORTWAVE ENERGY WITH SHOWERS AND STORMS HAS MOVED SOUTH OF THE
CWA. HOWEVER...A COUPLE OF SHOWERS AND THUNDERSTORMS COULD STILL
DEVELOP FROM THE SOUTHERN BLACK HILLS TO SOUTH CENTRAL SD THROUGH
THE LATE AFTERNOON. A STRONG STORM IS STILL POSSIBLE IN THE
VICINITY OF THE SURFACE TROF OVER SOUTH CENTRAL SD.

HOT AND DRY WEATHER CAN BE EXPECTED THROUGH THE REST OF THE WEEKEND
AS RIDGE GRADUALLY SLIDES ACROSS THE ROCKIES. HIGHS WILL BE IN THE
90S ACROSS THE PLAINS...WITH 80S OVER THE BLACK HILLS. NORTHERLY
WINDS TONIGHT AND EARLY SUNDAY WILL GRADUALLY SHIFT OVER TO THE EAST
AND SOUTHEAST BY SUNDAY NIGHT AS HIGH PRESSURE SLIDES NORTH AND EAST
OF THE CWA.

.LONG TERM...MONDAY THROUGH SATURDAY
ISSUED AT 247 PM MDT SAT AUG 1 2015

MODELS IN DECENT AGREEMENT WITH THE OVERALL PATTERN THROUGH THE
WEEK. RIDGE BREAKS DOWN MONDAY/EARLY TUESDAY AS WEAK UPPER TROF
LIFTS THROUGH THE CENTRAL ROCKIES INTO THE PLAINS. EAST-SOUTHEAST
LOW LEVEL FLOW WILL BRING INCREASING BOUNDARY LAYER MOISTURE...
WHILE SURGE OF MID LEVEL MOISTURE ARRIVES WITH THE TROF. MAY BE A
FEW ISOLATED THUNDERSTORMS LATE MONDAY FROM THE BLACK HILLS INTO
SOUTH CENTRAL SOUTH DAKOTA. BETTER CHANCE OF THUNDERSTORMS ON
TUESDAY WITH WEAK UPPER TROF ACROSS THE NORTHERN PLAINS. WEAK
RIDGING ACROSS THE AREA FOR WEDNESDAY...THOUGH SUFFICIENT
INSTABILITY FOR A FEW THUNDERSTORMS. CHANCE OF STORMS WILL
CONTINUE THROUGH THE END OF THE WEEK AS UPPER TROF TRACKS ACROSS
THE PACIFIC NORTHWEST/NORTHERN ROCKIES.

&&

.AVIATION...FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING
ISSUED AT 534 PM MDT SAT AUG 1 2015

ISOLD TSRA MAY DVLP OVR BLK HLS INTO SOUTH CNTRL SD...
OTHERWISE...SKIES WL BE CLR. NW WNDS WL DCRS THIS EVEN...THEN
INCRS AGAIN SUN.

&&

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

$$

SHORT TERM...26
LONG TERM...10
AVIATION...55




000
FXUS63 KUNR 012337
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
537 PM MDT SAT AUG 1 2015

.SHORT TERM...THIS EVENING THROUGH SUNDAY NIGHT
ISSUED AT 247 PM MDT SAT AUG 1 2015

CURRENT SURFACE ANALYSIS SHOWS FRONTAL BOUNDARY/WARM FRONT NOW
STRETCHING FROM NORTHEAST MT TO EASTERN SD...WITH A SURFACE TROF
EXTENDING SOUTHWARD ACROSS CENTRAL SD. UPPER LEVEL ANALYSIS
CONTINUES TO SHOW RIDGE OVER THE WESTERN CONUS...WITH
NORTHWESTERLY FLOW OVER THE NORTHERN PLAINS. TEMPS ARE MOSTLY IN
THE 90S NOW ACROSS THE PLAINS...WITH 80S IN THE HILLS. WEAK
SHORTWAVE ENERGY WITH SHOWERS AND STORMS HAS MOVED SOUTH OF THE
CWA. HOWEVER...A COUPLE OF SHOWERS AND THUNDERSTORMS COULD STILL
DEVELOP FROM THE SOUTHERN BLACK HILLS TO SOUTH CENTRAL SD THROUGH
THE LATE AFTERNOON. A STRONG STORM IS STILL POSSIBLE IN THE
VICINITY OF THE SURFACE TROF OVER SOUTH CENTRAL SD.

HOT AND DRY WEATHER CAN BE EXPECTED THROUGH THE REST OF THE WEEKEND
AS RIDGE GRADUALLY SLIDES ACROSS THE ROCKIES. HIGHS WILL BE IN THE
90S ACROSS THE PLAINS...WITH 80S OVER THE BLACK HILLS. NORTHERLY
WINDS TONIGHT AND EARLY SUNDAY WILL GRADUALLY SHIFT OVER TO THE EAST
AND SOUTHEAST BY SUNDAY NIGHT AS HIGH PRESSURE SLIDES NORTH AND EAST
OF THE CWA.

.LONG TERM...MONDAY THROUGH SATURDAY
ISSUED AT 247 PM MDT SAT AUG 1 2015

MODELS IN DECENT AGREEMENT WITH THE OVERALL PATTERN THROUGH THE
WEEK. RIDGE BREAKS DOWN MONDAY/EARLY TUESDAY AS WEAK UPPER TROF
LIFTS THROUGH THE CENTRAL ROCKIES INTO THE PLAINS. EAST-SOUTHEAST
LOW LEVEL FLOW WILL BRING INCREASING BOUNDARY LAYER MOISTURE...
WHILE SURGE OF MID LEVEL MOISTURE ARRIVES WITH THE TROF. MAY BE A
FEW ISOLATED THUNDERSTORMS LATE MONDAY FROM THE BLACK HILLS INTO
SOUTH CENTRAL SOUTH DAKOTA. BETTER CHANCE OF THUNDERSTORMS ON
TUESDAY WITH WEAK UPPER TROF ACROSS THE NORTHERN PLAINS. WEAK
RIDGING ACROSS THE AREA FOR WEDNESDAY...THOUGH SUFFICIENT
INSTABILITY FOR A FEW THUNDERSTORMS. CHANCE OF STORMS WILL
CONTINUE THROUGH THE END OF THE WEEK AS UPPER TROF TRACKS ACROSS
THE PACIFIC NORTHWEST/NORTHERN ROCKIES.

&&

.AVIATION...FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING
ISSUED AT 534 PM MDT SAT AUG 1 2015

ISOLD TSRA MAY DVLP OVR BLK HLS INTO SOUTH CNTRL SD...
OTHERWISE...SKIES WL BE CLR. NW WNDS WL DCRS THIS EVEN...THEN
INCRS AGAIN SUN.

&&

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

$$

SHORT TERM...26
LONG TERM...10
AVIATION...55



000
FXUS65 KCYS 012144
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
344 PM MDT SAT AUG 1 2015

.SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT)
ISSUED AT 344 PM MDT SAT AUG 1 2015

CONVECTION HAS DEVELOPED THIS AFTERNOON OFF THE HIGHER TERRAIN...IN
ADDITION TO THE SURFACE TROUGH THAT IS SITUATED ROUGHLY NEAR
CHEYENNE TO CHADRON NEBRASKA. MODERATE INSTABILITY IS IN PLACE
EAST OF THIS AREA WITH DEW POINTS IN THE LOW 50S TO LOW 60S UNDER
FAIRLY STEEP LAPSE RATES. ONE STORM IN SOUTHERN SIOUX COUNTY
PULSED VIGOROUSLY AT TIMES EARLIER THIS AFTERNOON...AND WOULD
EXPECT THIS TO BE THE TREND THROUGH THE REST OF THE AFTERNOON WITH
CONVECTION EAST OF THIS BOUNDARY. DEEP LAYER SHEAR ANALYSIS SHOWS
ROUGHLY 30-40 KTS IN PLACE...SO SOME ORGANIZATION OF CONVECTION IS
POSSIBLE BUT THE MAJORITY OF STORMS WILL REMAIN PULSEY IN NATURE
WITH SOME HAIL...GUSTY WINDS AND MODERATE RAINFALL POSSIBLE OUT OF
THE STRONGER ACTIVITY. A WEAK WAVE APPROACHING FROM THE NORTHWEST
COULD KEEP A FEW STORMS GOING THROUGH SUNSET ALONG AND EAST OF THE
LARAMIE RANGE...ESPECIALLY IN AREAS OF OUTFLOW BOUNDARY
INTERACTION SO KEPT ISOLATED POPS FOR THESE AREAS THRU 03Z.
OTHERWISE TONIGHT SHOULD REMAIN DRY AND MILD.

THE SFC BOUNDARY WILL PUSH EAST TONIGHT AS THE WAVE MOVES
OVERHEAD...BUT YET ANOTHER SFC FRONT WILL DROP SOUTH ACROSS THE
PLAINS SUNDAY AFTERNOON. AT THE SAME TIME...A STRONGER SHORTWAVE
APPROACHING FROM THE SOUTHWEST WILL INDUCE STRONGER EAST-
SOUTHEASTERLY WINDS AT THE SFC AND LLVL MOISTURE ADVECTION THROUGH
THE DAY. THUS...WE ARE ONCE AGAIN EXPECTING ISOLATED SHOWERS AND
THUNDERSTORMS IN THE AFTERNOON FOR THE MOUNTAINS AND THE WYOMING
PLAINS AS THE FRONT PUSHES THROUGH AND WAVE APPROACHES FROM THE
SOUTHWEST. THAT SHORTWAVE WILL MOVE OVERHEAD ON MONDAY...BRINGING
WITH IT A MARKED INCREASE IN MONSOONAL MOISTURE. PERHAPS WILL SEE
SHOWERS/STORMS INITIATE EARLIER IN THE DAY AND WITH A BROADER
COVERAGE OF ACTIVITY ACROSS THE CWA. LOOKING AT MODERATE TO HEAVY
RAINFALL RATES FROM THIS ACTIVITY. WITH THE VERY DRY ANTECEDENTCONDITIONS
WEST OF THE LARAMIE RANGE AND ACROSS CONVERSE/NIOBRARA
COUNTIES...NOT ANTICIPATING ANY SIGNIFICANT FLOODING ISSUES HERE.
AREAS FURTHER SOUTH AND EAST...WILL HAVE TO WATCH FOR THE
POSSIBILITY OF FLASH FLOODING IN AREAS THAT SEE HEAVIER RAINFALL
OVER THE NEXT COUPLE OF DAYS WHICH COULD SATURATE SOILS.

.LONG TERM...(TUESDAY THROUGH SATURDAY)
ISSUED AT 344 PM MDT SAT AUG 1 2015

MODELS ARE IN A LITTLE BETTER AGREEMENT TODAY IN THE LONG
TERM...BUT STILL STRUGGLING WITH THE TIMING OF SHORT WAVE ENERGY
EMBEDDED IN THE WEST TO NORTHWEST FLOW ALOFT. ALL MODELS NOW
INDICATE A FLATTER RIDGE COMPARED TO THE LAST FEW DAYS...WITH
WEAK SHORTWAVE DISTURBANCES MOVING ACROSS THE AREA. TUESDAY
APPEARS TO BE FAVORABLE FOR SCATTERED COVERAGE OF SHOWERS AND
TSTORMS THROUGH THE AFTERNOON OVER THE HIGH PLAINS...SO KEPT POP
ON THE HIGH SIDE ALONG AND EAST OF I25. THE GFS AND ECMWF SHOW A
PAIR OF STRONGER DISTURBANCES ON WEDNESDAY AND THURSDAY...AS A
COOL FRONT ACCELERATES SOUTHWARD ACROSS THE HIGH PLAINS BRINGING
COOLER TEMPERATURES TO THE REGION. KEPT POP LOW DURING THE
WEDNESDAY- THURSDAY TIME PERIOD BECAUSE OF THE TIMING OF THE FRONT
AND ASSOCIATED DISTURBANCE ALOFT...WHICH ALL MODELS SHOW MOVING
EAST OF THE FORECAST AREA BY THE AFTERNOON. THIS WOULD PUT MOST OF
SOUTHEAST WYOMING UNDER THE MIDLEVEL SUBSIDENCE REGION BEHIND THE
TROUGH AXIS...WHICH IS NOT FAVORABLE FOR WIDESPREAD CONVECTION.
HOWEVER...THIS MAY CHANGE IN THE NEAR FUTURE IF MODEL SOLUTIONS
TREND A BIT MORE PROGRESSIVE. THE GFS AND ECMWF SOLUTIONS ARE
SIMILAR DURING THE MIDDLE OF THE WEEK...BUT THE ECMWF IS FAR MORE
WET...SHOWING LARGE AMOUNTS OF QPF EAST OF I25.

FOR LATE IN THE WEEK AND EARLY NEXT WEEKEND...MODELS ARE IN
REASONABLE AGREEMENT SHOWING AN UPPER LEVEL RIDGE AXIS MOVING
ACROSS THE FRONT RANGE...EXTENDING FROM COLORADO NORTHWARD INTO
SOUTHERN CANADA. ONCE THIS RIDGE AXIS PUSHES A BIT FURTHER
EAST...EXPECT A GREATER COVERAGE OF THUNDERSTORMS BY NEXT WEEKEND
AS SOME MONSOON MOISTURE BEGINS TO ADVECT NORTHWARD.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH SUNDAY MORNING)

ISOLATED TO WIDELY SCATTERED SHOWERS AND THUNDERSTORMS EXPECTED
ONCE AGAIN THIS AFTERNOON FOR AIRPORTS EAST OF THE LARAMIE RANGE.
GREATEST CONCENTRATION WILL BE IN THE NEBRASKA PANHANDLE. IT WILL
BE MAINLY DRY WEST OF THE LARAMIE RANGE TODAY WITH RELATIVELY
LIGHT WINDS AND VFR CONDITIONS.

&&

.FIRE WEATHER...
ISSUED AT 344 PM MDT SAT AUG 1 2015

HUMIDITIES HAVE DROPPED INTO THE LOW TO MID TEENS THIS AFTERNOON
WEST OF A LINE FROM CHEYENNE-CHADRON. A FEW GUSTS AROUND 20 MPH ARE
OCCURRING ACROSS THIS AREA AS WELL...WITH THE STRONGEST WINDS IN THE
NORTH SNOWY RANGE FOOTHILLS. ISOLATED SHOWERS AND THUNDERSTORMS
DEVELOPED OVER THE HIGH COUNTRY AND ALONG THIS BOUNDARY...WITH LIGHT
RAINFALL LIKELY IN THE MOUNTAINS AND MORE MODERATE RAINFALL RATES
ACROSS THE PLAINS.  MONSOONAL MOISTURE WILL MOVE IN FOR MONDAY AND
TUESDAY WITH HIGHER HUMIDITIES AND INCREASED CHANCES FOR AFTERNOON
AND EVENING THUNDERSTORMS. WARMER AND DRIER WEATHER WILL PREVAIL FOR
WEDNESDAY THROUGH FRIDAY.

&&

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

$$

SHORT TERM...RJM
LONG TERM...TJT
AVIATION...TJT
FIRE WEATHER...RJM




000
FXUS65 KCYS 012144
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
344 PM MDT SAT AUG 1 2015

.SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT)
ISSUED AT 344 PM MDT SAT AUG 1 2015

CONVECTION HAS DEVELOPED THIS AFTERNOON OFF THE HIGHER TERRAIN...IN
ADDITION TO THE SURFACE TROUGH THAT IS SITUATED ROUGHLY NEAR
CHEYENNE TO CHADRON NEBRASKA. MODERATE INSTABILITY IS IN PLACE
EAST OF THIS AREA WITH DEW POINTS IN THE LOW 50S TO LOW 60S UNDER
FAIRLY STEEP LAPSE RATES. ONE STORM IN SOUTHERN SIOUX COUNTY
PULSED VIGOROUSLY AT TIMES EARLIER THIS AFTERNOON...AND WOULD
EXPECT THIS TO BE THE TREND THROUGH THE REST OF THE AFTERNOON WITH
CONVECTION EAST OF THIS BOUNDARY. DEEP LAYER SHEAR ANALYSIS SHOWS
ROUGHLY 30-40 KTS IN PLACE...SO SOME ORGANIZATION OF CONVECTION IS
POSSIBLE BUT THE MAJORITY OF STORMS WILL REMAIN PULSEY IN NATURE
WITH SOME HAIL...GUSTY WINDS AND MODERATE RAINFALL POSSIBLE OUT OF
THE STRONGER ACTIVITY. A WEAK WAVE APPROACHING FROM THE NORTHWEST
COULD KEEP A FEW STORMS GOING THROUGH SUNSET ALONG AND EAST OF THE
LARAMIE RANGE...ESPECIALLY IN AREAS OF OUTFLOW BOUNDARY
INTERACTION SO KEPT ISOLATED POPS FOR THESE AREAS THRU 03Z.
OTHERWISE TONIGHT SHOULD REMAIN DRY AND MILD.

THE SFC BOUNDARY WILL PUSH EAST TONIGHT AS THE WAVE MOVES
OVERHEAD...BUT YET ANOTHER SFC FRONT WILL DROP SOUTH ACROSS THE
PLAINS SUNDAY AFTERNOON. AT THE SAME TIME...A STRONGER SHORTWAVE
APPROACHING FROM THE SOUTHWEST WILL INDUCE STRONGER EAST-
SOUTHEASTERLY WINDS AT THE SFC AND LLVL MOISTURE ADVECTION THROUGH
THE DAY. THUS...WE ARE ONCE AGAIN EXPECTING ISOLATED SHOWERS AND
THUNDERSTORMS IN THE AFTERNOON FOR THE MOUNTAINS AND THE WYOMING
PLAINS AS THE FRONT PUSHES THROUGH AND WAVE APPROACHES FROM THE
SOUTHWEST. THAT SHORTWAVE WILL MOVE OVERHEAD ON MONDAY...BRINGING
WITH IT A MARKED INCREASE IN MONSOONAL MOISTURE. PERHAPS WILL SEE
SHOWERS/STORMS INITIATE EARLIER IN THE DAY AND WITH A BROADER
COVERAGE OF ACTIVITY ACROSS THE CWA. LOOKING AT MODERATE TO HEAVY
RAINFALL RATES FROM THIS ACTIVITY. WITH THE VERY DRY ANTECEDENTCONDITIONS
WEST OF THE LARAMIE RANGE AND ACROSS CONVERSE/NIOBRARA
COUNTIES...NOT ANTICIPATING ANY SIGNIFICANT FLOODING ISSUES HERE.
AREAS FURTHER SOUTH AND EAST...WILL HAVE TO WATCH FOR THE
POSSIBILITY OF FLASH FLOODING IN AREAS THAT SEE HEAVIER RAINFALL
OVER THE NEXT COUPLE OF DAYS WHICH COULD SATURATE SOILS.

.LONG TERM...(TUESDAY THROUGH SATURDAY)
ISSUED AT 344 PM MDT SAT AUG 1 2015

MODELS ARE IN A LITTLE BETTER AGREEMENT TODAY IN THE LONG
TERM...BUT STILL STRUGGLING WITH THE TIMING OF SHORT WAVE ENERGY
EMBEDDED IN THE WEST TO NORTHWEST FLOW ALOFT. ALL MODELS NOW
INDICATE A FLATTER RIDGE COMPARED TO THE LAST FEW DAYS...WITH
WEAK SHORTWAVE DISTURBANCES MOVING ACROSS THE AREA. TUESDAY
APPEARS TO BE FAVORABLE FOR SCATTERED COVERAGE OF SHOWERS AND
TSTORMS THROUGH THE AFTERNOON OVER THE HIGH PLAINS...SO KEPT POP
ON THE HIGH SIDE ALONG AND EAST OF I25. THE GFS AND ECMWF SHOW A
PAIR OF STRONGER DISTURBANCES ON WEDNESDAY AND THURSDAY...AS A
COOL FRONT ACCELERATES SOUTHWARD ACROSS THE HIGH PLAINS BRINGING
COOLER TEMPERATURES TO THE REGION. KEPT POP LOW DURING THE
WEDNESDAY- THURSDAY TIME PERIOD BECAUSE OF THE TIMING OF THE FRONT
AND ASSOCIATED DISTURBANCE ALOFT...WHICH ALL MODELS SHOW MOVING
EAST OF THE FORECAST AREA BY THE AFTERNOON. THIS WOULD PUT MOST OF
SOUTHEAST WYOMING UNDER THE MIDLEVEL SUBSIDENCE REGION BEHIND THE
TROUGH AXIS...WHICH IS NOT FAVORABLE FOR WIDESPREAD CONVECTION.
HOWEVER...THIS MAY CHANGE IN THE NEAR FUTURE IF MODEL SOLUTIONS
TREND A BIT MORE PROGRESSIVE. THE GFS AND ECMWF SOLUTIONS ARE
SIMILAR DURING THE MIDDLE OF THE WEEK...BUT THE ECMWF IS FAR MORE
WET...SHOWING LARGE AMOUNTS OF QPF EAST OF I25.

FOR LATE IN THE WEEK AND EARLY NEXT WEEKEND...MODELS ARE IN
REASONABLE AGREEMENT SHOWING AN UPPER LEVEL RIDGE AXIS MOVING
ACROSS THE FRONT RANGE...EXTENDING FROM COLORADO NORTHWARD INTO
SOUTHERN CANADA. ONCE THIS RIDGE AXIS PUSHES A BIT FURTHER
EAST...EXPECT A GREATER COVERAGE OF THUNDERSTORMS BY NEXT WEEKEND
AS SOME MONSOON MOISTURE BEGINS TO ADVECT NORTHWARD.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH SUNDAY MORNING)

ISOLATED TO WIDELY SCATTERED SHOWERS AND THUNDERSTORMS EXPECTED
ONCE AGAIN THIS AFTERNOON FOR AIRPORTS EAST OF THE LARAMIE RANGE.
GREATEST CONCENTRATION WILL BE IN THE NEBRASKA PANHANDLE. IT WILL
BE MAINLY DRY WEST OF THE LARAMIE RANGE TODAY WITH RELATIVELY
LIGHT WINDS AND VFR CONDITIONS.

&&

.FIRE WEATHER...
ISSUED AT 344 PM MDT SAT AUG 1 2015

HUMIDITIES HAVE DROPPED INTO THE LOW TO MID TEENS THIS AFTERNOON
WEST OF A LINE FROM CHEYENNE-CHADRON. A FEW GUSTS AROUND 20 MPH ARE
OCCURRING ACROSS THIS AREA AS WELL...WITH THE STRONGEST WINDS IN THE
NORTH SNOWY RANGE FOOTHILLS. ISOLATED SHOWERS AND THUNDERSTORMS
DEVELOPED OVER THE HIGH COUNTRY AND ALONG THIS BOUNDARY...WITH LIGHT
RAINFALL LIKELY IN THE MOUNTAINS AND MORE MODERATE RAINFALL RATES
ACROSS THE PLAINS.  MONSOONAL MOISTURE WILL MOVE IN FOR MONDAY AND
TUESDAY WITH HIGHER HUMIDITIES AND INCREASED CHANCES FOR AFTERNOON
AND EVENING THUNDERSTORMS. WARMER AND DRIER WEATHER WILL PREVAIL FOR
WEDNESDAY THROUGH FRIDAY.

&&

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

$$

SHORT TERM...RJM
LONG TERM...TJT
AVIATION...TJT
FIRE WEATHER...RJM



000
FXUS63 KUNR 012047
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
247 PM MDT SAT AUG 1 2015

.SHORT TERM...THIS EVENING THROUGH SUNDAY NIGHT
ISSUED AT 247 PM MDT SAT AUG 1 2015

CURRENT SURFACE ANALYSIS SHOWS FRONTAL BOUNDARY/WARM FRONT NOW
STRETCHING FROM NORTHEAST MT TO EASTERN SD...WITH A SURFACE TROF
EXTENDING SOUTHWARD ACROSS CENTRAL SD. UPPER LEVEL ANALYSIS
CONTINUES TO SHOW RIDGE OVER THE WESTERN CONUS...WITH
NORTHWESTERLY FLOW OVER THE NORTHERN PLAINS. TEMPS ARE MOSTLY IN
THE 90S NOW ACROSS THE PLAINS...WITH 80S IN THE HILLS. WEAK
SHORTWAVE ENERGY WITH SHOWERS AND STORMS HAS MOVED SOUTH OF THE
CWA. HOWEVER...A COUPLE OF SHOWERS AND THUNDERSTORMS COULD STILL
DEVELOP FROM THE SOUTHERN BLACK HILLS TO SOUTH CENTRAL SD THROUGH
THE LATE AFTERNOON. A STRONG STORM IS STILL POSSIBLE IN THE
VICINITY OF THE SURFACE TROF OVER SOUTH CENTRAL SD.

HOT AND DRY WEATHER CAN BE EXPECTED THROUGH THE REST OF THE WEEKEND
AS RIDGE GRADUALLY SLIDES ACROSS THE ROCKIES. HIGHS WILL BE IN THE
90S ACROSS THE PLAINS...WITH 80S OVER THE BLACK HILLS. NORTHERLY
WINDS TONIGHT AND EARLY SUNDAY WILL GRADUALLY SHIFT OVER TO THE EAST
AND SOUTHEAST BY SUNDAY NIGHT AS HIGH PRESSURE SLIDES NORTH AND EAST
OF THE CWA.

.LONG TERM...MONDAY THROUGH SATURDAY
ISSUED AT 247 PM MDT SAT AUG 1 2015

MODELS IN DECENT AGREEMENT WITH THE OVERALL PATTERN THROUGH THE
WEEK. RIDGE BREAKS DOWN MONDAY/EARLY TUESDAY AS WEAK UPPER TROF
LIFTS THROUGH THE CENTRAL ROCKIES INTO THE PLAINS. EAST-SOUTHEAST
LOW LEVEL FLOW WILL BRING INCREASING BOUNDARY LAYER MOISTURE...
WHILE SURGE OF MID LEVEL MOISTURE ARRIVES WITH THE TROF. MAY BE A
FEW ISOLATED THUNDERSTORMS LATE MONDAY FROM THE BLACK HILLS INTO
SOUTH CENTRAL SOUTH DAKOTA. BETTER CHANCE OF THUNDERSTORMS ON
TUESDAY WITH WEAK UPPER TROF ACROSS THE NORTHERN PLAINS. WEAK
RIDGING ACROSS THE AREA FOR WEDNESDAY...THOUGH SUFFICIENT
INSTABILITY FOR A FEW THUNDERSTORMS. CHANCE OF STORMS WILL
CONTINUE THROUGH THE END OF THE WEEK AS UPPER TROF TRACKS ACROSS
THE PACIFIC NORTHWEST/NORTHERN ROCKIES.

&&

.AVIATION...FOR THE 18Z TAFS THROUGH 18Z SUNDAY
ISSUED AT 247 PM MDT SAT AUG 1 2015

ISOLATED SHRA/TSRA WILL BE FOUND ACROSS THE AREA TODAY...MAINLY
FROM THE BLACK HILLS INTO SOUTH CENTRAL SOUTH DAKOTA. LCL MVFR
CIGS/IFR VSBY WITH THE STRONGER STORMS. OTHERWISE...VFR CONDITIONS
EXPECTED THROUGH TONIGHT.

&&

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

$$

SHORT TERM...26
LONG TERM...10
AVIATION...10




000
FXUS63 KUNR 012047
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
247 PM MDT SAT AUG 1 2015

.SHORT TERM...THIS EVENING THROUGH SUNDAY NIGHT
ISSUED AT 247 PM MDT SAT AUG 1 2015

CURRENT SURFACE ANALYSIS SHOWS FRONTAL BOUNDARY/WARM FRONT NOW
STRETCHING FROM NORTHEAST MT TO EASTERN SD...WITH A SURFACE TROF
EXTENDING SOUTHWARD ACROSS CENTRAL SD. UPPER LEVEL ANALYSIS
CONTINUES TO SHOW RIDGE OVER THE WESTERN CONUS...WITH
NORTHWESTERLY FLOW OVER THE NORTHERN PLAINS. TEMPS ARE MOSTLY IN
THE 90S NOW ACROSS THE PLAINS...WITH 80S IN THE HILLS. WEAK
SHORTWAVE ENERGY WITH SHOWERS AND STORMS HAS MOVED SOUTH OF THE
CWA. HOWEVER...A COUPLE OF SHOWERS AND THUNDERSTORMS COULD STILL
DEVELOP FROM THE SOUTHERN BLACK HILLS TO SOUTH CENTRAL SD THROUGH
THE LATE AFTERNOON. A STRONG STORM IS STILL POSSIBLE IN THE
VICINITY OF THE SURFACE TROF OVER SOUTH CENTRAL SD.

HOT AND DRY WEATHER CAN BE EXPECTED THROUGH THE REST OF THE WEEKEND
AS RIDGE GRADUALLY SLIDES ACROSS THE ROCKIES. HIGHS WILL BE IN THE
90S ACROSS THE PLAINS...WITH 80S OVER THE BLACK HILLS. NORTHERLY
WINDS TONIGHT AND EARLY SUNDAY WILL GRADUALLY SHIFT OVER TO THE EAST
AND SOUTHEAST BY SUNDAY NIGHT AS HIGH PRESSURE SLIDES NORTH AND EAST
OF THE CWA.

.LONG TERM...MONDAY THROUGH SATURDAY
ISSUED AT 247 PM MDT SAT AUG 1 2015

MODELS IN DECENT AGREEMENT WITH THE OVERALL PATTERN THROUGH THE
WEEK. RIDGE BREAKS DOWN MONDAY/EARLY TUESDAY AS WEAK UPPER TROF
LIFTS THROUGH THE CENTRAL ROCKIES INTO THE PLAINS. EAST-SOUTHEAST
LOW LEVEL FLOW WILL BRING INCREASING BOUNDARY LAYER MOISTURE...
WHILE SURGE OF MID LEVEL MOISTURE ARRIVES WITH THE TROF. MAY BE A
FEW ISOLATED THUNDERSTORMS LATE MONDAY FROM THE BLACK HILLS INTO
SOUTH CENTRAL SOUTH DAKOTA. BETTER CHANCE OF THUNDERSTORMS ON
TUESDAY WITH WEAK UPPER TROF ACROSS THE NORTHERN PLAINS. WEAK
RIDGING ACROSS THE AREA FOR WEDNESDAY...THOUGH SUFFICIENT
INSTABILITY FOR A FEW THUNDERSTORMS. CHANCE OF STORMS WILL
CONTINUE THROUGH THE END OF THE WEEK AS UPPER TROF TRACKS ACROSS
THE PACIFIC NORTHWEST/NORTHERN ROCKIES.

&&

.AVIATION...FOR THE 18Z TAFS THROUGH 18Z SUNDAY
ISSUED AT 247 PM MDT SAT AUG 1 2015

ISOLATED SHRA/TSRA WILL BE FOUND ACROSS THE AREA TODAY...MAINLY
FROM THE BLACK HILLS INTO SOUTH CENTRAL SOUTH DAKOTA. LCL MVFR
CIGS/IFR VSBY WITH THE STRONGER STORMS. OTHERWISE...VFR CONDITIONS
EXPECTED THROUGH TONIGHT.

&&

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

$$

SHORT TERM...26
LONG TERM...10
AVIATION...10



000
FXUS63 KUNR 012047
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
247 PM MDT SAT AUG 1 2015

.SHORT TERM...THIS EVENING THROUGH SUNDAY NIGHT
ISSUED AT 247 PM MDT SAT AUG 1 2015

CURRENT SURFACE ANALYSIS SHOWS FRONTAL BOUNDARY/WARM FRONT NOW
STRETCHING FROM NORTHEAST MT TO EASTERN SD...WITH A SURFACE TROF
EXTENDING SOUTHWARD ACROSS CENTRAL SD. UPPER LEVEL ANALYSIS
CONTINUES TO SHOW RIDGE OVER THE WESTERN CONUS...WITH
NORTHWESTERLY FLOW OVER THE NORTHERN PLAINS. TEMPS ARE MOSTLY IN
THE 90S NOW ACROSS THE PLAINS...WITH 80S IN THE HILLS. WEAK
SHORTWAVE ENERGY WITH SHOWERS AND STORMS HAS MOVED SOUTH OF THE
CWA. HOWEVER...A COUPLE OF SHOWERS AND THUNDERSTORMS COULD STILL
DEVELOP FROM THE SOUTHERN BLACK HILLS TO SOUTH CENTRAL SD THROUGH
THE LATE AFTERNOON. A STRONG STORM IS STILL POSSIBLE IN THE
VICINITY OF THE SURFACE TROF OVER SOUTH CENTRAL SD.

HOT AND DRY WEATHER CAN BE EXPECTED THROUGH THE REST OF THE WEEKEND
AS RIDGE GRADUALLY SLIDES ACROSS THE ROCKIES. HIGHS WILL BE IN THE
90S ACROSS THE PLAINS...WITH 80S OVER THE BLACK HILLS. NORTHERLY
WINDS TONIGHT AND EARLY SUNDAY WILL GRADUALLY SHIFT OVER TO THE EAST
AND SOUTHEAST BY SUNDAY NIGHT AS HIGH PRESSURE SLIDES NORTH AND EAST
OF THE CWA.

.LONG TERM...MONDAY THROUGH SATURDAY
ISSUED AT 247 PM MDT SAT AUG 1 2015

MODELS IN DECENT AGREEMENT WITH THE OVERALL PATTERN THROUGH THE
WEEK. RIDGE BREAKS DOWN MONDAY/EARLY TUESDAY AS WEAK UPPER TROF
LIFTS THROUGH THE CENTRAL ROCKIES INTO THE PLAINS. EAST-SOUTHEAST
LOW LEVEL FLOW WILL BRING INCREASING BOUNDARY LAYER MOISTURE...
WHILE SURGE OF MID LEVEL MOISTURE ARRIVES WITH THE TROF. MAY BE A
FEW ISOLATED THUNDERSTORMS LATE MONDAY FROM THE BLACK HILLS INTO
SOUTH CENTRAL SOUTH DAKOTA. BETTER CHANCE OF THUNDERSTORMS ON
TUESDAY WITH WEAK UPPER TROF ACROSS THE NORTHERN PLAINS. WEAK
RIDGING ACROSS THE AREA FOR WEDNESDAY...THOUGH SUFFICIENT
INSTABILITY FOR A FEW THUNDERSTORMS. CHANCE OF STORMS WILL
CONTINUE THROUGH THE END OF THE WEEK AS UPPER TROF TRACKS ACROSS
THE PACIFIC NORTHWEST/NORTHERN ROCKIES.

&&

.AVIATION...FOR THE 18Z TAFS THROUGH 18Z SUNDAY
ISSUED AT 247 PM MDT SAT AUG 1 2015

ISOLATED SHRA/TSRA WILL BE FOUND ACROSS THE AREA TODAY...MAINLY
FROM THE BLACK HILLS INTO SOUTH CENTRAL SOUTH DAKOTA. LCL MVFR
CIGS/IFR VSBY WITH THE STRONGER STORMS. OTHERWISE...VFR CONDITIONS
EXPECTED THROUGH TONIGHT.

&&

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

$$

SHORT TERM...26
LONG TERM...10
AVIATION...10



000
FXUS65 KRIW 012031
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
231 PM MDT SAT AUG 1 2015

.SHORT TERM...TONIGHT THROUGH SUNDAY

WIDESPREAD HIGH PRESSURE EXPECTED TO CONTINUE ACROSS THE FORECAST
AREA. WARM TEMPERATURES WILL CONTINUE...ESPECIALLY ACROSS THE
NORTHERN BASINS WHERE VALUES WILL INCH CLOSER TOWARDS THE CENTURY
MARK.

CURRENT PATTERN REMAINS SUPPORTIVE OF LIGHT WIND THROUGH THE
FORECAST PERIOD AS WELL. A FEW HIGH CLOUDS COULD MOVE INTO THE
SOUTHERN PORTION OF THE FORECAST AREA SUNDAY AFTERNOON AS A WAVE
SLOWLY PROGRESSES TOWARDS THE STATE. MODELS CONTINUE TO SLOW THE
PROGRESS OF THIS WAVE. CURRENT PRECIPITATION FORECAST FOR SUNDAY
AFTERNOON MAY BE PESSIMISTIC BASED ON MOST RECENT MODEL
SOLUTIONS...BUT LEFT A FEW ISOLATED SHOWERS ACROSS THE
AREA...ESPECIALLY IN THE MID TO LATE AFTERNOON.

.LONG TERM...SUNDAY NIGHT THROUGH SATURDAY.

THE SHORTWAVE TROUGH FROM THE GREAT BASIN IS STILL EXPECTED TO MOVE
INTO WYOMING FROM SUNDAY NIGHT INTO MONDAY...ALTHOUGH ALL OF THE
MODELS SEEM TO HAVE SLOWED IT DOWN SOMEWHAT COMPARED TO YESTERDAYS
MODEL RUN.  THE RESULT WILL BE LESS OF A CHANCE OF PRECIPITATION
SUNDAY EVENING...WITH MORE OF A CONCENTRATION ON MONDAY...ESPECIALLY
DURING THE AFTERNOON AND EVENING HOURS.  SOUTHWEST WY WILL BE
IMPACTED FIRST...THEN THE REST OF CENTRAL AND SOUTHERN WY.  AT THIS
TIME EXPECTING GOOD MOISTURE AND MODERATE INSTABILITY TO BRING HEAVY
RAIN AND GUSTY OUTFLOW WIND WITH THE THUNDERSTORMS.  AS THE SYSTEM
PROGRESSES TO THE NORTHEAST...A BOUNDARY SHOULD DEVELOP ACROSS
CENTRAL WY WITH MOIST UNSTABLE AIR TO THE NORTH...AND DRIER WINDY
CONDITIONS TO THE SOUTH.  TUESDAY THEN WILL LIKELY SEE THE
CONVECTIVE ACTIVITY ACROSS NORTHERN WY.

ANOTHER WEAK SHORTWAVE TROUGH FROM THE PACIFIC THEN APPROACHES
WESTERN WY WED AFTERNOON AND EVENING...WITH THE GFS BEING THE
STRONGEST OF THE MEDIUM-RANGE MODELS.  HAVE GONE MORE OF A BLEND
WITH THE CHANCES OF PRECIPITATION...AND LIKE THE PREVIOUS
SHIFT...LEFT IN GUSTY WIND AS THE MAIN THREAT FROM THE
THUNDERSTORMS.  THE GENERAL PATTERN FROM MONDAY THROUGH WEDNESDAY
WILL KEEP TEMPERATURES NEAR OR BELOW NORMAL...WITH AN OBVIOUS
ENHANCEMENT FOR ABOVE NORMAL PRECIPITATION.

THURSDAY THROUGH SATURDAY LOOKS TO BE SLIGHTLY WARMER AND DRIER THAN
THE BEGINNING OF THE WEEK.  THURSDAY AFTERNOON AND EVENING SHOULD BE
FAIRLY DRY...EXCEPT FOR NE WY WITH SOME RESIDUAL INSTABILITY AND
MOISTURE FROM THE SHORTWAVE TROUGH.  BOTH THE GFS AND ECMWF INDICATE
ANOTHER SHORTWAVE TROUGH FROM THE PACIFIC MOVING INTO ID/MT/WY LATE
SATURDAY...AGAIN INCREASING THE CHANCE FOR SHOWERS AND
THUNDERSTORMS...BUT ALSO INCREASING THE WIND THROUGH CENTRAL AND
SOUTHERN WY.

&&

.AVIATION.../00Z ISSUANCE/

HIGH PRESSURE WILL KEEP VFR CONDITIONS AT AREA TERMINALS THROUGH
18Z SUNDAY. MOSTLY CLEAR SKIES WILL PERSIST THROUGH THE SAME
PERIOD...WITH LIGHT WIND. AS MENTIONED IN PREVIOUS
DISCUSSIONS...SOME DRAINAGE WINDS MAY BUMP UP WIND SPEEDS AT
FOOTHILL TERMINALS AFTER 00Z THIS EVENING...WITH WIDESPREAD LIGHT
WIND RETURNING BY 06Z THIS EVENING. AN APPROACHING SYSTEM MAY
INCREASE CLOUD COVER AFTER 18Z SUNDAY...ESPECIALLY ACROSS THE
SOUTHERN TERMINALS INCLUDING KRKS...KBPI...AND KPNA. CONDITIONS
ARE STILL GENERALLY EXPECTED TO REMAIN DRY...THOUGH A FEW SHOWERS
MAY BE LOCATED OVER THE MOUNTAIN AVIATION PASSES. THESE SHOWERS
COULD INCREASE TURBULENCE OVER THE MOUNTAIN PASSES.

&&

.FIRE WEATHER...

WARM AND DRY CONDITIONS WILL CONTINUE THROUGH SUNDAY MORNING...WITH
THE SLIGHT OPPORTUNITY FOR A FEW MOUNTAIN SHOWERS AND THUNDERSTORMS
SUNDAY AFTERNOON. AN APPROACHING WAVE FROM THE DESERT SOUTHWEST
CONTINUES TO LOOK LIKE THE NEXT WEATHER PRODUCING SYSTEM...THOUGH
MODELS CONTINUE TO DELAY ITS ARRIVAL INTO THE STATE. MONDAY
AFTERNOON NOW LOOKS FAIRLY FAVORABLE FOR SHOWERS AND THUNDERSTORMS
ASSOCIATED WITH THIS SYSTEM. MEANWHILE...THOUGH WARM AND DRY
CONDITIONS WILL PERSIST OTHERWISE WITH HUMIDITY IN THE LOW
TEENS...WINDS THROUGH MONDAY MORNING DO NOT LOOK SUPPORTIVE FOR
CRITICAL FIRE BEHAVIOR ACROSS THE AREA. WINDS DO GET STRONGER MONDAY
AFTERNOON...ESPECIALLY ACROSS SOUTHERN WYOMING. HOWEVER...MOST
LOCATIONS WHERE THE STRONGER WINDS ARE LOCATED WILL BE DEALING WITH
THE ARRIVAL OF THE AFOREMENTIONED WAVE OF LOW PRESSURE ELIMINATING
THE CONCERN FOR LOW HUMIDITY LEVELS.

&&

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

$$

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




000
FXUS65 KRIW 012031
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
231 PM MDT SAT AUG 1 2015

.SHORT TERM...TONIGHT THROUGH SUNDAY

WIDESPREAD HIGH PRESSURE EXPECTED TO CONTINUE ACROSS THE FORECAST
AREA. WARM TEMPERATURES WILL CONTINUE...ESPECIALLY ACROSS THE
NORTHERN BASINS WHERE VALUES WILL INCH CLOSER TOWARDS THE CENTURY
MARK.

CURRENT PATTERN REMAINS SUPPORTIVE OF LIGHT WIND THROUGH THE
FORECAST PERIOD AS WELL. A FEW HIGH CLOUDS COULD MOVE INTO THE
SOUTHERN PORTION OF THE FORECAST AREA SUNDAY AFTERNOON AS A WAVE
SLOWLY PROGRESSES TOWARDS THE STATE. MODELS CONTINUE TO SLOW THE
PROGRESS OF THIS WAVE. CURRENT PRECIPITATION FORECAST FOR SUNDAY
AFTERNOON MAY BE PESSIMISTIC BASED ON MOST RECENT MODEL
SOLUTIONS...BUT LEFT A FEW ISOLATED SHOWERS ACROSS THE
AREA...ESPECIALLY IN THE MID TO LATE AFTERNOON.

.LONG TERM...SUNDAY NIGHT THROUGH SATURDAY.

THE SHORTWAVE TROUGH FROM THE GREAT BASIN IS STILL EXPECTED TO MOVE
INTO WYOMING FROM SUNDAY NIGHT INTO MONDAY...ALTHOUGH ALL OF THE
MODELS SEEM TO HAVE SLOWED IT DOWN SOMEWHAT COMPARED TO YESTERDAYS
MODEL RUN.  THE RESULT WILL BE LESS OF A CHANCE OF PRECIPITATION
SUNDAY EVENING...WITH MORE OF A CONCENTRATION ON MONDAY...ESPECIALLY
DURING THE AFTERNOON AND EVENING HOURS.  SOUTHWEST WY WILL BE
IMPACTED FIRST...THEN THE REST OF CENTRAL AND SOUTHERN WY.  AT THIS
TIME EXPECTING GOOD MOISTURE AND MODERATE INSTABILITY TO BRING HEAVY
RAIN AND GUSTY OUTFLOW WIND WITH THE THUNDERSTORMS.  AS THE SYSTEM
PROGRESSES TO THE NORTHEAST...A BOUNDARY SHOULD DEVELOP ACROSS
CENTRAL WY WITH MOIST UNSTABLE AIR TO THE NORTH...AND DRIER WINDY
CONDITIONS TO THE SOUTH.  TUESDAY THEN WILL LIKELY SEE THE
CONVECTIVE ACTIVITY ACROSS NORTHERN WY.

ANOTHER WEAK SHORTWAVE TROUGH FROM THE PACIFIC THEN APPROACHES
WESTERN WY WED AFTERNOON AND EVENING...WITH THE GFS BEING THE
STRONGEST OF THE MEDIUM-RANGE MODELS.  HAVE GONE MORE OF A BLEND
WITH THE CHANCES OF PRECIPITATION...AND LIKE THE PREVIOUS
SHIFT...LEFT IN GUSTY WIND AS THE MAIN THREAT FROM THE
THUNDERSTORMS.  THE GENERAL PATTERN FROM MONDAY THROUGH WEDNESDAY
WILL KEEP TEMPERATURES NEAR OR BELOW NORMAL...WITH AN OBVIOUS
ENHANCEMENT FOR ABOVE NORMAL PRECIPITATION.

THURSDAY THROUGH SATURDAY LOOKS TO BE SLIGHTLY WARMER AND DRIER THAN
THE BEGINNING OF THE WEEK.  THURSDAY AFTERNOON AND EVENING SHOULD BE
FAIRLY DRY...EXCEPT FOR NE WY WITH SOME RESIDUAL INSTABILITY AND
MOISTURE FROM THE SHORTWAVE TROUGH.  BOTH THE GFS AND ECMWF INDICATE
ANOTHER SHORTWAVE TROUGH FROM THE PACIFIC MOVING INTO ID/MT/WY LATE
SATURDAY...AGAIN INCREASING THE CHANCE FOR SHOWERS AND
THUNDERSTORMS...BUT ALSO INCREASING THE WIND THROUGH CENTRAL AND
SOUTHERN WY.

&&

.AVIATION.../00Z ISSUANCE/

HIGH PRESSURE WILL KEEP VFR CONDITIONS AT AREA TERMINALS THROUGH
18Z SUNDAY. MOSTLY CLEAR SKIES WILL PERSIST THROUGH THE SAME
PERIOD...WITH LIGHT WIND. AS MENTIONED IN PREVIOUS
DISCUSSIONS...SOME DRAINAGE WINDS MAY BUMP UP WIND SPEEDS AT
FOOTHILL TERMINALS AFTER 00Z THIS EVENING...WITH WIDESPREAD LIGHT
WIND RETURNING BY 06Z THIS EVENING. AN APPROACHING SYSTEM MAY
INCREASE CLOUD COVER AFTER 18Z SUNDAY...ESPECIALLY ACROSS THE
SOUTHERN TERMINALS INCLUDING KRKS...KBPI...AND KPNA. CONDITIONS
ARE STILL GENERALLY EXPECTED TO REMAIN DRY...THOUGH A FEW SHOWERS
MAY BE LOCATED OVER THE MOUNTAIN AVIATION PASSES. THESE SHOWERS
COULD INCREASE TURBULENCE OVER THE MOUNTAIN PASSES.

&&

.FIRE WEATHER...

WARM AND DRY CONDITIONS WILL CONTINUE THROUGH SUNDAY MORNING...WITH
THE SLIGHT OPPORTUNITY FOR A FEW MOUNTAIN SHOWERS AND THUNDERSTORMS
SUNDAY AFTERNOON. AN APPROACHING WAVE FROM THE DESERT SOUTHWEST
CONTINUES TO LOOK LIKE THE NEXT WEATHER PRODUCING SYSTEM...THOUGH
MODELS CONTINUE TO DELAY ITS ARRIVAL INTO THE STATE. MONDAY
AFTERNOON NOW LOOKS FAIRLY FAVORABLE FOR SHOWERS AND THUNDERSTORMS
ASSOCIATED WITH THIS SYSTEM. MEANWHILE...THOUGH WARM AND DRY
CONDITIONS WILL PERSIST OTHERWISE WITH HUMIDITY IN THE LOW
TEENS...WINDS THROUGH MONDAY MORNING DO NOT LOOK SUPPORTIVE FOR
CRITICAL FIRE BEHAVIOR ACROSS THE AREA. WINDS DO GET STRONGER MONDAY
AFTERNOON...ESPECIALLY ACROSS SOUTHERN WYOMING. HOWEVER...MOST
LOCATIONS WHERE THE STRONGER WINDS ARE LOCATED WILL BE DEALING WITH
THE ARRIVAL OF THE AFOREMENTIONED WAVE OF LOW PRESSURE ELIMINATING
THE CONCERN FOR LOW HUMIDITY LEVELS.

&&

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

$$

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




000
FXUS65 KRIW 012031
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
231 PM MDT SAT AUG 1 2015

.SHORT TERM...TONIGHT THROUGH SUNDAY

WIDESPREAD HIGH PRESSURE EXPECTED TO CONTINUE ACROSS THE FORECAST
AREA. WARM TEMPERATURES WILL CONTINUE...ESPECIALLY ACROSS THE
NORTHERN BASINS WHERE VALUES WILL INCH CLOSER TOWARDS THE CENTURY
MARK.

CURRENT PATTERN REMAINS SUPPORTIVE OF LIGHT WIND THROUGH THE
FORECAST PERIOD AS WELL. A FEW HIGH CLOUDS COULD MOVE INTO THE
SOUTHERN PORTION OF THE FORECAST AREA SUNDAY AFTERNOON AS A WAVE
SLOWLY PROGRESSES TOWARDS THE STATE. MODELS CONTINUE TO SLOW THE
PROGRESS OF THIS WAVE. CURRENT PRECIPITATION FORECAST FOR SUNDAY
AFTERNOON MAY BE PESSIMISTIC BASED ON MOST RECENT MODEL
SOLUTIONS...BUT LEFT A FEW ISOLATED SHOWERS ACROSS THE
AREA...ESPECIALLY IN THE MID TO LATE AFTERNOON.

.LONG TERM...SUNDAY NIGHT THROUGH SATURDAY.

THE SHORTWAVE TROUGH FROM THE GREAT BASIN IS STILL EXPECTED TO MOVE
INTO WYOMING FROM SUNDAY NIGHT INTO MONDAY...ALTHOUGH ALL OF THE
MODELS SEEM TO HAVE SLOWED IT DOWN SOMEWHAT COMPARED TO YESTERDAYS
MODEL RUN.  THE RESULT WILL BE LESS OF A CHANCE OF PRECIPITATION
SUNDAY EVENING...WITH MORE OF A CONCENTRATION ON MONDAY...ESPECIALLY
DURING THE AFTERNOON AND EVENING HOURS.  SOUTHWEST WY WILL BE
IMPACTED FIRST...THEN THE REST OF CENTRAL AND SOUTHERN WY.  AT THIS
TIME EXPECTING GOOD MOISTURE AND MODERATE INSTABILITY TO BRING HEAVY
RAIN AND GUSTY OUTFLOW WIND WITH THE THUNDERSTORMS.  AS THE SYSTEM
PROGRESSES TO THE NORTHEAST...A BOUNDARY SHOULD DEVELOP ACROSS
CENTRAL WY WITH MOIST UNSTABLE AIR TO THE NORTH...AND DRIER WINDY
CONDITIONS TO THE SOUTH.  TUESDAY THEN WILL LIKELY SEE THE
CONVECTIVE ACTIVITY ACROSS NORTHERN WY.

ANOTHER WEAK SHORTWAVE TROUGH FROM THE PACIFIC THEN APPROACHES
WESTERN WY WED AFTERNOON AND EVENING...WITH THE GFS BEING THE
STRONGEST OF THE MEDIUM-RANGE MODELS.  HAVE GONE MORE OF A BLEND
WITH THE CHANCES OF PRECIPITATION...AND LIKE THE PREVIOUS
SHIFT...LEFT IN GUSTY WIND AS THE MAIN THREAT FROM THE
THUNDERSTORMS.  THE GENERAL PATTERN FROM MONDAY THROUGH WEDNESDAY
WILL KEEP TEMPERATURES NEAR OR BELOW NORMAL...WITH AN OBVIOUS
ENHANCEMENT FOR ABOVE NORMAL PRECIPITATION.

THURSDAY THROUGH SATURDAY LOOKS TO BE SLIGHTLY WARMER AND DRIER THAN
THE BEGINNING OF THE WEEK.  THURSDAY AFTERNOON AND EVENING SHOULD BE
FAIRLY DRY...EXCEPT FOR NE WY WITH SOME RESIDUAL INSTABILITY AND
MOISTURE FROM THE SHORTWAVE TROUGH.  BOTH THE GFS AND ECMWF INDICATE
ANOTHER SHORTWAVE TROUGH FROM THE PACIFIC MOVING INTO ID/MT/WY LATE
SATURDAY...AGAIN INCREASING THE CHANCE FOR SHOWERS AND
THUNDERSTORMS...BUT ALSO INCREASING THE WIND THROUGH CENTRAL AND
SOUTHERN WY.

&&

.AVIATION.../00Z ISSUANCE/

HIGH PRESSURE WILL KEEP VFR CONDITIONS AT AREA TERMINALS THROUGH
18Z SUNDAY. MOSTLY CLEAR SKIES WILL PERSIST THROUGH THE SAME
PERIOD...WITH LIGHT WIND. AS MENTIONED IN PREVIOUS
DISCUSSIONS...SOME DRAINAGE WINDS MAY BUMP UP WIND SPEEDS AT
FOOTHILL TERMINALS AFTER 00Z THIS EVENING...WITH WIDESPREAD LIGHT
WIND RETURNING BY 06Z THIS EVENING. AN APPROACHING SYSTEM MAY
INCREASE CLOUD COVER AFTER 18Z SUNDAY...ESPECIALLY ACROSS THE
SOUTHERN TERMINALS INCLUDING KRKS...KBPI...AND KPNA. CONDITIONS
ARE STILL GENERALLY EXPECTED TO REMAIN DRY...THOUGH A FEW SHOWERS
MAY BE LOCATED OVER THE MOUNTAIN AVIATION PASSES. THESE SHOWERS
COULD INCREASE TURBULENCE OVER THE MOUNTAIN PASSES.

&&

.FIRE WEATHER...

WARM AND DRY CONDITIONS WILL CONTINUE THROUGH SUNDAY MORNING...WITH
THE SLIGHT OPPORTUNITY FOR A FEW MOUNTAIN SHOWERS AND THUNDERSTORMS
SUNDAY AFTERNOON. AN APPROACHING WAVE FROM THE DESERT SOUTHWEST
CONTINUES TO LOOK LIKE THE NEXT WEATHER PRODUCING SYSTEM...THOUGH
MODELS CONTINUE TO DELAY ITS ARRIVAL INTO THE STATE. MONDAY
AFTERNOON NOW LOOKS FAIRLY FAVORABLE FOR SHOWERS AND THUNDERSTORMS
ASSOCIATED WITH THIS SYSTEM. MEANWHILE...THOUGH WARM AND DRY
CONDITIONS WILL PERSIST OTHERWISE WITH HUMIDITY IN THE LOW
TEENS...WINDS THROUGH MONDAY MORNING DO NOT LOOK SUPPORTIVE FOR
CRITICAL FIRE BEHAVIOR ACROSS THE AREA. WINDS DO GET STRONGER MONDAY
AFTERNOON...ESPECIALLY ACROSS SOUTHERN WYOMING. HOWEVER...MOST
LOCATIONS WHERE THE STRONGER WINDS ARE LOCATED WILL BE DEALING WITH
THE ARRIVAL OF THE AFOREMENTIONED WAVE OF LOW PRESSURE ELIMINATING
THE CONCERN FOR LOW HUMIDITY LEVELS.

&&

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

$$

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




000
FXUS65 KRIW 012031
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
231 PM MDT SAT AUG 1 2015

.SHORT TERM...TONIGHT THROUGH SUNDAY

WIDESPREAD HIGH PRESSURE EXPECTED TO CONTINUE ACROSS THE FORECAST
AREA. WARM TEMPERATURES WILL CONTINUE...ESPECIALLY ACROSS THE
NORTHERN BASINS WHERE VALUES WILL INCH CLOSER TOWARDS THE CENTURY
MARK.

CURRENT PATTERN REMAINS SUPPORTIVE OF LIGHT WIND THROUGH THE
FORECAST PERIOD AS WELL. A FEW HIGH CLOUDS COULD MOVE INTO THE
SOUTHERN PORTION OF THE FORECAST AREA SUNDAY AFTERNOON AS A WAVE
SLOWLY PROGRESSES TOWARDS THE STATE. MODELS CONTINUE TO SLOW THE
PROGRESS OF THIS WAVE. CURRENT PRECIPITATION FORECAST FOR SUNDAY
AFTERNOON MAY BE PESSIMISTIC BASED ON MOST RECENT MODEL
SOLUTIONS...BUT LEFT A FEW ISOLATED SHOWERS ACROSS THE
AREA...ESPECIALLY IN THE MID TO LATE AFTERNOON.

.LONG TERM...SUNDAY NIGHT THROUGH SATURDAY.

THE SHORTWAVE TROUGH FROM THE GREAT BASIN IS STILL EXPECTED TO MOVE
INTO WYOMING FROM SUNDAY NIGHT INTO MONDAY...ALTHOUGH ALL OF THE
MODELS SEEM TO HAVE SLOWED IT DOWN SOMEWHAT COMPARED TO YESTERDAYS
MODEL RUN.  THE RESULT WILL BE LESS OF A CHANCE OF PRECIPITATION
SUNDAY EVENING...WITH MORE OF A CONCENTRATION ON MONDAY...ESPECIALLY
DURING THE AFTERNOON AND EVENING HOURS.  SOUTHWEST WY WILL BE
IMPACTED FIRST...THEN THE REST OF CENTRAL AND SOUTHERN WY.  AT THIS
TIME EXPECTING GOOD MOISTURE AND MODERATE INSTABILITY TO BRING HEAVY
RAIN AND GUSTY OUTFLOW WIND WITH THE THUNDERSTORMS.  AS THE SYSTEM
PROGRESSES TO THE NORTHEAST...A BOUNDARY SHOULD DEVELOP ACROSS
CENTRAL WY WITH MOIST UNSTABLE AIR TO THE NORTH...AND DRIER WINDY
CONDITIONS TO THE SOUTH.  TUESDAY THEN WILL LIKELY SEE THE
CONVECTIVE ACTIVITY ACROSS NORTHERN WY.

ANOTHER WEAK SHORTWAVE TROUGH FROM THE PACIFIC THEN APPROACHES
WESTERN WY WED AFTERNOON AND EVENING...WITH THE GFS BEING THE
STRONGEST OF THE MEDIUM-RANGE MODELS.  HAVE GONE MORE OF A BLEND
WITH THE CHANCES OF PRECIPITATION...AND LIKE THE PREVIOUS
SHIFT...LEFT IN GUSTY WIND AS THE MAIN THREAT FROM THE
THUNDERSTORMS.  THE GENERAL PATTERN FROM MONDAY THROUGH WEDNESDAY
WILL KEEP TEMPERATURES NEAR OR BELOW NORMAL...WITH AN OBVIOUS
ENHANCEMENT FOR ABOVE NORMAL PRECIPITATION.

