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000
FXUS65 KCYS 230001
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
601 PM MDT FRI AUG 22 2014

.SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT)
ISSUED AT 300 PM MDT FRI AUG 22 2014

PRETTY ACTIVE THE NEXT 24 TO 48 HOURS. TEMPERATURES AND POPS ARE
THE FORECAST CHALLENGES FOR THE SHORT TERM.

CURRENTLY...WATER VAPOR IMAGERY SHOWING A PRETTY PRONOUNCED WAVE
IN THE MONSOONAL FLOW MOVING NORTH THIS AFTERNOON OUT OF NEW
MEXICO INTO WEST CENTRAL COLORADO. MOSAIC RADAR SHOWING WIDESPREAD
SHOWERS OVER CENTRAL COLORADO EARLY THIS AFTERNOON WITH A GENERAL
NORTH NORTHEAST MOVEMENT ON THE CELLS. INFRARED RADAR SHOWING
COOLING CLOUD TOPS WITH THIS WAVE AND WE ARE SEEING AN UPTICK IN
LIGHTNING STRIKES ACROSS WESTERN COLORADO. UPPER LOW OVER IDAHO
FAIRLY DYNAMIC AS WELL WITH NUMEROUS LIGHTNING STRIKES DEVELOPING.
LATEST SPC MESOANALYSIS SHOWING A SLOW EROSION OF CIN OVER EXTREME
SOUTHEAST WYOMING INTO THE KIMBALL AREA...WITH CAPE VALUES
AROUND 1000 J/KG ABOVE. LOOKING AT CLOUD COVER OVERHEAD...IT IS
PRETTY DENSE AND WE HAVE BEEN HARD PRESSED TO GET MUCH WARMING SO
FAR TODAY. 1 PM TEMPERATURES HERE AT THE OFFICE AT 69 DEGREES WITH
LOW TO MID 70S OUT IN THE PANHANDLE.

FOR THIS EVENING...SHORTWAVE BEGINS TO MOVE INTO SOUTHEAST WYOMING
SHORTLY AFTER 00Z WITH GUIDANCE INDICATING FAIRLY WIDESPREAD
CONVECTION DEVELOPING AS THIS HAPPENS. THE 16Z HRRR FORECAST HAS
CONVECTION DEVELOPING HERE AT CHEYENNE AROUND THE 22Z
TIME FRAME...THEN EXPANDING ACROSS SOUTHERN WYOMING INTO THE
PANHANDLE AFTER WARDS. BY 01Z...MOST LOCATIONS EAST OF THE LARAMIE
RANGE SHOULD BE SEEING MEASURABLE RAINFALL WITH SCATTERED SHOWERS
OUT WEST. NAM SOUNDINGS FOR THE PANHANDLE SHOWING PRETTY STRONG
SHEAR OUT IN THE PANHANDLE THIS EVENING. LOOKING AT EASTERLY WINDS
NEAR THE SURFACE OF 15 TO 20KTS WITH SOUTHWEST 40-45KTS AT 6KM.
EVENING SHIFT WILL DEFINITELY NEED TO BE WATCHING FOR SEVERE
THUNDERSTORMS. 0-3KM HELICITY FOR SIDNEY AT 386M2/S2 AT 00Z. GIVEN
THE THICK CLOUD COVER THOUGH...CHANCES ARE DIMMING THAT WE WILL
SEE SEVERE THUNDERSTORMS.

SOMETHING ELSE FOR THIS AFTN/EVE...PRECIPITABLE WATER VALUES
REALLY HIGH FOR THE PANHANDLE. SIDNEY SOUNDING SHOWING 1.42
INCHES...EXTENDING UP TO CHADRON AT 1.40 INCHES. FORECAST QPF
REALLY HIGH FOR THE PANHANDLE AND EXTREME EASTERN WYOMING TONIGHT.
GOOD NEWS IS FORECAST STORM MOTIONS ARE FROM THE SOUTHWEST AT
14-16KTS...SO THESE STORMS SHOULD BE MOVING FAIRLY FAST. WILL NEED
TO WATCH THOUGH FOR TRAINING THUNDERSTORMS AND THERE COULD BE SOME
FLASH FLOODING FOR SOME AREAS THIS EVENING.

GFS AND ECMWF HAVE COME INTO DECENT AGREEMENT WITH THE UPSTREAM
LOW ON THIS 12Z RUN. BOTH SHOWING THE CLOSED LOW MOVING PRETTY
SLOW THROUGH NORTHERN WYOMING THROUGH THE DAY SATURDAY. MOST OF
SATURDAY WILL SEE SHOWERS LASTING MOST OF THE DAY. WENT
SIGNIFICANTLY HIGHER ON POPS OVER GUIDANCE. DO BELIEVE THE MID
SHIFT WILL PROBABLY WANT TO GO HIGHER.

FINALLY SATURDAY EVENING...THE UPPER LOW MOVES OFF INTO SOUTH
DAKOTA WITH RAIN ENDING FROM WEST TO EAST. GOING TO BE PRETTY COOL
WITH 700MB TEMPERATURES DOWN TO +6C SATURDAY NIGHT. SHOULD SEE
WIDESPREAD 40S OUT WEST FOR LOWS...WITH LOW 50S EAST. CLOUD COVER
COULD PROVIDE SLIGHTLY WARMER TEMPERATURES...WE WILL HAVE TO SEE
AS THE EVENT GETS CLOSER. DID GO UNDER GUIDANCE FOR SUNDAY
LOWS...ESPECIALLY OUT WEST WHERE CLOUD COVER WOULD BE LESS.

.LONG TERM...(MONDAY THROUGH FRIDAY)
ISSUED AT 335 PM MDT FRI AUG 22 2014

MEDIUM RANGE MODELS IN GOOD AGREEMENT THROUGH EARLY TUESDAY...BUT
THEN SOLUTIONS BEGIN TO DIVERGE THROUGH WEDNESDAY...WITH POOR
CONSISTENCY BETWEEN THE 12Z AND 00Z MODEL RUNS APPARENT INTO LATE
NEXT WEEK. EARLY IN THE WEEK...MOIST SOUTHWEST FLOW AHEAD OF A
POSITIVELY TILTED UPPER LEVEL TROUGH WILL MOVE ACROSS ACROSS THE
IDAHO AND INTO WESTERN WYOMING. A WEAK BOUNDARY WILL DEVELOP AND
DRIFT WESTWARD ALONG THE LARAMIE RANGE...WHICH WILL RESULT IN
UPSLOPE FLOW AND ENHANCE LIFT ACROSS THE HIGH PLAINS. KEPT POP
BETWEEN 35 TO 60 PERCENT ACROSS THE AREA WITH A GOOD CHANCE OF AT
LEAST SCATTERED SHOWERS AND THUNDERSTORMS. ALL MODELS SHOW THIS
ACTIVITY LINGERING THROUGH MONDAY NIGHT AS WELL AS A WAVE OF LOW
PRESSURE DEVELOPS ALONG THE BOUNDARY...WHICH WILL EVENTUALLY
TRANSITION INTO A COLD FRONT. KEPT POP AROUND 50 PERCENT MONDAY
NIGHT. WILL HAVE TO WATCH FOR STRONG TO SEVERE THUNDERSTORMS
MONDAY EVENING WITH CAPE VALUES AROUND 1500 TO 2000 J/KG...HIGH
PW/S...AND INSTABILITY.

ECMWF STILL TRENDING SLOWER WITH THE UPPER LEVEL TROUGH COMPARED
TO THE GFS. THE GEM HAS TRENDED TOWARDS THE ECMWF WHILE THE GFS
PUSHES THE TROUGH THROUGH THE FORECAST AREA AS EARLY AS TUESDAY
AFTERNOON. THE ECMWF AND GEM SHOW THE TROUGH AXIS MOVING ACROSS
THE AREA LATE TUESDAY NIGHT AND EARLY WEDNESDAY. THE GEM AND ECMWF
SOLUTIONS THEN DIVERGE WITH THE ECMWF SHOWING THE SYSTEM
ATTEMPTING TO CLOSE OFF ON WEDNESDAY. EITHER WAY...EXPECT TUESDAY
AND TUESDAY EVENING TO REMAIN UNSETTLED WITH COOLER THAN NORMAL
TEMPERATURES AND A GOOD CHANCE OF WIDESPREAD RAINFALL. HIGHS MAY
STRUGGLE TO REACH THE MID TO UPPER 60S ON TUESDAY AS 700MB
TEMPERATURES LOWER BELOW 5C AFTER THE FRONT MOVES THROUGH THE
AREA. LOW CONFIDENCE ON THE WEDNESDAY FORECAST DUE TO SIGNIFICANT
MODEL DIFFERENCES. KEPT A SLIGHT CHANCE OF SHOWERS AND TSTORMS FOR
NOW DUE TO TIMING DIFFERENCES...EVEN THOUGH THE ECMWF SOLUTION IS
UNLIKELY TO OCCUR.

MUCH DRIER AIR MOVES INTO THE REGION THURSDAY AND FRIDAY BASED ON
CURRENT MODEL RUNS AS THE RIDGE AXIS REDEVELOPS WEST OF THE ROCKY
MOUNTAINS AND DRIFTS EASTWARD. BASED ON 12Z MODELS...WARMER
TEMPERATURES AND DRY CONDITIONS ARE EXPECTED NEXT WEEK.
HOWEVER...THERE IS A LARGE CONTRAST BETWEEN THESE SOLUTIONS AND
THE PREVIOUS 00Z SOLUTIONS FROM LAST NIGHT WHICH SHOW A PACIFIC
SYSTEM MOVES INTO THE REGION WITH ANOTHER STRONG COLD FRONT
ENTERING WYOMING BY LATE FRIDAY. KEPT TEMPERATURES NEAR NORMAL FOR
NOW WITH POP BELOW 10 PERCENT.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY AFTERNOON)
ISSUED AT 551 PM MDT FRI AUG 22 2014

A FEW ISOLATED THUNDERSTORMS WILL BE FOUND OVER SOUTHEAST WYOMING
AND THE NEBRAKSA PANHANDLE THROUGH EARLY THIS EVENING...BUT WILL
MOSTLY SEE RAIN SHOWERS. CONDITIONS WILL MAINLY REMAIN VFR THROUGH
EARLY THIS EVENING BUT MVFR WILL OCCUR WITH SOME HEAVIER SHOWERS
INTO THE SOUTHERN NEBRASKA PANHANDLE AND NEAR THE COLORADO AND
WYOMING BORDER IN FAR SOUTHEAST WYOMING. INTO THE LATE NIGHT HOURS
IFR CIGS WILL OCCUR OVER MUCH OF SOUTHEAST WYOMING AND NEBRASKA
PANHANDLE...MAINLY ALONG AND EAST OF THE LARAMIE RANGE. FOG IS
POSSIBLE LATE TONIGHT THROUGH MID MORNING SATURDAY WITH POCKETS OF
LIFR. ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS EXPECTED FOR
SATURDAY AFTERNOON AND EVENING.

&&

.FIRE WEATHER...
ISSUED AT 300 PM MDT FRI AUG 22 2014

MINIMAL FIRE WEATHER CONCERNS ACROSS THE AREA THROUGH THE NEXT FEW
DAYS. UPPER LOW PRESSURE OVER IDAHO THIS AFTERNOON WILL BRING
INCREASING MONSOONAL MOISTURE AND FAIRLY WIDESPREAD RAINFALL TO
MUCH OF THE AREA TONIGHT INTO SATURDAY. BEST CHANCES FOR WETTING
RAINS WILL BE ALONG AND EAST OF THE LARAMIE RANGE AS WELL AS THE
SNOWY AND SIERRA MADRE RANGES. THE UPPER LOW WILL GRADUALLY MOVE
INTO WESTERN SOUTH DAKOTA EARLY SUNDAY MORNING WITH RAINS ENDING
FROM WEST TO EAST. COOLER TEMPERATURES BEHIND THE LOW WILL KEEP
AFTERNOON HUMIDITIES FAIRLY HIGH WITH EXCELLENT OVERNIGHT

&&

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

$$

SHORT TERM...CLAYCOMB
LONG TERM...TJT
AVIATION...SML
FIRE WEATHER...CLAYCOMB








000
FXUS65 KCYS 230001
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
601 PM MDT FRI AUG 22 2014

.SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT)
ISSUED AT 300 PM MDT FRI AUG 22 2014

PRETTY ACTIVE THE NEXT 24 TO 48 HOURS. TEMPERATURES AND POPS ARE
THE FORECAST CHALLENGES FOR THE SHORT TERM.

CURRENTLY...WATER VAPOR IMAGERY SHOWING A PRETTY PRONOUNCED WAVE
IN THE MONSOONAL FLOW MOVING NORTH THIS AFTERNOON OUT OF NEW
MEXICO INTO WEST CENTRAL COLORADO. MOSAIC RADAR SHOWING WIDESPREAD
SHOWERS OVER CENTRAL COLORADO EARLY THIS AFTERNOON WITH A GENERAL
NORTH NORTHEAST MOVEMENT ON THE CELLS. INFRARED RADAR SHOWING
COOLING CLOUD TOPS WITH THIS WAVE AND WE ARE SEEING AN UPTICK IN
LIGHTNING STRIKES ACROSS WESTERN COLORADO. UPPER LOW OVER IDAHO
FAIRLY DYNAMIC AS WELL WITH NUMEROUS LIGHTNING STRIKES DEVELOPING.
LATEST SPC MESOANALYSIS SHOWING A SLOW EROSION OF CIN OVER EXTREME
SOUTHEAST WYOMING INTO THE KIMBALL AREA...WITH CAPE VALUES
AROUND 1000 J/KG ABOVE. LOOKING AT CLOUD COVER OVERHEAD...IT IS
PRETTY DENSE AND WE HAVE BEEN HARD PRESSED TO GET MUCH WARMING SO
FAR TODAY. 1 PM TEMPERATURES HERE AT THE OFFICE AT 69 DEGREES WITH
LOW TO MID 70S OUT IN THE PANHANDLE.

FOR THIS EVENING...SHORTWAVE BEGINS TO MOVE INTO SOUTHEAST WYOMING
SHORTLY AFTER 00Z WITH GUIDANCE INDICATING FAIRLY WIDESPREAD
CONVECTION DEVELOPING AS THIS HAPPENS. THE 16Z HRRR FORECAST HAS
CONVECTION DEVELOPING HERE AT CHEYENNE AROUND THE 22Z
TIME FRAME...THEN EXPANDING ACROSS SOUTHERN WYOMING INTO THE
PANHANDLE AFTER WARDS. BY 01Z...MOST LOCATIONS EAST OF THE LARAMIE
RANGE SHOULD BE SEEING MEASURABLE RAINFALL WITH SCATTERED SHOWERS
OUT WEST. NAM SOUNDINGS FOR THE PANHANDLE SHOWING PRETTY STRONG
SHEAR OUT IN THE PANHANDLE THIS EVENING. LOOKING AT EASTERLY WINDS
NEAR THE SURFACE OF 15 TO 20KTS WITH SOUTHWEST 40-45KTS AT 6KM.
EVENING SHIFT WILL DEFINITELY NEED TO BE WATCHING FOR SEVERE
THUNDERSTORMS. 0-3KM HELICITY FOR SIDNEY AT 386M2/S2 AT 00Z. GIVEN
THE THICK CLOUD COVER THOUGH...CHANCES ARE DIMMING THAT WE WILL
SEE SEVERE THUNDERSTORMS.

SOMETHING ELSE FOR THIS AFTN/EVE...PRECIPITABLE WATER VALUES
REALLY HIGH FOR THE PANHANDLE. SIDNEY SOUNDING SHOWING 1.42
INCHES...EXTENDING UP TO CHADRON AT 1.40 INCHES. FORECAST QPF
REALLY HIGH FOR THE PANHANDLE AND EXTREME EASTERN WYOMING TONIGHT.
GOOD NEWS IS FORECAST STORM MOTIONS ARE FROM THE SOUTHWEST AT
14-16KTS...SO THESE STORMS SHOULD BE MOVING FAIRLY FAST. WILL NEED
TO WATCH THOUGH FOR TRAINING THUNDERSTORMS AND THERE COULD BE SOME
FLASH FLOODING FOR SOME AREAS THIS EVENING.

GFS AND ECMWF HAVE COME INTO DECENT AGREEMENT WITH THE UPSTREAM
LOW ON THIS 12Z RUN. BOTH SHOWING THE CLOSED LOW MOVING PRETTY
SLOW THROUGH NORTHERN WYOMING THROUGH THE DAY SATURDAY. MOST OF
SATURDAY WILL SEE SHOWERS LASTING MOST OF THE DAY. WENT
SIGNIFICANTLY HIGHER ON POPS OVER GUIDANCE. DO BELIEVE THE MID
SHIFT WILL PROBABLY WANT TO GO HIGHER.

FINALLY SATURDAY EVENING...THE UPPER LOW MOVES OFF INTO SOUTH
DAKOTA WITH RAIN ENDING FROM WEST TO EAST. GOING TO BE PRETTY COOL
WITH 700MB TEMPERATURES DOWN TO +6C SATURDAY NIGHT. SHOULD SEE
WIDESPREAD 40S OUT WEST FOR LOWS...WITH LOW 50S EAST. CLOUD COVER
COULD PROVIDE SLIGHTLY WARMER TEMPERATURES...WE WILL HAVE TO SEE
AS THE EVENT GETS CLOSER. DID GO UNDER GUIDANCE FOR SUNDAY
LOWS...ESPECIALLY OUT WEST WHERE CLOUD COVER WOULD BE LESS.

.LONG TERM...(MONDAY THROUGH FRIDAY)
ISSUED AT 335 PM MDT FRI AUG 22 2014

MEDIUM RANGE MODELS IN GOOD AGREEMENT THROUGH EARLY TUESDAY...BUT
THEN SOLUTIONS BEGIN TO DIVERGE THROUGH WEDNESDAY...WITH POOR
CONSISTENCY BETWEEN THE 12Z AND 00Z MODEL RUNS APPARENT INTO LATE
NEXT WEEK. EARLY IN THE WEEK...MOIST SOUTHWEST FLOW AHEAD OF A
POSITIVELY TILTED UPPER LEVEL TROUGH WILL MOVE ACROSS ACROSS THE
IDAHO AND INTO WESTERN WYOMING. A WEAK BOUNDARY WILL DEVELOP AND
DRIFT WESTWARD ALONG THE LARAMIE RANGE...WHICH WILL RESULT IN
UPSLOPE FLOW AND ENHANCE LIFT ACROSS THE HIGH PLAINS. KEPT POP
BETWEEN 35 TO 60 PERCENT ACROSS THE AREA WITH A GOOD CHANCE OF AT
LEAST SCATTERED SHOWERS AND THUNDERSTORMS. ALL MODELS SHOW THIS
ACTIVITY LINGERING THROUGH MONDAY NIGHT AS WELL AS A WAVE OF LOW
PRESSURE DEVELOPS ALONG THE BOUNDARY...WHICH WILL EVENTUALLY
TRANSITION INTO A COLD FRONT. KEPT POP AROUND 50 PERCENT MONDAY
NIGHT. WILL HAVE TO WATCH FOR STRONG TO SEVERE THUNDERSTORMS
MONDAY EVENING WITH CAPE VALUES AROUND 1500 TO 2000 J/KG...HIGH
PW/S...AND INSTABILITY.

ECMWF STILL TRENDING SLOWER WITH THE UPPER LEVEL TROUGH COMPARED
TO THE GFS. THE GEM HAS TRENDED TOWARDS THE ECMWF WHILE THE GFS
PUSHES THE TROUGH THROUGH THE FORECAST AREA AS EARLY AS TUESDAY
AFTERNOON. THE ECMWF AND GEM SHOW THE TROUGH AXIS MOVING ACROSS
THE AREA LATE TUESDAY NIGHT AND EARLY WEDNESDAY. THE GEM AND ECMWF
SOLUTIONS THEN DIVERGE WITH THE ECMWF SHOWING THE SYSTEM
ATTEMPTING TO CLOSE OFF ON WEDNESDAY. EITHER WAY...EXPECT TUESDAY
AND TUESDAY EVENING TO REMAIN UNSETTLED WITH COOLER THAN NORMAL
TEMPERATURES AND A GOOD CHANCE OF WIDESPREAD RAINFALL. HIGHS MAY
STRUGGLE TO REACH THE MID TO UPPER 60S ON TUESDAY AS 700MB
TEMPERATURES LOWER BELOW 5C AFTER THE FRONT MOVES THROUGH THE
AREA. LOW CONFIDENCE ON THE WEDNESDAY FORECAST DUE TO SIGNIFICANT
MODEL DIFFERENCES. KEPT A SLIGHT CHANCE OF SHOWERS AND TSTORMS FOR
NOW DUE TO TIMING DIFFERENCES...EVEN THOUGH THE ECMWF SOLUTION IS
UNLIKELY TO OCCUR.

MUCH DRIER AIR MOVES INTO THE REGION THURSDAY AND FRIDAY BASED ON
CURRENT MODEL RUNS AS THE RIDGE AXIS REDEVELOPS WEST OF THE ROCKY
MOUNTAINS AND DRIFTS EASTWARD. BASED ON 12Z MODELS...WARMER
TEMPERATURES AND DRY CONDITIONS ARE EXPECTED NEXT WEEK.
HOWEVER...THERE IS A LARGE CONTRAST BETWEEN THESE SOLUTIONS AND
THE PREVIOUS 00Z SOLUTIONS FROM LAST NIGHT WHICH SHOW A PACIFIC
SYSTEM MOVES INTO THE REGION WITH ANOTHER STRONG COLD FRONT
ENTERING WYOMING BY LATE FRIDAY. KEPT TEMPERATURES NEAR NORMAL FOR
NOW WITH POP BELOW 10 PERCENT.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY AFTERNOON)
ISSUED AT 551 PM MDT FRI AUG 22 2014

A FEW ISOLATED THUNDERSTORMS WILL BE FOUND OVER SOUTHEAST WYOMING
AND THE NEBRAKSA PANHANDLE THROUGH EARLY THIS EVENING...BUT WILL
MOSTLY SEE RAIN SHOWERS. CONDITIONS WILL MAINLY REMAIN VFR THROUGH
EARLY THIS EVENING BUT MVFR WILL OCCUR WITH SOME HEAVIER SHOWERS
INTO THE SOUTHERN NEBRASKA PANHANDLE AND NEAR THE COLORADO AND
WYOMING BORDER IN FAR SOUTHEAST WYOMING. INTO THE LATE NIGHT HOURS
IFR CIGS WILL OCCUR OVER MUCH OF SOUTHEAST WYOMING AND NEBRASKA
PANHANDLE...MAINLY ALONG AND EAST OF THE LARAMIE RANGE. FOG IS
POSSIBLE LATE TONIGHT THROUGH MID MORNING SATURDAY WITH POCKETS OF
LIFR. ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS EXPECTED FOR
SATURDAY AFTERNOON AND EVENING.

&&

.FIRE WEATHER...
ISSUED AT 300 PM MDT FRI AUG 22 2014

MINIMAL FIRE WEATHER CONCERNS ACROSS THE AREA THROUGH THE NEXT FEW
DAYS. UPPER LOW PRESSURE OVER IDAHO THIS AFTERNOON WILL BRING
INCREASING MONSOONAL MOISTURE AND FAIRLY WIDESPREAD RAINFALL TO
MUCH OF THE AREA TONIGHT INTO SATURDAY. BEST CHANCES FOR WETTING
RAINS WILL BE ALONG AND EAST OF THE LARAMIE RANGE AS WELL AS THE
SNOWY AND SIERRA MADRE RANGES. THE UPPER LOW WILL GRADUALLY MOVE
INTO WESTERN SOUTH DAKOTA EARLY SUNDAY MORNING WITH RAINS ENDING
FROM WEST TO EAST. COOLER TEMPERATURES BEHIND THE LOW WILL KEEP
AFTERNOON HUMIDITIES FAIRLY HIGH WITH EXCELLENT OVERNIGHT

&&

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

$$

SHORT TERM...CLAYCOMB
LONG TERM...TJT
AVIATION...SML
FIRE WEATHER...CLAYCOMB







000
FXUS65 KCYS 222129
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
329 PM MDT FRI AUG 22 2014

.SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT)
ISSUED AT 300 PM MDT FRI AUG 22 2014

PRETTY ACTIVE THE NEXT 24 TO 48 HOURS. TEMPERATURES AND POPS ARE
THE FORECAST CHALLENGES FOR THE SHORT TERM.

CURRENTLY...WATER VAPOR IMAGERY SHOWING A PRETTY PRONOUNCED WAVE
IN THE MONSOONAL FLOW MOVING NORTH THIS AFTERNOON OUT OF NEW
MEXICO INTO WEST CENTRAL COLORADO. MOSAIC RADAR SHOWING WIDESPREAD
SHOWERS OVER CENTRAL COLORADO EARLY THIS AFTERNOON WITH A GENERAL
NORTH NORTHEAST MOVEMENT ON THE CELLS. INFRARED RADAR SHOWING
COOLING CLOUD TOPS WITH THIS WAVE AND WE ARE SEEING AN UPTICK IN
LIGHTNING STRIKES ACROSS WESTERN COLORADO. UPPER LOW OVER IDAHO
FAIRLY DYNAMIC AS WELL WITH NUMEROUS LIGHTNING STRIKES DEVELOPING.
LATEST SPC MESOANALYSIS SHOWING A SLOW EROSION OF CIN OVER EXTREME
SOUTHEAST WYOMING INTO THE KIMBALL AREA...WITH CAPE VALUES
AROUND 1000 J/KG ABOVE. LOOKING AT CLOUD COVER OVERHEAD...IT IS
PRETTY DENSE AND WE HAVE BEEN HARD PRESSED TO GET MUCH WARMING SO
FAR TODAY. 1 PM TEMPERATURES HERE AT THE OFFICE AT 69 DEGREES WITH
LOW TO MID 70S OUT IN THE PANHANDLE.

FOR THIS EVENING...SHORTWAVE BEGINS TO MOVE INTO SOUTHEAST WYOMING
SHORTLY AFTER 00Z WITH GUIDANCE INDICATING FAIRLY WIDESPREAD
CONVECTION DEVELOPING AS THIS HAPPENS. THE 16Z HRRR FORECAST HAS
CONVECTION DEVELOPING HERE AT CHEYENNE AROUND THE 22Z
TIME FRAME...THEN EXPANDING ACROSS SOUTHERN WYOMING INTO THE
PANHANDLE AFTER WARDS. BY 01Z...MOST LOCATIONS EAST OF THE LARAMIE
RANGE SHOULD BE SEEING MEASURABLE RAINFALL WITH SCATTERED SHOWERS
OUT WEST. NAM SOUNDINGS FOR THE PANHANDLE SHOWING PRETTY STRONG
SHEAR OUT IN THE PANHANDLE THIS EVENING. LOOKING AT EASTERLY WINDS
NEAR THE SURFACE OF 15 TO 20KTS WITH SOUTHWEST 40-45KTS AT 6KM.
EVENING SHIFT WILL DEFINITELY NEED TO BE WATCHING FOR SEVERE
THUNDERSTORMS. 0-3KM HELICITY FOR SIDNEY AT 386M2/S2 AT 00Z. GIVEN
THE THICK CLOUD COVER THOUGH...CHANCES ARE DIMMING THAT WE WILL
SEE SEVERE THUNDERSTORMS.

SOMETHING ELSE FOR THIS AFTN/EVE...PRECIPITABLE WATER VALUES
REALLY HIGH FOR THE PANHANDLE. SIDNEY SOUNDING SHOWING 1.42
INCHES...EXTENDING UP TO CHADRON AT 1.40 INCHES. FORECAST QPF
REALLY HIGH FOR THE PANHANDLE AND EXTREME EASTERN WYOMING TONIGHT.
GOOD NEWS IS FORECAST STORM MOTIONS ARE FROM THE SOUTHWEST AT
14-16KTS...SO THESE STORMS SHOULD BE MOVING FAIRLY FAST. WILL NEED
TO WATCH THOUGH FOR TRAINING THUNDERSTORMS AND THERE COULD BE SOME
FLASH FLOODING FOR SOME AREAS THIS EVENING.

GFS AND ECMWF HAVE COME INTO DECENT AGREEMENT WITH THE UPSTREAM
LOW ON THIS 12Z RUN. BOTH SHOWING THE CLOSED LOW MOVING PRETTY
SLOW THROUGH NORTHERN WYOMING THROUGH THE DAY SATURDAY. MOST OF
SATURDAY WILL SEE SHOWERS LASTING MOST OF THE DAY. WENT
SIGNIFICANTLY HIGHER ON POPS OVER GUIDANCE. DO BELIEVE THE MID
SHIFT WILL PROBABLY WANT TO GO HIGHER.

FINALLY SATURDAY EVENING...THE UPPER LOW MOVES OFF INTO SOUTH
DAKOTA WITH RAIN ENDING FROM WEST TO EAST. GOING TO BE PRETTY COOL
WITH 700MB TEMPERATURES DOWN TO +6C SATURDAY NIGHT. SHOULD SEE
WIDESPREAD 40S OUT WEST FOR LOWS...WITH LOW 50S EAST. CLOUD COVER
COULD PROVIDE SLIGHTLY WARMER TEMPERATURES...WE WILL HAVE TO SEE
AS THE EVENT GETS CLOSER. DID GO UNDER GUIDANCE FOR SUNDAY
LOWS...ESPECIALLY OUT WEST WHERE CLOUD COVER WOULD BE LESS.

.LONG TERM...(MONDAY THROUGH FRIDAY)
ISSUED AT 335 PM MDT FRI AUG 22 2014

MEDIUM RANGE MODELS IN GOOD AGREEMENT THROUGH EARLY TUESDAY...BUT
THEN SOLUTIONS BEGIN TO DIVERGE THROUGH WEDNESDAY...WITH POOR
CONSISTENCY BETWEEN THE 12Z AND 00Z MODEL RUNS APPARENT INTO LATE
NEXT WEEK. EARLY IN THE WEEK...MOIST SOUTHWEST FLOW AHEAD OF A
POSITIVELY TILTED UPPER LEVEL TROUGH WILL MOVE ACROSS ACROSS THE
IDAHO AND INTO WESTERN WYOMING. A WEAK BOUNDARY WILL DEVELOP AND
DRIFT WESTWARD ALONG THE LARAMIE RANGE...WHICH WILL RESULT IN
UPSLOPE FLOW AND ENHANCE LIFT ACROSS THE HIGH PLAINS. KEPT POP
BETWEEN 35 TO 60 PERCENT ACROSS THE AREA WITH A GOOD CHANCE OF AT
LEAST SCATTERED SHOWERS AND THUNDERSTORMS. ALL MODELS SHOW THIS
ACTIVITY LINGERING THROUGH MONDAY NIGHT AS WELL AS A WAVE OF LOW
PRESSURE DEVELOPS ALONG THE BOUNDARY...WHICH WILL EVENTUALLY
TRANSITION INTO A COLD FRONT. KEPT POP AROUND 50 PERCENT MONDAY
NIGHT. WILL HAVE TO WATCH FOR STRONG TO SEVERE THUNDERSTORMS
MONDAY EVENING WITH CAPE VALUES AROUND 1500 TO 2000 J/KG...HIGH
PW/S...AND INSTABILITY.

ECMWF STILL TRENDING SLOWER WITH THE UPPER LEVEL TROUGH COMPARED
TO THE GFS. THE GEM HAS TRENDED TOWARDS THE ECMWF WHILE THE GFS
PUSHES THE TROUGH THROUGH THE FORECAST AREA AS EARLY AS TUESDAY
AFTERNOON. THE ECMWF AND GEM SHOW THE TROUGH AXIS MOVING ACROSS
THE AREA LATE TUESDAY NIGHT AND EARLY WEDNESDAY. THE GEM AND ECMWF
SOLUTIONS THEN DIVERGE WITH THE ECMWF SHOWING THE SYSTEM
ATTEMPTING TO CLOSE OFF ON WEDNESDAY. EITHER WAY...EXPECT TUESDAY
AND TUESDAY EVENING TO REMAIN UNSETTLED WITH COOLER THAN NORMAL
TEMPERATURES AND A GOOD CHANCE OF WIDESPREAD RAINFALL. HIGHS MAY
STRUGGLE TO REACH THE MID TO UPPER 60S ON TUESDAY AS 700MB
TEMPERATURES LOWER BELOW 5C AFTER THE FRONT MOVES THROUGH THE
AREA. LOW CONFIDENCE ON THE WEDNESDAY FORECAST DUE TO SIGNIFICANT
MODEL DIFFERENCES. KEPT A SLIGHT CHANCE OF SHOWERS AND TSTORMS FOR
NOW DUE TO TIMING DIFFERENCES...EVEN THOUGH THE ECMWF SOLUTION IS
UNLIKELY TO OCCUR.

MUCH DRIER AIR MOVES INTO THE REGION THURSDAY AND FRIDAY BASED ON
CURRENT MODEL RUNS AS THE RIDGE AXIS REDEVELOPS WEST OF THE ROCKY
MOUNTAINS AND DRIFTS EASTWARD. BASED ON 12Z MODELS...WARMER
TEMPERATURES AND DRY CONDITIONS ARE EXPECTED NEXT WEEK.
HOWEVER...THERE IS A LARGE CONTRAST BETWEEN THESE SOLUTIONS AND
THE PREVIOUS 00Z SOLUTIONS FROM LAST NIGHT WHICH SHOW A PACIFIC
SYSTEM MOVES INTO THE REGION WITH ANOTHER STRONG COLD FRONT
ENTERING WYOMING BY LATE FRIDAY. KEPT TEMPERATURES NEAR NORMAL FOR
NOW WITH POP BELOW 10 PERCENT.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY MORNING)
ISSUED AT 1145 AM MDT FRI AUG 22 2014

A BAND OF RAIN SHOWERS AND ISOLATED THUNDER WILL CONTINUE OVER THE
SOUTHERN NEBRASKA PANHANDLE OVER THE NEXT HOUR OR TWO BEFORE
DISSIPATING BY EARLY THIS AFTERNOON. EXPECT A BRIEF BREAK...WITH
MAINLY VFR CONDITIONS THIS AFTERNOON. THE ONLY EXCEPTION WILL BE
KCDR WHICH WILL MAINTAIN A LOW STRATUS DECK. ALL MODELS INDICATE AN
AREA OF HEAVY SHOWERS AND STRONG THUNDERSTORMS DEVELOPING OVER THE
HIGH PLAINS SOMETIME LATE THIS AFTERNOON AS A STRONG UPPER LEVEL
DISTURBANCE LIFT NORTHWARD OUT OF NEW MEXICO...AND WILL CONTINUE TO
MOVE NORTHWARD ACROSS THE AREA TONIGHT. FAIRLY CONFIDENT OF MVFR OR
IFR CONDITIONS IN THESE HEAVY SHOWERS WITH THE POTENTIAL FOR FOG AND
LOW STRATUS RESULTING IN AN EXTENDED PERIOD OF BORDER-LINE IFR
CONDITIONS INTO SATURDAY MORNING ACROSS THE HIGH PLAINS. KRWL AND
KLAR SHOULD REMAIN VFR TONIGHT WITH MOST OF THE ACTIVITY FURTHER TO
THE EAST...BUT CAN NOT RULE OUT SOME SHOWERS AND TSTORMS OVER THOSE
AREAS AS WELL.

&&

.FIRE WEATHER...
ISSUED AT 300 PM MDT FRI AUG 22 2014

MINIMAL FIRE WEATHER CONCERNS ACROSS THE AREA THROUGH THE NEXT FEW
DAYS. UPPER LOW PRESSURE OVER IDAHO THIS AFTERNOON WILL BRING
INCREASING MONSOONAL MOISTURE AND FAIRLY WIDESPREAD RAINFALL TO
MUCH OF THE AREA TONIGHT INTO SATURDAY. BEST CHANCES FOR WETTING
RAINS WILL BE ALONG AND EAST OF THE LARAMIE RANGE AS WELL AS THE
SNOWY AND SIERRA MADRE RANGES. THE UPPER LOW WILL GRADUALLY MOVE
INTO WESTERN SOUTH DAKOTA EARLY SUNDAY MORNING WITH RAINS ENDING
FROM WEST TO EAST. COOLER TEMPERATURES BEHIND THE LOW WILL KEEP
AFTERNOON HUMIDITIES FAIRLY HIGH WITH EXCELLENT OVERNIGHT
RECOVERIES THROUGH THE MIDDLE OF NEXT WEEK.
&&

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

$$

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















000
FXUS65 KCYS 222129
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
329 PM MDT FRI AUG 22 2014

.SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT)
ISSUED AT 300 PM MDT FRI AUG 22 2014

PRETTY ACTIVE THE NEXT 24 TO 48 HOURS. TEMPERATURES AND POPS ARE
THE FORECAST CHALLENGES FOR THE SHORT TERM.

CURRENTLY...WATER VAPOR IMAGERY SHOWING A PRETTY PRONOUNCED WAVE
IN THE MONSOONAL FLOW MOVING NORTH THIS AFTERNOON OUT OF NEW
MEXICO INTO WEST CENTRAL COLORADO. MOSAIC RADAR SHOWING WIDESPREAD
SHOWERS OVER CENTRAL COLORADO EARLY THIS AFTERNOON WITH A GENERAL
NORTH NORTHEAST MOVEMENT ON THE CELLS. INFRARED RADAR SHOWING
COOLING CLOUD TOPS WITH THIS WAVE AND WE ARE SEEING AN UPTICK IN
LIGHTNING STRIKES ACROSS WESTERN COLORADO. UPPER LOW OVER IDAHO
FAIRLY DYNAMIC AS WELL WITH NUMEROUS LIGHTNING STRIKES DEVELOPING.
LATEST SPC MESOANALYSIS SHOWING A SLOW EROSION OF CIN OVER EXTREME
SOUTHEAST WYOMING INTO THE KIMBALL AREA...WITH CAPE VALUES
AROUND 1000 J/KG ABOVE. LOOKING AT CLOUD COVER OVERHEAD...IT IS
PRETTY DENSE AND WE HAVE BEEN HARD PRESSED TO GET MUCH WARMING SO
FAR TODAY. 1 PM TEMPERATURES HERE AT THE OFFICE AT 69 DEGREES WITH
LOW TO MID 70S OUT IN THE PANHANDLE.

FOR THIS EVENING...SHORTWAVE BEGINS TO MOVE INTO SOUTHEAST WYOMING
SHORTLY AFTER 00Z WITH GUIDANCE INDICATING FAIRLY WIDESPREAD
CONVECTION DEVELOPING AS THIS HAPPENS. THE 16Z HRRR FORECAST HAS
CONVECTION DEVELOPING HERE AT CHEYENNE AROUND THE 22Z
TIME FRAME...THEN EXPANDING ACROSS SOUTHERN WYOMING INTO THE
PANHANDLE AFTER WARDS. BY 01Z...MOST LOCATIONS EAST OF THE LARAMIE
RANGE SHOULD BE SEEING MEASURABLE RAINFALL WITH SCATTERED SHOWERS
OUT WEST. NAM SOUNDINGS FOR THE PANHANDLE SHOWING PRETTY STRONG
SHEAR OUT IN THE PANHANDLE THIS EVENING. LOOKING AT EASTERLY WINDS
NEAR THE SURFACE OF 15 TO 20KTS WITH SOUTHWEST 40-45KTS AT 6KM.
EVENING SHIFT WILL DEFINITELY NEED TO BE WATCHING FOR SEVERE
THUNDERSTORMS. 0-3KM HELICITY FOR SIDNEY AT 386M2/S2 AT 00Z. GIVEN
THE THICK CLOUD COVER THOUGH...CHANCES ARE DIMMING THAT WE WILL
SEE SEVERE THUNDERSTORMS.

SOMETHING ELSE FOR THIS AFTN/EVE...PRECIPITABLE WATER VALUES
REALLY HIGH FOR THE PANHANDLE. SIDNEY SOUNDING SHOWING 1.42
INCHES...EXTENDING UP TO CHADRON AT 1.40 INCHES. FORECAST QPF
REALLY HIGH FOR THE PANHANDLE AND EXTREME EASTERN WYOMING TONIGHT.
GOOD NEWS IS FORECAST STORM MOTIONS ARE FROM THE SOUTHWEST AT
14-16KTS...SO THESE STORMS SHOULD BE MOVING FAIRLY FAST. WILL NEED
TO WATCH THOUGH FOR TRAINING THUNDERSTORMS AND THERE COULD BE SOME
FLASH FLOODING FOR SOME AREAS THIS EVENING.

GFS AND ECMWF HAVE COME INTO DECENT AGREEMENT WITH THE UPSTREAM
LOW ON THIS 12Z RUN. BOTH SHOWING THE CLOSED LOW MOVING PRETTY
SLOW THROUGH NORTHERN WYOMING THROUGH THE DAY SATURDAY. MOST OF
SATURDAY WILL SEE SHOWERS LASTING MOST OF THE DAY. WENT
SIGNIFICANTLY HIGHER ON POPS OVER GUIDANCE. DO BELIEVE THE MID
SHIFT WILL PROBABLY WANT TO GO HIGHER.

FINALLY SATURDAY EVENING...THE UPPER LOW MOVES OFF INTO SOUTH
DAKOTA WITH RAIN ENDING FROM WEST TO EAST. GOING TO BE PRETTY COOL
WITH 700MB TEMPERATURES DOWN TO +6C SATURDAY NIGHT. SHOULD SEE
WIDESPREAD 40S OUT WEST FOR LOWS...WITH LOW 50S EAST. CLOUD COVER
COULD PROVIDE SLIGHTLY WARMER TEMPERATURES...WE WILL HAVE TO SEE
AS THE EVENT GETS CLOSER. DID GO UNDER GUIDANCE FOR SUNDAY
LOWS...ESPECIALLY OUT WEST WHERE CLOUD COVER WOULD BE LESS.

.LONG TERM...(MONDAY THROUGH FRIDAY)
ISSUED AT 335 PM MDT FRI AUG 22 2014

MEDIUM RANGE MODELS IN GOOD AGREEMENT THROUGH EARLY TUESDAY...BUT
THEN SOLUTIONS BEGIN TO DIVERGE THROUGH WEDNESDAY...WITH POOR
CONSISTENCY BETWEEN THE 12Z AND 00Z MODEL RUNS APPARENT INTO LATE
NEXT WEEK. EARLY IN THE WEEK...MOIST SOUTHWEST FLOW AHEAD OF A
POSITIVELY TILTED UPPER LEVEL TROUGH WILL MOVE ACROSS ACROSS THE
IDAHO AND INTO WESTERN WYOMING. A WEAK BOUNDARY WILL DEVELOP AND
DRIFT WESTWARD ALONG THE LARAMIE RANGE...WHICH WILL RESULT IN
UPSLOPE FLOW AND ENHANCE LIFT ACROSS THE HIGH PLAINS. KEPT POP
BETWEEN 35 TO 60 PERCENT ACROSS THE AREA WITH A GOOD CHANCE OF AT
LEAST SCATTERED SHOWERS AND THUNDERSTORMS. ALL MODELS SHOW THIS
ACTIVITY LINGERING THROUGH MONDAY NIGHT AS WELL AS A WAVE OF LOW
PRESSURE DEVELOPS ALONG THE BOUNDARY...WHICH WILL EVENTUALLY
TRANSITION INTO A COLD FRONT. KEPT POP AROUND 50 PERCENT MONDAY
NIGHT. WILL HAVE TO WATCH FOR STRONG TO SEVERE THUNDERSTORMS
MONDAY EVENING WITH CAPE VALUES AROUND 1500 TO 2000 J/KG...HIGH
PW/S...AND INSTABILITY.

ECMWF STILL TRENDING SLOWER WITH THE UPPER LEVEL TROUGH COMPARED
TO THE GFS. THE GEM HAS TRENDED TOWARDS THE ECMWF WHILE THE GFS
PUSHES THE TROUGH THROUGH THE FORECAST AREA AS EARLY AS TUESDAY
AFTERNOON. THE ECMWF AND GEM SHOW THE TROUGH AXIS MOVING ACROSS
THE AREA LATE TUESDAY NIGHT AND EARLY WEDNESDAY. THE GEM AND ECMWF
SOLUTIONS THEN DIVERGE WITH THE ECMWF SHOWING THE SYSTEM
ATTEMPTING TO CLOSE OFF ON WEDNESDAY. EITHER WAY...EXPECT TUESDAY
AND TUESDAY EVENING TO REMAIN UNSETTLED WITH COOLER THAN NORMAL
TEMPERATURES AND A GOOD CHANCE OF WIDESPREAD RAINFALL. HIGHS MAY
STRUGGLE TO REACH THE MID TO UPPER 60S ON TUESDAY AS 700MB
TEMPERATURES LOWER BELOW 5C AFTER THE FRONT MOVES THROUGH THE
AREA. LOW CONFIDENCE ON THE WEDNESDAY FORECAST DUE TO SIGNIFICANT
MODEL DIFFERENCES. KEPT A SLIGHT CHANCE OF SHOWERS AND TSTORMS FOR
NOW DUE TO TIMING DIFFERENCES...EVEN THOUGH THE ECMWF SOLUTION IS
UNLIKELY TO OCCUR.

MUCH DRIER AIR MOVES INTO THE REGION THURSDAY AND FRIDAY BASED ON
CURRENT MODEL RUNS AS THE RIDGE AXIS REDEVELOPS WEST OF THE ROCKY
MOUNTAINS AND DRIFTS EASTWARD. BASED ON 12Z MODELS...WARMER
TEMPERATURES AND DRY CONDITIONS ARE EXPECTED NEXT WEEK.
HOWEVER...THERE IS A LARGE CONTRAST BETWEEN THESE SOLUTIONS AND
THE PREVIOUS 00Z SOLUTIONS FROM LAST NIGHT WHICH SHOW A PACIFIC
SYSTEM MOVES INTO THE REGION WITH ANOTHER STRONG COLD FRONT
ENTERING WYOMING BY LATE FRIDAY. KEPT TEMPERATURES NEAR NORMAL FOR
NOW WITH POP BELOW 10 PERCENT.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY MORNING)
ISSUED AT 1145 AM MDT FRI AUG 22 2014

A BAND OF RAIN SHOWERS AND ISOLATED THUNDER WILL CONTINUE OVER THE
SOUTHERN NEBRASKA PANHANDLE OVER THE NEXT HOUR OR TWO BEFORE
DISSIPATING BY EARLY THIS AFTERNOON. EXPECT A BRIEF BREAK...WITH
MAINLY VFR CONDITIONS THIS AFTERNOON. THE ONLY EXCEPTION WILL BE
KCDR WHICH WILL MAINTAIN A LOW STRATUS DECK. ALL MODELS INDICATE AN
AREA OF HEAVY SHOWERS AND STRONG THUNDERSTORMS DEVELOPING OVER THE
HIGH PLAINS SOMETIME LATE THIS AFTERNOON AS A STRONG UPPER LEVEL
DISTURBANCE LIFT NORTHWARD OUT OF NEW MEXICO...AND WILL CONTINUE TO
MOVE NORTHWARD ACROSS THE AREA TONIGHT. FAIRLY CONFIDENT OF MVFR OR
IFR CONDITIONS IN THESE HEAVY SHOWERS WITH THE POTENTIAL FOR FOG AND
LOW STRATUS RESULTING IN AN EXTENDED PERIOD OF BORDER-LINE IFR
CONDITIONS INTO SATURDAY MORNING ACROSS THE HIGH PLAINS. KRWL AND
KLAR SHOULD REMAIN VFR TONIGHT WITH MOST OF THE ACTIVITY FURTHER TO
THE EAST...BUT CAN NOT RULE OUT SOME SHOWERS AND TSTORMS OVER THOSE
AREAS AS WELL.

&&

.FIRE WEATHER...
ISSUED AT 300 PM MDT FRI AUG 22 2014

MINIMAL FIRE WEATHER CONCERNS ACROSS THE AREA THROUGH THE NEXT FEW
DAYS. UPPER LOW PRESSURE OVER IDAHO THIS AFTERNOON WILL BRING
INCREASING MONSOONAL MOISTURE AND FAIRLY WIDESPREAD RAINFALL TO
MUCH OF THE AREA TONIGHT INTO SATURDAY. BEST CHANCES FOR WETTING
RAINS WILL BE ALONG AND EAST OF THE LARAMIE RANGE AS WELL AS THE
SNOWY AND SIERRA MADRE RANGES. THE UPPER LOW WILL GRADUALLY MOVE
INTO WESTERN SOUTH DAKOTA EARLY SUNDAY MORNING WITH RAINS ENDING
FROM WEST TO EAST. COOLER TEMPERATURES BEHIND THE LOW WILL KEEP
AFTERNOON HUMIDITIES FAIRLY HIGH WITH EXCELLENT OVERNIGHT
RECOVERIES THROUGH THE MIDDLE OF NEXT WEEK.
&&

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

$$

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
















000
FXUS65 KCYS 221746
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
1146 AM MDT FRI AUG 22 2014

.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 340 AM MDT FRI AUG 22 2014

TODAY...FLOW ALOFT REMAINS SOUTHWEST...WITH ABUNDANT LOW LEVEL
MOISTURE ADVECTION ON LOW LEVEL SOUTHEAST WINDS. WITH A SHORTWAVE
TROUGH ALOFT ROTATING NORTHEASTWARD FROM COLORADO THIS
AFTERNOON... AND ADEQUATE LOW AND MID LEVEL MOISTURE...WILL SEE
SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS THIS AFTERNOON AND
EVENING...WITH MOST COVERAGE IN PROXIMITY TO THE BEST LOW LEVEL
THETA-E ADVECTION NEAR THE COLORADO STATE LINE FROM LARAMIE TO
SIDNEY.

TONIGHT...SHORTWAVE TROUGH ROTATES NORTHEAST ACROSS OUR WESTERN
NEBRASKA COUNTIES...PRODUCING MORE WIDESPREAD SHOWERS AND
THUNDERSTORMS...POSSIBLY WITH HEAVY RAIN WITH NEAR SATURATED LOW
AND MID LEVELS AND WEAK STEERING FLOW ALOFT.

SATURDAY...UPPER TROUGH MOVES TO NORTHWEST WYOMING WITH A WEAK
SHORTWAVE TROUGH ALOFT MOVING ACROSS FAR EASTERN WYOMING ALONG
WITH ASSOCIATED COLD FRONT. LOOKS LIKE ENOUGH LOW AND MID LEVEL
MOISTURE FOR ISOLATED TO SCATTERED LATE DAY SHOWERS AND
THUNDERSTORMS... THOUGH LESS COVERAGE VERSUS TODAY.

SATURDAY NIGHT...DRIER AND MORE STABLE AIRMASS ADVECTS IN WITH
ISOLATED TO SCATTERED SHOWERS IN THE CYCLONIC FLOW ALOFT EAST OF
INTERSTATE 25.

SUNDAY...LOOKS LIKE A DRY AND WINDY DAY IN THE WAKE OF THE
SHORTWAVE TROUGH PASSAGE...WITH LOW AND MID LEVEL DRYING TAKING
PLACE WITH DECENT DOWNSLOPE WINDS UP TO 700 MB.

.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 340 AM MDT FRI AUG 22 2014

00Z MODEL OUTPUT CONTINUES TO SUGGEST THE UNSETTLED PATTERN EARLY
NEXT WEEK WILL DRY FOR WED-FRI. SO FOR MONDAY...MOIST SOUTHWEST
FLOW AHEAD OF POSITIVELY TILTED UPPER TROF WILL BE IN PLACE. AT
THE SFC...PRESSURE FALLS ALONG THE FRONT RANGE WILL PRODUCE
CONVERGENCE IN THE LLVLS. THE COMBINATION OF THE FAVORABLE
UPSLOPE/CONVERGENT SFC PATTERN COMBINED WITH THE APPROACH WILL SET
THE STAGE FOR DECENT PRECIP CHANCES...ESPECIALLY OVR THE ERN
PLAINS. MODEL PROGD SBCAPES OF 1500-1800 J/KG SUGGEST THAT AT
LEAST THE POTENTIAL EXISTS FOR A FEW STORMS TO BECOME MOST LIKELY
OVR THE WRN NEBRASKA PANHANDLE LATE IN THE DAY. TROF AXIS EDGES
CLOSER MONDAY NIGHT...LIKELY LINGERING CONVECTION. MEDIUM RANGE
MODELS BEGIN TO DIFFER SOME ON TUESDAY...AS THE ECMWF BEGINS TO
TREND SLOWER WITH THE TROUGH AXIS. EVEN SO...IT KEEPS THE TROUGH
AXIS OPEN...MORE IN LINE WITH WHAT THE RECENT GFS/GEM OUTPUT. ALL
MODEL SOLUTIONS SWEEP THE TROF AXIS THRU EITHER ON TUESDAY OR
TUESDAY NIGHT. THE ASSOCIATED COLD FROPA WILL OCCUR SOMETIME ON
TUESDAY...PENDING THE SPEED OF THE SYSTEM. TUESDAY WILL REMAIN
UNSETTLED...THOUGH THERMODYNAMIC PROFILE WILL BE LESS FAVORABLE
FOR ORGANIZED CONVECTION. TUESDAY STILL LOOKS LIKE THE COOLEST DAY
OF THE WEEK IN CAA BEHIND THE FRONT. A MUCH DRIER AIR MASS ALONG
WITH RIDGING BEGINS TO BUILD BACK IN TUESDAY NIGHT THROUGH FRIDAY.
LESS MOISTURE MEANS LESS CLOUD-COVER AND RISING HEIGHTS WILL ALLOW
TEMPS TO RETURN TO SEASONAL NORMS.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH SATURDAY MORNING)
ISSUED AT 1145 AM MDT FRI AUG 22 2014

A BAND OF RAIN SHOWERS AND ISOLATED THUNDER WILL CONTINUE OVER THE
SOUTHERN NEBRASKA PANHANDLE OVER THE NEXT HOUR OR TWO BEFORE
DISSIPATING BY EARLY THIS AFTERNOON. EXPECT A BRIEF BREAK...WITH
MAINLY VFR CONDITIONS THIS AFTERNOON. THE ONLY EXCEPTION WILL BE
KCDR WHICH WILL MAINTAIN A LOW STRATUS DECK. ALL MODELS INDICATE AN
AREA OF HEAVY SHOWERS AND STRONG THUNDERSTORMS DEVELOPING OVER THE
HIGH PLAINS SOMETIME LATE THIS AFTERNOON AS A STRONG UPPER LEVEL
DISTURBANCE LIFT NORTHWARD OUT OF NEW MEXICO...AND WILL CONTINUE TO
MOVE NORTHWARD ACROSS THE AREA TONIGHT. FAIRLY CONFIDENT OF MVFR OR
IFR CONDITIONS IN THESE HEAVY SHOWERS WITH THE POTENTIAL FOR FOG AND
LOW STRATUS RESULTING IN AN EXTENDED PERIOD OF BORDER-LINE IFR
CONDITIONS INTO SATURDAY MORNING ACROSS THE HIGH PLAINS. KRWL AND
KLAR SHOULD REMAIN VFR TONIGHT WITH MOST OF THE ACTIVITY FURTHER TO
THE EAST...BUT CAN NOT RULE OUT SOME SHOWERS AND TSTORMS OVER THOSE
AREAS AS WELL.

&&

.FIRE WEATHER...
ISSUED AT 340 AM MDT FRI AUG 22 2014

MINIMAL CONCERNS AS THE WINDS AND HUMIDITIES REMAIN BELOW
CRITICAL THRESHOLDS.

&&

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

&&

$$

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









000
FXUS65 KCYS 221746
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
1146 AM MDT FRI AUG 22 2014

.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 340 AM MDT FRI AUG 22 2014

TODAY...FLOW ALOFT REMAINS SOUTHWEST...WITH ABUNDANT LOW LEVEL
MOISTURE ADVECTION ON LOW LEVEL SOUTHEAST WINDS. WITH A SHORTWAVE
TROUGH ALOFT ROTATING NORTHEASTWARD FROM COLORADO THIS
AFTERNOON... AND ADEQUATE LOW AND MID LEVEL MOISTURE...WILL SEE
SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS THIS AFTERNOON AND
EVENING...WITH MOST COVERAGE IN PROXIMITY TO THE BEST LOW LEVEL
THETA-E ADVECTION NEAR THE COLORADO STATE LINE FROM LARAMIE TO
SIDNEY.

TONIGHT...SHORTWAVE TROUGH ROTATES NORTHEAST ACROSS OUR WESTERN
NEBRASKA COUNTIES...PRODUCING MORE WIDESPREAD SHOWERS AND
THUNDERSTORMS...POSSIBLY WITH HEAVY RAIN WITH NEAR SATURATED LOW
AND MID LEVELS AND WEAK STEERING FLOW ALOFT.

SATURDAY...UPPER TROUGH MOVES TO NORTHWEST WYOMING WITH A WEAK
SHORTWAVE TROUGH ALOFT MOVING ACROSS FAR EASTERN WYOMING ALONG
WITH ASSOCIATED COLD FRONT. LOOKS LIKE ENOUGH LOW AND MID LEVEL
MOISTURE FOR ISOLATED TO SCATTERED LATE DAY SHOWERS AND
THUNDERSTORMS... THOUGH LESS COVERAGE VERSUS TODAY.

SATURDAY NIGHT...DRIER AND MORE STABLE AIRMASS ADVECTS IN WITH
ISOLATED TO SCATTERED SHOWERS IN THE CYCLONIC FLOW ALOFT EAST OF
INTERSTATE 25.

SUNDAY...LOOKS LIKE A DRY AND WINDY DAY IN THE WAKE OF THE
SHORTWAVE TROUGH PASSAGE...WITH LOW AND MID LEVEL DRYING TAKING
PLACE WITH DECENT DOWNSLOPE WINDS UP TO 700 MB.

.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 340 AM MDT FRI AUG 22 2014

00Z MODEL OUTPUT CONTINUES TO SUGGEST THE UNSETTLED PATTERN EARLY
NEXT WEEK WILL DRY FOR WED-FRI. SO FOR MONDAY...MOIST SOUTHWEST
FLOW AHEAD OF POSITIVELY TILTED UPPER TROF WILL BE IN PLACE. AT
THE SFC...PRESSURE FALLS ALONG THE FRONT RANGE WILL PRODUCE
CONVERGENCE IN THE LLVLS. THE COMBINATION OF THE FAVORABLE
UPSLOPE/CONVERGENT SFC PATTERN COMBINED WITH THE APPROACH WILL SET
THE STAGE FOR DECENT PRECIP CHANCES...ESPECIALLY OVR THE ERN
PLAINS. MODEL PROGD SBCAPES OF 1500-1800 J/KG SUGGEST THAT AT
LEAST THE POTENTIAL EXISTS FOR A FEW STORMS TO BECOME MOST LIKELY
OVR THE WRN NEBRASKA PANHANDLE LATE IN THE DAY. TROF AXIS EDGES
CLOSER MONDAY NIGHT...LIKELY LINGERING CONVECTION. MEDIUM RANGE
MODELS BEGIN TO DIFFER SOME ON TUESDAY...AS THE ECMWF BEGINS TO
TREND SLOWER WITH THE TROUGH AXIS. EVEN SO...IT KEEPS THE TROUGH
AXIS OPEN...MORE IN LINE WITH WHAT THE RECENT GFS/GEM OUTPUT. ALL
MODEL SOLUTIONS SWEEP THE TROF AXIS THRU EITHER ON TUESDAY OR
TUESDAY NIGHT. THE ASSOCIATED COLD FROPA WILL OCCUR SOMETIME ON
TUESDAY...PENDING THE SPEED OF THE SYSTEM. TUESDAY WILL REMAIN
UNSETTLED...THOUGH THERMODYNAMIC PROFILE WILL BE LESS FAVORABLE
FOR ORGANIZED CONVECTION. TUESDAY STILL LOOKS LIKE THE COOLEST DAY
OF THE WEEK IN CAA BEHIND THE FRONT. A MUCH DRIER AIR MASS ALONG
WITH RIDGING BEGINS TO BUILD BACK IN TUESDAY NIGHT THROUGH FRIDAY.
LESS MOISTURE MEANS LESS CLOUD-COVER AND RISING HEIGHTS WILL ALLOW
TEMPS TO RETURN TO SEASONAL NORMS.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH SATURDAY MORNING)
ISSUED AT 1145 AM MDT FRI AUG 22 2014

A BAND OF RAIN SHOWERS AND ISOLATED THUNDER WILL CONTINUE OVER THE
SOUTHERN NEBRASKA PANHANDLE OVER THE NEXT HOUR OR TWO BEFORE
DISSIPATING BY EARLY THIS AFTERNOON. EXPECT A BRIEF BREAK...WITH
MAINLY VFR CONDITIONS THIS AFTERNOON. THE ONLY EXCEPTION WILL BE
KCDR WHICH WILL MAINTAIN A LOW STRATUS DECK. ALL MODELS INDICATE AN
AREA OF HEAVY SHOWERS AND STRONG THUNDERSTORMS DEVELOPING OVER THE
HIGH PLAINS SOMETIME LATE THIS AFTERNOON AS A STRONG UPPER LEVEL
DISTURBANCE LIFT NORTHWARD OUT OF NEW MEXICO...AND WILL CONTINUE TO
MOVE NORTHWARD ACROSS THE AREA TONIGHT. FAIRLY CONFIDENT OF MVFR OR
IFR CONDITIONS IN THESE HEAVY SHOWERS WITH THE POTENTIAL FOR FOG AND
LOW STRATUS RESULTING IN AN EXTENDED PERIOD OF BORDER-LINE IFR
CONDITIONS INTO SATURDAY MORNING ACROSS THE HIGH PLAINS. KRWL AND
KLAR SHOULD REMAIN VFR TONIGHT WITH MOST OF THE ACTIVITY FURTHER TO
THE EAST...BUT CAN NOT RULE OUT SOME SHOWERS AND TSTORMS OVER THOSE
AREAS AS WELL.

&&

.FIRE WEATHER...
ISSUED AT 340 AM MDT FRI AUG 22 2014

MINIMAL CONCERNS AS THE WINDS AND HUMIDITIES REMAIN BELOW
CRITICAL THRESHOLDS.

&&

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

&&

$$

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










000
FXUS65 KCYS 220941
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
341 AM MDT FRI AUG 22 2014

.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 340 AM MDT FRI AUG 22 2014

TODAY...FLOW ALOFT REMAINS SOUTHWEST...WITH ABUNDANT LOW LEVEL
MOISTURE ADVECTION ON LOW LEVEL SOUTHEAST WINDS. WITH A SHORTWAVE
TROUGH ALOFT ROTATING NORTHEASTWARD FROM COLORADO THIS
AFTERNOON... AND ADEQUATE LOW AND MID LEVEL MOISTURE...WILL SEE
SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS THIS AFTERNOON AND
EVENING...WITH MOST COVERAGE IN PROXIMITY TO THE BEST LOW LEVEL
THETA-E ADVECTION NEAR THE COLORADO STATE LINE FROM LARAMIE TO
SIDNEY.

TONIGHT...SHORTWAVE TROUGH ROTATES NORTHEAST ACROSS OUR WESTERN
NEBRASKA COUNTIES...PRODUCING MORE WIDESPREAD SHOWERS AND
THUNDERSTORMS...POSSIBLY WITH HEAVY RAIN WITH NEAR SATURATED LOW
AND MID LEVELS AND WEAK STEERING FLOW ALOFT.

SATURDAY...UPPER TROUGH MOVES TO NORTHWEST WYOMING WITH A WEAK
SHORTWAVE TROUGH ALOFT MOVING ACROSS FAR EASTERN WYOMING ALONG
WITH ASSOCIATED COLD FRONT. LOOKS LIKE ENOUGH LOW AND MID LEVEL
MOISTURE FOR ISOLATED TO SCATTERED LATE DAY SHOWERS AND
THUNDERSTORMS... THOUGH LESS COVERAGE VERSUS TODAY.

SATURDAY NIGHT...DRIER AND MORE STABLE AIRMASS ADVECTS IN WITH
ISOLATED TO SCATTERED SHOWERS IN THE CYCLONIC FLOW ALOFT EAST OF
INTERSTATE 25.

SUNDAY...LOOKS LIKE A DRY AND WINDY DAY IN THE WAKE OF THE
SHORTWAVE TROUGH PASSAGE...WITH LOW AND MID LEVEL DRYING TAKING
PLACE WITH DECENT DOWNSLOPE WINDS UP TO 700 MB.

.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 340 AM MDT FRI AUG 22 2014

00Z MODEL OUTPUT CONTINUES TO SUGGEST THE UNSETTLED PATTERN EARLY
NEXT WEEK WILL DRY FOR WED-FRI. SO FOR MONDAY...MOIST SOUTHWEST
FLOW AHEAD OF POSITIVELY TILTED UPPER TROF WILL BE IN PLACE. AT
THE SFC...PRESSURE FALLS ALONG THE FRONT RANGE WILL PRODUCE
CONVERGENCE IN THE LLVLS. THE COMBINATION OF THE FAVORABLE
UPSLOPE/CONVERGENT SFC PATTERN COMBINED WITH THE APPROACH WILL SET
THE STAGE FOR DECENT PRECIP CHANCES...ESPECIALLY OVR THE ERN
PLAINS. MODEL PROGD SBCAPES OF 1500-1800 J/KG SUGGEST THAT AT
LEAST THE POTENTIAL EXISTS FOR A FEW STORMS TO BECOME MOST LIKELY
OVR THE WRN NEBRASKA PANHANDLE LATE IN THE DAY. TROF AXIS EDGES
CLOSER MONDAY NIGHT...LIKELY LINGERING CONVECTION. MEDIUM RANGE
MODELS BEGIN TO DIFFER SOME ON TUESDAY...AS THE ECMWF BEGINS TO
TREND SLOWER WITH THE TROUGH AXIS. EVEN SO...IT KEEPS THE TROUGH
AXIS OPEN...MORE IN LINE WITH WHAT THE RECENT GFS/GEM OUTPUT. ALL
MODEL SOLUTIONS SWEEP THE TROF AXIS THRU EITHER ON TUESDAY OR
TUESDAY NIGHT. THE ASSOCIATED COLD FROPA WILL OCCUR SOMETIME ON
TUESDAY...PENDING THE SPEED OF THE SYSTEM. TUESDAY WILL REMAIN
UNSETTLED...THOUGH THERMODYNAMIC PROFILE WILL BE LESS FAVORABLE
FOR ORGANIZED CONVECTION. TUESDAY STILL LOOKS LIKE THE COOLEST DAY
OF THE WEEK IN CAA BEHIND THE FRONT. A MUCH DRIER AIR MASS ALONG
WITH RIDGING BEGINS TO BUILD BACK IN TUESDAY NIGHT THROUGH FRIDAY.
LESS MOISTURE MEANS LESS CLOUD-COVER AND RISING HEIGHTS WILL ALLOW
TEMPS TO RETURN TO SEASONAL NORMS.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 340 AM MDT FRI AUG 22 2014

RADARS SHOW SOME LIGHT SHOWER ACTIVITY STREAMING NORTHEAST OUT OF
NORTHEAST COLORADO THIS MORNING. THE TRAJECTORY WOULD STEER IT
TOWARDS KSNY...THOUGH OBSERVATIONS SHOW LITTLE IF ANY RAIN WAS
FALLING. OVERALL...EXPECT A VFR DAY AHEAD...THOUGH ISOLATED SHOWER
AND THUNDERSTORMS WILL BE A POSSIBLE FOR MOST SITES. NOT CONFIDENT
ENOUGH IN TIMING OR PLACEMENT TO ADD ANYTHING MORE THAN VCTS. THIS
ACTIVITY WILL LIKLEY LINGER THRU THE EVENING AND INTO THE
OVERNIGHT AT WRN NEBRASKA AIRFIELDS. MAY EVEN SEE A PERIOD OF
MVFR/IFR CIGS OR VISIBILITIES THERE THIS EVENING. ENOUGH
UNCERTAINTY REMAINS TO NOT INCLUDE IN THE TAFS YET. THERE SHOULD
BE A BRIEF BREAK BEHIND THIS ACTIVITY TOWARDS THE END OF THE TAF
PERIOD...HOWEVER MORE CONVECTION WILL BE ON ITS HEELS FOR
SATURDAY.

&&

.FIRE WEATHER...
ISSUED AT 340 AM MDT FRI AUG 22 2014

MINIMAL CONCERNS AS THE WINDS AND HUMIDITIES REMAIN BELOW
CRITICAL THRESHOLDS.