THURSDAY THROUGH SATURDAY LOOKS TO BE SLIGHTLY WARMER AND DRIER THAN
THE BEGINNING OF THE WEEK.  THURSDAY AFTERNOON AND EVENING SHOULD BE
FAIRLY DRY...EXCEPT FOR NE WY WITH SOME RESIDUAL INSTABILITY AND
MOISTURE FROM THE SHORTWAVE TROUGH.  BOTH THE GFS AND ECMWF INDICATE
ANOTHER SHORTWAVE TROUGH FROM THE PACIFIC MOVING INTO ID/MT/WY LATE
SATURDAY...AGAIN INCREASING THE CHANCE FOR SHOWERS AND
THUNDERSTORMS...BUT ALSO INCREASING THE WIND THROUGH CENTRAL AND
SOUTHERN WY.

&&

.AVIATION.../00Z ISSUANCE/

HIGH PRESSURE WILL KEEP VFR CONDITIONS AT AREA TERMINALS THROUGH
18Z SUNDAY. MOSTLY CLEAR SKIES WILL PERSIST THROUGH THE SAME
PERIOD...WITH LIGHT WIND. AS MENTIONED IN PREVIOUS
DISCUSSIONS...SOME DRAINAGE WINDS MAY BUMP UP WIND SPEEDS AT
FOOTHILL TERMINALS AFTER 00Z THIS EVENING...WITH WIDESPREAD LIGHT
WIND RETURNING BY 06Z THIS EVENING. AN APPROACHING SYSTEM MAY
INCREASE CLOUD COVER AFTER 18Z SUNDAY...ESPECIALLY ACROSS THE
SOUTHERN TERMINALS INCLUDING KRKS...KBPI...AND KPNA. CONDITIONS
ARE STILL GENERALLY EXPECTED TO REMAIN DRY...THOUGH A FEW SHOWERS
MAY BE LOCATED OVER THE MOUNTAIN AVIATION PASSES. THESE SHOWERS
COULD INCREASE TURBULENCE OVER THE MOUNTAIN PASSES.

&&

.FIRE WEATHER...

WARM AND DRY CONDITIONS WILL CONTINUE THROUGH SUNDAY MORNING...WITH
THE SLIGHT OPPORTUNITY FOR A FEW MOUNTAIN SHOWERS AND THUNDERSTORMS
SUNDAY AFTERNOON. AN APPROACHING WAVE FROM THE DESERT SOUTHWEST
CONTINUES TO LOOK LIKE THE NEXT WEATHER PRODUCING SYSTEM...THOUGH
MODELS CONTINUE TO DELAY ITS ARRIVAL INTO THE STATE. MONDAY
AFTERNOON NOW LOOKS FAIRLY FAVORABLE FOR SHOWERS AND THUNDERSTORMS
ASSOCIATED WITH THIS SYSTEM. MEANWHILE...THOUGH WARM AND DRY
CONDITIONS WILL PERSIST OTHERWISE WITH HUMIDITY IN THE LOW
TEENS...WINDS THROUGH MONDAY MORNING DO NOT LOOK SUPPORTIVE FOR
CRITICAL FIRE BEHAVIOR ACROSS THE AREA. WINDS DO GET STRONGER MONDAY
AFTERNOON...ESPECIALLY ACROSS SOUTHERN WYOMING. HOWEVER...MOST
LOCATIONS WHERE THE STRONGER WINDS ARE LOCATED WILL BE DEALING WITH
THE ARRIVAL OF THE AFOREMENTIONED WAVE OF LOW PRESSURE ELIMINATING
THE CONCERN FOR LOW HUMIDITY LEVELS.

&&

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

$$

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




000
FXUS65 KCYS 011731
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
1132 AM MDT SAT AUG 1 2015

.SHORT TERM...(TODAY THROUGH MONDAY NIGHT)

ISSUED AT 152 AM MDT SAT AUG 1 2015

TODAY...FLOW ALOFT REMAINS NORTHWEST. IN THE AFTERNOON...NAM PROGS A
LOW LEVEL CONVERGENCE AXIS TO SETUP FROM NEAR CHEYENNE TO NEAR
CHADRON WITH A LOW AND MID LEVEL THETA-E RIDGE AXIS ALSO SETTING UP
SOUTH OF THE CHEYENNE TO CHADRON LINE. LOOKS LIKE ENOUGH LOW LEVEL
CONVERGENCE DESPITE THE WARM TEMPERATURES ALOFT TO SPARK ISOLATED
AFTERNOON THUNDERSTORMS ALONG THE CONVERGENCE AXIS AND WILL CONTINUE
TO PAINT 10 TO 25 PERCENT POPS...DRY ELSEWHERE.

TONIGHT...ISOLATED THUNDERSTORMS SHOULD QUICKLY END IN THE EVENING
WITH LOSS OF DAYTIME HEATING...WITH DECREASING CLOUD COVER.

SUNDAY/SUNDAY NIGHT...AGAIN...WARM TEMPERATURES AT MID LEVELS WILL
LIMIT CONVECTIVE POTENTIAL AND CONVECTIVE DEVELOPMENT.
HOWEVER...WITH A LOW LEVEL INSTABILITY AXIS FROM NEAR GRAND JUNCTION
COLORADO TO DOUGLAS WYOMING...BELIEVE THAT ISOLATED THUNDERSTORMS
WILL BE SPARKED IN THE AFTERNOON OVER MUCH OF ALBANY COUNTY NEAR
LARAMIE AND OVER SOUTHERN LARAMIE COUNTY NEAR CHEYENNE. STORMS
EXPECTED TO END SUNDAY EVENING WITH LOSS OF DAYTIME HEATING.

MONDAY/MONDAY NIGHT...MODELS FORECAST THE LOW AND MID LEVEL
MONSOONAL MOISTURE TO SLIDE ACROSS OUR COUNTIES AND COMBINED WITH A
NEGATIVELY TILTED SHORTWAVE TROUGH ALOFT...WE EXPECT SCATTERED TO
NUMEROUS SHOWERS AND SCATTERED THUNDERSTORMS TO ERUPT IN THE
AFTERNOON AND EVENING...MAINLY ALONG AND WEST OF INTERSTATE 25 NEAR
THE LOW AND MID LEVEL THETA-E RIDGE AXIS.

.LONG TERM...(TUESDAY THROUGH FRIDAY)
ISSUED AT 300 AM MDT SAT AUG 1 2015

STILL A LOT OF FLIP FLOPPING WITH MEDIUM RANGE GUIDANCE ON WHAT IS
GOING TO HAPPEN IN THE LONG TERM. NOW THE GFS IS THE MORE BULLISH ON
POPS AND QPF FOR TUESDAY. ECMWF WAS THE MORE BULLISH 24 HOURS AGO.
LEADS TO LESS CONFIDENCE WITH THESE RUN TO RUN INCONSISTENCIES.

BOTH BRING A SHORTWAVE THROUGH THE CWFA MONDAY NIGHT INTO TUESDAY.
GFS BRINGS THE SHORTWAVE FURTHER NORTH WHILE THE ECMWF HAS THE
SHORTWAVE TRACKING ALONG THE COLORADO/WYOMING BORDER. DECIDED TO
MAINTAIN LOW CHANCE TO SLIGHT CHANCE POPS IN THE FORECAST FOR
TUESDAY WITH THE HOPES THAT RUN TO RUN CONSISTENCY INCREASES IN
ORDER TO RAISE POPS AS THE EVENT DRAWS CLOSER. SHOULD THE GFS
SOLUTION CURRENTLY BEING PROPOSED HOLDS TRUE...PANHANDLE AND
EXTREME SOUTHEAST WYOMING ZONES WOULD BE IN FOR HEAVY RAINFALL.
GFS FORECAST OVER 2 INCHES OF RAIN IN THE PANHANDLE FOR TUESDAY AS
THE FRONT STALLS ALONG THE LARAMIE RANGE.

BOTH MODELS SHOWING A FAIRLY DRY DAY WEDNESDAY AS SHORTWAVE MOVES
EAST AND IS REPLACED WITH UPPER LEVEL RIDGING. SURFACE BOUNDARY
GETS FORCED OUT INTO THE PANHANDLE WEDNESDAY AFTERNOON. MOST OF
SOUTHEAST WYOMING WOULD BE DRY AS WESTERLY WINDS CREATE DRY
DOWNSLOPING CONDITIONS OFF THE LARAMIE RANGE. COULD BE QUITE
BREEZY OUT WEST WEDNESDAY AS GFS 700MB WINDS INCREASE TO 30-35KTS.
IN FACT...THE GFS SHOWS THESE STRONG WESTERLY WINDS CONTINUING FOR
THE REST OF THE WEEK. WE WOULD BE DEALING WITH ELEVATED TO
CRITICAL FIRE WEATHER ISSUES UNDER THIS SCENARIO FOR MUCH OF NEXT
WEEK AS AFTERNOON HUMIDITIES LIKELY TO BECOME CRITICAL.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH SUNDAY MORNING)

ISOLATED TO WIDELY SCATTERED SHOWERS AND THUNDERSTORMS EXPECTED
ONCE AGAIN THIS AFTERNOON FOR AIRPORTS EAST OF THE LARAMIE RANGE.
GREATEST CONCENTRATION WILL BE IN THE NEBRASKA PANHANDLE. IT WILL BE
MAINLY DRY WEST OF THE LARAMIE RANGE TODAY WITH RELATIVELY LIGHT
WINDS AND VFR CONDITITIONS.

&&

.FIRE WEATHER...
ISSUED AT 152 AM MDT SAT AUG 1 2015

LOW AFTERNOON RELATIVE HUMIDITIES WEST OF INTERSTATE
25 TODAY AND SUNDAY...THOUGH FORTUNATELY...WINDS AND WIND GUSTS WILL
REMAIN BELOW CRITERIA FOR A MAJORITY OF LOCATIONS. RAIN CHANCES
INCREASE MONDAY AND TUESDAY AS MONSOONAL MOISTURE CREEPS BACK INTO
OUR COUNTIES.

&&

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

$$

SHORT TERM...RUBIN
LONG TERM...GCC
AVIATION...TJT
FIRE WEATHER...RUBIN



000
FXUS65 KCYS 011731
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
1132 AM MDT SAT AUG 1 2015

.SHORT TERM...(TODAY THROUGH MONDAY NIGHT)

ISSUED AT 152 AM MDT SAT AUG 1 2015

TODAY...FLOW ALOFT REMAINS NORTHWEST. IN THE AFTERNOON...NAM PROGS A
LOW LEVEL CONVERGENCE AXIS TO SETUP FROM NEAR CHEYENNE TO NEAR
CHADRON WITH A LOW AND MID LEVEL THETA-E RIDGE AXIS ALSO SETTING UP
SOUTH OF THE CHEYENNE TO CHADRON LINE. LOOKS LIKE ENOUGH LOW LEVEL
CONVERGENCE DESPITE THE WARM TEMPERATURES ALOFT TO SPARK ISOLATED
AFTERNOON THUNDERSTORMS ALONG THE CONVERGENCE AXIS AND WILL CONTINUE
TO PAINT 10 TO 25 PERCENT POPS...DRY ELSEWHERE.

TONIGHT...ISOLATED THUNDERSTORMS SHOULD QUICKLY END IN THE EVENING
WITH LOSS OF DAYTIME HEATING...WITH DECREASING CLOUD COVER.

SUNDAY/SUNDAY NIGHT...AGAIN...WARM TEMPERATURES AT MID LEVELS WILL
LIMIT CONVECTIVE POTENTIAL AND CONVECTIVE DEVELOPMENT.
HOWEVER...WITH A LOW LEVEL INSTABILITY AXIS FROM NEAR GRAND JUNCTION
COLORADO TO DOUGLAS WYOMING...BELIEVE THAT ISOLATED THUNDERSTORMS
WILL BE SPARKED IN THE AFTERNOON OVER MUCH OF ALBANY COUNTY NEAR
LARAMIE AND OVER SOUTHERN LARAMIE COUNTY NEAR CHEYENNE. STORMS
EXPECTED TO END SUNDAY EVENING WITH LOSS OF DAYTIME HEATING.

MONDAY/MONDAY NIGHT...MODELS FORECAST THE LOW AND MID LEVEL
MONSOONAL MOISTURE TO SLIDE ACROSS OUR COUNTIES AND COMBINED WITH A
NEGATIVELY TILTED SHORTWAVE TROUGH ALOFT...WE EXPECT SCATTERED TO
NUMEROUS SHOWERS AND SCATTERED THUNDERSTORMS TO ERUPT IN THE
AFTERNOON AND EVENING...MAINLY ALONG AND WEST OF INTERSTATE 25 NEAR
THE LOW AND MID LEVEL THETA-E RIDGE AXIS.

.LONG TERM...(TUESDAY THROUGH FRIDAY)
ISSUED AT 300 AM MDT SAT AUG 1 2015

STILL A LOT OF FLIP FLOPPING WITH MEDIUM RANGE GUIDANCE ON WHAT IS
GOING TO HAPPEN IN THE LONG TERM. NOW THE GFS IS THE MORE BULLISH ON
POPS AND QPF FOR TUESDAY. ECMWF WAS THE MORE BULLISH 24 HOURS AGO.
LEADS TO LESS CONFIDENCE WITH THESE RUN TO RUN INCONSISTENCIES.

BOTH BRING A SHORTWAVE THROUGH THE CWFA MONDAY NIGHT INTO TUESDAY.
GFS BRINGS THE SHORTWAVE FURTHER NORTH WHILE THE ECMWF HAS THE
SHORTWAVE TRACKING ALONG THE COLORADO/WYOMING BORDER. DECIDED TO
MAINTAIN LOW CHANCE TO SLIGHT CHANCE POPS IN THE FORECAST FOR
TUESDAY WITH THE HOPES THAT RUN TO RUN CONSISTENCY INCREASES IN
ORDER TO RAISE POPS AS THE EVENT DRAWS CLOSER. SHOULD THE GFS
SOLUTION CURRENTLY BEING PROPOSED HOLDS TRUE...PANHANDLE AND
EXTREME SOUTHEAST WYOMING ZONES WOULD BE IN FOR HEAVY RAINFALL.
GFS FORECAST OVER 2 INCHES OF RAIN IN THE PANHANDLE FOR TUESDAY AS
THE FRONT STALLS ALONG THE LARAMIE RANGE.

BOTH MODELS SHOWING A FAIRLY DRY DAY WEDNESDAY AS SHORTWAVE MOVES
EAST AND IS REPLACED WITH UPPER LEVEL RIDGING. SURFACE BOUNDARY
GETS FORCED OUT INTO THE PANHANDLE WEDNESDAY AFTERNOON. MOST OF
SOUTHEAST WYOMING WOULD BE DRY AS WESTERLY WINDS CREATE DRY
DOWNSLOPING CONDITIONS OFF THE LARAMIE RANGE. COULD BE QUITE
BREEZY OUT WEST WEDNESDAY AS GFS 700MB WINDS INCREASE TO 30-35KTS.
IN FACT...THE GFS SHOWS THESE STRONG WESTERLY WINDS CONTINUING FOR
THE REST OF THE WEEK. WE WOULD BE DEALING WITH ELEVATED TO
CRITICAL FIRE WEATHER ISSUES UNDER THIS SCENARIO FOR MUCH OF NEXT
WEEK AS AFTERNOON HUMIDITIES LIKELY TO BECOME CRITICAL.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH SUNDAY MORNING)

ISOLATED TO WIDELY SCATTERED SHOWERS AND THUNDERSTORMS EXPECTED
ONCE AGAIN THIS AFTERNOON FOR AIRPORTS EAST OF THE LARAMIE RANGE.
GREATEST CONCENTRATION WILL BE IN THE NEBRASKA PANHANDLE. IT WILL BE
MAINLY DRY WEST OF THE LARAMIE RANGE TODAY WITH RELATIVELY LIGHT
WINDS AND VFR CONDITITIONS.

&&

.FIRE WEATHER...
ISSUED AT 152 AM MDT SAT AUG 1 2015

LOW AFTERNOON RELATIVE HUMIDITIES WEST OF INTERSTATE
25 TODAY AND SUNDAY...THOUGH FORTUNATELY...WINDS AND WIND GUSTS WILL
REMAIN BELOW CRITERIA FOR A MAJORITY OF LOCATIONS. RAIN CHANCES
INCREASE MONDAY AND TUESDAY AS MONSOONAL MOISTURE CREEPS BACK INTO
OUR COUNTIES.

&&

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

$$

SHORT TERM...RUBIN
LONG TERM...GCC
AVIATION...TJT
FIRE WEATHER...RUBIN




000
FXUS65 KRIW 011720
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
1120 AM MDT SAT AUG 1 2015

.SHORT TERM...TODAY THROUGH MONDAY NIGHT

WV IMAGERY SHOWING RIDGE WRN CONUS...TROF ERN CONUS. UPR LVL CENTER
OF THIS HIGH LOCATED OVR NM WITH A STRONGER EMBEDDED WAVE OVR SFC
LOW...VERY TROPICAL LOOKING...NOW ACROSS AZ. A WEAK EMBEDDED SW IS
NOW MOVING DOWN THE EAST SIDE OF THE RIDGE ACROSS NRN/NERN WY WITH
ONLY A FEW SPURIOUS HIGH BASED SHOWERS ACROSS THE NORTH ATTM...WITH
LITTLE PRECIP...IF ANY...ACTUALLY REACHING THE GROUND. SFC HAS
GENERAL WEAK SFC GRAD ACROSS THE FA...WITH AN ALSO WEAK TROF
STRETCHING N/S FROM NCNTRL WY TO CNTRL WY.

HOT AND DRY TODAY SANS PRECIP AT ANY LOCATION IN THE CWA AS DRY AIR
ADVECTS FROM THE WEST OVR THE FA AND ANY SIGNIFICANT MOISTURE IS
HELD AT BAY WELL TO THE SOUTH. SUNDAY...HOTTEST DAY OF THE
PERIOD...WITH WEAK MOISTURE STARTING TO SLOWLY WORK ITS WAY INTO THE
FA THRU THE DAY...ALLOWING FOR LOW CHANCE PRECIP ACROSS FAVORED HIGH
MOUNTAIN RANGES LATER SUNDAY AFTERNOON/EVENING. HOWEVER...IT DOES
LOOK LIKE MOST OF THE PRECIP WILL STILL BE HELD OFF TO THE SOUTH AS
ON SATURDAY. THIS WILL BE A PRECURSOR TO MUCH BETTER CHCS FOR PRECIP
ON MONDAY...AS THE UPR RIDGE AXIS ROTATES CLOCKWISE AND CENTERS OVR
WY WHILE BETTER MONSOONAL MOISTURE STARTS TO FEED ACROSS WY ALONG
WITH WHAT WAS THE AZ DISTURBANCE...MENTIONED ABOVE...MOVING
OVERHEAD. PWS SHOULD BE HIGHER THAN NORMAL...APPROACHING AN INCH IN
SOME PLACES...AND STORM MOTION WILL BE VERY SLOW WITH JET PUSHED OFF
TO THE N AND E...BOTH CONDITIONS TOGETHER GIVING THE POSSIBILITY
FOR AT LEAST ISOLATED FLASH FLOODING.

.LONG TERM...TUESDAY THROUGH SATURDAY

LONG RANGE MODELS MOVE THIS WEATHER SYSTEM ACROSS THE REGION
TUESDAY AND OUT INTO THE PLAINS STATES TUE NIGHT. EXPECT SOME
SHOWER AND THUNDERSTORM DEVELOPMENT TUE INTO TUE EVENING...THEN
DECREASING. GFS MODEL IS A LITTLE FASTER EXITING THIS FEATURE THAN
THE ECMWF MODEL. IN THE WAKE OF THE DEPARTING SYSTEM A SW FLOW
ALOFT DEVELOPS BY WED MORNING. BOTH MODELS SHOW A WEATHER
DISTURBANCE IMPACTING NW WY WED MORNING THROUGH WED EVENING. THE
BEST CHANCE OF STORMS WILL BE OVER THE NORTH AND NW WITH A LESSER
CHANCE ELSEWHERE. THURSDAY LOOKS DRIER FOR NOW WITH ISOLATED
THUNDERSTORM ACTIVITY OVER THE NORTH. FRIDAY LOOKS MOSTLY DRY AS
WELL WITH ISOLATED STORMS OVER AND NEAR THE MOUNTAINS. NEXT
SATURDAY COULD BE MORE ACTIVE IF THE MODEL TIMING IS CORRECT. FOR
NOW A LOW CHANCE OF SHOWERS AND STORMS. HIGH TEMPS TUESDAY THROUGH
SATURDAY WILL BE ABOUT AVERAGE FOR EARLY AUGUST WITH 80S TO LOW
90S AND 75 TO 85 IN THE FAR WEST VALLEYS.

&&

.AVIATION.../18Z ISSUANCE/

HIGH PRESSURE WILL KEEP VFR CONDITIONS AT AREA TERMINALS THROUGH
18Z SUNDAY. MOSTLY CLEAR SKIES WILL PERSIST...WITH LIGHT WIND. AS
MENTIONED IN PREVIOUS DISCUSSION...SOME DRAINAGE WINDS MAY BUMP UP
WIND SPEEDS AT FOOTHILL TERMINALS AFTER 00Z THIS EVENING...WITH
WIDESPREAD LIGHT WIND RETURNING BY 06Z THIS EVENING.

&&

.FIRE WEATHER...

ENHANCED FIRE DANGER TODAY AND SUNDAY AS HOT AND DRY CONDITIONS WITH
MINIMUM RH VALUES EXPECTED TO REMAIN IN THE LOW TEENS THROUGH THE
WEEKEND ACROSS THE LOWER ELEVATIONS...WITH UPPER TEENS AND 20S OVER
THE MOUNTAINS. EXPECT GENERALLY LIGHT WINDS THROUGH THE WEEKEND.
OTHERWISE...A VERY DRY ATMOSPHERE WITH HIGH PRESSURE AT THE SURFACE
AND ALOFT WILL KEEP LITTLE CHANCE FOR ANY PRECIPITATION TODAY...AND
ONLY ISOLATED AND RELEGATED TO MAINLY A FEW MOUNTAIN OR EASTERN
ZONES SUNDAY. CHANCES WILL INCREASE FOR SCATTERED SHOWERS AND
THUNDERSTORMS FROM MONDAY AFTERNOON THROUGH THE EVENING AS AN UPPER
LEVEL DISTURBANCE COMBINES WITH MONSOONAL MOISTURE.

&&

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

$$

SHORT TERM...BRAUN
LONG TERM...AR
AVIATION...BRANHAM
FIRE WEATHER...BRAUN



000
FXUS65 KRIW 011720
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
1120 AM MDT SAT AUG 1 2015

.SHORT TERM...TODAY THROUGH MONDAY NIGHT

WV IMAGERY SHOWING RIDGE WRN CONUS...TROF ERN CONUS. UPR LVL CENTER
OF THIS HIGH LOCATED OVR NM WITH A STRONGER EMBEDDED WAVE OVR SFC
LOW...VERY TROPICAL LOOKING...NOW ACROSS AZ. A WEAK EMBEDDED SW IS
NOW MOVING DOWN THE EAST SIDE OF THE RIDGE ACROSS NRN/NERN WY WITH
ONLY A FEW SPURIOUS HIGH BASED SHOWERS ACROSS THE NORTH ATTM...WITH
LITTLE PRECIP...IF ANY...ACTUALLY REACHING THE GROUND. SFC HAS
GENERAL WEAK SFC GRAD ACROSS THE FA...WITH AN ALSO WEAK TROF
STRETCHING N/S FROM NCNTRL WY TO CNTRL WY.

HOT AND DRY TODAY SANS PRECIP AT ANY LOCATION IN THE CWA AS DRY AIR
ADVECTS FROM THE WEST OVR THE FA AND ANY SIGNIFICANT MOISTURE IS
HELD AT BAY WELL TO THE SOUTH. SUNDAY...HOTTEST DAY OF THE
PERIOD...WITH WEAK MOISTURE STARTING TO SLOWLY WORK ITS WAY INTO THE
FA THRU THE DAY...ALLOWING FOR LOW CHANCE PRECIP ACROSS FAVORED HIGH
MOUNTAIN RANGES LATER SUNDAY AFTERNOON/EVENING. HOWEVER...IT DOES
LOOK LIKE MOST OF THE PRECIP WILL STILL BE HELD OFF TO THE SOUTH AS
ON SATURDAY. THIS WILL BE A PRECURSOR TO MUCH BETTER CHCS FOR PRECIP
ON MONDAY...AS THE UPR RIDGE AXIS ROTATES CLOCKWISE AND CENTERS OVR
WY WHILE BETTER MONSOONAL MOISTURE STARTS TO FEED ACROSS WY ALONG
WITH WHAT WAS THE AZ DISTURBANCE...MENTIONED ABOVE...MOVING
OVERHEAD. PWS SHOULD BE HIGHER THAN NORMAL...APPROACHING AN INCH IN
SOME PLACES...AND STORM MOTION WILL BE VERY SLOW WITH JET PUSHED OFF
TO THE N AND E...BOTH CONDITIONS TOGETHER GIVING THE POSSIBILITY
FOR AT LEAST ISOLATED FLASH FLOODING.

.LONG TERM...TUESDAY THROUGH SATURDAY

LONG RANGE MODELS MOVE THIS WEATHER SYSTEM ACROSS THE REGION
TUESDAY AND OUT INTO THE PLAINS STATES TUE NIGHT. EXPECT SOME
SHOWER AND THUNDERSTORM DEVELOPMENT TUE INTO TUE EVENING...THEN
DECREASING. GFS MODEL IS A LITTLE FASTER EXITING THIS FEATURE THAN
THE ECMWF MODEL. IN THE WAKE OF THE DEPARTING SYSTEM A SW FLOW
ALOFT DEVELOPS BY WED MORNING. BOTH MODELS SHOW A WEATHER
DISTURBANCE IMPACTING NW WY WED MORNING THROUGH WED EVENING. THE
BEST CHANCE OF STORMS WILL BE OVER THE NORTH AND NW WITH A LESSER
CHANCE ELSEWHERE. THURSDAY LOOKS DRIER FOR NOW WITH ISOLATED
THUNDERSTORM ACTIVITY OVER THE NORTH. FRIDAY LOOKS MOSTLY DRY AS
WELL WITH ISOLATED STORMS OVER AND NEAR THE MOUNTAINS. NEXT
SATURDAY COULD BE MORE ACTIVE IF THE MODEL TIMING IS CORRECT. FOR
NOW A LOW CHANCE OF SHOWERS AND STORMS. HIGH TEMPS TUESDAY THROUGH
SATURDAY WILL BE ABOUT AVERAGE FOR EARLY AUGUST WITH 80S TO LOW
90S AND 75 TO 85 IN THE FAR WEST VALLEYS.

&&

.AVIATION.../18Z ISSUANCE/

HIGH PRESSURE WILL KEEP VFR CONDITIONS AT AREA TERMINALS THROUGH
18Z SUNDAY. MOSTLY CLEAR SKIES WILL PERSIST...WITH LIGHT WIND. AS
MENTIONED IN PREVIOUS DISCUSSION...SOME DRAINAGE WINDS MAY BUMP UP
WIND SPEEDS AT FOOTHILL TERMINALS AFTER 00Z THIS EVENING...WITH
WIDESPREAD LIGHT WIND RETURNING BY 06Z THIS EVENING.

&&

.FIRE WEATHER...

ENHANCED FIRE DANGER TODAY AND SUNDAY AS HOT AND DRY CONDITIONS WITH
MINIMUM RH VALUES EXPECTED TO REMAIN IN THE LOW TEENS THROUGH THE
WEEKEND ACROSS THE LOWER ELEVATIONS...WITH UPPER TEENS AND 20S OVER
THE MOUNTAINS. EXPECT GENERALLY LIGHT WINDS THROUGH THE WEEKEND.
OTHERWISE...A VERY DRY ATMOSPHERE WITH HIGH PRESSURE AT THE SURFACE
AND ALOFT WILL KEEP LITTLE CHANCE FOR ANY PRECIPITATION TODAY...AND
ONLY ISOLATED AND RELEGATED TO MAINLY A FEW MOUNTAIN OR EASTERN
ZONES SUNDAY. CHANCES WILL INCREASE FOR SCATTERED SHOWERS AND
THUNDERSTORMS FROM MONDAY AFTERNOON THROUGH THE EVENING AS AN UPPER
LEVEL DISTURBANCE COMBINES WITH MONSOONAL MOISTURE.

&&

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

$$

SHORT TERM...BRAUN
LONG TERM...AR
AVIATION...BRANHAM
FIRE WEATHER...BRAUN




000
FXUS65 KRIW 011720
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
1120 AM MDT SAT AUG 1 2015

.SHORT TERM...TODAY THROUGH MONDAY NIGHT

WV IMAGERY SHOWING RIDGE WRN CONUS...TROF ERN CONUS. UPR LVL CENTER
OF THIS HIGH LOCATED OVR NM WITH A STRONGER EMBEDDED WAVE OVR SFC
LOW...VERY TROPICAL LOOKING...NOW ACROSS AZ. A WEAK EMBEDDED SW IS
NOW MOVING DOWN THE EAST SIDE OF THE RIDGE ACROSS NRN/NERN WY WITH
ONLY A FEW SPURIOUS HIGH BASED SHOWERS ACROSS THE NORTH ATTM...WITH
LITTLE PRECIP...IF ANY...ACTUALLY REACHING THE GROUND. SFC HAS
GENERAL WEAK SFC GRAD ACROSS THE FA...WITH AN ALSO WEAK TROF
STRETCHING N/S FROM NCNTRL WY TO CNTRL WY.

HOT AND DRY TODAY SANS PRECIP AT ANY LOCATION IN THE CWA AS DRY AIR
ADVECTS FROM THE WEST OVR THE FA AND ANY SIGNIFICANT MOISTURE IS
HELD AT BAY WELL TO THE SOUTH. SUNDAY...HOTTEST DAY OF THE
PERIOD...WITH WEAK MOISTURE STARTING TO SLOWLY WORK ITS WAY INTO THE
FA THRU THE DAY...ALLOWING FOR LOW CHANCE PRECIP ACROSS FAVORED HIGH
MOUNTAIN RANGES LATER SUNDAY AFTERNOON/EVENING. HOWEVER...IT DOES
LOOK LIKE MOST OF THE PRECIP WILL STILL BE HELD OFF TO THE SOUTH AS
ON SATURDAY. THIS WILL BE A PRECURSOR TO MUCH BETTER CHCS FOR PRECIP
ON MONDAY...AS THE UPR RIDGE AXIS ROTATES CLOCKWISE AND CENTERS OVR
WY WHILE BETTER MONSOONAL MOISTURE STARTS TO FEED ACROSS WY ALONG
WITH WHAT WAS THE AZ DISTURBANCE...MENTIONED ABOVE...MOVING
OVERHEAD. PWS SHOULD BE HIGHER THAN NORMAL...APPROACHING AN INCH IN
SOME PLACES...AND STORM MOTION WILL BE VERY SLOW WITH JET PUSHED OFF
TO THE N AND E...BOTH CONDITIONS TOGETHER GIVING THE POSSIBILITY
FOR AT LEAST ISOLATED FLASH FLOODING.

.LONG TERM...TUESDAY THROUGH SATURDAY

LONG RANGE MODELS MOVE THIS WEATHER SYSTEM ACROSS THE REGION
TUESDAY AND OUT INTO THE PLAINS STATES TUE NIGHT. EXPECT SOME
SHOWER AND THUNDERSTORM DEVELOPMENT TUE INTO TUE EVENING...THEN
DECREASING. GFS MODEL IS A LITTLE FASTER EXITING THIS FEATURE THAN
THE ECMWF MODEL. IN THE WAKE OF THE DEPARTING SYSTEM A SW FLOW
ALOFT DEVELOPS BY WED MORNING. BOTH MODELS SHOW A WEATHER
DISTURBANCE IMPACTING NW WY WED MORNING THROUGH WED EVENING. THE
BEST CHANCE OF STORMS WILL BE OVER THE NORTH AND NW WITH A LESSER
CHANCE ELSEWHERE. THURSDAY LOOKS DRIER FOR NOW WITH ISOLATED
THUNDERSTORM ACTIVITY OVER THE NORTH. FRIDAY LOOKS MOSTLY DRY AS
WELL WITH ISOLATED STORMS OVER AND NEAR THE MOUNTAINS. NEXT
SATURDAY COULD BE MORE ACTIVE IF THE MODEL TIMING IS CORRECT. FOR
NOW A LOW CHANCE OF SHOWERS AND STORMS. HIGH TEMPS TUESDAY THROUGH
SATURDAY WILL BE ABOUT AVERAGE FOR EARLY AUGUST WITH 80S TO LOW
90S AND 75 TO 85 IN THE FAR WEST VALLEYS.

&&

.AVIATION.../18Z ISSUANCE/

HIGH PRESSURE WILL KEEP VFR CONDITIONS AT AREA TERMINALS THROUGH
18Z SUNDAY. MOSTLY CLEAR SKIES WILL PERSIST...WITH LIGHT WIND. AS
MENTIONED IN PREVIOUS DISCUSSION...SOME DRAINAGE WINDS MAY BUMP UP
WIND SPEEDS AT FOOTHILL TERMINALS AFTER 00Z THIS EVENING...WITH
WIDESPREAD LIGHT WIND RETURNING BY 06Z THIS EVENING.

&&

.FIRE WEATHER...

ENHANCED FIRE DANGER TODAY AND SUNDAY AS HOT AND DRY CONDITIONS WITH
MINIMUM RH VALUES EXPECTED TO REMAIN IN THE LOW TEENS THROUGH THE
WEEKEND ACROSS THE LOWER ELEVATIONS...WITH UPPER TEENS AND 20S OVER
THE MOUNTAINS. EXPECT GENERALLY LIGHT WINDS THROUGH THE WEEKEND.
OTHERWISE...A VERY DRY ATMOSPHERE WITH HIGH PRESSURE AT THE SURFACE
AND ALOFT WILL KEEP LITTLE CHANCE FOR ANY PRECIPITATION TODAY...AND
ONLY ISOLATED AND RELEGATED TO MAINLY A FEW MOUNTAIN OR EASTERN
ZONES SUNDAY. CHANCES WILL INCREASE FOR SCATTERED SHOWERS AND
THUNDERSTORMS FROM MONDAY AFTERNOON THROUGH THE EVENING AS AN UPPER
LEVEL DISTURBANCE COMBINES WITH MONSOONAL MOISTURE.

&&

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

$$

SHORT TERM...BRAUN
LONG TERM...AR
AVIATION...BRANHAM
FIRE WEATHER...BRAUN




000
FXUS63 KUNR 011715
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
1115 AM MDT SAT AUG 1 2015

.UPDATE...
ISSUED AT 917 AM MDT SAT AUG 1 2015

CURRENT SURFACE ANALYSIS SHOWS FRONTAL BOUNDARY/WARM FRONT NOW
STRETCHING FROM NORTHEAST MT TO CENTRAL SD...WITH A SURFACE TROF
EXTENDING SOUTHWARD ACROSS WESTERN SD. UPPER LEVEL ANALYSIS
CONTINUES TO SHOW RIDGE OVER THE WESTERN CONUS...WITH
NORTHWESTERLY FLOW OVER THE NORTHERN PLAINS. WEAK SHORTWAVE ENERGY
ALOFT...COMBINED WITH LOW LEVEL SOUTHERLY JET AND SUFFICIENT
THETA-E ADVECTION...IS HELPING TO PRODUCE ISOLATED TO SCATTERED
SHOWERS AND THUNDERSTORMS ACROSS MAINLY SOUTH CENTRAL SD AT THIS
POINT. SOME SMALL HAIL IS ACCOMPANYING A COUPLE OF THE STRONGER
STORMS. ELSEWHERE...SKIES ARE MAINLY SUNNY AT THIS TIME. TEMPS ARE
MOSTLY IN THE 70S AT THIS HOUR. SOUTHERLY WINDS ARE BREEZY OVER
PORTIONS OF SOUTH CENTRAL SD IN THE VICINITY OF THE LOW LEVEL
JET...WITH LIGHT AND MORE VARIABLE WINDS FURTHER TO THE WEST.

FOR THE REST OF TODAY...SHOWERS AND THUNDERSTORMS WILL CONTINUE
TO MOVE SOUTH AND EAST ACROSS SOUTH CENTRAL SD THROUGH THE REST OF
THE MORNING. SOME REDEVELOPMENT IS POSSIBLE THERE IN THE
AFTERNOON...SO WILL KEEP LOW CHANCES AT THAT TIME. AN ISOLATED
AFTERNOON SHOWER OR STORM COULD ALSO DEVELOP OVER THE SOUTHERN
HALF OF THE BLACK HILLS AND MOVE SOUTHEAST INTO PARTS OF SOUTHWEST
SD. OTHERWISE...MAINLY SUNNY SKIES SHOULD PERSIST ELSEWHERE
THROUGH THE AFTERNOON. VERY WARM TEMPERATURES CAN BE
EXPECTED...WITH HIGHS IN THE LOW TO MID 90S ACROSS THE
PLAINS...80S IN THE BLACK HILLS.

HAVE UPDATED TO MAKE ADJUSTMENTS TO POPS...MAINLY FOR LATE THIS
MORNING. ALSO LOWERED HIGH TEMPS SLIGHTLY OVER SOUTH CENTRAL SD.

&&

.SHORT TERM...TODAY THROUGH SUNDAY NIGHT
ISSUED AT 228 AM MDT SAT AUG 1 2015

BROAD UPPER RIDGING WILL REMAIN ACROSS THE WRN CONUS THROUGH THE
REMAINDER OF THE WEEKEND. AN UPPER WAVE IS CROSS NCNTRL MT ATTM
PUSHING SE TOWARD THE CWA. SURFACE TROUGH/FRONTAL BOUNDARY HAS
DEVELOPED AHEAD OF THE WAVE OVER ERN MT. GOOD RETURN FLOW OVER THE
CWA IS RESULTING IN ENOUGH THETA E ADVECTION FOR ELEVATED STORMS TO
DEVELOP FROM SCNTRL SD TOWARD MEADE/BUTTE BORDER...AND ALSO NEAR
NEMO/BLACK HAWK. TODAY...FRONTAL BOUNDARY WILL CROSS THE CWA AS
THE UPPER WAVE PUSHES THROUGH THE REGION. S/SW WINDS WILL BECOME
NWRLY BEHIND THE FROPA WHICH WILL BE OF A DRYLINE THAN ANYTHING
ELSE. TEMPS STILL EXPECTED TO RISE INTO THE UPPER 80S TO UPPER
90S. DEWPOINTS WILL DROP BEHIND THE BOUNDARY...ENDING ANY
PROSPECTS FOR CONVECTION THROUGH THE DAY FROM NW TO SE. BY LATE
AFTN...THE ONLY CHANCES FOR STORMS WILL BE NEAR THE NEB
BORDER...AND THESE CHANCES SHOULD END BY EARLY EVNG. DRIER LOW
LEVELS WILL PERSIST INTO SUNDAY WHICH WILL HINDER ANY STORM
DEVELOPMENT. MOSTLY SUNNY SKIES ARE EXPECTED WITH HIGHS REACHING
INTO THE MID 80S TO MID 90S.

.LONG TERM...MONDAY THROUGH FRIDAY
ISSUED AT 228 AM MDT SAT AUG 1 2015

MODELS IN DECENT AGREEMENT WITH THE OVERALL PATTERN THROUGH THE
WEEK. RIDGE BREAKS DOWN MONDAY/EARLY TUESDAY AS WEAK UPPER TROF
LIFTS THROUGH THE CENTRAL ROCKIES INTO THE PLAINS. EAST-SOUTHEAST
LOW LEVEL FLOW WILL BRING INCREASING MOISTURE BOUNDARY LAYER
MOISTURE...WHILE SURGE OF MID LEVEL MOISTURE ARRIVES WITH THE
TROF. MAY BE A FEW ISOLATED THUNDERSTORMS LATE MONDAY FROM THE
BLACK HILLS INTO SOUTH CENTRAL SOUTH DAKOTA. BETTER CHANCE OF
THUNDERSTORMS ON TUESDAY WITH WEAK UPPER TROF ACROSS THE NORTHERN
PLAINS. WEAK RIDGING ACROSS THE AREA FOR WEDNESDAY...THOUGH
SUFFICIENT INSTABILITY FOR A FEW THUNDERSTORMS. CHANCE OF STORMS
WILL CONTINUE THROUGH THE END OF THE WEEK AS UPPER TROF TRACKS
ACROSS THE PACIFIC NORTHWEST/NORTHERN ROCKIES.

&&

.AVIATION...FOR THE 18Z TAFS THROUGH 18Z SUNDAY
ISSUED AT 1113 AM MDT SAT AUG 1 2015

ISOLATED SHOWERS AND THUNDERSTORMS ARE POSSIBLE OVER PARTS OF
SOUTHWESTERN AND SOUTH CENTRAL SOUTH DAKOTA THIS AFTERNOON.
OTHERWISE...VFR CONDITIONS WILL PREVAIL THROUGH SUNDAY.

&&

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

$$

UPDATE...26
SHORT TERM...13
LONG TERM...7
AVIATION...10



000
FXUS63 KUNR 011715
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
1115 AM MDT SAT AUG 1 2015

.UPDATE...
ISSUED AT 917 AM MDT SAT AUG 1 2015

CURRENT SURFACE ANALYSIS SHOWS FRONTAL BOUNDARY/WARM FRONT NOW
STRETCHING FROM NORTHEAST MT TO CENTRAL SD...WITH A SURFACE TROF
EXTENDING SOUTHWARD ACROSS WESTERN SD. UPPER LEVEL ANALYSIS
CONTINUES TO SHOW RIDGE OVER THE WESTERN CONUS...WITH
NORTHWESTERLY FLOW OVER THE NORTHERN PLAINS. WEAK SHORTWAVE ENERGY
ALOFT...COMBINED WITH LOW LEVEL SOUTHERLY JET AND SUFFICIENT
THETA-E ADVECTION...IS HELPING TO PRODUCE ISOLATED TO SCATTERED
SHOWERS AND THUNDERSTORMS ACROSS MAINLY SOUTH CENTRAL SD AT THIS
POINT. SOME SMALL HAIL IS ACCOMPANYING A COUPLE OF THE STRONGER
STORMS. ELSEWHERE...SKIES ARE MAINLY SUNNY AT THIS TIME. TEMPS ARE
MOSTLY IN THE 70S AT THIS HOUR. SOUTHERLY WINDS ARE BREEZY OVER
PORTIONS OF SOUTH CENTRAL SD IN THE VICINITY OF THE LOW LEVEL
JET...WITH LIGHT AND MORE VARIABLE WINDS FURTHER TO THE WEST.

FOR THE REST OF TODAY...SHOWERS AND THUNDERSTORMS WILL CONTINUE
TO MOVE SOUTH AND EAST ACROSS SOUTH CENTRAL SD THROUGH THE REST OF
THE MORNING. SOME REDEVELOPMENT IS POSSIBLE THERE IN THE
AFTERNOON...SO WILL KEEP LOW CHANCES AT THAT TIME. AN ISOLATED
AFTERNOON SHOWER OR STORM COULD ALSO DEVELOP OVER THE SOUTHERN
HALF OF THE BLACK HILLS AND MOVE SOUTHEAST INTO PARTS OF SOUTHWEST
SD. OTHERWISE...MAINLY SUNNY SKIES SHOULD PERSIST ELSEWHERE
THROUGH THE AFTERNOON. VERY WARM TEMPERATURES CAN BE
EXPECTED...WITH HIGHS IN THE LOW TO MID 90S ACROSS THE
PLAINS...80S IN THE BLACK HILLS.

HAVE UPDATED TO MAKE ADJUSTMENTS TO POPS...MAINLY FOR LATE THIS
MORNING. ALSO LOWERED HIGH TEMPS SLIGHTLY OVER SOUTH CENTRAL SD.

&&

.SHORT TERM...TODAY THROUGH SUNDAY NIGHT
ISSUED AT 228 AM MDT SAT AUG 1 2015

BROAD UPPER RIDGING WILL REMAIN ACROSS THE WRN CONUS THROUGH THE
REMAINDER OF THE WEEKEND. AN UPPER WAVE IS CROSS NCNTRL MT ATTM
PUSHING SE TOWARD THE CWA. SURFACE TROUGH/FRONTAL BOUNDARY HAS
DEVELOPED AHEAD OF THE WAVE OVER ERN MT. GOOD RETURN FLOW OVER THE
CWA IS RESULTING IN ENOUGH THETA E ADVECTION FOR ELEVATED STORMS TO
DEVELOP FROM SCNTRL SD TOWARD MEADE/BUTTE BORDER...AND ALSO NEAR
NEMO/BLACK HAWK. TODAY...FRONTAL BOUNDARY WILL CROSS THE CWA AS
THE UPPER WAVE PUSHES THROUGH THE REGION. S/SW WINDS WILL BECOME
NWRLY BEHIND THE FROPA WHICH WILL BE OF A DRYLINE THAN ANYTHING
ELSE. TEMPS STILL EXPECTED TO RISE INTO THE UPPER 80S TO UPPER
90S. DEWPOINTS WILL DROP BEHIND THE BOUNDARY...ENDING ANY
PROSPECTS FOR CONVECTION THROUGH THE DAY FROM NW TO SE. BY LATE
AFTN...THE ONLY CHANCES FOR STORMS WILL BE NEAR THE NEB
BORDER...AND THESE CHANCES SHOULD END BY EARLY EVNG. DRIER LOW
LEVELS WILL PERSIST INTO SUNDAY WHICH WILL HINDER ANY STORM
DEVELOPMENT. MOSTLY SUNNY SKIES ARE EXPECTED WITH HIGHS REACHING
INTO THE MID 80S TO MID 90S.

.LONG TERM...MONDAY THROUGH FRIDAY
ISSUED AT 228 AM MDT SAT AUG 1 2015

MODELS IN DECENT AGREEMENT WITH THE OVERALL PATTERN THROUGH THE
WEEK. RIDGE BREAKS DOWN MONDAY/EARLY TUESDAY AS WEAK UPPER TROF
LIFTS THROUGH THE CENTRAL ROCKIES INTO THE PLAINS. EAST-SOUTHEAST
LOW LEVEL FLOW WILL BRING INCREASING MOISTURE BOUNDARY LAYER
MOISTURE...WHILE SURGE OF MID LEVEL MOISTURE ARRIVES WITH THE
TROF. MAY BE A FEW ISOLATED THUNDERSTORMS LATE MONDAY FROM THE
BLACK HILLS INTO SOUTH CENTRAL SOUTH DAKOTA. BETTER CHANCE OF
THUNDERSTORMS ON TUESDAY WITH WEAK UPPER TROF ACROSS THE NORTHERN
PLAINS. WEAK RIDGING ACROSS THE AREA FOR WEDNESDAY...THOUGH
SUFFICIENT INSTABILITY FOR A FEW THUNDERSTORMS. CHANCE OF STORMS
WILL CONTINUE THROUGH THE END OF THE WEEK AS UPPER TROF TRACKS
ACROSS THE PACIFIC NORTHWEST/NORTHERN ROCKIES.

&&

.AVIATION...FOR THE 18Z TAFS THROUGH 18Z SUNDAY
ISSUED AT 1113 AM MDT SAT AUG 1 2015

ISOLATED SHOWERS AND THUNDERSTORMS ARE POSSIBLE OVER PARTS OF
SOUTHWESTERN AND SOUTH CENTRAL SOUTH DAKOTA THIS AFTERNOON.
OTHERWISE...VFR CONDITIONS WILL PREVAIL THROUGH SUNDAY.

&&

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

$$

UPDATE...26
SHORT TERM...13
LONG TERM...7
AVIATION...10




000
FXUS63 KUNR 011517
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
917 AM MDT SAT AUG 1 2015

.UPDATE...
ISSUED AT 917 AM MDT SAT AUG 1 2015

CURRENT SURFACE ANALYSIS SHOWS FRONTAL BOUNDARY/WARM FRONT NOW
STRETCHING FROM NORTHEAST MT TO CENTRAL SD...WITH A SURFACE TROF
EXTENDING SOUTHWARD ACROSS WESTERN SD. UPPER LEVEL ANALYSIS
CONTINUES TO SHOW RIDGE OVER THE WESTERN CONUS...WITH
NORTHWESTERLY FLOW OVER THE NORTHERN PLAINS. WEAK SHORTWAVE ENERGY
ALOFT...COMBINED WITH LOW LEVEL SOUTHERLY JET AND SUFFICIENT
THETA-E ADVECTION...IS HELPING TO PRODUCE ISOLATED TO SCATTERED
SHOWERS AND THUNDERSTORMS ACROSS MAINLY SOUTH CENTRAL SD AT THIS
POINT. SOME SMALL HAIL IS ACCOMPANYING A COUPLE OF THE STRONGER
STORMS. ELSEWHERE...SKIES ARE MAINLY SUNNY AT THIS TIME. TEMPS ARE
MOSTLY IN THE 70S AT THIS HOUR. SOUTHERLY WINDS ARE BREEZY OVER
PORTIONS OF SOUTH CENTRAL SD IN THE VICINITY OF THE LOW LEVEL
JET...WITH LIGHT AND MORE VARIABLE WINDS FURTHER TO THE WEST.

FOR THE REST OF TODAY...SHOWERS AND THUNDERSTORMS WILL CONTINUE
TO MOVE SOUTH AND EAST ACROSS SOUTH CENTRAL SD THROUGH THE REST OF
THE MORNING. SOME REDEVELOPMENT IS POSSIBLE THERE IN THE
AFTERNOON...SO WILL KEEP LOW CHANCES AT THAT TIME. AN ISOLATED
AFTERNOON SHOWER OR STORM COULD ALSO DEVELOP OVER THE SOUTHERN
HALF OF THE BLACK HILLS AND MOVE SOUTHEAST INTO PARTS OF SOUTHWEST
SD. OTHERWISE...MAINLY SUNNY SKIES SHOULD PERSIST ELSEWHERE
THROUGH THE AFTERNOON. VERY WARM TEMPERATURES CAN BE
EXPECTED...WITH HIGHS IN THE LOW TO MID 90S ACROSS THE
PLAINS...80S IN THE BLACK HILLS.

HAVE UPDATED TO MAKE ADJUSTMENTS TO POPS...MAINLY FOR LATE THIS
MORNING. ALSO LOWERED HIGH TEMPS SLIGHTLY OVER SOUTH CENTRAL SD.

&&

.SHORT TERM...TODAY THROUGH SUNDAY NIGHT
ISSUED AT 228 AM MDT SAT AUG 1 2015

BROAD UPPER RIDGING WILL REMAIN ACROSS THE WRN CONUS THROUGH THE
REMAINDER OF THE WEEKEND. AN UPPER WAVE IS CROSS NCNTRL MT ATTM
PUSHING SE TOWARD THE CWA. SURFACE TROUGH/FRONTAL BOUNDARY HAS
DEVELOPED AHEAD OF THE WAVE OVER ERN MT. GOOD RETURN FLOW OVER THE
CWA IS RESULTING IN ENOUGH THETA E ADVECTION FOR ELEVATED STORMS TO
DEVELOP FROM SCNTRL SD TOWARD MEADE/BUTTE BORDER...AND ALSO NEAR
NEMO/BLACK HAWK. TODAY...FRONTAL BOUNDARY WILL CROSS THE CWA AS
THE UPPER WAVE PUSHES THROUGH THE REGION. S/SW WINDS WILL BECOME
NWRLY BEHIND THE FROPA WHICH WILL BE OF A DRYLINE THAN ANYTHING
ELSE. TEMPS STILL EXPECTED TO RISE INTO THE UPPER 80S TO UPPER
90S. DEWPOINTS WILL DROP BEHIND THE BOUNDARY...ENDING ANY
PROSPECTS FOR CONVECTION THROUGH THE DAY FROM NW TO SE. BY LATE
AFTN...THE ONLY CHANCES FOR STORMS WILL BE NEAR THE NEB
BORDER...AND THESE CHANCES SHOULD END BY EARLY EVNG. DRIER LOW
LEVELS WILL PERSIST INTO SUNDAY WHICH WILL HINDER ANY STORM
DEVELOPMENT. MOSTLY SUNNY SKIES ARE EXPECTED WITH HIGHS REACHING
INTO THE MID 80S TO MID 90S.

.LONG TERM...MONDAY THROUGH FRIDAY
ISSUED AT 228 AM MDT SAT AUG 1 2015

MODELS IN DECENT AGREEMENT WITH THE OVERALL PATTERN THROUGH THE
WEEK. RIDGE BREAKS DOWN MONDAY/EARLY TUESDAY AS WEAK UPPER TROF
LIFTS THROUGH THE CENTRAL ROCKIES INTO THE PLAINS. EAST-SOUTHEAST
LOW LEVEL FLOW WILL BRING INCREASING MOISTURE BOUNDARY LAYER
MOISTURE...WHILE SURGE OF MID LEVEL MOISTURE ARRIVES WITH THE
TROF. MAY BE A FEW ISOLATED THUNDERSTORMS LATE MONDAY FROM THE
BLACK HILLS INTO SOUTH CENTRAL SOUTH DAKOTA. BETTER CHANCE OF
THUNDERSTORMS ON TUESDAY WITH WEAK UPPER TROF ACROSS THE NORTHERN
PLAINS. WEAK RIDGING ACROSS THE AREA FOR WEDNESDAY...THOUGH
SUFFICIENT INSTABILITY FOR A FEW THUNDERSTORMS. CHANCE OF STORMS
WILL CONTINUE THROUGH THE END OF THE WEEK AS UPPER TROF TRACKS
ACROSS THE PACIFIC NORTHWEST/NORTHERN ROCKIES.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 353 AM MDT SAT AUG 1 2015

ISOLATED SHRA/TSRA WILL BE FOUND ACROSS THE AREA TODAY...MAINLY
FROM THE BLACK HILLS INTO SOUTH CENTRAL SOUTH DAKOTA. LCL MVFR
CIGS/IFR VSBY WITH THE STRONGER STORMS. OTHERWISE...VFR CONDITIONS
EXPECTED THROUGH TONIGHT.


&&

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

$$

UPDATE...26
SHORT TERM...13
LONG TERM...7
AVIATION...7



000
FXUS65 KCYS 011043
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
443 AM MDT SAT AUG 1 2015

.SHORT TERM...(TODAY THROUGH MONDAY NIGHT)

ISSUED AT 152 AM MDT SAT AUG 1 2015

TODAY...FLOW ALOFT REMAINS NORTHWEST. IN THE AFTERNOON...NAM PROGS A
LOW LEVEL CONVERGENCE AXIS TO SETUP FROM NEAR CHEYENNE TO NEAR
CHADRON WITH A LOW AND MID LEVEL THETA-E RIDGE AXIS ALSO SETTING UP
SOUTH OF THE CHEYENNE TO CHADRON LINE. LOOKS LIKE ENOUGH LOW LEVEL
CONVERGENCE DESPITE THE WARM TEMPERATURES ALOFT TO SPARK ISOLATED
AFTERNOON THUNDERSTORMS ALONG THE CONVERGENCE AXIS AND WILL CONTINUE
TO PAINT 10 TO 25 PERCENT POPS...DRY ELSEWHERE.

TONIGHT...ISOLATED THUNDERSTORMS SHOULD QUICKLY END IN THE EVENING
WITH LOSS OF DAYTIME HEATING...WITH DECREASING CLOUD COVER.

SUNDAY/SUNDAY NIGHT...AGAIN...WARM TEMPERATURES AT MID LEVELS WILL
LIMIT CONVECTIVE POTENTIAL AND CONVECTIVE DEVELOPMENT.
HOWEVER...WITH A LOW LEVEL INSTABILITY AXIS FROM NEAR GRAND JUNCTION
COLORADO TO DOUGLAS WYOMING...BELIEVE THAT ISOLATED THUNDERSTORMS
WILL BE SPARKED IN THE AFTERNOON OVER MUCH OF ALBANY COUNTY NEAR
LARAMIE AND OVER SOUTHERN LARAMIE COUNTY NEAR CHEYENNE. STORMS
EXPECTED TO END SUNDAY EVENING WITH LOSS OF DAYTIME HEATING.

MONDAY/MONDAY NIGHT...MODELS FORECAST THE LOW AND MID LEVEL
MONSOONAL MOISTURE TO SLIDE ACROSS OUR COUNTIES AND COMBINED WITH A
NEGATIVELY TILTED SHORTWAVE TROUGH ALOFT...WE EXPECT SCATTERED TO
NUMEROUS SHOWERS AND SCATTERED THUNDERSTORMS TO ERUPT IN THE
AFTERNOON AND EVENING...MAINLY ALONG AND WEST OF INTERSTATE 25 NEAR
THE LOW AND MID LEVEL THETA-E RIDGE AXIS.

.LONG TERM...(TUESDAY THROUGH FRIDAY)
ISSUED AT 300 AM MDT SAT AUG 1 2015

STILL A LOT OF FLIP FLOPPING WITH MEDIUM RANGE GUIDANCE ON WHAT IS
GOING TO HAPPEN IN THE LONG TERM. NOW THE GFS IS THE MORE BULLISH ON
POPS AND QPF FOR TUESDAY. ECMWF WAS THE MORE BULLISH 24 HOURS AGO.
LEADS TO LESS CONFIDENCE WITH THESE RUN TO RUN INCONSISTENCIES.

BOTH BRING A SHORTWAVE THROUGH THE CWFA MONDAY NIGHT INTO TUESDAY.
GFS BRINGS THE SHORTWAVE FURTHER NORTH WHILE THE ECMWF HAS THE
SHORTWAVE TRACKING ALONG THE COLORADO/WYOMING BORDER. DECIDED TO
MAINTAIN LOW CHANCE TO SLIGHT CHANCE POPS IN THE FORECAST FOR
TUESDAY WITH THE HOPES THAT RUN TO RUN CONSISTENCY INCREASES IN
ORDER TO RAISE POPS AS THE EVENT DRAWS CLOSER. SHOULD THE GFS
SOLUTION CURRENTLY BEING PROPOSED HOLDS TRUE...PANHANDLE AND
EXTREME SOUTHEAST WYOMING ZONES WOULD BE IN FOR HEAVY RAINFALL.
GFS FORECAST OVER 2 INCHES OF RAIN IN THE PANHANDLE FOR TUESDAY AS
THE FRONT STALLS ALONG THE LARAMIE RANGE.

BOTH MODELS SHOWING A FAIRLY DRY DAY WEDNESDAY AS SHORTWAVE MOVES
EAST AND IS REPLACED WITH UPPER LEVEL RIDGING. SURFACE BOUNDARY
GETS FORCED OUT INTO THE PANHANDLE WEDNESDAY AFTERNOON. MOST OF
SOUTHEAST WYOMING WOULD BE DRY AS WESTERLY WINDS CREATE DRY
DOWNSLOPING CONDITIONS OFF THE LARAMIE RANGE. COULD BE QUITE
BREEZY OUT WEST WEDNESDAY AS GFS 700MB WINDS INCREASE TO 30-35KTS.
IN FACT...THE GFS SHOWS THESE STRONG WESTERLY WINDS CONTINUING FOR
THE REST OF THE WEEK. WE WOULD BE DEALING WITH ELEVATED TO
CRITICAL FIRE WEATHER ISSUES UNDER THIS SCENARIO FOR MUCH OF NEXT
WEEK AS AFTERNOON HUMIDITIES LIKELY TO BECOME CRITICAL.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 441 AM MDT SAT AUG 1 2015

ISOLATED TO WIDELY SCATTERED SHOWERS AND THUNDERSTORMS EXPECTED
ONCE AGAIN THIS AFTERNOON FOR AIRPORTS EAST OF THE LARAMIE RANGE.
GREATEST CONCENTRATION WILL BE IN THE NEBRASKA PANHANDLE. DRY WEST
OF THE LARAMIE RANGE TODAY/THIS EVENING.