&&

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

&&

$$

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






000
FXUS65 KCYS 220644
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
1244 AM MDT FRI AUG 22 2014

.UPDATE...
ISSUED AT 911 PM MDT THU AUG 21 2014

SHOWERS AND THUNDERSTORMS ARE STARTING TO WIND DOWN ACROSS THE
AREA THIS EVENING. A FEW WILL LINGER THROUGH THE EVENING HOURS
WITH MOST ACTIVITY ENDING BY MIDNIGHT. ISOLATED ACTIVITY COULD
OCCUR LATE TONIGHT WITH A BIT OF ELEVATED INSTABILITY AND WARM
ADVECTION. FORECAST LOOKS IN GOOD SHAPE SO NO MAJOR UPDATE AT THIS
TIME.

&&

.SHORT TERM...(THIS EVENING THROUGH SATURDAY NIGHT)
ISSUED AT 300 PM MDT THU AUG 21 2014

CURRENT KCYS RADAR LOOP SHOWS A FEW SHOWERS ACROSS THE AREA AND NO
THUNDERSTORMS AT THIS TIME...WHICH WAS EXPECTED DUE TO INCREASED
SUBSIDENCE ALOFT. IN ADDITION...HIGH CLOUDS ARE MOVING NORTHWARD
NEAR THE COLORADO BORDER WHICH WILL SUPPRESS CONVECTION EVEN MORE.
KEPT POP NEAR OR BELOW 20 PERCENT FOR ISOLATED SHOWERS AND SOME
ISOLATED THUNDER AT TIMES. LOWERED POP TO AROUND 10 PERCENT IN THE
LOWER VALLEYS INTO THIS EVENING. EXPECT MOST OF THE THUNDERSTORM
ACTIVITY TO BE FURTHER NORTH AS A COOL FRONT DRIFTS SOUTHWARD AND
STALLS ACROSS CENTRAL WYOMING.

MODELS CONTINUE TO SHOW A CHANGE IN THE OVERALL PATTERN ACROSS THE
ROCKY MOUNTAIN REGION FOR FRIDAY AND THIS WEEKEND. ALL MODELS
INDICATE A PRETTY STRONG COLD FRONT FOR THIS TIME OF THE YEAR
PUSHING SOUTHWARD INTO SOUTHEAST WYOMING. THIS FRONT WILL STALL
SOMETIME ON FRIDAY AS A WAVE OF LOW PRESSURE DEVELOPS ALONG THE
FRONT...AND WILL BE THE MAIN FOCUS FOR SCATTERED TO NUMEROUS SHOWERS
AND TSTORMS AS AN UPPER LEVEL TROUGH FROM WESTERN CANADA MOVE
SOUTH AND EVENTUALLY EASTWARD INTO IDAHO. THE MAIN FORECAST
CONCERN FOR FRIDAY AND FRIDAY NIGHT IS THE POTENTIAL FOR A STEADY
HEAVY RAINFALL AS AN UPPER LEVEL TROUGH NEAR THE SOUTHERN CALIF
COASTLINE EJECTS NORTHEASTWARD ACROSS THE AREA. THE ECMWF AND NAM
ARE THE MOST AGGRESSIVE WITH THE FEATURE SHOWING WIDESPREAD
SHOWERS AND NUMEROUS TSTORMS DEVELOPING ACROSS COLORADO AND
QUICKLY MOVING NORTHWARD INTO THE FORECAST AREA. THE GFS IS THE
LEAST AGGRESSIVE AND SHOWS THE TROUGH MUCH WEAKER AS IT LIFT
NORTHEAST...AND IS BARELY NOTICEABLE BY LATE FRIDAY ACROSS THE
PLAINS. INCREASED POP UP TO 65 PERCENT ACROSS THE HIGH
PLAINS...MOSTLY OVER FAR EASTERN WYOMING AND WESTERN NEBRASKA.
RAIN SHOWERS AND EVEN ISOLATED TSTORMS MAY CONTINUE WELL INTO THE
OVERNIGHT HOURS INTO EARLY SATURDAY MORNING.

FOR SATURDAY...MODELS SHOW A BRIEF BREAK IN THE ACTION BY MID TO
LATE MORNING AS REMNANT SHOWER ACTIVITY MOVES INTO THE DAKOTAS.
SHOWER AND TSTORMS WILL QUICKLY REDEVELOP FURTHER WEST ACROSS
WYOMING/UTAH AND NORTHWEST COLORADO AS THE MAIN COLD FRONT AND
PRETTY STRONG UPPER LEVEL TROUGH MOVES EASTWARD FROM IDAHO INTO
WYOMING. EXPECT ANOTHER ROUND OF SHOWERS AND TSTORMS AHEAD AND
ALONG THIS FRONT...WHICH SOME DECENT RAINFALL AMOUNTS POSSIBLE.
INCREASED POP BETWEEN 40 TO 60 PERCENT ACROSS MOST AREAS SATURDAY
AFTERNOON AND EVENING. CLEARING SKIES ARE EXPECTED AFTER MIDNIGHT
ACROSS SOUTHEAST WYOMING WITH MUCH COOLER TEMPERATURES. A FEW
SHELTERED VALLEYS MAY LOWER INTO THE 30S SATURDAY NIGHT WITH
NEAR FREEZING TEMPERATURES IN THE MOUNTAINS.

.LONG TERM...(SUNDAY THROUGH THURSDAY)
ISSUED AT 330 PM MDT THU AUG 21 2014

MODELS VERY SIMILAR ON MOVEMENT OF UPPER LOW INTO WESTERN MONTANA
EARLY SUNDAY. SUNDAY COULD BE A PRETTY BREEZY DAY AS THE LOW
PLACEMENT IN A FAVORABLE POSITION FOR STRONG WINDS. IN FACT...THE
ECMWF 700MB WINDS ACROSS SOUTHEAST WYOMING ARE APPROACHING
40KTS...GFS A LITTLE LIGHTER WITH 30-35KTS. SHOULD NOT BE MUCH IN
THE WAY OF SHOWER ACTIVITY WITH DOWNSLOPING WINDS OFF THE LARAMIE
RANGE.

NEXT SHORTWAVE TO IMPACT THE AREA COMES IN FROM THE NORTHWEST
AROUND THAT LOW MONDAY AFTERNOON. BOTH THE GFS AND ECMWF SHOWING
MOUNTAIN SHOWERS INITIALLY. THE ECMWF IS FORECASTING A MORE
WIDESPREAD SHOWERY EVENT...THOUGH GFS DOES SHOW AN INCREASE IN
COVERAGE MONDAY NIGHT. PRETTY MUCH KEPT WHAT WE HAD GOING FOR POPS
MONDAY WITH BEST CHANCES IN THE MOUNTAINS.

DISCREPANCIES BEGIN TO INCREASE AFTER THIS SHORTWAVE AS THE ECMWF
SLOWER IN MOVING OUT THIS TROUGH. BY TUESDAY AFTERNOON...THE ECMWF
SHOWS THE UPPER TROUGH AXIS OVER EXTREME EASTERN WYOMING AND THE
GFS HAS IT ALREADY MOVING INTO CENTRAL NEBRASKA. WITH THE SLOWER
ECMWF...WE REALLY BEGIN TO SEE THE DISCREPANCIES ARISE IN 700MB
TEMPERATURES. GFS FORECASTING +4 TO +8C OVER THE CWFA WITH THE
ECMWF SHOWING +10 TO +12C. DID BEGIN TO GO LOWER ON TEMPERATURES
MORE IN LINE WITH THE GFS. UNDERCUT EXTENDED PROCEDURE GUIDANCE BY
3-4 DEGREES TO COME MORE IN LINE WITH THE GFS/MEX GUIDANCE.
LOOKS FAIRY DRY WEDNESDAY AFTERNOON AND INTO THURSDAY WITH THE
TROUGH MOVING OFF TO THE EAST.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1243 AM MDT FRI AUG 22 2014

ISOLATED SHOWERS CONTINUE ALONG AND NORTH OF INTERSTATE 80 LATE THIS
EVENING. THIS ACTIVITY SHOULD DIMINISH OVER THE NEXT FEW HOURS WITH
VFR CONDITIONS EXPECTED FOR ALL TERMINALS OVERNIGHT. BKN-TO-OVC SKY
COVER WITH CIGS AROUND 10K FEET AGL WILL BE THE RULE FOR MOST AREAS
THROUGH THE TAF PERIOD. LOOK FOR SCATTERED SHOWERS AND THUNDERSTORMS
AFTER 18Z FRI...PERHAPS LINGERING WELL INTO THE NIGHT OVER THE NE
PANHANDLE. GUSTY/VARIABLE WINDS AND MVFR CIGS OR VSBYS CAN BE
EXPECTED WITH HEAVIER CONVECTION. MVFR/IFR CONDITIONS COULD DEVELOP
OVER THE PANHANDLE AFTER 03Z SAT. DID NOT MENTION IN THIS TAF
ISSUANCE AS CONFIDENCE IN THIS SCENARIO IS LOW ATTM.

&&

.FIRE WEATHER...
ISSUED AT 205 PM MDT THU AUG 21 2014

MINIMAL FIRE WEATHER CONCERNS THROUGH EARLY NEXT WEEK.
SUBTROPICAL MOISTURE WILL REMAIN OVER THE AREA THROUGH THE WEEKEND
WITH SHOWERS AND THUNDERSTORMS POSSIBLE EACH DAY ACROSS SOUTHEAST
WYOMING AND WESTERN NEBRASKA. THERE IS A GOOD CHANCE OF WETTING
RAINS ON FRIDAY THROUGH THIS WEEKEND AS SHOWERS AND THUNDERSTORM
COVERAGE WILL BE HIGHER. TEMPERATURES WILL TREND COOLER INTO THIS
WEEKEND AS A STRONG COLD FRONT FOR THIS TIME OF THE YEAR MOVES
INTO THE REGION LATE ON SATURDAY. THIS UNSETTLED WEATHER IS
EXPECTED TO CONTINUE INTO EARLY NEXT WEEK.

&&

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

$$

UPDATE...SML
SHORT TERM...TJT
LONG TERM...CLAYCOMB
AVIATION...HAMMER
FIRE WEATHER...TJT







000
FXUS65 KCYS 220311
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
911 PM MDT THU AUG 21 2014

.UPDATE...
ISSUED AT 911 PM MDT THU AUG 21 2014

SHOWERS AND THUNDERSTORMS ARE STARTING TO WIND DOWN ACROSS THE
AREA THIS EVENING. A FEW WILL LINGER THROUGH THE EVENING HOURS
WITH MOST ACTIVITY ENDING BY MIDNIGHT. ISOLATED ACTIVITY COULD
OCCUR LATE TONIGHT WITH A BIT OF ELEVATED INSTABILITY AND WARM
ADVECTION. FORECAST LOOKS IN GOOD SHAPE SO NO MAJOR UPDATE AT THIS
TIME.

&&

.SHORT TERM...(THIS EVENING THROUGH SATURDAY NIGHT)
ISSUED AT 300 PM MDT THU AUG 21 2014

CURRENT KCYS RADAR LOOP SHOWS A FEW SHOWERS ACROSS THE AREA AND NO
THUNDERSTORMS AT THIS TIME...WHICH WAS EXPECTED DUE TO INCREASED
SUBSIDENCE ALOFT. IN ADDITION...HIGH CLOUDS ARE MOVING NORTHWARD
NEAR THE COLORADO BORDER WHICH WILL SUPPRESS CONVECTION EVEN MORE.
KEPT POP NEAR OR BELOW 20 PERCENT FOR ISOLATED SHOWERS AND SOME
ISOLATED THUNDER AT TIMES. LOWERED POP TO AROUND 10 PERCENT IN THE
LOWER VALLEYS INTO THIS EVENING. EXPECT MOST OF THE THUNDERSTORM
ACTIVITY TO BE FURTHER NORTH AS A COOL FRONT DRIFTS SOUTHWARD AND
STALLS ACROSS CENTRAL WYOMING.

MODELS CONTINUE TO SHOW A CHANGE IN THE OVERALL PATTERN ACROSS THE
ROCKY MOUNTAIN REGION FOR FRIDAY AND THIS WEEKEND. ALL MODELS
INDICATE A PRETTY STRONG COLD FRONT FOR THIS TIME OF THE YEAR
PUSHING SOUTHWARD INTO SOUTHEAST WYOMING. THIS FRONT WILL STALL
SOMETIME ON FRIDAY AS A WAVE OF LOW PRESSURE DEVELOPS ALONG THE
FRONT...AND WILL BE THE MAIN FOCUS FOR SCATTERED TO NUMEROUS SHOWERS
AND TSTORMS AS AN UPPER LEVEL TROUGH FROM WESTERN CANADA MOVE
SOUTH AND EVENTUALLY EASTWARD INTO IDAHO. THE MAIN FORECAST
CONCERN FOR FRIDAY AND FRIDAY NIGHT IS THE POTENTIAL FOR A STEADY
HEAVY RAINFALL AS AN UPPER LEVEL TROUGH NEAR THE SOUTHERN CALIF
COASTLINE EJECTS NORTHEASTWARD ACROSS THE AREA. THE ECMWF AND NAM
ARE THE MOST AGGRESSIVE WITH THE FEATURE SHOWING WIDESPREAD
SHOWERS AND NUMEROUS TSTORMS DEVELOPING ACROSS COLORADO AND
QUICKLY MOVING NORTHWARD INTO THE FORECAST AREA. THE GFS IS THE
LEAST AGGRESSIVE AND SHOWS THE TROUGH MUCH WEAKER AS IT LIFT
NORTHEAST...AND IS BARELY NOTICEABLE BY LATE FRIDAY ACROSS THE
PLAINS. INCREASED POP UP TO 65 PERCENT ACROSS THE HIGH
PLAINS...MOSTLY OVER FAR EASTERN WYOMING AND WESTERN NEBRASKA.
RAIN SHOWERS AND EVEN ISOLATED TSTORMS MAY CONTINUE WELL INTO THE
OVERNIGHT HOURS INTO EARLY SATURDAY MORNING.

FOR SATURDAY...MODELS SHOW A BRIEF BREAK IN THE ACTION BY MID TO
LATE MORNING AS REMNANT SHOWER ACTIVITY MOVES INTO THE DAKOTAS.
SHOWER AND TSTORMS WILL QUICKLY REDEVELOP FURTHER WEST ACROSS
WYOMING/UTAH AND NORTHWEST COLORADO AS THE MAIN COLD FRONT AND
PRETTY STRONG UPPER LEVEL TROUGH MOVES EASTWARD FROM IDAHO INTO
WYOMING. EXPECT ANOTHER ROUND OF SHOWERS AND TSTORMS AHEAD AND
ALONG THIS FRONT...WHICH SOME DECENT RAINFALL AMOUNTS POSSIBLE.
INCREASED POP BETWEEN 40 TO 60 PERCENT ACROSS MOST AREAS SATURDAY
AFTERNOON AND EVENING. CLEARING SKIES ARE EXPECTED AFTER MIDNIGHT
ACROSS SOUTHEAST WYOMING WITH MUCH COOLER TEMPERATURES. A FEW
SHELTERED VALLEYS MAY LOWER INTO THE 30S SATURDAY NIGHT WITH
NEAR FREEZING TEMPERATURES IN THE MOUNTAINS.

.LONG TERM...(SUNDAY THROUGH THURSDAY)
ISSUED AT 330 PM MDT THU AUG 21 2014

MODELS VERY SIMILAR ON MOVEMENT OF UPPER LOW INTO WESTERN MONTANA
EARLY SUNDAY. SUNDAY COULD BE A PRETTY BREEZY DAY AS THE LOW
PLACEMENT IN A FAVORABLE POSITION FOR STRONG WINDS. IN FACT...THE
ECMWF 700MB WINDS ACROSS SOUTHEAST WYOMING ARE APPROACHING
40KTS...GFS A LITTLE LIGHTER WITH 30-35KTS. SHOULD NOT BE MUCH IN
THE WAY OF SHOWER ACTIVITY WITH DOWNSLOPING WINDS OFF THE LARAMIE
RANGE.

NEXT SHORTWAVE TO IMPACT THE AREA COMES IN FROM THE NORTHWEST
AROUND THAT LOW MONDAY AFTERNOON. BOTH THE GFS AND ECMWF SHOWING
MOUNTAIN SHOWERS INITIALLY. THE ECMWF IS FORECASTING A MORE
WIDESPREAD SHOWERY EVENT...THOUGH GFS DOES SHOW AN INCREASE IN
COVERAGE MONDAY NIGHT. PRETTY MUCH KEPT WHAT WE HAD GOING FOR POPS
MONDAY WITH BEST CHANCES IN THE MOUNTAINS.

DISCREPANCIES BEGIN TO INCREASE AFTER THIS SHORTWAVE AS THE ECMWF
SLOWER IN MOVING OUT THIS TROUGH. BY TUESDAY AFTERNOON...THE ECMWF
SHOWS THE UPPER TROUGH AXIS OVER EXTREME EASTERN WYOMING AND THE
GFS HAS IT ALREADY MOVING INTO CENTRAL NEBRASKA. WITH THE SLOWER
ECMWF...WE REALLY BEGIN TO SEE THE DISCREPANCIES ARISE IN 700MB
TEMPERATURES. GFS FORECASTING +4 TO +8C OVER THE CWFA WITH THE
ECMWF SHOWING +10 TO +12C. DID BEGIN TO GO LOWER ON TEMPERATURES
MORE IN LINE WITH THE GFS. UNDERCUT EXTENDED PROCEDURE GUIDANCE BY
3-4 DEGREES TO COME MORE IN LINE WITH THE GFS/MEX GUIDANCE.
LOOKS FAIRY DRY WEDNESDAY AFTERNOON AND INTO THURSDAY WITH THE
TROUGH MOVING OFF TO THE EAST.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY AFTERNOON)
ISSUED AT 535 PM MDT THU AUG 21 2014

VFR CONDITIONS SHOULD BE THE RULE FOR ALL TERMINALS THROUGH MOST
OF THE TAF PERIOD. ISOLATED TO SCATTERED SHOWERS AND TSTMS WILL
PERSIST THROUGH MID EVE ACROSS SOUTHEAST WY AND THE WESTERN NE
PANHANDLE. MAINTAINED VCTS AT KRWL...KCYS AND KBFF AS THESE ARE
THE MOST LIKELY AREAS TO SEE CONVECTION THROUGH 03Z FRI. BRIEF
MVFR VSBYS AND GUSTY WINDS MAY ACCOMPANY SOME STORMS. OTHERWISE
SKIES WILL REMAIN BKN-TO-OVC ABOVE 10K FEET AGL. FRI AFTN WILL
FEATURE LOWERING CLOUD BASES AND ANOTHER ROUND OF SHOWERS AND
TSTMS. SOME STORMS COULD BE STRONG.


&&

.FIRE WEATHER...
ISSUED AT 205 PM MDT THU AUG 21 2014

MINIMAL FIRE WEATHER CONCERNS THROUGH EARLY NEXT WEEK.
SUBTROPICAL MOISTURE WILL REMAIN OVER THE AREA THROUGH THE WEEKEND
WITH SHOWERS AND THUNDERSTORMS POSSIBLE EACH DAY ACROSS SOUTHEAST
WYOMING AND WESTERN NEBRASKA. THERE IS A GOOD CHANCE OF WETTING
RAINS ON FRIDAY THROUGH THIS WEEKEND AS SHOWERS AND THUNDERSTORM
COVERAGE WILL BE HIGHER. TEMPERATURES WILL TREND COOLER INTO THIS
WEEKEND AS A STRONG COLD FRONT FOR THIS TIME OF THE YEAR MOVES
INTO THE REGION LATE ON SATURDAY. THIS UNSETTLED WEATHER IS
EXPECTED TO CONTINUE INTO EARLY NEXT WEEK.

&&

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

&&

$$

UPDATE...SML
SHORT TERM...TJT
LONG TERM...CLAYCOMB
AVIATION...HAMMER
FIRE WEATHER...TJT








000
FXUS65 KCYS 220311
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
911 PM MDT THU AUG 21 2014

.UPDATE...
ISSUED AT 911 PM MDT THU AUG 21 2014

SHOWERS AND THUNDERSTORMS ARE STARTING TO WIND DOWN ACROSS THE
AREA THIS EVENING. A FEW WILL LINGER THROUGH THE EVENING HOURS
WITH MOST ACTIVITY ENDING BY MIDNIGHT. ISOLATED ACTIVITY COULD
OCCUR LATE TONIGHT WITH A BIT OF ELEVATED INSTABILITY AND WARM
ADVECTION. FORECAST LOOKS IN GOOD SHAPE SO NO MAJOR UPDATE AT THIS
TIME.

&&

.SHORT TERM...(THIS EVENING THROUGH SATURDAY NIGHT)
ISSUED AT 300 PM MDT THU AUG 21 2014

CURRENT KCYS RADAR LOOP SHOWS A FEW SHOWERS ACROSS THE AREA AND NO
THUNDERSTORMS AT THIS TIME...WHICH WAS EXPECTED DUE TO INCREASED
SUBSIDENCE ALOFT. IN ADDITION...HIGH CLOUDS ARE MOVING NORTHWARD
NEAR THE COLORADO BORDER WHICH WILL SUPPRESS CONVECTION EVEN MORE.
KEPT POP NEAR OR BELOW 20 PERCENT FOR ISOLATED SHOWERS AND SOME
ISOLATED THUNDER AT TIMES. LOWERED POP TO AROUND 10 PERCENT IN THE
LOWER VALLEYS INTO THIS EVENING. EXPECT MOST OF THE THUNDERSTORM
ACTIVITY TO BE FURTHER NORTH AS A COOL FRONT DRIFTS SOUTHWARD AND
STALLS ACROSS CENTRAL WYOMING.

MODELS CONTINUE TO SHOW A CHANGE IN THE OVERALL PATTERN ACROSS THE
ROCKY MOUNTAIN REGION FOR FRIDAY AND THIS WEEKEND. ALL MODELS
INDICATE A PRETTY STRONG COLD FRONT FOR THIS TIME OF THE YEAR
PUSHING SOUTHWARD INTO SOUTHEAST WYOMING. THIS FRONT WILL STALL
SOMETIME ON FRIDAY AS A WAVE OF LOW PRESSURE DEVELOPS ALONG THE
FRONT...AND WILL BE THE MAIN FOCUS FOR SCATTERED TO NUMEROUS SHOWERS
AND TSTORMS AS AN UPPER LEVEL TROUGH FROM WESTERN CANADA MOVE
SOUTH AND EVENTUALLY EASTWARD INTO IDAHO. THE MAIN FORECAST
CONCERN FOR FRIDAY AND FRIDAY NIGHT IS THE POTENTIAL FOR A STEADY
HEAVY RAINFALL AS AN UPPER LEVEL TROUGH NEAR THE SOUTHERN CALIF
COASTLINE EJECTS NORTHEASTWARD ACROSS THE AREA. THE ECMWF AND NAM
ARE THE MOST AGGRESSIVE WITH THE FEATURE SHOWING WIDESPREAD
SHOWERS AND NUMEROUS TSTORMS DEVELOPING ACROSS COLORADO AND
QUICKLY MOVING NORTHWARD INTO THE FORECAST AREA. THE GFS IS THE
LEAST AGGRESSIVE AND SHOWS THE TROUGH MUCH WEAKER AS IT LIFT
NORTHEAST...AND IS BARELY NOTICEABLE BY LATE FRIDAY ACROSS THE
PLAINS. INCREASED POP UP TO 65 PERCENT ACROSS THE HIGH
PLAINS...MOSTLY OVER FAR EASTERN WYOMING AND WESTERN NEBRASKA.
RAIN SHOWERS AND EVEN ISOLATED TSTORMS MAY CONTINUE WELL INTO THE
OVERNIGHT HOURS INTO EARLY SATURDAY MORNING.

FOR SATURDAY...MODELS SHOW A BRIEF BREAK IN THE ACTION BY MID TO
LATE MORNING AS REMNANT SHOWER ACTIVITY MOVES INTO THE DAKOTAS.
SHOWER AND TSTORMS WILL QUICKLY REDEVELOP FURTHER WEST ACROSS
WYOMING/UTAH AND NORTHWEST COLORADO AS THE MAIN COLD FRONT AND
PRETTY STRONG UPPER LEVEL TROUGH MOVES EASTWARD FROM IDAHO INTO
WYOMING. EXPECT ANOTHER ROUND OF SHOWERS AND TSTORMS AHEAD AND
ALONG THIS FRONT...WHICH SOME DECENT RAINFALL AMOUNTS POSSIBLE.
INCREASED POP BETWEEN 40 TO 60 PERCENT ACROSS MOST AREAS SATURDAY
AFTERNOON AND EVENING. CLEARING SKIES ARE EXPECTED AFTER MIDNIGHT
ACROSS SOUTHEAST WYOMING WITH MUCH COOLER TEMPERATURES. A FEW
SHELTERED VALLEYS MAY LOWER INTO THE 30S SATURDAY NIGHT WITH
NEAR FREEZING TEMPERATURES IN THE MOUNTAINS.

.LONG TERM...(SUNDAY THROUGH THURSDAY)
ISSUED AT 330 PM MDT THU AUG 21 2014

MODELS VERY SIMILAR ON MOVEMENT OF UPPER LOW INTO WESTERN MONTANA
EARLY SUNDAY. SUNDAY COULD BE A PRETTY BREEZY DAY AS THE LOW
PLACEMENT IN A FAVORABLE POSITION FOR STRONG WINDS. IN FACT...THE
ECMWF 700MB WINDS ACROSS SOUTHEAST WYOMING ARE APPROACHING
40KTS...GFS A LITTLE LIGHTER WITH 30-35KTS. SHOULD NOT BE MUCH IN
THE WAY OF SHOWER ACTIVITY WITH DOWNSLOPING WINDS OFF THE LARAMIE
RANGE.

NEXT SHORTWAVE TO IMPACT THE AREA COMES IN FROM THE NORTHWEST
AROUND THAT LOW MONDAY AFTERNOON. BOTH THE GFS AND ECMWF SHOWING
MOUNTAIN SHOWERS INITIALLY. THE ECMWF IS FORECASTING A MORE
WIDESPREAD SHOWERY EVENT...THOUGH GFS DOES SHOW AN INCREASE IN
COVERAGE MONDAY NIGHT. PRETTY MUCH KEPT WHAT WE HAD GOING FOR POPS
MONDAY WITH BEST CHANCES IN THE MOUNTAINS.

DISCREPANCIES BEGIN TO INCREASE AFTER THIS SHORTWAVE AS THE ECMWF
SLOWER IN MOVING OUT THIS TROUGH. BY TUESDAY AFTERNOON...THE ECMWF
SHOWS THE UPPER TROUGH AXIS OVER EXTREME EASTERN WYOMING AND THE
GFS HAS IT ALREADY MOVING INTO CENTRAL NEBRASKA. WITH THE SLOWER
ECMWF...WE REALLY BEGIN TO SEE THE DISCREPANCIES ARISE IN 700MB
TEMPERATURES. GFS FORECASTING +4 TO +8C OVER THE CWFA WITH THE
ECMWF SHOWING +10 TO +12C. DID BEGIN TO GO LOWER ON TEMPERATURES
MORE IN LINE WITH THE GFS. UNDERCUT EXTENDED PROCEDURE GUIDANCE BY
3-4 DEGREES TO COME MORE IN LINE WITH THE GFS/MEX GUIDANCE.
LOOKS FAIRY DRY WEDNESDAY AFTERNOON AND INTO THURSDAY WITH THE
TROUGH MOVING OFF TO THE EAST.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY AFTERNOON)
ISSUED AT 535 PM MDT THU AUG 21 2014

VFR CONDITIONS SHOULD BE THE RULE FOR ALL TERMINALS THROUGH MOST
OF THE TAF PERIOD. ISOLATED TO SCATTERED SHOWERS AND TSTMS WILL
PERSIST THROUGH MID EVE ACROSS SOUTHEAST WY AND THE WESTERN NE
PANHANDLE. MAINTAINED VCTS AT KRWL...KCYS AND KBFF AS THESE ARE
THE MOST LIKELY AREAS TO SEE CONVECTION THROUGH 03Z FRI. BRIEF
MVFR VSBYS AND GUSTY WINDS MAY ACCOMPANY SOME STORMS. OTHERWISE
SKIES WILL REMAIN BKN-TO-OVC ABOVE 10K FEET AGL. FRI AFTN WILL
FEATURE LOWERING CLOUD BASES AND ANOTHER ROUND OF SHOWERS AND
TSTMS. SOME STORMS COULD BE STRONG.


&&

.FIRE WEATHER...
ISSUED AT 205 PM MDT THU AUG 21 2014

MINIMAL FIRE WEATHER CONCERNS THROUGH EARLY NEXT WEEK.
SUBTROPICAL MOISTURE WILL REMAIN OVER THE AREA THROUGH THE WEEKEND
WITH SHOWERS AND THUNDERSTORMS POSSIBLE EACH DAY ACROSS SOUTHEAST
WYOMING AND WESTERN NEBRASKA. THERE IS A GOOD CHANCE OF WETTING
RAINS ON FRIDAY THROUGH THIS WEEKEND AS SHOWERS AND THUNDERSTORM
COVERAGE WILL BE HIGHER. TEMPERATURES WILL TREND COOLER INTO THIS
WEEKEND AS A STRONG COLD FRONT FOR THIS TIME OF THE YEAR MOVES
INTO THE REGION LATE ON SATURDAY. THIS UNSETTLED WEATHER IS
EXPECTED TO CONTINUE INTO EARLY NEXT WEEK.

&&

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

&&

$$

UPDATE...SML
SHORT TERM...TJT
LONG TERM...CLAYCOMB
AVIATION...HAMMER
FIRE WEATHER...TJT









000
FXUS65 KCYS 212341
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
541 PM MDT THU AUG 21 2014

.SHORT TERM...(THIS EVENING THROUGH SATURDAY NIGHT)
ISSUED AT 300 PM MDT THU AUG 21 2014

CURRENT KCYS RADAR LOOP SHOWS A FEW SHOWERS ACROSS THE AREA AND NO
THUNDERSTORMS AT THIS TIME...WHICH WAS EXPECTED DUE TO INCREASED
SUBSIDENCE ALOFT. IN ADDITION...HIGH CLOUDS ARE MOVING NORTHWARD
NEAR THE COLORADO BORDER WHICH WILL SUPPRESS CONVECTION EVEN MORE.
KEPT POP NEAR OR BELOW 20 PERCENT FOR ISOLATED SHOWERS AND SOME
ISOLATED THUNDER AT TIMES. LOWERED POP TO AROUND 10 PERCENT IN THE
LOWER VALLEYS INTO THIS EVENING. EXPECT MOST OF THE THUNDERSTORM
ACTIVITY TO BE FURTHER NORTH AS A COOL FRONT DRIFTS SOUTHWARD AND
STALLS ACROSS CENTRAL WYOMING.

MODELS CONTINUE TO SHOW A CHANGE IN THE OVERALL PATTERN ACROSS THE
ROCKY MOUNTAIN REGION FOR FRIDAY AND THIS WEEKEND. ALL MODELS
INDICATE A PRETTY STRONG COLD FRONT FOR THIS TIME OF THE YEAR
PUSHING SOUTHWARD INTO SOUTHEAST WYOMING. THIS FRONT WILL STALL
SOMETIME ON FRIDAY AS A WAVE OF LOW PRESSURE DEVELOPS ALONG THE
FRONT...AND WILL BE THE MAIN FOCUS FOR SCATTERED TO NUMEROUS SHOWERS
AND TSTORMS AS AN UPPER LEVEL TROUGH FROM WESTERN CANADA MOVE
SOUTH AND EVENTUALLY EASTWARD INTO IDAHO. THE MAIN FORECAST
CONCERN FOR FRIDAY AND FRIDAY NIGHT IS THE POTENTIAL FOR A STEADY
HEAVY RAINFALL AS AN UPPER LEVEL TROUGH NEAR THE SOUTHERN CALIF
COASTLINE EJECTS NORTHEASTWARD ACROSS THE AREA. THE ECMWF AND NAM
ARE THE MOST AGGRESSIVE WITH THE FEATURE SHOWING WIDESPREAD
SHOWERS AND NUMEROUS TSTORMS DEVELOPING ACROSS COLORADO AND
QUICKLY MOVING NORTHWARD INTO THE FORECAST AREA. THE GFS IS THE
LEAST AGGRESSIVE AND SHOWS THE TROUGH MUCH WEAKER AS IT LIFT
NORTHEAST...AND IS BARELY NOTICEABLE BY LATE FRIDAY ACROSS THE
PLAINS. INCREASED POP UP TO 65 PERCENT ACROSS THE HIGH
PLAINS...MOSTLY OVER FAR EASTERN WYOMING AND WESTERN NEBRASKA.
RAIN SHOWERS AND EVEN ISOLATED TSTORMS MAY CONTINUE WELL INTO THE
OVERNIGHT HOURS INTO EARLY SATURDAY MORNING.

FOR SATURDAY...MODELS SHOW A BRIEF BREAK IN THE ACTION BY MID TO
LATE MORNING AS REMNANT SHOWER ACTIVITY MOVES INTO THE DAKOTAS.
SHOWER AND TSTORMS WILL QUICKLY REDEVELOP FURTHER WEST ACROSS
WYOMING/UTAH AND NORTHWEST COLORADO AS THE MAIN COLD FRONT AND
PRETTY STRONG UPPER LEVEL TROUGH MOVES EASTWARD FROM IDAHO INTO
WYOMING. EXPECT ANOTHER ROUND OF SHOWERS AND TSTORMS AHEAD AND
ALONG THIS FRONT...WHICH SOME DECENT RAINFALL AMOUNTS POSSIBLE.
INCREASED POP BETWEEN 40 TO 60 PERCENT ACROSS MOST AREAS SATURDAY
AFTERNOON AND EVENING. CLEARING SKIES ARE EXPECTED AFTER MIDNIGHT
ACROSS SOUTHEAST WYOMING WITH MUCH COOLER TEMPERATURES. A FEW
SHELTERED VALLEYS MAY LOWER INTO THE 30S SATURDAY NIGHT WITH
NEAR FREEZING TEMPERATURES IN THE MOUNTAINS.