&&

.FIRE WEATHER...
ISSUED AT 152 AM MDT SAT AUG 1 2015

LOW AFTERNOON RELATIVE HUMIDITIES WEST OF INTERSTATE
25 TODAY AND SUNDAY...THOUGH FORTUNATELY...WINDS AND WIND GUSTS WILL
REMAIN BELOW CRITERIA FOR A MAJORITY OF LOCATIONS. RAIN CHANCES
INCREASE MONDAY AND TUESDAY AS MONSOONAL MOISTURE CREEPS BACK INTO
OUR COUNTIES.

&&

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

$$

SHORT TERM...RUBIN
LONG TERM...GCC
AVIATION...GCC
FIRE WEATHER...RUBIN




000
FXUS65 KCYS 011043
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
443 AM MDT SAT AUG 1 2015

.SHORT TERM...(TODAY THROUGH MONDAY NIGHT)

ISSUED AT 152 AM MDT SAT AUG 1 2015

TODAY...FLOW ALOFT REMAINS NORTHWEST. IN THE AFTERNOON...NAM PROGS A
LOW LEVEL CONVERGENCE AXIS TO SETUP FROM NEAR CHEYENNE TO NEAR
CHADRON WITH A LOW AND MID LEVEL THETA-E RIDGE AXIS ALSO SETTING UP
SOUTH OF THE CHEYENNE TO CHADRON LINE. LOOKS LIKE ENOUGH LOW LEVEL
CONVERGENCE DESPITE THE WARM TEMPERATURES ALOFT TO SPARK ISOLATED
AFTERNOON THUNDERSTORMS ALONG THE CONVERGENCE AXIS AND WILL CONTINUE
TO PAINT 10 TO 25 PERCENT POPS...DRY ELSEWHERE.

TONIGHT...ISOLATED THUNDERSTORMS SHOULD QUICKLY END IN THE EVENING
WITH LOSS OF DAYTIME HEATING...WITH DECREASING CLOUD COVER.

SUNDAY/SUNDAY NIGHT...AGAIN...WARM TEMPERATURES AT MID LEVELS WILL
LIMIT CONVECTIVE POTENTIAL AND CONVECTIVE DEVELOPMENT.
HOWEVER...WITH A LOW LEVEL INSTABILITY AXIS FROM NEAR GRAND JUNCTION
COLORADO TO DOUGLAS WYOMING...BELIEVE THAT ISOLATED THUNDERSTORMS
WILL BE SPARKED IN THE AFTERNOON OVER MUCH OF ALBANY COUNTY NEAR
LARAMIE AND OVER SOUTHERN LARAMIE COUNTY NEAR CHEYENNE. STORMS
EXPECTED TO END SUNDAY EVENING WITH LOSS OF DAYTIME HEATING.

MONDAY/MONDAY NIGHT...MODELS FORECAST THE LOW AND MID LEVEL
MONSOONAL MOISTURE TO SLIDE ACROSS OUR COUNTIES AND COMBINED WITH A
NEGATIVELY TILTED SHORTWAVE TROUGH ALOFT...WE EXPECT SCATTERED TO
NUMEROUS SHOWERS AND SCATTERED THUNDERSTORMS TO ERUPT IN THE
AFTERNOON AND EVENING...MAINLY ALONG AND WEST OF INTERSTATE 25 NEAR
THE LOW AND MID LEVEL THETA-E RIDGE AXIS.

.LONG TERM...(TUESDAY THROUGH FRIDAY)
ISSUED AT 300 AM MDT SAT AUG 1 2015

STILL A LOT OF FLIP FLOPPING WITH MEDIUM RANGE GUIDANCE ON WHAT IS
GOING TO HAPPEN IN THE LONG TERM. NOW THE GFS IS THE MORE BULLISH ON
POPS AND QPF FOR TUESDAY. ECMWF WAS THE MORE BULLISH 24 HOURS AGO.
LEADS TO LESS CONFIDENCE WITH THESE RUN TO RUN INCONSISTENCIES.

BOTH BRING A SHORTWAVE THROUGH THE CWFA MONDAY NIGHT INTO TUESDAY.
GFS BRINGS THE SHORTWAVE FURTHER NORTH WHILE THE ECMWF HAS THE
SHORTWAVE TRACKING ALONG THE COLORADO/WYOMING BORDER. DECIDED TO
MAINTAIN LOW CHANCE TO SLIGHT CHANCE POPS IN THE FORECAST FOR
TUESDAY WITH THE HOPES THAT RUN TO RUN CONSISTENCY INCREASES IN
ORDER TO RAISE POPS AS THE EVENT DRAWS CLOSER. SHOULD THE GFS
SOLUTION CURRENTLY BEING PROPOSED HOLDS TRUE...PANHANDLE AND
EXTREME SOUTHEAST WYOMING ZONES WOULD BE IN FOR HEAVY RAINFALL.
GFS FORECAST OVER 2 INCHES OF RAIN IN THE PANHANDLE FOR TUESDAY AS
THE FRONT STALLS ALONG THE LARAMIE RANGE.

BOTH MODELS SHOWING A FAIRLY DRY DAY WEDNESDAY AS SHORTWAVE MOVES
EAST AND IS REPLACED WITH UPPER LEVEL RIDGING. SURFACE BOUNDARY
GETS FORCED OUT INTO THE PANHANDLE WEDNESDAY AFTERNOON. MOST OF
SOUTHEAST WYOMING WOULD BE DRY AS WESTERLY WINDS CREATE DRY
DOWNSLOPING CONDITIONS OFF THE LARAMIE RANGE. COULD BE QUITE
BREEZY OUT WEST WEDNESDAY AS GFS 700MB WINDS INCREASE TO 30-35KTS.
IN FACT...THE GFS SHOWS THESE STRONG WESTERLY WINDS CONTINUING FOR
THE REST OF THE WEEK. WE WOULD BE DEALING WITH ELEVATED TO
CRITICAL FIRE WEATHER ISSUES UNDER THIS SCENARIO FOR MUCH OF NEXT
WEEK AS AFTERNOON HUMIDITIES LIKELY TO BECOME CRITICAL.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 441 AM MDT SAT AUG 1 2015

ISOLATED TO WIDELY SCATTERED SHOWERS AND THUNDERSTORMS EXPECTED
ONCE AGAIN THIS AFTERNOON FOR AIRPORTS EAST OF THE LARAMIE RANGE.
GREATEST CONCENTRATION WILL BE IN THE NEBRASKA PANHANDLE. DRY WEST
OF THE LARAMIE RANGE TODAY/THIS EVENING.

&&

.FIRE WEATHER...
ISSUED AT 152 AM MDT SAT AUG 1 2015

LOW AFTERNOON RELATIVE HUMIDITIES WEST OF INTERSTATE
25 TODAY AND SUNDAY...THOUGH FORTUNATELY...WINDS AND WIND GUSTS WILL
REMAIN BELOW CRITERIA FOR A MAJORITY OF LOCATIONS. RAIN CHANCES
INCREASE MONDAY AND TUESDAY AS MONSOONAL MOISTURE CREEPS BACK INTO
OUR COUNTIES.

&&

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

$$

SHORT TERM...RUBIN
LONG TERM...GCC
AVIATION...GCC
FIRE WEATHER...RUBIN



000
FXUS63 KUNR 010953
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
353 AM MDT SAT AUG 1 2015

.SHORT TERM...TODAY THROUGH SUNDAY NIGHT
ISSUED AT 228 AM MDT SAT AUG 1 2015

BROAD UPPER RIDGING WILL REMAIN ACROSS THE WRN CONUS THROUGH THE
REMAINDER OF THE WEEKEND. AN UPPER WAVE IS CROSS NCNTRL MT ATTM
PUSHING SE TOWARD THE CWA. SURFACE TROUGH/FRONTAL BOUNDARY HAS
DEVELOPED AHEAD OF THE WAVE OVER ERN MT. GOOD RETURN FLOW OVER THE
CWA IS RESULTING IN ENOUGH THETA E ADVECTION FOR ELEVATED STORMS TO
DEVELOP FROM SCNTRL SD TOWARD MEADE/BUTTE BORDER...AND ALSO NEAR
NEMO/BLACK HAWK. TODAY...FRONTAL BOUNDARY WILL CROSS THE CWA AS
THE UPPER WAVE PUSHES THROUGH THE REGION. S/SW WINDS WILL BECOME
NWRLY BEHIND THE FROPA WHICH WILL BE OF A DRYLINE THAN ANYTHING
ELSE. TEMPS STILL EXPECTED TO RISE INTO THE UPPER 80S TO UPPER
90S. DEWPOINTS WILL DROP BEHIND THE BOUNDARY...ENDING ANY
PROSPECTS FOR CONVECTION THROUGH THE DAY FROM NW TO SE. BY LATE
AFTN...THE ONLY CHANCES FOR STORMS WILL BE NEAR THE NEB
BORDER...AND THESE CHANCES SHOULD END BY EARLY EVNG. DRIER LOW
LEVELS WILL PERSIST INTO SUNDAY WHICH WILL HINDER ANY STORM
DEVELOPMENT. MOSTLY SUNNY SKIES ARE EXPECTED WITH HIGHS REACHING
INTO THE MID 80S TO MID 90S.

.LONG TERM...MONDAY THROUGH FRIDAY
ISSUED AT 228 AM MDT SAT AUG 1 2015

MODELS IN DECENT AGREEMENT WITH THE OVERALL PATTERN THROUGH THE
WEEK. RIDGE BREAKS DOWN MONDAY/EARLY TUESDAY AS WEAK UPPER TROF
LIFTS THROUGH THE CENTRAL ROCKIES INTO THE PLAINS. EAST-SOUTHEAST
LOW LEVEL FLOW WILL BRING INCREASING MOISTURE BOUNDARY LAYER
MOISTURE...WHILE SURGE OF MID LEVEL MOISTURE ARRIVES WITH THE
TROF. MAY BE A FEW ISOLATED THUNDERSTORMS LATE MONDAY FROM THE
BLACK HILLS INTO SOUTH CENTRAL SOUTH DAKOTA. BETTER CHANCE OF
THUNDERSTORMS ON TUESDAY WITH WEAK UPPER TROF ACROSS THE NORTHERN
PLAINS. WEAK RIDGING ACROSS THE AREA FOR WEDNESDAY...THOUGH
SUFFICIENT INSTABILITY FOR A FEW THUNDERSTORMS. CHANCE OF STORMS
WILL CONTINUE THROUGH THE END OF THE WEEK AS UPPER TROF TRACKS
ACROSS THE PACIFIC NORTHWEST/NORTHERN ROCKIES.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 353 AM MDT SAT AUG 1 2015

ISOLATED SHRA/TSRA WILL BE FOUND ACROSS THE AREA TODAY...MAINLY
FROM THE BLACK HILLS INTO SOUTH CENTRAL SOUTH DAKOTA. LCL MVFR
CIGS/IFR VSBY WITH THE STRONGER STORMS. OTHERWISE...VFR CONDITIONS
EXPECTED THROUGH TONIGHT.

&&

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

$$

SHORT TERM...13
LONG TERM...7
AVIATION...7



000
FXUS63 KUNR 010953
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
353 AM MDT SAT AUG 1 2015

.SHORT TERM...TODAY THROUGH SUNDAY NIGHT
ISSUED AT 228 AM MDT SAT AUG 1 2015

BROAD UPPER RIDGING WILL REMAIN ACROSS THE WRN CONUS THROUGH THE
REMAINDER OF THE WEEKEND. AN UPPER WAVE IS CROSS NCNTRL MT ATTM
PUSHING SE TOWARD THE CWA. SURFACE TROUGH/FRONTAL BOUNDARY HAS
DEVELOPED AHEAD OF THE WAVE OVER ERN MT. GOOD RETURN FLOW OVER THE
CWA IS RESULTING IN ENOUGH THETA E ADVECTION FOR ELEVATED STORMS TO
DEVELOP FROM SCNTRL SD TOWARD MEADE/BUTTE BORDER...AND ALSO NEAR
NEMO/BLACK HAWK. TODAY...FRONTAL BOUNDARY WILL CROSS THE CWA AS
THE UPPER WAVE PUSHES THROUGH THE REGION. S/SW WINDS WILL BECOME
NWRLY BEHIND THE FROPA WHICH WILL BE OF A DRYLINE THAN ANYTHING
ELSE. TEMPS STILL EXPECTED TO RISE INTO THE UPPER 80S TO UPPER
90S. DEWPOINTS WILL DROP BEHIND THE BOUNDARY...ENDING ANY
PROSPECTS FOR CONVECTION THROUGH THE DAY FROM NW TO SE. BY LATE
AFTN...THE ONLY CHANCES FOR STORMS WILL BE NEAR THE NEB
BORDER...AND THESE CHANCES SHOULD END BY EARLY EVNG. DRIER LOW
LEVELS WILL PERSIST INTO SUNDAY WHICH WILL HINDER ANY STORM
DEVELOPMENT. MOSTLY SUNNY SKIES ARE EXPECTED WITH HIGHS REACHING
INTO THE MID 80S TO MID 90S.

.LONG TERM...MONDAY THROUGH FRIDAY
ISSUED AT 228 AM MDT SAT AUG 1 2015

MODELS IN DECENT AGREEMENT WITH THE OVERALL PATTERN THROUGH THE
WEEK. RIDGE BREAKS DOWN MONDAY/EARLY TUESDAY AS WEAK UPPER TROF
LIFTS THROUGH THE CENTRAL ROCKIES INTO THE PLAINS. EAST-SOUTHEAST
LOW LEVEL FLOW WILL BRING INCREASING MOISTURE BOUNDARY LAYER
MOISTURE...WHILE SURGE OF MID LEVEL MOISTURE ARRIVES WITH THE
TROF. MAY BE A FEW ISOLATED THUNDERSTORMS LATE MONDAY FROM THE
BLACK HILLS INTO SOUTH CENTRAL SOUTH DAKOTA. BETTER CHANCE OF
THUNDERSTORMS ON TUESDAY WITH WEAK UPPER TROF ACROSS THE NORTHERN
PLAINS. WEAK RIDGING ACROSS THE AREA FOR WEDNESDAY...THOUGH
SUFFICIENT INSTABILITY FOR A FEW THUNDERSTORMS. CHANCE OF STORMS
WILL CONTINUE THROUGH THE END OF THE WEEK AS UPPER TROF TRACKS
ACROSS THE PACIFIC NORTHWEST/NORTHERN ROCKIES.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 353 AM MDT SAT AUG 1 2015

ISOLATED SHRA/TSRA WILL BE FOUND ACROSS THE AREA TODAY...MAINLY
FROM THE BLACK HILLS INTO SOUTH CENTRAL SOUTH DAKOTA. LCL MVFR
CIGS/IFR VSBY WITH THE STRONGER STORMS. OTHERWISE...VFR CONDITIONS
EXPECTED THROUGH TONIGHT.

&&

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

$$

SHORT TERM...13
LONG TERM...7
AVIATION...7




000
FXUS65 KRIW 010920
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
320 AM MDT SAT AUG 1 2015

.SHORT TERM...TODAY THROUGH MONDAY NIGHT

WV IMAGERY SHOWING RIDGE WRN CONUS...TROF ERN CONUS. UPR LVL CENTER
OF THIS HIGH LOCATED OVR NM WITH A STRONGER EMBEDDED WAVE OVR SFC
LOW...VERY TROPICAL LOOKING...NOW ACROSS AZ. A WEAK EMBEDDED SW IS
NOW MOVING DOWN THE EAST SIDE OF THE RIDGE ACROSS NRN/NERN WY WITH
ONLY A FEW SPURIOUS HIGH BASED SHOWERS ACROSS THE NORTH ATTM...WITH
LITTLE PRECIP...IF ANY...ACTUALLY REACHING THE GROUND. SFC HAS
GENERAL WEAK SFC GRAD ACROSS THE FA...WITH AN ALSO WEAK TROF
STRETCHING N/S FROM NCNTRL WY TO CNTRL WY.

HOT AND DRY TODAY SANS PRECIP AT ANY LOCATION IN THE CWA AS DRY AIR
ADVECTS FROM THE WEST OVR THE FA AND ANY SIGNIFICANT MOISTURE IS
HELD AT BAY WELL TO THE SOUTH. SUNDAY...HOTTEST DAY OF THE
PERIOD...WITH WEAK MOISTURE STARTING TO SLOWLY WORK ITS WAY INTO THE
FA THRU THE DAY...ALLOWING FOR LOW CHANCE PRECIP ACROSS FAVORED HIGH
MOUNTAIN RANGES LATER SUNDAY AFTERNOON/EVENING. HOWEVER...IT DOES
LOOK LIKE MOST OF THE PRECIP WILL STILL BE HELD OFF TO THE SOUTH AS
ON SATURDAY. THIS WILL BE A PRECURSOR TO MUCH BETTER CHCS FOR PRECIP
ON MONDAY...AS THE UPR RIDGE AXIS ROTATES CLOCKWISE AND CENTERS OVR
WY WHILE BETTER MONSOONAL MOISTURE STARTS TO FEED ACROSS WY ALONG
WITH WHAT WAS THE AZ DISTURBANCE...MENTIONED ABOVE...MOVING
OVERHEAD. PWS SHOULD BE HIGHER THAN NORMAL...APPROACHING AN INCH IN
SOME PLACES...AND STORM MOTION WILL BE VERY SLOW WITH JET PUSHED OFF
TO THE N AND E...BOTH CONDITIONS TOGETHER GIVING THE POSSIBILITY
FOR AT LEAST ISOLATED FLASH FLOODING.

.LONG TERM...TUESDAY THROUGH SATURDAY

LONG RANGE MODELS MOVE THIS WEATHER SYSTEM ACROSS THE REGION
TUESDAY AND OUT INTO THE PLAINS STATES TUE NIGHT. EXPECT SOME
SHOWER AND THUNDERSTORM DEVELOPMENT TUE INTO TUE EVENING...THEN
DECREASING. GFS MODEL IS A LITTLE FASTER EXITING THIS FEATURE THAN
THE ECMWF MODEL. IN THE WAKE OF THE DEPARTING SYSTEM A SW FLOW
ALOFT DEVELOPS BY WED MORNING. BOTH MODELS SHOW A WEATHER
DISTURBANCE IMPACTING NW WY WED MORNING THROUGH WED EVENING. THE
BEST CHANCE OF STORMS WILL BE OVER THE NORTH AND NW WITH A LESSER
CHANCE ELSEWHERE. THURSDAY LOOKS DRIER FOR NOW WITH ISOLATED
THUNDERSTORM ACTIVITY OVER THE NORTH. FRIDAY LOOKS MOSTLY DRY AS
WELL WITH ISOLATED STORMS OVER AND NEAR THE MOUNTAINS. NEXT
SATURDAY COULD BE MORE ACTIVE IF THE MODEL TIMING IS CORRECT. FOR
NOW A LOW CHANCE OF SHOWERS AND STORMS. HIGH TEMPS TUESDAY THROUGH
SATURDAY WILL BE ABOUT AVERAGE FOR EARLY AUGUST WITH 80S TO LOW
90S AND 75 TO 85 IN THE FAR WEST VALLEYS.

&&

.AVIATION.../12Z ISSUANCE/

CONDITIONS WILL BE VFR THROUGH 12Z/SUNDAY. UPPER FLOW WILL BE
FROM THE WEST-NORTHWEST WHICH WILL LIMIT THE PUSH OF MOISTURE
FROM THE SOUTH FOR ANOTHER DAY. ABUNDANT SUNSHINE EXPECTED WITH
TEMP/DEW POINT SPREADS IN THE 50F TO 60F RANGE AND MID-LEVEL
MOISTURE LIMITED. DRAINAGE WINDS AROUND 12KTS POSSIBLE BETWEEN
00Z-06Z/SUNDAY AT FOOTHILL TERMINALS. OTHERWISE...SURFACE WIND
WILL BE LESS THAN 12KTS AT ALL TERMINALS.

&&

.FIRE WEATHER...

ENHANCED FIRE DANGER TODAY AND SUNDAY AS HOT AND DRY CONDITIONS WITH
MINIMUM RH VALUES EXPECTED TO REMAIN IN THE LOW TEENS THROUGH THE
WEEKEND ACROSS THE LOWER ELEVATIONS...WITH UPPER TEENS AND 20S OVER
THE MOUNTAINS. EXPECT GENERALLY LIGHT WINDS THROUGH THE WEEKEND.
OTHERWISE...A VERY DRY ATMOSPHERE WITH HIGH PRESSURE AT THE SURFACE
AND ALOFT WILL KEEP LITTLE CHANCE FOR ANY PRECIPITATION TODAY...AND
ONLY ISOLATED AND RELEGATED TO MAINLY A FEW MOUNTAIN OR EASTERN
ZONES SUNDAY. CHANCES WILL INCREASE FOR SCATTERED SHOWERS AND
THUNDERSTORMS FROM MONDAY AFTERNOON THROUGH THE EVENING AS AN UPPER
LEVEL DISTURBANCE COMBINES WITH MONSOONAL MOISTURE.

&&

.RIW WATCHES/WARNINGS/ADVISORIES...NONE

&&

$$

SHORT TERM...BRAUN
LONG TERM...AR
AVIATION...CNJ
FIRE WEATHER...BRAUN



000
FXUS65 KRIW 010920
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
320 AM MDT SAT AUG 1 2015

.SHORT TERM...TODAY THROUGH MONDAY NIGHT

WV IMAGERY SHOWING RIDGE WRN CONUS...TROF ERN CONUS. UPR LVL CENTER
OF THIS HIGH LOCATED OVR NM WITH A STRONGER EMBEDDED WAVE OVR SFC
LOW...VERY TROPICAL LOOKING...NOW ACROSS AZ. A WEAK EMBEDDED SW IS
NOW MOVING DOWN THE EAST SIDE OF THE RIDGE ACROSS NRN/NERN WY WITH
ONLY A FEW SPURIOUS HIGH BASED SHOWERS ACROSS THE NORTH ATTM...WITH
LITTLE PRECIP...IF ANY...ACTUALLY REACHING THE GROUND. SFC HAS
GENERAL WEAK SFC GRAD ACROSS THE FA...WITH AN ALSO WEAK TROF
STRETCHING N/S FROM NCNTRL WY TO CNTRL WY.

HOT AND DRY TODAY SANS PRECIP AT ANY LOCATION IN THE CWA AS DRY AIR
ADVECTS FROM THE WEST OVR THE FA AND ANY SIGNIFICANT MOISTURE IS
HELD AT BAY WELL TO THE SOUTH. SUNDAY...HOTTEST DAY OF THE
PERIOD...WITH WEAK MOISTURE STARTING TO SLOWLY WORK ITS WAY INTO THE
FA THRU THE DAY...ALLOWING FOR LOW CHANCE PRECIP ACROSS FAVORED HIGH
MOUNTAIN RANGES LATER SUNDAY AFTERNOON/EVENING. HOWEVER...IT DOES
LOOK LIKE MOST OF THE PRECIP WILL STILL BE HELD OFF TO THE SOUTH AS
ON SATURDAY. THIS WILL BE A PRECURSOR TO MUCH BETTER CHCS FOR PRECIP
ON MONDAY...AS THE UPR RIDGE AXIS ROTATES CLOCKWISE AND CENTERS OVR
WY WHILE BETTER MONSOONAL MOISTURE STARTS TO FEED ACROSS WY ALONG
WITH WHAT WAS THE AZ DISTURBANCE...MENTIONED ABOVE...MOVING
OVERHEAD. PWS SHOULD BE HIGHER THAN NORMAL...APPROACHING AN INCH IN
SOME PLACES...AND STORM MOTION WILL BE VERY SLOW WITH JET PUSHED OFF
TO THE N AND E...BOTH CONDITIONS TOGETHER GIVING THE POSSIBILITY
FOR AT LEAST ISOLATED FLASH FLOODING.

.LONG TERM...TUESDAY THROUGH SATURDAY

LONG RANGE MODELS MOVE THIS WEATHER SYSTEM ACROSS THE REGION
TUESDAY AND OUT INTO THE PLAINS STATES TUE NIGHT. EXPECT SOME
SHOWER AND THUNDERSTORM DEVELOPMENT TUE INTO TUE EVENING...THEN
DECREASING. GFS MODEL IS A LITTLE FASTER EXITING THIS FEATURE THAN
THE ECMWF MODEL. IN THE WAKE OF THE DEPARTING SYSTEM A SW FLOW
ALOFT DEVELOPS BY WED MORNING. BOTH MODELS SHOW A WEATHER
DISTURBANCE IMPACTING NW WY WED MORNING THROUGH WED EVENING. THE
BEST CHANCE OF STORMS WILL BE OVER THE NORTH AND NW WITH A LESSER
CHANCE ELSEWHERE. THURSDAY LOOKS DRIER FOR NOW WITH ISOLATED
THUNDERSTORM ACTIVITY OVER THE NORTH. FRIDAY LOOKS MOSTLY DRY AS
WELL WITH ISOLATED STORMS OVER AND NEAR THE MOUNTAINS. NEXT
SATURDAY COULD BE MORE ACTIVE IF THE MODEL TIMING IS CORRECT. FOR
NOW A LOW CHANCE OF SHOWERS AND STORMS. HIGH TEMPS TUESDAY THROUGH
SATURDAY WILL BE ABOUT AVERAGE FOR EARLY AUGUST WITH 80S TO LOW
90S AND 75 TO 85 IN THE FAR WEST VALLEYS.

&&

.AVIATION.../12Z ISSUANCE/

CONDITIONS WILL BE VFR THROUGH 12Z/SUNDAY. UPPER FLOW WILL BE
FROM THE WEST-NORTHWEST WHICH WILL LIMIT THE PUSH OF MOISTURE
FROM THE SOUTH FOR ANOTHER DAY. ABUNDANT SUNSHINE EXPECTED WITH
TEMP/DEW POINT SPREADS IN THE 50F TO 60F RANGE AND MID-LEVEL
MOISTURE LIMITED. DRAINAGE WINDS AROUND 12KTS POSSIBLE BETWEEN
00Z-06Z/SUNDAY AT FOOTHILL TERMINALS. OTHERWISE...SURFACE WIND
WILL BE LESS THAN 12KTS AT ALL TERMINALS.

&&

.FIRE WEATHER...

ENHANCED FIRE DANGER TODAY AND SUNDAY AS HOT AND DRY CONDITIONS WITH
MINIMUM RH VALUES EXPECTED TO REMAIN IN THE LOW TEENS THROUGH THE
WEEKEND ACROSS THE LOWER ELEVATIONS...WITH UPPER TEENS AND 20S OVER
THE MOUNTAINS. EXPECT GENERALLY LIGHT WINDS THROUGH THE WEEKEND.
OTHERWISE...A VERY DRY ATMOSPHERE WITH HIGH PRESSURE AT THE SURFACE
AND ALOFT WILL KEEP LITTLE CHANCE FOR ANY PRECIPITATION TODAY...AND
ONLY ISOLATED AND RELEGATED TO MAINLY A FEW MOUNTAIN OR EASTERN
ZONES SUNDAY. CHANCES WILL INCREASE FOR SCATTERED SHOWERS AND
THUNDERSTORMS FROM MONDAY AFTERNOON THROUGH THE EVENING AS AN UPPER
LEVEL DISTURBANCE COMBINES WITH MONSOONAL MOISTURE.

&&

.RIW WATCHES/WARNINGS/ADVISORIES...NONE

&&

$$

SHORT TERM...BRAUN
LONG TERM...AR
AVIATION...CNJ
FIRE WEATHER...BRAUN




000
FXUS63 KUNR 010830
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
230 AM MDT SAT AUG 1 2015

.SHORT TERM...TODAY THROUGH SUNDAY NIGHT
ISSUED AT 228 AM MDT SAT AUG 1 2015

BROAD UPPER RIDGING WILL REMAIN ACROSS THE WRN CONUS THROUGH THE
REMAINDER OF THE WEEKEND. AN UPPER WAVE IS CROSS NCNTRL MT ATTM
PUSHING SE TOWARD THE CWA. SURFACE TROUGH/FRONTAL BOUNDARY HAS
DEVELOPED AHEAD OF THE WAVE OVER ERN MT. GOOD RETURN FLOW OVER THE
CWA IS RESULTING IN ENOUGH THETA E ADVECTION FOR ELEVATED STORMS TO
DEVELOP FROM SCNTRL SD TOWARD MEADE/BUTTE BORDER...AND ALSO NEAR
NEMO/BLACK HAWK. TODAY...FRONTAL BOUNDARY WILL CROSS THE CWA AS
THE UPPER WAVE PUSHES THROUGH THE REGION. S/SW WINDS WILL BECOME
NWRLY BEHIND THE FROPA WHICH WILL BE OF A DRYLINE THAN ANYTHING
ELSE. TEMPS STILL EXPECTED TO RISE INTO THE UPPER 80S TO UPPER
90S. DEWPOINTS WILL DROP BEHIND THE BOUNDARY...ENDING ANY
PROSPECTS FOR CONVECTION THROUGH THE DAY FROM NW TO SE. BY LATE
AFTN...THE ONLY CHANCES FOR STORMS WILL BE NEAR THE NEB
BORDER...AND THESE CHANCES SHOULD END BY EARLY EVNG. DRIER LOW
LEVELS WILL PERSIST INTO SUNDAY WHICH WILL HINDER ANY STORM
DEVELOPMENT. MOSTLY SUNNY SKIES ARE EXPECTED WITH HIGHS REACHING
INTO THE MID 80S TO MID 90S.

.LONG TERM...MONDAY THROUGH FRIDAY
ISSUED AT 228 AM MDT SAT AUG 1 2015

MODELS IN DECENT AGREEMENT WITH THE OVERALL PATTERN THROUGH THE
WEEK. RIDGE BREAKS DOWN MONDAY/EARLY TUESDAY AS WEAK UPPER TROF
LIFTS THROUGH THE CENTRAL ROCKIES INTO THE PLAINS. EAST-SOUTHEAST
LOW LEVEL FLOW WILL BRING INCREASING MOISTURE BOUNDARY LAYER
MOISTURE...WHILE SURGE OF MID LEVEL MOISTURE ARRIVES WITH THE
TROF. MAY BE A FEW ISOLATED THUNDERSTORMS LATE MONDAY FROM THE
BLACK HILLS INTO SOUTH CENTRAL SOUTH DAKOTA. BETTER CHANCE OF
THUNDERSTORMS ON TUESDAY WITH WEAK UPPER TROF ACROSS THE NORTHERN
PLAINS. WEAK RIDGING ACROSS THE AREA FOR WEDNESDAY...THOUGH
SUFFICIENT INSTABILITY FOR A FEW THUNDERSTORMS. CHANCE OF STORMS
WILL CONTINUE THROUGH THE END OF THE WEEK AS UPPER TROF TRACKS
ACROSS THE PACIFIC NORTHWEST/NORTHERN ROCKIES.

&&

.AVIATION...FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT
ISSUED AT 228 AM MDT SAT AUG 1 2015

ISOLATED SHRA/TSRA WILL BE FOUND ACROSS THE AREA TODAY...MAINLY
FROM THE BLACK HILLS INTO SOUTH CENTRAL SOUTH DAKOTA. LCL MVFR
CIGS/IFR VSBY WITH THE STRONGER STORMS. OTHERWISE...VFR CONDITIONS
EXPECTED THROUGH TONIGHT.

&&

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

$$

SHORT TERM...13
LONG TERM...7
AVIATION...7



000
FXUS63 KUNR 010830
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
230 AM MDT SAT AUG 1 2015

.SHORT TERM...TODAY THROUGH SUNDAY NIGHT
ISSUED AT 228 AM MDT SAT AUG 1 2015

BROAD UPPER RIDGING WILL REMAIN ACROSS THE WRN CONUS THROUGH THE
REMAINDER OF THE WEEKEND. AN UPPER WAVE IS CROSS NCNTRL MT ATTM
PUSHING SE TOWARD THE CWA. SURFACE TROUGH/FRONTAL BOUNDARY HAS
DEVELOPED AHEAD OF THE WAVE OVER ERN MT. GOOD RETURN FLOW OVER THE
CWA IS RESULTING IN ENOUGH THETA E ADVECTION FOR ELEVATED STORMS TO
DEVELOP FROM SCNTRL SD TOWARD MEADE/BUTTE BORDER...AND ALSO NEAR
NEMO/BLACK HAWK. TODAY...FRONTAL BOUNDARY WILL CROSS THE CWA AS
THE UPPER WAVE PUSHES THROUGH THE REGION. S/SW WINDS WILL BECOME
NWRLY BEHIND THE FROPA WHICH WILL BE OF A DRYLINE THAN ANYTHING
ELSE. TEMPS STILL EXPECTED TO RISE INTO THE UPPER 80S TO UPPER
90S. DEWPOINTS WILL DROP BEHIND THE BOUNDARY...ENDING ANY
PROSPECTS FOR CONVECTION THROUGH THE DAY FROM NW TO SE. BY LATE
AFTN...THE ONLY CHANCES FOR STORMS WILL BE NEAR THE NEB
BORDER...AND THESE CHANCES SHOULD END BY EARLY EVNG. DRIER LOW
LEVELS WILL PERSIST INTO SUNDAY WHICH WILL HINDER ANY STORM
DEVELOPMENT. MOSTLY SUNNY SKIES ARE EXPECTED WITH HIGHS REACHING
INTO THE MID 80S TO MID 90S.

.LONG TERM...MONDAY THROUGH FRIDAY
ISSUED AT 228 AM MDT SAT AUG 1 2015

MODELS IN DECENT AGREEMENT WITH THE OVERALL PATTERN THROUGH THE
WEEK. RIDGE BREAKS DOWN MONDAY/EARLY TUESDAY AS WEAK UPPER TROF
LIFTS THROUGH THE CENTRAL ROCKIES INTO THE PLAINS. EAST-SOUTHEAST
LOW LEVEL FLOW WILL BRING INCREASING MOISTURE BOUNDARY LAYER
MOISTURE...WHILE SURGE OF MID LEVEL MOISTURE ARRIVES WITH THE
TROF. MAY BE A FEW ISOLATED THUNDERSTORMS LATE MONDAY FROM THE
BLACK HILLS INTO SOUTH CENTRAL SOUTH DAKOTA. BETTER CHANCE OF
THUNDERSTORMS ON TUESDAY WITH WEAK UPPER TROF ACROSS THE NORTHERN
PLAINS. WEAK RIDGING ACROSS THE AREA FOR WEDNESDAY...THOUGH
SUFFICIENT INSTABILITY FOR A FEW THUNDERSTORMS. CHANCE OF STORMS
WILL CONTINUE THROUGH THE END OF THE WEEK AS UPPER TROF TRACKS
ACROSS THE PACIFIC NORTHWEST/NORTHERN ROCKIES.

&&

.AVIATION...FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT
ISSUED AT 228 AM MDT SAT AUG 1 2015

ISOLATED SHRA/TSRA WILL BE FOUND ACROSS THE AREA TODAY...MAINLY
FROM THE BLACK HILLS INTO SOUTH CENTRAL SOUTH DAKOTA. LCL MVFR
CIGS/IFR VSBY WITH THE STRONGER STORMS. OTHERWISE...VFR CONDITIONS
EXPECTED THROUGH TONIGHT.

&&

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

$$

SHORT TERM...13
LONG TERM...7
AVIATION...7




000
FXUS65 KCYS 010812
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
212 AM MDT SAT AUG 1 2015

.SHORT TERM...(TODAY THROUGH MONDAY NIGHT)

ISSUED AT 152 AM MDT SAT AUG 1 2015

TODAY...FLOW ALOFT REMAINS NORTHWEST. IN THE AFTERNOON...NAM PROGS A
LOW LEVEL CONVERGENCE AXIS TO SETUP FROM NEAR CHEYENNE TO NEAR
CHADRON WITH A LOW AND MID LEVEL THETA-E RIDGE AXIS ALSO SETTING UP
SOUTH OF THE CHEYENNE TO CHADRON LINE. LOOKS LIKE ENOUGH LOW LEVEL
CONVERGENCE DESPITE THE WARM TEMPERATURES ALOFT TO SPARK ISOLATED
AFTERNOON THUNDERSTORMS ALONG THE CONVERGENCE AXIS AND WILL CONTINUE
TO PAINT 10 TO 25 PERCENT POPS...DRY ELSEWHERE.

TONIGHT...ISOLATED THUNDERSTORMS SHOULD QUICKLY END IN THE EVENING
WITH LOSS OF DAYTIME HEATING...WITH DECREASING CLOUD COVER.

SUNDAY/SUNDAY NIGHT...AGAIN...WARM TEMPERATURES AT MID LEVELS WILL
LIMIT CONVECTIVE POTENTIAL AND CONVECTIVE DEVELOPMENT.
HOWEVER...WITH A LOW LEVEL INSTABILITY AXIS FROM NEAR GRAND JUNCTION
COLORADO TO DOUGLAS WYOMING...BELIEVE THAT ISOLATED THUNDERSTORMS
WILL BE SPARKED IN THE AFTERNOON OVER MUCH OF ALBANY COUNTY NEAR
LARAMIE AND OVER SOUTHERN LARAMIE COUNTY NEAR CHEYENNE. STORMS
EXPECTED TO END SUNDAY EVENING WITH LOSS OF DAYTIME HEATING.

MONDAY/MONDAY NIGHT...MODELS FORECAST THE LOW AND MID LEVEL
MONSOONAL MOISTURE TO SLIDE ACROSS OUR COUNTIES AND COMBINED WITH A
NEGATIVELY TILTED SHORTWAVE TROUGH ALOFT...WE EXPECT SCATTERED TO
NUMEROUS SHOWERS AND SCATTERED THUNDERSTORMS TO ERUPT IN THE
AFTERNOON AND EVENING...MAINLY ALONG AND WEST OF INTERSTATE 25 NEAR
THE LOW AND MID LEVEL THETA-E RIDGE AXIS.

.LONG TERM...(TUESDAY THROUGH FRIDAY)
ISSUED AT 300 AM MDT SAT AUG 1 2015

STILL A LOT OF FLIP FLOPPING WITH MEDIUM RANGE GUIDANCE ON WHAT IS
GOING TO HAPPEN IN THE LONG TERM. NOW THE GFS IS THE MORE BULLISH ON
POPS AND QPF FOR TUESDAY. ECMWF WAS THE MORE BULLISH 24 HOURS AGO.
LEADS TO LESS CONFIDENCE WITH THESE RUN TO RUN INCONSISTENCIES.

BOTH BRING A SHORTWAVE THROUGH THE CWFA MONDAY NIGHT INTO TUESDAY.
GFS BRINGS THE SHORTWAVE FURTHER NORTH WHILE THE ECMWF HAS THE
SHORTWAVE TRACKING ALONG THE COLORADO/WYOMING BORDER. DECIDED TO
MAINTAIN LOW CHANCE TO SLIGHT CHANCE POPS IN THE FORECAST FOR
TUESDAY WITH THE HOPES THAT RUN TO RUN CONSISTENCY INCREASES IN
ORDER TO RAISE POPS AS THE EVENT DRAWS CLOSER. SHOULD THE GFS
SOLUTION CURRENTLY BEING PROPOSED HOLDS TRUE...PANHANDLE AND
EXTREME SOUTHEAST WYOMING ZONES WOULD BE IN FOR HEAVY RAINFALL.
GFS FORECAST OVER 2 INCHES OF RAIN IN THE PANHANDLE FOR TUESDAY AS
THE FRONT STALLS ALONG THE LARAMIE RANGE.

BOTH MODELS SHOWING A FAIRLY DRY DAY WEDNESDAY AS SHORTWAVE MOVES
EAST AND IS REPLACED WITH UPPER LEVEL RIDGING. SURFACE BOUNDARY
GETS FORCED OUT INTO THE PANHANDLE WEDNESDAY AFTERNOON. MOST OF
SOUTHEAST WYOMING WOULD BE DRY AS WESTERLY WINDS CREATE DRY
DOWNSLOPING CONDITIONS OFF THE LARAMIE RANGE. COULD BE QUITE
BREEZY OUT WEST WEDNESDAY AS GFS 700MB WINDS INCREASE TO 30-35KTS.
IN FACT...THE GFS SHOWS THESE STRONG WESTERLY WINDS CONTINUING FOR
THE REST OF THE WEEK. WE WOULD BE DEALING WITH ELEVATED TO
CRITICAL FIRE WEATHER ISSUES UNDER THIS SCENARIO FOR MUCH OF NEXT
WEEK AS AFTERNOON HUMIDITIES LIKELY TO BECOME CRITICAL.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1107 PM MDT FRI JUL 31 2015

WENT AHEAD AND DROPPED TS WORDING FROM THE KCDR TAF OVERNIGHT AS
MOSAIC RADAR SHOWING THE CONVECTION DEVELOPING FURTHER NORTHEAST
IN SOUTH DAKOTA. WILL CONTINUE TO MONITOR THOUGH AS THE OVERNIGHT
HOURS PROGRESS. VFR CONDITIONS OTHERWISE.

&&

.FIRE WEATHER...
ISSUED AT 152 AM MDT SAT AUG 1 2015

LOW AFTERNOON RELATIVE HUMIDITIES WEST OF INTERSTATE
25 TODAY AND SUNDAY...THOUGH FORTUNATELY...WINDS AND WIND GUSTS WILL
REMAIN BELOW CRITERIA FOR A MAJORITY OF LOCATIONS. RAIN CHANCES
INCREASE MONDAY AND TUESDAY AS MONSOONAL MOISTURE CREEPS BACK INTO
OUR COUNTIES.

&&

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

$$

SHORT TERM...RUBIN
LONG TERM...GCC
AVIATION...GCC
FIRE WEATHER...RUBIN



000
FXUS65 KCYS 010812
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
212 AM MDT SAT AUG 1 2015

.SHORT TERM...(TODAY THROUGH MONDAY NIGHT)

ISSUED AT 152 AM MDT SAT AUG 1 2015

TODAY...FLOW ALOFT REMAINS NORTHWEST. IN THE AFTERNOON...NAM PROGS A
LOW LEVEL CONVERGENCE AXIS TO SETUP FROM NEAR CHEYENNE TO NEAR
CHADRON WITH A LOW AND MID LEVEL THETA-E RIDGE AXIS ALSO SETTING UP
SOUTH OF THE CHEYENNE TO CHADRON LINE. LOOKS LIKE ENOUGH LOW LEVEL
CONVERGENCE DESPITE THE WARM TEMPERATURES ALOFT TO SPARK ISOLATED
AFTERNOON THUNDERSTORMS ALONG THE CONVERGENCE AXIS AND WILL CONTINUE
TO PAINT 10 TO 25 PERCENT POPS...DRY ELSEWHERE.

TONIGHT...ISOLATED THUNDERSTORMS SHOULD QUICKLY END IN THE EVENING
WITH LOSS OF DAYTIME HEATING...WITH DECREASING CLOUD COVER.

SUNDAY/SUNDAY NIGHT...AGAIN...WARM TEMPERATURES AT MID LEVELS WILL
LIMIT CONVECTIVE POTENTIAL AND CONVECTIVE DEVELOPMENT.
HOWEVER...WITH A LOW LEVEL INSTABILITY AXIS FROM NEAR GRAND JUNCTION
COLORADO TO DOUGLAS WYOMING...BELIEVE THAT ISOLATED THUNDERSTORMS
WILL BE SPARKED IN THE AFTERNOON OVER MUCH OF ALBANY COUNTY NEAR
LARAMIE AND OVER SOUTHERN LARAMIE COUNTY NEAR CHEYENNE. STORMS
EXPECTED TO END SUNDAY EVENING WITH LOSS OF DAYTIME HEATING.

MONDAY/MONDAY NIGHT...MODELS FORECAST THE LOW AND MID LEVEL
MONSOONAL MOISTURE TO SLIDE ACROSS OUR COUNTIES AND COMBINED WITH A
NEGATIVELY TILTED SHORTWAVE TROUGH ALOFT...WE EXPECT SCATTERED TO
NUMEROUS SHOWERS AND SCATTERED THUNDERSTORMS TO ERUPT IN THE
AFTERNOON AND EVENING...MAINLY ALONG AND WEST OF INTERSTATE 25 NEAR
THE LOW AND MID LEVEL THETA-E RIDGE AXIS.

.LONG TERM...(TUESDAY THROUGH FRIDAY)
ISSUED AT 300 AM MDT SAT AUG 1 2015

STILL A LOT OF FLIP FLOPPING WITH MEDIUM RANGE GUIDANCE ON WHAT IS
GOING TO HAPPEN IN THE LONG TERM. NOW THE GFS IS THE MORE BULLISH ON
POPS AND QPF FOR TUESDAY. ECMWF WAS THE MORE BULLISH 24 HOURS AGO.
LEADS TO LESS CONFIDENCE WITH THESE RUN TO RUN INCONSISTENCIES.

BOTH BRING A SHORTWAVE THROUGH THE CWFA MONDAY NIGHT INTO TUESDAY.
GFS BRINGS THE SHORTWAVE FURTHER NORTH WHILE THE ECMWF HAS THE
SHORTWAVE TRACKING ALONG THE COLORADO/WYOMING BORDER. DECIDED TO
MAINTAIN LOW CHANCE TO SLIGHT CHANCE POPS IN THE FORECAST FOR
TUESDAY WITH THE HOPES THAT RUN TO RUN CONSISTENCY INCREASES IN
ORDER TO RAISE POPS AS THE EVENT DRAWS CLOSER. SHOULD THE GFS
SOLUTION CURRENTLY BEING PROPOSED HOLDS TRUE...PANHANDLE AND
EXTREME SOUTHEAST WYOMING ZONES WOULD BE IN FOR HEAVY RAINFALL.
GFS FORECAST OVER 2 INCHES OF RAIN IN THE PANHANDLE FOR TUESDAY AS
THE FRONT STALLS ALONG THE LARAMIE RANGE.

BOTH MODELS SHOWING A FAIRLY DRY DAY WEDNESDAY AS SHORTWAVE MOVES
EAST AND IS REPLACED WITH UPPER LEVEL RIDGING. SURFACE BOUNDARY
GETS FORCED OUT INTO THE PANHANDLE WEDNESDAY AFTERNOON. MOST OF
SOUTHEAST WYOMING WOULD BE DRY AS WESTERLY WINDS CREATE DRY
DOWNSLOPING CONDITIONS OFF THE LARAMIE RANGE. COULD BE QUITE
BREEZY OUT WEST WEDNESDAY AS GFS 700MB WINDS INCREASE TO 30-35KTS.
IN FACT...THE GFS SHOWS THESE STRONG WESTERLY WINDS CONTINUING FOR
THE REST OF THE WEEK. WE WOULD BE DEALING WITH ELEVATED TO
CRITICAL FIRE WEATHER ISSUES UNDER THIS SCENARIO FOR MUCH OF NEXT
WEEK AS AFTERNOON HUMIDITIES LIKELY TO BECOME CRITICAL.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1107 PM MDT FRI JUL 31 2015

WENT AHEAD AND DROPPED TS WORDING FROM THE KCDR TAF OVERNIGHT AS
MOSAIC RADAR SHOWING THE CONVECTION DEVELOPING FURTHER NORTHEAST
IN SOUTH DAKOTA. WILL CONTINUE TO MONITOR THOUGH AS THE OVERNIGHT
HOURS PROGRESS. VFR CONDITIONS OTHERWISE.

&&

.FIRE WEATHER...
ISSUED AT 152 AM MDT SAT AUG 1 2015

LOW AFTERNOON RELATIVE HUMIDITIES WEST OF INTERSTATE
25 TODAY AND SUNDAY...THOUGH FORTUNATELY...WINDS AND WIND GUSTS WILL
REMAIN BELOW CRITERIA FOR A MAJORITY OF LOCATIONS. RAIN CHANCES
INCREASE MONDAY AND TUESDAY AS MONSOONAL MOISTURE CREEPS BACK INTO
OUR COUNTIES.

&&

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

$$

SHORT TERM...RUBIN
LONG TERM...GCC
AVIATION...GCC
FIRE WEATHER...RUBIN




000
FXUS65 KRIW 010510
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
1110 PM MDT FRI JUL 31 2015

.SHORT TERM...TONIGHT THROUGH SATURDAY

THE UPPER LEVEL RIDGE IS OVER THE WESTERN US TODAY AND LOOKS TO
REMAIN FOR THE NEXT SEVEN DAYS. HOWEVER...THE DETAILS ARE A BIT
MESSY WITH EMBEDDED MOISTURE AND WEAK SHORT WAVE TROUGHS. FOR
TONIGHT AND SATURDAY...WYOMING WILL BE IN THE NW SECTOR OF THE
RIDGE. ISOLATED CONVECTIVE ACTIVITY LATE THIS AFTERNOON MAY
PERSIST INTO THE EVENING HOURS OVER THE ABSAROKAS AND
BIGHORNS...POTENTIALLY IMPACTING NORTHERN JOHNSON COUNTY. GUIDANCE
INDICATES THE BEST ACTION OVER EASTERN WYOMING AS SOME STORMS HAVE
ALREADY DEVELOPED AROUND CHEYENNE. AS SURFACE LOW PRESSURE
DEVELOPS OVER UTAH OVERNIGHT AND SURFACE HIGH PRESSURE MOVES INTO
MONTANA...LOW LEVEL WINDS ARE EXPECTED TO SHIFT TO THE
NORTHEAST...WITH SOME HIGHER GUSTS POSSIBLE IN SWEETWATER COUNTY.

LOW LEVEL DRYING IS EXPECTED FROM NORTH TO SOUTH ON
SATURDAY...KEEPING CONVECTIVE ACTIVITY TOMORROW WELL CAPPED. THE
ONLY AREA WITH A WEAK POTENTIAL IS AROUND SOUTHERN SWEETWATER
COUNTY WHERE WEAK INSTABILITY AND INCREASED MOISTURE MAY HELP A
COUPLE OF STORMS TO DEVELOP. OTHERWISE SIMILAR TEMPERATURES AND
WINDS ARE EXPECTED ON SATURDAY.

.LONG TERM...SATURDAY NIGHT THROUGH FRIDAY

CONTINUED HIGH PRESSURE WILL LEAVE DRY AND WARM CONDITIONS ACROSS
WESTERN AND CENTRAL WYOMING THROUGH SUNDAY MORNING. A WAVE OF LOW
PRESSURE WILL MOVE ACROSS THE DESERT SOUTHWEST SUNDAY
AFTERNOON...AND BEGIN TO MOVE INTO SOUTHERN WYOMING SUNDAY
AFTERNOON AND EVENING. THIS SYSTEM LOOKS TO HAVE DECENT POTENTIAL
TO INTRODUCE SHOWERS AND THUNDERSTORMS TO THE AREA AS IT MOVES
THROUGH. THE WAVE WILL BE SLOWER TO MOVE THROUGH THE AREA...
SPREADING SHOWER ACTIVITY AS IT MOVES THROUGH...ALONG WITH COOLER
TEMPERATURES. SHOWER AND THUNDERSTORM COVERAGE EXPECTED TO
INCREASE ACROSS MUCH OF THE STATE BY MONDAY AFTERNOON.

THE AXIS OF THE RIDGE OF HIGH PRESSURE WILL MOVE ACROSS MUCH OF
THE STATE BY TUESDAY MORNING...BRINGING A SOUTHWEST FLOW TO THE
AREA. ADDITIONAL PUSHES OF MOISTURE WILL THEN IMPACT THE AREA...KEEPING
AFTERNOON SHOWER AND THUNDERSTORM ACTIVITY PRESENT.

MODELS DIVERGE ON THEIR AGREEMENT WITH THE POTENTIAL FOR ANOTHER
WAVE OF LOW PRESSURE TO IMPACT THE AREA WEDNESDAY INTO THURSDAY.
THE GFS IS MORE AGGRESSIVE WITH ARRIVAL OF THIS SYSTEM PUSHING
THROUGH BY THURSDAY. THE ECMWF IS SLOWER WITH THE PROGRESS OF THIS
SYSTEM...HAVING IT MOVE THROUGH BY FRIDAY MORNING. DEPENDING ON
WHICH SOLUTION THEN IS ACCURATE... FRIDAY WILL EITHER BE UNDER THE
INFLUENCE OF A TRANSITORY RIDGING PATTERN...OR IN A NEAR ZONAL
PATTERN AHEAD OF THE NEXT APPROACHING AREA OF LOW PRESSURE.

&&

.AVIATION.../06Z ISSUANCE/

VFR CONDITIONS ANTICIPATED THROUGH THE FORECAST PERIOD. DRY WEST-
NORTHWEST FLOW ALOFT WILL KEEP THE RETURN OF THE SOUTHERLY MOISTURE
TO THE SOUTH OF THE STATE. TEMP/DEW POINT SPREADS WILL BE 50F TO 60F
SO VERY LITTLE CLOUD COVER. WIND SPEEDS WILL BE LESS THAN 12KTS AT
ALL TERMINALS WITH THE POSSIBLE EXCEPTION OF DRAINAGE WINDS AT
FOOTHILL TERMINALS BETWEEN 00Z-06Z/SUNDAY.

&&

.FIRE WEATHER...

GENERALLY QUIET WEATHER PATTERN THROUGH SUNDAY MORNING OVER THE
AREA WITH NEAR SEASONAL TEMPERATURES AND LOW RELATIVE HUMIDITY AT
THE SURFACE. AFTERNOON RH VALUES IN THE LOW TEENS AND UPPER SINGLE
DIGITS WILL CONTINUE INTO SATURDAY...WITH POOR OVERNIGHT RECOVERY
EXCEPT IN THE VALLEYS OF WESTERN WY. WINDS WILL REMAIN GENERALLY
LIGHT...EXCEPT FOR SOME ENHANCED NORTHEAST FLOW OVER SOUTHERN
WYOMING BOTH FRIDAY NIGHT AND SATURDAY NIGHT DUE TO SURFACE LOW
PRESSURE DEVELOPING OVER THE GREAT BASIN. SATURDAY LOOKS TO BE
MOSTLY CLEAR...WHILE SUNDAY SHOULD SEE INCREASING CLOUDINESS FROM
THE SOUTHWEST...WITH SHOWERS AND ISOLATED THUNDERSTORMS MOVING IN
SUNDAY EVENING. SUNDAY SHOULD SEE ABOVE NORMAL TEMPERATURES IN THE
MID 90S IN THE CENTRAL BASINS.

&&

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

&&

$$

SHORT TERM...MCDONALD
LONG TERM...BRANHAM
AVIATION...CNJ
FIRE WEATHER...MCDONALD



000
FXUS65 KRIW 010510
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
1110 PM MDT FRI JUL 31 2015

.SHORT TERM...TONIGHT THROUGH SATURDAY

THE UPPER LEVEL RIDGE IS OVER THE WESTERN US TODAY AND LOOKS TO
REMAIN FOR THE NEXT SEVEN DAYS. HOWEVER...THE DETAILS ARE A BIT
MESSY WITH EMBEDDED MOISTURE AND WEAK SHORT WAVE TROUGHS. FOR
TONIGHT AND SATURDAY...WYOMING WILL BE IN THE NW SECTOR OF THE
RIDGE. ISOLATED CONVECTIVE ACTIVITY LATE THIS AFTERNOON MAY
PERSIST INTO THE EVENING HOURS OVER THE ABSAROKAS AND
BIGHORNS...POTENTIALLY IMPACTING NORTHERN JOHNSON COUNTY. GUIDANCE
INDICATES THE BEST ACTION OVER EASTERN WYOMING AS SOME STORMS HAVE
ALREADY DEVELOPED AROUND CHEYENNE. AS SURFACE LOW PRESSURE
DEVELOPS OVER UTAH OVERNIGHT AND SURFACE HIGH PRESSURE MOVES INTO
MONTANA...LOW LEVEL WINDS ARE EXPECTED TO SHIFT TO THE
NORTHEAST...WITH SOME HIGHER GUSTS POSSIBLE IN SWEETWATER COUNTY.

LOW LEVEL DRYING IS EXPECTED FROM NORTH TO SOUTH ON
SATURDAY...KEEPING CONVECTIVE ACTIVITY TOMORROW WELL CAPPED. THE
ONLY AREA WITH A WEAK POTENTIAL IS AROUND SOUTHERN SWEETWATER
COUNTY WHERE WEAK INSTABILITY AND INCREASED MOISTURE MAY HELP A
COUPLE OF STORMS TO DEVELOP. OTHERWISE SIMILAR TEMPERATURES AND
WINDS ARE EXPECTED ON SATURDAY.

.LONG TERM...SATURDAY NIGHT THROUGH FRIDAY

CONTINUED HIGH PRESSURE WILL LEAVE DRY AND WARM CONDITIONS ACROSS
WESTERN AND CENTRAL WYOMING THROUGH SUNDAY MORNING. A WAVE OF LOW
PRESSURE WILL MOVE ACROSS THE DESERT SOUTHWEST SUNDAY
AFTERNOON...AND BEGIN TO MOVE INTO SOUTHERN WYOMING SUNDAY
AFTERNOON AND EVENING. THIS SYSTEM LOOKS TO HAVE DECENT POTENTIAL
TO INTRODUCE SHOWERS AND THUNDERSTORMS TO THE AREA AS IT MOVES
THROUGH. THE WAVE WILL BE SLOWER TO MOVE THROUGH THE AREA...
SPREADING SHOWER ACTIVITY AS IT MOVES THROUGH...ALONG WITH COOLER
TEMPERATURES. SHOWER AND THUNDERSTORM COVERAGE EXPECTED TO
INCREASE ACROSS MUCH OF THE STATE BY MONDAY AFTERNOON.

THE AXIS OF THE RIDGE OF HIGH PRESSURE WILL MOVE ACROSS MUCH OF
THE STATE BY TUESDAY MORNING...BRINGING A SOUTHWEST FLOW TO THE
AREA. ADDITIONAL PUSHES OF MOISTURE WILL THEN IMPACT THE AREA...KEEPING
AFTERNOON SHOWER AND THUNDERSTORM ACTIVITY PRESENT.

MODELS DIVERGE ON THEIR AGREEMENT WITH THE POTENTIAL FOR ANOTHER
WAVE OF LOW PRESSURE TO IMPACT THE AREA WEDNESDAY INTO THURSDAY.
THE GFS IS MORE AGGRESSIVE WITH ARRIVAL OF THIS SYSTEM PUSHING
THROUGH BY THURSDAY. THE ECMWF IS SLOWER WITH THE PROGRESS OF THIS
SYSTEM...HAVING IT MOVE THROUGH BY FRIDAY MORNING. DEPENDING ON
WHICH SOLUTION THEN IS ACCURATE... FRIDAY WILL EITHER BE UNDER THE
INFLUENCE OF A TRANSITORY RIDGING PATTERN...OR IN A NEAR ZONAL
PATTERN AHEAD OF THE NEXT APPROACHING AREA OF LOW PRESSURE.

&&

.AVIATION.../06Z ISSUANCE/

VFR CONDITIONS ANTICIPATED THROUGH THE FORECAST PERIOD. DRY WEST-
NORTHWEST FLOW ALOFT WILL KEEP THE RETURN OF THE SOUTHERLY MOISTURE
TO THE SOUTH OF THE STATE. TEMP/DEW POINT SPREADS WILL BE 50F TO 60F
SO VERY LITTLE CLOUD COVER. WIND SPEEDS WILL BE LESS THAN 12KTS AT
ALL TERMINALS WITH THE POSSIBLE EXCEPTION OF DRAINAGE WINDS AT
FOOTHILL TERMINALS BETWEEN 00Z-06Z/SUNDAY.