.LONG TERM...(SUNDAY THROUGH THURSDAY)
ISSUED AT 330 PM MDT THU AUG 21 2014

MODELS VERY SIMILAR ON MOVEMENT OF UPPER LOW INTO WESTERN MONTANA
EARLY SUNDAY. SUNDAY COULD BE A PRETTY BREEZY DAY AS THE LOW
PLACEMENT IN A FAVORABLE POSITION FOR STRONG WINDS. IN FACT...THE
ECMWF 700MB WINDS ACROSS SOUTHEAST WYOMING ARE APPROACHING
40KTS...GFS A LITTLE LIGHTER WITH 30-35KTS. SHOULD NOT BE MUCH IN
THE WAY OF SHOWER ACTIVITY WITH DOWNSLOPING WINDS OFF THE LARAMIE
RANGE.

NEXT SHORTWAVE TO IMPACT THE AREA COMES IN FROM THE NORTHWEST
AROUND THAT LOW MONDAY AFTERNOON. BOTH THE GFS AND ECMWF SHOWING
MOUNTAIN SHOWERS INITIALLY. THE ECMWF IS FORECASTING A MORE
WIDESPREAD SHOWERY EVENT...THOUGH GFS DOES SHOW AN INCREASE IN
COVERAGE MONDAY NIGHT. PRETTY MUCH KEPT WHAT WE HAD GOING FOR POPS
MONDAY WITH BEST CHANCES IN THE MOUNTAINS.

DISCREPANCIES BEGIN TO INCREASE AFTER THIS SHORTWAVE AS THE ECMWF
SLOWER IN MOVING OUT THIS TROUGH. BY TUESDAY AFTERNOON...THE ECMWF
SHOWS THE UPPER TROUGH AXIS OVER EXTREME EASTERN WYOMING AND THE
GFS HAS IT ALREADY MOVING INTO CENTRAL NEBRASKA. WITH THE SLOWER
ECMWF...WE REALLY BEGIN TO SEE THE DISCREPANCIES ARISE IN 700MB
TEMPERATURES. GFS FORECASTING +4 TO +8C OVER THE CWFA WITH THE
ECMWF SHOWING +10 TO +12C. DID BEGIN TO GO LOWER ON TEMPERATURES
MORE IN LINE WITH THE GFS. UNDERCUT EXTENDED PROCEDURE GUIDANCE BY
3-4 DEGREES TO COME MORE IN LINE WITH THE GFS/MEX GUIDANCE.
LOOKS FAIRY DRY WEDNESDAY AFTERNOON AND INTO THURSDAY WITH THE
TROUGH MOVING OFF TO THE EAST.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY AFTERNOON)
ISSUED AT 535 PM MDT THU AUG 21 2014

VFR CONDITIONS SHOULD BE THE RULE FOR ALL TERMINALS THROUGH MOST
OF THE TAF PERIOD. ISOLATED TO SCATTERED SHOWERS AND TSTMS WILL
PERSIST THROUGH MID EVE ACROSS SOUTHEAST WY AND THE WESTERN NE
PANHANDLE. MAINTAINED VCTS AT KRWL...KCYS AND KBFF AS THESE ARE
THE MOST LIKELY AREAS TO SEE CONVECTION THROUGH 03Z FRI. BRIEF
MVFR VSBYS AND GUSTY WINDS MAY ACCOMPANY SOME STORMS. OTHERWISE
SKIES WILL REMAIN BKN-TO-OVC ABOVE 10K FEET AGL. FRI AFTN WILL
FEATURE LOWERING CLOUD BASES AND ANOTHER ROUND OF SHOWERS AND
TSTMS. SOME STORMS COULD BE STRONG.

&&

.FIRE WEATHER...
ISSUED AT 205 PM MDT THU AUG 21 2014

MINIMAL FIRE WEATHER CONCERNS THROUGH EARLY NEXT WEEK.
SUBTROPICAL MOISTURE WILL REMAIN OVER THE AREA THROUGH THE WEEKEND
WITH SHOWERS AND THUNDERSTORMS POSSIBLE EACH DAY ACROSS SOUTHEAST
WYOMING AND WESTERN NEBRASKA. THERE IS A GOOD CHANCE OF WETTING
RAINS ON FRIDAY THROUGH THIS WEEKEND AS SHOWERS AND THUNDERSTORM
COVERAGE WILL BE HIGHER. TEMPERATURES WILL TREND COOLER INTO THIS
WEEKEND AS A STRONG COLD FRONT FOR THIS TIME OF THE YEAR MOVES
INTO THE REGION LATE ON SATURDAY. THIS UNSETTLED WEATHER IS
EXPECTED TO CONTINUE INTO EARLY NEXT WEEK.

&&

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

$$

SHORT TERM...TJT
LONG TERM...CLAYCOMB
AVIATION...HAMMER
FIRE WEATHER...TJT








000
FXUS65 KCYS 212341
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
541 PM MDT THU AUG 21 2014

.SHORT TERM...(THIS EVENING THROUGH SATURDAY NIGHT)
ISSUED AT 300 PM MDT THU AUG 21 2014

CURRENT KCYS RADAR LOOP SHOWS A FEW SHOWERS ACROSS THE AREA AND NO
THUNDERSTORMS AT THIS TIME...WHICH WAS EXPECTED DUE TO INCREASED
SUBSIDENCE ALOFT. IN ADDITION...HIGH CLOUDS ARE MOVING NORTHWARD
NEAR THE COLORADO BORDER WHICH WILL SUPPRESS CONVECTION EVEN MORE.
KEPT POP NEAR OR BELOW 20 PERCENT FOR ISOLATED SHOWERS AND SOME
ISOLATED THUNDER AT TIMES. LOWERED POP TO AROUND 10 PERCENT IN THE
LOWER VALLEYS INTO THIS EVENING. EXPECT MOST OF THE THUNDERSTORM
ACTIVITY TO BE FURTHER NORTH AS A COOL FRONT DRIFTS SOUTHWARD AND
STALLS ACROSS CENTRAL WYOMING.

MODELS CONTINUE TO SHOW A CHANGE IN THE OVERALL PATTERN ACROSS THE
ROCKY MOUNTAIN REGION FOR FRIDAY AND THIS WEEKEND. ALL MODELS
INDICATE A PRETTY STRONG COLD FRONT FOR THIS TIME OF THE YEAR
PUSHING SOUTHWARD INTO SOUTHEAST WYOMING. THIS FRONT WILL STALL
SOMETIME ON FRIDAY AS A WAVE OF LOW PRESSURE DEVELOPS ALONG THE
FRONT...AND WILL BE THE MAIN FOCUS FOR SCATTERED TO NUMEROUS SHOWERS
AND TSTORMS AS AN UPPER LEVEL TROUGH FROM WESTERN CANADA MOVE
SOUTH AND EVENTUALLY EASTWARD INTO IDAHO. THE MAIN FORECAST
CONCERN FOR FRIDAY AND FRIDAY NIGHT IS THE POTENTIAL FOR A STEADY
HEAVY RAINFALL AS AN UPPER LEVEL TROUGH NEAR THE SOUTHERN CALIF
COASTLINE EJECTS NORTHEASTWARD ACROSS THE AREA. THE ECMWF AND NAM
ARE THE MOST AGGRESSIVE WITH THE FEATURE SHOWING WIDESPREAD
SHOWERS AND NUMEROUS TSTORMS DEVELOPING ACROSS COLORADO AND
QUICKLY MOVING NORTHWARD INTO THE FORECAST AREA. THE GFS IS THE
LEAST AGGRESSIVE AND SHOWS THE TROUGH MUCH WEAKER AS IT LIFT
NORTHEAST...AND IS BARELY NOTICEABLE BY LATE FRIDAY ACROSS THE
PLAINS. INCREASED POP UP TO 65 PERCENT ACROSS THE HIGH
PLAINS...MOSTLY OVER FAR EASTERN WYOMING AND WESTERN NEBRASKA.
RAIN SHOWERS AND EVEN ISOLATED TSTORMS MAY CONTINUE WELL INTO THE
OVERNIGHT HOURS INTO EARLY SATURDAY MORNING.

FOR SATURDAY...MODELS SHOW A BRIEF BREAK IN THE ACTION BY MID TO
LATE MORNING AS REMNANT SHOWER ACTIVITY MOVES INTO THE DAKOTAS.
SHOWER AND TSTORMS WILL QUICKLY REDEVELOP FURTHER WEST ACROSS
WYOMING/UTAH AND NORTHWEST COLORADO AS THE MAIN COLD FRONT AND
PRETTY STRONG UPPER LEVEL TROUGH MOVES EASTWARD FROM IDAHO INTO
WYOMING. EXPECT ANOTHER ROUND OF SHOWERS AND TSTORMS AHEAD AND
ALONG THIS FRONT...WHICH SOME DECENT RAINFALL AMOUNTS POSSIBLE.
INCREASED POP BETWEEN 40 TO 60 PERCENT ACROSS MOST AREAS SATURDAY
AFTERNOON AND EVENING. CLEARING SKIES ARE EXPECTED AFTER MIDNIGHT
ACROSS SOUTHEAST WYOMING WITH MUCH COOLER TEMPERATURES. A FEW
SHELTERED VALLEYS MAY LOWER INTO THE 30S SATURDAY NIGHT WITH
NEAR FREEZING TEMPERATURES IN THE MOUNTAINS.

.LONG TERM...(SUNDAY THROUGH THURSDAY)
ISSUED AT 330 PM MDT THU AUG 21 2014

MODELS VERY SIMILAR ON MOVEMENT OF UPPER LOW INTO WESTERN MONTANA
EARLY SUNDAY. SUNDAY COULD BE A PRETTY BREEZY DAY AS THE LOW
PLACEMENT IN A FAVORABLE POSITION FOR STRONG WINDS. IN FACT...THE
ECMWF 700MB WINDS ACROSS SOUTHEAST WYOMING ARE APPROACHING
40KTS...GFS A LITTLE LIGHTER WITH 30-35KTS. SHOULD NOT BE MUCH IN
THE WAY OF SHOWER ACTIVITY WITH DOWNSLOPING WINDS OFF THE LARAMIE
RANGE.

NEXT SHORTWAVE TO IMPACT THE AREA COMES IN FROM THE NORTHWEST
AROUND THAT LOW MONDAY AFTERNOON. BOTH THE GFS AND ECMWF SHOWING
MOUNTAIN SHOWERS INITIALLY. THE ECMWF IS FORECASTING A MORE
WIDESPREAD SHOWERY EVENT...THOUGH GFS DOES SHOW AN INCREASE IN
COVERAGE MONDAY NIGHT. PRETTY MUCH KEPT WHAT WE HAD GOING FOR POPS
MONDAY WITH BEST CHANCES IN THE MOUNTAINS.

DISCREPANCIES BEGIN TO INCREASE AFTER THIS SHORTWAVE AS THE ECMWF
SLOWER IN MOVING OUT THIS TROUGH. BY TUESDAY AFTERNOON...THE ECMWF
SHOWS THE UPPER TROUGH AXIS OVER EXTREME EASTERN WYOMING AND THE
GFS HAS IT ALREADY MOVING INTO CENTRAL NEBRASKA. WITH THE SLOWER
ECMWF...WE REALLY BEGIN TO SEE THE DISCREPANCIES ARISE IN 700MB
TEMPERATURES. GFS FORECASTING +4 TO +8C OVER THE CWFA WITH THE
ECMWF SHOWING +10 TO +12C. DID BEGIN TO GO LOWER ON TEMPERATURES
MORE IN LINE WITH THE GFS. UNDERCUT EXTENDED PROCEDURE GUIDANCE BY
3-4 DEGREES TO COME MORE IN LINE WITH THE GFS/MEX GUIDANCE.
LOOKS FAIRY DRY WEDNESDAY AFTERNOON AND INTO THURSDAY WITH THE
TROUGH MOVING OFF TO THE EAST.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY AFTERNOON)
ISSUED AT 535 PM MDT THU AUG 21 2014

VFR CONDITIONS SHOULD BE THE RULE FOR ALL TERMINALS THROUGH MOST
OF THE TAF PERIOD. ISOLATED TO SCATTERED SHOWERS AND TSTMS WILL
PERSIST THROUGH MID EVE ACROSS SOUTHEAST WY AND THE WESTERN NE
PANHANDLE. MAINTAINED VCTS AT KRWL...KCYS AND KBFF AS THESE ARE
THE MOST LIKELY AREAS TO SEE CONVECTION THROUGH 03Z FRI. BRIEF
MVFR VSBYS AND GUSTY WINDS MAY ACCOMPANY SOME STORMS. OTHERWISE
SKIES WILL REMAIN BKN-TO-OVC ABOVE 10K FEET AGL. FRI AFTN WILL
FEATURE LOWERING CLOUD BASES AND ANOTHER ROUND OF SHOWERS AND
TSTMS. SOME STORMS COULD BE STRONG.

&&

.FIRE WEATHER...
ISSUED AT 205 PM MDT THU AUG 21 2014

MINIMAL FIRE WEATHER CONCERNS THROUGH EARLY NEXT WEEK.
SUBTROPICAL MOISTURE WILL REMAIN OVER THE AREA THROUGH THE WEEKEND
WITH SHOWERS AND THUNDERSTORMS POSSIBLE EACH DAY ACROSS SOUTHEAST
WYOMING AND WESTERN NEBRASKA. THERE IS A GOOD CHANCE OF WETTING
RAINS ON FRIDAY THROUGH THIS WEEKEND AS SHOWERS AND THUNDERSTORM
COVERAGE WILL BE HIGHER. TEMPERATURES WILL TREND COOLER INTO THIS
WEEKEND AS A STRONG COLD FRONT FOR THIS TIME OF THE YEAR MOVES
INTO THE REGION LATE ON SATURDAY. THIS UNSETTLED WEATHER IS
EXPECTED TO CONTINUE INTO EARLY NEXT WEEK.

&&

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

$$

SHORT TERM...TJT
LONG TERM...CLAYCOMB
AVIATION...HAMMER
FIRE WEATHER...TJT







000
FXUS65 KCYS 212101
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
301 PM MDT THU AUG 21 2014

.SHORT TERM...(THIS EVENING THROUGH SATURDAY NIGHT)
ISSUED AT 300 PM MDT THU AUG 21 2014

CURRENT KCYS RADAR LOOP SHOWS A FEW SHOWERS ACROSS THE AREA AND NO
THUNDERSTORMS AT THIS TIME...WHICH WAS EXPECTED DUE TO INCREASED
SUBSIDENCE ALOFT. IN ADDITION...HIGH CLOUDS ARE MOVING NORTHWARD
NEAR THE COLORADO BORDER WHICH WILL SUPPRESS CONVECTION EVEN MORE.
KEPT POP NEAR OR BELOW 20 PERCENT FOR ISOLATED SHOWERS AND SOME
ISOLATED THUNDER AT TIMES. LOWERED POP TO AROUND 10 PERCENT IN THE
LOWER VALLEYS INTO THIS EVENING. EXPECT MOST OF THE THUNDERSTORM
ACTIVITY TO BE FURTHER NORTH AS A COOL FRONT DRIFTS SOUTHWARD AND
STALLS ACROSS CENTRAL WYOMING.

MODELS CONTINUE TO SHOW A CHANGE IN THE OVERALL PATTERN ACROSS THE
ROCKY MOUNTAIN REGION FOR FRIDAY AND THIS WEEKEND. ALL MODELS
INDICATE A PRETTY STRONG COLD FRONT FOR THIS TIME OF THE YEAR
PUSHING SOUTHWARD INTO SOUTHEAST WYOMING. THIS FRONT WILL STALL
SOMETIME ON FRIDAY AS A WAVE OF LOW PRESSURE DEVELOPS ALONG THE
FRONT...AND WILL BE THE MAIN FOCUS FOR SCATTERED TO NUMEROUS SHOWERS
AND TSTORMS AS AN UPPER LEVEL TROUGH FROM WESTERN CANADA MOVE
SOUTH AND EVENTUALLY EASTWARD INTO IDAHO. THE MAIN FORECAST
CONCERN FOR FRIDAY AND FRIDAY NIGHT IS THE POTENTIAL FOR A STEADY
HEAVY RAINFALL AS AN UPPER LEVEL TROUGH NEAR THE SOUTHERN CALIF
COASTLINE EJECTS NORTHEASTWARD ACROSS THE AREA. THE ECMWF AND NAM
ARE THE MOST AGGRESSIVE WITH THE FEATURE SHOWING WIDESPREAD
SHOWERS AND NUMEROUS TSTORMS DEVELOPING ACROSS COLORADO AND
QUICKLY MOVING NORTHWARD INTO THE FORECAST AREA. THE GFS IS THE
LEAST AGGRESSIVE AND SHOWS THE TROUGH MUCH WEAKER AS IT LIFT
NORTHEAST...AND IS BARELY NOTICEABLE BY LATE FRIDAY ACROSS THE
PLAINS. INCREASED POP UP TO 65 PERCENT ACROSS THE HIGH
PLAINS...MOSTLY OVER FAR EASTERN WYOMING AND WESTERN NEBRASKA.
RAIN SHOWERS AND EVEN ISOLATED TSTORMS MAY CONTINUE WELL INTO THE
OVERNIGHT HOURS INTO EARLY SATURDAY MORNING.

FOR SATURDAY...MODELS SHOW A BRIEF BREAK IN THE ACTION BY MID TO
LATE MORNING AS REMNANT SHOWER ACTIVITY MOVES INTO THE DAKOTAS.
SHOWER AND TSTORMS WILL QUICKLY REDEVELOP FURTHER WEST ACROSS
WYOMING/UTAH AND NORTHWEST COLORADO AS THE MAIN COLD FRONT AND
PRETTY STRONG UPPER LEVEL TROUGH MOVES EASTWARD FROM IDAHO INTO
WYOMING. EXPECT ANOTHER ROUND OF SHOWERS AND TSTORMS AHEAD AND
ALONG THIS FRONT...WHICH SOME DECENT RAINFALL AMOUNTS POSSIBLE.
INCREASED POP BETWEEN 40 TO 60 PERCENT ACROSS MOST AREAS SATURDAY
AFTERNOON AND EVENING. CLEARING SKIES ARE EXPECTED AFTER MIDNIGHT
ACROSS SOUTHEAST WYOMING WITH MUCH COOLER TEMPERATURES. A FEW
SHELTERED VALLEYS MAY LOWER INTO THE 30S SATURDAY NIGHT WITH
NEAR FREEZING TEMPERATURES IN THE MOUNTAINS.

.LONG TERM...(SUNDAY THROUGH THURSDAY)
ISSUED AT 330 PM MDT THU AUG 21 2014

MODELS VERY SIMILAR ON MOVEMENT OF UPPER LOW INTO WESTERN MONTANA
EARLY SUNDAY. SUNDAY COULD BE A PRETTY BREEZY DAY AS THE LOW
PLACEMENT IN A FAVORABLE POSITION FOR STRONG WINDS. IN FACT...THE
ECMWF 700MB WINDS ACROSS SOUTHEAST WYOMING ARE APPROACHING
40KTS...GFS A LITTLE LIGHTER WITH 30-35KTS. SHOULD NOT BE MUCH IN
THE WAY OF SHOWER ACTIVITY WITH DOWNSLOPING WINDS OFF THE LARAMIE
RANGE.

NEXT SHORTWAVE TO IMPACT THE AREA COMES IN FROM THE NORTHWEST
AROUND THAT LOW MONDAY AFTERNOON. BOTH THE GFS AND ECMWF SHOWING
MOUNTAIN SHOWERS INITIALLY. THE ECMWF IS FORECASTING A MORE
WIDESPREAD SHOWERY EVENT...THOUGH GFS DOES SHOW AN INCREASE IN
COVERAGE MONDAY NIGHT. PRETTY MUCH KEPT WHAT WE HAD GOING FOR POPS
MONDAY WITH BEST CHANCES IN THE MOUNTAINS.

DISCREPANCIES BEGIN TO INCREASE AFTER THIS SHORTWAVE AS THE ECMWF
SLOWER IN MOVING OUT THIS TROUGH. BY TUESDAY AFTERNOON...THE ECMWF
SHOWS THE UPPER TROUGH AXIS OVER EXTREME EASTERN WYOMING AND THE
GFS HAS IT ALREADY MOVING INTO CENTRAL NEBRASKA. WITH THE SLOWER
ECMWF...WE REALLY BEGIN TO SEE THE DISCREPANCIES ARISE IN 700MB
TEMPERATURES. GFS FORECASTING +4 TO +8C OVER THE CWFA WITH THE
ECMWF SHOWING +10 TO +12C. DID BEGIN TO GO LOWER ON TEMPERATURES
MORE IN LINE WITH THE GFS. UNDERCUT EXTENDED PROCEDURE GUIDANCE BY
3-4 DEGREES TO COME MORE IN LINE WITH THE GFS/MEX GUIDANCE.
LOOKS FAIRY DRY WEDNESDAY AFTERNOON AND INTO THURSDAY WITH THE
TROUGH MOVING OFF TO THE EAST.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY MORNING)
ISSUED AT 1039 AM MDT THU AUG 21 2014

CONVECTION LOOKS TO BE CONFINED TO EXTREME SOUTHERN WYOMING AND
THE SOUTHERN NEBRASKA PANHANDLE TODAY. USED TIMING FROM LATEST
HRRR FORECAST THAT SHOWS KCYS AND POSSIBLY KBFF AND KSNY SEEING SOME
CONVECTION LATE THIS AFTERNOON. VFR CONDITIONS OTHERWISE OUTSIDE
OF THUNDERSTORMS.

&&

.FIRE WEATHER...
ISSUED AT 205 PM MDT THU AUG 21 2014

MINIMAL FIRE WEATHER CONCERNS THROUGH EARLY NEXT WEEK.
SUBTROPICAL MOISTURE WILL REMAIN OVER THE AREA THROUGH THE WEEKEND
WITH SHOWERS AND THUNDERSTORMS POSSIBLE EACH DAY ACROSS SOUTHEAST
WYOMING AND WESTERN NEBRASKA. THERE IS A GOOD CHANCE OF WETTING
RAINS ON FRIDAY THROUGH THIS WEEKEND AS SHOWERS AND THUNDERSTORM
COVERAGE WILL BE HIGHER. TEMPERATURES WILL TREND COOLER INTO THIS
WEEKEND AS A STRONG COLD FRONT FOR THIS TIME OF THE YEAR MOVES
INTO THE REGION LATE ON SATURDAY. THIS UNSETTLED WEATHER IS
EXPECTED TO CONTINUE INTO EARLY NEXT WEEK.

&&

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

$$

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











000
FXUS65 KCYS 212101
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
301 PM MDT THU AUG 21 2014

.SHORT TERM...(THIS EVENING THROUGH SATURDAY NIGHT)
ISSUED AT 300 PM MDT THU AUG 21 2014

CURRENT KCYS RADAR LOOP SHOWS A FEW SHOWERS ACROSS THE AREA AND NO
THUNDERSTORMS AT THIS TIME...WHICH WAS EXPECTED DUE TO INCREASED
SUBSIDENCE ALOFT. IN ADDITION...HIGH CLOUDS ARE MOVING NORTHWARD
NEAR THE COLORADO BORDER WHICH WILL SUPPRESS CONVECTION EVEN MORE.
KEPT POP NEAR OR BELOW 20 PERCENT FOR ISOLATED SHOWERS AND SOME
ISOLATED THUNDER AT TIMES. LOWERED POP TO AROUND 10 PERCENT IN THE
LOWER VALLEYS INTO THIS EVENING. EXPECT MOST OF THE THUNDERSTORM
ACTIVITY TO BE FURTHER NORTH AS A COOL FRONT DRIFTS SOUTHWARD AND
STALLS ACROSS CENTRAL WYOMING.

MODELS CONTINUE TO SHOW A CHANGE IN THE OVERALL PATTERN ACROSS THE
ROCKY MOUNTAIN REGION FOR FRIDAY AND THIS WEEKEND. ALL MODELS
INDICATE A PRETTY STRONG COLD FRONT FOR THIS TIME OF THE YEAR
PUSHING SOUTHWARD INTO SOUTHEAST WYOMING. THIS FRONT WILL STALL
SOMETIME ON FRIDAY AS A WAVE OF LOW PRESSURE DEVELOPS ALONG THE
FRONT...AND WILL BE THE MAIN FOCUS FOR SCATTERED TO NUMEROUS SHOWERS
AND TSTORMS AS AN UPPER LEVEL TROUGH FROM WESTERN CANADA MOVE
SOUTH AND EVENTUALLY EASTWARD INTO IDAHO. THE MAIN FORECAST
CONCERN FOR FRIDAY AND FRIDAY NIGHT IS THE POTENTIAL FOR A STEADY
HEAVY RAINFALL AS AN UPPER LEVEL TROUGH NEAR THE SOUTHERN CALIF
COASTLINE EJECTS NORTHEASTWARD ACROSS THE AREA. THE ECMWF AND NAM
ARE THE MOST AGGRESSIVE WITH THE FEATURE SHOWING WIDESPREAD
SHOWERS AND NUMEROUS TSTORMS DEVELOPING ACROSS COLORADO AND
QUICKLY MOVING NORTHWARD INTO THE FORECAST AREA. THE GFS IS THE
LEAST AGGRESSIVE AND SHOWS THE TROUGH MUCH WEAKER AS IT LIFT
NORTHEAST...AND IS BARELY NOTICEABLE BY LATE FRIDAY ACROSS THE
PLAINS. INCREASED POP UP TO 65 PERCENT ACROSS THE HIGH
PLAINS...MOSTLY OVER FAR EASTERN WYOMING AND WESTERN NEBRASKA.
RAIN SHOWERS AND EVEN ISOLATED TSTORMS MAY CONTINUE WELL INTO THE
OVERNIGHT HOURS INTO EARLY SATURDAY MORNING.

FOR SATURDAY...MODELS SHOW A BRIEF BREAK IN THE ACTION BY MID TO
LATE MORNING AS REMNANT SHOWER ACTIVITY MOVES INTO THE DAKOTAS.
SHOWER AND TSTORMS WILL QUICKLY REDEVELOP FURTHER WEST ACROSS
WYOMING/UTAH AND NORTHWEST COLORADO AS THE MAIN COLD FRONT AND
PRETTY STRONG UPPER LEVEL TROUGH MOVES EASTWARD FROM IDAHO INTO
WYOMING. EXPECT ANOTHER ROUND OF SHOWERS AND TSTORMS AHEAD AND
ALONG THIS FRONT...WHICH SOME DECENT RAINFALL AMOUNTS POSSIBLE.
INCREASED POP BETWEEN 40 TO 60 PERCENT ACROSS MOST AREAS SATURDAY
AFTERNOON AND EVENING. CLEARING SKIES ARE EXPECTED AFTER MIDNIGHT
ACROSS SOUTHEAST WYOMING WITH MUCH COOLER TEMPERATURES. A FEW
SHELTERED VALLEYS MAY LOWER INTO THE 30S SATURDAY NIGHT WITH
NEAR FREEZING TEMPERATURES IN THE MOUNTAINS.

.LONG TERM...(SUNDAY THROUGH THURSDAY)
ISSUED AT 330 PM MDT THU AUG 21 2014

MODELS VERY SIMILAR ON MOVEMENT OF UPPER LOW INTO WESTERN MONTANA
EARLY SUNDAY. SUNDAY COULD BE A PRETTY BREEZY DAY AS THE LOW
PLACEMENT IN A FAVORABLE POSITION FOR STRONG WINDS. IN FACT...THE
ECMWF 700MB WINDS ACROSS SOUTHEAST WYOMING ARE APPROACHING
40KTS...GFS A LITTLE LIGHTER WITH 30-35KTS. SHOULD NOT BE MUCH IN
THE WAY OF SHOWER ACTIVITY WITH DOWNSLOPING WINDS OFF THE LARAMIE
RANGE.

NEXT SHORTWAVE TO IMPACT THE AREA COMES IN FROM THE NORTHWEST
AROUND THAT LOW MONDAY AFTERNOON. BOTH THE GFS AND ECMWF SHOWING
MOUNTAIN SHOWERS INITIALLY. THE ECMWF IS FORECASTING A MORE
WIDESPREAD SHOWERY EVENT...THOUGH GFS DOES SHOW AN INCREASE IN
COVERAGE MONDAY NIGHT. PRETTY MUCH KEPT WHAT WE HAD GOING FOR POPS
MONDAY WITH BEST CHANCES IN THE MOUNTAINS.

DISCREPANCIES BEGIN TO INCREASE AFTER THIS SHORTWAVE AS THE ECMWF
SLOWER IN MOVING OUT THIS TROUGH. BY TUESDAY AFTERNOON...THE ECMWF
SHOWS THE UPPER TROUGH AXIS OVER EXTREME EASTERN WYOMING AND THE
GFS HAS IT ALREADY MOVING INTO CENTRAL NEBRASKA. WITH THE SLOWER
ECMWF...WE REALLY BEGIN TO SEE THE DISCREPANCIES ARISE IN 700MB
TEMPERATURES. GFS FORECASTING +4 TO +8C OVER THE CWFA WITH THE
ECMWF SHOWING +10 TO +12C. DID BEGIN TO GO LOWER ON TEMPERATURES
MORE IN LINE WITH THE GFS. UNDERCUT EXTENDED PROCEDURE GUIDANCE BY
3-4 DEGREES TO COME MORE IN LINE WITH THE GFS/MEX GUIDANCE.
LOOKS FAIRY DRY WEDNESDAY AFTERNOON AND INTO THURSDAY WITH THE
TROUGH MOVING OFF TO THE EAST.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY MORNING)
ISSUED AT 1039 AM MDT THU AUG 21 2014

CONVECTION LOOKS TO BE CONFINED TO EXTREME SOUTHERN WYOMING AND
THE SOUTHERN NEBRASKA PANHANDLE TODAY. USED TIMING FROM LATEST
HRRR FORECAST THAT SHOWS KCYS AND POSSIBLY KBFF AND KSNY SEEING SOME
CONVECTION LATE THIS AFTERNOON. VFR CONDITIONS OTHERWISE OUTSIDE
OF THUNDERSTORMS.

&&

.FIRE WEATHER...
ISSUED AT 205 PM MDT THU AUG 21 2014

MINIMAL FIRE WEATHER CONCERNS THROUGH EARLY NEXT WEEK.
SUBTROPICAL MOISTURE WILL REMAIN OVER THE AREA THROUGH THE WEEKEND
WITH SHOWERS AND THUNDERSTORMS POSSIBLE EACH DAY ACROSS SOUTHEAST
WYOMING AND WESTERN NEBRASKA. THERE IS A GOOD CHANCE OF WETTING
RAINS ON FRIDAY THROUGH THIS WEEKEND AS SHOWERS AND THUNDERSTORM
COVERAGE WILL BE HIGHER. TEMPERATURES WILL TREND COOLER INTO THIS
WEEKEND AS A STRONG COLD FRONT FOR THIS TIME OF THE YEAR MOVES
INTO THE REGION LATE ON SATURDAY. THIS UNSETTLED WEATHER IS
EXPECTED TO CONTINUE INTO EARLY NEXT WEEK.

&&

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

$$

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










000
FXUS65 KCYS 211642
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
1042 AM MDT THU AUG 21 2014

.UPDATE...
ISSUED AT 908 AM MDT THU AUG 21 2014

CURRENT FORECAST FOR TODAY LOOKS ON TRACK. MADE SOME MINOR
ADJUSTMENTS TO PRECIP PROBABILITIES AND TSTORM COVERAGE TODAY.
CONVECTION WILL STRUGGLE TO DEVELOP THIS AFTERNOON FURTHER SOUTH
DUE TO SUBSIDENCE AND DRIER AIR ALOFT. HOWEVER...MODEL SOUNDINGS
SHOW THIS WARM/DRY LAYER ALOFT ERODING BY THIS EVENING. CAN NOT
RULE OUT AN ISOLATED SHOWER OR THUNDERSHOWER ALONG I80 LATE THIS
AFTERNOON AND THIS EVENING AS A WEAK DISTURBANCE ALOFT WILL MOVE
ACROSS THE REGION. STILL EXPECT MOST OF THE ACTIVITY TO REMAIN
ACROSS CENTRAL AND NORTHEAST WYOMING AS A FRONTAL BOUNDARY
GRADUALLY DRIFTS SOUTHWARD AND STALLS ACROSS NORTH-CENTRAL WYOMING
TODAY.

&&

.SHORT TERM...(TODAY THROUGH SATURDAY NIGHT)
ISSUED AT 426 AM MDT THU AUG 21 2014

FLOW ALOFT REMAINS SOUTHWEST. ISOLATED TO SCATTERED LATE DAY
SHOWERS AND THUNDERSTORMS ON TAP WEST OF A LARAMIE TO CHADRON LINE
WHERE MOISTURE AND INSTABILITY WILL COINCIDE ALONG WITH BEST UPPER
FORCING.

TONIGHT...COLD FRONT MOVES WEST TO EAST ACROSS THE COUNTIES WITH A
FEW SHOWERS POSSIBLE LATE NORTH OF A LUSK TO SIDNEY LINE.

FRIDAY...NEXT NEGATIVELY TILTED SHORTWAVE TROUGH ALOFT MOVES ACROSS
WESTERN COLORADO...WITH MID LEVEL SHORTWAVE TROUGH OVER NORTHERN
COLORADO COMBINED WITH ADEQUATE LOW AND MID LEVEL MOISTURE TO
PRODUCE SCATTERED LATE DAY SHOWERS AND THUNDERSTORMS...MOST
NUMEROUS EAST OF A CHEYENNE TO LUSK LINE.

FRIDAY NIGHT...SHORTWAVE TROUGH ALOFT ROTATES NORTHEAST ACROSS
EASTERN WYOMING AND WESTERN NEBRASKA...WITH AT LEAST SCATTERED
SHOWERS AND THUNDERSTORMS DEVELOPING...LIKELY MOST NUMEROUS ACROSS
WESTERN NEBRASKA.

SATURDAY...UNSETTLED PATTERN CONTINUES OVER OUR COUNTIES AS THE
DOMINANT UPPER TROUGH PREVAILS OVER MONTANA AND WYOMING...WITH THE
NEXT SHORTWAVE TROUGH ALOFT ROTATING ACROSS WESTERN WYOMING...
PRODUCING AT LEAST SCATTERED SHOWERS AND THUNDERSTORMS NEAR THE LOW
AND MID LEVEL THETA-E RIDGE AXIS.