&&

.FIRE WEATHER...

GENERALLY QUIET WEATHER PATTERN THROUGH SUNDAY MORNING OVER THE
AREA WITH NEAR SEASONAL TEMPERATURES AND LOW RELATIVE HUMIDITY AT
THE SURFACE. AFTERNOON RH VALUES IN THE LOW TEENS AND UPPER SINGLE
DIGITS WILL CONTINUE INTO SATURDAY...WITH POOR OVERNIGHT RECOVERY
EXCEPT IN THE VALLEYS OF WESTERN WY. WINDS WILL REMAIN GENERALLY
LIGHT...EXCEPT FOR SOME ENHANCED NORTHEAST FLOW OVER SOUTHERN
WYOMING BOTH FRIDAY NIGHT AND SATURDAY NIGHT DUE TO SURFACE LOW
PRESSURE DEVELOPING OVER THE GREAT BASIN. SATURDAY LOOKS TO BE
MOSTLY CLEAR...WHILE SUNDAY SHOULD SEE INCREASING CLOUDINESS FROM
THE SOUTHWEST...WITH SHOWERS AND ISOLATED THUNDERSTORMS MOVING IN
SUNDAY EVENING. SUNDAY SHOULD SEE ABOVE NORMAL TEMPERATURES IN THE
MID 90S IN THE CENTRAL BASINS.

&&

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

&&

$$

SHORT TERM...MCDONALD
LONG TERM...BRANHAM
AVIATION...CNJ
FIRE WEATHER...MCDONALD



000
FXUS65 KRIW 010510
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
1110 PM MDT FRI JUL 31 2015

.SHORT TERM...TONIGHT THROUGH SATURDAY

THE UPPER LEVEL RIDGE IS OVER THE WESTERN US TODAY AND LOOKS TO
REMAIN FOR THE NEXT SEVEN DAYS. HOWEVER...THE DETAILS ARE A BIT
MESSY WITH EMBEDDED MOISTURE AND WEAK SHORT WAVE TROUGHS. FOR
TONIGHT AND SATURDAY...WYOMING WILL BE IN THE NW SECTOR OF THE
RIDGE. ISOLATED CONVECTIVE ACTIVITY LATE THIS AFTERNOON MAY
PERSIST INTO THE EVENING HOURS OVER THE ABSAROKAS AND
BIGHORNS...POTENTIALLY IMPACTING NORTHERN JOHNSON COUNTY. GUIDANCE
INDICATES THE BEST ACTION OVER EASTERN WYOMING AS SOME STORMS HAVE
ALREADY DEVELOPED AROUND CHEYENNE. AS SURFACE LOW PRESSURE
DEVELOPS OVER UTAH OVERNIGHT AND SURFACE HIGH PRESSURE MOVES INTO
MONTANA...LOW LEVEL WINDS ARE EXPECTED TO SHIFT TO THE
NORTHEAST...WITH SOME HIGHER GUSTS POSSIBLE IN SWEETWATER COUNTY.

LOW LEVEL DRYING IS EXPECTED FROM NORTH TO SOUTH ON
SATURDAY...KEEPING CONVECTIVE ACTIVITY TOMORROW WELL CAPPED. THE
ONLY AREA WITH A WEAK POTENTIAL IS AROUND SOUTHERN SWEETWATER
COUNTY WHERE WEAK INSTABILITY AND INCREASED MOISTURE MAY HELP A
COUPLE OF STORMS TO DEVELOP. OTHERWISE SIMILAR TEMPERATURES AND
WINDS ARE EXPECTED ON SATURDAY.

.LONG TERM...SATURDAY NIGHT THROUGH FRIDAY

CONTINUED HIGH PRESSURE WILL LEAVE DRY AND WARM CONDITIONS ACROSS
WESTERN AND CENTRAL WYOMING THROUGH SUNDAY MORNING. A WAVE OF LOW
PRESSURE WILL MOVE ACROSS THE DESERT SOUTHWEST SUNDAY
AFTERNOON...AND BEGIN TO MOVE INTO SOUTHERN WYOMING SUNDAY
AFTERNOON AND EVENING. THIS SYSTEM LOOKS TO HAVE DECENT POTENTIAL
TO INTRODUCE SHOWERS AND THUNDERSTORMS TO THE AREA AS IT MOVES
THROUGH. THE WAVE WILL BE SLOWER TO MOVE THROUGH THE AREA...
SPREADING SHOWER ACTIVITY AS IT MOVES THROUGH...ALONG WITH COOLER
TEMPERATURES. SHOWER AND THUNDERSTORM COVERAGE EXPECTED TO
INCREASE ACROSS MUCH OF THE STATE BY MONDAY AFTERNOON.

THE AXIS OF THE RIDGE OF HIGH PRESSURE WILL MOVE ACROSS MUCH OF
THE STATE BY TUESDAY MORNING...BRINGING A SOUTHWEST FLOW TO THE
AREA. ADDITIONAL PUSHES OF MOISTURE WILL THEN IMPACT THE AREA...KEEPING
AFTERNOON SHOWER AND THUNDERSTORM ACTIVITY PRESENT.

MODELS DIVERGE ON THEIR AGREEMENT WITH THE POTENTIAL FOR ANOTHER
WAVE OF LOW PRESSURE TO IMPACT THE AREA WEDNESDAY INTO THURSDAY.
THE GFS IS MORE AGGRESSIVE WITH ARRIVAL OF THIS SYSTEM PUSHING
THROUGH BY THURSDAY. THE ECMWF IS SLOWER WITH THE PROGRESS OF THIS
SYSTEM...HAVING IT MOVE THROUGH BY FRIDAY MORNING. DEPENDING ON
WHICH SOLUTION THEN IS ACCURATE... FRIDAY WILL EITHER BE UNDER THE
INFLUENCE OF A TRANSITORY RIDGING PATTERN...OR IN A NEAR ZONAL
PATTERN AHEAD OF THE NEXT APPROACHING AREA OF LOW PRESSURE.

&&

.AVIATION.../06Z ISSUANCE/

VFR CONDITIONS ANTICIPATED THROUGH THE FORECAST PERIOD. DRY WEST-
NORTHWEST FLOW ALOFT WILL KEEP THE RETURN OF THE SOUTHERLY MOISTURE
TO THE SOUTH OF THE STATE. TEMP/DEW POINT SPREADS WILL BE 50F TO 60F
SO VERY LITTLE CLOUD COVER. WIND SPEEDS WILL BE LESS THAN 12KTS AT
ALL TERMINALS WITH THE POSSIBLE EXCEPTION OF DRAINAGE WINDS AT
FOOTHILL TERMINALS BETWEEN 00Z-06Z/SUNDAY.

&&

.FIRE WEATHER...

GENERALLY QUIET WEATHER PATTERN THROUGH SUNDAY MORNING OVER THE
AREA WITH NEAR SEASONAL TEMPERATURES AND LOW RELATIVE HUMIDITY AT
THE SURFACE. AFTERNOON RH VALUES IN THE LOW TEENS AND UPPER SINGLE
DIGITS WILL CONTINUE INTO SATURDAY...WITH POOR OVERNIGHT RECOVERY
EXCEPT IN THE VALLEYS OF WESTERN WY. WINDS WILL REMAIN GENERALLY
LIGHT...EXCEPT FOR SOME ENHANCED NORTHEAST FLOW OVER SOUTHERN
WYOMING BOTH FRIDAY NIGHT AND SATURDAY NIGHT DUE TO SURFACE LOW
PRESSURE DEVELOPING OVER THE GREAT BASIN. SATURDAY LOOKS TO BE
MOSTLY CLEAR...WHILE SUNDAY SHOULD SEE INCREASING CLOUDINESS FROM
THE SOUTHWEST...WITH SHOWERS AND ISOLATED THUNDERSTORMS MOVING IN
SUNDAY EVENING. SUNDAY SHOULD SEE ABOVE NORMAL TEMPERATURES IN THE
MID 90S IN THE CENTRAL BASINS.

&&

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

&&

$$

SHORT TERM...MCDONALD
LONG TERM...BRANHAM
AVIATION...CNJ
FIRE WEATHER...MCDONALD



000
FXUS65 KRIW 010510
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
1110 PM MDT FRI JUL 31 2015

.SHORT TERM...TONIGHT THROUGH SATURDAY

THE UPPER LEVEL RIDGE IS OVER THE WESTERN US TODAY AND LOOKS TO
REMAIN FOR THE NEXT SEVEN DAYS. HOWEVER...THE DETAILS ARE A BIT
MESSY WITH EMBEDDED MOISTURE AND WEAK SHORT WAVE TROUGHS. FOR
TONIGHT AND SATURDAY...WYOMING WILL BE IN THE NW SECTOR OF THE
RIDGE. ISOLATED CONVECTIVE ACTIVITY LATE THIS AFTERNOON MAY
PERSIST INTO THE EVENING HOURS OVER THE ABSAROKAS AND
BIGHORNS...POTENTIALLY IMPACTING NORTHERN JOHNSON COUNTY. GUIDANCE
INDICATES THE BEST ACTION OVER EASTERN WYOMING AS SOME STORMS HAVE
ALREADY DEVELOPED AROUND CHEYENNE. AS SURFACE LOW PRESSURE
DEVELOPS OVER UTAH OVERNIGHT AND SURFACE HIGH PRESSURE MOVES INTO
MONTANA...LOW LEVEL WINDS ARE EXPECTED TO SHIFT TO THE
NORTHEAST...WITH SOME HIGHER GUSTS POSSIBLE IN SWEETWATER COUNTY.

LOW LEVEL DRYING IS EXPECTED FROM NORTH TO SOUTH ON
SATURDAY...KEEPING CONVECTIVE ACTIVITY TOMORROW WELL CAPPED. THE
ONLY AREA WITH A WEAK POTENTIAL IS AROUND SOUTHERN SWEETWATER
COUNTY WHERE WEAK INSTABILITY AND INCREASED MOISTURE MAY HELP A
COUPLE OF STORMS TO DEVELOP. OTHERWISE SIMILAR TEMPERATURES AND
WINDS ARE EXPECTED ON SATURDAY.

.LONG TERM...SATURDAY NIGHT THROUGH FRIDAY

CONTINUED HIGH PRESSURE WILL LEAVE DRY AND WARM CONDITIONS ACROSS
WESTERN AND CENTRAL WYOMING THROUGH SUNDAY MORNING. A WAVE OF LOW
PRESSURE WILL MOVE ACROSS THE DESERT SOUTHWEST SUNDAY
AFTERNOON...AND BEGIN TO MOVE INTO SOUTHERN WYOMING SUNDAY
AFTERNOON AND EVENING. THIS SYSTEM LOOKS TO HAVE DECENT POTENTIAL
TO INTRODUCE SHOWERS AND THUNDERSTORMS TO THE AREA AS IT MOVES
THROUGH. THE WAVE WILL BE SLOWER TO MOVE THROUGH THE AREA...
SPREADING SHOWER ACTIVITY AS IT MOVES THROUGH...ALONG WITH COOLER
TEMPERATURES. SHOWER AND THUNDERSTORM COVERAGE EXPECTED TO
INCREASE ACROSS MUCH OF THE STATE BY MONDAY AFTERNOON.

THE AXIS OF THE RIDGE OF HIGH PRESSURE WILL MOVE ACROSS MUCH OF
THE STATE BY TUESDAY MORNING...BRINGING A SOUTHWEST FLOW TO THE
AREA. ADDITIONAL PUSHES OF MOISTURE WILL THEN IMPACT THE AREA...KEEPING
AFTERNOON SHOWER AND THUNDERSTORM ACTIVITY PRESENT.

MODELS DIVERGE ON THEIR AGREEMENT WITH THE POTENTIAL FOR ANOTHER
WAVE OF LOW PRESSURE TO IMPACT THE AREA WEDNESDAY INTO THURSDAY.
THE GFS IS MORE AGGRESSIVE WITH ARRIVAL OF THIS SYSTEM PUSHING
THROUGH BY THURSDAY. THE ECMWF IS SLOWER WITH THE PROGRESS OF THIS
SYSTEM...HAVING IT MOVE THROUGH BY FRIDAY MORNING. DEPENDING ON
WHICH SOLUTION THEN IS ACCURATE... FRIDAY WILL EITHER BE UNDER THE
INFLUENCE OF A TRANSITORY RIDGING PATTERN...OR IN A NEAR ZONAL
PATTERN AHEAD OF THE NEXT APPROACHING AREA OF LOW PRESSURE.

&&

.AVIATION.../06Z ISSUANCE/

VFR CONDITIONS ANTICIPATED THROUGH THE FORECAST PERIOD. DRY WEST-
NORTHWEST FLOW ALOFT WILL KEEP THE RETURN OF THE SOUTHERLY MOISTURE
TO THE SOUTH OF THE STATE. TEMP/DEW POINT SPREADS WILL BE 50F TO 60F
SO VERY LITTLE CLOUD COVER. WIND SPEEDS WILL BE LESS THAN 12KTS AT
ALL TERMINALS WITH THE POSSIBLE EXCEPTION OF DRAINAGE WINDS AT
FOOTHILL TERMINALS BETWEEN 00Z-06Z/SUNDAY.

&&

.FIRE WEATHER...

GENERALLY QUIET WEATHER PATTERN THROUGH SUNDAY MORNING OVER THE
AREA WITH NEAR SEASONAL TEMPERATURES AND LOW RELATIVE HUMIDITY AT
THE SURFACE. AFTERNOON RH VALUES IN THE LOW TEENS AND UPPER SINGLE
DIGITS WILL CONTINUE INTO SATURDAY...WITH POOR OVERNIGHT RECOVERY
EXCEPT IN THE VALLEYS OF WESTERN WY. WINDS WILL REMAIN GENERALLY
LIGHT...EXCEPT FOR SOME ENHANCED NORTHEAST FLOW OVER SOUTHERN
WYOMING BOTH FRIDAY NIGHT AND SATURDAY NIGHT DUE TO SURFACE LOW
PRESSURE DEVELOPING OVER THE GREAT BASIN. SATURDAY LOOKS TO BE
MOSTLY CLEAR...WHILE SUNDAY SHOULD SEE INCREASING CLOUDINESS FROM
THE SOUTHWEST...WITH SHOWERS AND ISOLATED THUNDERSTORMS MOVING IN
SUNDAY EVENING. SUNDAY SHOULD SEE ABOVE NORMAL TEMPERATURES IN THE
MID 90S IN THE CENTRAL BASINS.

&&

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

&&

$$

SHORT TERM...MCDONALD
LONG TERM...BRANHAM
AVIATION...CNJ
FIRE WEATHER...MCDONALD



000
FXUS65 KCYS 010509
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
1109 PM MDT FRI JUL 31 2015

.SHORT TERM...(TODAY THRU SUNDAY NIGHT)

VIGOROUS SHOWERS AND THUNDERSTORMS DEVELOPED EARLY THIS AFTERNOON
ALONG THE SOUTHERN LARAMIE RANGE...PINE RIDGE...AND W-E ALONG A
CONVERGENCE BOUNDARY THAT FORMED JUST NORTH OF THE CHEYENNE RIDGE IN
NORTHERN LARAMIE COUNTY. MOIST SOUTHEASTERLY FLOW FED THIS
THUNDERSTORM ACTIVITY WITH SBCAPES INITIALLY IN THE 1000-2000 J/KG
RANGE ACROSS LARAMIE COUNTY AND ALONG THE PINE RIDGE. A FEW STRONGER
PULSE STORMS REMAIN ALONG THE PINE RIDGE AT THIS HOUR...WITH THE
WYOMING ACTIVITY DIMINISHING QUITE A BIT AFTER DROPPING A STRONG
COLD POOL AND PUSHING OUT A WELL DEFINED OUTFLOW BOUNDARY. CAN SEE
THE WESTERN EXTENT OF THIS BOUNDARY EXTENDING N-S ACROSS ALBANY
COUNTY WHICH MAY ALLOW FOR A FEW STORMS TO DEVELOP OUT IN THIS AREA
THROUGH THE LATE AFTERNOON AS WELL. WITH RELATIVELY MOIST LOW AND
MIDLEVELS IN PLACE...COULD SEE MODERATE RAIN AND SMALL HAIL WITH ANY
STRONGER STORMS THAT DEVELOP AS SBCAPES OUTSIDE OF THE COLD POOL ARE
STILL ROUGHLY 1000-2000 J/KG ACCORDING TO SPC MESOANALYSIS. FOR
TONIGHT...MOIST SOUTH-SOUTHEASTERLY SFC FLOW WILL CONTINUE AND THE
NOSE OF THE LLVL JET WILL PUSH UP INTO OUR FAR NORTHERN COUNTIES AND
INTO SOUTH DAKOTA. CANNOT RULE OUT A FEW SHOWERS/STORMS OVERNIGHT IN
THESE AREAS.

A WEAK SFC TROUGH STILL LOOKS TO SLIDE SOUTH ACROSS THE CWA TOMORROW
MORNING THRU THE EARLY AFTERNOON WITH AN ISOLATED STORM OR TWO
POSSIBLE ALONG THE FRONT AS IT ROLLS THROUGH. OTHERWISE...WINDS WILL
SHIFT TO THE NORTH AND WILL FILTER IN DRIER AIR FOR SATURDAY NIGHT
AND EARLY SUNDAY. A STRONGER UPPER LEVEL SYSTEM WILL APPROACH FROM
THE SOUTHWEST ON SUNDAY AFTERNOON AND EVENING...INDUCING PRESSURE
FALLS IN THE HIGH COUNTRY AND REINSTATING MOIST EAST-SOUTHEASTERLY
UPSLOPE FLOW TO THE PLAINS BY THE AFTERNOON. WITH INCREASING LIFT
AND MOISTURE ALOFT AND LLVL  MOIST ADVECTION ACROSS THE
PLAINS...EXPECT ANOTHER ROUND OF SHOWERS AND T-STORMS IN THE
AFTERNOON AND EVENING. THE FOCUS FOR CONVECTION LOOKS TO BE OVER THE
HIGHER PEAKS AND ALONG THE LARAMIE RANGE AND NEARBY EASTERN PLAINS.

.LONG TERM...(MONDAY THROUGH FRIDAY)
ISSUED AT 229 PM MDT FRI JUL 31 2015

LONG RANGE MODELS REMAIN IN POOR AGREEMENT FOR MOST OF NEXT
WEEK...ALTHOUGH OVERALL THERE IS MORE CONFIDENCE IN MONDAYS
FORECAST COMPARED TO 24 HOURS AGO. THE GFS IS IN DECENT AGREEMENT
WITH THE ECMWF AND GEM ON MONDAY...ALL SHOWING THE UPPER LEVEL
RIDGE AXIS BREAKING DOWN AND ALLOWING A VIGOROUS UPPER LEVEL
TROUGH TO PUSH FROM SOUTHWEST TO NORTHEAST ACROSS THE FORECAST
AREA MONDAY AFTERNOON. ALTHOUGH LLVL INSTABILITY APPEARS MARGINAL
AT THIS TIME...THE DISTURBANCE WILL PROVIDE JUST ENOUGH MID TO
UPPER LEVEL DYNAMICS TO TRIGGER AFTERNOON SHOWERS AND
THUNDERSTORMS OVER SOUTHEAST WYOMING AND EVENTUALLY THE HIGH
PLAINS OF WESTERN NEBRASKA THAT EVENING. INCREASED POP BETWEEN 25
TO 45 PERCENT ALONG AND WEST OF I25 WITH SLIGHTLY LOWER VALUES
FURTHER EAST.

THERE IS STILL QUITE A BIT OF UNCERTAINTY WITH NEXT WEEKS
FORECAST PAST MONDAY. NUMEROUS MODEL DIFFERENCES WITH THE TIMING
AND TRACK OF SHORTWAVE DISTURBANCES ALOFT ALONG WITH THE
CONSIDERABLE DIFFERENCES IN THE OVERALL PATTERN LATER IN THE WEEK
(THURSDAY AND FRIDAY) IS THE OVERALL FORECAST ISSUE IN THE LONG
TERM. THE TIMING OF THESE DISTURBANCES ARE KEY IN FORECASTING THE
COVERAGE OF POTENTIAL TSTORMS THIS TIME OF THE YEAR...SO THERE
REMAIN LOW CONFIDENCE IN THE LONG TERM. THE ECMWF IS NOW SHOWING
THE STRONG UPPER LEVEL RIDGE EXTENDING NORTHWARD INTO WYOMING FOR
THE MIDDLE TO LATE PART OF NEXT WEEK...AND NOW THE GFS SHOWS A
BACK DOOR COOL FRONT DIVING SOUTHWARD LATE WEDNESDAY AND INTO
THURSDAY. KEPT FORECAST SLIGHTLY ABOVE CLIMO FOR NOW...WITH 15 TO
20 PERCENT POP EACH DAY ACROSS THE HIGH PLAINS...AND HIGHS IN 80S
TO LOW 90S.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1107 PM MDT FRI JUL 31 2015

WENT AHEAD AND DROPPED TS WORDING FROM THE KCDR TAF OVERNIGHT AS
MOSAIC RADAR SHOWING THE CONVECTION DEVELOPING FURTHER NORTHEAST
IN SOUTH DAKOTA. WILL CONTINUE TO MONITOR THOUGH AS THE OVERNIGHT
HOURS PROGRESS. VFR CONDITIONS OTHERWISE.

&&

.FIRE WEATHER...
ISSUED AT 229 PM MDT FRI JUL 31 2015

ISOLATED TO WIDELY SCATTERED SHOWERS AND THUNDERSTORMS WILL CONTINUE
THROUGH THIS EVENING FOR LOCATIONS WITHIN AND EAST OF FWZ ZONES 307-
308. MUCH OF THIS ACTIVITY IS PRODUCING WETTING RAINFALL. DRY
CONDITIONS WILL RETURN TONIGHT...WITH MORE OF AN ISOLATED COVERAGE
OF SHOWERS AND STORMS POSSIBLE TOMORROW ALONG AND EAST OF THE
LARAMIE RANGE. VERY DRY HUMIDITIES WILL PERSIST THROUGH THE WEEKEND
FOR MUCH OF CARBON COUNTY...BUT WINDS STILL LOOK TO BE RELATIVELY
LIGHT.

&&

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

$$

SHORT TERM...RJM
LONG TERM...TJT
AVIATION...GCC
FIRE WEATHER...RJM




000
FXUS63 KUNR 010240
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
840 PM MDT FRI JUL 31 2015

.UPDATE...
ISSUED AT 828 PM MDT FRI JUL 31 2015

WATER VAPOR IMAGES SHOW SUBTLE SIGNS OF A WEAK SHORT WAVE IN THE
YELLOWSTONE VICINITY...WHICH WOULD CROSS NORTHEASTERN WY AND
SOUTHWESTERN SD AFTER MIDNIGHT. KUDX AND KLNX VAD WIND PROFILERS
SHOWING VEERING WINDS...BUT LOW LEVEL JET HAS NOT DEVELOPED YET...
WHILE RETURN FLOW ON THE SURFACE IS STARTING TO BRING HIGHER
DEWPOINTS TO THE AREA. ISOLATED THUNDERSTORMS MORE LIKELY TO FORM
AFTER MIDNIGHT...WITH BEST CHANCES EAST OF PHP-IEN ALONG A THETA-E
RIDGE THROUGH EARLY MORNING.

&&

.SHORT TERM...THIS EVENING THROUGH SATURDAY NIGHT
ISSUED AT 204 PM MDT FRI JUL 31 2015

A 25-30KT LL JET WILL DEVELOP OVER FAR WRN SD THIS EVENING
INCREASING THE MID-LEVEL THETA-E ADVECTION AND INCREASING THE
INSTABILITY ALOFT. MAY SEE ISOLATED ELEVATED THUNDERSTORMS DEVELOP
OVER FAR NERN WY/THE BLKHILLS THIS EVENING WHICH COULD POSSIBLY
CONTINUE THOUGH MUCH OF THE NIGHT IN THE ELEVATED UNSTABLE
LAYER...MOVING GRADUALLY SOUTHEAST OVERNIGHT. A WEAK FRONTAL
BOUNDARY WILL MOVE SOUTHWARD ACROSS THE FORECAST AREA ON SATURDAY.
DUE TO INSTABILITY AND LL FORCING ALONG AND NEAR THE FRONT WILL
INCLUDE A LOW CHANCE OF THUNDERSTORMS OVER SOUTHWESTERN AND SOUTH
CENTRAL SOUTH DAKOTA THROUGH THE DAY ON SATURDAY. HAVE ALSO
INCLUDED A SLIGHT CHANCE OF THUNDERSTORMS OVER THE CENTRAL AND
SOUTHERN BLACK HILLS ON SATURDAY AFTN AS CONVERGENCE ALONG THE
BOUNDARY COMBINED WITH DIURNAL HEATING MAY BE STRONG ENOUGH TO
OVERCOME THE SUBSIENCE BEHIND THE FRONT. HIGH TEMPERATURES ON THE
PLAINS ON SATURDAY ARE EXPECTED TO RANGE FROM THE UPPER 80S TO THE
UPPER 90S

.LONG TERM...SUNDAY THROUGH FRIDAY
ISSUED AT 204 PM MDT FRI JUL 31 2015

GFS/ECMWF STILL IN DECENT AGREEMENT WITH THE OVERALL
PATTERN FOR MUCH OF NEXT WEEK. HOWEVER...TIMING DIFFERENCES REMAIN
WITH IMPULSES MOVING THROUGH THE NORTHERN PLAINS...ESPECIALLY
FURTHER OUT IN TIME.

SUNDAY WILL BE WARM AND DRY AS UPPER RIDGE BUILDS ACROSS THE HIGH
PLAINS. HIGHS WILL BE IN THE 90S ON THE PLAINS WITH RELATIVE
HUMIDITY DROPPING TO AROUND 15 PERCENT AGAIN OVER NORTHEAST WY AND
FAR WESTERN SD. WINDS SHOULD STAY RELATIVELY LIGHT ACROSS THE AREA.

CHANCES FOR THUNDERSTORMS WILL BEGIN TO INCREASE EARLY IN THE
WEEK...STARTING LATE ON MONDAY...AS RIDGE WEAKENS ENOUGH TO ALLOW A
SERIES OF DISTURBANCES TO CROSS THE REGION. LOW LEVEL MOISTURE WILL
INCREASE AS EAST-SOUTHEAST WINDS BECOME RATHER PERSISTENT ACROSS THE
AREA THROUGH MIDWEEK...ESPECIALLY OVER AND EAST OF THE BLACK HILLS.
TIMING FOR BETTER CHANCES OF STORMS IS STILL UNCERTAIN AT THIS
POINT...BUT THE MIDDLE PART OF THE WEEK LOOKS TO BE THE MOST
FAVORABLE PERIOD. TEMPERATURES WILL BE NEAR AVERAGE THROUGH MUCH OF
THE WEEK.

&&

.AVIATION...FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING
ISSUED AT 529 PM MDT FRI JUL 31 2015

SCT CLDS OVR NERN WY AND BLK HLS WL DISSIPATE THIS EVENING. ISOLD TSTMS
MAY DVLP OVR SWRN SD TONITE AND MOV ACRS SCNTRL SD. LGT WNDS WL SHIFT
TO THE NW SAT MRNG BEHIND A COLD FRONT.


&&

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

$$

UPDATE...55
SHORT TERM...10
LONG TERM...26
AVIATION...55



000
FXUS63 KUNR 010240
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
840 PM MDT FRI JUL 31 2015

.UPDATE...
ISSUED AT 828 PM MDT FRI JUL 31 2015

WATER VAPOR IMAGES SHOW SUBTLE SIGNS OF A WEAK SHORT WAVE IN THE
YELLOWSTONE VICINITY...WHICH WOULD CROSS NORTHEASTERN WY AND
SOUTHWESTERN SD AFTER MIDNIGHT. KUDX AND KLNX VAD WIND PROFILERS
SHOWING VEERING WINDS...BUT LOW LEVEL JET HAS NOT DEVELOPED YET...
WHILE RETURN FLOW ON THE SURFACE IS STARTING TO BRING HIGHER
DEWPOINTS TO THE AREA. ISOLATED THUNDERSTORMS MORE LIKELY TO FORM
AFTER MIDNIGHT...WITH BEST CHANCES EAST OF PHP-IEN ALONG A THETA-E
RIDGE THROUGH EARLY MORNING.

&&

.SHORT TERM...THIS EVENING THROUGH SATURDAY NIGHT
ISSUED AT 204 PM MDT FRI JUL 31 2015

A 25-30KT LL JET WILL DEVELOP OVER FAR WRN SD THIS EVENING
INCREASING THE MID-LEVEL THETA-E ADVECTION AND INCREASING THE
INSTABILITY ALOFT. MAY SEE ISOLATED ELEVATED THUNDERSTORMS DEVELOP
OVER FAR NERN WY/THE BLKHILLS THIS EVENING WHICH COULD POSSIBLY
CONTINUE THOUGH MUCH OF THE NIGHT IN THE ELEVATED UNSTABLE
LAYER...MOVING GRADUALLY SOUTHEAST OVERNIGHT. A WEAK FRONTAL
BOUNDARY WILL MOVE SOUTHWARD ACROSS THE FORECAST AREA ON SATURDAY.
DUE TO INSTABILITY AND LL FORCING ALONG AND NEAR THE FRONT WILL
INCLUDE A LOW CHANCE OF THUNDERSTORMS OVER SOUTHWESTERN AND SOUTH
CENTRAL SOUTH DAKOTA THROUGH THE DAY ON SATURDAY. HAVE ALSO
INCLUDED A SLIGHT CHANCE OF THUNDERSTORMS OVER THE CENTRAL AND
SOUTHERN BLACK HILLS ON SATURDAY AFTN AS CONVERGENCE ALONG THE
BOUNDARY COMBINED WITH DIURNAL HEATING MAY BE STRONG ENOUGH TO
OVERCOME THE SUBSIENCE BEHIND THE FRONT. HIGH TEMPERATURES ON THE
PLAINS ON SATURDAY ARE EXPECTED TO RANGE FROM THE UPPER 80S TO THE
UPPER 90S

.LONG TERM...SUNDAY THROUGH FRIDAY
ISSUED AT 204 PM MDT FRI JUL 31 2015

GFS/ECMWF STILL IN DECENT AGREEMENT WITH THE OVERALL
PATTERN FOR MUCH OF NEXT WEEK. HOWEVER...TIMING DIFFERENCES REMAIN
WITH IMPULSES MOVING THROUGH THE NORTHERN PLAINS...ESPECIALLY
FURTHER OUT IN TIME.

SUNDAY WILL BE WARM AND DRY AS UPPER RIDGE BUILDS ACROSS THE HIGH
PLAINS. HIGHS WILL BE IN THE 90S ON THE PLAINS WITH RELATIVE
HUMIDITY DROPPING TO AROUND 15 PERCENT AGAIN OVER NORTHEAST WY AND
FAR WESTERN SD. WINDS SHOULD STAY RELATIVELY LIGHT ACROSS THE AREA.

CHANCES FOR THUNDERSTORMS WILL BEGIN TO INCREASE EARLY IN THE
WEEK...STARTING LATE ON MONDAY...AS RIDGE WEAKENS ENOUGH TO ALLOW A
SERIES OF DISTURBANCES TO CROSS THE REGION. LOW LEVEL MOISTURE WILL
INCREASE AS EAST-SOUTHEAST WINDS BECOME RATHER PERSISTENT ACROSS THE
AREA THROUGH MIDWEEK...ESPECIALLY OVER AND EAST OF THE BLACK HILLS.
TIMING FOR BETTER CHANCES OF STORMS IS STILL UNCERTAIN AT THIS
POINT...BUT THE MIDDLE PART OF THE WEEK LOOKS TO BE THE MOST
FAVORABLE PERIOD. TEMPERATURES WILL BE NEAR AVERAGE THROUGH MUCH OF
THE WEEK.

&&

.AVIATION...FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING
ISSUED AT 529 PM MDT FRI JUL 31 2015

SCT CLDS OVR NERN WY AND BLK HLS WL DISSIPATE THIS EVENING. ISOLD TSTMS
MAY DVLP OVR SWRN SD TONITE AND MOV ACRS SCNTRL SD. LGT WNDS WL SHIFT
TO THE NW SAT MRNG BEHIND A COLD FRONT.


&&

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

$$

UPDATE...55
SHORT TERM...10
LONG TERM...26
AVIATION...55



000
FXUS63 KUNR 010240
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
840 PM MDT FRI JUL 31 2015

.UPDATE...
ISSUED AT 828 PM MDT FRI JUL 31 2015

WATER VAPOR IMAGES SHOW SUBTLE SIGNS OF A WEAK SHORT WAVE IN THE
YELLOWSTONE VICINITY...WHICH WOULD CROSS NORTHEASTERN WY AND
SOUTHWESTERN SD AFTER MIDNIGHT. KUDX AND KLNX VAD WIND PROFILERS
SHOWING VEERING WINDS...BUT LOW LEVEL JET HAS NOT DEVELOPED YET...
WHILE RETURN FLOW ON THE SURFACE IS STARTING TO BRING HIGHER
DEWPOINTS TO THE AREA. ISOLATED THUNDERSTORMS MORE LIKELY TO FORM
AFTER MIDNIGHT...WITH BEST CHANCES EAST OF PHP-IEN ALONG A THETA-E
RIDGE THROUGH EARLY MORNING.

&&

.SHORT TERM...THIS EVENING THROUGH SATURDAY NIGHT
ISSUED AT 204 PM MDT FRI JUL 31 2015

A 25-30KT LL JET WILL DEVELOP OVER FAR WRN SD THIS EVENING
INCREASING THE MID-LEVEL THETA-E ADVECTION AND INCREASING THE
INSTABILITY ALOFT. MAY SEE ISOLATED ELEVATED THUNDERSTORMS DEVELOP
OVER FAR NERN WY/THE BLKHILLS THIS EVENING WHICH COULD POSSIBLY
CONTINUE THOUGH MUCH OF THE NIGHT IN THE ELEVATED UNSTABLE
LAYER...MOVING GRADUALLY SOUTHEAST OVERNIGHT. A WEAK FRONTAL
BOUNDARY WILL MOVE SOUTHWARD ACROSS THE FORECAST AREA ON SATURDAY.
DUE TO INSTABILITY AND LL FORCING ALONG AND NEAR THE FRONT WILL
INCLUDE A LOW CHANCE OF THUNDERSTORMS OVER SOUTHWESTERN AND SOUTH
CENTRAL SOUTH DAKOTA THROUGH THE DAY ON SATURDAY. HAVE ALSO
INCLUDED A SLIGHT CHANCE OF THUNDERSTORMS OVER THE CENTRAL AND
SOUTHERN BLACK HILLS ON SATURDAY AFTN AS CONVERGENCE ALONG THE
BOUNDARY COMBINED WITH DIURNAL HEATING MAY BE STRONG ENOUGH TO
OVERCOME THE SUBSIENCE BEHIND THE FRONT. HIGH TEMPERATURES ON THE
PLAINS ON SATURDAY ARE EXPECTED TO RANGE FROM THE UPPER 80S TO THE
UPPER 90S

.LONG TERM...SUNDAY THROUGH FRIDAY
ISSUED AT 204 PM MDT FRI JUL 31 2015

GFS/ECMWF STILL IN DECENT AGREEMENT WITH THE OVERALL
PATTERN FOR MUCH OF NEXT WEEK. HOWEVER...TIMING DIFFERENCES REMAIN
WITH IMPULSES MOVING THROUGH THE NORTHERN PLAINS...ESPECIALLY
FURTHER OUT IN TIME.

SUNDAY WILL BE WARM AND DRY AS UPPER RIDGE BUILDS ACROSS THE HIGH
PLAINS. HIGHS WILL BE IN THE 90S ON THE PLAINS WITH RELATIVE
HUMIDITY DROPPING TO AROUND 15 PERCENT AGAIN OVER NORTHEAST WY AND
FAR WESTERN SD. WINDS SHOULD STAY RELATIVELY LIGHT ACROSS THE AREA.

CHANCES FOR THUNDERSTORMS WILL BEGIN TO INCREASE EARLY IN THE
WEEK...STARTING LATE ON MONDAY...AS RIDGE WEAKENS ENOUGH TO ALLOW A
SERIES OF DISTURBANCES TO CROSS THE REGION. LOW LEVEL MOISTURE WILL
INCREASE AS EAST-SOUTHEAST WINDS BECOME RATHER PERSISTENT ACROSS THE
AREA THROUGH MIDWEEK...ESPECIALLY OVER AND EAST OF THE BLACK HILLS.
TIMING FOR BETTER CHANCES OF STORMS IS STILL UNCERTAIN AT THIS
POINT...BUT THE MIDDLE PART OF THE WEEK LOOKS TO BE THE MOST
FAVORABLE PERIOD. TEMPERATURES WILL BE NEAR AVERAGE THROUGH MUCH OF
THE WEEK.

&&

.AVIATION...FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING
ISSUED AT 529 PM MDT FRI JUL 31 2015

SCT CLDS OVR NERN WY AND BLK HLS WL DISSIPATE THIS EVENING. ISOLD TSTMS
MAY DVLP OVR SWRN SD TONITE AND MOV ACRS SCNTRL SD. LGT WNDS WL SHIFT
TO THE NW SAT MRNG BEHIND A COLD FRONT.


&&

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

$$

UPDATE...55
SHORT TERM...10
LONG TERM...26
AVIATION...55




000
FXUS65 KCYS 010028
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
628 PM MDT FRI JUL 31 2015

.SHORT TERM...(TODAY THRU SUNDAY NIGHT)

VIGOROUS SHOWERS AND THUNDERSTORMS DEVELOPED EARLY THIS AFTERNOON
ALONG THE SOUTHERN LARAMIE RANGE...PINE RIDGE...AND W-E ALONG A
CONVERGENCE BOUNDARY THAT FORMED JUST NORTH OF THE CHEYENNE RIDGE IN
NORTHERN LARAMIE COUNTY. MOIST SOUTHEASTERLY FLOW FED THIS
THUNDERSTORM ACTIVITY WITH SBCAPES INITIALLY IN THE 1000-2000 J/KG
RANGE ACROSS LARAMIE COUNTY AND ALONG THE PINE RIDGE. A FEW STRONGER
PULSE STORMS REMAIN ALONG THE PINE RIDGE AT THIS HOUR...WITH THE
WYOMING ACTIVITY DIMINISHING QUITE A BIT AFTER DROPPING A STRONG
COLD POOL AND PUSHING OUT A WELL DEFINED OUTFLOW BOUNDARY. CAN SEE
THE WESTERN EXTENT OF THIS BOUNDARY EXTENDING N-S ACROSS ALBANY
COUNTY WHICH MAY ALLOW FOR A FEW STORMS TO DEVELOP OUT IN THIS AREA
THROUGH THE LATE AFTERNOON AS WELL. WITH RELATIVELY MOIST LOW AND
MIDLEVELS IN PLACE...COULD SEE MODERATE RAIN AND SMALL HAIL WITH ANY
STRONGER STORMS THAT DEVELOP AS SBCAPES OUTSIDE OF THE COLD POOL ARE
STILL ROUGHLY 1000-2000 J/KG ACCORDING TO SPC MESOANALYSIS. FOR
TONIGHT...MOIST SOUTH-SOUTHEASTERLY SFC FLOW WILL CONTINUE AND THE
NOSE OF THE LLVL JET WILL PUSH UP INTO OUR FAR NORTHERN COUNTIES AND
INTO SOUTH DAKOTA. CANNOT RULE OUT A FEW SHOWERS/STORMS OVERNIGHT IN
THESE AREAS.

A WEAK SFC TROUGH STILL LOOKS TO SLIDE SOUTH ACROSS THE CWA TOMORROW
MORNING THRU THE EARLY AFTERNOON WITH AN ISOLATED STORM OR TWO
POSSIBLE ALONG THE FRONT AS IT ROLLS THROUGH. OTHERWISE...WINDS WILL
SHIFT TO THE NORTH AND WILL FILTER IN DRIER AIR FOR SATURDAY NIGHT
AND EARLY SUNDAY. A STRONGER UPPER LEVEL SYSTEM WILL APPROACH FROM
THE SOUTHWEST ON SUNDAY AFTERNOON AND EVENING...INDUCING PRESSURE
FALLS IN THE HIGH COUNTRY AND REINSTATING MOIST EAST-SOUTHEASTERLY
UPSLOPE FLOW TO THE PLAINS BY THE AFTERNOON. WITH INCREASING LIFT
AND MOISTURE ALOFT AND LLVL  MOIST ADVECTION ACROSS THE
PLAINS...EXPECT ANOTHER ROUND OF SHOWERS AND T-STORMS IN THE
AFTERNOON AND EVENING. THE FOCUS FOR CONVECTION LOOKS TO BE OVER THE
HIGHER PEAKS AND ALONG THE LARAMIE RANGE AND NEARBY EASTERN PLAINS.

.LONG TERM...(MONDAY THROUGH FRIDAY)
ISSUED AT 229 PM MDT FRI JUL 31 2015

LONG RANGE MODELS REMAIN IN POOR AGREEMENT FOR MOST OF NEXT
WEEK...ALTHOUGH OVERALL THERE IS MORE CONFIDENCE IN MONDAYS
FORECAST COMPARED TO 24 HOURS AGO. THE GFS IS IN DECENT AGREEMENT
WITH THE ECMWF AND GEM ON MONDAY...ALL SHOWING THE UPPER LEVEL
RIDGE AXIS BREAKING DOWN AND ALLOWING A VIGOROUS UPPER LEVEL
TROUGH TO PUSH FROM SOUTHWEST TO NORTHEAST ACROSS THE FORECAST
AREA MONDAY AFTERNOON. ALTHOUGH LLVL INSTABILITY APPEARS MARGINAL
AT THIS TIME...THE DISTURBANCE WILL PROVIDE JUST ENOUGH MID TO
UPPER LEVEL DYNAMICS TO TRIGGER AFTERNOON SHOWERS AND
THUNDERSTORMS OVER SOUTHEAST WYOMING AND EVENTUALLY THE HIGH
PLAINS OF WESTERN NEBRASKA THAT EVENING. INCREASED POP BETWEEN 25
TO 45 PERCENT ALONG AND WEST OF I25 WITH SLIGHTLY LOWER VALUES
FURTHER EAST.

THERE IS STILL QUITE A BIT OF UNCERTAINTY WITH NEXT WEEKS
FORECAST PAST MONDAY. NUMEROUS MODEL DIFFERENCES WITH THE TIMING
AND TRACK OF SHORTWAVE DISTURBANCES ALOFT ALONG WITH THE
CONSIDERABLE DIFFERENCES IN THE OVERALL PATTERN LATER IN THE WEEK
(THURSDAY AND FRIDAY) IS THE OVERALL FORECAST ISSUE IN THE LONG
TERM. THE TIMING OF THESE DISTURBANCES ARE KEY IN FORECASTING THE
COVERAGE OF POTENTIAL TSTORMS THIS TIME OF THE YEAR...SO THERE
REMAIN LOW CONFIDENCE IN THE LONG TERM. THE ECMWF IS NOW SHOWING
THE STRONG UPPER LEVEL RIDGE EXTENDING NORTHWARD INTO WYOMING FOR
THE MIDDLE TO LATE PART OF NEXT WEEK...AND NOW THE GFS SHOWS A
BACK DOOR COOL FRONT DIVING SOUTHWARD LATE WEDNESDAY AND INTO
THURSDAY. KEPT FORECAST SLIGHTLY ABOVE CLIMO FOR NOW...WITH 15 TO
20 PERCENT POP EACH DAY ACROSS THE HIGH PLAINS...AND HIGHS IN 80S
TO LOW 90S.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 626 PM MDT FRI JUL 31 2015

EXPECT GENERALLY VFR CONDITIONS TO PREVAIL AT AREA TERMINALS THRU
THE PERIOD. THERE IS A POSSIBILITY OF VCTS AT KLAR THRU 01Z AND AT
KCDR 06-12Z. BUT CONFIDENCE IS LOW ENOUGH TO JUSTIFY ONLY VICINITY
MENTION. OTHERWISE...EXPECT SKIES TO CLEAR OUT OVERNIGHT WITH
PERHAPS SOME SHALLOW CU BUILDUPS FOR SATURDAY. THUNDERSTORM
CHANCES ON SATURDAY LOOK LESS THAN TODAY...SO NO MENTION INCLUDED
IN THE TAFS AT THIS TIME.

&&

.FIRE WEATHER...
ISSUED AT 229 PM MDT FRI JUL 31 2015

ISOLATED TO WIDELY SCATTERED SHOWERS AND THUNDERSTORMS WILL CONTINUE
THROUGH THIS EVENING FOR LOCATIONS WITHIN AND EAST OF FWZ ZONES 307-
308. MUCH OF THIS ACTIVITY IS PRODUCING WETTING RAINFALL. DRY
CONDITIONS WILL RETURN TONIGHT...WITH MORE OF AN ISOLATED COVERAGE
OF SHOWERS AND STORMS POSSIBLE TOMORROW ALONG AND EAST OF THE
LARAMIE RANGE. VERY DRY HUMIDITIES WILL PERSIST THROUGH THE WEEKEND
FOR MUCH OF CARBON COUNTY...BUT WINDS STILL LOOK TO BE RELATIVELY
LIGHT.

&&

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

$$

SHORT TERM...RJM
LONG TERM...TJT
AVIATION...CAH
FIRE WEATHER...RJM



000
FXUS65 KCYS 010028
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
628 PM MDT FRI JUL 31 2015

.SHORT TERM...(TODAY THRU SUNDAY NIGHT)

VIGOROUS SHOWERS AND THUNDERSTORMS DEVELOPED EARLY THIS AFTERNOON
ALONG THE SOUTHERN LARAMIE RANGE...PINE RIDGE...AND W-E ALONG A
CONVERGENCE BOUNDARY THAT FORMED JUST NORTH OF THE CHEYENNE RIDGE IN
NORTHERN LARAMIE COUNTY. MOIST SOUTHEASTERLY FLOW FED THIS
THUNDERSTORM ACTIVITY WITH SBCAPES INITIALLY IN THE 1000-2000 J/KG
RANGE ACROSS LARAMIE COUNTY AND ALONG THE PINE RIDGE. A FEW STRONGER
PULSE STORMS REMAIN ALONG THE PINE RIDGE AT THIS HOUR...WITH THE
WYOMING ACTIVITY DIMINISHING QUITE A BIT AFTER DROPPING A STRONG
COLD POOL AND PUSHING OUT A WELL DEFINED OUTFLOW BOUNDARY. CAN SEE
THE WESTERN EXTENT OF THIS BOUNDARY EXTENDING N-S ACROSS ALBANY
COUNTY WHICH MAY ALLOW FOR A FEW STORMS TO DEVELOP OUT IN THIS AREA
THROUGH THE LATE AFTERNOON AS WELL. WITH RELATIVELY MOIST LOW AND
MIDLEVELS IN PLACE...COULD SEE MODERATE RAIN AND SMALL HAIL WITH ANY
STRONGER STORMS THAT DEVELOP AS SBCAPES OUTSIDE OF THE COLD POOL ARE
STILL ROUGHLY 1000-2000 J/KG ACCORDING TO SPC MESOANALYSIS. FOR
TONIGHT...MOIST SOUTH-SOUTHEASTERLY SFC FLOW WILL CONTINUE AND THE
NOSE OF THE LLVL JET WILL PUSH UP INTO OUR FAR NORTHERN COUNTIES AND
INTO SOUTH DAKOTA. CANNOT RULE OUT A FEW SHOWERS/STORMS OVERNIGHT IN
THESE AREAS.

A WEAK SFC TROUGH STILL LOOKS TO SLIDE SOUTH ACROSS THE CWA TOMORROW
MORNING THRU THE EARLY AFTERNOON WITH AN ISOLATED STORM OR TWO
POSSIBLE ALONG THE FRONT AS IT ROLLS THROUGH. OTHERWISE...WINDS WILL
SHIFT TO THE NORTH AND WILL FILTER IN DRIER AIR FOR SATURDAY NIGHT
AND EARLY SUNDAY. A STRONGER UPPER LEVEL SYSTEM WILL APPROACH FROM
THE SOUTHWEST ON SUNDAY AFTERNOON AND EVENING...INDUCING PRESSURE
FALLS IN THE HIGH COUNTRY AND REINSTATING MOIST EAST-SOUTHEASTERLY
UPSLOPE FLOW TO THE PLAINS BY THE AFTERNOON. WITH INCREASING LIFT
AND MOISTURE ALOFT AND LLVL  MOIST ADVECTION ACROSS THE
PLAINS...EXPECT ANOTHER ROUND OF SHOWERS AND T-STORMS IN THE
AFTERNOON AND EVENING. THE FOCUS FOR CONVECTION LOOKS TO BE OVER THE
HIGHER PEAKS AND ALONG THE LARAMIE RANGE AND NEARBY EASTERN PLAINS.

.LONG TERM...(MONDAY THROUGH FRIDAY)
ISSUED AT 229 PM MDT FRI JUL 31 2015

LONG RANGE MODELS REMAIN IN POOR AGREEMENT FOR MOST OF NEXT
WEEK...ALTHOUGH OVERALL THERE IS MORE CONFIDENCE IN MONDAYS
FORECAST COMPARED TO 24 HOURS AGO. THE GFS IS IN DECENT AGREEMENT
WITH THE ECMWF AND GEM ON MONDAY...ALL SHOWING THE UPPER LEVEL
RIDGE AXIS BREAKING DOWN AND ALLOWING A VIGOROUS UPPER LEVEL
TROUGH TO PUSH FROM SOUTHWEST TO NORTHEAST ACROSS THE FORECAST
AREA MONDAY AFTERNOON. ALTHOUGH LLVL INSTABILITY APPEARS MARGINAL
AT THIS TIME...THE DISTURBANCE WILL PROVIDE JUST ENOUGH MID TO
UPPER LEVEL DYNAMICS TO TRIGGER AFTERNOON SHOWERS AND
THUNDERSTORMS OVER SOUTHEAST WYOMING AND EVENTUALLY THE HIGH
PLAINS OF WESTERN NEBRASKA THAT EVENING. INCREASED POP BETWEEN 25
TO 45 PERCENT ALONG AND WEST OF I25 WITH SLIGHTLY LOWER VALUES
FURTHER EAST.

THERE IS STILL QUITE A BIT OF UNCERTAINTY WITH NEXT WEEKS
FORECAST PAST MONDAY. NUMEROUS MODEL DIFFERENCES WITH THE TIMING
AND TRACK OF SHORTWAVE DISTURBANCES ALOFT ALONG WITH THE
CONSIDERABLE DIFFERENCES IN THE OVERALL PATTERN LATER IN THE WEEK
(THURSDAY AND FRIDAY) IS THE OVERALL FORECAST ISSUE IN THE LONG
TERM. THE TIMING OF THESE DISTURBANCES ARE KEY IN FORECASTING THE
COVERAGE OF POTENTIAL TSTORMS THIS TIME OF THE YEAR...SO THERE
REMAIN LOW CONFIDENCE IN THE LONG TERM. THE ECMWF IS NOW SHOWING
THE STRONG UPPER LEVEL RIDGE EXTENDING NORTHWARD INTO WYOMING FOR
THE MIDDLE TO LATE PART OF NEXT WEEK...AND NOW THE GFS SHOWS A
BACK DOOR COOL FRONT DIVING SOUTHWARD LATE WEDNESDAY AND INTO
THURSDAY. KEPT FORECAST SLIGHTLY ABOVE CLIMO FOR NOW...WITH 15 TO
20 PERCENT POP EACH DAY ACROSS THE HIGH PLAINS...AND HIGHS IN 80S
TO LOW 90S.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 626 PM MDT FRI JUL 31 2015

EXPECT GENERALLY VFR CONDITIONS TO PREVAIL AT AREA TERMINALS THRU
THE PERIOD. THERE IS A POSSIBILITY OF VCTS AT KLAR THRU 01Z AND AT
KCDR 06-12Z. BUT CONFIDENCE IS LOW ENOUGH TO JUSTIFY ONLY VICINITY
MENTION. OTHERWISE...EXPECT SKIES TO CLEAR OUT OVERNIGHT WITH
PERHAPS SOME SHALLOW CU BUILDUPS FOR SATURDAY. THUNDERSTORM
CHANCES ON SATURDAY LOOK LESS THAN TODAY...SO NO MENTION INCLUDED
IN THE TAFS AT THIS TIME.

&&

.FIRE WEATHER...
ISSUED AT 229 PM MDT FRI JUL 31 2015

ISOLATED TO WIDELY SCATTERED SHOWERS AND THUNDERSTORMS WILL CONTINUE
THROUGH THIS EVENING FOR LOCATIONS WITHIN AND EAST OF FWZ ZONES 307-
308. MUCH OF THIS ACTIVITY IS PRODUCING WETTING RAINFALL. DRY
CONDITIONS WILL RETURN TONIGHT...WITH MORE OF AN ISOLATED COVERAGE
OF SHOWERS AND STORMS POSSIBLE TOMORROW ALONG AND EAST OF THE
LARAMIE RANGE. VERY DRY HUMIDITIES WILL PERSIST THROUGH THE WEEKEND
FOR MUCH OF CARBON COUNTY...BUT WINDS STILL LOOK TO BE RELATIVELY
LIGHT.

&&

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

$$

SHORT TERM...RJM
LONG TERM...TJT
AVIATION...CAH
FIRE WEATHER...RJM




000
FXUS65 KRIW 312340
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
540 PM MDT FRI JUL 31 2015

.SHORT TERM...TONIGHT THROUGH SATURDAY

THE UPPER LEVEL RIDGE IS OVER THE WESTERN US TODAY AND LOOKS TO
REMAIN FOR THE NEXT SEVEN DAYS. HOWEVER...THE DETAILS ARE A BIT
MESSY WITH EMBEDDED MOISTURE AND WEAK SHORT WAVE TROUGHS. FOR
TONIGHT AND SATURDAY...WYOMING WILL BE IN THE NW SECTOR OF THE
RIDGE. ISOLATED CONVECTIVE ACTIVITY LATE THIS AFTERNOON MAY
PERSIST INTO THE EVENING HOURS OVER THE ABSAROKAS AND
BIGHORNS...POTENTIALLY IMPACTING NORTHERN JOHNSON COUNTY. GUIDANCE
INDICATES THE BEST ACTION OVER EASTERN WYOMING AS SOME STORMS HAVE
ALREADY DEVELOPED AROUND CHEYENNE. AS SURFACE LOW PRESSURE
DEVELOPS OVER UTAH OVERNIGHT AND SURFACE HIGH PRESSURE MOVES INTO
MONTANA...LOW LEVEL WINDS ARE EXPECTED TO SHIFT TO THE
NORTHEAST...WITH SOME HIGHER GUSTS POSSIBLE IN SWEETWATER COUNTY.

LOW LEVEL DRYING IS EXPECTED FROM NORTH TO SOUTH ON
SATURDAY...KEEPING CONVECTIVE ACTIVITY TOMORROW WELL CAPPED. THE
ONLY AREA WITH A WEAK POTENTIAL IS AROUND SOUTHERN SWEETWATER
COUNTY WHERE WEAK INSTABILITY AND INCREASED MOISTURE MAY HELP A
COUPLE OF STORMS TO DEVELOP. OTHERWISE SIMILAR TEMPERATURES AND
WINDS ARE EXPECTED ON SATURDAY.

.LONG TERM...SATURDAY NIGHT THROUGH FRIDAY

CONTINUED HIGH PRESSURE WILL LEAVE DRY AND WARM CONDITIONS ACROSS
WESTERN AND CENTRAL WYOMING THROUGH SUNDAY MORNING. A WAVE OF LOW
PRESSURE WILL MOVE ACROSS THE DESERT SOUTHWEST SUNDAY
AFTERNOON...AND BEGIN TO MOVE INTO SOUTHERN WYOMING SUNDAY
AFTERNOON AND EVENING. THIS SYSTEM LOOKS TO HAVE DECENT POTENTIAL
TO INTRODUCE SHOWERS AND THUNDERSTORMS TO THE AREA AS IT MOVES
THROUGH. THE WAVE WILL BE SLOWER TO MOVE THROUGH THE AREA...
SPREADING SHOWER ACTIVITY AS IT MOVES THROUGH...ALONG WITH COOLER
TEMPERATURES. SHOWER AND THUNDERSTORM COVERAGE EXPECTED TO
INCREASE ACROSS MUCH OF THE STATE BY MONDAY AFTERNOON.

THE AXIS OF THE RIDGE OF HIGH PRESSURE WILL MOVE ACROSS MUCH OF
THE STATE BY TUESDAY MORNING...BRINGING A SOUTHWEST FLOW TO THE
AREA. ADDITIONAL PUSHES OF MOISTURE WILL THEN IMPACT THE AREA...KEEPING
AFTERNOON SHOWER AND THUNDERSTORM ACTIVITY PRESENT.

MODELS DIVERGE ON THEIR AGREEMENT WITH THE POTENTIAL FOR ANOTHER
WAVE OF LOW PRESSURE TO IMPACT THE AREA WEDNESDAY INTO THURSDAY.
THE GFS IS MORE AGGRESSIVE WITH ARRIVAL OF THIS SYSTEM PUSHING
THROUGH BY THURSDAY. THE ECMWF IS SLOWER WITH THE PROGRESS OF THIS
SYSTEM...HAVING IT MOVE THROUGH BY FRIDAY MORNING. DEPENDING ON
WHICH SOLUTION THEN IS ACCURATE... FRIDAY WILL EITHER BE UNDER THE
INFLUENCE OF A TRANSITORY RIDGING PATTERN...OR IN A NEAR ZONAL
PATTERN AHEAD OF THE NEXT APPROACHING AREA OF LOW PRESSURE.

&&

.AVIATION.../00Z ISSUANCE/

RELATIVELY QUIET PATTERN LEADS TO VFR CONDITIONS THROUGH 00Z SUNDAY.
LIGHT WINDS EXPECTED AT TAF SITES WITH SOME GUSTS 15 TO 20 KNOTS
OVER THE HIGHER TERRAIN FRIDAY NIGHT. SOME WEAK CONVECTION ACROSS
NORTHERN AND EASTERN WY WILL LINGER TO 03Z TO 06Z AS WELL. SATURDAY
WILL BE MOSTLY CLEAR WITH SIMILAR LIGHT WINDS AS FRIDAY. NEXT
STORMINESS EXPECTED OVER FAR SOUTHERN WY SATURDAY AFTERNOON AND THEN
INCREASING OVER SW WY MOUNTAINS SUNDAY AFTERNOON AND EVENING.

&&

.FIRE WEATHER...

GENERALLY QUIET WEATHER PATTERN THROUGH SUNDAY MORNING OVER THE
AREA WITH NEAR SEASONAL TEMPERATURES AND LOW RELATIVE HUMIDITY AT
THE SURFACE. AFTERNOON RH VALUES IN THE LOW TEENS AND UPPER SINGLE
DIGITS WILL CONTINUE INTO SATURDAY...WITH POOR OVERNIGHT RECOVERY
EXCEPT IN THE VALLEYS OF WESTERN WY. WINDS WILL REMAIN GENERALLY
LIGHT...EXCEPT FOR SOME ENHANCED NORTHEAST FLOW OVER SOUTHERN
WYOMING BOTH FRIDAY NIGHT AND SATURDAY NIGHT DUE TO SURFACE LOW
PRESSURE DEVELOPING OVER THE GREAT BASIN. SATURDAY LOOKS TO BE
MOSTLY CLEAR...WHILE SUNDAY SHOULD SEE INCREASING CLOUDINESS FROM
THE SOUTHWEST...WITH SHOWERS AND ISOLATED THUNDERSTORMS MOVING IN
SUNDAY EVENING. SUNDAY SHOULD SEE ABOVE NORMAL TEMPERATURES IN THE
MID 90S IN THE CENTRAL BASINS.

&&

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

&&

$$

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




000
FXUS65 KRIW 312340
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
540 PM MDT FRI JUL 31 2015

.SHORT TERM...TONIGHT THROUGH SATURDAY

THE UPPER LEVEL RIDGE IS OVER THE WESTERN US TODAY AND LOOKS TO
REMAIN FOR THE NEXT SEVEN DAYS. HOWEVER...THE DETAILS ARE A BIT
MESSY WITH EMBEDDED MOISTURE AND WEAK SHORT WAVE TROUGHS. FOR
TONIGHT AND SATURDAY...WYOMING WILL BE IN THE NW SECTOR OF THE
RIDGE. ISOLATED CONVECTIVE ACTIVITY LATE THIS AFTERNOON MAY
PERSIST INTO THE EVENING HOURS OVER THE ABSAROKAS AND
BIGHORNS...POTENTIALLY IMPACTING NORTHERN JOHNSON COUNTY. GUIDANCE
INDICATES THE BEST ACTION OVER EASTERN WYOMING AS SOME STORMS HAVE
ALREADY DEVELOPED AROUND CHEYENNE. AS SURFACE LOW PRESSURE
DEVELOPS OVER UTAH OVERNIGHT AND SURFACE HIGH PRESSURE MOVES INTO
MONTANA...LOW LEVEL WINDS ARE EXPECTED TO SHIFT TO THE
NORTHEAST...WITH SOME HIGHER GUSTS POSSIBLE IN SWEETWATER COUNTY.

LOW LEVEL DRYING IS EXPECTED FROM NORTH TO SOUTH ON
SATURDAY...KEEPING CONVECTIVE ACTIVITY TOMORROW WELL CAPPED. THE
ONLY AREA WITH A WEAK POTENTIAL IS AROUND SOUTHERN SWEETWATER
COUNTY WHERE WEAK INSTABILITY AND INCREASED MOISTURE MAY HELP A
COUPLE OF STORMS TO DEVELOP. OTHERWISE SIMILAR TEMPERATURES AND
WINDS ARE EXPECTED ON SATURDAY.

.LONG TERM...SATURDAY NIGHT THROUGH FRIDAY

CONTINUED HIGH PRESSURE WILL LEAVE DRY AND WARM CONDITIONS ACROSS
WESTERN AND CENTRAL WYOMING THROUGH SUNDAY MORNING. A WAVE OF LOW
PRESSURE WILL MOVE ACROSS THE DESERT SOUTHWEST SUNDAY
AFTERNOON...AND BEGIN TO MOVE INTO SOUTHERN WYOMING SUNDAY
AFTERNOON AND EVENING. THIS SYSTEM LOOKS TO HAVE DECENT POTENTIAL
TO INTRODUCE SHOWERS AND THUNDERSTORMS TO THE AREA AS IT MOVES
THROUGH. THE WAVE WILL BE SLOWER TO MOVE THROUGH THE AREA...
SPREADING SHOWER ACTIVITY AS IT MOVES THROUGH...ALONG WITH COOLER
TEMPERATURES. SHOWER AND THUNDERSTORM COVERAGE EXPECTED TO
INCREASE ACROSS MUCH OF THE STATE BY MONDAY AFTERNOON.

THE AXIS OF THE RIDGE OF HIGH PRESSURE WILL MOVE ACROSS MUCH OF
THE STATE BY TUESDAY MORNING...BRINGING A SOUTHWEST FLOW TO THE
AREA. ADDITIONAL PUSHES OF MOISTURE WILL THEN IMPACT THE AREA...KEEPING
AFTERNOON SHOWER AND THUNDERSTORM ACTIVITY PRESENT.

MODELS DIVERGE ON THEIR AGREEMENT WITH THE POTENTIAL FOR ANOTHER
WAVE OF LOW PRESSURE TO IMPACT THE AREA WEDNESDAY INTO THURSDAY.
THE GFS IS MORE AGGRESSIVE WITH ARRIVAL OF THIS SYSTEM PUSHING
THROUGH BY THURSDAY. THE ECMWF IS SLOWER WITH THE PROGRESS OF THIS
SYSTEM...HAVING IT MOVE THROUGH BY FRIDAY MORNING. DEPENDING ON
WHICH SOLUTION THEN IS ACCURATE... FRIDAY WILL EITHER BE UNDER THE
INFLUENCE OF A TRANSITORY RIDGING PATTERN...OR IN A NEAR ZONAL
PATTERN AHEAD OF THE NEXT APPROACHING AREA OF LOW PRESSURE.

&&

.AVIATION.../00Z ISSUANCE/

RELATIVELY QUIET PATTERN LEADS TO VFR CONDITIONS THROUGH 00Z SUNDAY.
LIGHT WINDS EXPECTED AT TAF SITES WITH SOME GUSTS 15 TO 20 KNOTS
OVER THE HIGHER TERRAIN FRIDAY NIGHT. SOME WEAK CONVECTION ACROSS
NORTHERN AND EASTERN WY WILL LINGER TO 03Z TO 06Z AS WELL. SATURDAY
WILL BE MOSTLY CLEAR WITH SIMILAR LIGHT WINDS AS FRIDAY. NEXT
STORMINESS EXPECTED OVER FAR SOUTHERN WY SATURDAY AFTERNOON AND THEN
INCREASING OVER SW WY MOUNTAINS SUNDAY AFTERNOON AND EVENING.

&&

.FIRE WEATHER...

GENERALLY QUIET WEATHER PATTERN THROUGH SUNDAY MORNING OVER THE
AREA WITH NEAR SEASONAL TEMPERATURES AND LOW RELATIVE HUMIDITY AT
THE SURFACE. AFTERNOON RH VALUES IN THE LOW TEENS AND UPPER SINGLE
DIGITS WILL CONTINUE INTO SATURDAY...WITH POOR OVERNIGHT RECOVERY
EXCEPT IN THE VALLEYS OF WESTERN WY. WINDS WILL REMAIN GENERALLY
LIGHT...EXCEPT FOR SOME ENHANCED NORTHEAST FLOW OVER SOUTHERN
WYOMING BOTH FRIDAY NIGHT AND SATURDAY NIGHT DUE TO SURFACE LOW
PRESSURE DEVELOPING OVER THE GREAT BASIN. SATURDAY LOOKS TO BE
MOSTLY CLEAR...WHILE SUNDAY SHOULD SEE INCREASING CLOUDINESS FROM
THE SOUTHWEST...WITH SHOWERS AND ISOLATED THUNDERSTORMS MOVING IN
SUNDAY EVENING. SUNDAY SHOULD SEE ABOVE NORMAL TEMPERATURES IN THE
MID 90S IN THE CENTRAL BASINS.

&&

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

&&

$$

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




000
FXUS65 KRIW 312340
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
540 PM MDT FRI JUL 31 2015

.SHORT TERM...TONIGHT THROUGH SATURDAY

THE UPPER LEVEL RIDGE IS OVER THE WESTERN US TODAY AND LOOKS TO
REMAIN FOR THE NEXT SEVEN DAYS. HOWEVER...THE DETAILS ARE A BIT
MESSY WITH EMBEDDED MOISTURE AND WEAK SHORT WAVE TROUGHS. FOR
TONIGHT AND SATURDAY...WYOMING WILL BE IN THE NW SECTOR OF THE
RIDGE. ISOLATED CONVECTIVE ACTIVITY LATE THIS AFTERNOON MAY
PERSIST INTO THE EVENING HOURS OVER THE ABSAROKAS AND
BIGHORNS...POTENTIALLY IMPACTING NORTHERN JOHNSON COUNTY. GUIDANCE
INDICATES THE BEST ACTION OVER EASTERN WYOMING AS SOME STORMS HAVE
ALREADY DEVELOPED AROUND CHEYENNE. AS SURFACE LOW PRESSURE
DEVELOPS OVER UTAH OVERNIGHT AND SURFACE HIGH PRESSURE MOVES INTO
MONTANA...LOW LEVEL WINDS ARE EXPECTED TO SHIFT TO THE
NORTHEAST...WITH SOME HIGHER GUSTS POSSIBLE IN SWEETWATER COUNTY.

LOW LEVEL DRYING IS EXPECTED FROM NORTH TO SOUTH ON
SATURDAY...KEEPING CONVECTIVE ACTIVITY TOMORROW WELL CAPPED. THE
ONLY AREA WITH A WEAK POTENTIAL IS AROUND SOUTHERN SWEETWATER
COUNTY WHERE WEAK INSTABILITY AND INCREASED MOISTURE MAY HELP A
COUPLE OF STORMS TO DEVELOP. OTHERWISE SIMILAR TEMPERATURES AND
WINDS ARE EXPECTED ON SATURDAY.

.LONG TERM...SATURDAY NIGHT THROUGH FRIDAY

CONTINUED HIGH PRESSURE WILL LEAVE DRY AND WARM CONDITIONS ACROSS
WESTERN AND CENTRAL WYOMING THROUGH SUNDAY MORNING. A WAVE OF LOW
PRESSURE WILL MOVE ACROSS THE DESERT SOUTHWEST SUNDAY
AFTERNOON...AND BEGIN TO MOVE INTO SOUTHERN WYOMING SUNDAY
AFTERNOON AND EVENING. THIS SYSTEM LOOKS TO HAVE DECENT POTENTIAL
TO INTRODUCE SHOWERS AND THUNDERSTORMS TO THE AREA AS IT MOVES
THROUGH. THE WAVE WILL BE SLOWER TO MOVE THROUGH THE AREA...
SPREADING SHOWER ACTIVITY AS IT MOVES THROUGH...ALONG WITH COOLER
TEMPERATURES. SHOWER AND THUNDERSTORM COVERAGE EXPECTED TO
INCREASE ACROSS MUCH OF THE STATE BY MONDAY AFTERNOON.

THE AXIS OF THE RIDGE OF HIGH PRESSURE WILL MOVE ACROSS MUCH OF
THE STATE BY TUESDAY MORNING...BRINGING A SOUTHWEST FLOW TO THE
AREA. ADDITIONAL PUSHES OF MOISTURE WILL THEN IMPACT THE AREA...KEEPING
AFTERNOON SHOWER AND THUNDERSTORM ACTIVITY PRESENT.

MODELS DIVERGE ON THEIR AGREEMENT WITH THE POTENTIAL FOR ANOTHER
WAVE OF LOW PRESSURE TO IMPACT THE AREA WEDNESDAY INTO THURSDAY.
THE GFS IS MORE AGGRESSIVE WITH ARRIVAL OF THIS SYSTEM PUSHING
THROUGH BY THURSDAY. THE ECMWF IS SLOWER WITH THE PROGRESS OF THIS
SYSTEM...HAVING IT MOVE THROUGH BY FRIDAY MORNING. DEPENDING ON
WHICH SOLUTION THEN IS ACCURATE... FRIDAY WILL EITHER BE UNDER THE
INFLUENCE OF A TRANSITORY RIDGING PATTERN...OR IN A NEAR ZONAL
PATTERN AHEAD OF THE NEXT APPROACHING AREA OF LOW PRESSURE.

&&

.AVIATION.../00Z ISSUANCE/

RELATIVELY QUIET PATTERN LEADS TO VFR CONDITIONS THROUGH 00Z SUNDAY.
LIGHT WINDS EXPECTED AT TAF SITES WITH SOME GUSTS 15 TO 20 KNOTS
OVER THE HIGHER TERRAIN FRIDAY NIGHT. SOME WEAK CONVECTION ACROSS
NORTHERN AND EASTERN WY WILL LINGER TO 03Z TO 06Z AS WELL. SATURDAY
WILL BE MOSTLY CLEAR WITH SIMILAR LIGHT WINDS AS FRIDAY. NEXT
STORMINESS EXPECTED OVER FAR SOUTHERN WY SATURDAY AFTERNOON AND THEN
INCREASING OVER SW WY MOUNTAINS SUNDAY AFTERNOON AND EVENING.

&&

.FIRE WEATHER...

GENERALLY QUIET WEATHER PATTERN THROUGH SUNDAY MORNING OVER THE
AREA WITH NEAR SEASONAL TEMPERATURES AND LOW RELATIVE HUMIDITY AT
THE SURFACE. AFTERNOON RH VALUES IN THE LOW TEENS AND UPPER SINGLE
DIGITS WILL CONTINUE INTO SATURDAY...WITH POOR OVERNIGHT RECOVERY
EXCEPT IN THE VALLEYS OF WESTERN WY. WINDS WILL REMAIN GENERALLY
LIGHT...EXCEPT FOR SOME ENHANCED NORTHEAST FLOW OVER SOUTHERN
WYOMING BOTH FRIDAY NIGHT AND SATURDAY NIGHT DUE TO SURFACE LOW
PRESSURE DEVELOPING OVER THE GREAT BASIN. SATURDAY LOOKS TO BE
MOSTLY CLEAR...WHILE SUNDAY SHOULD SEE INCREASING CLOUDINESS FROM
THE SOUTHWEST...WITH SHOWERS AND ISOLATED THUNDERSTORMS MOVING IN
SUNDAY EVENING. SUNDAY SHOULD SEE ABOVE NORMAL TEMPERATURES IN THE
MID 90S IN THE CENTRAL BASINS.

&&

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

&&

$$

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




000
FXUS65 KRIW 312340
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
540 PM MDT FRI JUL 31 2015

.SHORT TERM...TONIGHT THROUGH SATURDAY

THE UPPER LEVEL RIDGE IS OVER THE WESTERN US TODAY AND LOOKS TO
REMAIN FOR THE NEXT SEVEN DAYS. HOWEVER...THE DETAILS ARE A BIT
MESSY WITH EMBEDDED MOISTURE AND WEAK SHORT WAVE TROUGHS. FOR
TONIGHT AND SATURDAY...WYOMING WILL BE IN THE NW SECTOR OF THE
RIDGE. ISOLATED CONVECTIVE ACTIVITY LATE THIS AFTERNOON MAY
PERSIST INTO THE EVENING HOURS OVER THE ABSAROKAS AND
BIGHORNS...POTENTIALLY IMPACTING NORTHERN JOHNSON COUNTY. GUIDANCE
INDICATES THE BEST ACTION OVER EASTERN WYOMING AS SOME STORMS HAVE
ALREADY DEVELOPED AROUND CHEYENNE. AS SURFACE LOW PRESSURE
DEVELOPS OVER UTAH OVERNIGHT AND SURFACE HIGH PRESSURE MOVES INTO
MONTANA...LOW LEVEL WINDS ARE EXPECTED TO SHIFT TO THE
NORTHEAST...WITH SOME HIGHER GUSTS POSSIBLE IN SWEETWATER COUNTY.

LOW LEVEL DRYING IS EXPECTED FROM NORTH TO SOUTH ON
SATURDAY...KEEPING CONVECTIVE ACTIVITY TOMORROW WELL CAPPED. THE
ONLY AREA WITH A WEAK POTENTIAL IS AROUND SOUTHERN SWEETWATER
COUNTY WHERE WEAK INSTABILITY AND INCREASED MOISTURE MAY HELP A
COUPLE OF STORMS TO DEVELOP. OTHERWISE SIMILAR TEMPERATURES AND
WINDS ARE EXPECTED ON SATURDAY.

.LONG TERM...SATURDAY NIGHT THROUGH FRIDAY

CONTINUED HIGH PRESSURE WILL LEAVE DRY AND WARM CONDITIONS ACROSS
WESTERN AND CENTRAL WYOMING THROUGH SUNDAY MORNING. A WAVE OF LOW
PRESSURE WILL MOVE ACROSS THE DESERT SOUTHWEST SUNDAY
AFTERNOON...AND BEGIN TO MOVE INTO SOUTHERN WYOMING SUNDAY
AFTERNOON AND EVENING. THIS SYSTEM LOOKS TO HAVE DECENT POTENTIAL
TO INTRODUCE SHOWERS AND THUNDERSTORMS TO THE AREA AS IT MOVES
THROUGH. THE WAVE WILL BE SLOWER TO MOVE THROUGH THE AREA...
SPREADING SHOWER ACTIVITY AS IT MOVES THROUGH...ALONG WITH COOLER
TEMPERATURES. SHOWER AND THUNDERSTORM COVERAGE EXPECTED TO
INCREASE ACROSS MUCH OF THE STATE BY MONDAY AFTERNOON.

THE AXIS OF THE RIDGE OF HIGH PRESSURE WILL MOVE ACROSS MUCH OF
THE STATE BY TUESDAY MORNING...BRINGING A SOUTHWEST FLOW TO THE
AREA. ADDITIONAL PUSHES OF MOISTURE WILL THEN IMPACT THE AREA...KEEPING
AFTERNOON SHOWER AND THUNDERSTORM ACTIVITY PRESENT.

MODELS DIVERGE ON THEIR AGREEMENT WITH THE POTENTIAL FOR ANOTHER
WAVE OF LOW PRESSURE TO IMPACT THE AREA WEDNESDAY INTO THURSDAY.
THE GFS IS MORE AGGRESSIVE WITH ARRIVAL OF THIS SYSTEM PUSHING
THROUGH BY THURSDAY. THE ECMWF IS SLOWER WITH THE PROGRESS OF THIS
SYSTEM...HAVING IT MOVE THROUGH BY FRIDAY MORNING. DEPENDING ON
WHICH SOLUTION THEN IS ACCURATE... FRIDAY WILL EITHER BE UNDER THE
INFLUENCE OF A TRANSITORY RIDGING PATTERN...OR IN A NEAR ZONAL
PATTERN AHEAD OF THE NEXT APPROACHING AREA OF LOW PRESSURE.

&&

.AVIATION.../00Z ISSUANCE/

RELATIVELY QUIET PATTERN LEADS TO VFR CONDITIONS THROUGH 00Z SUNDAY.
LIGHT WINDS EXPECTED AT TAF SITES WITH SOME GUSTS 15 TO 20 KNOTS
OVER THE HIGHER TERRAIN FRIDAY NIGHT. SOME WEAK CONVECTION ACROSS
NORTHERN AND EASTERN WY WILL LINGER TO 03Z TO 06Z AS WELL. SATURDAY
WILL BE MOSTLY CLEAR WITH SIMILAR LIGHT WINDS AS FRIDAY. NEXT
STORMINESS EXPECTED OVER FAR SOUTHERN WY SATURDAY AFTERNOON AND THEN
INCREASING OVER SW WY MOUNTAINS SUNDAY AFTERNOON AND EVENING.

&&

.FIRE WEATHER...

GENERALLY QUIET WEATHER PATTERN THROUGH SUNDAY MORNING OVER THE
AREA WITH NEAR SEASONAL TEMPERATURES AND LOW RELATIVE HUMIDITY AT
THE SURFACE. AFTERNOON RH VALUES IN THE LOW TEENS AND UPPER SINGLE
DIGITS WILL CONTINUE INTO SATURDAY...WITH POOR OVERNIGHT RECOVERY
EXCEPT IN THE VALLEYS OF WESTERN WY. WINDS WILL REMAIN GENERALLY
LIGHT...EXCEPT FOR SOME ENHANCED NORTHEAST FLOW OVER SOUTHERN
WYOMING BOTH FRIDAY NIGHT AND SATURDAY NIGHT DUE TO SURFACE LOW
PRESSURE DEVELOPING OVER THE GREAT BASIN. SATURDAY LOOKS TO BE
MOSTLY CLEAR...WHILE SUNDAY SHOULD SEE INCREASING CLOUDINESS FROM
THE SOUTHWEST...WITH SHOWERS AND ISOLATED THUNDERSTORMS MOVING IN
SUNDAY EVENING. SUNDAY SHOULD SEE ABOVE NORMAL TEMPERATURES IN THE
MID 90S IN THE CENTRAL BASINS.

&&

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

&&

$$

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




000
FXUS63 KUNR 312333
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
533 PM MDT FRI JUL 31 2015

.SHORT TERM...THIS EVENING THROUGH SATURDAY NIGHT
ISSUED AT 204 PM MDT FRI JUL 31 2015

20Z ANALYSIS SHOWS SFC HIGH PRESSURE CENTERED OVER THE FORECAST
AREA WITH AN UPPER RIDGE BUILDING OVER THE WESTERN CONUS. MESO
ANALYSIS SHOWS MLCAPE CURRENTLY RANGING FROM 250-500J/KJ OVER
NORTHEASTERN WYOMING AND THE BLACK HILLS. SOME RELATIVELY FLAT CU
CURRENT NOTED OVER PARTS OF NERN WY AND THE BLKHLS. IF THE
CONVECTION MANAGES TO OVERCOME THE SYNOPTIC SCALE SUBSIDENCE OVER
THE REGION DURING THE REST OF THE AFTN...EXPECT ISOLATED SHORT
DURATION THUNDERSTORMS WHICH MAY RESULT IN GUSTY SFC WINDS.

A 25-30KT LL JET WILL DEVELOP OVER FAR WRN SD THIS EVENING
INCREASING THE MID-LEVEL THETA-E ADVECTION AND INCREASING THE
INSTABILITY ALOFT. MAY SEE ISOLATED ELEVATED THUNDERSTORMS
DEVELOP OVER FAR NERN WY/THE BLKHILLS THIS EVENING WHICH COULD
POSSIBLY CONTINUE THOUGH MUCH OF THE NIGHT IN THE ELEVATED
UNSTABLE LAYER...MOVING GRADUALLY SOUTHEAST OVERNIGHT. A WEAK
FRONTAL BOUNDARY WILL MOVE SOUTHWARD ACROSS THE FORECAST AREA ON
SATURDAY. DUE TO INSTABILITY AND LL FORCING ALONG AND NEAR THE
FRONT WILL INCLUDE A LOW CHANCE OF THUNDERSTORMS OVER SOUTHWESTERN
AND SOUTH CENTRAL SOUTH DAKOTA THROUGH THE DAY ON SATURDAY. HAVE
ALSO INCLUDED A SLIGHT CHANCE OF THUNDERSTORMS OVER THE CENTRAL
AND SOUTHERN BLACK HILLS ON SATURDAY AFTN AS CONVERGENCE ALONG
THE BOUNDARY COMBINED WITH DIURNAL HEATING MAY BE STRONG ENOUGH TO
OVERCOME THE SUBSIENCE BEHIND THE FRONT. HIGH TEMPERATURES ON THE
PLAINS ON SATURDAY ARE EXPECTED TO RANGE FROM THE UPPER 80S TO THE
UPPER 90S

.LONG TERM...SUNDAY THROUGH FRIDAY
ISSUED AT 204 PM MDT FRI JUL 31 2015

GFS/ECMWF STILL IN DECENT AGREEMENT WITH THE OVERALL
PATTERN FOR MUCH OF NEXT WEEK. HOWEVER...TIMING DIFFERENCES REMAIN
WITH IMPULSES MOVING THROUGH THE NORTHERN PLAINS...ESPECIALLY
FURTHER OUT IN TIME.

SUNDAY WILL BE WARM AND DRY AS UPPER RIDGE BUILDS ACROSS THE HIGH
PLAINS. HIGHS WILL BE IN THE 90S ON THE PLAINS WITH RELATIVE
HUMIDITY DROPPING TO AROUND 15 PERCENT AGAIN OVER NORTHEAST WY AND
FAR WESTERN SD. WINDS SHOULD STAY RELATIVELY LIGHT ACROSS THE AREA.

CHANCES FOR THUNDERSTORMS WILL BEGIN TO INCREASE EARLY IN THE
WEEK...STARTING LATE ON MONDAY...AS RIDGE WEAKENS ENOUGH TO ALLOW A
SERIES OF DISTURBANCES TO CROSS THE REGION. LOW LEVEL MOISTURE WILL
INCREASE AS EAST-SOUTHEAST WINDS BECOME RATHER PERSISTENT ACROSS THE
AREA THROUGH MIDWEEK...ESPECIALLY OVER AND EAST OF THE BLACK HILLS.
TIMING FOR BETTER CHANCES OF STORMS IS STILL UNCERTAIN AT THIS
POINT...BUT THE MIDDLE PART OF THE WEEK LOOKS TO BE THE MOST
FAVORABLE PERIOD. TEMPERATURES WILL BE NEAR AVERAGE THROUGH MUCH OF
THE WEEK.

&&

.AVIATION...FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING
ISSUED AT 529 PM MDT FRI JUL 31 2015

SCT CLDS OVR NERN WY AND BLK HLS WL DISSIPATE THIS EVENING. ISOLD TSTMS
MAY DVLP OVR SWRN SD TONITE AND MOV ACRS SCNTRL SD. LGT WNDS WL SHIFT
TO THE NW SAT MRNG BEHIND A COLD FRONT.

&&

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

$$

SHORT TERM...10
LONG TERM...26
AVIATION...55



000
FXUS63 KUNR 312333
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
533 PM MDT FRI JUL 31 2015

.SHORT TERM...THIS EVENING THROUGH SATURDAY NIGHT
ISSUED AT 204 PM MDT FRI JUL 31 2015

20Z ANALYSIS SHOWS SFC HIGH PRESSURE CENTERED OVER THE FORECAST
AREA WITH AN UPPER RIDGE BUILDING OVER THE WESTERN CONUS. MESO
ANALYSIS SHOWS MLCAPE CURRENTLY RANGING FROM 250-500J/KJ OVER
NORTHEASTERN WYOMING AND THE BLACK HILLS. SOME RELATIVELY FLAT CU
CURRENT NOTED OVER PARTS OF NERN WY AND THE BLKHLS. IF THE
CONVECTION MANAGES TO OVERCOME THE SYNOPTIC SCALE SUBSIDENCE OVER
THE REGION DURING THE REST OF THE AFTN...EXPECT ISOLATED SHORT
DURATION THUNDERSTORMS WHICH MAY RESULT IN GUSTY SFC WINDS.

A 25-30KT LL JET WILL DEVELOP OVER FAR WRN SD THIS EVENING
INCREASING THE MID-LEVEL THETA-E ADVECTION AND INCREASING THE
INSTABILITY ALOFT. MAY SEE ISOLATED ELEVATED THUNDERSTORMS
DEVELOP OVER FAR NERN WY/THE BLKHILLS THIS EVENING WHICH COULD
POSSIBLY CONTINUE THOUGH MUCH OF THE NIGHT IN THE ELEVATED
UNSTABLE LAYER...MOVING GRADUALLY SOUTHEAST OVERNIGHT. A WEAK
FRONTAL BOUNDARY WILL MOVE SOUTHWARD ACROSS THE FORECAST AREA ON
SATURDAY. DUE TO INSTABILITY AND LL FORCING ALONG AND NEAR THE
FRONT WILL INCLUDE A LOW CHANCE OF THUNDERSTORMS OVER SOUTHWESTERN
AND SOUTH CENTRAL SOUTH DAKOTA THROUGH THE DAY ON SATURDAY. HAVE
ALSO INCLUDED A SLIGHT CHANCE OF THUNDERSTORMS OVER THE CENTRAL
AND SOUTHERN BLACK HILLS ON SATURDAY AFTN AS CONVERGENCE ALONG
THE BOUNDARY COMBINED WITH DIURNAL HEATING MAY BE STRONG ENOUGH TO
OVERCOME THE SUBSIENCE BEHIND THE FRONT. HIGH TEMPERATURES ON THE
PLAINS ON SATURDAY ARE EXPECTED TO RANGE FROM THE UPPER 80S TO THE
UPPER 90S

.LONG TERM...SUNDAY THROUGH FRIDAY
ISSUED AT 204 PM MDT FRI JUL 31 2015

GFS/ECMWF STILL IN DECENT AGREEMENT WITH THE OVERALL
PATTERN FOR MUCH OF NEXT WEEK. HOWEVER...TIMING DIFFERENCES REMAIN
WITH IMPULSES MOVING THROUGH THE NORTHERN PLAINS...ESPECIALLY
FURTHER OUT IN TIME.

SUNDAY WILL BE WARM AND DRY AS UPPER RIDGE BUILDS ACROSS THE HIGH
PLAINS. HIGHS WILL BE IN THE 90S ON THE PLAINS WITH RELATIVE
HUMIDITY DROPPING TO AROUND 15 PERCENT AGAIN OVER NORTHEAST WY AND
FAR WESTERN SD. WINDS SHOULD STAY RELATIVELY LIGHT ACROSS THE AREA.

CHANCES FOR THUNDERSTORMS WILL BEGIN TO INCREASE EARLY IN THE
WEEK...STARTING LATE ON MONDAY...AS RIDGE WEAKENS ENOUGH TO ALLOW A
SERIES OF DISTURBANCES TO CROSS THE REGION. LOW LEVEL MOISTURE WILL
INCREASE AS EAST-SOUTHEAST WINDS BECOME RATHER PERSISTENT ACROSS THE
AREA THROUGH MIDWEEK...ESPECIALLY OVER AND EAST OF THE BLACK HILLS.
TIMING FOR BETTER CHANCES OF STORMS IS STILL UNCERTAIN AT THIS
POINT...BUT THE MIDDLE PART OF THE WEEK LOOKS TO BE THE MOST
FAVORABLE PERIOD. TEMPERATURES WILL BE NEAR AVERAGE THROUGH MUCH OF
THE WEEK.

&&

.AVIATION...FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING
ISSUED AT 529 PM MDT FRI JUL 31 2015

SCT CLDS OVR NERN WY AND BLK HLS WL DISSIPATE THIS EVENING. ISOLD TSTMS
MAY DVLP OVR SWRN SD TONITE AND MOV ACRS SCNTRL SD. LGT WNDS WL SHIFT
TO THE NW SAT MRNG BEHIND A COLD FRONT.

&&

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

$$

SHORT TERM...10
LONG TERM...26
AVIATION...55




000
FXUS63 KUNR 312333
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
533 PM MDT FRI JUL 31 2015

.SHORT TERM...THIS EVENING THROUGH SATURDAY NIGHT
ISSUED AT 204 PM MDT FRI JUL 31 2015

20Z ANALYSIS SHOWS SFC HIGH PRESSURE CENTERED OVER THE FORECAST
AREA WITH AN UPPER RIDGE BUILDING OVER THE WESTERN CONUS. MESO
ANALYSIS SHOWS MLCAPE CURRENTLY RANGING FROM 250-500J/KJ OVER
NORTHEASTERN WYOMING AND THE BLACK HILLS. SOME RELATIVELY FLAT CU
CURRENT NOTED OVER PARTS OF NERN WY AND THE BLKHLS. IF THE
CONVECTION MANAGES TO OVERCOME THE SYNOPTIC SCALE SUBSIDENCE OVER
THE REGION DURING THE REST OF THE AFTN...EXPECT ISOLATED SHORT
DURATION THUNDERSTORMS WHICH MAY RESULT IN GUSTY SFC WINDS.

A 25-30KT LL JET WILL DEVELOP OVER FAR WRN SD THIS EVENING
INCREASING THE MID-LEVEL THETA-E ADVECTION AND INCREASING THE
INSTABILITY ALOFT. MAY SEE ISOLATED ELEVATED THUNDERSTORMS
DEVELOP OVER FAR NERN WY/THE BLKHILLS THIS EVENING WHICH COULD
POSSIBLY CONTINUE THOUGH MUCH OF THE NIGHT IN THE ELEVATED
UNSTABLE LAYER...MOVING GRADUALLY SOUTHEAST OVERNIGHT. A WEAK
FRONTAL BOUNDARY WILL MOVE SOUTHWARD ACROSS THE FORECAST AREA ON
SATURDAY. DUE TO INSTABILITY AND LL FORCING ALONG AND NEAR THE
FRONT WILL INCLUDE A LOW CHANCE OF THUNDERSTORMS OVER SOUTHWESTERN
AND SOUTH CENTRAL SOUTH DAKOTA THROUGH THE DAY ON SATURDAY. HAVE
ALSO INCLUDED A SLIGHT CHANCE OF THUNDERSTORMS OVER THE CENTRAL
AND SOUTHERN BLACK HILLS ON SATURDAY AFTN AS CONVERGENCE ALONG
THE BOUNDARY COMBINED WITH DIURNAL HEATING MAY BE STRONG ENOUGH TO
OVERCOME THE SUBSIENCE BEHIND THE FRONT. HIGH TEMPERATURES ON THE
PLAINS ON SATURDAY ARE EXPECTED TO RANGE FROM THE UPPER 80S TO THE
UPPER 90S

.LONG TERM...SUNDAY THROUGH FRIDAY
ISSUED AT 204 PM MDT FRI JUL 31 2015

GFS/ECMWF STILL IN DECENT AGREEMENT WITH THE OVERALL
PATTERN FOR MUCH OF NEXT WEEK. HOWEVER...TIMING DIFFERENCES REMAIN
WITH IMPULSES MOVING THROUGH THE NORTHERN PLAINS...ESPECIALLY
FURTHER OUT IN TIME.

SUNDAY WILL BE WARM AND DRY AS UPPER RIDGE BUILDS ACROSS THE HIGH
PLAINS. HIGHS WILL BE IN THE 90S ON THE PLAINS WITH RELATIVE
HUMIDITY DROPPING TO AROUND 15 PERCENT AGAIN OVER NORTHEAST WY AND
FAR WESTERN SD. WINDS SHOULD STAY RELATIVELY LIGHT ACROSS THE AREA.

CHANCES FOR THUNDERSTORMS WILL BEGIN TO INCREASE EARLY IN THE
WEEK...STARTING LATE ON MONDAY...AS RIDGE WEAKENS ENOUGH TO ALLOW A
SERIES OF DISTURBANCES TO CROSS THE REGION. LOW LEVEL MOISTURE WILL
INCREASE AS EAST-SOUTHEAST WINDS BECOME RATHER PERSISTENT ACROSS THE
AREA THROUGH MIDWEEK...ESPECIALLY OVER AND EAST OF THE BLACK HILLS.
TIMING FOR BETTER CHANCES OF STORMS IS STILL UNCERTAIN AT THIS
POINT...BUT THE MIDDLE PART OF THE WEEK LOOKS TO BE THE MOST
FAVORABLE PERIOD. TEMPERATURES WILL BE NEAR AVERAGE THROUGH MUCH OF
THE WEEK.

&&

.AVIATION...FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING
ISSUED AT 529 PM MDT FRI JUL 31 2015

SCT CLDS OVR NERN WY AND BLK HLS WL DISSIPATE THIS EVENING. ISOLD TSTMS
MAY DVLP OVR SWRN SD TONITE AND MOV ACRS SCNTRL SD. LGT WNDS WL SHIFT
TO THE NW SAT MRNG BEHIND A COLD FRONT.

&&

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

$$

SHORT TERM...10
LONG TERM...26
AVIATION...55




000
FXUS65 KCYS 312118
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
318 PM MDT FRI JUL 31 2015

.SHORT TERM...(TODAY THRU SUNDAY NIGHT)

VIGOROUS SHOWERS AND THUNDERSTORMS DEVELOPED EARLY THIS AFTERNOON
ALONG THE SOUTHERN LARAMIE RANGE...PINE RIDGE...AND W-E ALONG A
CONVERGENCE BOUNDARY THAT FORMED JUST NORTH OF THE CHEYENNE RIDGE IN
NORTHERN LARAMIE COUNTY. MOIST SOUTHEASTERLY FLOW FED THIS
THUNDERSTORM ACTIVITY WITH SBCAPES INITIALLY IN THE 1000-2000 J/KG
RANGE ACROSS LARAMIE COUNTY AND ALONG THE PINE RIDGE. A FEW STRONGER
PULSE STORMS REMAIN ALONG THE PINE RIDGE AT THIS HOUR...WITH THE
WYOMING ACTIVITY DIMINISHING QUITE A BIT AFTER DROPPING A STRONG
COLD POOL AND PUSHING OUT A WELL DEFINED OUTFLOW BOUNDARY. CAN SEE
THE WESTERN EXTENT OF THIS BOUNDARY EXTENDING N-S ACROSS ALBANY
COUNTY WHICH MAY ALLOW FOR A FEW STORMS TO DEVELOP OUT IN THIS AREA
THROUGH THE LATE AFTERNOON AS WELL. WITH RELATIVELY MOIST LOW AND
MIDLEVELS IN PLACE...COULD SEE MODERATE RAIN AND SMALL HAIL WITH ANY
STRONGER STORMS THAT DEVELOP AS SBCAPES OUTSIDE OF THE COLD POOL ARE
STILL ROUGHLY 1000-2000 J/KG ACCORDING TO SPC MESOANALYSIS. FOR
TONIGHT...MOIST SOUTH-SOUTHEASTERLY SFC FLOW WILL CONTINUE AND THE
NOSE OF THE LLVL JET WILL PUSH UP INTO OUR FAR NORTHERN COUNTIES AND
INTO SOUTH DAKOTA. CANNOT RULE OUT A FEW SHOWERS/STORMS OVERNIGHT IN
THESE AREAS.

A WEAK SFC TROUGH STILL LOOKS TO SLIDE SOUTH ACROSS THE CWA TOMORROW
MORNING THRU THE EARLY AFTERNOON WITH AN ISOLATED STORM OR TWO
POSSIBLE ALONG THE FRONT AS IT ROLLS THROUGH. OTHERWISE...WINDS WILL
SHIFT TO THE NORTH AND WILL FILTER IN DRIER AIR FOR SATURDAY NIGHT
AND EARLY SUNDAY. A STRONGER UPPER LEVEL SYSTEM WILL APPROACH FROM
THE SOUTHWEST ON SUNDAY AFTERNOON AND EVENING...INDUCING PRESSURE
FALLS IN THE HIGH COUNTRY AND REINSTATING MOIST EAST-SOUTHEASTERLY
UPSLOPE FLOW TO THE PLAINS BY THE AFTERNOON. WITH INCREASING LIFT
AND MOISTURE ALOFT AND LLVL  MOIST ADVECTION ACROSS THE
PLAINS...EXPECT ANOTHER ROUND OF SHOWERS AND T-STORMS IN THE
AFTERNOON AND EVENING. THE FOCUS FOR CONVECTION LOOKS TO BE OVER THE
HIGHER PEAKS AND ALONG THE LARAMIE RANGE AND NEARBY EASTERN PLAINS.

.LONG TERM...(MONDAY THROUGH FRIDAY)
ISSUED AT 229 PM MDT FRI JUL 31 2015

LONG RANGE MODELS REMAIN IN POOR AGREEMENT FOR MOST OF NEXT
WEEK...ALTHOUGH OVERALL THERE IS MORE CONFIDENCE IN MONDAYS
FORECAST COMPARED TO 24 HOURS AGO. THE GFS IS IN DECENT AGREEMENT
WITH THE ECMWF AND GEM ON MONDAY...ALL SHOWING THE UPPER LEVEL
RIDGE AXIS BREAKING DOWN AND ALLOWING A VIGOROUS UPPER LEVEL
TROUGH TO PUSH FROM SOUTHWEST TO NORTHEAST ACROSS THE FORECAST
AREA MONDAY AFTERNOON. ALTHOUGH LLVL INSTABILITY APPEARS MARGINAL
AT THIS TIME...THE DISTURBANCE WILL PROVIDE JUST ENOUGH MID TO
UPPER LEVEL DYNAMICS TO TRIGGER AFTERNOON SHOWERS AND
THUNDERSTORMS OVER SOUTHEAST WYOMING AND EVENTUALLY THE HIGH
PLAINS OF WESTERN NEBRASKA THAT EVENING. INCREASED POP BETWEEN 25
TO 45 PERCENT ALONG AND WEST OF I25 WITH SLIGHTLY LOWER VALUES
FURTHER EAST.

THERE IS STILL QUITE A BIT OF UNCERTAINTY WITH NEXT WEEKS
FORECAST PAST MONDAY. NUMEROUS MODEL DIFFERENCES WITH THE TIMING
AND TRACK OF SHORTWAVE DISTURBANCES ALOFT ALONG WITH THE
CONSIDERABLE DIFFERENCES IN THE OVERALL PATTERN LATER IN THE WEEK
(THURSDAY AND FRIDAY) IS THE OVERALL FORECAST ISSUE IN THE LONG
TERM. THE TIMING OF THESE DISTURBANCES ARE KEY IN FORECASTING THE
COVERAGE OF POTENTIAL TSTORMS THIS TIME OF THE YEAR...SO THERE
REMAIN LOW CONFIDENCE IN THE LONG TERM. THE ECMWF IS NOW SHOWING
THE STRONG UPPER LEVEL RIDGE EXTENDING NORTHWARD INTO WYOMING FOR
THE MIDDLE TO LATE PART OF NEXT WEEK...AND NOW THE GFS SHOWS A
BACK DOOR COOL FRONT DIVING SOUTHWARD LATE WEDNESDAY AND INTO
THURSDAY. KEPT FORECAST SLIGHTLY ABOVE CLIMO FOR NOW...WITH 15 TO
20 PERCENT POP EACH DAY ACROSS THE HIGH PLAINS...AND HIGHS IN 80S
TO LOW 90S.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH SATURDAY MORNING)

CURRENT RADAR LOOP SHOWS CONVECTION DEVELOPING NEAR KCYS LATE THIS
MORNING...MAINLY ALONG THE SOUTHERN LARAMIE RANGE. THIS ACTIVITY
WILL GRADUALLY MOVE AND DEVELOP FURTHER EAST ALONG THE CHEYENNE
RIDGE TOWARDS KSNY THIS AFTERNOON. CONTINUED WITH VCTS FROM KLAR TO
KSNY INTO THIS EVENING...WHERE BRIEF MVFR VIS ARE POSSIBLE IN THE
HEAVIER SHOWERS. OTHERWISE...VFR CONDITIONS ARE EXPECTED THROUGH
TONIGHT.

&&

.FIRE WEATHER...
ISSUED AT 229 PM MDT FRI JUL 31 2015

ISOLATED TO WIDELY SCATTERED SHOWERS AND THUNDERSTORMS WILL CONTINUE
THROUGH THIS EVENING FOR LOCATIONS WITHIN AND EAST OF FWZ ZONES 307-
308. MUCH OF THIS ACTIVITY IS PRODUCING WETTING RAINFALL. DRY
CONDITIONS WILL RETURN TONIGHT...WITH MORE OF AN ISOLATED COVERAGE
OF SHOWERS AND STORMS POSSIBLE TOMORROW ALONG AND EAST OF THE
LARAMIE RANGE. VERY DRY HUMIDITIES WILL PERSIST THROUGH THE WEEKEND
FOR MUCH OF CARBON COUNTY...BUT WINDS STILL LOOK TO BE RELATIVELY
LIGHT.

&&

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

$$

SHORT TERM...RJM
LONG TERM...TJT
AVIATION...TJT
FIRE WEATHER...RJM



000
FXUS65 KCYS 312118
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
318 PM MDT FRI JUL 31 2015

.SHORT TERM...(TODAY THRU SUNDAY NIGHT)

VIGOROUS SHOWERS AND THUNDERSTORMS DEVELOPED EARLY THIS AFTERNOON
ALONG THE SOUTHERN LARAMIE RANGE...PINE RIDGE...AND W-E ALONG A
CONVERGENCE BOUNDARY THAT FORMED JUST NORTH OF THE CHEYENNE RIDGE IN
NORTHERN LARAMIE COUNTY. MOIST SOUTHEASTERLY FLOW FED THIS
THUNDERSTORM ACTIVITY WITH SBCAPES INITIALLY IN THE 1000-2000 J/KG
RANGE ACROSS LARAMIE COUNTY AND ALONG THE PINE RIDGE. A FEW STRONGER
PULSE STORMS REMAIN ALONG THE PINE RIDGE AT THIS HOUR...WITH THE
WYOMING ACTIVITY DIMINISHING QUITE A BIT AFTER DROPPING A STRONG
COLD POOL AND PUSHING OUT A WELL DEFINED OUTFLOW BOUNDARY. CAN SEE
THE WESTERN EXTENT OF THIS BOUNDARY EXTENDING N-S ACROSS ALBANY
COUNTY WHICH MAY ALLOW FOR A FEW STORMS TO DEVELOP OUT IN THIS AREA
THROUGH THE LATE AFTERNOON AS WELL. WITH RELATIVELY MOIST LOW AND
MIDLEVELS IN PLACE...COULD SEE MODERATE RAIN AND SMALL HAIL WITH ANY
STRONGER STORMS THAT DEVELOP AS SBCAPES OUTSIDE OF THE COLD POOL ARE
STILL ROUGHLY 1000-2000 J/KG ACCORDING TO SPC MESOANALYSIS. FOR
TONIGHT...MOIST SOUTH-SOUTHEASTERLY SFC FLOW WILL CONTINUE AND THE
NOSE OF THE LLVL JET WILL PUSH UP INTO OUR FAR NORTHERN COUNTIES AND
INTO SOUTH DAKOTA. CANNOT RULE OUT A FEW SHOWERS/STORMS OVERNIGHT IN
THESE AREAS.

A WEAK SFC TROUGH STILL LOOKS TO SLIDE SOUTH ACROSS THE CWA TOMORROW
MORNING THRU THE EARLY AFTERNOON WITH AN ISOLATED STORM OR TWO
POSSIBLE ALONG THE FRONT AS IT ROLLS THROUGH. OTHERWISE...WINDS WILL
SHIFT TO THE NORTH AND WILL FILTER IN DRIER AIR FOR SATURDAY NIGHT
AND EARLY SUNDAY. A STRONGER UPPER LEVEL SYSTEM WILL APPROACH FROM
THE SOUTHWEST ON SUNDAY AFTERNOON AND EVENING...INDUCING PRESSURE
FALLS IN THE HIGH COUNTRY AND REINSTATING MOIST EAST-SOUTHEASTERLY
UPSLOPE FLOW TO THE PLAINS BY THE AFTERNOON. WITH INCREASING LIFT
AND MOISTURE ALOFT AND LLVL  MOIST ADVECTION ACROSS THE
PLAINS...EXPECT ANOTHER ROUND OF SHOWERS AND T-STORMS IN THE
AFTERNOON AND EVENING. THE FOCUS FOR CONVECTION LOOKS TO BE OVER THE
HIGHER PEAKS AND ALONG THE LARAMIE RANGE AND NEARBY EASTERN PLAINS.

.LONG TERM...(MONDAY THROUGH FRIDAY)
ISSUED AT 229 PM MDT FRI JUL 31 2015

LONG RANGE MODELS REMAIN IN POOR AGREEMENT FOR MOST OF NEXT
WEEK...ALTHOUGH OVERALL THERE IS MORE CONFIDENCE IN MONDAYS
FORECAST COMPARED TO 24 HOURS AGO. THE GFS IS IN DECENT AGREEMENT
WITH THE ECMWF AND GEM ON MONDAY...ALL SHOWING THE UPPER LEVEL
RIDGE AXIS BREAKING DOWN AND ALLOWING A VIGOROUS UPPER LEVEL
TROUGH TO PUSH FROM SOUTHWEST TO NORTHEAST ACROSS THE FORECAST
AREA MONDAY AFTERNOON. ALTHOUGH LLVL INSTABILITY APPEARS MARGINAL
AT THIS TIME...THE DISTURBANCE WILL PROVIDE JUST ENOUGH MID TO
UPPER LEVEL DYNAMICS TO TRIGGER AFTERNOON SHOWERS AND
THUNDERSTORMS OVER SOUTHEAST WYOMING AND EVENTUALLY THE HIGH
PLAINS OF WESTERN NEBRASKA THAT EVENING. INCREASED POP BETWEEN 25
TO 45 PERCENT ALONG AND WEST OF I25 WITH SLIGHTLY LOWER VALUES
FURTHER EAST.

THERE IS STILL QUITE A BIT OF UNCERTAINTY WITH NEXT WEEKS
FORECAST PAST MONDAY. NUMEROUS MODEL DIFFERENCES WITH THE TIMING
AND TRACK OF SHORTWAVE DISTURBANCES ALOFT ALONG WITH THE
CONSIDERABLE DIFFERENCES IN THE OVERALL PATTERN LATER IN THE WEEK
(THURSDAY AND FRIDAY) IS THE OVERALL FORECAST ISSUE IN THE LONG
TERM. THE TIMING OF THESE DISTURBANCES ARE KEY IN FORECASTING THE
COVERAGE OF POTENTIAL TSTORMS THIS TIME OF THE YEAR...SO THERE
REMAIN LOW CONFIDENCE IN THE LONG TERM. THE ECMWF IS NOW SHOWING
THE STRONG UPPER LEVEL RIDGE EXTENDING NORTHWARD INTO WYOMING FOR
THE MIDDLE TO LATE PART OF NEXT WEEK...AND NOW THE GFS SHOWS A
BACK DOOR COOL FRONT DIVING SOUTHWARD LATE WEDNESDAY AND INTO
THURSDAY. KEPT FORECAST SLIGHTLY ABOVE CLIMO FOR NOW...WITH 15 TO
20 PERCENT POP EACH DAY ACROSS THE HIGH PLAINS...AND HIGHS IN 80S
TO LOW 90S.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH SATURDAY MORNING)

CURRENT RADAR LOOP SHOWS CONVECTION DEVELOPING NEAR KCYS LATE THIS
MORNING...MAINLY ALONG THE SOUTHERN LARAMIE RANGE. THIS ACTIVITY
WILL GRADUALLY MOVE AND DEVELOP FURTHER EAST ALONG THE CHEYENNE
RIDGE TOWARDS KSNY THIS AFTERNOON. CONTINUED WITH VCTS FROM KLAR TO
KSNY INTO THIS EVENING...WHERE BRIEF MVFR VIS ARE POSSIBLE IN THE
HEAVIER SHOWERS. OTHERWISE...VFR CONDITIONS ARE EXPECTED THROUGH
TONIGHT.

&&

.FIRE WEATHER...
ISSUED AT 229 PM MDT FRI JUL 31 2015

ISOLATED TO WIDELY SCATTERED SHOWERS AND THUNDERSTORMS WILL CONTINUE
THROUGH THIS EVENING FOR LOCATIONS WITHIN AND EAST OF FWZ ZONES 307-
308. MUCH OF THIS ACTIVITY IS PRODUCING WETTING RAINFALL. DRY
CONDITIONS WILL RETURN TONIGHT...WITH MORE OF AN ISOLATED COVERAGE
OF SHOWERS AND STORMS POSSIBLE TOMORROW ALONG AND EAST OF THE
LARAMIE RANGE. VERY DRY HUMIDITIES WILL PERSIST THROUGH THE WEEKEND
FOR MUCH OF CARBON COUNTY...BUT WINDS STILL LOOK TO BE RELATIVELY
LIGHT.

&&

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

$$

SHORT TERM...RJM
LONG TERM...TJT
AVIATION...TJT
FIRE WEATHER...RJM




000
FXUS63 KUNR 312024
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
224 PM MDT FRI JUL 31 2015

.SHORT TERM...THIS EVENING THROUGH SATURDAY NIGHT
ISSUED AT 204 PM MDT FRI JUL 31 2015

20Z ANALYSIS SHOWS SFC HIGH PRESSURE CENTERED OVER THE FORECAST
AREA WITH AN UPPER RIDGE BUILDING OVER THE WESTERN CONUS. MESO
ANALYSIS SHOWS MLCAPE CURRENTLY RANGING FROM 250-500J/KJ OVER
NORTHEASTERN WYOMING AND THE BLACK HILLS. SOME RELATIVELY FLAT CU
CURRENT NOTED OVER PARTS OF NERN WY AND THE BLKHLS. IF THE
CONVECTION MANAGES TO OVERCOME THE SYNOPTIC SCALE SUBSIDENCE OVER
THE REGION DURING THE REST OF THE AFTN...EXPECT ISOLATED SHORT
DURATION THUNDERSTORMS WHICH MAY RESULT IN GUSTY SFC WINDS.

A 25-30KT LL JET WILL DEVELOP OVER FAR WRN SD THIS EVENING
INCREASING THE MID-LEVEL THETA-E ADVECTION AND INCREASING THE
INSTABILITY ALOFT. MAY SEE ISOLATED ELEVATED THUNDERSTORMS
DEVELOP OVER FAR NERN WY/THE BLKHILLS THIS EVENING WHICH COULD
POSSIBLY CONTINUE THOUGH MUCH OF THE NIGHT IN THE ELEVATED
UNSTABLE LAYER...MOVING GRADUALLY SOUTHEAST OVERNIGHT. A WEAK
FRONTAL BOUNDARY WILL MOVE SOUTHWARD ACROSS THE FORECAST AREA ON
SATURDAY. DUE TO INSTABILITY AND LL FORCING ALONG AND NEAR THE
FRONT WILL INCLUDE A LOW CHANCE OF THUNDERSTORMS OVER SOUTHWESTERN
AND SOUTH CENTRAL SOUTH DAKOTA THROUGH THE DAY ON SATURDAY. HAVE
ALSO INCLUDED A SLIGHT CHANCE OF THUNDERSTORMS OVER THE CENTRAL
AND SOUTHERN BLACK HILLS ON SATURDAY AFTN AS CONVERGENCE ALONG
THE BOUNDARY COMBINED WITH DIURNAL HEATING MAY BE STRONG ENOUGH TO
OVERCOME THE SUBSIENCE BEHIND THE FRONT. HIGH TEMPERATURES ON THE
PLAINS ON SATURDAY ARE EXPECTED TO RANGE FROM THE UPPER 80S TO THE
UPPER 90S

.LONG TERM...SUNDAY THROUGH FRIDAY
ISSUED AT 204 PM MDT FRI JUL 31 2015

GFS/ECMWF STILL IN DECENT AGREEMENT WITH THE OVERALL
PATTERN FOR MUCH OF NEXT WEEK. HOWEVER...TIMING DIFFERENCES REMAIN
WITH IMPULSES MOVING THROUGH THE NORTHERN PLAINS...ESPECIALLY
FURTHER OUT IN TIME.

SUNDAY WILL BE WARM AND DRY AS UPPER RIDGE BUILDS ACROSS THE HIGH
PLAINS. HIGHS WILL BE IN THE 90S ON THE PLAINS WITH RELATIVE
HUMIDITY DROPPING TO AROUND 15 PERCENT AGAIN OVER NORTHEAST WY AND
FAR WESTERN SD. WINDS SHOULD STAY RELATIVELY LIGHT ACROSS THE AREA.

CHANCES FOR THUNDERSTORMS WILL BEGIN TO INCREASE EARLY IN THE
WEEK...STARTING LATE ON MONDAY...AS RIDGE WEAKENS ENOUGH TO ALLOW A
SERIES OF DISTURBANCES TO CROSS THE REGION. LOW LEVEL MOISTURE WILL
INCREASE AS EAST-SOUTHEAST WINDS BECOME RATHER PERSISTENT ACROSS THE
AREA THROUGH MIDWEEK...ESPECIALLY OVER AND EAST OF THE BLACK HILLS.
TIMING FOR BETTER CHANCES OF STORMS IS STILL UNCERTAIN AT THIS
POINT...BUT THE MIDDLE PART OF THE WEEK LOOKS TO BE THE MOST
FAVORABLE PERIOD. TEMPERATURES WILL BE NEAR AVERAGE THROUGH MUCH OF
THE WEEK.

&&

.AVIATION...FOR THE 18Z TAFS THROUGH 18Z SATURDAY
ISSUED AT 204 PM MDT FRI JUL 31 2015

VFR CONDITIONS ARE GENERALLY EXPECTED THROUGH TONIGHT.
ISOLATED SHOWERS AND THUNDERSTORMS ARE POSSIBLE LATE THIS AFTERNOON
AND ESPECIALLY TONIGHT FROM PORTIONS OF NORTHEAST WY...THROUGH THE
BLACK HILLS...AND ACROSS SOUTHERN SD.

&&

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

$$

SHORT TERM...10
LONG TERM...26
AVIATION...26



000
FXUS63 KUNR 312024
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
224 PM MDT FRI JUL 31 2015

.SHORT TERM...THIS EVENING THROUGH SATURDAY NIGHT
ISSUED AT 204 PM MDT FRI JUL 31 2015

20Z ANALYSIS SHOWS SFC HIGH PRESSURE CENTERED OVER THE FORECAST
AREA WITH AN UPPER RIDGE BUILDING OVER THE WESTERN CONUS. MESO
ANALYSIS SHOWS MLCAPE CURRENTLY RANGING FROM 250-500J/KJ OVER
NORTHEASTERN WYOMING AND THE BLACK HILLS. SOME RELATIVELY FLAT CU
CURRENT NOTED OVER PARTS OF NERN WY AND THE BLKHLS. IF THE
CONVECTION MANAGES TO OVERCOME THE SYNOPTIC SCALE SUBSIDENCE OVER
THE REGION DURING THE REST OF THE AFTN...EXPECT ISOLATED SHORT
DURATION THUNDERSTORMS WHICH MAY RESULT IN GUSTY SFC WINDS.

A 25-30KT LL JET WILL DEVELOP OVER FAR WRN SD THIS EVENING
INCREASING THE MID-LEVEL THETA-E ADVECTION AND INCREASING THE
INSTABILITY ALOFT. MAY SEE ISOLATED ELEVATED THUNDERSTORMS
DEVELOP OVER FAR NERN WY/THE BLKHILLS THIS EVENING WHICH COULD
POSSIBLY CONTINUE THOUGH MUCH OF THE NIGHT IN THE ELEVATED
UNSTABLE LAYER...MOVING GRADUALLY SOUTHEAST OVERNIGHT. A WEAK
FRONTAL BOUNDARY WILL MOVE SOUTHWARD ACROSS THE FORECAST AREA ON
SATURDAY. DUE TO INSTABILITY AND LL FORCING ALONG AND NEAR THE
FRONT WILL INCLUDE A LOW CHANCE OF THUNDERSTORMS OVER SOUTHWESTERN
AND SOUTH CENTRAL SOUTH DAKOTA THROUGH THE DAY ON SATURDAY. HAVE
ALSO INCLUDED A SLIGHT CHANCE OF THUNDERSTORMS OVER THE CENTRAL
AND SOUTHERN BLACK HILLS ON SATURDAY AFTN AS CONVERGENCE ALONG
THE BOUNDARY COMBINED WITH DIURNAL HEATING MAY BE STRONG ENOUGH TO
OVERCOME THE SUBSIENCE BEHIND THE FRONT. HIGH TEMPERATURES ON THE
PLAINS ON SATURDAY ARE EXPECTED TO RANGE FROM THE UPPER 80S TO THE
UPPER 90S

.LONG TERM...SUNDAY THROUGH FRIDAY
ISSUED AT 204 PM MDT FRI JUL 31 2015

GFS/ECMWF STILL IN DECENT AGREEMENT WITH THE OVERALL
PATTERN FOR MUCH OF NEXT WEEK. HOWEVER...TIMING DIFFERENCES REMAIN
WITH IMPULSES MOVING THROUGH THE NORTHERN PLAINS...ESPECIALLY
FURTHER OUT IN TIME.

SUNDAY WILL BE WARM AND DRY AS UPPER RIDGE BUILDS ACROSS THE HIGH
PLAINS. HIGHS WILL BE IN THE 90S ON THE PLAINS WITH RELATIVE
HUMIDITY DROPPING TO AROUND 15 PERCENT AGAIN OVER NORTHEAST WY AND
FAR WESTERN SD. WINDS SHOULD STAY RELATIVELY LIGHT ACROSS THE AREA.