.LONG TERM...(SUNDAY THROUGH THURSDAY)
ISSUED AT 426 AM MDT THU AUG 21 2014

00Z MEDIUM RANGE DETERMINISTIC MODELS CONTINUE TO PAINT A FAIRLY
SIMILAR PICTURE FOR SUNDAY AND MONDAY...BUT DEVIATE DRAMATICALLY
ON TUESDAY THROUGH THURSDAY. SATURDAYS FRONT WILL BE SOUTH OF THE
CWA FOR SUNDAY...WITH THE ASSOCIATED SHORTWAVE ENERGY LIFTING
NORTHEAST ACROSS THE DAKOTAS. LOOKS LIKE A RELATIVELY COOL AND
STABLE DAY SHAPING UP...WHICH WILL SUPPRESS MOST CONVECTIVE
CHANCES. THE GFS DOES PAINT SOME MOISTURE ALONG THE I80 CORRIDOR
FROM CHEYENNE TO SIDNEY AS THE WARM FRONT LIFTS BACK NORTH LATE
SUNDAY EVENING. SOUTHWEST FLOW WILL PERSIST ON MONDAY AS THE NEXT
SHORTWAVE DIVES SOUTHEAST INTO MONTANA/IDAHO. INCREASING MOISTURE
AND ASCENT WITH THE APPROACH OF THE UPSTREAM TROUGH WILL INCREASE
THUNDERSTORM CHANCES W-E MONDAY AND MONDAY NIGHT. IT AS AT THIS
TIME WHEN MODEL SOLUTIONS BEGIN TO DIVERGE. THE 00Z GFS AND
CANADIAN MAINTAIN A PROGRESSIVE PATTERN FOR THE TUE-THU TIMEFRAME.
MEANWHILE...THE STALWART ECMWF SHOWS THIS SHORTWAVE TROF BEGINNING
TO ELONGATE INTO NRN CALIFORNIA LATE MONDAY...EVENTUALLY CUTTING
OFF OVR THE GREAT BASIN MID-WEEK. THE DOWNSTREAM IMPACTS ARE
MANY...PENDING WHICH SOLUTION IS CORRECT. HAVE LARGELY DISCOUNTED
THE 00Z ECMWF GIVEN ITS DEVIATION RUN-TO-RUN AS WELL AS FROM OTHER
GLOBAL MODELS. OF COURSE...ANY ADDL SUPPORT BOTH RUN-TO-RUN OR
AMONGST OTHER GLOBAL MODELS IN FUTURE OUTPUT WOULD ADD CREDENCE TO
THIS OUTCOME. IN THE NON-ECMWF SOLUTION...ANOTHER FRONT WOULD
SLICE THRU THE CWA ON TUESDAY... USHERING THE COOLEST TEMPS OF THE
WEEK AND ANOTHER GOOD CHANCE FOR PRECIP. PRECIP WILL EXIT QUICKLY
TUE NT...WITH DRIER AND WARMER CONDITIONS EXPECTED FOR WED AND
THU.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY MORNING)
ISSUED AT 1039 AM MDT THU AUG 21 2014

CONVECTION LOOKS TO BE CONFINED TO EXTREME SOUTHERN WYOMING AND
THE SOUTHERN NEBRASKA PANHANDLE TODAY. USED TIMING FROM LATEST
HRRR FORECAST THAT SHOWS KCYS AND POSSIBLY KBFF AND KSNY SEEING SOME
CONVECTION LATE THIS AFTERNOON. VFR CONDITIONS OTHERWISE OUTSIDE
OF THUNDERSTORMS.

&&

.FIRE WEATHER...
ISSUED AT 426 AM MDT THU AUG 21 2014

MINIMAL CONCERNS AS THE WINDS AND HUMIDITIES REMAIN BELOW
CRITICAL THRESHOLDS.

&&

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

$$

UPDATE...TJT
SHORT TERM...RUBIN
LONG TERM...HAHN
AVIATION...CLAYCOMB
FIRE WEATHER...RUBIN








000
FXUS65 KCYS 211642
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
1042 AM MDT THU AUG 21 2014

.UPDATE...
ISSUED AT 908 AM MDT THU AUG 21 2014

CURRENT FORECAST FOR TODAY LOOKS ON TRACK. MADE SOME MINOR
ADJUSTMENTS TO PRECIP PROBABILITIES AND TSTORM COVERAGE TODAY.
CONVECTION WILL STRUGGLE TO DEVELOP THIS AFTERNOON FURTHER SOUTH
DUE TO SUBSIDENCE AND DRIER AIR ALOFT. HOWEVER...MODEL SOUNDINGS
SHOW THIS WARM/DRY LAYER ALOFT ERODING BY THIS EVENING. CAN NOT
RULE OUT AN ISOLATED SHOWER OR THUNDERSHOWER ALONG I80 LATE THIS
AFTERNOON AND THIS EVENING AS A WEAK DISTURBANCE ALOFT WILL MOVE
ACROSS THE REGION. STILL EXPECT MOST OF THE ACTIVITY TO REMAIN
ACROSS CENTRAL AND NORTHEAST WYOMING AS A FRONTAL BOUNDARY
GRADUALLY DRIFTS SOUTHWARD AND STALLS ACROSS NORTH-CENTRAL WYOMING
TODAY.

&&

.SHORT TERM...(TODAY THROUGH SATURDAY NIGHT)
ISSUED AT 426 AM MDT THU AUG 21 2014

FLOW ALOFT REMAINS SOUTHWEST. ISOLATED TO SCATTERED LATE DAY
SHOWERS AND THUNDERSTORMS ON TAP WEST OF A LARAMIE TO CHADRON LINE
WHERE MOISTURE AND INSTABILITY WILL COINCIDE ALONG WITH BEST UPPER
FORCING.

TONIGHT...COLD FRONT MOVES WEST TO EAST ACROSS THE COUNTIES WITH A
FEW SHOWERS POSSIBLE LATE NORTH OF A LUSK TO SIDNEY LINE.

FRIDAY...NEXT NEGATIVELY TILTED SHORTWAVE TROUGH ALOFT MOVES ACROSS
WESTERN COLORADO...WITH MID LEVEL SHORTWAVE TROUGH OVER NORTHERN
COLORADO COMBINED WITH ADEQUATE LOW AND MID LEVEL MOISTURE TO
PRODUCE SCATTERED LATE DAY SHOWERS AND THUNDERSTORMS...MOST
NUMEROUS EAST OF A CHEYENNE TO LUSK LINE.

FRIDAY NIGHT...SHORTWAVE TROUGH ALOFT ROTATES NORTHEAST ACROSS
EASTERN WYOMING AND WESTERN NEBRASKA...WITH AT LEAST SCATTERED
SHOWERS AND THUNDERSTORMS DEVELOPING...LIKELY MOST NUMEROUS ACROSS
WESTERN NEBRASKA.

SATURDAY...UNSETTLED PATTERN CONTINUES OVER OUR COUNTIES AS THE
DOMINANT UPPER TROUGH PREVAILS OVER MONTANA AND WYOMING...WITH THE
NEXT SHORTWAVE TROUGH ALOFT ROTATING ACROSS WESTERN WYOMING...
PRODUCING AT LEAST SCATTERED SHOWERS AND THUNDERSTORMS NEAR THE LOW
AND MID LEVEL THETA-E RIDGE AXIS.

.LONG TERM...(SUNDAY THROUGH THURSDAY)
ISSUED AT 426 AM MDT THU AUG 21 2014

00Z MEDIUM RANGE DETERMINISTIC MODELS CONTINUE TO PAINT A FAIRLY
SIMILAR PICTURE FOR SUNDAY AND MONDAY...BUT DEVIATE DRAMATICALLY
ON TUESDAY THROUGH THURSDAY. SATURDAYS FRONT WILL BE SOUTH OF THE
CWA FOR SUNDAY...WITH THE ASSOCIATED SHORTWAVE ENERGY LIFTING
NORTHEAST ACROSS THE DAKOTAS. LOOKS LIKE A RELATIVELY COOL AND
STABLE DAY SHAPING UP...WHICH WILL SUPPRESS MOST CONVECTIVE
CHANCES. THE GFS DOES PAINT SOME MOISTURE ALONG THE I80 CORRIDOR
FROM CHEYENNE TO SIDNEY AS THE WARM FRONT LIFTS BACK NORTH LATE
SUNDAY EVENING. SOUTHWEST FLOW WILL PERSIST ON MONDAY AS THE NEXT
SHORTWAVE DIVES SOUTHEAST INTO MONTANA/IDAHO. INCREASING MOISTURE
AND ASCENT WITH THE APPROACH OF THE UPSTREAM TROUGH WILL INCREASE
THUNDERSTORM CHANCES W-E MONDAY AND MONDAY NIGHT. IT AS AT THIS
TIME WHEN MODEL SOLUTIONS BEGIN TO DIVERGE. THE 00Z GFS AND
CANADIAN MAINTAIN A PROGRESSIVE PATTERN FOR THE TUE-THU TIMEFRAME.
MEANWHILE...THE STALWART ECMWF SHOWS THIS SHORTWAVE TROF BEGINNING
TO ELONGATE INTO NRN CALIFORNIA LATE MONDAY...EVENTUALLY CUTTING
OFF OVR THE GREAT BASIN MID-WEEK. THE DOWNSTREAM IMPACTS ARE
MANY...PENDING WHICH SOLUTION IS CORRECT. HAVE LARGELY DISCOUNTED
THE 00Z ECMWF GIVEN ITS DEVIATION RUN-TO-RUN AS WELL AS FROM OTHER
GLOBAL MODELS. OF COURSE...ANY ADDL SUPPORT BOTH RUN-TO-RUN OR
AMONGST OTHER GLOBAL MODELS IN FUTURE OUTPUT WOULD ADD CREDENCE TO
THIS OUTCOME. IN THE NON-ECMWF SOLUTION...ANOTHER FRONT WOULD
SLICE THRU THE CWA ON TUESDAY... USHERING THE COOLEST TEMPS OF THE
WEEK AND ANOTHER GOOD CHANCE FOR PRECIP. PRECIP WILL EXIT QUICKLY
TUE NT...WITH DRIER AND WARMER CONDITIONS EXPECTED FOR WED AND
THU.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY MORNING)
ISSUED AT 1039 AM MDT THU AUG 21 2014

CONVECTION LOOKS TO BE CONFINED TO EXTREME SOUTHERN WYOMING AND
THE SOUTHERN NEBRASKA PANHANDLE TODAY. USED TIMING FROM LATEST
HRRR FORECAST THAT SHOWS KCYS AND POSSIBLY KBFF AND KSNY SEEING SOME
CONVECTION LATE THIS AFTERNOON. VFR CONDITIONS OTHERWISE OUTSIDE
OF THUNDERSTORMS.

&&

.FIRE WEATHER...
ISSUED AT 426 AM MDT THU AUG 21 2014

MINIMAL CONCERNS AS THE WINDS AND HUMIDITIES REMAIN BELOW
CRITICAL THRESHOLDS.

&&

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

$$

UPDATE...TJT
SHORT TERM...RUBIN
LONG TERM...HAHN
AVIATION...CLAYCOMB
FIRE WEATHER...RUBIN







000
FXUS65 KCYS 211513
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
913 AM MDT THU AUG 21 2014

.UPDATE...
ISSUED AT 908 AM MDT THU AUG 21 2014

CURRENT FORECAST FOR TODAY LOOKS ON TRACK. MADE SOME MINOR
ADJUSTMENTS TO PRECIP PROBABILITIES AND TSTORM COVERAGE TODAY.
CONVECTION WILL STRUGGLE TO DEVELOP THIS AFTERNOON FURTHER SOUTH
DUE TO SUBSIDENCE AND DRIER AIR ALOFT. HOWEVER...MODEL SOUNDINGS
SHOW THIS WARM/DRY LAYER ALOFT ERODING BY THIS EVENING. CAN NOT
RULE OUT AN ISOLATED SHOWER OR THUNDERSHOWER ALONG I80 LATE THIS
AFTERNOON AND THIS EVENING AS A WEAK DISTURBANCE ALOFT WILL MOVE
ACROSS THE REGION. STILL EXPECT MOST OF THE ACTIVITY TO REMAIN
ACROSS CENTRAL AND NORTHEAST WYOMING AS A FRONTAL BOUNDARY
GRADUALLY DRIFTS SOUTHWARD AND STALLS ACROSS NORTH-CENTRAL WYOMING
TODAY.

&&

.SHORT TERM...(TODAY THROUGH SATURDAY NIGHT)
ISSUED AT 426 AM MDT THU AUG 21 2014

FLOW ALOFT REMAINS SOUTHWEST. ISOLATED TO SCATTERED LATE DAY
SHOWERS AND THUNDERSTORMS ON TAP WEST OF A LARAMIE TO CHADRON LINE
WHERE MOISTURE AND INSTABILITY WILL COINCIDE ALONG WITH BEST UPPER
FORCING.

TONIGHT...COLD FRONT MOVES WEST TO EAST ACROSS THE COUNTIES WITH A
FEW SHOWERS POSSIBLE LATE NORTH OF A LUSK TO SIDNEY LINE.

FRIDAY...NEXT NEGATIVELY TILTED SHORTWAVE TROUGH ALOFT MOVES ACROSS
WESTERN COLORADO...WITH MID LEVEL SHORTWAVE TROUGH OVER NORTHERN
COLORADO COMBINED WITH ADEQUATE LOW AND MID LEVEL MOISTURE TO
PRODUCE SCATTERED LATE DAY SHOWERS AND THUNDERSTORMS...MOST
NUMEROUS EAST OF A CHEYENNE TO LUSK LINE.

FRIDAY NIGHT...SHORTWAVE TROUGH ALOFT ROTATES NORTHEAST ACROSS
EASTERN WYOMING AND WESTERN NEBRASKA...WITH AT LEAST SCATTERED
SHOWERS AND THUNDERSTORMS DEVELOPING...LIKELY MOST NUMEROUS ACROSS
WESTERN NEBRASKA.

SATURDAY...UNSETTLED PATTERN CONTINUES OVER OUR COUNTIES AS THE
DOMINANT UPPER TROUGH PREVAILS OVER MONTANA AND WYOMING...WITH THE
NEXT SHORTWAVE TROUGH ALOFT ROTATING ACROSS WESTERN WYOMING...
PRODUCING AT LEAST SCATTERED SHOWERS AND THUNDERSTORMS NEAR THE LOW
AND MID LEVEL THETA-E RIDGE AXIS.

.LONG TERM...(SUNDAY THROUGH THURSDAY)
ISSUED AT 426 AM MDT THU AUG 21 2014

00Z MEDIUM RANGE DETERMINISTIC MODELS CONTINUE TO PAINT A FAIRLY
SIMILAR PICTURE FOR SUNDAY AND MONDAY...BUT DEVIATE DRAMATICALLY
ON TUESDAY THROUGH THURSDAY. SATURDAYS FRONT WILL BE SOUTH OF THE
CWA FOR SUNDAY...WITH THE ASSOCIATED SHORTWAVE ENERGY LIFTING
NORTHEAST ACROSS THE DAKOTAS. LOOKS LIKE A RELATIVELY COOL AND
STABLE DAY SHAPING UP...WHICH WILL SUPPRESS MOST CONVECTIVE
CHANCES. THE GFS DOES PAINT SOME MOISTURE ALONG THE I80 CORRIDOR
FROM CHEYENNE TO SIDNEY AS THE WARM FRONT LIFTS BACK NORTH LATE
SUNDAY EVENING. SOUTHWEST FLOW WILL PERSIST ON MONDAY AS THE NEXT
SHORTWAVE DIVES SOUTHEAST INTO MONTANA/IDAHO. INCREASING MOISTURE
AND ASCENT WITH THE APPROACH OF THE UPSTREAM TROUGH WILL INCREASE
THUNDERSTORM CHANCES W-E MONDAY AND MONDAY NIGHT. IT AS AT THIS
TIME WHEN MODEL SOLUTIONS BEGIN TO DIVERGE. THE 00Z GFS AND
CANADIAN MAINTAIN A PROGRESSIVE PATTERN FOR THE TUE-THU TIMEFRAME.
MEANWHILE...THE STALWART ECMWF SHOWS THIS SHORTWAVE TROF BEGINNING
TO ELONGATE INTO NRN CALIFORNIA LATE MONDAY...EVENTUALLY CUTTING
OFF OVR THE GREAT BASIN MID-WEEK. THE DOWNSTREAM IMPACTS ARE
MANY...PENDING WHICH SOLUTION IS CORRECT. HAVE LARGELY DISCOUNTED
THE 00Z ECMWF GIVEN ITS DEVIATION RUN-TO-RUN AS WELL AS FROM OTHER
GLOBAL MODELS. OF COURSE...ANY ADDL SUPPORT BOTH RUN-TO-RUN OR
AMONGST OTHER GLOBAL MODELS IN FUTURE OUTPUT WOULD ADD CREDENCE TO
THIS OUTCOME. IN THE NON-ECMWF SOLUTION...ANOTHER FRONT WOULD
SLICE THRU THE CWA ON TUESDAY... USHERING THE COOLEST TEMPS OF THE
WEEK AND ANOTHER GOOD CHANCE FOR PRECIP. PRECIP WILL EXIT QUICKLY
TUE NT...WITH DRIER AND WARMER CONDITIONS EXPECTED FOR WED AND
THU.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 426 AM MDT THU AUG 21 2014

VFR CONDITIONS WILL PREVAIL THROUGH THE PERIOD...AS THE AREA
REMAINS IN BETWEEN SYSTEMS. TERMINALS CAN EXPECT JUST SOME PASSING
MID/HIGH-LEVEL CLOUDS FROM TIME TO TIME. OTHERWISE...WEST WINDS
WILL GUST TO 15-25 KNOTS AT SE WYOMING SITES 16-24Z.


&&

.FIRE WEATHER...
ISSUED AT 426 AM MDT THU AUG 21 2014

MINIMAL CONCERNS AS THE WINDS AND HUMIDITIES REMAIN BELOW
CRITICAL THRESHOLDS.

&&

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

$$

UPDATE...TJT
SHORT TERM...RUBIN
LONG TERM...HAHN
AVIATION...HAHN
FIRE WEATHER...RUBIN









000
FXUS65 KCYS 211513
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
913 AM MDT THU AUG 21 2014

.UPDATE...
ISSUED AT 908 AM MDT THU AUG 21 2014

CURRENT FORECAST FOR TODAY LOOKS ON TRACK. MADE SOME MINOR
ADJUSTMENTS TO PRECIP PROBABILITIES AND TSTORM COVERAGE TODAY.
CONVECTION WILL STRUGGLE TO DEVELOP THIS AFTERNOON FURTHER SOUTH
DUE TO SUBSIDENCE AND DRIER AIR ALOFT. HOWEVER...MODEL SOUNDINGS
SHOW THIS WARM/DRY LAYER ALOFT ERODING BY THIS EVENING. CAN NOT
RULE OUT AN ISOLATED SHOWER OR THUNDERSHOWER ALONG I80 LATE THIS
AFTERNOON AND THIS EVENING AS A WEAK DISTURBANCE ALOFT WILL MOVE
ACROSS THE REGION. STILL EXPECT MOST OF THE ACTIVITY TO REMAIN
ACROSS CENTRAL AND NORTHEAST WYOMING AS A FRONTAL BOUNDARY
GRADUALLY DRIFTS SOUTHWARD AND STALLS ACROSS NORTH-CENTRAL WYOMING
TODAY.

&&

.SHORT TERM...(TODAY THROUGH SATURDAY NIGHT)
ISSUED AT 426 AM MDT THU AUG 21 2014

FLOW ALOFT REMAINS SOUTHWEST. ISOLATED TO SCATTERED LATE DAY
SHOWERS AND THUNDERSTORMS ON TAP WEST OF A LARAMIE TO CHADRON LINE
WHERE MOISTURE AND INSTABILITY WILL COINCIDE ALONG WITH BEST UPPER
FORCING.

TONIGHT...COLD FRONT MOVES WEST TO EAST ACROSS THE COUNTIES WITH A
FEW SHOWERS POSSIBLE LATE NORTH OF A LUSK TO SIDNEY LINE.

FRIDAY...NEXT NEGATIVELY TILTED SHORTWAVE TROUGH ALOFT MOVES ACROSS
WESTERN COLORADO...WITH MID LEVEL SHORTWAVE TROUGH OVER NORTHERN
COLORADO COMBINED WITH ADEQUATE LOW AND MID LEVEL MOISTURE TO
PRODUCE SCATTERED LATE DAY SHOWERS AND THUNDERSTORMS...MOST
NUMEROUS EAST OF A CHEYENNE TO LUSK LINE.

FRIDAY NIGHT...SHORTWAVE TROUGH ALOFT ROTATES NORTHEAST ACROSS
EASTERN WYOMING AND WESTERN NEBRASKA...WITH AT LEAST SCATTERED
SHOWERS AND THUNDERSTORMS DEVELOPING...LIKELY MOST NUMEROUS ACROSS
WESTERN NEBRASKA.

SATURDAY...UNSETTLED PATTERN CONTINUES OVER OUR COUNTIES AS THE
DOMINANT UPPER TROUGH PREVAILS OVER MONTANA AND WYOMING...WITH THE
NEXT SHORTWAVE TROUGH ALOFT ROTATING ACROSS WESTERN WYOMING...
PRODUCING AT LEAST SCATTERED SHOWERS AND THUNDERSTORMS NEAR THE LOW
AND MID LEVEL THETA-E RIDGE AXIS.

.LONG TERM...(SUNDAY THROUGH THURSDAY)
ISSUED AT 426 AM MDT THU AUG 21 2014

00Z MEDIUM RANGE DETERMINISTIC MODELS CONTINUE TO PAINT A FAIRLY
SIMILAR PICTURE FOR SUNDAY AND MONDAY...BUT DEVIATE DRAMATICALLY
ON TUESDAY THROUGH THURSDAY. SATURDAYS FRONT WILL BE SOUTH OF THE
CWA FOR SUNDAY...WITH THE ASSOCIATED SHORTWAVE ENERGY LIFTING
NORTHEAST ACROSS THE DAKOTAS. LOOKS LIKE A RELATIVELY COOL AND
STABLE DAY SHAPING UP...WHICH WILL SUPPRESS MOST CONVECTIVE
CHANCES. THE GFS DOES PAINT SOME MOISTURE ALONG THE I80 CORRIDOR
FROM CHEYENNE TO SIDNEY AS THE WARM FRONT LIFTS BACK NORTH LATE
SUNDAY EVENING. SOUTHWEST FLOW WILL PERSIST ON MONDAY AS THE NEXT
SHORTWAVE DIVES SOUTHEAST INTO MONTANA/IDAHO. INCREASING MOISTURE
AND ASCENT WITH THE APPROACH OF THE UPSTREAM TROUGH WILL INCREASE
THUNDERSTORM CHANCES W-E MONDAY AND MONDAY NIGHT. IT AS AT THIS
TIME WHEN MODEL SOLUTIONS BEGIN TO DIVERGE. THE 00Z GFS AND
CANADIAN MAINTAIN A PROGRESSIVE PATTERN FOR THE TUE-THU TIMEFRAME.
MEANWHILE...THE STALWART ECMWF SHOWS THIS SHORTWAVE TROF BEGINNING
TO ELONGATE INTO NRN CALIFORNIA LATE MONDAY...EVENTUALLY CUTTING
OFF OVR THE GREAT BASIN MID-WEEK. THE DOWNSTREAM IMPACTS ARE
MANY...PENDING WHICH SOLUTION IS CORRECT. HAVE LARGELY DISCOUNTED
THE 00Z ECMWF GIVEN ITS DEVIATION RUN-TO-RUN AS WELL AS FROM OTHER
GLOBAL MODELS. OF COURSE...ANY ADDL SUPPORT BOTH RUN-TO-RUN OR
AMONGST OTHER GLOBAL MODELS IN FUTURE OUTPUT WOULD ADD CREDENCE TO
THIS OUTCOME. IN THE NON-ECMWF SOLUTION...ANOTHER FRONT WOULD
SLICE THRU THE CWA ON TUESDAY... USHERING THE COOLEST TEMPS OF THE
WEEK AND ANOTHER GOOD CHANCE FOR PRECIP. PRECIP WILL EXIT QUICKLY
TUE NT...WITH DRIER AND WARMER CONDITIONS EXPECTED FOR WED AND
THU.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 426 AM MDT THU AUG 21 2014

VFR CONDITIONS WILL PREVAIL THROUGH THE PERIOD...AS THE AREA
REMAINS IN BETWEEN SYSTEMS. TERMINALS CAN EXPECT JUST SOME PASSING
MID/HIGH-LEVEL CLOUDS FROM TIME TO TIME. OTHERWISE...WEST WINDS
WILL GUST TO 15-25 KNOTS AT SE WYOMING SITES 16-24Z.


&&

.FIRE WEATHER...
ISSUED AT 426 AM MDT THU AUG 21 2014

MINIMAL CONCERNS AS THE WINDS AND HUMIDITIES REMAIN BELOW
CRITICAL THRESHOLDS.

&&

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

$$

UPDATE...TJT
SHORT TERM...RUBIN
LONG TERM...HAHN
AVIATION...HAHN
FIRE WEATHER...RUBIN








000
FXUS65 KCYS 211029
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
429 AM MDT THU AUG 21 2014

.SHORT TERM...(TODAY THROUGH SATURDAY NIGHT)
ISSUED AT 426 AM MDT THU AUG 21 2014

FLOW ALOFT REMAINS SOUTHWEST. ISOLATED TO SCATTERED LATE DAY
SHOWERS AND THUNDERSTORMS ON TAP WEST OF A LARAMIE TO CHADRON LINE
WHERE MOISTURE AND INSTABILITY WILL COINCIDE ALONG WITH BEST UPPER
FORCING.

TONIGHT...COLD FRONT MOVES WEST TO EAST ACROSS THE COUNTIES WITH A
FEW SHOWERS POSSIBLE LATE NORTH OF A LUSK TO SIDNEY LINE.

FRIDAY...NEXT NEGATIVELY TILTED SHORTWAVE TROUGH ALOFT MOVES ACROSS
WESTERN COLORADO...WITH MID LEVEL SHORTWAVE TROUGH OVER NORTHERN
COLORADO COMBINED WITH ADEQUATE LOW AND MID LEVEL MOISTURE TO
PRODUCE SCATTERED LATE DAY SHOWERS AND THUNDERSTORMS...MOST
NUMEROUS EAST OF A CHEYENNE TO LUSK LINE.

FRIDAY NIGHT...SHORTWAVE TROUGH ALOFT ROTATES NORTHEAST ACROSS
EASTERN WYOMING AND WESTERN NEBRASKA...WITH AT LEAST SCATTERED
SHOWERS AND THUNDERSTORMS DEVELOPING...LIKELY MOST NUMEROUS ACROSS
WESTERN NEBRASKA.

SATURDAY...UNSETTLED PATTERN CONTINUES OVER OUR COUNTIES AS THE
DOMINANT UPPER TROUGH PREVAILS OVER MONTANA AND WYOMING...WITH THE
NEXT SHORTWAVE TROUGH ALOFT ROTATING ACROSS WESTERN WYOMING...
PRODUCING AT LEAST SCATTERED SHOWERS AND THUNDERSTORMS NEAR THE LOW
AND MID LEVEL THETA-E RIDGE AXIS.

.LONG TERM...(SUNDAY THROUGH THURSDAY)
ISSUED AT 426 AM MDT THU AUG 21 2014

00Z MEDIUM RANGE DETERMINISTIC MODELS CONTINUE TO PAINT A FAIRLY
SIMILAR PICTURE FOR SUNDAY AND MONDAY...BUT DEVIATE DRAMATICALLY
ON TUESDAY THROUGH THURSDAY. SATURDAYS FRONT WILL BE SOUTH OF THE
CWA FOR SUNDAY...WITH THE ASSOCIATED SHORTWAVE ENERGY LIFTING
NORTHEAST ACROSS THE DAKOTAS. LOOKS LIKE A RELATIVELY COOL AND
STABLE DAY SHAPING UP...WHICH WILL SUPPRESS MOST CONVECTIVE
CHANCES. THE GFS DOES PAINT SOME MOISTURE ALONG THE I80 CORRIDOR
FROM CHEYENNE TO SIDNEY AS THE WARM FRONT LIFTS BACK NORTH LATE
SUNDAY EVENING. SOUTHWEST FLOW WILL PERSIST ON MONDAY AS THE NEXT
SHORTWAVE DIVES SOUTHEAST INTO MONTANA/IDAHO. INCREASING MOISTURE
AND ASCENT WITH THE APPROACH OF THE UPSTREAM TROUGH WILL INCREASE
THUNDERSTORM CHANCES W-E MONDAY AND MONDAY NIGHT. IT AS AT THIS
TIME WHEN MODEL SOLUTIONS BEGIN TO DIVERGE. THE 00Z GFS AND
CANADIAN MAINTAIN A PROGRESSIVE PATTERN FOR THE TUE-THU TIMEFRAME.
MEANWHILE...THE STALWART ECMWF SHOWS THIS SHORTWAVE TROF BEGINNING
TO ELONGATE INTO NRN CALIFORNIA LATE MONDAY...EVENTUALLY CUTTING
OFF OVR THE GREAT BASIN MID-WEEK. THE DOWNSTREAM IMPACTS ARE
MANY...PENDING WHICH SOLUTION IS CORRECT. HAVE LARGELY DISCOUNTED
THE 00Z ECMWF GIVEN ITS DEVIATION RUN-TO-RUN AS WELL AS FROM OTHER
GLOBAL MODELS. OF COURSE...ANY ADDL SUPPORT BOTH RUN-TO-RUN OR
AMONGST OTHER GLOBAL MODELS IN FUTURE OUTPUT WOULD ADD CREDENCE TO
THIS OUTCOME. IN THE NON-ECMWF SOLUTION...ANOTHER FRONT WOULD
SLICE THRU THE CWA ON TUESDAY... USHERING THE COOLEST TEMPS OF THE
WEEK AND ANOTHER GOOD CHANCE FOR PRECIP. PRECIP WILL EXIT QUICKLY
TUE NT...WITH DRIER AND WARMER CONDITIONS EXPECTED FOR WED AND
THU.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 426 AM MDT THU AUG 21 2014

VFR CONDITIONS WILL PREVAIL THROUGH THE PERIOD...AS THE AREA
REMAINS IN BETWEEN SYSTEMS. TERMINALS CAN EXPECT JUST SOME PASSING
MID/HIGH-LEVEL CLOUDS FROM TIME TO TIME. OTHERWISE...WEST WINDS
WILL GUST TO 15-25 KNOTS AT SE WYOMING SITES 16-24Z.

&&

.FIRE WEATHER...
ISSUED AT 426 AM MDT THU AUG 21 2014

MINIMAL CONCERNS AS THE WINDS AND HUMIDITIES REMAIN BELOW
CRITICAL THRESHOLDS.

&&

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

&&

$$

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







000
FXUS65 KCYS 211029
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
429 AM MDT THU AUG 21 2014

.SHORT TERM...(TODAY THROUGH SATURDAY NIGHT)
ISSUED AT 426 AM MDT THU AUG 21 2014

FLOW ALOFT REMAINS SOUTHWEST. ISOLATED TO SCATTERED LATE DAY
SHOWERS AND THUNDERSTORMS ON TAP WEST OF A LARAMIE TO CHADRON LINE
WHERE MOISTURE AND INSTABILITY WILL COINCIDE ALONG WITH BEST UPPER
FORCING.

TONIGHT...COLD FRONT MOVES WEST TO EAST ACROSS THE COUNTIES WITH A
FEW SHOWERS POSSIBLE LATE NORTH OF A LUSK TO SIDNEY LINE.

FRIDAY...NEXT NEGATIVELY TILTED SHORTWAVE TROUGH ALOFT MOVES ACROSS
WESTERN COLORADO...WITH MID LEVEL SHORTWAVE TROUGH OVER NORTHERN
COLORADO COMBINED WITH ADEQUATE LOW AND MID LEVEL MOISTURE TO
PRODUCE SCATTERED LATE DAY SHOWERS AND THUNDERSTORMS...MOST
NUMEROUS EAST OF A CHEYENNE TO LUSK LINE.

FRIDAY NIGHT...SHORTWAVE TROUGH ALOFT ROTATES NORTHEAST ACROSS
EASTERN WYOMING AND WESTERN NEBRASKA...WITH AT LEAST SCATTERED
SHOWERS AND THUNDERSTORMS DEVELOPING...LIKELY MOST NUMEROUS ACROSS
WESTERN NEBRASKA.

SATURDAY...UNSETTLED PATTERN CONTINUES OVER OUR COUNTIES AS THE
DOMINANT UPPER TROUGH PREVAILS OVER MONTANA AND WYOMING...WITH THE
NEXT SHORTWAVE TROUGH ALOFT ROTATING ACROSS WESTERN WYOMING...
PRODUCING AT LEAST SCATTERED SHOWERS AND THUNDERSTORMS NEAR THE LOW
AND MID LEVEL THETA-E RIDGE AXIS.

.LONG TERM...(SUNDAY THROUGH THURSDAY)
ISSUED AT 426 AM MDT THU AUG 21 2014

00Z MEDIUM RANGE DETERMINISTIC MODELS CONTINUE TO PAINT A FAIRLY
SIMILAR PICTURE FOR SUNDAY AND MONDAY...BUT DEVIATE DRAMATICALLY
ON TUESDAY THROUGH THURSDAY. SATURDAYS FRONT WILL BE SOUTH OF THE
CWA FOR SUNDAY...WITH THE ASSOCIATED SHORTWAVE ENERGY LIFTING
NORTHEAST ACROSS THE DAKOTAS. LOOKS LIKE A RELATIVELY COOL AND
STABLE DAY SHAPING UP...WHICH WILL SUPPRESS MOST CONVECTIVE
CHANCES. THE GFS DOES PAINT SOME MOISTURE ALONG THE I80 CORRIDOR
FROM CHEYENNE TO SIDNEY AS THE WARM FRONT LIFTS BACK NORTH LATE
SUNDAY EVENING. SOUTHWEST FLOW WILL PERSIST ON MONDAY AS THE NEXT
SHORTWAVE DIVES SOUTHEAST INTO MONTANA/IDAHO. INCREASING MOISTURE
AND ASCENT WITH THE APPROACH OF THE UPSTREAM TROUGH WILL INCREASE
THUNDERSTORM CHANCES W-E MONDAY AND MONDAY NIGHT. IT AS AT THIS
TIME WHEN MODEL SOLUTIONS BEGIN TO DIVERGE. THE 00Z GFS AND
CANADIAN MAINTAIN A PROGRESSIVE PATTERN FOR THE TUE-THU TIMEFRAME.
MEANWHILE...THE STALWART ECMWF SHOWS THIS SHORTWAVE TROF BEGINNING
TO ELONGATE INTO NRN CALIFORNIA LATE MONDAY...EVENTUALLY CUTTING
OFF OVR THE GREAT BASIN MID-WEEK. THE DOWNSTREAM IMPACTS ARE
MANY...PENDING WHICH SOLUTION IS CORRECT. HAVE LARGELY DISCOUNTED
THE 00Z ECMWF GIVEN ITS DEVIATION RUN-TO-RUN AS WELL AS FROM OTHER
GLOBAL MODELS. OF COURSE...ANY ADDL SUPPORT BOTH RUN-TO-RUN OR
AMONGST OTHER GLOBAL MODELS IN FUTURE OUTPUT WOULD ADD CREDENCE TO
THIS OUTCOME. IN THE NON-ECMWF SOLUTION...ANOTHER FRONT WOULD
SLICE THRU THE CWA ON TUESDAY... USHERING THE COOLEST TEMPS OF THE
WEEK AND ANOTHER GOOD CHANCE FOR PRECIP. PRECIP WILL EXIT QUICKLY
TUE NT...WITH DRIER AND WARMER CONDITIONS EXPECTED FOR WED AND
THU.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 426 AM MDT THU AUG 21 2014

VFR CONDITIONS WILL PREVAIL THROUGH THE PERIOD...AS THE AREA
REMAINS IN BETWEEN SYSTEMS. TERMINALS CAN EXPECT JUST SOME PASSING
MID/HIGH-LEVEL CLOUDS FROM TIME TO TIME. OTHERWISE...WEST WINDS
WILL GUST TO 15-25 KNOTS AT SE WYOMING SITES 16-24Z.

&&

.FIRE WEATHER...
ISSUED AT 426 AM MDT THU AUG 21 2014

MINIMAL CONCERNS AS THE WINDS AND HUMIDITIES REMAIN BELOW
CRITICAL THRESHOLDS.

&&

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

&&

$$

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






000
FXUS65 KCYS 210507
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
1107 PM MDT WED AUG 20 2014

.UPDATE...
ISSUED AT 846 PM MDT WED AUG 20 2014

MIDLVL MOISTURE PLUME CONTINUES TO STREAM NORTHWARD ACROSS THE CWA
THIS EVE PER LATEST WATER VAPOR SAT. THIS HAS ALLOWED SHOWERS AND
TSTMS TO PERSIST ACROSS PARTS OF THE AREA WELL INTO THE EVE. KCYS
RADAR LOOP SHOWS TWO SEPARATE AREAS OF PCPN LIKELY IN ASSOCIATION
WITH TWO DISTINCT SHORTWAVES EMANATING FROM THE UPPER LOW SPINNING
OVER SOUTHERN CA. THESE AREAS ARE THE HIGHER TERRAIN OUT WEST OVER
CARBON AND ALBANY COUNTIES...AND AREAS EAST OF I25 ALONG THE I80
CORRIDOR ACROSS WESTERN NE. HRRR TRENDS HAVE HINTED AT CONVECTION
CONTINUING BEYOND 06Z OVER THE SOUTHERN PANHANDLE. ADDED POPS THRU
06Z WITH GOOD MOISTURE IN PLACE...BUT SHOWERS SHOULD BE DECREASING
IN COVERAGE BY THEN. THE REST OF THE INHERITED FCST IS IN GOOD
SHAPE THIS EVE.

&&

.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 330 PM MDT WED AUG 20 2014

CURRENT KCYS RADAR LOOP SHOWS SHOWERS AND FEW THUNDER SHOWERS
DEVELOPING OVER THE MOUNTAINS AND THE CHEYENNE RIDGE THIS
AFTERNOON...AND SLOWLY MOVING EASTWARD. ACTIVITY HAS BEEN WEAK
WITH ONLY A FEW ISOLATED LIGHTNING STRIKES. EXPECT THIS ACTIVITY
TO CONTINUE THROUGH INTO LATE THIS AFTERNOON AND EARLY THIS
EVENING WHILE DEVELOPING FURTHER EAST INTO THE HIGH PLAINS OF
SOUTHEAST WYOMING. EXPECT ANY THUNDERSTORMS TO QUICKLY DIMINISH
AROUND SUNSET.

THUNDERSTORM COVERAGE WILL LIKELY BE LOWER ON THURSDAY ACROSS MOST
OF THE FORECAST AREA AS WARMER AIR ALOFT MOVES INTO THE AREA AND
500MB HEIGHTS INCREASE THROUGH THE DAY. A COLD FRONT BOUNDARY WILL
BECOME MORE NOTICEABLE FURTHER NORTH ACROSS MONTANA AND NORTHERN
WYOMING AS IT SLOWLY DRIFTS SOUTHWARD THROUGH THE DAY.
THEREFORE...EXPECT THE BEST COVERAGE OF SHOWERS AND THUNDERSTORMS
TO BE ACROSS THE MOUNTAINS AND WELL NORTH OF I80. CAN NOT RULE OUT
A THUNDER SHOWER OR TWO ALONG THE I80 CORRIDOR DURING THE EVENING
HOURS. TEMPERATURES WILL REMAIN NEAR NORMAL AND GENERALLY IN THE
UPPER 70S WEST OF THE LARAMIE RANGE AND LOW 80S TO LOW 90S ACROSS
THE EASTERN PLAINS.

THIS PERSISTENT WEATHER PATTERN WILL BEGIN TO CHANGE ON FRIDAY AND
ESPECIALLY THIS WEEKEND. MODELS INDICATE A PRETTY STRONG COLD
FRONT FOR THIS TIME OF THE YEAR PUSHING SOUTHWARD INTO SOUTHEAST
WYOMING. THIS FRONT WILL STALL SOMETIME ON FRIDAY AND BE THE MAIN
FOCUS FOR SCATTERED TO NUMEROUS SHOWERS AND TSTORMS AS AN UPPER
LEVEL TROUGH FROM WESTERN CANADA MOVE SOUTH AND EVENTUALLY
EASTWARD INTO IDAHO. LOWERED MAX AND MIN TEMPERATURES FRIDAY AND
FRIDAY NIGHT AND INCREASED POP BETWEEN 25 TO 45 PERCENT ACROSS THE
HIGH PLAINS...AND NEAR 70 PERCENT OVER THE MOUNTAINS.

.LONG TERM...(SATURDAY THROUGH WEDNESDAY)
ISSUED AT 330 PM MDT WED AUG 20 2014

BOTH THE GFS AND ECMWF BRING A SHORTWAVE THROUGH THE AREA IN
SOUTHWEST WIND FLOW FRIDAY NIGHT INTO SATURDAY. ECMWF ROUGHLY 12
HOURS SLOWER THAN THE GFS...BUT BOTH ARE IN CLOSE AGREEMENT WITH
MOVEMENT OF FIRST DISTURBANCE...THEN MOVING THE MAIN TROUGH
THROUGH ON SATURDAY/SATURDAY NIGHT. JUST ABOUT EVERYONE SHOULD SEE
SHOWERS/THUNDERSTORMS DURING THE DAY SATURDAY WITH BEST CHANCES
FOR THE PANHANDLE SATURDAY NIGHT. MAIN SHORTWAVE THROUGH THE AREA
BY SUNDAY...WITH MAINLY ISOLATED SHOWERS OVER THE MOUNTAINS.

NEXT COLD FRONT LOOKS TO MOVE INTO THE AREA MONDAY AFTERNOON INTO
TUESDAY. ECMWF A LITTLE COLDER THAN GFS IN 700MB
TEMPERATURES...BUT NOT AS BAD AS A FEW DAYS AGO. PROBABLY NEED TO
GO COLDER WITH THIS SETUP. DISCREPANCY MUCH GREATER ON TUESDAY
WITH THE ECMWF FORECASTING 700MB TEMPERATURES OF +4 TO +6C AND GFS
SHOWING +10 TO +12C.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY EVENING)
ISSUED AT 1104 PM MDT WED AUG 20 2014

A FEW LINGERING SHOWERS AND THUNDERSTORMS AS OF 5Z WILL MOSTLY DIE
OFF IN THE NEXT FEW HOURS. OUTSIDE ANY SHOWER OR THUNDERSTORM
ACTIVITY...VFR WILL OCCUR THROUGH THE TAF PERIOD. WINDS WILL
GENERALLY REMAIN LIGHT THROUGH THURSDAY BUT SOME GUSTS TO 25 MPH
CAN BE EXPECTED THURSDAY AFTERNOON ALONG AND WEST OF THE LARAMIE
RANGE. A FEW THUNDERSTORMS WILL BE POSSIBLE THURSDAY AFTERNOON AND
EARLY EVENING.

&&

.FIRE WEATHER...
ISSUED AT 156 PM MDT WED AUG 20 2014

MINIMAL FIRE WEATHER CONCERNS INTO EARLY NEXT WEEK. SUBTROPICAL
MOISTURE WILL REMAIN OVER THE AREA THROUGH THE WEEKEND WITH
SHOWERS AND THUNDERSTORMS POSSIBLE EACH DAY ACROSS SOUTHEAST
WYOMING AND WESTERN NEBRASKA. THERE IS A GOOD CHANCE OF WETTING
RAINS BY FRIDAY AND THIS WEEKEND AS THUNDERSTORM COVERAGE WILL BE
HIGHER. TEMPERATURES WILL TREND COOLER BY LATE THIS WEEK AND INTO
THIS WEEKEND AS A STRONG COLD FRONT FOR THIS TIME OF THE YEAR
MOVES INTO THE REGION LATE ON SATURDAY.

&&

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

$$

UPDATE...HAMMER
SHORT TERM...TJT
LONG TERM...CLAYCOMB
AVIATION...SML
FIRE WEATHER...TJT







000
FXUS65 KCYS 210507
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
1107 PM MDT WED AUG 20 2014

.UPDATE...
ISSUED AT 846 PM MDT WED AUG 20 2014

MIDLVL MOISTURE PLUME CONTINUES TO STREAM NORTHWARD ACROSS THE CWA
THIS EVE PER LATEST WATER VAPOR SAT. THIS HAS ALLOWED SHOWERS AND
TSTMS TO PERSIST ACROSS PARTS OF THE AREA WELL INTO THE EVE. KCYS
RADAR LOOP SHOWS TWO SEPARATE AREAS OF PCPN LIKELY IN ASSOCIATION
WITH TWO DISTINCT SHORTWAVES EMANATING FROM THE UPPER LOW SPINNING
OVER SOUTHERN CA. THESE AREAS ARE THE HIGHER TERRAIN OUT WEST OVER
CARBON AND ALBANY COUNTIES...AND AREAS EAST OF I25 ALONG THE I80
CORRIDOR ACROSS WESTERN NE. HRRR TRENDS HAVE HINTED AT CONVECTION
CONTINUING BEYOND 06Z OVER THE SOUTHERN PANHANDLE. ADDED POPS THRU
06Z WITH GOOD MOISTURE IN PLACE...BUT SHOWERS SHOULD BE DECREASING
IN COVERAGE BY THEN. THE REST OF THE INHERITED FCST IS IN GOOD
SHAPE THIS EVE.

&&

.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 330 PM MDT WED AUG 20 2014

CURRENT KCYS RADAR LOOP SHOWS SHOWERS AND FEW THUNDER SHOWERS
DEVELOPING OVER THE MOUNTAINS AND THE CHEYENNE RIDGE THIS
AFTERNOON...AND SLOWLY MOVING EASTWARD. ACTIVITY HAS BEEN WEAK
WITH ONLY A FEW ISOLATED LIGHTNING STRIKES. EXPECT THIS ACTIVITY
TO CONTINUE THROUGH INTO LATE THIS AFTERNOON AND EARLY THIS
EVENING WHILE DEVELOPING FURTHER EAST INTO THE HIGH PLAINS OF
SOUTHEAST WYOMING. EXPECT ANY THUNDERSTORMS TO QUICKLY DIMINISH
AROUND SUNSET.

THUNDERSTORM COVERAGE WILL LIKELY BE LOWER ON THURSDAY ACROSS MOST
OF THE FORECAST AREA AS WARMER AIR ALOFT MOVES INTO THE AREA AND
500MB HEIGHTS INCREASE THROUGH THE DAY. A COLD FRONT BOUNDARY WILL
BECOME MORE NOTICEABLE FURTHER NORTH ACROSS MONTANA AND NORTHERN
WYOMING AS IT SLOWLY DRIFTS SOUTHWARD THROUGH THE DAY.
THEREFORE...EXPECT THE BEST COVERAGE OF SHOWERS AND THUNDERSTORMS
TO BE ACROSS THE MOUNTAINS AND WELL NORTH OF I80. CAN NOT RULE OUT
A THUNDER SHOWER OR TWO ALONG THE I80 CORRIDOR DURING THE EVENING
HOURS. TEMPERATURES WILL REMAIN NEAR NORMAL AND GENERALLY IN THE
UPPER 70S WEST OF THE LARAMIE RANGE AND LOW 80S TO LOW 90S ACROSS
THE EASTERN PLAINS.

THIS PERSISTENT WEATHER PATTERN WILL BEGIN TO CHANGE ON FRIDAY AND
ESPECIALLY THIS WEEKEND. MODELS INDICATE A PRETTY STRONG COLD
FRONT FOR THIS TIME OF THE YEAR PUSHING SOUTHWARD INTO SOUTHEAST
WYOMING. THIS FRONT WILL STALL SOMETIME ON FRIDAY AND BE THE MAIN
FOCUS FOR SCATTERED TO NUMEROUS SHOWERS AND TSTORMS AS AN UPPER
LEVEL TROUGH FROM WESTERN CANADA MOVE SOUTH AND EVENTUALLY
EASTWARD INTO IDAHO. LOWERED MAX AND MIN TEMPERATURES FRIDAY AND
FRIDAY NIGHT AND INCREASED POP BETWEEN 25 TO 45 PERCENT ACROSS THE
HIGH PLAINS...AND NEAR 70 PERCENT OVER THE MOUNTAINS.

.LONG TERM...(SATURDAY THROUGH WEDNESDAY)
ISSUED AT 330 PM MDT WED AUG 20 2014

BOTH THE GFS AND ECMWF BRING A SHORTWAVE THROUGH THE AREA IN
SOUTHWEST WIND FLOW FRIDAY NIGHT INTO SATURDAY. ECMWF ROUGHLY 12
HOURS SLOWER THAN THE GFS...BUT BOTH ARE IN CLOSE AGREEMENT WITH
MOVEMENT OF FIRST DISTURBANCE...THEN MOVING THE MAIN TROUGH
THROUGH ON SATURDAY/SATURDAY NIGHT. JUST ABOUT EVERYONE SHOULD SEE
SHOWERS/THUNDERSTORMS DURING THE DAY SATURDAY WITH BEST CHANCES
FOR THE PANHANDLE SATURDAY NIGHT. MAIN SHORTWAVE THROUGH THE AREA
BY SUNDAY...WITH MAINLY ISOLATED SHOWERS OVER THE MOUNTAINS.

NEXT COLD FRONT LOOKS TO MOVE INTO THE AREA MONDAY AFTERNOON INTO
TUESDAY. ECMWF A LITTLE COLDER THAN GFS IN 700MB
TEMPERATURES...BUT NOT AS BAD AS A FEW DAYS AGO. PROBABLY NEED TO
GO COLDER WITH THIS SETUP. DISCREPANCY MUCH GREATER ON TUESDAY
WITH THE ECMWF FORECASTING 700MB TEMPERATURES OF +4 TO +6C AND GFS
SHOWING +10 TO +12C.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY EVENING)
ISSUED AT 1104 PM MDT WED AUG 20 2014

A FEW LINGERING SHOWERS AND THUNDERSTORMS AS OF 5Z WILL MOSTLY DIE
OFF IN THE NEXT FEW HOURS. OUTSIDE ANY SHOWER OR THUNDERSTORM
ACTIVITY...VFR WILL OCCUR THROUGH THE TAF PERIOD. WINDS WILL
GENERALLY REMAIN LIGHT THROUGH THURSDAY BUT SOME GUSTS TO 25 MPH
CAN BE EXPECTED THURSDAY AFTERNOON ALONG AND WEST OF THE LARAMIE
RANGE. A FEW THUNDERSTORMS WILL BE POSSIBLE THURSDAY AFTERNOON AND
EARLY EVENING.

&&

.FIRE WEATHER...
ISSUED AT 156 PM MDT WED AUG 20 2014

MINIMAL FIRE WEATHER CONCERNS INTO EARLY NEXT WEEK. SUBTROPICAL
MOISTURE WILL REMAIN OVER THE AREA THROUGH THE WEEKEND WITH
SHOWERS AND THUNDERSTORMS POSSIBLE EACH DAY ACROSS SOUTHEAST
WYOMING AND WESTERN NEBRASKA. THERE IS A GOOD CHANCE OF WETTING
RAINS BY FRIDAY AND THIS WEEKEND AS THUNDERSTORM COVERAGE WILL BE
HIGHER. TEMPERATURES WILL TREND COOLER BY LATE THIS WEEK AND INTO
THIS WEEKEND AS A STRONG COLD FRONT FOR THIS TIME OF THE YEAR
MOVES INTO THE REGION LATE ON SATURDAY.

&&

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

$$

UPDATE...HAMMER
SHORT TERM...TJT
LONG TERM...CLAYCOMB
AVIATION...SML
FIRE WEATHER...TJT








000
FXUS65 KCYS 210258
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
858 PM MDT WED AUG 20 2014

.UPDATE...
ISSUED AT 846 PM MDT WED AUG 20 2014

MIDLVL MOISTURE PLUME CONTINUES TO STREAM NORTHWARD ACROSS THE CWA
THIS EVE PER LATEST WATER VAPOR SAT. THIS HAS ALLOWED SHOWERS AND
TSTMS TO PERSIST ACROSS PARTS OF THE AREA WELL INTO THE EVE. KCYS
RADAR LOOP SHOWS TWO SEPARATE AREAS OF PCPN LIKELY IN ASSOCIATION
WITH TWO DISTINCT SHORTWAVES EMANATING FROM THE UPPER LOW SPINNING
OVER SOUTHERN CA. THESE AREAS ARE THE HIGHER TERRAIN OUT WEST OVER
CARBON AND ALBANY COUNTIES...AND AREAS EAST OF I25 ALONG THE I80
CORRIDOR ACROSS WESTERN NE. HRRR TRENDS HAVE HINTED AT CONVECTION
CONTINUING BEYOND 06Z OVER THE SOUTHERN PANHANDLE. ADDED POPS THRU
06Z WITH GOOD MOISTURE IN PLACE...BUT SHOWERS SHOULD BE DECREASING
IN COVERAGE BY THEN. THE REST OF THE INHERITED FCST IS IN GOOD
SHAPE THIS EVE.

&&

.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 330 PM MDT WED AUG 20 2014

CURRENT KCYS RADAR LOOP SHOWS SHOWERS AND FEW THUNDER SHOWERS
DEVELOPING OVER THE MOUNTAINS AND THE CHEYENNE RIDGE THIS
AFTERNOON...AND SLOWLY MOVING EASTWARD. ACTIVITY HAS BEEN WEAK
WITH ONLY A FEW ISOLATED LIGHTNING STRIKES. EXPECT THIS ACTIVITY
TO CONTINUE THROUGH INTO LATE THIS AFTERNOON AND EARLY THIS
EVENING WHILE DEVELOPING FURTHER EAST INTO THE HIGH PLAINS OF
SOUTHEAST WYOMING. EXPECT ANY THUNDERSTORMS TO QUICKLY DIMINISH
AROUND SUNSET.

THUNDERSTORM COVERAGE WILL LIKELY BE LOWER ON THURSDAY ACROSS MOST
OF THE FORECAST AREA AS WARMER AIR ALOFT MOVES INTO THE AREA AND
500MB HEIGHTS INCREASE THROUGH THE DAY. A COLD FRONT BOUNDARY WILL
BECOME MORE NOTICEABLE FURTHER NORTH ACROSS MONTANA AND NORTHERN
WYOMING AS IT SLOWLY DRIFTS SOUTHWARD THROUGH THE DAY.
THEREFORE...EXPECT THE BEST COVERAGE OF SHOWERS AND THUNDERSTORMS
TO BE ACROSS THE MOUNTAINS AND WELL NORTH OF I80. CAN NOT RULE OUT
A THUNDER SHOWER OR TWO ALONG THE I80 CORRIDOR DURING THE EVENING
HOURS. TEMPERATURES WILL REMAIN NEAR NORMAL AND GENERALLY IN THE
UPPER 70S WEST OF THE LARAMIE RANGE AND LOW 80S TO LOW 90S ACROSS
THE EASTERN PLAINS.

THIS PERSISTENT WEATHER PATTERN WILL BEGIN TO CHANGE ON FRIDAY AND
ESPECIALLY THIS WEEKEND. MODELS INDICATE A PRETTY STRONG COLD
FRONT FOR THIS TIME OF THE YEAR PUSHING SOUTHWARD INTO SOUTHEAST
WYOMING. THIS FRONT WILL STALL SOMETIME ON FRIDAY AND BE THE MAIN
FOCUS FOR SCATTERED TO NUMEROUS SHOWERS AND TSTORMS AS AN UPPER
LEVEL TROUGH FROM WESTERN CANADA MOVE SOUTH AND EVENTUALLY
EASTWARD INTO IDAHO. LOWERED MAX AND MIN TEMPERATURES FRIDAY AND
FRIDAY NIGHT AND INCREASED POP BETWEEN 25 TO 45 PERCENT ACROSS THE
HIGH PLAINS...AND NEAR 70 PERCENT OVER THE MOUNTAINS.

.LONG TERM...(SATURDAY THROUGH WEDNESDAY)
ISSUED AT 330 PM MDT WED AUG 20 2014

BOTH THE GFS AND ECMWF BRING A SHORTWAVE THROUGH THE AREA IN
SOUTHWEST WIND FLOW FRIDAY NIGHT INTO SATURDAY. ECMWF ROUGHLY 12
HOURS SLOWER THAN THE GFS...BUT BOTH ARE IN CLOSE AGREEMENT WITH
MOVEMENT OF FIRST DISTURBANCE...THEN MOVING THE MAIN TROUGH
THROUGH ON SATURDAY/SATURDAY NIGHT. JUST ABOUT EVERYONE SHOULD SEE
SHOWERS/THUNDERSTORMS DURING THE DAY SATURDAY WITH BEST CHANCES
FOR THE PANHANDLE SATURDAY NIGHT. MAIN SHORTWAVE THROUGH THE AREA
BY SUNDAY...WITH MAINLY ISOLATED SHOWERS OVER THE MOUNTAINS.

NEXT COLD FRONT LOOKS TO MOVE INTO THE AREA MONDAY AFTERNOON INTO
TUESDAY. ECMWF A LITTLE COLDER THAN GFS IN 700MB
TEMPERATURES...BUT NOT AS BAD AS A FEW DAYS AGO. PROBABLY NEED TO
GO COLDER WITH THIS SETUP. DISCREPANCY MUCH GREATER ON TUESDAY
WITH THE ECMWF FORECASTING 700MB TEMPERATURES OF +4 TO +6C AND GFS
SHOWING +10 TO +12C.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY AFTERNOON)
ISSUED AT 539 PM MDT WED AUG 20 2014

ISOLATED SHOWERS AND THUNDERSTORMS WILL DIE OFF THIS
EVENING BY AROUND 04Z. GUSTY WINDS AND SMALL HAIL POSSIBLE WITH
THUNDERSTORMS. OUTSIDE OF THUNDERSTORM ACTIVITY THIS EVENING WINDS
WILL BE LIGHT ACROSS SOUTHEAST WY AND NEBRASKA PANHANDLE TONIGHT.
WINDS WILL GENERALLY REMAIN LIGHT THROUGH THURSDAY BUT SOME GUSTS
TO 25 MPH CAN BE EXPECTED THURSDAY AFTERNOON ALONG AND WEST OF THE
LARAMIE RANGE. A FEW THUNDERSTORMS WILL BE POSSIBLE THURSDAY
AFTERNOON AND EARLY EVENING.


&&

.FIRE WEATHER...
ISSUED AT 156 PM MDT WED AUG 20 2014

MINIMAL FIRE WEATHER CONCERNS INTO EARLY NEXT WEEK. SUBTROPICAL
MOISTURE WILL REMAIN OVER THE AREA THROUGH THE WEEKEND WITH
SHOWERS AND THUNDERSTORMS POSSIBLE EACH DAY ACROSS SOUTHEAST
WYOMING AND WESTERN NEBRASKA. THERE IS A GOOD CHANCE OF WETTING
RAINS BY FRIDAY AND THIS WEEKEND AS THUNDERSTORM COVERAGE WILL BE
HIGHER. TEMPERATURES WILL TREND COOLER BY LATE THIS WEEK AND INTO
THIS WEEKEND AS A STRONG COLD FRONT FOR THIS TIME OF THE YEAR
MOVES INTO THE REGION LATE ON SATURDAY.

&&

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

$$

UPDATE...HAMMER
SHORT TERM...TJT
LONG TERM...CLAYCOMB
AVIATION...SML
FIRE WEATHER...TJT








000
FXUS65 KCYS 210258
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
858 PM MDT WED AUG 20 2014

.UPDATE...
ISSUED AT 846 PM MDT WED AUG 20 2014

MIDLVL MOISTURE PLUME CONTINUES TO STREAM NORTHWARD ACROSS THE CWA
THIS EVE PER LATEST WATER VAPOR SAT. THIS HAS ALLOWED SHOWERS AND
TSTMS TO PERSIST ACROSS PARTS OF THE AREA WELL INTO THE EVE. KCYS
RADAR LOOP SHOWS TWO SEPARATE AREAS OF PCPN LIKELY IN ASSOCIATION
WITH TWO DISTINCT SHORTWAVES EMANATING FROM THE UPPER LOW SPINNING
OVER SOUTHERN CA. THESE AREAS ARE THE HIGHER TERRAIN OUT WEST OVER
CARBON AND ALBANY COUNTIES...AND AREAS EAST OF I25 ALONG THE I80
CORRIDOR ACROSS WESTERN NE. HRRR TRENDS HAVE HINTED AT CONVECTION
CONTINUING BEYOND 06Z OVER THE SOUTHERN PANHANDLE. ADDED POPS THRU
06Z WITH GOOD MOISTURE IN PLACE...BUT SHOWERS SHOULD BE DECREASING
IN COVERAGE BY THEN. THE REST OF THE INHERITED FCST IS IN GOOD
SHAPE THIS EVE.

&&

.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 330 PM MDT WED AUG 20 2014

CURRENT KCYS RADAR LOOP SHOWS SHOWERS AND FEW THUNDER SHOWERS
DEVELOPING OVER THE MOUNTAINS AND THE CHEYENNE RIDGE THIS
AFTERNOON...AND SLOWLY MOVING EASTWARD. ACTIVITY HAS BEEN WEAK
WITH ONLY A FEW ISOLATED LIGHTNING STRIKES. EXPECT THIS ACTIVITY
TO CONTINUE THROUGH INTO LATE THIS AFTERNOON AND EARLY THIS
EVENING WHILE DEVELOPING FURTHER EAST INTO THE HIGH PLAINS OF
SOUTHEAST WYOMING. EXPECT ANY THUNDERSTORMS TO QUICKLY DIMINISH
AROUND SUNSET.

THUNDERSTORM COVERAGE WILL LIKELY BE LOWER ON THURSDAY ACROSS MOST
OF THE FORECAST AREA AS WARMER AIR ALOFT MOVES INTO THE AREA AND
500MB HEIGHTS INCREASE THROUGH THE DAY. A COLD FRONT BOUNDARY WILL
BECOME MORE NOTICEABLE FURTHER NORTH ACROSS MONTANA AND NORTHERN
WYOMING AS IT SLOWLY DRIFTS SOUTHWARD THROUGH THE DAY.
THEREFORE...EXPECT THE BEST COVERAGE OF SHOWERS AND THUNDERSTORMS
TO BE ACROSS THE MOUNTAINS AND WELL NORTH OF I80. CAN NOT RULE OUT
A THUNDER SHOWER OR TWO ALONG THE I80 CORRIDOR DURING THE EVENING
HOURS. TEMPERATURES WILL REMAIN NEAR NORMAL AND GENERALLY IN THE
UPPER 70S WEST OF THE LARAMIE RANGE AND LOW 80S TO LOW 90S ACROSS
THE EASTERN PLAINS.

THIS PERSISTENT WEATHER PATTERN WILL BEGIN TO CHANGE ON FRIDAY AND
ESPECIALLY THIS WEEKEND. MODELS INDICATE A PRETTY STRONG COLD
FRONT FOR THIS TIME OF THE YEAR PUSHING SOUTHWARD INTO SOUTHEAST
WYOMING. THIS FRONT WILL STALL SOMETIME ON FRIDAY AND BE THE MAIN
FOCUS FOR SCATTERED TO NUMEROUS SHOWERS AND TSTORMS AS AN UPPER
LEVEL TROUGH FROM WESTERN CANADA MOVE SOUTH AND EVENTUALLY
EASTWARD INTO IDAHO. LOWERED MAX AND MIN TEMPERATURES FRIDAY AND
FRIDAY NIGHT AND INCREASED POP BETWEEN 25 TO 45 PERCENT ACROSS THE
HIGH PLAINS...AND NEAR 70 PERCENT OVER THE MOUNTAINS.

.LONG TERM...(SATURDAY THROUGH WEDNESDAY)
ISSUED AT 330 PM MDT WED AUG 20 2014

BOTH THE GFS AND ECMWF BRING A SHORTWAVE THROUGH THE AREA IN
SOUTHWEST WIND FLOW FRIDAY NIGHT INTO SATURDAY. ECMWF ROUGHLY 12
HOURS SLOWER THAN THE GFS...BUT BOTH ARE IN CLOSE AGREEMENT WITH
MOVEMENT OF FIRST DISTURBANCE...THEN MOVING THE MAIN TROUGH
THROUGH ON SATURDAY/SATURDAY NIGHT. JUST ABOUT EVERYONE SHOULD SEE
SHOWERS/THUNDERSTORMS DURING THE DAY SATURDAY WITH BEST CHANCES
FOR THE PANHANDLE SATURDAY NIGHT. MAIN SHORTWAVE THROUGH THE AREA
BY SUNDAY...WITH MAINLY ISOLATED SHOWERS OVER THE MOUNTAINS.

NEXT COLD FRONT LOOKS TO MOVE INTO THE AREA MONDAY AFTERNOON INTO
TUESDAY. ECMWF A LITTLE COLDER THAN GFS IN 700MB
TEMPERATURES...BUT NOT AS BAD AS A FEW DAYS AGO. PROBABLY NEED TO
GO COLDER WITH THIS SETUP. DISCREPANCY MUCH GREATER ON TUESDAY
WITH THE ECMWF FORECASTING 700MB TEMPERATURES OF +4 TO +6C AND GFS
SHOWING +10 TO +12C.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY AFTERNOON)
ISSUED AT 539 PM MDT WED AUG 20 2014

ISOLATED SHOWERS AND THUNDERSTORMS WILL DIE OFF THIS
EVENING BY AROUND 04Z. GUSTY WINDS AND SMALL HAIL POSSIBLE WITH
THUNDERSTORMS. OUTSIDE OF THUNDERSTORM ACTIVITY THIS EVENING WINDS
WILL BE LIGHT ACROSS SOUTHEAST WY AND NEBRASKA PANHANDLE TONIGHT.
WINDS WILL GENERALLY REMAIN LIGHT THROUGH THURSDAY BUT SOME GUSTS
TO 25 MPH CAN BE EXPECTED THURSDAY AFTERNOON ALONG AND WEST OF THE
LARAMIE RANGE. A FEW THUNDERSTORMS WILL BE POSSIBLE THURSDAY
AFTERNOON AND EARLY EVENING.


&&

.FIRE WEATHER...
ISSUED AT 156 PM MDT WED AUG 20 2014

MINIMAL FIRE WEATHER CONCERNS INTO EARLY NEXT WEEK. SUBTROPICAL
MOISTURE WILL REMAIN OVER THE AREA THROUGH THE WEEKEND WITH
SHOWERS AND THUNDERSTORMS POSSIBLE EACH DAY ACROSS SOUTHEAST
WYOMING AND WESTERN NEBRASKA. THERE IS A GOOD CHANCE OF WETTING
RAINS BY FRIDAY AND THIS WEEKEND AS THUNDERSTORM COVERAGE WILL BE
HIGHER. TEMPERATURES WILL TREND COOLER BY LATE THIS WEEK AND INTO
THIS WEEKEND AS A STRONG COLD FRONT FOR THIS TIME OF THE YEAR
MOVES INTO THE REGION LATE ON SATURDAY.

&&

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

$$

UPDATE...HAMMER
SHORT TERM...TJT
LONG TERM...CLAYCOMB
AVIATION...SML
FIRE WEATHER...TJT







000
FXUS65 KCYS 202345
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
545 PM MDT WED AUG 20 2014

.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 330 PM MDT WED AUG 20 2014

CURRENT KCYS RADAR LOOP SHOWS SHOWERS AND FEW THUNDER SHOWERS
DEVELOPING OVER THE MOUNTAINS AND THE CHEYENNE RIDGE THIS
AFTERNOON...AND SLOWLY MOVING EASTWARD. ACTIVITY HAS BEEN WEAK
WITH ONLY A FEW ISOLATED LIGHTNING STRIKES. EXPECT THIS ACTIVITY
TO CONTINUE THROUGH INTO LATE THIS AFTERNOON AND EARLY THIS
EVENING WHILE DEVELOPING FURTHER EAST INTO THE HIGH PLAINS OF
SOUTHEAST WYOMING. EXPECT ANY THUNDERSTORMS TO QUICKLY DIMINISH
AROUND SUNSET.

THUNDERSTORM COVERAGE WILL LIKELY BE LOWER ON THURSDAY ACROSS MOST
OF THE FORECAST AREA AS WARMER AIR ALOFT MOVES INTO THE AREA AND
500MB HEIGHTS INCREASE THROUGH THE DAY. A COLD FRONT BOUNDARY WILL
BECOME MORE NOTICEABLE FURTHER NORTH ACROSS MONTANA AND NORTHERN
WYOMING AS IT SLOWLY DRIFTS SOUTHWARD THROUGH THE DAY.
THEREFORE...EXPECT THE BEST COVERAGE OF SHOWERS AND THUNDERSTORMS
TO BE ACROSS THE MOUNTAINS AND WELL NORTH OF I80. CAN NOT RULE OUT
A THUNDER SHOWER OR TWO ALONG THE I80 CORRIDOR DURING THE EVENING
HOURS. TEMPERATURES WILL REMAIN NEAR NORMAL AND GENERALLY IN THE
UPPER 70S WEST OF THE LARAMIE RANGE AND LOW 80S TO LOW 90S ACROSS
THE EASTERN PLAINS.