CHANCES FOR THUNDERSTORMS WILL BEGIN TO INCREASE EARLY IN THE
WEEK...STARTING LATE ON MONDAY...AS RIDGE WEAKENS ENOUGH TO ALLOW A
SERIES OF DISTURBANCES TO CROSS THE REGION. LOW LEVEL MOISTURE WILL
INCREASE AS EAST-SOUTHEAST WINDS BECOME RATHER PERSISTENT ACROSS THE
AREA THROUGH MIDWEEK...ESPECIALLY OVER AND EAST OF THE BLACK HILLS.
TIMING FOR BETTER CHANCES OF STORMS IS STILL UNCERTAIN AT THIS
POINT...BUT THE MIDDLE PART OF THE WEEK LOOKS TO BE THE MOST
FAVORABLE PERIOD. TEMPERATURES WILL BE NEAR AVERAGE THROUGH MUCH OF
THE WEEK.

&&

.AVIATION...FOR THE 18Z TAFS THROUGH 18Z SATURDAY
ISSUED AT 204 PM MDT FRI JUL 31 2015

VFR CONDITIONS ARE GENERALLY EXPECTED THROUGH TONIGHT.
ISOLATED SHOWERS AND THUNDERSTORMS ARE POSSIBLE LATE THIS AFTERNOON
AND ESPECIALLY TONIGHT FROM PORTIONS OF NORTHEAST WY...THROUGH THE
BLACK HILLS...AND ACROSS SOUTHERN SD.

&&

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

$$

SHORT TERM...10
LONG TERM...26
AVIATION...26



000
FXUS63 KUNR 312024
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
224 PM MDT FRI JUL 31 2015

.SHORT TERM...THIS EVENING THROUGH SATURDAY NIGHT
ISSUED AT 204 PM MDT FRI JUL 31 2015

20Z ANALYSIS SHOWS SFC HIGH PRESSURE CENTERED OVER THE FORECAST
AREA WITH AN UPPER RIDGE BUILDING OVER THE WESTERN CONUS. MESO
ANALYSIS SHOWS MLCAPE CURRENTLY RANGING FROM 250-500J/KJ OVER
NORTHEASTERN WYOMING AND THE BLACK HILLS. SOME RELATIVELY FLAT CU
CURRENT NOTED OVER PARTS OF NERN WY AND THE BLKHLS. IF THE
CONVECTION MANAGES TO OVERCOME THE SYNOPTIC SCALE SUBSIDENCE OVER
THE REGION DURING THE REST OF THE AFTN...EXPECT ISOLATED SHORT
DURATION THUNDERSTORMS WHICH MAY RESULT IN GUSTY SFC WINDS.

A 25-30KT LL JET WILL DEVELOP OVER FAR WRN SD THIS EVENING
INCREASING THE MID-LEVEL THETA-E ADVECTION AND INCREASING THE
INSTABILITY ALOFT. MAY SEE ISOLATED ELEVATED THUNDERSTORMS
DEVELOP OVER FAR NERN WY/THE BLKHILLS THIS EVENING WHICH COULD
POSSIBLY CONTINUE THOUGH MUCH OF THE NIGHT IN THE ELEVATED
UNSTABLE LAYER...MOVING GRADUALLY SOUTHEAST OVERNIGHT. A WEAK
FRONTAL BOUNDARY WILL MOVE SOUTHWARD ACROSS THE FORECAST AREA ON
SATURDAY. DUE TO INSTABILITY AND LL FORCING ALONG AND NEAR THE
FRONT WILL INCLUDE A LOW CHANCE OF THUNDERSTORMS OVER SOUTHWESTERN
AND SOUTH CENTRAL SOUTH DAKOTA THROUGH THE DAY ON SATURDAY. HAVE
ALSO INCLUDED A SLIGHT CHANCE OF THUNDERSTORMS OVER THE CENTRAL
AND SOUTHERN BLACK HILLS ON SATURDAY AFTN AS CONVERGENCE ALONG
THE BOUNDARY COMBINED WITH DIURNAL HEATING MAY BE STRONG ENOUGH TO
OVERCOME THE SUBSIENCE BEHIND THE FRONT. HIGH TEMPERATURES ON THE
PLAINS ON SATURDAY ARE EXPECTED TO RANGE FROM THE UPPER 80S TO THE
UPPER 90S

.LONG TERM...SUNDAY THROUGH FRIDAY
ISSUED AT 204 PM MDT FRI JUL 31 2015

GFS/ECMWF STILL IN DECENT AGREEMENT WITH THE OVERALL
PATTERN FOR MUCH OF NEXT WEEK. HOWEVER...TIMING DIFFERENCES REMAIN
WITH IMPULSES MOVING THROUGH THE NORTHERN PLAINS...ESPECIALLY
FURTHER OUT IN TIME.

SUNDAY WILL BE WARM AND DRY AS UPPER RIDGE BUILDS ACROSS THE HIGH
PLAINS. HIGHS WILL BE IN THE 90S ON THE PLAINS WITH RELATIVE
HUMIDITY DROPPING TO AROUND 15 PERCENT AGAIN OVER NORTHEAST WY AND
FAR WESTERN SD. WINDS SHOULD STAY RELATIVELY LIGHT ACROSS THE AREA.

CHANCES FOR THUNDERSTORMS WILL BEGIN TO INCREASE EARLY IN THE
WEEK...STARTING LATE ON MONDAY...AS RIDGE WEAKENS ENOUGH TO ALLOW A
SERIES OF DISTURBANCES TO CROSS THE REGION. LOW LEVEL MOISTURE WILL
INCREASE AS EAST-SOUTHEAST WINDS BECOME RATHER PERSISTENT ACROSS THE
AREA THROUGH MIDWEEK...ESPECIALLY OVER AND EAST OF THE BLACK HILLS.
TIMING FOR BETTER CHANCES OF STORMS IS STILL UNCERTAIN AT THIS
POINT...BUT THE MIDDLE PART OF THE WEEK LOOKS TO BE THE MOST
FAVORABLE PERIOD. TEMPERATURES WILL BE NEAR AVERAGE THROUGH MUCH OF
THE WEEK.

&&

.AVIATION...FOR THE 18Z TAFS THROUGH 18Z SATURDAY
ISSUED AT 204 PM MDT FRI JUL 31 2015

VFR CONDITIONS ARE GENERALLY EXPECTED THROUGH TONIGHT.
ISOLATED SHOWERS AND THUNDERSTORMS ARE POSSIBLE LATE THIS AFTERNOON
AND ESPECIALLY TONIGHT FROM PORTIONS OF NORTHEAST WY...THROUGH THE
BLACK HILLS...AND ACROSS SOUTHERN SD.

&&

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

$$

SHORT TERM...10
LONG TERM...26
AVIATION...26



000
FXUS63 KUNR 312024
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
224 PM MDT FRI JUL 31 2015

.SHORT TERM...THIS EVENING THROUGH SATURDAY NIGHT
ISSUED AT 204 PM MDT FRI JUL 31 2015

20Z ANALYSIS SHOWS SFC HIGH PRESSURE CENTERED OVER THE FORECAST
AREA WITH AN UPPER RIDGE BUILDING OVER THE WESTERN CONUS. MESO
ANALYSIS SHOWS MLCAPE CURRENTLY RANGING FROM 250-500J/KJ OVER
NORTHEASTERN WYOMING AND THE BLACK HILLS. SOME RELATIVELY FLAT CU
CURRENT NOTED OVER PARTS OF NERN WY AND THE BLKHLS. IF THE
CONVECTION MANAGES TO OVERCOME THE SYNOPTIC SCALE SUBSIDENCE OVER
THE REGION DURING THE REST OF THE AFTN...EXPECT ISOLATED SHORT
DURATION THUNDERSTORMS WHICH MAY RESULT IN GUSTY SFC WINDS.

A 25-30KT LL JET WILL DEVELOP OVER FAR WRN SD THIS EVENING
INCREASING THE MID-LEVEL THETA-E ADVECTION AND INCREASING THE
INSTABILITY ALOFT. MAY SEE ISOLATED ELEVATED THUNDERSTORMS
DEVELOP OVER FAR NERN WY/THE BLKHILLS THIS EVENING WHICH COULD
POSSIBLY CONTINUE THOUGH MUCH OF THE NIGHT IN THE ELEVATED
UNSTABLE LAYER...MOVING GRADUALLY SOUTHEAST OVERNIGHT. A WEAK
FRONTAL BOUNDARY WILL MOVE SOUTHWARD ACROSS THE FORECAST AREA ON
SATURDAY. DUE TO INSTABILITY AND LL FORCING ALONG AND NEAR THE
FRONT WILL INCLUDE A LOW CHANCE OF THUNDERSTORMS OVER SOUTHWESTERN
AND SOUTH CENTRAL SOUTH DAKOTA THROUGH THE DAY ON SATURDAY. HAVE
ALSO INCLUDED A SLIGHT CHANCE OF THUNDERSTORMS OVER THE CENTRAL
AND SOUTHERN BLACK HILLS ON SATURDAY AFTN AS CONVERGENCE ALONG
THE BOUNDARY COMBINED WITH DIURNAL HEATING MAY BE STRONG ENOUGH TO
OVERCOME THE SUBSIENCE BEHIND THE FRONT. HIGH TEMPERATURES ON THE
PLAINS ON SATURDAY ARE EXPECTED TO RANGE FROM THE UPPER 80S TO THE
UPPER 90S

.LONG TERM...SUNDAY THROUGH FRIDAY
ISSUED AT 204 PM MDT FRI JUL 31 2015

GFS/ECMWF STILL IN DECENT AGREEMENT WITH THE OVERALL
PATTERN FOR MUCH OF NEXT WEEK. HOWEVER...TIMING DIFFERENCES REMAIN
WITH IMPULSES MOVING THROUGH THE NORTHERN PLAINS...ESPECIALLY
FURTHER OUT IN TIME.

SUNDAY WILL BE WARM AND DRY AS UPPER RIDGE BUILDS ACROSS THE HIGH
PLAINS. HIGHS WILL BE IN THE 90S ON THE PLAINS WITH RELATIVE
HUMIDITY DROPPING TO AROUND 15 PERCENT AGAIN OVER NORTHEAST WY AND
FAR WESTERN SD. WINDS SHOULD STAY RELATIVELY LIGHT ACROSS THE AREA.

CHANCES FOR THUNDERSTORMS WILL BEGIN TO INCREASE EARLY IN THE
WEEK...STARTING LATE ON MONDAY...AS RIDGE WEAKENS ENOUGH TO ALLOW A
SERIES OF DISTURBANCES TO CROSS THE REGION. LOW LEVEL MOISTURE WILL
INCREASE AS EAST-SOUTHEAST WINDS BECOME RATHER PERSISTENT ACROSS THE
AREA THROUGH MIDWEEK...ESPECIALLY OVER AND EAST OF THE BLACK HILLS.
TIMING FOR BETTER CHANCES OF STORMS IS STILL UNCERTAIN AT THIS
POINT...BUT THE MIDDLE PART OF THE WEEK LOOKS TO BE THE MOST
FAVORABLE PERIOD. TEMPERATURES WILL BE NEAR AVERAGE THROUGH MUCH OF
THE WEEK.

&&

.AVIATION...FOR THE 18Z TAFS THROUGH 18Z SATURDAY
ISSUED AT 204 PM MDT FRI JUL 31 2015

VFR CONDITIONS ARE GENERALLY EXPECTED THROUGH TONIGHT.
ISOLATED SHOWERS AND THUNDERSTORMS ARE POSSIBLE LATE THIS AFTERNOON
AND ESPECIALLY TONIGHT FROM PORTIONS OF NORTHEAST WY...THROUGH THE
BLACK HILLS...AND ACROSS SOUTHERN SD.

&&

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

$$

SHORT TERM...10
LONG TERM...26
AVIATION...26



000
FXUS63 KUNR 312024
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
224 PM MDT FRI JUL 31 2015

.SHORT TERM...THIS EVENING THROUGH SATURDAY NIGHT
ISSUED AT 204 PM MDT FRI JUL 31 2015

20Z ANALYSIS SHOWS SFC HIGH PRESSURE CENTERED OVER THE FORECAST
AREA WITH AN UPPER RIDGE BUILDING OVER THE WESTERN CONUS. MESO
ANALYSIS SHOWS MLCAPE CURRENTLY RANGING FROM 250-500J/KJ OVER
NORTHEASTERN WYOMING AND THE BLACK HILLS. SOME RELATIVELY FLAT CU
CURRENT NOTED OVER PARTS OF NERN WY AND THE BLKHLS. IF THE
CONVECTION MANAGES TO OVERCOME THE SYNOPTIC SCALE SUBSIDENCE OVER
THE REGION DURING THE REST OF THE AFTN...EXPECT ISOLATED SHORT
DURATION THUNDERSTORMS WHICH MAY RESULT IN GUSTY SFC WINDS.

A 25-30KT LL JET WILL DEVELOP OVER FAR WRN SD THIS EVENING
INCREASING THE MID-LEVEL THETA-E ADVECTION AND INCREASING THE
INSTABILITY ALOFT. MAY SEE ISOLATED ELEVATED THUNDERSTORMS
DEVELOP OVER FAR NERN WY/THE BLKHILLS THIS EVENING WHICH COULD
POSSIBLY CONTINUE THOUGH MUCH OF THE NIGHT IN THE ELEVATED
UNSTABLE LAYER...MOVING GRADUALLY SOUTHEAST OVERNIGHT. A WEAK
FRONTAL BOUNDARY WILL MOVE SOUTHWARD ACROSS THE FORECAST AREA ON
SATURDAY. DUE TO INSTABILITY AND LL FORCING ALONG AND NEAR THE
FRONT WILL INCLUDE A LOW CHANCE OF THUNDERSTORMS OVER SOUTHWESTERN
AND SOUTH CENTRAL SOUTH DAKOTA THROUGH THE DAY ON SATURDAY. HAVE
ALSO INCLUDED A SLIGHT CHANCE OF THUNDERSTORMS OVER THE CENTRAL
AND SOUTHERN BLACK HILLS ON SATURDAY AFTN AS CONVERGENCE ALONG
THE BOUNDARY COMBINED WITH DIURNAL HEATING MAY BE STRONG ENOUGH TO
OVERCOME THE SUBSIENCE BEHIND THE FRONT. HIGH TEMPERATURES ON THE
PLAINS ON SATURDAY ARE EXPECTED TO RANGE FROM THE UPPER 80S TO THE
UPPER 90S

.LONG TERM...SUNDAY THROUGH FRIDAY
ISSUED AT 204 PM MDT FRI JUL 31 2015

GFS/ECMWF STILL IN DECENT AGREEMENT WITH THE OVERALL
PATTERN FOR MUCH OF NEXT WEEK. HOWEVER...TIMING DIFFERENCES REMAIN
WITH IMPULSES MOVING THROUGH THE NORTHERN PLAINS...ESPECIALLY
FURTHER OUT IN TIME.

SUNDAY WILL BE WARM AND DRY AS UPPER RIDGE BUILDS ACROSS THE HIGH
PLAINS. HIGHS WILL BE IN THE 90S ON THE PLAINS WITH RELATIVE
HUMIDITY DROPPING TO AROUND 15 PERCENT AGAIN OVER NORTHEAST WY AND
FAR WESTERN SD. WINDS SHOULD STAY RELATIVELY LIGHT ACROSS THE AREA.

CHANCES FOR THUNDERSTORMS WILL BEGIN TO INCREASE EARLY IN THE
WEEK...STARTING LATE ON MONDAY...AS RIDGE WEAKENS ENOUGH TO ALLOW A
SERIES OF DISTURBANCES TO CROSS THE REGION. LOW LEVEL MOISTURE WILL
INCREASE AS EAST-SOUTHEAST WINDS BECOME RATHER PERSISTENT ACROSS THE
AREA THROUGH MIDWEEK...ESPECIALLY OVER AND EAST OF THE BLACK HILLS.
TIMING FOR BETTER CHANCES OF STORMS IS STILL UNCERTAIN AT THIS
POINT...BUT THE MIDDLE PART OF THE WEEK LOOKS TO BE THE MOST
FAVORABLE PERIOD. TEMPERATURES WILL BE NEAR AVERAGE THROUGH MUCH OF
THE WEEK.

&&

.AVIATION...FOR THE 18Z TAFS THROUGH 18Z SATURDAY
ISSUED AT 204 PM MDT FRI JUL 31 2015

VFR CONDITIONS ARE GENERALLY EXPECTED THROUGH TONIGHT.
ISOLATED SHOWERS AND THUNDERSTORMS ARE POSSIBLE LATE THIS AFTERNOON
AND ESPECIALLY TONIGHT FROM PORTIONS OF NORTHEAST WY...THROUGH THE
BLACK HILLS...AND ACROSS SOUTHERN SD.

&&

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

$$

SHORT TERM...10
LONG TERM...26
AVIATION...26



000
FXUS65 KRIW 312015
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
215 PM MDT FRI JUL 31 2015

.SHORT TERM...TONIGHT THROUGH SATURDAY

THE UPPER LEVEL RIDGE IS OVER THE WESTERN US TODAY AND LOOKS TO
REMAIN FOR THE NEXT SEVEN DAYS. HOWEVER...THE DETAILS ARE A BIT
MESSY WITH EMBEDDED MOISTURE AND WEAK SHORT WAVE TROUGHS. FOR
TONIGHT AND SATURDAY...WYOMING WILL BE IN THE NW SECTOR OF THE
RIDGE. ISOLATED CONVECTIVE ACTIVITY LATE THIS AFTERNOON MAY
PERSIST INTO THE EVENING HOURS OVER THE ABSAROKAS AND
BIGHORNS...POTENTIALLY IMPACTING NORTHERN JOHNSON COUNTY. GUIDANCE
INDICATES THE BEST ACTION OVER EASTERN WYOMING AS SOME STORMS HAVE
ALREADY DEVELOPED AROUND CHEYENNE. AS SURFACE LOW PRESSURE
DEVELOPS OVER UTAH OVERNIGHT AND SURFACE HIGH PRESSURE MOVES INTO
MONTANA...LOW LEVEL WINDS ARE EXPECTED TO SHIFT TO THE
NORTHEAST...WITH SOME HIGHER GUSTS POSSIBLE IN SWEETWATER COUNTY.

LOW LEVEL DRYING IS EXPECTED FROM NORTH TO SOUTH ON
SATURDAY...KEEPING CONVECTIVE ACTIVITY TOMORROW WELL CAPPED. THE
ONLY AREA WITH A WEAK POTENTIAL IS AROUND SOUTHERN SWEETWATER
COUNTY WHERE WEAK INSTABILITY AND INCREASED MOISTURE MAY HELP A
COUPLE OF STORMS TO DEVELOP. OTHERWISE SIMILAR TEMPERATURES AND
WINDS ARE EXPECTED ON SATURDAY.

.LONG TERM...SATURDAY NIGHT THROUGH FRIDAY

CONTINUED HIGH PRESSURE WILL LEAVE DRY AND WARM CONDITIONS ACROSS
WESTERN AND CENTRAL WYOMING THROUGH SUNDAY MORNING. A WAVE OF LOW
PRESSURE WILL MOVE ACROSS THE DESERT SOUTHWEST SUNDAY
AFTERNOON...AND BEGIN TO MOVE INTO SOUTHERN WYOMING SUNDAY
AFTERNOON AND EVENING. THIS SYSTEM LOOKS TO HAVE DECENT POTENTIAL
TO INTRODUCE SHOWERS AND THUNDERSTORMS TO THE AREA AS IT MOVES
THROUGH. THE WAVE WILL BE SLOWER TO MOVE THROUGH THE AREA...
SPREADING SHOWER ACTIVITY AS IT MOVES THROUGH...ALONG WITH COOLER
TEMPERATURES. SHOWER AND THUNDERSTORM COVERAGE EXPECTED TO
INCREASE ACROSS MUCH OF THE STATE BY MONDAY AFTERNOON.

THE AXIS OF THE RIDGE OF HIGH PRESSURE WILL MOVE ACROSS MUCH OF
THE STATE BY TUESDAY MORNING...BRINGING A SOUTHWEST FLOW TO THE
AREA. ADDITIONAL PUSHES OF MOISTURE WILL THEN IMPACT THE AREA...KEEPING
AFTERNOON SHOWER AND THUNDERSTORM ACTIVITY PRESENT.

MODELS DIVERGE ON THEIR AGREEMENT WITH THE POTENTIAL FOR ANOTHER
WAVE OF LOW PRESSURE TO IMPACT THE AREA WEDNESDAY INTO THURSDAY.
THE GFS IS MORE AGGRESSIVE WITH ARRIVAL OF THIS SYSTEM PUSHING
THROUGH BY THURSDAY. THE ECMWF IS SLOWER WITH THE PROGRESS OF THIS
SYSTEM...HAVING IT MOVE THROUGH BY FRIDAY MORNING. DEPENDING ON
WHICH SOLUTION THEN IS ACCURATE... FRIDAY WILL EITHER BE UNDER THE
INFLUENCE OF A TRANSITORY RIDGING PATTERN...OR IN A NEAR ZONAL
PATTERN AHEAD OF THE NEXT APPROACHING AREA OF LOW PRESSURE.

&&

.AVIATION.../18Z ISSUANCE/

VFR CONDITIONS STILL EXPECTED THROUGH 00Z SUNDAY WITH RELATIVELY
QUIET WEATHER PATTERN.  WITH LOW PRESSURE DEVELOPING OVER THE GREAT
BASIN OVERNIGHT AND HIGH PRESSURE SLIDING DOWN FROM MONTANA...WIND
WILL TURN NORTHERLY AND EASTERLY AFTER 06Z SATURDAY WITH SOME GUSTS
TO 20 KNOTS AROUND RKS AND HIGHER TERRAIN.  SOME WEAK CONVECTIVE
ACTIVITY POSSIBLE LATE THIS AFTERNOON INTO THE EVENING HOURS OVER
ABSAROKAS AND BIGHORN MOUNTAINS...WITH SLIGHT CHANCE OF IMPACT FROM
KBYG AND KCPR.  SATURDAY LOOKS A BIT DRIER WITH GENERALLY LIGHT WINDS
AS WELL.

&&

.FIRE WEATHER...

GENERALLY QUIET WEATHER PATTERN THROUGH SUNDAY MORNING OVER THE
AREA WITH NEAR SEASONAL TEMPERATURES AND LOW RELATIVE HUMIDITY AT
THE SURFACE. AFTERNOON RH VALUES IN THE LOW TEENS AND UPPER SINGLE
DIGITS WILL CONTINUE INTO SATURDAY...WITH POOR OVERNIGHT RECOVERY
EXCEPT IN THE VALLEYS OF WESTERN WY. WINDS WILL REMAIN GENERALLY
LIGHT...EXCEPT FOR SOME ENHANCED NORTHEAST FLOW OVER SOUTHERN
WYOMING BOTH FRIDAY NIGHT AND SATURDAY NIGHT DUE TO SURFACE LOW
PRESSURE DEVELOPING OVER THE GREAT BASIN. SATURDAY LOOKS TO BE
MOSTLY CLEAR...WHILE SUNDAY SHOULD SEE INCREASING CLOUDINESS FROM
THE SOUTHWEST...WITH SHOWERS AND ISOLATED THUNDERSTORMS MOVING IN
SUNDAY EVENING. SUNDAY SHOULD SEE ABOVE NORMAL TEMPERATURES IN THE
MID 90S IN THE CENTRAL BASINS.

&&

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

&&

$$

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



000
FXUS65 KCYS 311744
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
1145 AM MDT FRI JUL 31 2015

.SHORT TERM...(TODAY AND SUNDAY NIGHT)
ISSUED AT 300 AM MDT FRI JUL 31 2015

TODAY...FLOW ALOFT IS NORTHWEST. INCREASED LOW LEVEL MOISTURE FROM
24 HOURS AGO. DECENT 850/700 MB THETA-E RIDGE AXIS ACROSS SOUTHEAST
WYOMING WITH LOW LEVEL POSITIVE THETA-E ADVECTION...THUS AGREE WITH
THE NAM DEPICTION OF ISOLATED AFTERNOON THUNDERSTORMS ALONG AND EAST
OF INTERSTATE 25.

TONIGHT...THUNDERSTORMS WILL DIE OFF WITH LOSS OF DAYTIME HEATING IN
THE ABSENCE OF UPPER LEVEL ENERGY.

SATURDAY...LOW AND MID LEVEL WINDS SWITCH TO A NORTH DIRECTION WITH
DRIER AND MORE STABLE AIRMASS IN PLACE...THOUGH STILL ENOUGH
INSTABILITY FOR A SLIGHT CHANCE OF AFTERNOON THUNDERSTORMS MAINLY
ACROSS WESTERN NEBRASKA.

SATURDAY NIGHT/SUNDAY/SUNDAY NIGHT...FLOW ALOFT REMAINS NORTHWEST.
LOW AND MID LEVEL THETA-E RIDGE AXIS WILL LIE JUST SOUTH OF THE
COLORADO STATE LINE AND THERE WILL BE ENOUGH POSITIVE THETA-E
ADVECTION FOR ISOLATED THUNDERSTORMS JUST NORTH OF THE STATE LINE IN
THE AFTERNOON...THEN STORMS ENDING IN THE EVENING WITH LOSS OF
DAYTIME HEATING.

.LONG TERM...(MONDAY THROUGH THURSDAY)
ISSUED AT 300 AM MDT FRI JUL 31 2015

RIDGE AXIS STILL FORECAST TO DRIFT OFF TO THE EAST OF THE CHEYENNE
CWFA MONDAY ALLOWING MONSOONAL MOISTURE TO DRIFT NORTH INTO THE
AREA. SHORTWAVE ENERGY MONDAY NIGHT INTO TUESDAY MORNING MOVES
THROUGH THE AREA. BOTH THE GFS AND ECMWF SHOW THIS HAPPENING.
ECMWF MORE BULLISH ON QPF WHILE GFS KEEP MOST RAINFALL SOUTH IN
COLORADO. FOLLOWED THE ECMWF SOLUTION IN OUR FORECAST AND RAISED
POPS OVER GUIDANCE MONDAY AFTERNOON AND EVENING.

NEED TO BE WATCHING TUESDAY AND WEDNESDAY AS WE COULD BE LOOKING
AT SEVERE THUNDERSTORMS. HAVE A 60KT JET MOVING OVER THE AREA THAT
WILL INTERACT WITH A STALLED OUT FRONTAL BOUNDARY EAST OF THE
LARAMIE RANGE. GFS HAS JET FURTHER NORTH THAN THE ECMWF. WEATHER
DEFINITELY MORE UNSETTLED THROUGH MUCH OF NEXT WEEK.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH SATURDAY MORNING)

CURRENT RADAR LOOP SHOWS CONVECTION DEVELOPING NEAR KCYS LATE THIS
MORNING...MAINLY ALONG THE SOUTHERN LARAMIE RANGE. THIS ACTIVITY
WILL GRADUALLY MOVE AND DEVELOP FURTHER EAST ALONG THE CHEYENNE
RIDGE TOWARDS KSNY THIS AFTERNOON. CONTINUED WITH VCTS FROM KLAR TO
KSNY INTO THIS EVENING. OTHERWISE...VFR CONDITIONS ARE EXPECTED
OUTSIDE ANY TSTORM ACTIVITY WITH LIGHT WINDS.
&&

.FIRE WEATHER...
ISSUED AT 152 AM MDT FRI JUL 31 2015

LOW AFTERNOON RELATIVE HUMIDITIES AGAIN IN THE
AFTERNOON WEST OF INTERSTATE 25 THE NEXT FEW DAYS...THOUGH
FORTUNATELY WINDS WILL BE RELATIVELY LIGHT.

&&

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

$$

SHORT TERM...RUBIN
LONG TERM...GCC
AVIATION...TJT
FIRE WEATHER...RUBIN




000
FXUS65 KCYS 311744
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
1145 AM MDT FRI JUL 31 2015

.SHORT TERM...(TODAY AND SUNDAY NIGHT)
ISSUED AT 300 AM MDT FRI JUL 31 2015

TODAY...FLOW ALOFT IS NORTHWEST. INCREASED LOW LEVEL MOISTURE FROM
24 HOURS AGO. DECENT 850/700 MB THETA-E RIDGE AXIS ACROSS SOUTHEAST
WYOMING WITH LOW LEVEL POSITIVE THETA-E ADVECTION...THUS AGREE WITH
THE NAM DEPICTION OF ISOLATED AFTERNOON THUNDERSTORMS ALONG AND EAST
OF INTERSTATE 25.

TONIGHT...THUNDERSTORMS WILL DIE OFF WITH LOSS OF DAYTIME HEATING IN
THE ABSENCE OF UPPER LEVEL ENERGY.

SATURDAY...LOW AND MID LEVEL WINDS SWITCH TO A NORTH DIRECTION WITH
DRIER AND MORE STABLE AIRMASS IN PLACE...THOUGH STILL ENOUGH
INSTABILITY FOR A SLIGHT CHANCE OF AFTERNOON THUNDERSTORMS MAINLY
ACROSS WESTERN NEBRASKA.

SATURDAY NIGHT/SUNDAY/SUNDAY NIGHT...FLOW ALOFT REMAINS NORTHWEST.
LOW AND MID LEVEL THETA-E RIDGE AXIS WILL LIE JUST SOUTH OF THE
COLORADO STATE LINE AND THERE WILL BE ENOUGH POSITIVE THETA-E
ADVECTION FOR ISOLATED THUNDERSTORMS JUST NORTH OF THE STATE LINE IN
THE AFTERNOON...THEN STORMS ENDING IN THE EVENING WITH LOSS OF
DAYTIME HEATING.

.LONG TERM...(MONDAY THROUGH THURSDAY)
ISSUED AT 300 AM MDT FRI JUL 31 2015

RIDGE AXIS STILL FORECAST TO DRIFT OFF TO THE EAST OF THE CHEYENNE
CWFA MONDAY ALLOWING MONSOONAL MOISTURE TO DRIFT NORTH INTO THE
AREA. SHORTWAVE ENERGY MONDAY NIGHT INTO TUESDAY MORNING MOVES
THROUGH THE AREA. BOTH THE GFS AND ECMWF SHOW THIS HAPPENING.
ECMWF MORE BULLISH ON QPF WHILE GFS KEEP MOST RAINFALL SOUTH IN
COLORADO. FOLLOWED THE ECMWF SOLUTION IN OUR FORECAST AND RAISED
POPS OVER GUIDANCE MONDAY AFTERNOON AND EVENING.

NEED TO BE WATCHING TUESDAY AND WEDNESDAY AS WE COULD BE LOOKING
AT SEVERE THUNDERSTORMS. HAVE A 60KT JET MOVING OVER THE AREA THAT
WILL INTERACT WITH A STALLED OUT FRONTAL BOUNDARY EAST OF THE
LARAMIE RANGE. GFS HAS JET FURTHER NORTH THAN THE ECMWF. WEATHER
DEFINITELY MORE UNSETTLED THROUGH MUCH OF NEXT WEEK.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH SATURDAY MORNING)

CURRENT RADAR LOOP SHOWS CONVECTION DEVELOPING NEAR KCYS LATE THIS
MORNING...MAINLY ALONG THE SOUTHERN LARAMIE RANGE. THIS ACTIVITY
WILL GRADUALLY MOVE AND DEVELOP FURTHER EAST ALONG THE CHEYENNE
RIDGE TOWARDS KSNY THIS AFTERNOON. CONTINUED WITH VCTS FROM KLAR TO
KSNY INTO THIS EVENING. OTHERWISE...VFR CONDITIONS ARE EXPECTED
OUTSIDE ANY TSTORM ACTIVITY WITH LIGHT WINDS.
&&

.FIRE WEATHER...
ISSUED AT 152 AM MDT FRI JUL 31 2015

LOW AFTERNOON RELATIVE HUMIDITIES AGAIN IN THE
AFTERNOON WEST OF INTERSTATE 25 THE NEXT FEW DAYS...THOUGH
FORTUNATELY WINDS WILL BE RELATIVELY LIGHT.

&&

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

$$

SHORT TERM...RUBIN
LONG TERM...GCC
AVIATION...TJT
FIRE WEATHER...RUBIN




000
FXUS65 KCYS 311744
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
1145 AM MDT FRI JUL 31 2015

.SHORT TERM...(TODAY AND SUNDAY NIGHT)
ISSUED AT 300 AM MDT FRI JUL 31 2015

TODAY...FLOW ALOFT IS NORTHWEST. INCREASED LOW LEVEL MOISTURE FROM
24 HOURS AGO. DECENT 850/700 MB THETA-E RIDGE AXIS ACROSS SOUTHEAST
WYOMING WITH LOW LEVEL POSITIVE THETA-E ADVECTION...THUS AGREE WITH
THE NAM DEPICTION OF ISOLATED AFTERNOON THUNDERSTORMS ALONG AND EAST
OF INTERSTATE 25.

TONIGHT...THUNDERSTORMS WILL DIE OFF WITH LOSS OF DAYTIME HEATING IN
THE ABSENCE OF UPPER LEVEL ENERGY.

SATURDAY...LOW AND MID LEVEL WINDS SWITCH TO A NORTH DIRECTION WITH
DRIER AND MORE STABLE AIRMASS IN PLACE...THOUGH STILL ENOUGH
INSTABILITY FOR A SLIGHT CHANCE OF AFTERNOON THUNDERSTORMS MAINLY
ACROSS WESTERN NEBRASKA.

SATURDAY NIGHT/SUNDAY/SUNDAY NIGHT...FLOW ALOFT REMAINS NORTHWEST.
LOW AND MID LEVEL THETA-E RIDGE AXIS WILL LIE JUST SOUTH OF THE
COLORADO STATE LINE AND THERE WILL BE ENOUGH POSITIVE THETA-E
ADVECTION FOR ISOLATED THUNDERSTORMS JUST NORTH OF THE STATE LINE IN
THE AFTERNOON...THEN STORMS ENDING IN THE EVENING WITH LOSS OF
DAYTIME HEATING.

.LONG TERM...(MONDAY THROUGH THURSDAY)
ISSUED AT 300 AM MDT FRI JUL 31 2015

RIDGE AXIS STILL FORECAST TO DRIFT OFF TO THE EAST OF THE CHEYENNE
CWFA MONDAY ALLOWING MONSOONAL MOISTURE TO DRIFT NORTH INTO THE
AREA. SHORTWAVE ENERGY MONDAY NIGHT INTO TUESDAY MORNING MOVES
THROUGH THE AREA. BOTH THE GFS AND ECMWF SHOW THIS HAPPENING.
ECMWF MORE BULLISH ON QPF WHILE GFS KEEP MOST RAINFALL SOUTH IN
COLORADO. FOLLOWED THE ECMWF SOLUTION IN OUR FORECAST AND RAISED
POPS OVER GUIDANCE MONDAY AFTERNOON AND EVENING.

NEED TO BE WATCHING TUESDAY AND WEDNESDAY AS WE COULD BE LOOKING
AT SEVERE THUNDERSTORMS. HAVE A 60KT JET MOVING OVER THE AREA THAT
WILL INTERACT WITH A STALLED OUT FRONTAL BOUNDARY EAST OF THE
LARAMIE RANGE. GFS HAS JET FURTHER NORTH THAN THE ECMWF. WEATHER
DEFINITELY MORE UNSETTLED THROUGH MUCH OF NEXT WEEK.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH SATURDAY MORNING)

CURRENT RADAR LOOP SHOWS CONVECTION DEVELOPING NEAR KCYS LATE THIS
MORNING...MAINLY ALONG THE SOUTHERN LARAMIE RANGE. THIS ACTIVITY
WILL GRADUALLY MOVE AND DEVELOP FURTHER EAST ALONG THE CHEYENNE
RIDGE TOWARDS KSNY THIS AFTERNOON. CONTINUED WITH VCTS FROM KLAR TO
KSNY INTO THIS EVENING. OTHERWISE...VFR CONDITIONS ARE EXPECTED
OUTSIDE ANY TSTORM ACTIVITY WITH LIGHT WINDS.
&&

.FIRE WEATHER...
ISSUED AT 152 AM MDT FRI JUL 31 2015

LOW AFTERNOON RELATIVE HUMIDITIES AGAIN IN THE
AFTERNOON WEST OF INTERSTATE 25 THE NEXT FEW DAYS...THOUGH
FORTUNATELY WINDS WILL BE RELATIVELY LIGHT.

&&

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

$$

SHORT TERM...RUBIN
LONG TERM...GCC
AVIATION...TJT
FIRE WEATHER...RUBIN




000
FXUS65 KCYS 311744
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
1145 AM MDT FRI JUL 31 2015

.SHORT TERM...(TODAY AND SUNDAY NIGHT)
ISSUED AT 300 AM MDT FRI JUL 31 2015

TODAY...FLOW ALOFT IS NORTHWEST. INCREASED LOW LEVEL MOISTURE FROM
24 HOURS AGO. DECENT 850/700 MB THETA-E RIDGE AXIS ACROSS SOUTHEAST
WYOMING WITH LOW LEVEL POSITIVE THETA-E ADVECTION...THUS AGREE WITH
THE NAM DEPICTION OF ISOLATED AFTERNOON THUNDERSTORMS ALONG AND EAST
OF INTERSTATE 25.

TONIGHT...THUNDERSTORMS WILL DIE OFF WITH LOSS OF DAYTIME HEATING IN
THE ABSENCE OF UPPER LEVEL ENERGY.

SATURDAY...LOW AND MID LEVEL WINDS SWITCH TO A NORTH DIRECTION WITH
DRIER AND MORE STABLE AIRMASS IN PLACE...THOUGH STILL ENOUGH
INSTABILITY FOR A SLIGHT CHANCE OF AFTERNOON THUNDERSTORMS MAINLY
ACROSS WESTERN NEBRASKA.

SATURDAY NIGHT/SUNDAY/SUNDAY NIGHT...FLOW ALOFT REMAINS NORTHWEST.
LOW AND MID LEVEL THETA-E RIDGE AXIS WILL LIE JUST SOUTH OF THE
COLORADO STATE LINE AND THERE WILL BE ENOUGH POSITIVE THETA-E
ADVECTION FOR ISOLATED THUNDERSTORMS JUST NORTH OF THE STATE LINE IN
THE AFTERNOON...THEN STORMS ENDING IN THE EVENING WITH LOSS OF
DAYTIME HEATING.

.LONG TERM...(MONDAY THROUGH THURSDAY)
ISSUED AT 300 AM MDT FRI JUL 31 2015

RIDGE AXIS STILL FORECAST TO DRIFT OFF TO THE EAST OF THE CHEYENNE
CWFA MONDAY ALLOWING MONSOONAL MOISTURE TO DRIFT NORTH INTO THE
AREA. SHORTWAVE ENERGY MONDAY NIGHT INTO TUESDAY MORNING MOVES
THROUGH THE AREA. BOTH THE GFS AND ECMWF SHOW THIS HAPPENING.
ECMWF MORE BULLISH ON QPF WHILE GFS KEEP MOST RAINFALL SOUTH IN
COLORADO. FOLLOWED THE ECMWF SOLUTION IN OUR FORECAST AND RAISED
POPS OVER GUIDANCE MONDAY AFTERNOON AND EVENING.

NEED TO BE WATCHING TUESDAY AND WEDNESDAY AS WE COULD BE LOOKING
AT SEVERE THUNDERSTORMS. HAVE A 60KT JET MOVING OVER THE AREA THAT
WILL INTERACT WITH A STALLED OUT FRONTAL BOUNDARY EAST OF THE
LARAMIE RANGE. GFS HAS JET FURTHER NORTH THAN THE ECMWF. WEATHER
DEFINITELY MORE UNSETTLED THROUGH MUCH OF NEXT WEEK.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH SATURDAY MORNING)

CURRENT RADAR LOOP SHOWS CONVECTION DEVELOPING NEAR KCYS LATE THIS
MORNING...MAINLY ALONG THE SOUTHERN LARAMIE RANGE. THIS ACTIVITY
WILL GRADUALLY MOVE AND DEVELOP FURTHER EAST ALONG THE CHEYENNE
RIDGE TOWARDS KSNY THIS AFTERNOON. CONTINUED WITH VCTS FROM KLAR TO
KSNY INTO THIS EVENING. OTHERWISE...VFR CONDITIONS ARE EXPECTED
OUTSIDE ANY TSTORM ACTIVITY WITH LIGHT WINDS.
&&

.FIRE WEATHER...
ISSUED AT 152 AM MDT FRI JUL 31 2015

LOW AFTERNOON RELATIVE HUMIDITIES AGAIN IN THE
AFTERNOON WEST OF INTERSTATE 25 THE NEXT FEW DAYS...THOUGH
FORTUNATELY WINDS WILL BE RELATIVELY LIGHT.

&&

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

$$

SHORT TERM...RUBIN
LONG TERM...GCC
AVIATION...TJT
FIRE WEATHER...RUBIN




000
FXUS65 KCYS 311744
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
1145 AM MDT FRI JUL 31 2015

.SHORT TERM...(TODAY AND SUNDAY NIGHT)
ISSUED AT 300 AM MDT FRI JUL 31 2015

TODAY...FLOW ALOFT IS NORTHWEST. INCREASED LOW LEVEL MOISTURE FROM
24 HOURS AGO. DECENT 850/700 MB THETA-E RIDGE AXIS ACROSS SOUTHEAST
WYOMING WITH LOW LEVEL POSITIVE THETA-E ADVECTION...THUS AGREE WITH
THE NAM DEPICTION OF ISOLATED AFTERNOON THUNDERSTORMS ALONG AND EAST
OF INTERSTATE 25.

TONIGHT...THUNDERSTORMS WILL DIE OFF WITH LOSS OF DAYTIME HEATING IN
THE ABSENCE OF UPPER LEVEL ENERGY.

SATURDAY...LOW AND MID LEVEL WINDS SWITCH TO A NORTH DIRECTION WITH
DRIER AND MORE STABLE AIRMASS IN PLACE...THOUGH STILL ENOUGH
INSTABILITY FOR A SLIGHT CHANCE OF AFTERNOON THUNDERSTORMS MAINLY
ACROSS WESTERN NEBRASKA.

SATURDAY NIGHT/SUNDAY/SUNDAY NIGHT...FLOW ALOFT REMAINS NORTHWEST.
LOW AND MID LEVEL THETA-E RIDGE AXIS WILL LIE JUST SOUTH OF THE
COLORADO STATE LINE AND THERE WILL BE ENOUGH POSITIVE THETA-E
ADVECTION FOR ISOLATED THUNDERSTORMS JUST NORTH OF THE STATE LINE IN
THE AFTERNOON...THEN STORMS ENDING IN THE EVENING WITH LOSS OF
DAYTIME HEATING.

.LONG TERM...(MONDAY THROUGH THURSDAY)
ISSUED AT 300 AM MDT FRI JUL 31 2015

RIDGE AXIS STILL FORECAST TO DRIFT OFF TO THE EAST OF THE CHEYENNE
CWFA MONDAY ALLOWING MONSOONAL MOISTURE TO DRIFT NORTH INTO THE
AREA. SHORTWAVE ENERGY MONDAY NIGHT INTO TUESDAY MORNING MOVES
THROUGH THE AREA. BOTH THE GFS AND ECMWF SHOW THIS HAPPENING.
ECMWF MORE BULLISH ON QPF WHILE GFS KEEP MOST RAINFALL SOUTH IN
COLORADO. FOLLOWED THE ECMWF SOLUTION IN OUR FORECAST AND RAISED
POPS OVER GUIDANCE MONDAY AFTERNOON AND EVENING.

NEED TO BE WATCHING TUESDAY AND WEDNESDAY AS WE COULD BE LOOKING
AT SEVERE THUNDERSTORMS. HAVE A 60KT JET MOVING OVER THE AREA THAT
WILL INTERACT WITH A STALLED OUT FRONTAL BOUNDARY EAST OF THE
LARAMIE RANGE. GFS HAS JET FURTHER NORTH THAN THE ECMWF. WEATHER
DEFINITELY MORE UNSETTLED THROUGH MUCH OF NEXT WEEK.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH SATURDAY MORNING)

CURRENT RADAR LOOP SHOWS CONVECTION DEVELOPING NEAR KCYS LATE THIS
MORNING...MAINLY ALONG THE SOUTHERN LARAMIE RANGE. THIS ACTIVITY
WILL GRADUALLY MOVE AND DEVELOP FURTHER EAST ALONG THE CHEYENNE
RIDGE TOWARDS KSNY THIS AFTERNOON. CONTINUED WITH VCTS FROM KLAR TO
KSNY INTO THIS EVENING. OTHERWISE...VFR CONDITIONS ARE EXPECTED
OUTSIDE ANY TSTORM ACTIVITY WITH LIGHT WINDS.
&&

.FIRE WEATHER...
ISSUED AT 152 AM MDT FRI JUL 31 2015

LOW AFTERNOON RELATIVE HUMIDITIES AGAIN IN THE
AFTERNOON WEST OF INTERSTATE 25 THE NEXT FEW DAYS...THOUGH
FORTUNATELY WINDS WILL BE RELATIVELY LIGHT.

&&

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

$$

SHORT TERM...RUBIN
LONG TERM...GCC
AVIATION...TJT
FIRE WEATHER...RUBIN



000
FXUS65 KCYS 311744
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
1145 AM MDT FRI JUL 31 2015

.SHORT TERM...(TODAY AND SUNDAY NIGHT)
ISSUED AT 300 AM MDT FRI JUL 31 2015

TODAY...FLOW ALOFT IS NORTHWEST. INCREASED LOW LEVEL MOISTURE FROM
24 HOURS AGO. DECENT 850/700 MB THETA-E RIDGE AXIS ACROSS SOUTHEAST
WYOMING WITH LOW LEVEL POSITIVE THETA-E ADVECTION...THUS AGREE WITH
THE NAM DEPICTION OF ISOLATED AFTERNOON THUNDERSTORMS ALONG AND EAST
OF INTERSTATE 25.

TONIGHT...THUNDERSTORMS WILL DIE OFF WITH LOSS OF DAYTIME HEATING IN
THE ABSENCE OF UPPER LEVEL ENERGY.

SATURDAY...LOW AND MID LEVEL WINDS SWITCH TO A NORTH DIRECTION WITH
DRIER AND MORE STABLE AIRMASS IN PLACE...THOUGH STILL ENOUGH
INSTABILITY FOR A SLIGHT CHANCE OF AFTERNOON THUNDERSTORMS MAINLY
ACROSS WESTERN NEBRASKA.

SATURDAY NIGHT/SUNDAY/SUNDAY NIGHT...FLOW ALOFT REMAINS NORTHWEST.
LOW AND MID LEVEL THETA-E RIDGE AXIS WILL LIE JUST SOUTH OF THE
COLORADO STATE LINE AND THERE WILL BE ENOUGH POSITIVE THETA-E
ADVECTION FOR ISOLATED THUNDERSTORMS JUST NORTH OF THE STATE LINE IN
THE AFTERNOON...THEN STORMS ENDING IN THE EVENING WITH LOSS OF
DAYTIME HEATING.

.LONG TERM...(MONDAY THROUGH THURSDAY)
ISSUED AT 300 AM MDT FRI JUL 31 2015

RIDGE AXIS STILL FORECAST TO DRIFT OFF TO THE EAST OF THE CHEYENNE
CWFA MONDAY ALLOWING MONSOONAL MOISTURE TO DRIFT NORTH INTO THE
AREA. SHORTWAVE ENERGY MONDAY NIGHT INTO TUESDAY MORNING MOVES
THROUGH THE AREA. BOTH THE GFS AND ECMWF SHOW THIS HAPPENING.
ECMWF MORE BULLISH ON QPF WHILE GFS KEEP MOST RAINFALL SOUTH IN
COLORADO. FOLLOWED THE ECMWF SOLUTION IN OUR FORECAST AND RAISED
POPS OVER GUIDANCE MONDAY AFTERNOON AND EVENING.

NEED TO BE WATCHING TUESDAY AND WEDNESDAY AS WE COULD BE LOOKING
AT SEVERE THUNDERSTORMS. HAVE A 60KT JET MOVING OVER THE AREA THAT
WILL INTERACT WITH A STALLED OUT FRONTAL BOUNDARY EAST OF THE
LARAMIE RANGE. GFS HAS JET FURTHER NORTH THAN THE ECMWF. WEATHER
DEFINITELY MORE UNSETTLED THROUGH MUCH OF NEXT WEEK.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH SATURDAY MORNING)

CURRENT RADAR LOOP SHOWS CONVECTION DEVELOPING NEAR KCYS LATE THIS
MORNING...MAINLY ALONG THE SOUTHERN LARAMIE RANGE. THIS ACTIVITY
WILL GRADUALLY MOVE AND DEVELOP FURTHER EAST ALONG THE CHEYENNE
RIDGE TOWARDS KSNY THIS AFTERNOON. CONTINUED WITH VCTS FROM KLAR TO
KSNY INTO THIS EVENING. OTHERWISE...VFR CONDITIONS ARE EXPECTED
OUTSIDE ANY TSTORM ACTIVITY WITH LIGHT WINDS.
&&

.FIRE WEATHER...
ISSUED AT 152 AM MDT FRI JUL 31 2015

LOW AFTERNOON RELATIVE HUMIDITIES AGAIN IN THE
AFTERNOON WEST OF INTERSTATE 25 THE NEXT FEW DAYS...THOUGH
FORTUNATELY WINDS WILL BE RELATIVELY LIGHT.

&&

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

$$

SHORT TERM...RUBIN
LONG TERM...GCC
AVIATION...TJT
FIRE WEATHER...RUBIN




000
FXUS65 KRIW 311734
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
1133 AM MDT FRI JUL 31 2015

.SHORT TERM...TODAY THROUGH SUNDAY NIGHT

WV IMAGERY SHOWING RIDGE WRN CONUS...TROF ERN CONUS. UPR LVL CENTER
OF THIS HIGH LOCATED OVR NM WITH A SMALL BUT STRONGER EMBEDDED WAVE
OVR SFC LOW...VERY TROPICAL LOOKING...OVR THE NRN BAJA REGION.
UPSTREAM OVR WA...WEAK SW ATOP OF RIDGE WHICH WILL ARRIVE OVR NERN
WY THIS EVE. UPR BUBBLE WILL LARGELY PROTECT THE FA AND POINTS
WEST...FOR NOW...FROM MOST PRECIP ACTIVITY...KEEPING LOW CHANCES FOR
POPS OVR THE ERN CWA TO THE HIGH/CNTRL PLAINS. SFC HAS GENERAL HIGH
P ACROSS THE FA...WITH LOW P AND AN ATTENDANT WEAK WARM FRONT FROM
ERN UT INTO WRN CO.

HOT AND DRY FOR THE MOST PART WITH AMPLIFIED PORTION OF THE RIDGE
AXIS CAPPING MOST OF THE FA...KEEPING SHOWERS AND STORMS AT A
MINIMUM...LARGELY RELEGATED ON AN ISOLATED BASIS TO A FEW OF THE
HIGHEST PEAKS...SUCH AS THE ABSAROKAS AND BIGHORNS LATE TODAY/THIS
EVE. ADDITIONALLY TODAY...LOW P OVR UT WILL ALLOW FOR A WEAK WARM
FRONT TO BUILD ACROSS THE WY/CO BORDER AREA...LIFTING ACROSS ERN WY
INTO FRI EVENING WITH SOME MODEST MOISTURE RETURNING TO ERN
WY...WITH SOME LOW CHCS FOR THUNDER BY THIS EVENING AS A SMALL SW
TROF ARRIVES OVERHEAD THRU THE RIDGE THIS EVENING. ATTM...DOES NOT
LOOK LIKE MUCH OF THIS MOISTURE WILL MAKE IT BACK INTO THE ERN
ZONES...BUT CASPER MOUNTAIN...AND TO A LESSER EXTENT THE REST OF
NATRONA OR JOHNSON COUNTY MAY SEE AN ISOLATED LATE DAY T-STORM.
SATURDAY WILL BE WITHOUT PRECIP EVERYWHERE AS DRY AIR ADVECTS FROM
THE WEST OVR THE FA AND ANY SIGNIFICANT MOISTURE IS HELD AT BAY TO
THE SOUTH. SUNDAY...HOTTEST DAY OF THE PERIOD...BUT WEAK MOISTURE
DOES START TO SLOWLY WORK ITS WAY TOWARD AND INTO THE FA THRU THE
DAY...ALLOWING FOR LOW CHANCE PRECIP ACROSS FAVORED MOUNTAIN RANGES
LATER SUNDAY EVENING AND OVERNIGHT PERIOD. THIS WILL BE A PRECURSOR
TO SOMEWHAT BETTER CHCS FOR PRECIP LATER MONDAY...AS THE UPR RIDGE
AXIS ROTATES CLOCKWISE AND CENTERS THRU THE CENTER OF WY...AND SOME
MODEST MONSOONAL TYPE MOISTURE STARTS TO FEED ACROSS THE
INTERMOUNTAIN WEST JUST AHEAD OF  WHAT WAS THE BAJA DISTURBANCE
DESCRIBED ABOVE.

.LONG TERM...MONDAY THROUGH FRIDAY

IT APPEARS THAT THE LONG RANGE MODELS ARE NOW LATCHING ON TO A
WEATHER SYSTEM ROTATING THROUGH THE GREAT BASIN MONDAY. A PORTION
OF THIS WAVE MOVES INTO WY MONDAY AFTERNOON AND THEN PROGRESSES
NORTHWARD THROUGH TUESDAY MORNING. CURRENT FORECAST FOR MONDAY
THROUGH TUESDAY MORNING REFLECTS A HIGHER PRECIP CHANCE IN SOME
AREAS AND DID NOT ALTER THAT FORECAST MUCH. A SOUTHWEST FLOW ALOFT
IS FORECAST TUE PM THROUGH FRIDAY. THIS IS DUE TO AN UPPER LEVEL
STORM SYSTEM THAT ROTATES OFF THE WEST COAST OF CANADA TUESDAY AND
THEN GRADUALLY SINKS SOUTH TO JUST OFF THE NW COAST OF THE U.S.
NEXT FRIDAY. IN THIS SW FLOW ALOFT A FEW WEATHER DISTURBANCES PASS
THROUGH WHICH WOULD BRING A LITTLE HIGHER CHANCE OF STORMS. TIMING
THESE THAT FAR OUT IS NOT EASY OR CONSISTENT. THE 00Z RUNS BRING
ONE DISTURBANCE THROUGH ON WEDNESDAY FOLLOWED BY ANOTHER THURS
NIGHT. I ADJUSTED SOME PRECIP CHANCES ON THOSE DAYS AND NIGHTS BUT
I EXPECT THE TIMING TO CHANGE IN THE COMING DAYS. AS FOR
TEMPS...MONDAY NOW LOOKS COOLER DUE TO MORE CLOUDS AND GREATER
COVERAGE OF SHOWERS OR STORMS. TUE THROUGH FRIDAY WILL BE WARM TO
LOCALLY HOT WITH 80S TO LOW 90S FOR MOST LOWER ELEVATIONS...WITH
UPPER 70S TO LOW 80S IN THE WESTERN VALLEYS. AS STATED
PREVIOUSLY...THE LIGHTNING THAT IS PRODUCED BY THE STORMS NEXT
WEEK WILL LIKELY START SOME FIRES IN PLACES WHERE THE FUELS ARE
RIPE FOR BURNING. THIS THREAT WILL CONTINUE TO BE ANALYZED OVER
THE COMING DAYS.

&&

.AVIATION.../18Z ISSUANCE/

VFR CONDITIONS STILL EXPECTED THROUGH 00Z SUNDAY WITH RELATIVELY
QUIET WEATHER PATTERN.  WITH LOW PRESSURE DEVELOPING OVER THE GREAT
BASIN OVERNIGHT AND HIGH PRESSURE SLIDING DOWN FROM MONTANA...WIND
WILL TURN NORTHERLY AND EASTERLY AFTER 06Z SATURDAY WITH SOME GUSTS
TO 20 KNOTS AROUND RKS AND HIGHER TERRAIN.  SOME WEAK CONVECTIVE
ACTIVITY POSSIBLE LATE THIS AFTERNOON INTO THE EVENING HOURS OVER
ABSAROKAS AND BIGHORN MOUNTAINS...WITH SLIGHT CHANCE OF IMPACT FROM
KBYG AND KCPR.  SATURDAY LOOKS A BIT DRIER WITH GENERALLY LIGHT WINDS
AS WELL.

&&

.FIRE WEATHER...

MINIMUM RH VALUES ARE EXPECTED TO REMAIN IN THE SINGLE DIGITS TO LOW
TEENS THROUGH THE WEEKEND ACROSS THE SOUTH AND LOW ELEVATION AREAS
EAST OF THE DIVIDE...WITH UPPER TEENS AND 20S OVER THE MOUNTAINS.
RELATIVE HUMIDITY WILL HAVE LITTLE TIME RECOVERING
OVERNIGHT...ESPECIALLY AT MID SLOPE WHERE RHS MAY NOT RISE OUT OF
THE MID 20S IN THE CENTRAL WYOMING RANGES. GENERALLY LIGHT WINDS ARE
EXPECTED THROUGH THE WEEKEND...WITH ONLY A FEW LIGHT BREEZES
POSSIBLE IN THE AFTERNOON AND EVENINGS ACROSS THE LOWER ELEVATIONS
OF CENTRAL AND SOUTHERN WYOMING. OTHERWISE...A VERY DRY ATMOSPHERE
WITH HIGH PRESSURE AT THE SURFACE AND ALOFT WILL KEEP MOST CHANCES
FOR ANY PRECIPITATION ISOLATED AND RELEGATED TO MAINLY A FEW
MOUNTAIN OR EASTERN ZONES LATER TODAY. LITTLE IF ANY CHANCE FOR
SHOWERS/STORMS WILL OCCUR ON SATURDAY AT ANY LOCATION. SUNDAY WILL
SEE THE WARMEST TEMPERATURES OF THE WEEKEND...HOWEVER MOISTURE WILL
SLOWLY ALSO BE INCREASING WITH ISOLATED THUNDERSTORM CHANCES
RETURNING LATER IN THE DAY AND OVERNIGHT...WITH WIDELY SCATTERED
CHANCES FOR PRECIPITATION BY MONDAY AFTERNOON.

&&

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

&&

$$

SHORT TERM...BRAUN
LONG TERM...AR
AVIATION...MCDONALD
FIRE WEATHER...BRAUN




000
FXUS65 KRIW 311734
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
1133 AM MDT FRI JUL 31 2015

.SHORT TERM...TODAY THROUGH SUNDAY NIGHT

WV IMAGERY SHOWING RIDGE WRN CONUS...TROF ERN CONUS. UPR LVL CENTER
OF THIS HIGH LOCATED OVR NM WITH A SMALL BUT STRONGER EMBEDDED WAVE
OVR SFC LOW...VERY TROPICAL LOOKING...OVR THE NRN BAJA REGION.
UPSTREAM OVR WA...WEAK SW ATOP OF RIDGE WHICH WILL ARRIVE OVR NERN
WY THIS EVE. UPR BUBBLE WILL LARGELY PROTECT THE FA AND POINTS
WEST...FOR NOW...FROM MOST PRECIP ACTIVITY...KEEPING LOW CHANCES FOR
POPS OVR THE ERN CWA TO THE HIGH/CNTRL PLAINS. SFC HAS GENERAL HIGH
P ACROSS THE FA...WITH LOW P AND AN ATTENDANT WEAK WARM FRONT FROM
ERN UT INTO WRN CO.