THIS PERSISTENT WEATHER PATTERN WILL BEGIN TO CHANGE ON FRIDAY AND
ESPECIALLY THIS WEEKEND. MODELS INDICATE A PRETTY STRONG COLD
FRONT FOR THIS TIME OF THE YEAR PUSHING SOUTHWARD INTO SOUTHEAST
WYOMING. THIS FRONT WILL STALL SOMETIME ON FRIDAY AND BE THE MAIN
FOCUS FOR SCATTERED TO NUMEROUS SHOWERS AND TSTORMS AS AN UPPER
LEVEL TROUGH FROM WESTERN CANADA MOVE SOUTH AND EVENTUALLY
EASTWARD INTO IDAHO. LOWERED MAX AND MIN TEMPERATURES FRIDAY AND
FRIDAY NIGHT AND INCREASED POP BETWEEN 25 TO 45 PERCENT ACROSS THE
HIGH PLAINS...AND NEAR 70 PERCENT OVER THE MOUNTAINS.

.LONG TERM...(SATURDAY THROUGH WEDNESDAY)
ISSUED AT 330 PM MDT WED AUG 20 2014

BOTH THE GFS AND ECMWF BRING A SHORTWAVE THROUGH THE AREA IN
SOUTHWEST WIND FLOW FRIDAY NIGHT INTO SATURDAY. ECMWF ROUGHLY 12
HOURS SLOWER THAN THE GFS...BUT BOTH ARE IN CLOSE AGREEMENT WITH
MOVEMENT OF FIRST DISTURBANCE...THEN MOVING THE MAIN TROUGH
THROUGH ON SATURDAY/SATURDAY NIGHT. JUST ABOUT EVERYONE SHOULD SEE
SHOWERS/THUNDERSTORMS DURING THE DAY SATURDAY WITH BEST CHANCES
FOR THE PANHANDLE SATURDAY NIGHT. MAIN SHORTWAVE THROUGH THE AREA
BY SUNDAY...WITH MAINLY ISOLATED SHOWERS OVER THE MOUNTAINS.

NEXT COLD FRONT LOOKS TO MOVE INTO THE AREA MONDAY AFTERNOON INTO
TUESDAY. ECMWF A LITTLE COLDER THAN GFS IN 700MB
TEMPERATURES...BUT NOT AS BAD AS A FEW DAYS AGO. PROBABLY NEED TO
GO COLDER WITH THIS SETUP. DISCREPANCY MUCH GREATER ON TUESDAY
WITH THE ECMWF FORECASTING 700MB TEMPERATURES OF +4 TO +6C AND GFS
SHOWING +10 TO +12C.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY AFTERNOON)
ISSUED AT 539 PM MDT WED AUG 20 2014

ISOLATED SHOWERS AND THUNDERSTORMS WILL DIE OFF THIS
EVENING BY AROUND 04Z. GUSTY WINDS AND SMALL HAIL POSSIBLE WITH
THUNDERSTORMS. OUTSIDE OF THUNDERSTORM ACTIVITY THIS EVENING WINDS
WILL BE LIGHT ACROSS SOUTHEAST WY AND NEBRASKA PANHANDLE TONIGHT.
WINDS WILL GENERALLY REMAIN LIGHT THROUGH THURSDAY BUT SOME GUSTS
TO 25 MPH CAN BE EXPECTED THURSDAY AFTERNOON ALONG AND WEST OF THE
LARAMIE RANGE. A FEW THUNDERSTORMS WILL BE POSSIBLE THURSDAY
AFTERNOON AND EARLY EVENING.



&&

.FIRE WEATHER...
ISSUED AT 156 PM MDT WED AUG 20 2014

MINIMAL FIRE WEATHER CONCERNS INTO EARLY NEXT WEEK. SUBTROPICAL
MOISTURE WILL REMAIN OVER THE AREA THROUGH THE WEEKEND WITH
SHOWERS AND THUNDERSTORMS POSSIBLE EACH DAY ACROSS SOUTHEAST
WYOMING AND WESTERN NEBRASKA. THERE IS A GOOD CHANCE OF WETTING
RAINS BY FRIDAY AND THIS WEEKEND AS THUNDERSTORM COVERAGE WILL BE
HIGHER. TEMPERATURES WILL TREND COOLER BY LATE THIS WEEK AND INTO
THIS WEEKEND AS A STRONG COLD FRONT FOR THIS TIME OF THE YEAR
MOVES INTO THE REGION LATE ON SATURDAY.

&&

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

$$

SHORT TERM...TJT
LONG TERM...CLAYCOMB
AVIATION...SML
FIRE WEATHER...TJT







000
FXUS65 KCYS 202345
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
545 PM MDT WED AUG 20 2014

.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 330 PM MDT WED AUG 20 2014

CURRENT KCYS RADAR LOOP SHOWS SHOWERS AND FEW THUNDER SHOWERS
DEVELOPING OVER THE MOUNTAINS AND THE CHEYENNE RIDGE THIS
AFTERNOON...AND SLOWLY MOVING EASTWARD. ACTIVITY HAS BEEN WEAK
WITH ONLY A FEW ISOLATED LIGHTNING STRIKES. EXPECT THIS ACTIVITY
TO CONTINUE THROUGH INTO LATE THIS AFTERNOON AND EARLY THIS
EVENING WHILE DEVELOPING FURTHER EAST INTO THE HIGH PLAINS OF
SOUTHEAST WYOMING. EXPECT ANY THUNDERSTORMS TO QUICKLY DIMINISH
AROUND SUNSET.

THUNDERSTORM COVERAGE WILL LIKELY BE LOWER ON THURSDAY ACROSS MOST
OF THE FORECAST AREA AS WARMER AIR ALOFT MOVES INTO THE AREA AND
500MB HEIGHTS INCREASE THROUGH THE DAY. A COLD FRONT BOUNDARY WILL
BECOME MORE NOTICEABLE FURTHER NORTH ACROSS MONTANA AND NORTHERN
WYOMING AS IT SLOWLY DRIFTS SOUTHWARD THROUGH THE DAY.
THEREFORE...EXPECT THE BEST COVERAGE OF SHOWERS AND THUNDERSTORMS
TO BE ACROSS THE MOUNTAINS AND WELL NORTH OF I80. CAN NOT RULE OUT
A THUNDER SHOWER OR TWO ALONG THE I80 CORRIDOR DURING THE EVENING
HOURS. TEMPERATURES WILL REMAIN NEAR NORMAL AND GENERALLY IN THE
UPPER 70S WEST OF THE LARAMIE RANGE AND LOW 80S TO LOW 90S ACROSS
THE EASTERN PLAINS.

THIS PERSISTENT WEATHER PATTERN WILL BEGIN TO CHANGE ON FRIDAY AND
ESPECIALLY THIS WEEKEND. MODELS INDICATE A PRETTY STRONG COLD
FRONT FOR THIS TIME OF THE YEAR PUSHING SOUTHWARD INTO SOUTHEAST
WYOMING. THIS FRONT WILL STALL SOMETIME ON FRIDAY AND BE THE MAIN
FOCUS FOR SCATTERED TO NUMEROUS SHOWERS AND TSTORMS AS AN UPPER
LEVEL TROUGH FROM WESTERN CANADA MOVE SOUTH AND EVENTUALLY
EASTWARD INTO IDAHO. LOWERED MAX AND MIN TEMPERATURES FRIDAY AND
FRIDAY NIGHT AND INCREASED POP BETWEEN 25 TO 45 PERCENT ACROSS THE
HIGH PLAINS...AND NEAR 70 PERCENT OVER THE MOUNTAINS.

.LONG TERM...(SATURDAY THROUGH WEDNESDAY)
ISSUED AT 330 PM MDT WED AUG 20 2014

BOTH THE GFS AND ECMWF BRING A SHORTWAVE THROUGH THE AREA IN
SOUTHWEST WIND FLOW FRIDAY NIGHT INTO SATURDAY. ECMWF ROUGHLY 12
HOURS SLOWER THAN THE GFS...BUT BOTH ARE IN CLOSE AGREEMENT WITH
MOVEMENT OF FIRST DISTURBANCE...THEN MOVING THE MAIN TROUGH
THROUGH ON SATURDAY/SATURDAY NIGHT. JUST ABOUT EVERYONE SHOULD SEE
SHOWERS/THUNDERSTORMS DURING THE DAY SATURDAY WITH BEST CHANCES
FOR THE PANHANDLE SATURDAY NIGHT. MAIN SHORTWAVE THROUGH THE AREA
BY SUNDAY...WITH MAINLY ISOLATED SHOWERS OVER THE MOUNTAINS.

NEXT COLD FRONT LOOKS TO MOVE INTO THE AREA MONDAY AFTERNOON INTO
TUESDAY. ECMWF A LITTLE COLDER THAN GFS IN 700MB
TEMPERATURES...BUT NOT AS BAD AS A FEW DAYS AGO. PROBABLY NEED TO
GO COLDER WITH THIS SETUP. DISCREPANCY MUCH GREATER ON TUESDAY
WITH THE ECMWF FORECASTING 700MB TEMPERATURES OF +4 TO +6C AND GFS
SHOWING +10 TO +12C.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY AFTERNOON)
ISSUED AT 539 PM MDT WED AUG 20 2014

ISOLATED SHOWERS AND THUNDERSTORMS WILL DIE OFF THIS
EVENING BY AROUND 04Z. GUSTY WINDS AND SMALL HAIL POSSIBLE WITH
THUNDERSTORMS. OUTSIDE OF THUNDERSTORM ACTIVITY THIS EVENING WINDS
WILL BE LIGHT ACROSS SOUTHEAST WY AND NEBRASKA PANHANDLE TONIGHT.
WINDS WILL GENERALLY REMAIN LIGHT THROUGH THURSDAY BUT SOME GUSTS
TO 25 MPH CAN BE EXPECTED THURSDAY AFTERNOON ALONG AND WEST OF THE
LARAMIE RANGE. A FEW THUNDERSTORMS WILL BE POSSIBLE THURSDAY
AFTERNOON AND EARLY EVENING.



&&

.FIRE WEATHER...
ISSUED AT 156 PM MDT WED AUG 20 2014

MINIMAL FIRE WEATHER CONCERNS INTO EARLY NEXT WEEK. SUBTROPICAL
MOISTURE WILL REMAIN OVER THE AREA THROUGH THE WEEKEND WITH
SHOWERS AND THUNDERSTORMS POSSIBLE EACH DAY ACROSS SOUTHEAST
WYOMING AND WESTERN NEBRASKA. THERE IS A GOOD CHANCE OF WETTING
RAINS BY FRIDAY AND THIS WEEKEND AS THUNDERSTORM COVERAGE WILL BE
HIGHER. TEMPERATURES WILL TREND COOLER BY LATE THIS WEEK AND INTO
THIS WEEKEND AS A STRONG COLD FRONT FOR THIS TIME OF THE YEAR
MOVES INTO THE REGION LATE ON SATURDAY.

&&

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

$$

SHORT TERM...TJT
LONG TERM...CLAYCOMB
AVIATION...SML
FIRE WEATHER...TJT








000
FXUS65 KCYS 202130
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
330 PM MDT WED AUG 20 2014

.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 330 PM MDT WED AUG 20 2014

CURRENT KCYS RADAR LOOP SHOWS SHOWERS AND FEW THUNDER SHOWERS
DEVELOPING OVER THE MOUNTAINS AND THE CHEYENNE RIDGE THIS
AFTERNOON...AND SLOWLY MOVING EASTWARD. ACTIVITY HAS BEEN WEAK
WITH ONLY A FEW ISOLATED LIGHTNING STRIKES. EXPECT THIS ACTIVITY
TO CONTINUE THROUGH INTO LATE THIS AFTERNOON AND EARLY THIS
EVENING WHILE DEVELOPING FURTHER EAST INTO THE HIGH PLAINS OF
SOUTHEAST WYOMING. EXPECT ANY THUNDERSTORMS TO QUICKLY DIMINISH
AROUND SUNSET.

THUNDERSTORM COVERAGE WILL LIKELY BE LOWER ON THURSDAY ACROSS MOST
OF THE FORECAST AREA AS WARMER AIR ALOFT MOVES INTO THE AREA AND
500MB HEIGHTS INCREASE THROUGH THE DAY. A COLD FRONT BOUNDARY WILL
BECOME MORE NOTICEABLE FURTHER NORTH ACROSS MONTANA AND NORTHERN
WYOMING AS IT SLOWLY DRIFTS SOUTHWARD THROUGH THE DAY.
THEREFORE...EXPECT THE BEST COVERAGE OF SHOWERS AND THUNDERSTORMS
TO BE ACROSS THE MOUNTAINS AND WELL NORTH OF I80. CAN NOT RULE OUT
A THUNDER SHOWER OR TWO ALONG THE I80 CORRIDOR DURING THE EVENING
HOURS. TEMPERATURES WILL REMAIN NEAR NORMAL AND GENERALLY IN THE
UPPER 70S WEST OF THE LARAMIE RANGE AND LOW 80S TO LOW 90S ACROSS
THE EASTERN PLAINS.

THIS PERSISTENT WEATHER PATTERN WILL BEGIN TO CHANGE ON FRIDAY AND
ESPECIALLY THIS WEEKEND. MODELS INDICATE A PRETTY STRONG COLD
FRONT FOR THIS TIME OF THE YEAR PUSHING SOUTHWARD INTO SOUTHEAST
WYOMING. THIS FRONT WILL STALL SOMETIME ON FRIDAY AND BE THE MAIN
FOCUS FOR SCATTERED TO NUMEROUS SHOWERS AND TSTORMS AS AN UPPER
LEVEL TROUGH FROM WESTERN CANADA MOVE SOUTH AND EVENTUALLY
EASTWARD INTO IDAHO. LOWERED MAX AND MIN TEMPERATURES FRIDAY AND
FRIDAY NIGHT AND INCREASED POP BETWEEN 25 TO 45 PERCENT ACROSS THE
HIGH PLAINS...AND NEAR 70 PERCENT OVER THE MOUNTAINS.



.LONG TERM...(SATURDAY THROUGH WEDNESDAY)
ISSUED AT 330 PM MDT WED AUG 20 2014

BOTH THE GFS AND ECMWF BRING A SHORTWAVE THROUGH THE AREA IN
SOUTHWEST WIND FLOW FRIDAY NIGHT INTO SATURDAY. ECMWF ROUGHLY 12
HOURS SLOWER THAN THE GFS...BUT BOTH ARE IN CLOSE AGREEMENT WITH
MOVEMENT OF FIRST DISTURBANCE...THEN MOVING THE MAIN TROUGH
THROUGH ON SATURDAY/SATURDAY NIGHT. JUST ABOUT EVERYONE SHOULD SEE
SHOWERS/THUNDERSTORMS DURING THE DAY SATURDAY WITH BEST CHANCES
FOR THE PANHANDLE SATURDAY NIGHT. MAIN SHORTWAVE THROUGH THE AREA
BY SUNDAY...WITH MAINLY ISOLATED SHOWERS OVER THE MOUNTAINS.

NEXT COLD FRONT LOOKS TO MOVE INTO THE AREA MONDAY AFTERNOON INTO
TUESDAY. ECMWF A LITTLE COLDER THAN GFS IN 700MB
TEMPERATURES...BUT NOT AS BAD AS A FEW DAYS AGO. PROBABLY NEED TO
GO COLDER WITH THIS SETUP. DISCREPANCY MUCH GREATER ON TUESDAY
WITH THE ECMWF FORECASTING 700MB TEMPERATURES OF +4 TO +6C AND GFS
SHOWING +10 TO +12C.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY MORNING)
ISSUED AT 330 PM MDT WED AUG 20 2014

FOLLOWED LATEST HRRR GUIDANCE FOR TIMING ON SHOWERS AND
THUNDERSTORMS FOR SOUTHEAST WYOMING AND NEBRASKA PANHANDLE
AIRPORTS THIS AFTERNOON. HRRR HAS BEEN DOING WELL ON THE EARLY
MORNING CONVECTION...SO SEE NO REASON TO DEVIATE.

&&

.FIRE WEATHER...
ISSUED AT 156 PM MDT WED AUG 20 2014

MINIMAL FIRE WEATHER CONCERNS INTO EARLY NEXT WEEK. SUBTROPICAL
MOISTURE WILL REMAIN OVER THE AREA THROUGH THE WEEKEND WITH
SHOWERS AND THUNDERSTORMS POSSIBLE EACH DAY ACROSS SOUTHEAST
WYOMING AND WESTERN NEBRASKA. THERE IS A GOOD CHANCE OF WETTING
RAINS BY FRIDAY AND THIS WEEKEND AS THUNDERSTORM COVERAGE WILL BE
HIGHER. TEMPERATURES WILL TREND COOLER BY LATE THIS WEEK AND INTO
THIS WEEKEND AS A STRONG COLD FRONT FOR THIS TIME OF THE YEAR
MOVES INTO THE REGION LATE ON SATURDAY.



&&

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

$$

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












000
FXUS65 KCYS 202130
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
330 PM MDT WED AUG 20 2014

.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 330 PM MDT WED AUG 20 2014

CURRENT KCYS RADAR LOOP SHOWS SHOWERS AND FEW THUNDER SHOWERS
DEVELOPING OVER THE MOUNTAINS AND THE CHEYENNE RIDGE THIS
AFTERNOON...AND SLOWLY MOVING EASTWARD. ACTIVITY HAS BEEN WEAK
WITH ONLY A FEW ISOLATED LIGHTNING STRIKES. EXPECT THIS ACTIVITY
TO CONTINUE THROUGH INTO LATE THIS AFTERNOON AND EARLY THIS
EVENING WHILE DEVELOPING FURTHER EAST INTO THE HIGH PLAINS OF
SOUTHEAST WYOMING. EXPECT ANY THUNDERSTORMS TO QUICKLY DIMINISH
AROUND SUNSET.

THUNDERSTORM COVERAGE WILL LIKELY BE LOWER ON THURSDAY ACROSS MOST
OF THE FORECAST AREA AS WARMER AIR ALOFT MOVES INTO THE AREA AND
500MB HEIGHTS INCREASE THROUGH THE DAY. A COLD FRONT BOUNDARY WILL
BECOME MORE NOTICEABLE FURTHER NORTH ACROSS MONTANA AND NORTHERN
WYOMING AS IT SLOWLY DRIFTS SOUTHWARD THROUGH THE DAY.
THEREFORE...EXPECT THE BEST COVERAGE OF SHOWERS AND THUNDERSTORMS
TO BE ACROSS THE MOUNTAINS AND WELL NORTH OF I80. CAN NOT RULE OUT
A THUNDER SHOWER OR TWO ALONG THE I80 CORRIDOR DURING THE EVENING
HOURS. TEMPERATURES WILL REMAIN NEAR NORMAL AND GENERALLY IN THE
UPPER 70S WEST OF THE LARAMIE RANGE AND LOW 80S TO LOW 90S ACROSS
THE EASTERN PLAINS.

THIS PERSISTENT WEATHER PATTERN WILL BEGIN TO CHANGE ON FRIDAY AND
ESPECIALLY THIS WEEKEND. MODELS INDICATE A PRETTY STRONG COLD
FRONT FOR THIS TIME OF THE YEAR PUSHING SOUTHWARD INTO SOUTHEAST
WYOMING. THIS FRONT WILL STALL SOMETIME ON FRIDAY AND BE THE MAIN
FOCUS FOR SCATTERED TO NUMEROUS SHOWERS AND TSTORMS AS AN UPPER
LEVEL TROUGH FROM WESTERN CANADA MOVE SOUTH AND EVENTUALLY
EASTWARD INTO IDAHO. LOWERED MAX AND MIN TEMPERATURES FRIDAY AND
FRIDAY NIGHT AND INCREASED POP BETWEEN 25 TO 45 PERCENT ACROSS THE
HIGH PLAINS...AND NEAR 70 PERCENT OVER THE MOUNTAINS.



.LONG TERM...(SATURDAY THROUGH WEDNESDAY)
ISSUED AT 330 PM MDT WED AUG 20 2014

BOTH THE GFS AND ECMWF BRING A SHORTWAVE THROUGH THE AREA IN
SOUTHWEST WIND FLOW FRIDAY NIGHT INTO SATURDAY. ECMWF ROUGHLY 12
HOURS SLOWER THAN THE GFS...BUT BOTH ARE IN CLOSE AGREEMENT WITH
MOVEMENT OF FIRST DISTURBANCE...THEN MOVING THE MAIN TROUGH
THROUGH ON SATURDAY/SATURDAY NIGHT. JUST ABOUT EVERYONE SHOULD SEE
SHOWERS/THUNDERSTORMS DURING THE DAY SATURDAY WITH BEST CHANCES
FOR THE PANHANDLE SATURDAY NIGHT. MAIN SHORTWAVE THROUGH THE AREA
BY SUNDAY...WITH MAINLY ISOLATED SHOWERS OVER THE MOUNTAINS.

NEXT COLD FRONT LOOKS TO MOVE INTO THE AREA MONDAY AFTERNOON INTO
TUESDAY. ECMWF A LITTLE COLDER THAN GFS IN 700MB
TEMPERATURES...BUT NOT AS BAD AS A FEW DAYS AGO. PROBABLY NEED TO
GO COLDER WITH THIS SETUP. DISCREPANCY MUCH GREATER ON TUESDAY
WITH THE ECMWF FORECASTING 700MB TEMPERATURES OF +4 TO +6C AND GFS
SHOWING +10 TO +12C.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY MORNING)
ISSUED AT 330 PM MDT WED AUG 20 2014

FOLLOWED LATEST HRRR GUIDANCE FOR TIMING ON SHOWERS AND
THUNDERSTORMS FOR SOUTHEAST WYOMING AND NEBRASKA PANHANDLE
AIRPORTS THIS AFTERNOON. HRRR HAS BEEN DOING WELL ON THE EARLY
MORNING CONVECTION...SO SEE NO REASON TO DEVIATE.

&&

.FIRE WEATHER...
ISSUED AT 156 PM MDT WED AUG 20 2014

MINIMAL FIRE WEATHER CONCERNS INTO EARLY NEXT WEEK. SUBTROPICAL
MOISTURE WILL REMAIN OVER THE AREA THROUGH THE WEEKEND WITH
SHOWERS AND THUNDERSTORMS POSSIBLE EACH DAY ACROSS SOUTHEAST
WYOMING AND WESTERN NEBRASKA. THERE IS A GOOD CHANCE OF WETTING
RAINS BY FRIDAY AND THIS WEEKEND AS THUNDERSTORM COVERAGE WILL BE
HIGHER. TEMPERATURES WILL TREND COOLER BY LATE THIS WEEK AND INTO
THIS WEEKEND AS A STRONG COLD FRONT FOR THIS TIME OF THE YEAR
MOVES INTO THE REGION LATE ON SATURDAY.



&&

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

$$

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











000
FXUS65 KCYS 201634
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
1034 AM MDT WED AUG 20 2014

.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 350 AM MDT WED AUG 20 2014

INITIAL SHORTWAVE TROUGH ALOFT MOVES ACROSS OUR COUNTIES
EARLY IN THE DAY...WITH A WEAKER...SECONDARY SHORTWAVE TROUGH
APPROACHING OUR WESTERN COUNTIES IN THE LATE AFTERNOON. SOME LOW
LEVEL DRYING NOTED IN THE WAKE OF THE MORNING SHORTWAVE TROUGH...
THOUGH IT APPEARS THERE WILL BE ENOUGH LOW AND MID LEVEL MOISTURE
THIS AFTERNOON TO SPARK ISOLATED TO SCATTERED SHOWERS AND
THUNDERSTORMS...MOST NUMEROUS WEST OF INTERSTATE 25.

TONIGHT...SHOWERS AND THUNDERSTORMS ENDING IN THE EVENING WITH THE
LOSS OF DAYTIME HEATING AND ABSENCE OF ANY OTHER LIFTING MECHANISMS.

THURSDAY...SOUTHWEST FLOW ALOFT CONTINUES AND WITH ADEQUATE LOW AND
MID LEVEL MOISTURE IN PLACE...WILL SEE ISOLATED LATE DAY
THUNDERSTORMS ALONG AND WEST OF A LUSK TO CHEYENNE LINE.

THURSDAY NIGHT...WEAK COLD FRONT ENTERS FROM THE NORTH...THOUGH WITH
MINIMAL LOW AND MID LEVEL MOISTURE...RAIN CHANCES WILL BE SLIM. LATE
IN THE NIGHT...WILL GO WITH ISOLATED SHOWERS AFTER MIDNIGHT EAST OF
A DOUGLAS TO SIDNEY LINE IN LOW LEVEL CONVERGENCE BOUNDARY.

FRIDAY...INCREASED CHANCE FOR SHOWERS AND THUNDERSTORMS OVER
THURSDAY AS A NEGATIVELY TILTED SHORTWAVE TROUGH ALOFT PROPAGATES
ACROSS OUR WESTERN NEBRASKA COUNTIES...WITH ENHANCED SOUTHEAST LOW
LEVEL WINDS ADVECTING MOISTURE IN...AND PROVIDING MECHANICAL LIFT TO
HELP GENERATE THUNDERSTORMS.

.LONG TERM...(FRIDAY NIGHT THROUGH TUESDAY)
ISSUED AT 350 AM MDT WED AUG 20 2014

00Z MEDIUM RANGE GUIDANCE ARE CONSISTENT IN SWINGING AN UPPER
TROUGH THRU THE NRN ROCKIES OVR THE WEEKEND. THIS IS AN EARLY
INDICATION OF THE SEASONAL PATTERN CHANGE THAT WILL CONTINUE OVR
THE NEXT FEW MONTHS. SATURDAY STILL LOOKS RELATIVELY WARM IN THE
PREFRONTAL AIR MASS...ESPECIALLY OVR THE ERN PLAINS. MODELS PROG
1000-1500 J/KG AHEAD OF THE FRONT SATURDAY AFTERNOON. THE
FAVORABLE THERMODYNAMIC PROFILE COMBINED WITH THE PROXIMITY OF RRQ
OF A JET STREAK SUGGESTS AT LEAST THE POSSIBILITY OF A FEW
STRONGER STORMS OVR THE PLAINS SATURDAY AFTERNOON. OF
COURSE...MUCH OF THIS SCENARIO IS DEPENDENT UPON THE CURRENT
TIMING OF LATE SATURDAY AND SATURDAY EVENING FROPA. CONVECTION
WILL TURN MORE SHOWERY IN THE WAKE OF THE FRONT SATURDAY NIGHT.
SUNDAY WILL BE NOTICEABLY COOLER POST-FRONTAL WITH HIGHS ONLY
REACHING 70S AT MOST LOCATIONS. LEFT MOSTLY SHOWER CHANCES ALONG
WITH ISOLD THUNDER MENTION GOING FOR SUNDAY. THIS WILL DEPEND UPON
JUST HOW MUCH CLEARING OCCURS. TEMPERATURES RETURN TO MORE
SEASONAL VALUES FOR MON-TUE TIMEFRAME. HARD TO REMOVE MENTION OF
DAILY AFTERNOON AND EVENING CONVECTION EARLY NEXT WEEK AS
PERSISTENT SOUTHWEST FLOW EJECTS IMPOSSIBLE TO TIME EMBEDDED
SHORTWAVES. PRECIP DEFINITELY WONT BE AN ALL DAY OCCURRENCE...BUT
CANT RULE OUT ITS POSSIBILITY MAINLY DURING THE AFTERNOON AND
EVENING HOURS. THE PATTERN LOOKS TO TREND DRIER FOR THE LATTER
HALF OF NEXT WEEK.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY MORNING)
ISSUED AT 1033 AM MDT WED AUG 20 2014

FOLLOWED LATEST HRRR GUIDANCE FOR TIMING ON SHOWERS AND
THUNDERSTORMS FOR SOUTHEAST WYOMING AND NEBRASKA PANHANDLE
AIRPORTS THIS AFTERNOON. HRRR HAS BEEN DOING WELL ON THE EARLY
MORNING CONVECTION...SO SEE NO REASON TO DEVIATE.

&&

.FIRE WEATHER...
ISSUED AT 350 AM MDT WED AUG 20 2014

HUMIDITIES AND WINDS WILL REMAIN BELOW CRITICAL THRESHOLDS THE
NEXT FEW DAYS...THUS MINIMAL FIRE WEATHER CONCERNS.

&&

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

$$

SHORT TERM...RUBIN
LONG TERM...HAHN
AVIATION...CLAYCOMB
FIRE WEATHER...RUBIN







000
FXUS65 KCYS 201634
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
1034 AM MDT WED AUG 20 2014

.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 350 AM MDT WED AUG 20 2014

INITIAL SHORTWAVE TROUGH ALOFT MOVES ACROSS OUR COUNTIES
EARLY IN THE DAY...WITH A WEAKER...SECONDARY SHORTWAVE TROUGH
APPROACHING OUR WESTERN COUNTIES IN THE LATE AFTERNOON. SOME LOW
LEVEL DRYING NOTED IN THE WAKE OF THE MORNING SHORTWAVE TROUGH...
THOUGH IT APPEARS THERE WILL BE ENOUGH LOW AND MID LEVEL MOISTURE
THIS AFTERNOON TO SPARK ISOLATED TO SCATTERED SHOWERS AND
THUNDERSTORMS...MOST NUMEROUS WEST OF INTERSTATE 25.

TONIGHT...SHOWERS AND THUNDERSTORMS ENDING IN THE EVENING WITH THE
LOSS OF DAYTIME HEATING AND ABSENCE OF ANY OTHER LIFTING MECHANISMS.

THURSDAY...SOUTHWEST FLOW ALOFT CONTINUES AND WITH ADEQUATE LOW AND
MID LEVEL MOISTURE IN PLACE...WILL SEE ISOLATED LATE DAY
THUNDERSTORMS ALONG AND WEST OF A LUSK TO CHEYENNE LINE.

THURSDAY NIGHT...WEAK COLD FRONT ENTERS FROM THE NORTH...THOUGH WITH
MINIMAL LOW AND MID LEVEL MOISTURE...RAIN CHANCES WILL BE SLIM. LATE
IN THE NIGHT...WILL GO WITH ISOLATED SHOWERS AFTER MIDNIGHT EAST OF
A DOUGLAS TO SIDNEY LINE IN LOW LEVEL CONVERGENCE BOUNDARY.

FRIDAY...INCREASED CHANCE FOR SHOWERS AND THUNDERSTORMS OVER
THURSDAY AS A NEGATIVELY TILTED SHORTWAVE TROUGH ALOFT PROPAGATES
ACROSS OUR WESTERN NEBRASKA COUNTIES...WITH ENHANCED SOUTHEAST LOW
LEVEL WINDS ADVECTING MOISTURE IN...AND PROVIDING MECHANICAL LIFT TO
HELP GENERATE THUNDERSTORMS.

.LONG TERM...(FRIDAY NIGHT THROUGH TUESDAY)
ISSUED AT 350 AM MDT WED AUG 20 2014

00Z MEDIUM RANGE GUIDANCE ARE CONSISTENT IN SWINGING AN UPPER
TROUGH THRU THE NRN ROCKIES OVR THE WEEKEND. THIS IS AN EARLY
INDICATION OF THE SEASONAL PATTERN CHANGE THAT WILL CONTINUE OVR
THE NEXT FEW MONTHS. SATURDAY STILL LOOKS RELATIVELY WARM IN THE
PREFRONTAL AIR MASS...ESPECIALLY OVR THE ERN PLAINS. MODELS PROG
1000-1500 J/KG AHEAD OF THE FRONT SATURDAY AFTERNOON. THE
FAVORABLE THERMODYNAMIC PROFILE COMBINED WITH THE PROXIMITY OF RRQ
OF A JET STREAK SUGGESTS AT LEAST THE POSSIBILITY OF A FEW
STRONGER STORMS OVR THE PLAINS SATURDAY AFTERNOON. OF
COURSE...MUCH OF THIS SCENARIO IS DEPENDENT UPON THE CURRENT
TIMING OF LATE SATURDAY AND SATURDAY EVENING FROPA. CONVECTION
WILL TURN MORE SHOWERY IN THE WAKE OF THE FRONT SATURDAY NIGHT.
SUNDAY WILL BE NOTICEABLY COOLER POST-FRONTAL WITH HIGHS ONLY
REACHING 70S AT MOST LOCATIONS. LEFT MOSTLY SHOWER CHANCES ALONG
WITH ISOLD THUNDER MENTION GOING FOR SUNDAY. THIS WILL DEPEND UPON
JUST HOW MUCH CLEARING OCCURS. TEMPERATURES RETURN TO MORE
SEASONAL VALUES FOR MON-TUE TIMEFRAME. HARD TO REMOVE MENTION OF
DAILY AFTERNOON AND EVENING CONVECTION EARLY NEXT WEEK AS
PERSISTENT SOUTHWEST FLOW EJECTS IMPOSSIBLE TO TIME EMBEDDED
SHORTWAVES. PRECIP DEFINITELY WONT BE AN ALL DAY OCCURRENCE...BUT
CANT RULE OUT ITS POSSIBILITY MAINLY DURING THE AFTERNOON AND
EVENING HOURS. THE PATTERN LOOKS TO TREND DRIER FOR THE LATTER
HALF OF NEXT WEEK.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY MORNING)
ISSUED AT 1033 AM MDT WED AUG 20 2014

FOLLOWED LATEST HRRR GUIDANCE FOR TIMING ON SHOWERS AND
THUNDERSTORMS FOR SOUTHEAST WYOMING AND NEBRASKA PANHANDLE
AIRPORTS THIS AFTERNOON. HRRR HAS BEEN DOING WELL ON THE EARLY
MORNING CONVECTION...SO SEE NO REASON TO DEVIATE.

&&

.FIRE WEATHER...
ISSUED AT 350 AM MDT WED AUG 20 2014

HUMIDITIES AND WINDS WILL REMAIN BELOW CRITICAL THRESHOLDS THE
NEXT FEW DAYS...THUS MINIMAL FIRE WEATHER CONCERNS.