HOT AND DRY FOR THE MOST PART WITH AMPLIFIED PORTION OF THE RIDGE
AXIS CAPPING MOST OF THE FA...KEEPING SHOWERS AND STORMS AT A
MINIMUM...LARGELY RELEGATED ON AN ISOLATED BASIS TO A FEW OF THE
HIGHEST PEAKS...SUCH AS THE ABSAROKAS AND BIGHORNS LATE TODAY/THIS
EVE. ADDITIONALLY TODAY...LOW P OVR UT WILL ALLOW FOR A WEAK WARM
FRONT TO BUILD ACROSS THE WY/CO BORDER AREA...LIFTING ACROSS ERN WY
INTO FRI EVENING WITH SOME MODEST MOISTURE RETURNING TO ERN
WY...WITH SOME LOW CHCS FOR THUNDER BY THIS EVENING AS A SMALL SW
TROF ARRIVES OVERHEAD THRU THE RIDGE THIS EVENING. ATTM...DOES NOT
LOOK LIKE MUCH OF THIS MOISTURE WILL MAKE IT BACK INTO THE ERN
ZONES...BUT CASPER MOUNTAIN...AND TO A LESSER EXTENT THE REST OF
NATRONA OR JOHNSON COUNTY MAY SEE AN ISOLATED LATE DAY T-STORM.
SATURDAY WILL BE WITHOUT PRECIP EVERYWHERE AS DRY AIR ADVECTS FROM
THE WEST OVR THE FA AND ANY SIGNIFICANT MOISTURE IS HELD AT BAY TO
THE SOUTH. SUNDAY...HOTTEST DAY OF THE PERIOD...BUT WEAK MOISTURE
DOES START TO SLOWLY WORK ITS WAY TOWARD AND INTO THE FA THRU THE
DAY...ALLOWING FOR LOW CHANCE PRECIP ACROSS FAVORED MOUNTAIN RANGES
LATER SUNDAY EVENING AND OVERNIGHT PERIOD. THIS WILL BE A PRECURSOR
TO SOMEWHAT BETTER CHCS FOR PRECIP LATER MONDAY...AS THE UPR RIDGE
AXIS ROTATES CLOCKWISE AND CENTERS THRU THE CENTER OF WY...AND SOME
MODEST MONSOONAL TYPE MOISTURE STARTS TO FEED ACROSS THE
INTERMOUNTAIN WEST JUST AHEAD OF  WHAT WAS THE BAJA DISTURBANCE
DESCRIBED ABOVE.

.LONG TERM...MONDAY THROUGH FRIDAY

IT APPEARS THAT THE LONG RANGE MODELS ARE NOW LATCHING ON TO A
WEATHER SYSTEM ROTATING THROUGH THE GREAT BASIN MONDAY. A PORTION
OF THIS WAVE MOVES INTO WY MONDAY AFTERNOON AND THEN PROGRESSES
NORTHWARD THROUGH TUESDAY MORNING. CURRENT FORECAST FOR MONDAY
THROUGH TUESDAY MORNING REFLECTS A HIGHER PRECIP CHANCE IN SOME
AREAS AND DID NOT ALTER THAT FORECAST MUCH. A SOUTHWEST FLOW ALOFT
IS FORECAST TUE PM THROUGH FRIDAY. THIS IS DUE TO AN UPPER LEVEL
STORM SYSTEM THAT ROTATES OFF THE WEST COAST OF CANADA TUESDAY AND
THEN GRADUALLY SINKS SOUTH TO JUST OFF THE NW COAST OF THE U.S.
NEXT FRIDAY. IN THIS SW FLOW ALOFT A FEW WEATHER DISTURBANCES PASS
THROUGH WHICH WOULD BRING A LITTLE HIGHER CHANCE OF STORMS. TIMING
THESE THAT FAR OUT IS NOT EASY OR CONSISTENT. THE 00Z RUNS BRING
ONE DISTURBANCE THROUGH ON WEDNESDAY FOLLOWED BY ANOTHER THURS
NIGHT. I ADJUSTED SOME PRECIP CHANCES ON THOSE DAYS AND NIGHTS BUT
I EXPECT THE TIMING TO CHANGE IN THE COMING DAYS. AS FOR
TEMPS...MONDAY NOW LOOKS COOLER DUE TO MORE CLOUDS AND GREATER
COVERAGE OF SHOWERS OR STORMS. TUE THROUGH FRIDAY WILL BE WARM TO
LOCALLY HOT WITH 80S TO LOW 90S FOR MOST LOWER ELEVATIONS...WITH
UPPER 70S TO LOW 80S IN THE WESTERN VALLEYS. AS STATED
PREVIOUSLY...THE LIGHTNING THAT IS PRODUCED BY THE STORMS NEXT
WEEK WILL LIKELY START SOME FIRES IN PLACES WHERE THE FUELS ARE
RIPE FOR BURNING. THIS THREAT WILL CONTINUE TO BE ANALYZED OVER
THE COMING DAYS.

&&

.AVIATION.../18Z ISSUANCE/

VFR CONDITIONS STILL EXPECTED THROUGH 00Z SUNDAY WITH RELATIVELY
QUIET WEATHER PATTERN.  WITH LOW PRESSURE DEVELOPING OVER THE GREAT
BASIN OVERNIGHT AND HIGH PRESSURE SLIDING DOWN FROM MONTANA...WIND
WILL TURN NORTHERLY AND EASTERLY AFTER 06Z SATURDAY WITH SOME GUSTS
TO 20 KNOTS AROUND RKS AND HIGHER TERRAIN.  SOME WEAK CONVECTIVE
ACTIVITY POSSIBLE LATE THIS AFTERNOON INTO THE EVENING HOURS OVER
ABSAROKAS AND BIGHORN MOUNTAINS...WITH SLIGHT CHANCE OF IMPACT FROM
KBYG AND KCPR.  SATURDAY LOOKS A BIT DRIER WITH GENERALLY LIGHT WINDS
AS WELL.

&&

.FIRE WEATHER...

MINIMUM RH VALUES ARE EXPECTED TO REMAIN IN THE SINGLE DIGITS TO LOW
TEENS THROUGH THE WEEKEND ACROSS THE SOUTH AND LOW ELEVATION AREAS
EAST OF THE DIVIDE...WITH UPPER TEENS AND 20S OVER THE MOUNTAINS.
RELATIVE HUMIDITY WILL HAVE LITTLE TIME RECOVERING
OVERNIGHT...ESPECIALLY AT MID SLOPE WHERE RHS MAY NOT RISE OUT OF
THE MID 20S IN THE CENTRAL WYOMING RANGES. GENERALLY LIGHT WINDS ARE
EXPECTED THROUGH THE WEEKEND...WITH ONLY A FEW LIGHT BREEZES
POSSIBLE IN THE AFTERNOON AND EVENINGS ACROSS THE LOWER ELEVATIONS
OF CENTRAL AND SOUTHERN WYOMING. OTHERWISE...A VERY DRY ATMOSPHERE
WITH HIGH PRESSURE AT THE SURFACE AND ALOFT WILL KEEP MOST CHANCES
FOR ANY PRECIPITATION ISOLATED AND RELEGATED TO MAINLY A FEW
MOUNTAIN OR EASTERN ZONES LATER TODAY. LITTLE IF ANY CHANCE FOR
SHOWERS/STORMS WILL OCCUR ON SATURDAY AT ANY LOCATION. SUNDAY WILL
SEE THE WARMEST TEMPERATURES OF THE WEEKEND...HOWEVER MOISTURE WILL
SLOWLY ALSO BE INCREASING WITH ISOLATED THUNDERSTORM CHANCES
RETURNING LATER IN THE DAY AND OVERNIGHT...WITH WIDELY SCATTERED
CHANCES FOR PRECIPITATION BY MONDAY AFTERNOON.

&&

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

&&

$$

SHORT TERM...BRAUN
LONG TERM...AR
AVIATION...MCDONALD
FIRE WEATHER...BRAUN




000
FXUS65 KRIW 311734
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
1133 AM MDT FRI JUL 31 2015

.SHORT TERM...TODAY THROUGH SUNDAY NIGHT

WV IMAGERY SHOWING RIDGE WRN CONUS...TROF ERN CONUS. UPR LVL CENTER
OF THIS HIGH LOCATED OVR NM WITH A SMALL BUT STRONGER EMBEDDED WAVE
OVR SFC LOW...VERY TROPICAL LOOKING...OVR THE NRN BAJA REGION.
UPSTREAM OVR WA...WEAK SW ATOP OF RIDGE WHICH WILL ARRIVE OVR NERN
WY THIS EVE. UPR BUBBLE WILL LARGELY PROTECT THE FA AND POINTS
WEST...FOR NOW...FROM MOST PRECIP ACTIVITY...KEEPING LOW CHANCES FOR
POPS OVR THE ERN CWA TO THE HIGH/CNTRL PLAINS. SFC HAS GENERAL HIGH
P ACROSS THE FA...WITH LOW P AND AN ATTENDANT WEAK WARM FRONT FROM
ERN UT INTO WRN CO.

HOT AND DRY FOR THE MOST PART WITH AMPLIFIED PORTION OF THE RIDGE
AXIS CAPPING MOST OF THE FA...KEEPING SHOWERS AND STORMS AT A
MINIMUM...LARGELY RELEGATED ON AN ISOLATED BASIS TO A FEW OF THE
HIGHEST PEAKS...SUCH AS THE ABSAROKAS AND BIGHORNS LATE TODAY/THIS
EVE. ADDITIONALLY TODAY...LOW P OVR UT WILL ALLOW FOR A WEAK WARM
FRONT TO BUILD ACROSS THE WY/CO BORDER AREA...LIFTING ACROSS ERN WY
INTO FRI EVENING WITH SOME MODEST MOISTURE RETURNING TO ERN
WY...WITH SOME LOW CHCS FOR THUNDER BY THIS EVENING AS A SMALL SW
TROF ARRIVES OVERHEAD THRU THE RIDGE THIS EVENING. ATTM...DOES NOT
LOOK LIKE MUCH OF THIS MOISTURE WILL MAKE IT BACK INTO THE ERN
ZONES...BUT CASPER MOUNTAIN...AND TO A LESSER EXTENT THE REST OF
NATRONA OR JOHNSON COUNTY MAY SEE AN ISOLATED LATE DAY T-STORM.
SATURDAY WILL BE WITHOUT PRECIP EVERYWHERE AS DRY AIR ADVECTS FROM
THE WEST OVR THE FA AND ANY SIGNIFICANT MOISTURE IS HELD AT BAY TO
THE SOUTH. SUNDAY...HOTTEST DAY OF THE PERIOD...BUT WEAK MOISTURE
DOES START TO SLOWLY WORK ITS WAY TOWARD AND INTO THE FA THRU THE
DAY...ALLOWING FOR LOW CHANCE PRECIP ACROSS FAVORED MOUNTAIN RANGES
LATER SUNDAY EVENING AND OVERNIGHT PERIOD. THIS WILL BE A PRECURSOR
TO SOMEWHAT BETTER CHCS FOR PRECIP LATER MONDAY...AS THE UPR RIDGE
AXIS ROTATES CLOCKWISE AND CENTERS THRU THE CENTER OF WY...AND SOME
MODEST MONSOONAL TYPE MOISTURE STARTS TO FEED ACROSS THE
INTERMOUNTAIN WEST JUST AHEAD OF  WHAT WAS THE BAJA DISTURBANCE
DESCRIBED ABOVE.

.LONG TERM...MONDAY THROUGH FRIDAY

IT APPEARS THAT THE LONG RANGE MODELS ARE NOW LATCHING ON TO A
WEATHER SYSTEM ROTATING THROUGH THE GREAT BASIN MONDAY. A PORTION
OF THIS WAVE MOVES INTO WY MONDAY AFTERNOON AND THEN PROGRESSES
NORTHWARD THROUGH TUESDAY MORNING. CURRENT FORECAST FOR MONDAY
THROUGH TUESDAY MORNING REFLECTS A HIGHER PRECIP CHANCE IN SOME
AREAS AND DID NOT ALTER THAT FORECAST MUCH. A SOUTHWEST FLOW ALOFT
IS FORECAST TUE PM THROUGH FRIDAY. THIS IS DUE TO AN UPPER LEVEL
STORM SYSTEM THAT ROTATES OFF THE WEST COAST OF CANADA TUESDAY AND
THEN GRADUALLY SINKS SOUTH TO JUST OFF THE NW COAST OF THE U.S.
NEXT FRIDAY. IN THIS SW FLOW ALOFT A FEW WEATHER DISTURBANCES PASS
THROUGH WHICH WOULD BRING A LITTLE HIGHER CHANCE OF STORMS. TIMING
THESE THAT FAR OUT IS NOT EASY OR CONSISTENT. THE 00Z RUNS BRING
ONE DISTURBANCE THROUGH ON WEDNESDAY FOLLOWED BY ANOTHER THURS
NIGHT. I ADJUSTED SOME PRECIP CHANCES ON THOSE DAYS AND NIGHTS BUT
I EXPECT THE TIMING TO CHANGE IN THE COMING DAYS. AS FOR
TEMPS...MONDAY NOW LOOKS COOLER DUE TO MORE CLOUDS AND GREATER
COVERAGE OF SHOWERS OR STORMS. TUE THROUGH FRIDAY WILL BE WARM TO
LOCALLY HOT WITH 80S TO LOW 90S FOR MOST LOWER ELEVATIONS...WITH
UPPER 70S TO LOW 80S IN THE WESTERN VALLEYS. AS STATED
PREVIOUSLY...THE LIGHTNING THAT IS PRODUCED BY THE STORMS NEXT
WEEK WILL LIKELY START SOME FIRES IN PLACES WHERE THE FUELS ARE
RIPE FOR BURNING. THIS THREAT WILL CONTINUE TO BE ANALYZED OVER
THE COMING DAYS.

&&

.AVIATION.../18Z ISSUANCE/

VFR CONDITIONS STILL EXPECTED THROUGH 00Z SUNDAY WITH RELATIVELY
QUIET WEATHER PATTERN.  WITH LOW PRESSURE DEVELOPING OVER THE GREAT
BASIN OVERNIGHT AND HIGH PRESSURE SLIDING DOWN FROM MONTANA...WIND
WILL TURN NORTHERLY AND EASTERLY AFTER 06Z SATURDAY WITH SOME GUSTS
TO 20 KNOTS AROUND RKS AND HIGHER TERRAIN.  SOME WEAK CONVECTIVE
ACTIVITY POSSIBLE LATE THIS AFTERNOON INTO THE EVENING HOURS OVER
ABSAROKAS AND BIGHORN MOUNTAINS...WITH SLIGHT CHANCE OF IMPACT FROM
KBYG AND KCPR.  SATURDAY LOOKS A BIT DRIER WITH GENERALLY LIGHT WINDS
AS WELL.

&&

.FIRE WEATHER...

MINIMUM RH VALUES ARE EXPECTED TO REMAIN IN THE SINGLE DIGITS TO LOW
TEENS THROUGH THE WEEKEND ACROSS THE SOUTH AND LOW ELEVATION AREAS
EAST OF THE DIVIDE...WITH UPPER TEENS AND 20S OVER THE MOUNTAINS.
RELATIVE HUMIDITY WILL HAVE LITTLE TIME RECOVERING
OVERNIGHT...ESPECIALLY AT MID SLOPE WHERE RHS MAY NOT RISE OUT OF
THE MID 20S IN THE CENTRAL WYOMING RANGES. GENERALLY LIGHT WINDS ARE
EXPECTED THROUGH THE WEEKEND...WITH ONLY A FEW LIGHT BREEZES
POSSIBLE IN THE AFTERNOON AND EVENINGS ACROSS THE LOWER ELEVATIONS
OF CENTRAL AND SOUTHERN WYOMING. OTHERWISE...A VERY DRY ATMOSPHERE
WITH HIGH PRESSURE AT THE SURFACE AND ALOFT WILL KEEP MOST CHANCES
FOR ANY PRECIPITATION ISOLATED AND RELEGATED TO MAINLY A FEW
MOUNTAIN OR EASTERN ZONES LATER TODAY. LITTLE IF ANY CHANCE FOR
SHOWERS/STORMS WILL OCCUR ON SATURDAY AT ANY LOCATION. SUNDAY WILL
SEE THE WARMEST TEMPERATURES OF THE WEEKEND...HOWEVER MOISTURE WILL
SLOWLY ALSO BE INCREASING WITH ISOLATED THUNDERSTORM CHANCES
RETURNING LATER IN THE DAY AND OVERNIGHT...WITH WIDELY SCATTERED
CHANCES FOR PRECIPITATION BY MONDAY AFTERNOON.

&&

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

&&

$$

SHORT TERM...BRAUN
LONG TERM...AR
AVIATION...MCDONALD
FIRE WEATHER...BRAUN




000
FXUS65 KRIW 311734
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
1133 AM MDT FRI JUL 31 2015

.SHORT TERM...TODAY THROUGH SUNDAY NIGHT

WV IMAGERY SHOWING RIDGE WRN CONUS...TROF ERN CONUS. UPR LVL CENTER
OF THIS HIGH LOCATED OVR NM WITH A SMALL BUT STRONGER EMBEDDED WAVE
OVR SFC LOW...VERY TROPICAL LOOKING...OVR THE NRN BAJA REGION.
UPSTREAM OVR WA...WEAK SW ATOP OF RIDGE WHICH WILL ARRIVE OVR NERN
WY THIS EVE. UPR BUBBLE WILL LARGELY PROTECT THE FA AND POINTS
WEST...FOR NOW...FROM MOST PRECIP ACTIVITY...KEEPING LOW CHANCES FOR
POPS OVR THE ERN CWA TO THE HIGH/CNTRL PLAINS. SFC HAS GENERAL HIGH
P ACROSS THE FA...WITH LOW P AND AN ATTENDANT WEAK WARM FRONT FROM
ERN UT INTO WRN CO.

HOT AND DRY FOR THE MOST PART WITH AMPLIFIED PORTION OF THE RIDGE
AXIS CAPPING MOST OF THE FA...KEEPING SHOWERS AND STORMS AT A
MINIMUM...LARGELY RELEGATED ON AN ISOLATED BASIS TO A FEW OF THE
HIGHEST PEAKS...SUCH AS THE ABSAROKAS AND BIGHORNS LATE TODAY/THIS
EVE. ADDITIONALLY TODAY...LOW P OVR UT WILL ALLOW FOR A WEAK WARM
FRONT TO BUILD ACROSS THE WY/CO BORDER AREA...LIFTING ACROSS ERN WY
INTO FRI EVENING WITH SOME MODEST MOISTURE RETURNING TO ERN
WY...WITH SOME LOW CHCS FOR THUNDER BY THIS EVENING AS A SMALL SW
TROF ARRIVES OVERHEAD THRU THE RIDGE THIS EVENING. ATTM...DOES NOT
LOOK LIKE MUCH OF THIS MOISTURE WILL MAKE IT BACK INTO THE ERN
ZONES...BUT CASPER MOUNTAIN...AND TO A LESSER EXTENT THE REST OF
NATRONA OR JOHNSON COUNTY MAY SEE AN ISOLATED LATE DAY T-STORM.
SATURDAY WILL BE WITHOUT PRECIP EVERYWHERE AS DRY AIR ADVECTS FROM
THE WEST OVR THE FA AND ANY SIGNIFICANT MOISTURE IS HELD AT BAY TO
THE SOUTH. SUNDAY...HOTTEST DAY OF THE PERIOD...BUT WEAK MOISTURE
DOES START TO SLOWLY WORK ITS WAY TOWARD AND INTO THE FA THRU THE
DAY...ALLOWING FOR LOW CHANCE PRECIP ACROSS FAVORED MOUNTAIN RANGES
LATER SUNDAY EVENING AND OVERNIGHT PERIOD. THIS WILL BE A PRECURSOR
TO SOMEWHAT BETTER CHCS FOR PRECIP LATER MONDAY...AS THE UPR RIDGE
AXIS ROTATES CLOCKWISE AND CENTERS THRU THE CENTER OF WY...AND SOME
MODEST MONSOONAL TYPE MOISTURE STARTS TO FEED ACROSS THE
INTERMOUNTAIN WEST JUST AHEAD OF  WHAT WAS THE BAJA DISTURBANCE
DESCRIBED ABOVE.

.LONG TERM...MONDAY THROUGH FRIDAY

IT APPEARS THAT THE LONG RANGE MODELS ARE NOW LATCHING ON TO A
WEATHER SYSTEM ROTATING THROUGH THE GREAT BASIN MONDAY. A PORTION
OF THIS WAVE MOVES INTO WY MONDAY AFTERNOON AND THEN PROGRESSES
NORTHWARD THROUGH TUESDAY MORNING. CURRENT FORECAST FOR MONDAY
THROUGH TUESDAY MORNING REFLECTS A HIGHER PRECIP CHANCE IN SOME
AREAS AND DID NOT ALTER THAT FORECAST MUCH. A SOUTHWEST FLOW ALOFT
IS FORECAST TUE PM THROUGH FRIDAY. THIS IS DUE TO AN UPPER LEVEL
STORM SYSTEM THAT ROTATES OFF THE WEST COAST OF CANADA TUESDAY AND
THEN GRADUALLY SINKS SOUTH TO JUST OFF THE NW COAST OF THE U.S.
NEXT FRIDAY. IN THIS SW FLOW ALOFT A FEW WEATHER DISTURBANCES PASS
THROUGH WHICH WOULD BRING A LITTLE HIGHER CHANCE OF STORMS. TIMING
THESE THAT FAR OUT IS NOT EASY OR CONSISTENT. THE 00Z RUNS BRING
ONE DISTURBANCE THROUGH ON WEDNESDAY FOLLOWED BY ANOTHER THURS
NIGHT. I ADJUSTED SOME PRECIP CHANCES ON THOSE DAYS AND NIGHTS BUT
I EXPECT THE TIMING TO CHANGE IN THE COMING DAYS. AS FOR
TEMPS...MONDAY NOW LOOKS COOLER DUE TO MORE CLOUDS AND GREATER
COVERAGE OF SHOWERS OR STORMS. TUE THROUGH FRIDAY WILL BE WARM TO
LOCALLY HOT WITH 80S TO LOW 90S FOR MOST LOWER ELEVATIONS...WITH
UPPER 70S TO LOW 80S IN THE WESTERN VALLEYS. AS STATED
PREVIOUSLY...THE LIGHTNING THAT IS PRODUCED BY THE STORMS NEXT
WEEK WILL LIKELY START SOME FIRES IN PLACES WHERE THE FUELS ARE
RIPE FOR BURNING. THIS THREAT WILL CONTINUE TO BE ANALYZED OVER
THE COMING DAYS.

&&

.AVIATION.../18Z ISSUANCE/

VFR CONDITIONS STILL EXPECTED THROUGH 00Z SUNDAY WITH RELATIVELY
QUIET WEATHER PATTERN.  WITH LOW PRESSURE DEVELOPING OVER THE GREAT
BASIN OVERNIGHT AND HIGH PRESSURE SLIDING DOWN FROM MONTANA...WIND
WILL TURN NORTHERLY AND EASTERLY AFTER 06Z SATURDAY WITH SOME GUSTS
TO 20 KNOTS AROUND RKS AND HIGHER TERRAIN.  SOME WEAK CONVECTIVE
ACTIVITY POSSIBLE LATE THIS AFTERNOON INTO THE EVENING HOURS OVER
ABSAROKAS AND BIGHORN MOUNTAINS...WITH SLIGHT CHANCE OF IMPACT FROM
KBYG AND KCPR.  SATURDAY LOOKS A BIT DRIER WITH GENERALLY LIGHT WINDS
AS WELL.

&&

.FIRE WEATHER...

MINIMUM RH VALUES ARE EXPECTED TO REMAIN IN THE SINGLE DIGITS TO LOW
TEENS THROUGH THE WEEKEND ACROSS THE SOUTH AND LOW ELEVATION AREAS
EAST OF THE DIVIDE...WITH UPPER TEENS AND 20S OVER THE MOUNTAINS.
RELATIVE HUMIDITY WILL HAVE LITTLE TIME RECOVERING
OVERNIGHT...ESPECIALLY AT MID SLOPE WHERE RHS MAY NOT RISE OUT OF
THE MID 20S IN THE CENTRAL WYOMING RANGES. GENERALLY LIGHT WINDS ARE
EXPECTED THROUGH THE WEEKEND...WITH ONLY A FEW LIGHT BREEZES
POSSIBLE IN THE AFTERNOON AND EVENINGS ACROSS THE LOWER ELEVATIONS
OF CENTRAL AND SOUTHERN WYOMING. OTHERWISE...A VERY DRY ATMOSPHERE
WITH HIGH PRESSURE AT THE SURFACE AND ALOFT WILL KEEP MOST CHANCES
FOR ANY PRECIPITATION ISOLATED AND RELEGATED TO MAINLY A FEW
MOUNTAIN OR EASTERN ZONES LATER TODAY. LITTLE IF ANY CHANCE FOR
SHOWERS/STORMS WILL OCCUR ON SATURDAY AT ANY LOCATION. SUNDAY WILL
SEE THE WARMEST TEMPERATURES OF THE WEEKEND...HOWEVER MOISTURE WILL
SLOWLY ALSO BE INCREASING WITH ISOLATED THUNDERSTORM CHANCES
RETURNING LATER IN THE DAY AND OVERNIGHT...WITH WIDELY SCATTERED
CHANCES FOR PRECIPITATION BY MONDAY AFTERNOON.

&&

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

&&

$$

SHORT TERM...BRAUN
LONG TERM...AR
AVIATION...MCDONALD
FIRE WEATHER...BRAUN




000
FXUS63 KUNR 311726
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
1126 AM MDT FRI JUL 31 2015

.UPDATE...
ISSUED AT 1024 AM MDT FRI JUL 31 2015

BASED ON THE 12Z MODELS HAVE EXPANDED THE AREA WHERE
THUNDERSTORMS WILL BE POSSIBLE LATE THIS AFTERNOON AND THIS
EVENING. INSTABILITY REMAINS RATHER WEAK THIS AFTERNOON AND WITH
VERY LITTLE SHEAR OVER NERN WY AND THE BLKHLS AREA EXPECT ANY
THUNDERSTORMS THAT MAY DEVELOP TODAY TO REMAIN ISOLATED AND
SHORT IN DURATION. DUE TO DRY LOW LEVELS GUSTY SFC WINDS LOOK TO
BE THE MOST LIKELY RESULT OF ANY CONVECTION. MID LEVEL INSTABILITY
INCREASES TONIGHT POSSIBLY LEADING TO LONGER LASTING TSTMS EAST
OF THE BLKHLS MOVING EASTWARD TONIGHT ESP FROM SWRN INTO SC SD.

&&

.SHORT TERM...TODAY THROUGH SATURDAY NIGHT
ISSUED AT 236 AM MDT FRI JUL 31 2015

BROAD UPPER RIDGING WILL REMAIN ACROSS THE WRN CONUS THROUGH THE
REMAINDER OF THE WEEK. SURFACE HIGH PRESSURE WILL DOMINATE THE NRN
PLAINS TODAY BRINGING GENERALLY DRY WEATHER TO THE AREA.
TEMPERATURES WILL RISE INTO THE UPPER 80S TO MID 90S ACROSS THE
PLAINS...AND 80S OVER THE BLACK HILLS. WITH DEWPOINTS IN THE 40S TO
LOW 50S...THERE WONT BE MUCH MOISTURE/CAPE AVAILABLE FOR CONVECTION.
BUT CANT RULE OUT ISOLATED STORMS OVER THE HILLS INTO THE SRN PTNS
OF THE CWA MAINLY IN THE LATE AFTN/EVNG. OTHERWISE MOSTLY SUNNY
SKIES ARE EXPECTED AREAWIDE WITH RELATIVELY LIGHT WINDS. HIGH
PRESSURE WILL SLIDE EWD TONIGHT WITH RETURN FLOW SETTING UP ACROSS
NE WY/WRN SD. GOOD THETA E ADVECTION SET UP THE LOW/MID LEVELS WITH
STEEP LAPSE RATES. COULD SEE ELEVATED STORMS DEVELOP THROUGH THE
NIGHT...ESPECIALLY AS A SUBTLE UPPER WAVE AND WEAK COLD FRONT CROSS
THE AREA THROUGH EARLY SAT MRNG. BULK OF CONVECTION WILL BE EAST OF
THE CWA BY MID MORNING. WITH DRIER AIR RETURNING TO THE CWA...NOT
MUCH CONVECTION EXPECTED THROUGH THE DAY SATURDAY. HIGHS WILL BE IN
THE MID 80S TO MID 90S.

.LONG TERM...SUNDAY THROUGH THURSDAY
ISSUED AT 236 AM MDT FRI JUL 31 2015

GFS/ECMWF IN DECENT AGREEMENT WITH THE OVERALL PATTERN
FOR MUCH OF NEXT WEEK. HOWEVER...MINOR TIMING DIFFERENCES EXIST WITH
IMPULSES MOVING THROUGH THE NORTHERN PLAINS.

SUNDAY WILL BE WARM AND DRY AS UPPER RIDGE BUILDS ACROSS THE PLAINS.
HIGHS INTO THE 90S WITH RELATIVE HUMIDITY DROPPING TO AROUND 15
PERCENT. MIGHT BE SOME FIRE WEATHER CONCERNS...BUT WINDS LOOK
RELATIVELY LIGHT AT THIS TIME. THUNDERSTORM CHANCES INCREASE FOR THE
FIRST HALF OF THE WEEK. RIDGE BEGINS TO BREAK DOWN MONDAY AS IMPULSE
AND ASSOCIATED PLUME OF MID LEVEL MOISTURE LIFTS FROM THE DESERT
SOUTHWEST INTO THE ROCKIES. MAIN IMPULSE THEN LIFTS INTO THE
NORTHERN PLAINS TUESDAY. FOR THE LAST HALF OF THE WEEK...UPPER HIGH
REMAINS ANCHORED ACROSS THE SOUTHERN/CENTRAL PLAINS...WITH FLAT
RIDGE ACROSS THE NORTHERN PLAINS. SERIES OF SHORTWAVES RIDE OVER THE
RIDGE...WITH LOW LEVEL BAROCLINIC ZONE ACROSS THE AREA. THIS RESULTS
IS A DAILY CHANCE OF THUNDERSTORMS. TEMPERATURES WILL BE NEAR
AVERAGE.

&&

.AVIATION...FOR THE 18Z TAFS THROUGH 18Z SATURDAY
ISSUED AT 1125 AM MDT FRI JUL 31 2015

VFR CONDITIONS ARE GENERALLY EXPECTED THROUGH TONIGHT. ISOLATED
SHOWERS AND THUNDERSTORMS ARE POSSIBLE LATE THIS AFTERNOON AND
ESPECIALLY TONIGHT FROM NORTHEAST WY...THROUGH THE BLACK
HILLS...AND ACROSS SOUTHWEST SD.

&&

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

$$

UPDATE...WFO UNR
SHORT TERM...13
LONG TERM...7
AVIATION...26



000
FXUS63 KUNR 311726
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
1126 AM MDT FRI JUL 31 2015

.UPDATE...
ISSUED AT 1024 AM MDT FRI JUL 31 2015

BASED ON THE 12Z MODELS HAVE EXPANDED THE AREA WHERE
THUNDERSTORMS WILL BE POSSIBLE LATE THIS AFTERNOON AND THIS
EVENING. INSTABILITY REMAINS RATHER WEAK THIS AFTERNOON AND WITH
VERY LITTLE SHEAR OVER NERN WY AND THE BLKHLS AREA EXPECT ANY
THUNDERSTORMS THAT MAY DEVELOP TODAY TO REMAIN ISOLATED AND
SHORT IN DURATION. DUE TO DRY LOW LEVELS GUSTY SFC WINDS LOOK TO
BE THE MOST LIKELY RESULT OF ANY CONVECTION. MID LEVEL INSTABILITY
INCREASES TONIGHT POSSIBLY LEADING TO LONGER LASTING TSTMS EAST
OF THE BLKHLS MOVING EASTWARD TONIGHT ESP FROM SWRN INTO SC SD.

&&

.SHORT TERM...TODAY THROUGH SATURDAY NIGHT
ISSUED AT 236 AM MDT FRI JUL 31 2015

BROAD UPPER RIDGING WILL REMAIN ACROSS THE WRN CONUS THROUGH THE
REMAINDER OF THE WEEK. SURFACE HIGH PRESSURE WILL DOMINATE THE NRN
PLAINS TODAY BRINGING GENERALLY DRY WEATHER TO THE AREA.
TEMPERATURES WILL RISE INTO THE UPPER 80S TO MID 90S ACROSS THE
PLAINS...AND 80S OVER THE BLACK HILLS. WITH DEWPOINTS IN THE 40S TO
LOW 50S...THERE WONT BE MUCH MOISTURE/CAPE AVAILABLE FOR CONVECTION.
BUT CANT RULE OUT ISOLATED STORMS OVER THE HILLS INTO THE SRN PTNS
OF THE CWA MAINLY IN THE LATE AFTN/EVNG. OTHERWISE MOSTLY SUNNY
SKIES ARE EXPECTED AREAWIDE WITH RELATIVELY LIGHT WINDS. HIGH
PRESSURE WILL SLIDE EWD TONIGHT WITH RETURN FLOW SETTING UP ACROSS
NE WY/WRN SD. GOOD THETA E ADVECTION SET UP THE LOW/MID LEVELS WITH
STEEP LAPSE RATES. COULD SEE ELEVATED STORMS DEVELOP THROUGH THE
NIGHT...ESPECIALLY AS A SUBTLE UPPER WAVE AND WEAK COLD FRONT CROSS
THE AREA THROUGH EARLY SAT MRNG. BULK OF CONVECTION WILL BE EAST OF
THE CWA BY MID MORNING. WITH DRIER AIR RETURNING TO THE CWA...NOT
MUCH CONVECTION EXPECTED THROUGH THE DAY SATURDAY. HIGHS WILL BE IN
THE MID 80S TO MID 90S.

.LONG TERM...SUNDAY THROUGH THURSDAY
ISSUED AT 236 AM MDT FRI JUL 31 2015

GFS/ECMWF IN DECENT AGREEMENT WITH THE OVERALL PATTERN
FOR MUCH OF NEXT WEEK. HOWEVER...MINOR TIMING DIFFERENCES EXIST WITH
IMPULSES MOVING THROUGH THE NORTHERN PLAINS.

SUNDAY WILL BE WARM AND DRY AS UPPER RIDGE BUILDS ACROSS THE PLAINS.
HIGHS INTO THE 90S WITH RELATIVE HUMIDITY DROPPING TO AROUND 15
PERCENT. MIGHT BE SOME FIRE WEATHER CONCERNS...BUT WINDS LOOK
RELATIVELY LIGHT AT THIS TIME. THUNDERSTORM CHANCES INCREASE FOR THE
FIRST HALF OF THE WEEK. RIDGE BEGINS TO BREAK DOWN MONDAY AS IMPULSE
AND ASSOCIATED PLUME OF MID LEVEL MOISTURE LIFTS FROM THE DESERT
SOUTHWEST INTO THE ROCKIES. MAIN IMPULSE THEN LIFTS INTO THE
NORTHERN PLAINS TUESDAY. FOR THE LAST HALF OF THE WEEK...UPPER HIGH
REMAINS ANCHORED ACROSS THE SOUTHERN/CENTRAL PLAINS...WITH FLAT
RIDGE ACROSS THE NORTHERN PLAINS. SERIES OF SHORTWAVES RIDE OVER THE
RIDGE...WITH LOW LEVEL BAROCLINIC ZONE ACROSS THE AREA. THIS RESULTS
IS A DAILY CHANCE OF THUNDERSTORMS. TEMPERATURES WILL BE NEAR
AVERAGE.

&&

.AVIATION...FOR THE 18Z TAFS THROUGH 18Z SATURDAY
ISSUED AT 1125 AM MDT FRI JUL 31 2015

VFR CONDITIONS ARE GENERALLY EXPECTED THROUGH TONIGHT. ISOLATED
SHOWERS AND THUNDERSTORMS ARE POSSIBLE LATE THIS AFTERNOON AND
ESPECIALLY TONIGHT FROM NORTHEAST WY...THROUGH THE BLACK
HILLS...AND ACROSS SOUTHWEST SD.

&&

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

$$

UPDATE...WFO UNR
SHORT TERM...13
LONG TERM...7
AVIATION...26




000
FXUS63 KUNR 311642
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
1042 AM MDT FRI JUL 31 2015

.UPDATE...
ISSUED AT 1024 AM MDT FRI JUL 31 2015

BASED ON THE 12Z MODELS HAVE EXPANDED THE AREA WHERE
THUNDERSTORMS WILL BE POSSIBLE LATE THIS AFTERNOON AND THIS
EVENING. INSTABILITY REMAINS RATHER WEAK THIS AFTERNOON AND WITH
VERY LITTLE SHEAR OVER NERN WY AND THE BLKHLS AREA EXPECT ANY
THUNDERSTORMS THAT MAY DEVELOP TODAY TO REMAIN ISOLATED AND
SHORT IN DURATION. DUE TO DRY LOW LEVELS GUSTY SFC WINDS LOOK TO
BE THE MOST LIKELY RESULT OF ANY CONVECTION. MID LEVEL INSTABILITY
INCREASES TONIGHT POSSIBLY LEADING TO LONGER LASTING TSTMS EAST
OF THE BLKHLS MOVING EASTWARD TONIGHT ESP FROM SWRN INTO SC SD.

&&

.SHORT TERM...TODAY THROUGH SATURDAY NIGHT
ISSUED AT 236 AM MDT FRI JUL 31 2015

BROAD UPPER RIDGING WILL REMAIN ACROSS THE WRN CONUS THROUGH THE
REMAINDER OF THE WEEK. SURFACE HIGH PRESSURE WILL DOMINATE THE NRN
PLAINS TODAY BRINGING GENERALLY DRY WEATHER TO THE AREA.
TEMPERATURES WILL RISE INTO THE UPPER 80S TO MID 90S ACROSS THE
PLAINS...AND 80S OVER THE BLACK HILLS. WITH DEWPOINTS IN THE 40S TO
LOW 50S...THERE WONT BE MUCH MOISTURE/CAPE AVAILABLE FOR CONVECTION.
BUT CANT RULE OUT ISOLATED STORMS OVER THE HILLS INTO THE SRN PTNS
OF THE CWA MAINLY IN THE LATE AFTN/EVNG. OTHERWISE MOSTLY SUNNY
SKIES ARE EXPECTED AREAWIDE WITH RELATIVELY LIGHT WINDS. HIGH
PRESSURE WILL SLIDE EWD TONIGHT WITH RETURN FLOW SETTING UP ACROSS
NE WY/WRN SD. GOOD THETA E ADVECTION SET UP THE LOW/MID LEVELS WITH
STEEP LAPSE RATES. COULD SEE ELEVATED STORMS DEVELOP THROUGH THE
NIGHT...ESPECIALLY AS A SUBTLE UPPER WAVE AND WEAK COLD FRONT CROSS
THE AREA THROUGH EARLY SAT MRNG. BULK OF CONVECTION WILL BE EAST OF
THE CWA BY MID MORNING. WITH DRIER AIR RETURNING TO THE CWA...NOT
MUCH CONVECTION EXPECTED THROUGH THE DAY SATURDAY. HIGHS WILL BE IN
THE MID 80S TO MID 90S.

.LONG TERM...SUNDAY THROUGH THURSDAY
ISSUED AT 236 AM MDT FRI JUL 31 2015

GFS/ECMWF IN DECENT AGREEMENT WITH THE OVERALL PATTERN
FOR MUCH OF NEXT WEEK. HOWEVER...MINOR TIMING DIFFERENCES EXIST WITH
IMPULSES MOVING THROUGH THE NORTHERN PLAINS.

SUNDAY WILL BE WARM AND DRY AS UPPER RIDGE BUILDS ACROSS THE PLAINS.
HIGHS INTO THE 90S WITH RELATIVE HUMIDITY DROPPING TO AROUND 15
PERCENT. MIGHT BE SOME FIRE WEATHER CONCERNS...BUT WINDS LOOK
RELATIVELY LIGHT AT THIS TIME. THUNDERSTORM CHANCES INCREASE FOR THE
FIRST HALF OF THE WEEK. RIDGE BEGINS TO BREAK DOWN MONDAY AS IMPULSE
AND ASSOCIATED PLUME OF MID LEVEL MOISTURE LIFTS FROM THE DESERT
SOUTHWEST INTO THE ROCKIES. MAIN IMPULSE THEN LIFTS INTO THE
NORTHERN PLAINS TUESDAY. FOR THE LAST HALF OF THE WEEK...UPPER HIGH
REMAINS ANCHORED ACROSS THE SOUTHERN/CENTRAL PLAINS...WITH FLAT
RIDGE ACROSS THE NORTHERN PLAINS. SERIES OF SHORTWAVES RIDE OVER THE
RIDGE...WITH LOW LEVEL BAROCLINIC ZONE ACROSS THE AREA. THIS RESULTS
IS A DAILY CHANCE OF THUNDERSTORMS. TEMPERATURES WILL BE NEAR
AVERAGE.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 508 AM MDT FRI JUL 31 2015

VFR CONDITIONS EXPECTED THROUGH TONIGHT.


&&

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

$$

UPDATE...WFO UNR
SHORT TERM...13
LONG TERM...7
AVIATION...7



000
FXUS63 KUNR 311642
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
1042 AM MDT FRI JUL 31 2015

.UPDATE...
ISSUED AT 1024 AM MDT FRI JUL 31 2015

BASED ON THE 12Z MODELS HAVE EXPANDED THE AREA WHERE
THUNDERSTORMS WILL BE POSSIBLE LATE THIS AFTERNOON AND THIS
EVENING. INSTABILITY REMAINS RATHER WEAK THIS AFTERNOON AND WITH
VERY LITTLE SHEAR OVER NERN WY AND THE BLKHLS AREA EXPECT ANY
THUNDERSTORMS THAT MAY DEVELOP TODAY TO REMAIN ISOLATED AND
SHORT IN DURATION. DUE TO DRY LOW LEVELS GUSTY SFC WINDS LOOK TO
BE THE MOST LIKELY RESULT OF ANY CONVECTION. MID LEVEL INSTABILITY
INCREASES TONIGHT POSSIBLY LEADING TO LONGER LASTING TSTMS EAST
OF THE BLKHLS MOVING EASTWARD TONIGHT ESP FROM SWRN INTO SC SD.

&&

.SHORT TERM...TODAY THROUGH SATURDAY NIGHT
ISSUED AT 236 AM MDT FRI JUL 31 2015

BROAD UPPER RIDGING WILL REMAIN ACROSS THE WRN CONUS THROUGH THE
REMAINDER OF THE WEEK. SURFACE HIGH PRESSURE WILL DOMINATE THE NRN
PLAINS TODAY BRINGING GENERALLY DRY WEATHER TO THE AREA.
TEMPERATURES WILL RISE INTO THE UPPER 80S TO MID 90S ACROSS THE
PLAINS...AND 80S OVER THE BLACK HILLS. WITH DEWPOINTS IN THE 40S TO
LOW 50S...THERE WONT BE MUCH MOISTURE/CAPE AVAILABLE FOR CONVECTION.
BUT CANT RULE OUT ISOLATED STORMS OVER THE HILLS INTO THE SRN PTNS
OF THE CWA MAINLY IN THE LATE AFTN/EVNG. OTHERWISE MOSTLY SUNNY
SKIES ARE EXPECTED AREAWIDE WITH RELATIVELY LIGHT WINDS. HIGH
PRESSURE WILL SLIDE EWD TONIGHT WITH RETURN FLOW SETTING UP ACROSS
NE WY/WRN SD. GOOD THETA E ADVECTION SET UP THE LOW/MID LEVELS WITH
STEEP LAPSE RATES. COULD SEE ELEVATED STORMS DEVELOP THROUGH THE
NIGHT...ESPECIALLY AS A SUBTLE UPPER WAVE AND WEAK COLD FRONT CROSS
THE AREA THROUGH EARLY SAT MRNG. BULK OF CONVECTION WILL BE EAST OF
THE CWA BY MID MORNING. WITH DRIER AIR RETURNING TO THE CWA...NOT
MUCH CONVECTION EXPECTED THROUGH THE DAY SATURDAY. HIGHS WILL BE IN
THE MID 80S TO MID 90S.

.LONG TERM...SUNDAY THROUGH THURSDAY
ISSUED AT 236 AM MDT FRI JUL 31 2015

GFS/ECMWF IN DECENT AGREEMENT WITH THE OVERALL PATTERN
FOR MUCH OF NEXT WEEK. HOWEVER...MINOR TIMING DIFFERENCES EXIST WITH
IMPULSES MOVING THROUGH THE NORTHERN PLAINS.

SUNDAY WILL BE WARM AND DRY AS UPPER RIDGE BUILDS ACROSS THE PLAINS.
HIGHS INTO THE 90S WITH RELATIVE HUMIDITY DROPPING TO AROUND 15
PERCENT. MIGHT BE SOME FIRE WEATHER CONCERNS...BUT WINDS LOOK
RELATIVELY LIGHT AT THIS TIME. THUNDERSTORM CHANCES INCREASE FOR THE
FIRST HALF OF THE WEEK. RIDGE BEGINS TO BREAK DOWN MONDAY AS IMPULSE
AND ASSOCIATED PLUME OF MID LEVEL MOISTURE LIFTS FROM THE DESERT
SOUTHWEST INTO THE ROCKIES. MAIN IMPULSE THEN LIFTS INTO THE
NORTHERN PLAINS TUESDAY. FOR THE LAST HALF OF THE WEEK...UPPER HIGH
REMAINS ANCHORED ACROSS THE SOUTHERN/CENTRAL PLAINS...WITH FLAT
RIDGE ACROSS THE NORTHERN PLAINS. SERIES OF SHORTWAVES RIDE OVER THE
RIDGE...WITH LOW LEVEL BAROCLINIC ZONE ACROSS THE AREA. THIS RESULTS
IS A DAILY CHANCE OF THUNDERSTORMS. TEMPERATURES WILL BE NEAR
AVERAGE.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 508 AM MDT FRI JUL 31 2015

VFR CONDITIONS EXPECTED THROUGH TONIGHT.


&&

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

$$

UPDATE...WFO UNR
SHORT TERM...13
LONG TERM...7
AVIATION...7




000
FXUS65 KCYS 311116
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
516 AM MDT FRI JUL 31 2015

.SHORT TERM...(TODAY AND SUNDAY NIGHT)
ISSUED AT 300 AM MDT FRI JUL 31 2015

TODAY...FLOW ALOFT IS NORTHWEST. INCREASED LOW LEVEL MOISTURE FROM
24 HOURS AGO. DECENT 850/700 MB THETA-E RIDGE AXIS ACROSS SOUTHEAST
WYOMING WITH LOW LEVEL POSITIVE THETA-E ADVECTION...THUS AGREE WITH
THE NAM DEPICTION OF ISOLATED AFTERNOON THUNDERSTORMS ALONG AND EAST
OF INTERSTATE 25.

TONIGHT...THUNDERSTORMS WILL DIE OFF WITH LOSS OF DAYTIME HEATING IN
THE ABSENCE OF UPPER LEVEL ENERGY.

SATURDAY...LOW AND MID LEVEL WINDS SWITCH TO A NORTH DIRECTION WITH
DRIER AND MORE STABLE AIRMASS IN PLACE...THOUGH STILL ENOUGH
INSTABILITY FOR A SLIGHT CHANCE OF AFTERNOON THUNDERSTORMS MAINLY
ACROSS WESTERN NEBRASKA.

SATURDAY NIGHT/SUNDAY/SUNDAY NIGHT...FLOW ALOFT REMAINS NORTHWEST.
LOW AND MID LEVEL THETA-E RIDGE AXIS WILL LIE JUST SOUTH OF THE
COLORADO STATE LINE AND THERE WILL BE ENOUGH POSITIVE THETA-E
ADVECTION FOR ISOLATED THUNDERSTORMS JUST NORTH OF THE STATE LINE IN
THE AFTERNOON...THEN STORMS ENDING IN THE EVENING WITH LOSS OF
DAYTIME HEATING.

.LONG TERM...(MONDAY THROUGH THURSDAY)
ISSUED AT 300 AM MDT FRI JUL 31 2015

RIDGE AXIS STILL FORECAST TO DRIFT OFF TO THE EAST OF THE CHEYENNE
CWFA MONDAY ALLOWING MONSOONAL MOISTURE TO DRIFT NORTH INTO THE
AREA. SHORTWAVE ENERGY MONDAY NIGHT INTO TUESDAY MORNING MOVES
THROUGH THE AREA. BOTH THE GFS AND ECMWF SHOW THIS HAPPENING.
ECMWF MORE BULLISH ON QPF WHILE GFS KEEP MOST RAINFALL SOUTH IN
COLORADO. FOLLOWED THE ECMWF SOLUTION IN OUR FORECAST AND RAISED
POPS OVER GUIDANCE MONDAY AFTERNOON AND EVENING.

NEED TO BE WATCHING TUESDAY AND WEDNESDAY AS WE COULD BE LOOKING
AT SEVERE THUNDERSTORMS. HAVE A 60KT JET MOVING OVER THE AREA THAT
WILL INTERACT WITH A STALLED OUT FRONTAL BOUNDARY EAST OF THE
LARAMIE RANGE. GFS HAS JET FURTHER NORTH THAN THE ECMWF. WEATHER
DEFINITELY MORE UNSETTLED THROUGH MUCH OF NEXT WEEK.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 513 AM MDT FRI JUL 31 2015

HRRR USED FOR TIMING OF CONVECTION ALONG THE I-80 CORRIDOR THIS
AFTERNOON. HAS CONVECTION DEVELOPING ACROSS THE SOUTH LARAMIE
RANGE AND NORTHERN COLORADO...DRIFTING NORTHEAST INTO THE PLAINS
AFTER 22Z OR SO. CONTINUED VCTS WORDING FOR KCYS...KLAR AND KSNY.

&&

.FIRE WEATHER...
ISSUED AT 152 AM MDT FRI JUL 31 2015

LOW AFTERNOON RELATIVE HUMIDITIES AGAIN IN THE
AFTERNOON WEST OF INTERSTATE 25 THE NEXT FEW DAYS...THOUGH
FORTUNATELY WINDS WILL BE RELATIVELY LIGHT.

&&

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

$$

SHORT TERM...RUBIN
LONG TERM...GCC
AVIATION...GCC
FIRE WEATHER...RUBIN



000
FXUS65 KCYS 311116
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
516 AM MDT FRI JUL 31 2015

.SHORT TERM...(TODAY AND SUNDAY NIGHT)
ISSUED AT 300 AM MDT FRI JUL 31 2015

TODAY...FLOW ALOFT IS NORTHWEST. INCREASED LOW LEVEL MOISTURE FROM
24 HOURS AGO. DECENT 850/700 MB THETA-E RIDGE AXIS ACROSS SOUTHEAST
WYOMING WITH LOW LEVEL POSITIVE THETA-E ADVECTION...THUS AGREE WITH
THE NAM DEPICTION OF ISOLATED AFTERNOON THUNDERSTORMS ALONG AND EAST
OF INTERSTATE 25.

TONIGHT...THUNDERSTORMS WILL DIE OFF WITH LOSS OF DAYTIME HEATING IN
THE ABSENCE OF UPPER LEVEL ENERGY.

SATURDAY...LOW AND MID LEVEL WINDS SWITCH TO A NORTH DIRECTION WITH
DRIER AND MORE STABLE AIRMASS IN PLACE...THOUGH STILL ENOUGH
INSTABILITY FOR A SLIGHT CHANCE OF AFTERNOON THUNDERSTORMS MAINLY
ACROSS WESTERN NEBRASKA.

SATURDAY NIGHT/SUNDAY/SUNDAY NIGHT...FLOW ALOFT REMAINS NORTHWEST.
LOW AND MID LEVEL THETA-E RIDGE AXIS WILL LIE JUST SOUTH OF THE
COLORADO STATE LINE AND THERE WILL BE ENOUGH POSITIVE THETA-E
ADVECTION FOR ISOLATED THUNDERSTORMS JUST NORTH OF THE STATE LINE IN
THE AFTERNOON...THEN STORMS ENDING IN THE EVENING WITH LOSS OF
DAYTIME HEATING.

.LONG TERM...(MONDAY THROUGH THURSDAY)
ISSUED AT 300 AM MDT FRI JUL 31 2015

RIDGE AXIS STILL FORECAST TO DRIFT OFF TO THE EAST OF THE CHEYENNE
CWFA MONDAY ALLOWING MONSOONAL MOISTURE TO DRIFT NORTH INTO THE
AREA. SHORTWAVE ENERGY MONDAY NIGHT INTO TUESDAY MORNING MOVES
THROUGH THE AREA. BOTH THE GFS AND ECMWF SHOW THIS HAPPENING.
ECMWF MORE BULLISH ON QPF WHILE GFS KEEP MOST RAINFALL SOUTH IN
COLORADO. FOLLOWED THE ECMWF SOLUTION IN OUR FORECAST AND RAISED
POPS OVER GUIDANCE MONDAY AFTERNOON AND EVENING.

NEED TO BE WATCHING TUESDAY AND WEDNESDAY AS WE COULD BE LOOKING
AT SEVERE THUNDERSTORMS. HAVE A 60KT JET MOVING OVER THE AREA THAT
WILL INTERACT WITH A STALLED OUT FRONTAL BOUNDARY EAST OF THE
LARAMIE RANGE. GFS HAS JET FURTHER NORTH THAN THE ECMWF. WEATHER
DEFINITELY MORE UNSETTLED THROUGH MUCH OF NEXT WEEK.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 513 AM MDT FRI JUL 31 2015

HRRR USED FOR TIMING OF CONVECTION ALONG THE I-80 CORRIDOR THIS
AFTERNOON. HAS CONVECTION DEVELOPING ACROSS THE SOUTH LARAMIE
RANGE AND NORTHERN COLORADO...DRIFTING NORTHEAST INTO THE PLAINS
AFTER 22Z OR SO. CONTINUED VCTS WORDING FOR KCYS...KLAR AND KSNY.

&&

.FIRE WEATHER...
ISSUED AT 152 AM MDT FRI JUL 31 2015

LOW AFTERNOON RELATIVE HUMIDITIES AGAIN IN THE
AFTERNOON WEST OF INTERSTATE 25 THE NEXT FEW DAYS...THOUGH
FORTUNATELY WINDS WILL BE RELATIVELY LIGHT.

&&

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

$$

SHORT TERM...RUBIN
LONG TERM...GCC
AVIATION...GCC
FIRE WEATHER...RUBIN




000
FXUS65 KCYS 311116
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
516 AM MDT FRI JUL 31 2015

.SHORT TERM...(TODAY AND SUNDAY NIGHT)
ISSUED AT 300 AM MDT FRI JUL 31 2015

TODAY...FLOW ALOFT IS NORTHWEST. INCREASED LOW LEVEL MOISTURE FROM
24 HOURS AGO. DECENT 850/700 MB THETA-E RIDGE AXIS ACROSS SOUTHEAST
WYOMING WITH LOW LEVEL POSITIVE THETA-E ADVECTION...THUS AGREE WITH
THE NAM DEPICTION OF ISOLATED AFTERNOON THUNDERSTORMS ALONG AND EAST
OF INTERSTATE 25.

TONIGHT...THUNDERSTORMS WILL DIE OFF WITH LOSS OF DAYTIME HEATING IN
THE ABSENCE OF UPPER LEVEL ENERGY.

SATURDAY...LOW AND MID LEVEL WINDS SWITCH TO A NORTH DIRECTION WITH
DRIER AND MORE STABLE AIRMASS IN PLACE...THOUGH STILL ENOUGH
INSTABILITY FOR A SLIGHT CHANCE OF AFTERNOON THUNDERSTORMS MAINLY
ACROSS WESTERN NEBRASKA.

SATURDAY NIGHT/SUNDAY/SUNDAY NIGHT...FLOW ALOFT REMAINS NORTHWEST.
LOW AND MID LEVEL THETA-E RIDGE AXIS WILL LIE JUST SOUTH OF THE
COLORADO STATE LINE AND THERE WILL BE ENOUGH POSITIVE THETA-E
ADVECTION FOR ISOLATED THUNDERSTORMS JUST NORTH OF THE STATE LINE IN
THE AFTERNOON...THEN STORMS ENDING IN THE EVENING WITH LOSS OF
DAYTIME HEATING.

.LONG TERM...(MONDAY THROUGH THURSDAY)
ISSUED AT 300 AM MDT FRI JUL 31 2015

RIDGE AXIS STILL FORECAST TO DRIFT OFF TO THE EAST OF THE CHEYENNE
CWFA MONDAY ALLOWING MONSOONAL MOISTURE TO DRIFT NORTH INTO THE
AREA. SHORTWAVE ENERGY MONDAY NIGHT INTO TUESDAY MORNING MOVES
THROUGH THE AREA. BOTH THE GFS AND ECMWF SHOW THIS HAPPENING.
ECMWF MORE BULLISH ON QPF WHILE GFS KEEP MOST RAINFALL SOUTH IN
COLORADO. FOLLOWED THE ECMWF SOLUTION IN OUR FORECAST AND RAISED
POPS OVER GUIDANCE MONDAY AFTERNOON AND EVENING.

NEED TO BE WATCHING TUESDAY AND WEDNESDAY AS WE COULD BE LOOKING
AT SEVERE THUNDERSTORMS. HAVE A 60KT JET MOVING OVER THE AREA THAT
WILL INTERACT WITH A STALLED OUT FRONTAL BOUNDARY EAST OF THE
LARAMIE RANGE. GFS HAS JET FURTHER NORTH THAN THE ECMWF. WEATHER
DEFINITELY MORE UNSETTLED THROUGH MUCH OF NEXT WEEK.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 513 AM MDT FRI JUL 31 2015

HRRR USED FOR TIMING OF CONVECTION ALONG THE I-80 CORRIDOR THIS
AFTERNOON. HAS CONVECTION DEVELOPING ACROSS THE SOUTH LARAMIE
RANGE AND NORTHERN COLORADO...DRIFTING NORTHEAST INTO THE PLAINS
AFTER 22Z OR SO. CONTINUED VCTS WORDING FOR KCYS...KLAR AND KSNY.

&&

.FIRE WEATHER...
ISSUED AT 152 AM MDT FRI JUL 31 2015

LOW AFTERNOON RELATIVE HUMIDITIES AGAIN IN THE
AFTERNOON WEST OF INTERSTATE 25 THE NEXT FEW DAYS...THOUGH
FORTUNATELY WINDS WILL BE RELATIVELY LIGHT.

&&

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

$$

SHORT TERM...RUBIN
LONG TERM...GCC
AVIATION...GCC
FIRE WEATHER...RUBIN




000
FXUS65 KCYS 311116
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
516 AM MDT FRI JUL 31 2015

.SHORT TERM...(TODAY AND SUNDAY NIGHT)
ISSUED AT 300 AM MDT FRI JUL 31 2015

TODAY...FLOW ALOFT IS NORTHWEST. INCREASED LOW LEVEL MOISTURE FROM
24 HOURS AGO. DECENT 850/700 MB THETA-E RIDGE AXIS ACROSS SOUTHEAST
WYOMING WITH LOW LEVEL POSITIVE THETA-E ADVECTION...THUS AGREE WITH
THE NAM DEPICTION OF ISOLATED AFTERNOON THUNDERSTORMS ALONG AND EAST
OF INTERSTATE 25.

TONIGHT...THUNDERSTORMS WILL DIE OFF WITH LOSS OF DAYTIME HEATING IN
THE ABSENCE OF UPPER LEVEL ENERGY.

SATURDAY...LOW AND MID LEVEL WINDS SWITCH TO A NORTH DIRECTION WITH
DRIER AND MORE STABLE AIRMASS IN PLACE...THOUGH STILL ENOUGH
INSTABILITY FOR A SLIGHT CHANCE OF AFTERNOON THUNDERSTORMS MAINLY
ACROSS WESTERN NEBRASKA.

SATURDAY NIGHT/SUNDAY/SUNDAY NIGHT...FLOW ALOFT REMAINS NORTHWEST.
LOW AND MID LEVEL THETA-E RIDGE AXIS WILL LIE JUST SOUTH OF THE
COLORADO STATE LINE AND THERE WILL BE ENOUGH POSITIVE THETA-E
ADVECTION FOR ISOLATED THUNDERSTORMS JUST NORTH OF THE STATE LINE IN
THE AFTERNOON...THEN STORMS ENDING IN THE EVENING WITH LOSS OF
DAYTIME HEATING.

.LONG TERM...(MONDAY THROUGH THURSDAY)
ISSUED AT 300 AM MDT FRI JUL 31 2015

RIDGE AXIS STILL FORECAST TO DRIFT OFF TO THE EAST OF THE CHEYENNE
CWFA MONDAY ALLOWING MONSOONAL MOISTURE TO DRIFT NORTH INTO THE
AREA. SHORTWAVE ENERGY MONDAY NIGHT INTO TUESDAY MORNING MOVES
THROUGH THE AREA. BOTH THE GFS AND ECMWF SHOW THIS HAPPENING.
ECMWF MORE BULLISH ON QPF WHILE GFS KEEP MOST RAINFALL SOUTH IN
COLORADO. FOLLOWED THE ECMWF SOLUTION IN OUR FORECAST AND RAISED
POPS OVER GUIDANCE MONDAY AFTERNOON AND EVENING.

NEED TO BE WATCHING TUESDAY AND WEDNESDAY AS WE COULD BE LOOKING
AT SEVERE THUNDERSTORMS. HAVE A 60KT JET MOVING OVER THE AREA THAT
WILL INTERACT WITH A STALLED OUT FRONTAL BOUNDARY EAST OF THE
LARAMIE RANGE. GFS HAS JET FURTHER NORTH THAN THE ECMWF. WEATHER
DEFINITELY MORE UNSETTLED THROUGH MUCH OF NEXT WEEK.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 513 AM MDT FRI JUL 31 2015

HRRR USED FOR TIMING OF CONVECTION ALONG THE I-80 CORRIDOR THIS
AFTERNOON. HAS CONVECTION DEVELOPING ACROSS THE SOUTH LARAMIE
RANGE AND NORTHERN COLORADO...DRIFTING NORTHEAST INTO THE PLAINS
AFTER 22Z OR SO. CONTINUED VCTS WORDING FOR KCYS...KLAR AND KSNY.

&&

.FIRE WEATHER...
ISSUED AT 152 AM MDT FRI JUL 31 2015

LOW AFTERNOON RELATIVE HUMIDITIES AGAIN IN THE
AFTERNOON WEST OF INTERSTATE 25 THE NEXT FEW DAYS...THOUGH
FORTUNATELY WINDS WILL BE RELATIVELY LIGHT.

&&

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

$$

SHORT TERM...RUBIN
LONG TERM...GCC
AVIATION...GCC
FIRE WEATHER...RUBIN




000
FXUS65 KCYS 311116
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
516 AM MDT FRI JUL 31 2015

.SHORT TERM...(TODAY AND SUNDAY NIGHT)
ISSUED AT 300 AM MDT FRI JUL 31 2015

TODAY...FLOW ALOFT IS NORTHWEST. INCREASED LOW LEVEL MOISTURE FROM
24 HOURS AGO. DECENT 850/700 MB THETA-E RIDGE AXIS ACROSS SOUTHEAST
WYOMING WITH LOW LEVEL POSITIVE THETA-E ADVECTION...THUS AGREE WITH
THE NAM DEPICTION OF ISOLATED AFTERNOON THUNDERSTORMS ALONG AND EAST
OF INTERSTATE 25.

TONIGHT...THUNDERSTORMS WILL DIE OFF WITH LOSS OF DAYTIME HEATING IN
THE ABSENCE OF UPPER LEVEL ENERGY.

SATURDAY...LOW AND MID LEVEL WINDS SWITCH TO A NORTH DIRECTION WITH
DRIER AND MORE STABLE AIRMASS IN PLACE...THOUGH STILL ENOUGH
INSTABILITY FOR A SLIGHT CHANCE OF AFTERNOON THUNDERSTORMS MAINLY
ACROSS WESTERN NEBRASKA.

SATURDAY NIGHT/SUNDAY/SUNDAY NIGHT...FLOW ALOFT REMAINS NORTHWEST.
LOW AND MID LEVEL THETA-E RIDGE AXIS WILL LIE JUST SOUTH OF THE
COLORADO STATE LINE AND THERE WILL BE ENOUGH POSITIVE THETA-E
ADVECTION FOR ISOLATED THUNDERSTORMS JUST NORTH OF THE STATE LINE IN
THE AFTERNOON...THEN STORMS ENDING IN THE EVENING WITH LOSS OF
DAYTIME HEATING.

.LONG TERM...(MONDAY THROUGH THURSDAY)
ISSUED AT 300 AM MDT FRI JUL 31 2015

RIDGE AXIS STILL FORECAST TO DRIFT OFF TO THE EAST OF THE CHEYENNE
CWFA MONDAY ALLOWING MONSOONAL MOISTURE TO DRIFT NORTH INTO THE
AREA. SHORTWAVE ENERGY MONDAY NIGHT INTO TUESDAY MORNING MOVES
THROUGH THE AREA. BOTH THE GFS AND ECMWF SHOW THIS HAPPENING.
ECMWF MORE BULLISH ON QPF WHILE GFS KEEP MOST RAINFALL SOUTH IN
COLORADO. FOLLOWED THE ECMWF SOLUTION IN OUR FORECAST AND RAISED
POPS OVER GUIDANCE MONDAY AFTERNOON AND EVENING.

NEED TO BE WATCHING TUESDAY AND WEDNESDAY AS WE COULD BE LOOKING
AT SEVERE THUNDERSTORMS. HAVE A 60KT JET MOVING OVER THE AREA THAT
WILL INTERACT WITH A STALLED OUT FRONTAL BOUNDARY EAST OF THE
LARAMIE RANGE. GFS HAS JET FURTHER NORTH THAN THE ECMWF. WEATHER
DEFINITELY MORE UNSETTLED THROUGH MUCH OF NEXT WEEK.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 513 AM MDT FRI JUL 31 2015

HRRR USED FOR TIMING OF CONVECTION ALONG THE I-80 CORRIDOR THIS
AFTERNOON. HAS CONVECTION DEVELOPING ACROSS THE SOUTH LARAMIE
RANGE AND NORTHERN COLORADO...DRIFTING NORTHEAST INTO THE PLAINS
AFTER 22Z OR SO. CONTINUED VCTS WORDING FOR KCYS...KLAR AND KSNY.

&&

.FIRE WEATHER...
ISSUED AT 152 AM MDT FRI JUL 31 2015

LOW AFTERNOON RELATIVE HUMIDITIES AGAIN IN THE
AFTERNOON WEST OF INTERSTATE 25 THE NEXT FEW DAYS...THOUGH
FORTUNATELY WINDS WILL BE RELATIVELY LIGHT.

&&

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

$$

SHORT TERM...RUBIN
LONG TERM...GCC
AVIATION...GCC
FIRE WEATHER...RUBIN




000
FXUS65 KCYS 311116
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
516 AM MDT FRI JUL 31 2015

.SHORT TERM...(TODAY AND SUNDAY NIGHT)
ISSUED AT 300 AM MDT FRI JUL 31 2015

TODAY...FLOW ALOFT IS NORTHWEST. INCREASED LOW LEVEL MOISTURE FROM
24 HOURS AGO. DECENT 850/700 MB THETA-E RIDGE AXIS ACROSS SOUTHEAST
WYOMING WITH LOW LEVEL POSITIVE THETA-E ADVECTION...THUS AGREE WITH
THE NAM DEPICTION OF ISOLATED AFTERNOON THUNDERSTORMS ALONG AND EAST
OF INTERSTATE 25.

TONIGHT...THUNDERSTORMS WILL DIE OFF WITH LOSS OF DAYTIME HEATING IN
THE ABSENCE OF UPPER LEVEL ENERGY.

SATURDAY...LOW AND MID LEVEL WINDS SWITCH TO A NORTH DIRECTION WITH
DRIER AND MORE STABLE AIRMASS IN PLACE...THOUGH STILL ENOUGH
INSTABILITY FOR A SLIGHT CHANCE OF AFTERNOON THUNDERSTORMS MAINLY
ACROSS WESTERN NEBRASKA.

SATURDAY NIGHT/SUNDAY/SUNDAY NIGHT...FLOW ALOFT REMAINS NORTHWEST.
LOW AND MID LEVEL THETA-E RIDGE AXIS WILL LIE JUST SOUTH OF THE
COLORADO STATE LINE AND THERE WILL BE ENOUGH POSITIVE THETA-E
ADVECTION FOR ISOLATED THUNDERSTORMS JUST NORTH OF THE STATE LINE IN
THE AFTERNOON...THEN STORMS ENDING IN THE EVENING WITH LOSS OF
DAYTIME HEATING.

.LONG TERM...(MONDAY THROUGH THURSDAY)
ISSUED AT 300 AM MDT FRI JUL 31 2015

RIDGE AXIS STILL FORECAST TO DRIFT OFF TO THE EAST OF THE CHEYENNE
CWFA MONDAY ALLOWING MONSOONAL MOISTURE TO DRIFT NORTH INTO THE
AREA. SHORTWAVE ENERGY MONDAY NIGHT INTO TUESDAY MORNING MOVES
THROUGH THE AREA. BOTH THE GFS AND ECMWF SHOW THIS HAPPENING.
ECMWF MORE BULLISH ON QPF WHILE GFS KEEP MOST RAINFALL SOUTH IN
COLORADO. FOLLOWED THE ECMWF SOLUTION IN OUR FORECAST AND RAISED
POPS OVER GUIDANCE MONDAY AFTERNOON AND EVENING.

NEED TO BE WATCHING TUESDAY AND WEDNESDAY AS WE COULD BE LOOKING
AT SEVERE THUNDERSTORMS. HAVE A 60KT JET MOVING OVER THE AREA THAT
WILL INTERACT WITH A STALLED OUT FRONTAL BOUNDARY EAST OF THE
LARAMIE RANGE. GFS HAS JET FURTHER NORTH THAN THE ECMWF. WEATHER
DEFINITELY MORE UNSETTLED THROUGH MUCH OF NEXT WEEK.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 513 AM MDT FRI JUL 31 2015

HRRR USED FOR TIMING OF CONVECTION ALONG THE I-80 CORRIDOR THIS
AFTERNOON. HAS CONVECTION DEVELOPING ACROSS THE SOUTH LARAMIE
RANGE AND NORTHERN COLORADO...DRIFTING NORTHEAST INTO THE PLAINS
AFTER 22Z OR SO. CONTINUED VCTS WORDING FOR KCYS...KLAR AND KSNY.

&&

.FIRE WEATHER...
ISSUED AT 152 AM MDT FRI JUL 31 2015

LOW AFTERNOON RELATIVE HUMIDITIES AGAIN IN THE
AFTERNOON WEST OF INTERSTATE 25 THE NEXT FEW DAYS...THOUGH
FORTUNATELY WINDS WILL BE RELATIVELY LIGHT.

&&

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

$$

SHORT TERM...RUBIN
LONG TERM...GCC
AVIATION...GCC
FIRE WEATHER...RUBIN




000
FXUS63 KUNR 311108
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
508 AM MDT FRI JUL 31 2015

.SHORT TERM...TODAY THROUGH SATURDAY NIGHT
ISSUED AT 236 AM MDT FRI JUL 31 2015

BROAD UPPER RIDGING WILL REMAIN ACROSS THE WRN CONUS THROUGH THE
REMAINDER OF THE WEEK. SURFACE HIGH PRESSURE WILL DOMINATE THE NRN
PLAINS TODAY BRINGING GENERALLY DRY WEATHER TO THE AREA.
TEMPERATURES WILL RISE INTO THE UPPER 80S TO MID 90S ACROSS THE
PLAINS...AND 80S OVER THE BLACK HILLS. WITH DEWPOINTS IN THE 40S TO
LOW 50S...THERE WONT BE MUCH MOISTURE/CAPE AVAILABLE FOR CONVECTION.
BUT CANT RULE OUT ISOLATED STORMS OVER THE HILLS INTO THE SRN PTNS
OF THE CWA MAINLY IN THE LATE AFTN/EVNG. OTHERWISE MOSTLY SUNNY
SKIES ARE EXPECTED AREAWIDE WITH RELATIVELY LIGHT WINDS. HIGH
PRESSURE WILL SLIDE EWD TONIGHT WITH RETURN FLOW SETTING UP ACROSS
NE WY/WRN SD. GOOD THETA E ADVECTION SET UP THE LOW/MID LEVELS WITH
STEEP LAPSE RATES. COULD SEE ELEVATED STORMS DEVELOP THROUGH THE
NIGHT...ESPECIALLY AS A SUBTLE UPPER WAVE AND WEAK COLD FRONT CROSS
THE AREA THROUGH EARLY SAT MRNG. BULK OF CONVECTION WILL BE EAST OF
THE CWA BY MID MORNING. WITH DRIER AIR RETURNING TO THE CWA...NOT
MUCH CONVECTION EXPECTED THROUGH THE DAY SATURDAY. HIGHS WILL BE IN
THE MID 80S TO MID 90S.

.LONG TERM...SUNDAY THROUGH THURSDAY
ISSUED AT 236 AM MDT FRI JUL 31 2015

GFS/ECMWF IN DECENT AGREEMENT WITH THE OVERALL PATTERN
FOR MUCH OF NEXT WEEK. HOWEVER...MINOR TIMING DIFFERENCES EXIST WITH
IMPULSES MOVING THROUGH THE NORTHERN PLAINS.

SUNDAY WILL BE WARM AND DRY AS UPPER RIDGE BUILDS ACROSS THE PLAINS.
HIGHS INTO THE 90S WITH RELATIVE HUMIDITY DROPPING TO AROUND 15
PERCENT. MIGHT BE SOME FIRE WEATHER CONCERNS...BUT WINDS LOOK
RELATIVELY LIGHT AT THIS TIME. THUNDERSTORM CHANCES INCREASE FOR THE
FIRST HALF OF THE WEEK. RIDGE BEGINS TO BREAK DOWN MONDAY AS IMPULSE
AND ASSOCIATED PLUME OF MID LEVEL MOISTURE LIFTS FROM THE DESERT
SOUTHWEST INTO THE ROCKIES. MAIN IMPULSE THEN LIFTS INTO THE
NORTHERN PLAINS TUESDAY. FOR THE LAST HALF OF THE WEEK...UPPER HIGH
REMAINS ANCHORED ACROSS THE SOUTHERN/CENTRAL PLAINS...WITH FLAT
RIDGE ACROSS THE NORTHERN PLAINS. SERIES OF SHORTWAVES RIDE OVER THE
RIDGE...WITH LOW LEVEL BAROCLINIC ZONE ACROSS THE AREA. THIS RESULTS
IS A DAILY CHANCE OF THUNDERSTORMS. TEMPERATURES WILL BE NEAR
AVERAGE.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 508 AM MDT FRI JUL 31 2015

VFR CONDITIONS EXPECTED THROUGH TONIGHT.

&&

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

$$

SHORT TERM...13
LONG TERM...7
AVIATION...7



000
FXUS63 KUNR 311108
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
508 AM MDT FRI JUL 31 2015

.SHORT TERM...TODAY THROUGH SATURDAY NIGHT
ISSUED AT 236 AM MDT FRI JUL 31 2015

BROAD UPPER RIDGING WILL REMAIN ACROSS THE WRN CONUS THROUGH THE
REMAINDER OF THE WEEK. SURFACE HIGH PRESSURE WILL DOMINATE THE NRN
PLAINS TODAY BRINGING GENERALLY DRY WEATHER TO THE AREA.
TEMPERATURES WILL RISE INTO THE UPPER 80S TO MID 90S ACROSS THE
PLAINS...AND 80S OVER THE BLACK HILLS. WITH DEWPOINTS IN THE 40S TO
LOW 50S...THERE WONT BE MUCH MOISTURE/CAPE AVAILABLE FOR CONVECTION.
BUT CANT RULE OUT ISOLATED STORMS OVER THE HILLS INTO THE SRN PTNS
OF THE CWA MAINLY IN THE LATE AFTN/EVNG. OTHERWISE MOSTLY SUNNY
SKIES ARE EXPECTED AREAWIDE WITH RELATIVELY LIGHT WINDS. HIGH
PRESSURE WILL SLIDE EWD TONIGHT WITH RETURN FLOW SETTING UP ACROSS
NE WY/WRN SD. GOOD THETA E ADVECTION SET UP THE LOW/MID LEVELS WITH
STEEP LAPSE RATES. COULD SEE ELEVATED STORMS DEVELOP THROUGH THE
NIGHT...ESPECIALLY AS A SUBTLE UPPER WAVE AND WEAK COLD FRONT CROSS
THE AREA THROUGH EARLY SAT MRNG. BULK OF CONVECTION WILL BE EAST OF
THE CWA BY MID MORNING. WITH DRIER AIR RETURNING TO THE CWA...NOT
MUCH CONVECTION EXPECTED THROUGH THE DAY SATURDAY. HIGHS WILL BE IN
THE MID 80S TO MID 90S.

.LONG TERM...SUNDAY THROUGH THURSDAY
ISSUED AT 236 AM MDT FRI JUL 31 2015

GFS/ECMWF IN DECENT AGREEMENT WITH THE OVERALL PATTERN
FOR MUCH OF NEXT WEEK. HOWEVER...MINOR TIMING DIFFERENCES EXIST WITH
IMPULSES MOVING THROUGH THE NORTHERN PLAINS.

SUNDAY WILL BE WARM AND DRY AS UPPER RIDGE BUILDS ACROSS THE PLAINS.
HIGHS INTO THE 90S WITH RELATIVE HUMIDITY DROPPING TO AROUND 15
PERCENT. MIGHT BE SOME FIRE WEATHER CONCERNS...BUT WINDS LOOK
RELATIVELY LIGHT AT THIS TIME. THUNDERSTORM CHANCES INCREASE FOR THE
FIRST HALF OF THE WEEK. RIDGE BEGINS TO BREAK DOWN MONDAY AS IMPULSE
AND ASSOCIATED PLUME OF MID LEVEL MOISTURE LIFTS FROM THE DESERT
SOUTHWEST INTO THE ROCKIES. MAIN IMPULSE THEN LIFTS INTO THE
NORTHERN PLAINS TUESDAY. FOR THE LAST HALF OF THE WEEK...UPPER HIGH
REMAINS ANCHORED ACROSS THE SOUTHERN/CENTRAL PLAINS...WITH FLAT
RIDGE ACROSS THE NORTHERN PLAINS. SERIES OF SHORTWAVES RIDE OVER THE
RIDGE...WITH LOW LEVEL BAROCLINIC ZONE ACROSS THE AREA. THIS RESULTS
IS A DAILY CHANCE OF THUNDERSTORMS. TEMPERATURES WILL BE NEAR
AVERAGE.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 508 AM MDT FRI JUL 31 2015

VFR CONDITIONS EXPECTED THROUGH TONIGHT.

&&

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

$$

SHORT TERM...13
LONG TERM...7
AVIATION...7



000
FXUS63 KUNR 311108
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
508 AM MDT FRI JUL 31 2015

.SHORT TERM...TODAY THROUGH SATURDAY NIGHT
ISSUED AT 236 AM MDT FRI JUL 31 2015

BROAD UPPER RIDGING WILL REMAIN ACROSS THE WRN CONUS THROUGH THE
REMAINDER OF THE WEEK. SURFACE HIGH PRESSURE WILL DOMINATE THE NRN
PLAINS TODAY BRINGING GENERALLY DRY WEATHER TO THE AREA.
TEMPERATURES WILL RISE INTO THE UPPER 80S TO MID 90S ACROSS THE
PLAINS...AND 80S OVER THE BLACK HILLS. WITH DEWPOINTS IN THE 40S TO
LOW 50S...THERE WONT BE MUCH MOISTURE/CAPE AVAILABLE FOR CONVECTION.
BUT CANT RULE OUT ISOLATED STORMS OVER THE HILLS INTO THE SRN PTNS
OF THE CWA MAINLY IN THE LATE AFTN/EVNG. OTHERWISE MOSTLY SUNNY
SKIES ARE EXPECTED AREAWIDE WITH RELATIVELY LIGHT WINDS. HIGH
PRESSURE WILL SLIDE EWD TONIGHT WITH RETURN FLOW SETTING UP ACROSS
NE WY/WRN SD. GOOD THETA E ADVECTION SET UP THE LOW/MID LEVELS WITH
STEEP LAPSE RATES. COULD SEE ELEVATED STORMS DEVELOP THROUGH THE
NIGHT...ESPECIALLY AS A SUBTLE UPPER WAVE AND WEAK COLD FRONT CROSS
THE AREA THROUGH EARLY SAT MRNG. BULK OF CONVECTION WILL BE EAST OF
THE CWA BY MID MORNING. WITH DRIER AIR RETURNING TO THE CWA...NOT
MUCH CONVECTION EXPECTED THROUGH THE DAY SATURDAY. HIGHS WILL BE IN
THE MID 80S TO MID 90S.

.LONG TERM...SUNDAY THROUGH THURSDAY
ISSUED AT 236 AM MDT FRI JUL 31 2015

GFS/ECMWF IN DECENT AGREEMENT WITH THE OVERALL PATTERN
FOR MUCH OF NEXT WEEK. HOWEVER...MINOR TIMING DIFFERENCES EXIST WITH
IMPULSES MOVING THROUGH THE NORTHERN PLAINS.

SUNDAY WILL BE WARM AND DRY AS UPPER RIDGE BUILDS ACROSS THE PLAINS.
HIGHS INTO THE 90S WITH RELATIVE HUMIDITY DROPPING TO AROUND 15
PERCENT. MIGHT BE SOME FIRE WEATHER CONCERNS...BUT WINDS LOOK
RELATIVELY LIGHT AT THIS TIME. THUNDERSTORM CHANCES INCREASE FOR THE
FIRST HALF OF THE WEEK. RIDGE BEGINS TO BREAK DOWN MONDAY AS IMPULSE
AND ASSOCIATED PLUME OF MID LEVEL MOISTURE LIFTS FROM THE DESERT
SOUTHWEST INTO THE ROCKIES. MAIN IMPULSE THEN LIFTS INTO THE
NORTHERN PLAINS TUESDAY. FOR THE LAST HALF OF THE WEEK...UPPER HIGH
REMAINS ANCHORED ACROSS THE SOUTHERN/CENTRAL PLAINS...WITH FLAT
RIDGE ACROSS THE NORTHERN PLAINS. SERIES OF SHORTWAVES RIDE OVER THE
RIDGE...WITH LOW LEVEL BAROCLINIC ZONE ACROSS THE AREA. THIS RESULTS
IS A DAILY CHANCE OF THUNDERSTORMS. TEMPERATURES WILL BE NEAR
AVERAGE.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 508 AM MDT FRI JUL 31 2015

VFR CONDITIONS EXPECTED THROUGH TONIGHT.

&&

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

$$

SHORT TERM...13
LONG TERM...7
AVIATION...7



000
FXUS63 KUNR 311108
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
508 AM MDT FRI JUL 31 2015

.SHORT TERM...TODAY THROUGH SATURDAY NIGHT
ISSUED AT 236 AM MDT FRI JUL 31 2015

BROAD UPPER RIDGING WILL REMAIN ACROSS THE WRN CONUS THROUGH THE
REMAINDER OF THE WEEK. SURFACE HIGH PRESSURE WILL DOMINATE THE NRN
PLAINS TODAY BRINGING GENERALLY DRY WEATHER TO THE AREA.
TEMPERATURES WILL RISE INTO THE UPPER 80S TO MID 90S ACROSS THE
PLAINS...AND 80S OVER THE BLACK HILLS. WITH DEWPOINTS IN THE 40S TO
LOW 50S...THERE WONT BE MUCH MOISTURE/CAPE AVAILABLE FOR CONVECTION.
BUT CANT RULE OUT ISOLATED STORMS OVER THE HILLS INTO THE SRN PTNS
OF THE CWA MAINLY IN THE LATE AFTN/EVNG. OTHERWISE MOSTLY SUNNY
SKIES ARE EXPECTED AREAWIDE WITH RELATIVELY LIGHT WINDS. HIGH
PRESSURE WILL SLIDE EWD TONIGHT WITH RETURN FLOW SETTING UP ACROSS
NE WY/WRN SD. GOOD THETA E ADVECTION SET UP THE LOW/MID LEVELS WITH
STEEP LAPSE RATES. COULD SEE ELEVATED STORMS DEVELOP THROUGH THE
NIGHT...ESPECIALLY AS A SUBTLE UPPER WAVE AND WEAK COLD FRONT CROSS
THE AREA THROUGH EARLY SAT MRNG. BULK OF CONVECTION WILL BE EAST OF
THE CWA BY MID MORNING. WITH DRIER AIR RETURNING TO THE CWA...NOT
MUCH CONVECTION EXPECTED THROUGH THE DAY SATURDAY. HIGHS WILL BE IN
THE MID 80S TO MID 90S.

.LONG TERM...SUNDAY THROUGH THURSDAY
ISSUED AT 236 AM MDT FRI JUL 31 2015

GFS/ECMWF IN DECENT AGREEMENT WITH THE OVERALL PATTERN
FOR MUCH OF NEXT WEEK. HOWEVER...MINOR TIMING DIFFERENCES EXIST WITH
IMPULSES MOVING THROUGH THE NORTHERN PLAINS.

SUNDAY WILL BE WARM AND DRY AS UPPER RIDGE BUILDS ACROSS THE PLAINS.
HIGHS INTO THE 90S WITH RELATIVE HUMIDITY DROPPING TO AROUND 15
PERCENT. MIGHT BE SOME FIRE WEATHER CONCERNS...BUT WINDS LOOK
RELATIVELY LIGHT AT THIS TIME. THUNDERSTORM CHANCES INCREASE FOR THE
FIRST HALF OF THE WEEK. RIDGE BEGINS TO BREAK DOWN MONDAY AS IMPULSE
AND ASSOCIATED PLUME OF MID LEVEL MOISTURE LIFTS FROM THE DESERT
SOUTHWEST INTO THE ROCKIES. MAIN IMPULSE THEN LIFTS INTO THE
NORTHERN PLAINS TUESDAY. FOR THE LAST HALF OF THE WEEK...UPPER HIGH
REMAINS ANCHORED ACROSS THE SOUTHERN/CENTRAL PLAINS...WITH FLAT
RIDGE ACROSS THE NORTHERN PLAINS. SERIES OF SHORTWAVES RIDE OVER THE
RIDGE...WITH LOW LEVEL BAROCLINIC ZONE ACROSS THE AREA. THIS RESULTS
IS A DAILY CHANCE OF THUNDERSTORMS. TEMPERATURES WILL BE NEAR
AVERAGE.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 508 AM MDT FRI JUL 31 2015

VFR CONDITIONS EXPECTED THROUGH TONIGHT.

&&

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

$$

SHORT TERM...13
LONG TERM...7
AVIATION...7



000
FXUS63 KUNR 311108
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
508 AM MDT FRI JUL 31 2015

.SHORT TERM...TODAY THROUGH SATURDAY NIGHT
ISSUED AT 236 AM MDT FRI JUL 31 2015

BROAD UPPER RIDGING WILL REMAIN ACROSS THE WRN CONUS THROUGH THE
REMAINDER OF THE WEEK. SURFACE HIGH PRESSURE WILL DOMINATE THE NRN
PLAINS TODAY BRINGING GENERALLY DRY WEATHER TO THE AREA.
TEMPERATURES WILL RISE INTO THE UPPER 80S TO MID 90S ACROSS THE
PLAINS...AND 80S OVER THE BLACK HILLS. WITH DEWPOINTS IN THE 40S TO
LOW 50S...THERE WONT BE MUCH MOISTURE/CAPE AVAILABLE FOR CONVECTION.
BUT CANT RULE OUT ISOLATED STORMS OVER THE HILLS INTO THE SRN PTNS
OF THE CWA MAINLY IN THE LATE AFTN/EVNG. OTHERWISE MOSTLY SUNNY
SKIES ARE EXPECTED AREAWIDE WITH RELATIVELY LIGHT WINDS. HIGH
PRESSURE WILL SLIDE EWD TONIGHT WITH RETURN FLOW SETTING UP ACROSS
NE WY/WRN SD. GOOD THETA E ADVECTION SET UP THE LOW/MID LEVELS WITH
STEEP LAPSE RATES. COULD SEE ELEVATED STORMS DEVELOP THROUGH THE
NIGHT...ESPECIALLY AS A SUBTLE UPPER WAVE AND WEAK COLD FRONT CROSS
THE AREA THROUGH EARLY SAT MRNG. BULK OF CONVECTION WILL BE EAST OF
THE CWA BY MID MORNING. WITH DRIER AIR RETURNING TO THE CWA...NOT
MUCH CONVECTION EXPECTED THROUGH THE DAY SATURDAY. HIGHS WILL BE IN
THE MID 80S TO MID 90S.

.LONG TERM...SUNDAY THROUGH THURSDAY
ISSUED AT 236 AM MDT FRI JUL 31 2015

GFS/ECMWF IN DECENT AGREEMENT WITH THE OVERALL PATTERN
FOR MUCH OF NEXT WEEK. HOWEVER...MINOR TIMING DIFFERENCES EXIST WITH
IMPULSES MOVING THROUGH THE NORTHERN PLAINS.

SUNDAY WILL BE WARM AND DRY AS UPPER RIDGE BUILDS ACROSS THE PLAINS.
HIGHS INTO THE 90S WITH RELATIVE HUMIDITY DROPPING TO AROUND 15
PERCENT. MIGHT BE SOME FIRE WEATHER CONCERNS...BUT WINDS LOOK
RELATIVELY LIGHT AT THIS TIME. THUNDERSTORM CHANCES INCREASE FOR THE
FIRST HALF OF THE WEEK. RIDGE BEGINS TO BREAK DOWN MONDAY AS IMPULSE
AND ASSOCIATED PLUME OF MID LEVEL MOISTURE LIFTS FROM THE DESERT
SOUTHWEST INTO THE ROCKIES. MAIN IMPULSE THEN LIFTS INTO THE
NORTHERN PLAINS TUESDAY. FOR THE LAST HALF OF THE WEEK...UPPER HIGH
REMAINS ANCHORED ACROSS THE SOUTHERN/CENTRAL PLAINS...WITH FLAT
RIDGE ACROSS THE NORTHERN PLAINS. SERIES OF SHORTWAVES RIDE OVER THE
RIDGE...WITH LOW LEVEL BAROCLINIC ZONE ACROSS THE AREA. THIS RESULTS
IS A DAILY CHANCE OF THUNDERSTORMS. TEMPERATURES WILL BE NEAR
AVERAGE.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 508 AM MDT FRI JUL 31 2015

VFR CONDITIONS EXPECTED THROUGH TONIGHT.

&&

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

$$

SHORT TERM...13
LONG TERM...7
AVIATION...7



000
FXUS63 KUNR 311108
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
508 AM MDT FRI JUL 31 2015

.SHORT TERM...TODAY THROUGH SATURDAY NIGHT
ISSUED AT 236 AM MDT FRI JUL 31 2015

BROAD UPPER RIDGING WILL REMAIN ACROSS THE WRN CONUS THROUGH THE
REMAINDER OF THE WEEK. SURFACE HIGH PRESSURE WILL DOMINATE THE NRN
PLAINS TODAY BRINGING GENERALLY DRY WEATHER TO THE AREA.
TEMPERATURES WILL RISE INTO THE UPPER 80S TO MID 90S ACROSS THE
PLAINS...AND 80S OVER THE BLACK HILLS. WITH DEWPOINTS IN THE 40S TO
LOW 50S...THERE WONT BE MUCH MOISTURE/CAPE AVAILABLE FOR CONVECTION.
BUT CANT RULE OUT ISOLATED STORMS OVER THE HILLS INTO THE SRN PTNS
OF THE CWA MAINLY IN THE LATE AFTN/EVNG. OTHERWISE MOSTLY SUNNY
SKIES ARE EXPECTED AREAWIDE WITH RELATIVELY LIGHT WINDS. HIGH
PRESSURE WILL SLIDE EWD TONIGHT WITH RETURN FLOW SETTING UP ACROSS
NE WY/WRN SD. GOOD THETA E ADVECTION SET UP THE LOW/MID LEVELS WITH
STEEP LAPSE RATES. COULD SEE ELEVATED STORMS DEVELOP THROUGH THE
NIGHT...ESPECIALLY AS A SUBTLE UPPER WAVE AND WEAK COLD FRONT CROSS
THE AREA THROUGH EARLY SAT MRNG. BULK OF CONVECTION WILL BE EAST OF
THE CWA BY MID MORNING. WITH DRIER AIR RETURNING TO THE CWA...NOT
MUCH CONVECTION EXPECTED THROUGH THE DAY SATURDAY. HIGHS WILL BE IN
THE MID 80S TO MID 90S.

.LONG TERM...SUNDAY THROUGH THURSDAY
ISSUED AT 236 AM MDT FRI JUL 31 2015

GFS/ECMWF IN DECENT AGREEMENT WITH THE OVERALL PATTERN
FOR MUCH OF NEXT WEEK. HOWEVER...MINOR TIMING DIFFERENCES EXIST WITH
IMPULSES MOVING THROUGH THE NORTHERN PLAINS.

SUNDAY WILL BE WARM AND DRY AS UPPER RIDGE BUILDS ACROSS THE PLAINS.
HIGHS INTO THE 90S WITH RELATIVE HUMIDITY DROPPING TO AROUND 15
PERCENT. MIGHT BE SOME FIRE WEATHER CONCERNS...BUT WINDS LOOK
RELATIVELY LIGHT AT THIS TIME. THUNDERSTORM CHANCES INCREASE FOR THE
FIRST HALF OF THE WEEK. RIDGE BEGINS TO BREAK DOWN MONDAY AS IMPULSE
AND ASSOCIATED PLUME OF MID LEVEL MOISTURE LIFTS FROM THE DESERT
SOUTHWEST INTO THE ROCKIES. MAIN IMPULSE THEN LIFTS INTO THE
NORTHERN PLAINS TUESDAY. FOR THE LAST HALF OF THE WEEK...UPPER HIGH
REMAINS ANCHORED ACROSS THE SOUTHERN/CENTRAL PLAINS...WITH FLAT
RIDGE ACROSS THE NORTHERN PLAINS. SERIES OF SHORTWAVES RIDE OVER THE
RIDGE...WITH LOW LEVEL BAROCLINIC ZONE ACROSS THE AREA. THIS RESULTS
IS A DAILY CHANCE OF THUNDERSTORMS. TEMPERATURES WILL BE NEAR
AVERAGE.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 508 AM MDT FRI JUL 31 2015

VFR CONDITIONS EXPECTED THROUGH TONIGHT.

&&

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

$$

SHORT TERM...13
LONG TERM...7
AVIATION...7




000
FXUS65 KRIW 310846
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
246 AM MDT FRI JUL 31 2015

.SHORT TERM...TODAY THROUGH SUNDAY NIGHT

WV IMAGERY SHOWING RIDGE WRN CONUS...TROF ERN CONUS. UPR LVL CENTER
OF THIS HIGH LOCATED OVR NM WITH A SMALL BUT STRONGER EMBEDDED WAVE
OVR SFC LOW...VERY TROPICAL LOOKING...OVR THE NRN BAJA REGION.
UPSTREAM OVR WA...WEAK SW ATOP OF RIDGE WHICH WILL ARRIVE OVR NERN
WY THIS EVE. UPR BUBBLE WILL LARGELY PROTECT THE FA AND POINTS
WEST...FOR NOW...FROM MOST PRECIP ACTIVITY...KEEPING LOW CHANCES FOR
POPS OVR THE ERN CWA TO THE HIGH/CNTRL PLAINS. SFC HAS GENERAL HIGH
P ACROSS THE FA...WITH LOW P AND AN ATTENDANT WEAK WARM FRONT FROM
ERN UT INTO WRN CO.

HOT AND DRY FOR THE MOST PART WITH AMPLIFIED PORTION OF THE RIDGE
AXIS CAPPING MOST OF THE FA...KEEPING SHOWERS AND STORMS AT A
MINIMUM...LARGELY RELEGATED ON AN ISOLATED BASIS TO A FEW OF THE
HIGHEST PEAKS...SUCH AS THE ABSAROKAS AND BIGHORNS LATE TODAY/THIS
EVE. ADDITIONALLY TODAY...LOW P OVR UT WILL ALLOW FOR A WEAK WARM
FRONT TO BUILD ACROSS THE WY/CO BORDER AREA...LIFTING ACROSS ERN WY
INTO FRI EVENING WITH SOME MODEST MOISTURE RETURNING TO ERN
WY...WITH SOME LOW CHCS FOR THUNDER BY THIS EVENING AS A SMALL SW
TROF ARRIVES OVERHEAD THRU THE RIDGE THIS EVENING. ATTM...DOES NOT
LOOK LIKE MUCH OF THIS MOISTURE WILL MAKE IT BACK INTO THE ERN
ZONES...BUT CASPER MOUNTAIN...AND TO A LESSER EXTENT THE REST OF
NATRONA OR JOHNSON COUNTY MAY SEE AN ISOLATED LATE DAY T-STORM.
SATURDAY WILL BE WITHOUT PRECIP EVERYWHERE AS DRY AIR ADVECTS FROM
THE WEST OVR THE FA AND ANY SIGNIFICANT MOISTURE IS HELD AT BAY TO
THE SOUTH. SUNDAY...HOTTEST DAY OF THE PERIOD...BUT WEAK MOISTURE
DOES START TO SLOWLY WORK ITS WAY TOWARD AND INTO THE FA THRU THE
DAY...ALLOWING FOR LOW CHANCE PRECIP ACROSS FAVORED MOUNTAIN RANGES
LATER SUNDAY EVENING AND OVERNIGHT PERIOD. THIS WILL BE A PRECURSOR
TO SOMEWHAT BETTER CHCS FOR PRECIP LATER MONDAY...AS THE UPR RIDGE
AXIS ROTATES CLOCKWISE AND CENTERS THRU THE CENTER OF WY...AND SOME
MODEST MONSOONAL TYPE MOISTURE STARTS TO FEED ACROSS THE
INTERMOUNTAIN WEST JUST AHEAD OF  WHAT WAS THE BAJA DISTURBANCE
DESCRIBED ABOVE.

.LONG TERM...MONDAY THROUGH FRIDAY

IT APPEARS THAT THE LONG RANGE MODELS ARE NOW LATCHING ON TO A
WEATHER SYSTEM ROTATING THROUGH THE GREAT BASIN MONDAY. A PORTION
OF THIS WAVE MOVES INTO WY MONDAY AFTERNOON AND THEN PROGRESSES
NORTHWARD THROUGH TUESDAY MORNING. CURRENT FORECAST FOR MONDAY
THROUGH TUESDAY MORNING REFLECTS A HIGHER PRECIP CHANCE IN SOME
AREAS AND DID NOT ALTER THAT FORECAST MUCH. A SOUTHWEST FLOW ALOFT
IS FORECAST TUE PM THROUGH FRIDAY. THIS IS DUE TO AN UPPER LEVEL
STORM SYSTEM THAT ROTATES OFF THE WEST COAST OF CANADA TUESDAY AND
THEN GRADUALLY SINKS SOUTH TO JUST OFF THE NW COAST OF THE U.S.
NEXT FRIDAY. IN THIS SW FLOW ALOFT A FEW WEATHER DISTURBANCES PASS
THROUGH WHICH WOULD BRING A LITTLE HIGHER CHANCE OF STORMS. TIMING
THESE THAT FAR OUT IS NOT EASY OR CONSISTENT. THE 00Z RUNS BRING
ONE DISTURBANCE THROUGH ON WEDNESDAY FOLLOWED BY ANOTHER THURS
NIGHT. I ADJUSTED SOME PRECIP CHANCES ON THOSE DAYS AND NIGHTS BUT
I EXPECT THE TIMING TO CHANGE IN THE COMING DAYS. AS FOR
TEMPS...MONDAY NOW LOOKS COOLER DUE TO MORE CLOUDS AND GREATER
COVERAGE OF SHOWERS OR STORMS. TUE THROUGH FRIDAY WILL BE WARM TO
LOCALLY HOT WITH 80S TO LOW 90S FOR MOST LOWER ELEVATIONS...WITH
UPPER 70S TO LOW 80S IN THE WESTERN VALLEYS. AS STATED
PREVIOUSLY...THE LIGHTNING THAT IS PRODUCED BY THE STORMS NEXT
WEEK WILL LIKELY START SOME FIRES IN PLACES WHERE THE FUELS ARE
RIPE FOR BURNING. THIS THREAT WILL CONTINUE TO BE ANALYZED OVER
THE COMING DAYS.

&&

.AVIATION.../12Z ISSUANCE/

VFR CONDITIONS ARE EXPECTED THROUGH 12Z SATURDAY. THE WIND WILL BE
LIGHT AND VARIABLE AND FOCUS ON TERRAIN INFLUENCES. A FEW FAIR
WEATHER CUMULUS MAY DEVELOP OVER A FEW LOCATIONS. ISOLATED SHOWERS
MAY DEVELOP AFTER 21Z ACROSS EASTERN WYOMING BUT WILL STAY AWAY FROM
TAF SITES.

&&

.FIRE WEATHER...

MINIMUM RH VALUES ARE EXPECTED TO REMAIN IN THE SINGLE DIGITS TO LOW
TEENS THROUGH THE WEEKEND ACROSS THE SOUTH AND LOW ELEVATION AREAS
EAST OF THE DIVIDE...WITH UPPER TEENS AND 20S OVER THE MOUNTAINS.
RELATIVE HUMIDITY WILL HAVE LITTLE TIME RECOVERING
OVERNIGHT...ESPECIALLY AT MID SLOPE WHERE RHS MAY NOT RISE OUT OF
THE MID 20S IN THE CENTRAL WYOMING RANGES. GENERALLY LIGHT WINDS ARE
EXPECTED THROUGH THE WEEKEND...WITH ONLY A FEW LIGHT BREEZES
POSSIBLE IN THE AFTERNOON AND EVENINGS ACROSS THE LOWER ELEVATIONS
OF CENTRAL AND SOUTHERN WYOMING. OTHERWISE...A VERY DRY ATMOSPHERE
WITH HIGH PRESSURE AT THE SURFACE AND ALOFT WILL KEEP MOST CHANCES
FOR ANY PRECIPITATION ISOLATED AND RELEGATED TO MAINLY A FEW
MOUNTAIN OR EASTERN ZONES LATER TODAY. LITTLE IF ANY CHANCE FOR
SHOWERS/STORMS WILL OCCUR ON SATURDAY AT ANY LOCATION. SUNDAY WILL
SEE THE WARMEST TEMPERATURES OF THE WEEKEND...HOWEVER MOISTURE WILL
SLOWLY ALSO BE INCREASING WITH ISOLATED THUNDERSTORM CHANCES
RETURNING LATER IN THE DAY AND OVERNIGHT...WITH WIDELY SCATTERED
CHANCES FOR PRECIPITATION BY MONDAY AFTERNOON.

&&

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

&&

$$

SHORT TERM...BRAUN
LONG TERM...AR
AVIATION...HATTINGS
FIRE WEATHER...BRAUN




000
FXUS65 KRIW 310846
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
246 AM MDT FRI JUL 31 2015

.SHORT TERM...TODAY THROUGH SUNDAY NIGHT

WV IMAGERY SHOWING RIDGE WRN CONUS...TROF ERN CONUS. UPR LVL CENTER
OF THIS HIGH LOCATED OVR NM WITH A SMALL BUT STRONGER EMBEDDED WAVE
OVR SFC LOW...VERY TROPICAL LOOKING...OVR THE NRN BAJA REGION.
UPSTREAM OVR WA...WEAK SW ATOP OF RIDGE WHICH WILL ARRIVE OVR NERN
WY THIS EVE. UPR BUBBLE WILL LARGELY PROTECT THE FA AND POINTS
WEST...FOR NOW...FROM MOST PRECIP ACTIVITY...KEEPING LOW CHANCES FOR
POPS OVR THE ERN CWA TO THE HIGH/CNTRL PLAINS. SFC HAS GENERAL HIGH
P ACROSS THE FA...WITH LOW P AND AN ATTENDANT WEAK WARM FRONT FROM
ERN UT INTO WRN CO.

HOT AND DRY FOR THE MOST PART WITH AMPLIFIED PORTION OF THE RIDGE
AXIS CAPPING MOST OF THE FA...KEEPING SHOWERS AND STORMS AT A
MINIMUM...LARGELY RELEGATED ON AN ISOLATED BASIS TO A FEW OF THE
HIGHEST PEAKS...SUCH AS THE ABSAROKAS AND BIGHORNS LATE TODAY/THIS
EVE. ADDITIONALLY TODAY...LOW P OVR UT WILL ALLOW FOR A WEAK WARM
FRONT TO BUILD ACROSS THE WY/CO BORDER AREA...LIFTING ACROSS ERN WY
INTO FRI EVENING WITH SOME MODEST MOISTURE RETURNING TO ERN
WY...WITH SOME LOW CHCS FOR THUNDER BY THIS EVENING AS A SMALL SW
TROF ARRIVES OVERHEAD THRU THE RIDGE THIS EVENING. ATTM...DOES NOT
LOOK LIKE MUCH OF THIS MOISTURE WILL MAKE IT BACK INTO THE ERN
ZONES...BUT CASPER MOUNTAIN...AND TO A LESSER EXTENT THE REST OF
NATRONA OR JOHNSON COUNTY MAY SEE AN ISOLATED LATE DAY T-STORM.
SATURDAY WILL BE WITHOUT PRECIP EVERYWHERE AS DRY AIR ADVECTS FROM
THE WEST OVR THE FA AND ANY SIGNIFICANT MOISTURE IS HELD AT BAY TO
THE SOUTH. SUNDAY...HOTTEST DAY OF THE PERIOD...BUT WEAK MOISTURE
DOES START TO SLOWLY WORK ITS WAY TOWARD AND INTO THE FA THRU THE
DAY...ALLOWING FOR LOW CHANCE PRECIP ACROSS FAVORED MOUNTAIN RANGES
LATER SUNDAY EVENING AND OVERNIGHT PERIOD. THIS WILL BE A PRECURSOR
TO SOMEWHAT BETTER CHCS FOR PRECIP LATER MONDAY...AS THE UPR RIDGE
AXIS ROTATES CLOCKWISE AND CENTERS THRU THE CENTER OF WY...AND SOME
MODEST MONSOONAL TYPE MOISTURE STARTS TO FEED ACROSS THE
INTERMOUNTAIN WEST JUST AHEAD OF  WHAT WAS THE BAJA DISTURBANCE
DESCRIBED ABOVE.

.LONG TERM...MONDAY THROUGH FRIDAY

IT APPEARS THAT THE LONG RANGE MODELS ARE NOW LATCHING ON TO A
WEATHER SYSTEM ROTATING THROUGH THE GREAT BASIN MONDAY. A PORTION
OF THIS WAVE MOVES INTO WY MONDAY AFTERNOON AND THEN PROGRESSES
NORTHWARD THROUGH TUESDAY MORNING. CURRENT FORECAST FOR MONDAY
THROUGH TUESDAY MORNING REFLECTS A HIGHER PRECIP CHANCE IN SOME
AREAS AND DID NOT ALTER THAT FORECAST MUCH. A SOUTHWEST FLOW ALOFT
IS FORECAST TUE PM THROUGH FRIDAY. THIS IS DUE TO AN UPPER LEVEL
STORM SYSTEM THAT ROTATES OFF THE WEST COAST OF CANADA TUESDAY AND
THEN GRADUALLY SINKS SOUTH TO JUST OFF THE NW COAST OF THE U.S.
NEXT FRIDAY. IN THIS SW FLOW ALOFT A FEW WEATHER DISTURBANCES PASS
THROUGH WHICH WOULD BRING A LITTLE HIGHER CHANCE OF STORMS. TIMING
THESE THAT FAR OUT IS NOT EASY OR CONSISTENT. THE 00Z RUNS BRING
ONE DISTURBANCE THROUGH ON WEDNESDAY FOLLOWED BY ANOTHER THURS
NIGHT. I ADJUSTED SOME PRECIP CHANCES ON THOSE DAYS AND NIGHTS BUT
I EXPECT THE TIMING TO CHANGE IN THE COMING DAYS. AS FOR
TEMPS...MONDAY NOW LOOKS COOLER DUE TO MORE CLOUDS AND GREATER
COVERAGE OF SHOWERS OR STORMS. TUE THROUGH FRIDAY WILL BE WARM TO
LOCALLY HOT WITH 80S TO LOW 90S FOR MOST LOWER ELEVATIONS...WITH
UPPER 70S TO LOW 80S IN THE WESTERN VALLEYS. AS STATED
PREVIOUSLY...THE LIGHTNING THAT IS PRODUCED BY THE STORMS NEXT
WEEK WILL LIKELY START SOME FIRES IN PLACES WHERE THE FUELS ARE
RIPE FOR BURNING. THIS THREAT WILL CONTINUE TO BE ANALYZED OVER
THE COMING DAYS.

&&

.AVIATION.../12Z ISSUANCE/

VFR CONDITIONS ARE EXPECTED THROUGH 12Z SATURDAY. THE WIND WILL BE
LIGHT AND VARIABLE AND FOCUS ON TERRAIN INFLUENCES. A FEW FAIR
WEATHER CUMULUS MAY DEVELOP OVER A FEW LOCATIONS. ISOLATED SHOWERS
MAY DEVELOP AFTER 21Z ACROSS EASTERN WYOMING BUT WILL STAY AWAY FROM
TAF SITES.

&&

.FIRE WEATHER...

MINIMUM RH VALUES ARE EXPECTED TO REMAIN IN THE SINGLE DIGITS TO LOW
TEENS THROUGH THE WEEKEND ACROSS THE SOUTH AND LOW ELEVATION AREAS
EAST OF THE DIVIDE...WITH UPPER TEENS AND 20S OVER THE MOUNTAINS.
RELATIVE HUMIDITY WILL HAVE LITTLE TIME RECOVERING
OVERNIGHT...ESPECIALLY AT MID SLOPE WHERE RHS MAY NOT RISE OUT OF
THE MID 20S IN THE CENTRAL WYOMING RANGES. GENERALLY LIGHT WINDS ARE
EXPECTED THROUGH THE WEEKEND...WITH ONLY A FEW LIGHT BREEZES
POSSIBLE IN THE AFTERNOON AND EVENINGS ACROSS THE LOWER ELEVATIONS
OF CENTRAL AND SOUTHERN WYOMING. OTHERWISE...A VERY DRY ATMOSPHERE
WITH HIGH PRESSURE AT THE SURFACE AND ALOFT WILL KEEP MOST CHANCES
FOR ANY PRECIPITATION ISOLATED AND RELEGATED TO MAINLY A FEW
MOUNTAIN OR EASTERN ZONES LATER TODAY. LITTLE IF ANY CHANCE FOR
SHOWERS/STORMS WILL OCCUR ON SATURDAY AT ANY LOCATION. SUNDAY WILL
SEE THE WARMEST TEMPERATURES OF THE WEEKEND...HOWEVER MOISTURE WILL
SLOWLY ALSO BE INCREASING WITH ISOLATED THUNDERSTORM CHANCES
RETURNING LATER IN THE DAY AND OVERNIGHT...WITH WIDELY SCATTERED
CHANCES FOR PRECIPITATION BY MONDAY AFTERNOON.

&&

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

&&

$$

SHORT TERM...BRAUN
LONG TERM...AR
AVIATION...HATTINGS
FIRE WEATHER...BRAUN



000
FXUS63 KUNR 310839
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
239 AM MDT FRI JUL 31 2015

.SHORT TERM...TODAY THROUGH SATURDAY NIGHT
ISSUED AT 236 AM MDT FRI JUL 31 2015

BROAD UPPER RIDGING WILL REMAIN ACROSS THE WRN CONUS THROUGH THE
REMAINDER OF THE WEEK. SURFACE HIGH PRESSURE WILL DOMINATE THE NRN
PLAINS TODAY BRINGING GENERALLY DRY WEATHER TO THE AREA.
TEMPERATURES WILL RISE INTO THE UPPER 80S TO MID 90S ACROSS THE
PLAINS...AND 80S OVER THE BLACK HILLS. WITH DEWPOINTS IN THE 40S TO
LOW 50S...THERE WONT BE MUCH MOISTURE/CAPE AVAILABLE FOR CONVECTION.
BUT CANT RULE OUT ISOLATED STORMS OVER THE HILLS INTO THE SRN PTNS
OF THE CWA MAINLY IN THE LATE AFTN/EVNG. OTHERWISE MOSTLY SUNNY
SKIES ARE EXPECTED AREAWIDE WITH RELATIVELY LIGHT WINDS. HIGH
PRESSURE WILL SLIDE EWD TONIGHT WITH RETURN FLOW SETTING UP ACROSS
NE WY/WRN SD. GOOD THETA E ADVECTION SET UP THE LOW/MID LEVELS WITH
STEEP LAPSE RATES. COULD SEE ELEVATED STORMS DEVELOP THROUGH THE
NIGHT...ESPECIALLY AS A SUBTLE UPPER WAVE AND WEAK COLD FRONT CROSS
THE AREA THROUGH EARLY SAT MRNG. BULK OF CONVECTION WILL BE EAST OF
THE CWA BY MID MORNING. WITH DRIER AIR RETURNING TO THE CWA...NOT
MUCH CONVECTION EXPECTED THROUGH THE DAY SATURDAY. HIGHS WILL BE IN
THE MID 80S TO MID 90S.

.LONG TERM...SUNDAY THROUGH THURSDAY
ISSUED AT 236 AM MDT FRI JUL 31 2015

GFS/ECMWF IN DECENT AGREEMENT WITH THE OVERALL PATTERN
FOR MUCH OF NEXT WEEK. HOWEVER...MINOR TIMING DIFFERENCES EXIST WITH
IMPULSES MOVING THROUGH THE NORTHERN PLAINS.

SUNDAY WILL BE WARM AND DRY AS UPPER RIDGE BUILDS ACROSS THE PLAINS.
HIGHS INTO THE 90S WITH RELATIVE HUMIDITY DROPPING TO AROUND 15
PERCENT. MIGHT BE SOME FIRE WEATHER CONCERNS...BUT WINDS LOOK
RELATIVELY LIGHT AT THIS TIME. THUNDERSTORM CHANCES INCREASE FOR THE
FIRST HALF OF THE WEEK. RIDGE BEGINS TO BREAK DOWN MONDAY AS IMPULSE
AND ASSOCIATED PLUME OF MID LEVEL MOISTURE LIFTS FROM THE DESERT
SOUTHWEST INTO THE ROCKIES. MAIN IMPULSE THEN LIFTS INTO THE
NORTHERN PLAINS TUESDAY. FOR THE LAST HALF OF THE WEEK...UPPER HIGH
REMAINS ANCHORED ACROSS THE SOUTHERN/CENTRAL PLAINS...WITH FLAT
RIDGE ACROSS THE NORTHERN PLAINS. SERIES OF SHORTWAVES RIDE OVER THE
RIDGE...WITH LOW LEVEL BAROCLINIC ZONE ACROSS THE AREA. THIS RESULTS
IS A DAILY CHANCE OF THUNDERSTORMS. TEMPERATURES WILL BE NEAR
AVERAGE.

&&

.AVIATION...FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT
ISSUED AT 236 AM MDT FRI JUL 31 2015

VFR CONDITIONS EXPECTED THROUGH TONIGHT.

&&

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

$$

SHORT TERM...13
LONG TERM...7
AVIATION...7



000
FXUS63 KUNR 310839
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
239 AM MDT FRI JUL 31 2015

.SHORT TERM...TODAY THROUGH SATURDAY NIGHT
ISSUED AT 236 AM MDT FRI JUL 31 2015

BROAD UPPER RIDGING WILL REMAIN ACROSS THE WRN CONUS THROUGH THE
REMAINDER OF THE WEEK. SURFACE HIGH PRESSURE WILL DOMINATE THE NRN
PLAINS TODAY BRINGING GENERALLY DRY WEATHER TO THE AREA.
TEMPERATURES WILL RISE INTO THE UPPER 80S TO MID 90S ACROSS THE
PLAINS...AND 80S OVER THE BLACK HILLS. WITH DEWPOINTS IN THE 40S TO
LOW 50S...THERE WONT BE MUCH MOISTURE/CAPE AVAILABLE FOR CONVECTION.
BUT CANT RULE OUT ISOLATED STORMS OVER THE HILLS INTO THE SRN PTNS
OF THE CWA MAINLY IN THE LATE AFTN/EVNG. OTHERWISE MOSTLY SUNNY
SKIES ARE EXPECTED AREAWIDE WITH RELATIVELY LIGHT WINDS. HIGH
PRESSURE WILL SLIDE EWD TONIGHT WITH RETURN FLOW SETTING UP ACROSS
NE WY/WRN SD. GOOD THETA E ADVECTION SET UP THE LOW/MID LEVELS WITH
STEEP LAPSE RATES. COULD SEE ELEVATED STORMS DEVELOP THROUGH THE
NIGHT...ESPECIALLY AS A SUBTLE UPPER WAVE AND WEAK COLD FRONT CROSS
THE AREA THROUGH EARLY SAT MRNG. BULK OF CONVECTION WILL BE EAST OF
THE CWA BY MID MORNING. WITH DRIER AIR RETURNING TO THE CWA...NOT
MUCH CONVECTION EXPECTED THROUGH THE DAY SATURDAY. HIGHS WILL BE IN
THE MID 80S TO MID 90S.

.LONG TERM...SUNDAY THROUGH THURSDAY
ISSUED AT 236 AM MDT FRI JUL 31 2015

GFS/ECMWF IN DECENT AGREEMENT WITH THE OVERALL PATTERN
FOR MUCH OF NEXT WEEK. HOWEVER...MINOR TIMING DIFFERENCES EXIST WITH
IMPULSES MOVING THROUGH THE NORTHERN PLAINS.

SUNDAY WILL BE WARM AND DRY AS UPPER RIDGE BUILDS ACROSS THE PLAINS.
HIGHS INTO THE 90S WITH RELATIVE HUMIDITY DROPPING TO AROUND 15
PERCENT. MIGHT BE SOME FIRE WEATHER CONCERNS...BUT WINDS LOOK
RELATIVELY LIGHT AT THIS TIME. THUNDERSTORM CHANCES INCREASE FOR THE
FIRST HALF OF THE WEEK. RIDGE BEGINS TO BREAK DOWN MONDAY AS IMPULSE
AND ASSOCIATED PLUME OF MID LEVEL MOISTURE LIFTS FROM THE DESERT
SOUTHWEST INTO THE ROCKIES. MAIN IMPULSE THEN LIFTS INTO THE
NORTHERN PLAINS TUESDAY. FOR THE LAST HALF OF THE WEEK...UPPER HIGH
REMAINS ANCHORED ACROSS THE SOUTHERN/CENTRAL PLAINS...WITH FLAT
RIDGE ACROSS THE NORTHERN PLAINS. SERIES OF SHORTWAVES RIDE OVER THE
RIDGE...WITH LOW LEVEL BAROCLINIC ZONE ACROSS THE AREA. THIS RESULTS
IS A DAILY CHANCE OF THUNDERSTORMS. TEMPERATURES WILL BE NEAR
AVERAGE.

&&

.AVIATION...FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT
ISSUED AT 236 AM MDT FRI JUL 31 2015

VFR CONDITIONS EXPECTED THROUGH TONIGHT.

&&

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

$$

SHORT TERM...13
LONG TERM...7
AVIATION...7




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