&&

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

$$

SHORT TERM...RUBIN
LONG TERM...HAHN
AVIATION...CLAYCOMB
FIRE WEATHER...RUBIN








000
FXUS65 KCYS 201214
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
614 AM MDT WED AUG 20 2014

.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 350 AM MDT WED AUG 20 2014

INITIAL SHORTWAVE TROUGH ALOFT MOVES ACROSS OUR COUNTIES
EARLY IN THE DAY...WITH A WEAKER...SECONDARY SHORTWAVE TROUGH
APPROACHING OUR WESTERN COUNTIES IN THE LATE AFTERNOON. SOME LOW
LEVEL DRYING NOTED IN THE WAKE OF THE MORNING SHORTWAVE TROUGH...
THOUGH IT APPEARS THERE WILL BE ENOUGH LOW AND MID LEVEL MOISTURE
THIS AFTERNOON TO SPARK ISOLATED TO SCATTERED SHOWERS AND
THUNDERSTORMS...MOST NUMEROUS WEST OF INTERSTATE 25.

TONIGHT...SHOWERS AND THUNDERSTORMS ENDING IN THE EVENING WITH THE
LOSS OF DAYTIME HEATING AND ABSENCE OF ANY OTHER LIFTING MECHANISMS.

THURSDAY...SOUTHWEST FLOW ALOFT CONTINUES AND WITH ADEQUATE LOW AND
MID LEVEL MOISTURE IN PLACE...WILL SEE ISOLATED LATE DAY
THUNDERSTORMS ALONG AND WEST OF A LUSK TO CHEYENNE LINE.

THURSDAY NIGHT...WEAK COLD FRONT ENTERS FROM THE NORTH...THOUGH WITH
MINIMAL LOW AND MID LEVEL MOISTURE...RAIN CHANCES WILL BE SLIM. LATE
IN THE NIGHT...WILL GO WITH ISOLATED SHOWERS AFTER MIDNIGHT EAST OF
A DOUGLAS TO SIDNEY LINE IN LOW LEVEL CONVERGENCE BOUNDARY.

FRIDAY...INCREASED CHANCE FOR SHOWERS AND THUNDERSTORMS OVER
THURSDAY AS A NEGATIVELY TILTED SHORTWAVE TROUGH ALOFT PROPAGATES
ACROSS OUR WESTERN NEBRASKA COUNTIES...WITH ENHANCED SOUTHEAST LOW
LEVEL WINDS ADVECTING MOISTURE IN...AND PROVIDING MECHANICAL LIFT TO
HELP GENERATE THUNDERSTORMS.

.LONG TERM...(FRIDAY NIGHT THROUGH TUESDAY)
ISSUED AT 350 AM MDT WED AUG 20 2014

00Z MEDIUM RANGE GUIDANCE ARE CONSISTENT IN SWINGING AN UPPER
TROUGH THRU THE NRN ROCKIES OVR THE WEEKEND. THIS IS AN EARLY
INDICATION OF THE SEASONAL PATTERN CHANGE THAT WILL CONTINUE OVR
THE NEXT FEW MONTHS. SATURDAY STILL LOOKS RELATIVELY WARM IN THE
PREFRONTAL AIR MASS...ESPECIALLY OVR THE ERN PLAINS. MODELS PROG
1000-1500 J/KG AHEAD OF THE FRONT SATURDAY AFTERNOON. THE
FAVORABLE THERMODYNAMIC PROFILE COMBINED WITH THE PROXIMITY OF RRQ
OF A JET STREAK SUGGESTS AT LEAST THE POSSIBILITY OF A FEW
STRONGER STORMS OVR THE PLAINS SATURDAY AFTERNOON. OF
COURSE...MUCH OF THIS SCENARIO IS DEPENDENT UPON THE CURRENT
TIMING OF LATE SATURDAY AND SATURDAY EVENING FROPA. CONVECTION
WILL TURN MORE SHOWERY IN THE WAKE OF THE FRONT SATURDAY NIGHT.
SUNDAY WILL BE NOTICEABLY COOLER POST-FRONTAL WITH HIGHS ONLY
REACHING 70S AT MOST LOCATIONS. LEFT MOSTLY SHOWER CHANCES ALONG
WITH ISOLD THUNDER MENTION GOING FOR SUNDAY. THIS WILL DEPEND UPON
JUST HOW MUCH CLEARING OCCURS. TEMPERATURES RETURN TO MORE
SEASONAL VALUES FOR MON-TUE TIMEFRAME. HARD TO REMOVE MENTION OF
DAILY AFTERNOON AND EVENING CONVECTION EARLY NEXT WEEK AS
PERSISTENT SOUTHWEST FLOW EJECTS IMPOSSIBLE TO TIME EMBEDDED
SHORTWAVES. PRECIP DEFINITELY WONT BE AN ALL DAY OCCURRENCE...BUT
CANT RULE OUT ITS POSSIBILITY MAINLY DURING THE AFTERNOON AND
EVENING HOURS. THE PATTERN LOOKS TO TREND DRIER FOR THE LATTER
HALF OF NEXT WEEK.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 613 AM MDT WED AUG 20 2014

THE MAIN CHALLENGE WITH THE TAF FORECAST FOCUSES ON CONVECTIVE
TIMING BOTH INITIALLY THIS MORNING AND AGAIN THIS AFTERNOON.
MORNING RADAR RETURNS SHOWS A BATCH OF LIGHT RAIN SHOWERS LIFT
NORTHEAST ACROSS THE AREA. KRWL HAD DROPPED TO MVFR VERY BRIEFLY
EARLIER THIS MORNING...BUT HAVE REMAINED VFR SINCE. HAVE KEPT VFR
CONDITIONS IN PLACE EVERYWHERE THRU THE PERIOD. THIS INITIAL BATCH
OF SHOWERS WILL EXIT THE AREA BY MID-MORNING...WITH ANOTHER ROUND
OF ISOLD AFTERNOON AND EVENING SHOWERS/STORMS POSSIBLE. HAVE ADDED
VCTS TO MOST SITES TO CAPTURE THIS IDEA THIS AFTERNOON. THIS
ACTIVITY WILL DISSIPATE BETWEEN 02-03Z.

&&

.FIRE WEATHER...
ISSUED AT 350 AM MDT WED AUG 20 2014

HUMIDITIES AND WINDS WILL REMAIN BELOW CRITICAL THRESHOLDS THE
NEXT FEW DAYS...THUS MINIMAL FIRE WEATHER CONCERNS.

&&

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

$$

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








000
FXUS65 KCYS 201214
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
614 AM MDT WED AUG 20 2014

.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 350 AM MDT WED AUG 20 2014

INITIAL SHORTWAVE TROUGH ALOFT MOVES ACROSS OUR COUNTIES
EARLY IN THE DAY...WITH A WEAKER...SECONDARY SHORTWAVE TROUGH
APPROACHING OUR WESTERN COUNTIES IN THE LATE AFTERNOON. SOME LOW
LEVEL DRYING NOTED IN THE WAKE OF THE MORNING SHORTWAVE TROUGH...
THOUGH IT APPEARS THERE WILL BE ENOUGH LOW AND MID LEVEL MOISTURE
THIS AFTERNOON TO SPARK ISOLATED TO SCATTERED SHOWERS AND
THUNDERSTORMS...MOST NUMEROUS WEST OF INTERSTATE 25.

TONIGHT...SHOWERS AND THUNDERSTORMS ENDING IN THE EVENING WITH THE
LOSS OF DAYTIME HEATING AND ABSENCE OF ANY OTHER LIFTING MECHANISMS.

THURSDAY...SOUTHWEST FLOW ALOFT CONTINUES AND WITH ADEQUATE LOW AND
MID LEVEL MOISTURE IN PLACE...WILL SEE ISOLATED LATE DAY
THUNDERSTORMS ALONG AND WEST OF A LUSK TO CHEYENNE LINE.

THURSDAY NIGHT...WEAK COLD FRONT ENTERS FROM THE NORTH...THOUGH WITH
MINIMAL LOW AND MID LEVEL MOISTURE...RAIN CHANCES WILL BE SLIM. LATE
IN THE NIGHT...WILL GO WITH ISOLATED SHOWERS AFTER MIDNIGHT EAST OF
A DOUGLAS TO SIDNEY LINE IN LOW LEVEL CONVERGENCE BOUNDARY.

FRIDAY...INCREASED CHANCE FOR SHOWERS AND THUNDERSTORMS OVER
THURSDAY AS A NEGATIVELY TILTED SHORTWAVE TROUGH ALOFT PROPAGATES
ACROSS OUR WESTERN NEBRASKA COUNTIES...WITH ENHANCED SOUTHEAST LOW
LEVEL WINDS ADVECTING MOISTURE IN...AND PROVIDING MECHANICAL LIFT TO
HELP GENERATE THUNDERSTORMS.

.LONG TERM...(FRIDAY NIGHT THROUGH TUESDAY)
ISSUED AT 350 AM MDT WED AUG 20 2014

00Z MEDIUM RANGE GUIDANCE ARE CONSISTENT IN SWINGING AN UPPER
TROUGH THRU THE NRN ROCKIES OVR THE WEEKEND. THIS IS AN EARLY
INDICATION OF THE SEASONAL PATTERN CHANGE THAT WILL CONTINUE OVR
THE NEXT FEW MONTHS. SATURDAY STILL LOOKS RELATIVELY WARM IN THE
PREFRONTAL AIR MASS...ESPECIALLY OVR THE ERN PLAINS. MODELS PROG
1000-1500 J/KG AHEAD OF THE FRONT SATURDAY AFTERNOON. THE
FAVORABLE THERMODYNAMIC PROFILE COMBINED WITH THE PROXIMITY OF RRQ
OF A JET STREAK SUGGESTS AT LEAST THE POSSIBILITY OF A FEW
STRONGER STORMS OVR THE PLAINS SATURDAY AFTERNOON. OF
COURSE...MUCH OF THIS SCENARIO IS DEPENDENT UPON THE CURRENT
TIMING OF LATE SATURDAY AND SATURDAY EVENING FROPA. CONVECTION
WILL TURN MORE SHOWERY IN THE WAKE OF THE FRONT SATURDAY NIGHT.
SUNDAY WILL BE NOTICEABLY COOLER POST-FRONTAL WITH HIGHS ONLY
REACHING 70S AT MOST LOCATIONS. LEFT MOSTLY SHOWER CHANCES ALONG
WITH ISOLD THUNDER MENTION GOING FOR SUNDAY. THIS WILL DEPEND UPON
JUST HOW MUCH CLEARING OCCURS. TEMPERATURES RETURN TO MORE
SEASONAL VALUES FOR MON-TUE TIMEFRAME. HARD TO REMOVE MENTION OF
DAILY AFTERNOON AND EVENING CONVECTION EARLY NEXT WEEK AS
PERSISTENT SOUTHWEST FLOW EJECTS IMPOSSIBLE TO TIME EMBEDDED
SHORTWAVES. PRECIP DEFINITELY WONT BE AN ALL DAY OCCURRENCE...BUT
CANT RULE OUT ITS POSSIBILITY MAINLY DURING THE AFTERNOON AND
EVENING HOURS. THE PATTERN LOOKS TO TREND DRIER FOR THE LATTER
HALF OF NEXT WEEK.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 613 AM MDT WED AUG 20 2014

THE MAIN CHALLENGE WITH THE TAF FORECAST FOCUSES ON CONVECTIVE
TIMING BOTH INITIALLY THIS MORNING AND AGAIN THIS AFTERNOON.
MORNING RADAR RETURNS SHOWS A BATCH OF LIGHT RAIN SHOWERS LIFT
NORTHEAST ACROSS THE AREA. KRWL HAD DROPPED TO MVFR VERY BRIEFLY
EARLIER THIS MORNING...BUT HAVE REMAINED VFR SINCE. HAVE KEPT VFR
CONDITIONS IN PLACE EVERYWHERE THRU THE PERIOD. THIS INITIAL BATCH
OF SHOWERS WILL EXIT THE AREA BY MID-MORNING...WITH ANOTHER ROUND
OF ISOLD AFTERNOON AND EVENING SHOWERS/STORMS POSSIBLE. HAVE ADDED
VCTS TO MOST SITES TO CAPTURE THIS IDEA THIS AFTERNOON. THIS
ACTIVITY WILL DISSIPATE BETWEEN 02-03Z.

&&

.FIRE WEATHER...
ISSUED AT 350 AM MDT WED AUG 20 2014

HUMIDITIES AND WINDS WILL REMAIN BELOW CRITICAL THRESHOLDS THE
NEXT FEW DAYS...THUS MINIMAL FIRE WEATHER CONCERNS.

&&

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

$$

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







000
FXUS65 KCYS 200951
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
351 AM MDT WED AUG 20 2014

.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 350 AM MDT WED AUG 20 2014

INITIAL SHORTWAVE TROUGH ALOFT MOVES ACROSS OUR COUNTIES
EARLY IN THE DAY...WITH A WEAKER...SECONDARY SHORTWAVE TROUGH
APPROACHING OUR WESTERN COUNTIES IN THE LATE AFTERNOON. SOME LOW
LEVEL DRYING NOTED IN THE WAKE OF THE MORNING SHORTWAVE TROUGH...
THOUGH IT APPEARS THERE WILL BE ENOUGH LOW AND MID LEVEL MOISTURE
THIS AFTERNOON TO SPARK ISOLATED TO SCATTERED SHOWERS AND
THUNDERSTORMS...MOST NUMEROUS WEST OF INTERSTATE 25.

TONIGHT...SHOWERS AND THUNDERSTORMS ENDING IN THE EVENING WITH THE
LOSS OF DAYTIME HEATING AND ABSENCE OF ANY OTHER LIFTING MECHANISMS.

THURSDAY...SOUTHWEST FLOW ALOFT CONTINUES AND WITH ADEQUATE LOW AND
MID LEVEL MOISTURE IN PLACE...WILL SEE ISOLATED LATE DAY
THUNDERSTORMS ALONG AND WEST OF A LUSK TO CHEYENNE LINE.

THURSDAY NIGHT...WEAK COLD FRONT ENTERS FROM THE NORTH...THOUGH WITH
MINIMAL LOW AND MID LEVEL MOISTURE...RAIN CHANCES WILL BE SLIM. LATE
IN THE NIGHT...WILL GO WITH ISOLATED SHOWERS AFTER MIDNIGHT EAST OF
A DOUGLAS TO SIDNEY LINE IN LOW LEVEL CONVERGENCE BOUNDARY.

FRIDAY...INCREASED CHANCE FOR SHOWERS AND THUNDERSTORMS OVER
THURSDAY AS A NEGATIVELY TILTED SHORTWAVE TROUGH ALOFT PROPAGATES
ACROSS OUR WESTERN NEBRASKA COUNTIES...WITH ENHANCED SOUTHEAST LOW
LEVEL WINDS ADVECTING MOISTURE IN...AND PROVIDING MECHANICAL LIFT TO
HELP GENERATE THUNDERSTORMS.

.LONG TERM...(FRIDAY NIGHT THROUGH TUESDAY)
ISSUED AT 350 AM MDT WED AUG 20 2014

00Z MEDIUM RANGE GUIDANCE ARE CONSISTENT IN SWINGING AN UPPER
TROUGH THRU THE NRN ROCKIES OVR THE WEEKEND. THIS IS AN EARLY
INDICATION OF THE SEASONAL PATTERN CHANGE THAT WILL CONTINUE OVR
THE NEXT FEW MONTHS. SATURDAY STILL LOOKS RELATIVELY WARM IN THE
PREFRONTAL AIR MASS...ESPECIALLY OVR THE ERN PLAINS. MODELS PROG
1000-1500 J/KG AHEAD OF THE FRONT SATURDAY AFTERNOON. THE
FAVORABLE THERMODYNAMIC PROFILE COMBINED WITH THE PROXIMITY OF RRQ
OF A JET STREAK SUGGESTS AT LEAST THE POSSIBILITY OF A FEW
STRONGER STORMS OVR THE PLAINS SATURDAY AFTERNOON. OF
COURSE...MUCH OF THIS SCENARIO IS DEPENDENT UPON THE CURRENT
TIMING OF LATE SATURDAY AND SATURDAY EVENING FROPA. CONVECTION
WILL TURN MORE SHOWERY IN THE WAKE OF THE FRONT SATURDAY NIGHT.
SUNDAY WILL BE NOTICEABLY COOLER POST-FRONTAL WITH HIGHS ONLY
REACHING 70S AT MOST LOCATIONS. LEFT MOSTLY SHOWER CHANCES ALONG
WITH ISOLD THUNDER MENTION GOING FOR SUNDAY. THIS WILL DEPEND UPON
JUST HOW MUCH CLEARING OCCURS. TEMPERATURES RETURN TO MORE
SEASONAL VALUES FOR MON-TUE TIMEFRAME. HARD TO REMOVE MENTION OF
DAILY AFTERNOON AND EVENING CONVECTION EARLY NEXT WEEK AS
PERSISTENT SOUTHWEST FLOW EJECTS IMPOSSIBLE TO TIME EMBEDDED
SHORTWAVES. PRECIP DEFINITELY WONT BE AN ALL DAY OCCURRENCE...BUT
CANT RULE OUT ITS POSSIBILITY MAINLY DURING THE AFTERNOON AND
EVENING HOURS. THE PATTERN LOOKS TO TREND DRIER FOR THE LATTER
HALF OF NEXT WEEK.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1215 AM MDT WED AUG 20 2014

SHOWERS WILL INCREASE FROM WEST TO EAST ACROSS THE AREA TONIGHT.
VFR CONDITIONS ARE EXPECTED FOR MOST TERMINALS WITH CIGS BETWEEN
5K AND 10K FEET AGL. BRIEF MVFR CIGS OR VSBYS COULD OCCUR WITH ANY
HEAVIER PRECIPITATION AFTER 06Z. ISOLATED SHOWERS OR WEAK TSTMS
COULD BE IN THE VICINITY OF MOST TERMINALS THROUGH MOST OF THE TAF
PERIOD. WINDS WILL GENERALLY BE BELOW 15 KTS...EXCEPT GUSTY AND
VARIABLE NEAR ANY SHOWERS.

&&

.FIRE WEATHER...
ISSUED AT 350 AM MDT WED AUG 20 2014

HUMIDITIES AND WINDS WILL REMAIN BELOW CRITICAL THRESHOLDS THE
NEXT FEW DAYS...THUS MINIMAL FIRE WEATHER CONCERNS.

&&

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

&&

$$

SHORT TERM...RUBIN
LONG TERM...HAHN
AVIATION...HAMMER
FIRE WEATHER...RUBIN







000
FXUS65 KCYS 200616
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
1216 AM MDT WED AUG 20 2014

.UPDATE...
ISSUED AT 958 PM MDT TUE AUG 19 2014

STRONG TO SEVERE THUNDERSTORM CHANCES HAVE ENDED FOR THE REST OF
TONIGHT. WILL MAINLY SEE SCATTERED SHOWERS AND ISOLATED
THUNDERSTORMS THE REST OF TONIGHT.

&&

.SHORT TERM...(TONIGHT THROUGH THURSDAY NIGHT)
ISSUED AT 250 PM MDT TUE AUG 19 2014

THE MAIN CONCERN WITH THIS FORECAST PACKAGE IS WHERE THE
CONVECTION WILL BREAK OUT THIS AFTERNOON AND HOW MUCH CONVECTION
WILL BREAK OUT AHEAD OF THE JET STREAK MOVING ACROSS THE ROCKIES
TONIGHT.

LATEST VISIBLE IMAGERY WAS SHOWING SOME ACCAS DEVELOPING ACROSS NORTHEAST
COLORADO NEAR THE SURFACE TROF. THIS AREA MAY END UP BEING THE
FIRST AREA TO FIRE UP THIS AFTERNOON. HOWEVER...IT MAY TRY TO
IGNITE JUST EAST OF THE LARAMIE AND FRONT RANGES AS WELL WHERE WE
HAVE HAD QUITE A BIT OF SUNSHINE. IN FACT...WE ARE STARTING TO SEE
A LITTLE BIT OF ACCAS OVERHEAD AND CONVECTION DEVELOPING ALONG THE
FRONT RANGE. MODELS ARE PROJECTING MIXED LAYER CAPES TO APPROACH 1500
J/KG THIS AFTERNOON WITH VERY LIMITED CAP. 0-6KM SHEAR VALUES
(~30KTS) MAY ALSO BE FAVORABLE FOR A FEW STRONG TO SEVERE STORMS.
AT THIS POINT...IT LOOKS THE HRRR IS STARTING TO BREAK OUT
CONVECTION JUST EAST OF CHEYENNE AFTER 21Z WITH THE BULK OF THIS
CONVECTION PUSHING GENERALLY EAST AT AROUND 20KTS. A FEW OF THESE
STORMS MAY HAVE THE POTENTIAL TO PRODUCING STRONG WINDS AND HAIL IN THE
PANHANDLE THIS AFTERNOON. LATEST SURFACE ANALYSIS WAS ALSO SHOWING
SOME WINDS BACKING TO THE SOUTHEAST IN THE PANHANDLE. WE WILL ALSO
NEED TO WATCH THAT AS THE AFTERNOON WEARS ON...ESPECIALLY IF THE
STORMS GET GOING IN THAT REGION.

ANOTHER CONCERN IS THE NAM IS SHOWING A 500MB JET STREAK MOVING
OUT OF NORTHEAST COLORADO EARLY THIS EVENING WHICH MAY HELP
ENHANCE THE SHEAR ACROSS THE PANHANDLE. IF CONVECTION IS ON GOING
IN THAT REGION AS THIS JET STREAK MOVES ACROSS WE MAY HAVE MORE OF
A SEVERE POTENTIAL. THEREFORE...IT WILL BE A MATTER OF TIMING ON
HOW THINGS COME TOGETHER LATE THIS AFTERNOON AND EVENING.

TONIGHT THE MODELS ARE SHOWING A FAIRLY STRONG UPPER LEVEL JET
MOVING THROUGH NORTHERN COLORADO AND LIFTING NORTHEAST INTO
NORTHEAST WYOMING BY DAYBREAK WHICH WILL HELP ENHANCE UPPER LEVEL
DIFFLUENCE. THE MODELS ARE EVEN IN FAIRLY GOOD AGREEMENT IN
SHOWING A MID LEVEL CIRCULATION WITH THIS JET STREAK. AS A
RESULT... WE WOULD NOT SURPRISED TO SEE A COMPLEX OF SHOWERS AND
THUNDERSTORMS DEVELOP ACROSS THE WESTERN HALF OF THE FORECAST AREA
OVERNIGHT ALONG WITH THE POTENTIAL FOR HEAVY RAINFALL DUE TO PRECIPITABLE
WATER VALUES AROUND 1 INCH. NOT EXPECTING MUCH IN THE WAY OF
FLOODING SINCE THIS COMPLEX SHOULD BE FAIRLY PROGRESSIVE. WE DID
BUMP UP POPS ACROSS THE NORTHERN HALF OF THE AREA TONIGHT TO
REFLECT THIS POTENTIAL.

WEDNESDAY-THURSDAY NIGHT:
THE MID LEVEL CIRCULATION IS PROGGED TO CONTINUE LIFTING NORTHEAST
WHICH WILL TAKE THE BULK OF THE CONVECTION NORTHEAST OF THE
FORECAST AREA BY MID MORNING. THIS WILL LEAVE A FAIRLY BROAD AREA OF
SUBSIDENCE IN THE MORNING IN THE WAKE OF THE CONVECTION...BUT WE
MAY MORE CONVECTION DEVELOP IN THE AFTERNOON ACROSS THE MOUNTAINS
AS UPSLOPE FLOW COMMENCES WITH LEFTOVER RESIDUAL MOISTURE.
OTHERWISE...THE REMAINDER OF THE AREA EAST OF THE LARAMIE RANGE
SHOULD REMAIN FAIRLY DRY WITH HIGHS GENERALLY IN THE 80S. THE
NEXT CHANCE OF SHOWERS AND THUNDERSTORMS IS PROGGED TO TAKE PLACE
ON THURSDAY AFTERNOON AS ANOTHER UPPER LEVEL WAVE LIFTS NORTHEAST
OUT OF COLORADO AND PUSHES THROUGH AREAS EAST OF THE LARAMIE RANGE
THURSDAY AFTERNOON INTO THURSDAY NIGHT.

.LONG TERM...(FRIDAY THROUGH TUESDAY)
ISSUED AT 250 PM MDT TUE AUG 19 2014

AN UPPER LOW AND ASSOCIATED TROUGH OVER THE PACIFIC NW FRIDAY WILL
MOVE SLOWLY EAST TOWARDS THE AREA FRIDAY THROUGH SATURDAY...
SWINGING BY THE AREA ON SUNDAY. THIS WILL COMBINE WITH AT LEAST
RESIDUAL MONSOONAL MOISTURE TO KEEP CHANCES FOR SHOWERS AND TSTMS
GOING OVER MOST AREAS THROUGH SATURDAY NIGHT. WILL CONTINUE TO
LEAN TOWARDS THE EC SOLUTION AS IT HAS BEEN FAIRLY CONSISTENT WITH
THIS FEATURE. WARM TEMPS WILL CONTINUE THROUGH SATURDAY THEN A
DECENT COOL FRONT WILL PASS ACROSS SAT NIGHT LEAVING A DRIER AND
MILD DAY FOR THE CWA SUNDAY. CONTINUED MILD ON MONDAY WITH THE CWA
ON THE SOUTHERN PORTION OF BROAD CYCLONIC UPPER FLOW THAT WILL BE
OVER THE NORTHERN PART OF THE COUNTRY. A SECOND UPPER SHORTWAVE
SHOULD PASS BY TUESDAY BRINGING A REINFORCING SHOT OF COOLER AIR
AND A CHANCE FOR SOME PRECIPITATION.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1215 AM MDT WED AUG 20 2014

SHOWERS WILL INCREASE FROM WEST TO EAST ACROSS THE AREA TONIGHT.
VFR CONDITIONS ARE EXPECTED FOR MOST TERMINALS WITH CIGS BETWEEN
5K AND 10K FEET AGL. BRIEF MVFR CIGS OR VSBYS COULD OCCUR WITH ANY
HEAVIER PRECIPITATION AFTER 06Z. ISOLATED SHOWERS OR WEAK TSTMS
COULD BE IN THE VICINITY OF MOST TERMINALS THROUGH MOST OF THE TAF
PERIOD. WINDS WILL GENERALLY BE BELOW 15 KTS...EXCEPT GUSTY AND
VARIABLE NEAR ANY SHOWERS.

&&

.FIRE WEATHER...
ISSUED AT 1056 AM MDT TUE AUG 19 2014

FIRE WEATHER CONCERNS TO REMAIN MINIMAL FOR THE REST OF THE WEEK
WITH NON-CRITICAL WEATHER CONDITIONS EXPECTED. SOME WETTING RAINS
SHOULD OCCUR OVER AT LEAST PARTS OF THE AREA OVER THE NEXT COUPLE
DAYS AS A SURGE OF MONSOONAL MOISTURE PASSES OVER THE REGION AND
INCREASES PRECIPITATION.

&&

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

$$

UPDATE...SML
SHORT TERM...REC
LONG TERM...RE
AVIATION...HAMMER
FIRE WEATHER...RE







000
FXUS65 KCYS 200616
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
1216 AM MDT WED AUG 20 2014

.UPDATE...
ISSUED AT 958 PM MDT TUE AUG 19 2014

STRONG TO SEVERE THUNDERSTORM CHANCES HAVE ENDED FOR THE REST OF
TONIGHT. WILL MAINLY SEE SCATTERED SHOWERS AND ISOLATED
THUNDERSTORMS THE REST OF TONIGHT.

&&

.SHORT TERM...(TONIGHT THROUGH THURSDAY NIGHT)
ISSUED AT 250 PM MDT TUE AUG 19 2014

THE MAIN CONCERN WITH THIS FORECAST PACKAGE IS WHERE THE
CONVECTION WILL BREAK OUT THIS AFTERNOON AND HOW MUCH CONVECTION
WILL BREAK OUT AHEAD OF THE JET STREAK MOVING ACROSS THE ROCKIES
TONIGHT.

LATEST VISIBLE IMAGERY WAS SHOWING SOME ACCAS DEVELOPING ACROSS NORTHEAST
COLORADO NEAR THE SURFACE TROF. THIS AREA MAY END UP BEING THE
FIRST AREA TO FIRE UP THIS AFTERNOON. HOWEVER...IT MAY TRY TO
IGNITE JUST EAST OF THE LARAMIE AND FRONT RANGES AS WELL WHERE WE
HAVE HAD QUITE A BIT OF SUNSHINE. IN FACT...WE ARE STARTING TO SEE
A LITTLE BIT OF ACCAS OVERHEAD AND CONVECTION DEVELOPING ALONG THE
FRONT RANGE. MODELS ARE PROJECTING MIXED LAYER CAPES TO APPROACH 1500
J/KG THIS AFTERNOON WITH VERY LIMITED CAP. 0-6KM SHEAR VALUES
(~30KTS) MAY ALSO BE FAVORABLE FOR A FEW STRONG TO SEVERE STORMS.
AT THIS POINT...IT LOOKS THE HRRR IS STARTING TO BREAK OUT
CONVECTION JUST EAST OF CHEYENNE AFTER 21Z WITH THE BULK OF THIS
CONVECTION PUSHING GENERALLY EAST AT AROUND 20KTS. A FEW OF THESE
STORMS MAY HAVE THE POTENTIAL TO PRODUCING STRONG WINDS AND HAIL IN THE
PANHANDLE THIS AFTERNOON. LATEST SURFACE ANALYSIS WAS ALSO SHOWING
SOME WINDS BACKING TO THE SOUTHEAST IN THE PANHANDLE. WE WILL ALSO
NEED TO WATCH THAT AS THE AFTERNOON WEARS ON...ESPECIALLY IF THE
STORMS GET GOING IN THAT REGION.

ANOTHER CONCERN IS THE NAM IS SHOWING A 500MB JET STREAK MOVING
OUT OF NORTHEAST COLORADO EARLY THIS EVENING WHICH MAY HELP
ENHANCE THE SHEAR ACROSS THE PANHANDLE. IF CONVECTION IS ON GOING
IN THAT REGION AS THIS JET STREAK MOVES ACROSS WE MAY HAVE MORE OF
A SEVERE POTENTIAL. THEREFORE...IT WILL BE A MATTER OF TIMING ON
HOW THINGS COME TOGETHER LATE THIS AFTERNOON AND EVENING.

TONIGHT THE MODELS ARE SHOWING A FAIRLY STRONG UPPER LEVEL JET
MOVING THROUGH NORTHERN COLORADO AND LIFTING NORTHEAST INTO
NORTHEAST WYOMING BY DAYBREAK WHICH WILL HELP ENHANCE UPPER LEVEL
DIFFLUENCE. THE MODELS ARE EVEN IN FAIRLY GOOD AGREEMENT IN
SHOWING A MID LEVEL CIRCULATION WITH THIS JET STREAK. AS A
RESULT... WE WOULD NOT SURPRISED TO SEE A COMPLEX OF SHOWERS AND
THUNDERSTORMS DEVELOP ACROSS THE WESTERN HALF OF THE FORECAST AREA
OVERNIGHT ALONG WITH THE POTENTIAL FOR HEAVY RAINFALL DUE TO PRECIPITABLE
WATER VALUES AROUND 1 INCH. NOT EXPECTING MUCH IN THE WAY OF
FLOODING SINCE THIS COMPLEX SHOULD BE FAIRLY PROGRESSIVE. WE DID
BUMP UP POPS ACROSS THE NORTHERN HALF OF THE AREA TONIGHT TO
REFLECT THIS POTENTIAL.

WEDNESDAY-THURSDAY NIGHT:
THE MID LEVEL CIRCULATION IS PROGGED TO CONTINUE LIFTING NORTHEAST
WHICH WILL TAKE THE BULK OF THE CONVECTION NORTHEAST OF THE
FORECAST AREA BY MID MORNING. THIS WILL LEAVE A FAIRLY BROAD AREA OF
SUBSIDENCE IN THE MORNING IN THE WAKE OF THE CONVECTION...BUT WE
MAY MORE CONVECTION DEVELOP IN THE AFTERNOON ACROSS THE MOUNTAINS
AS UPSLOPE FLOW COMMENCES WITH LEFTOVER RESIDUAL MOISTURE.
OTHERWISE...THE REMAINDER OF THE AREA EAST OF THE LARAMIE RANGE
SHOULD REMAIN FAIRLY DRY WITH HIGHS GENERALLY IN THE 80S. THE
NEXT CHANCE OF SHOWERS AND THUNDERSTORMS IS PROGGED TO TAKE PLACE
ON THURSDAY AFTERNOON AS ANOTHER UPPER LEVEL WAVE LIFTS NORTHEAST
OUT OF COLORADO AND PUSHES THROUGH AREAS EAST OF THE LARAMIE RANGE
THURSDAY AFTERNOON INTO THURSDAY NIGHT.

.LONG TERM...(FRIDAY THROUGH TUESDAY)
ISSUED AT 250 PM MDT TUE AUG 19 2014

AN UPPER LOW AND ASSOCIATED TROUGH OVER THE PACIFIC NW FRIDAY WILL
MOVE SLOWLY EAST TOWARDS THE AREA FRIDAY THROUGH SATURDAY...
SWINGING BY THE AREA ON SUNDAY. THIS WILL COMBINE WITH AT LEAST
RESIDUAL MONSOONAL MOISTURE TO KEEP CHANCES FOR SHOWERS AND TSTMS
GOING OVER MOST AREAS THROUGH SATURDAY NIGHT. WILL CONTINUE TO
LEAN TOWARDS THE EC SOLUTION AS IT HAS BEEN FAIRLY CONSISTENT WITH
THIS FEATURE. WARM TEMPS WILL CONTINUE THROUGH SATURDAY THEN A
DECENT COOL FRONT WILL PASS ACROSS SAT NIGHT LEAVING A DRIER AND
MILD DAY FOR THE CWA SUNDAY. CONTINUED MILD ON MONDAY WITH THE CWA
ON THE SOUTHERN PORTION OF BROAD CYCLONIC UPPER FLOW THAT WILL BE
OVER THE NORTHERN PART OF THE COUNTRY. A SECOND UPPER SHORTWAVE
SHOULD PASS BY TUESDAY BRINGING A REINFORCING SHOT OF COOLER AIR
AND A CHANCE FOR SOME PRECIPITATION.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1215 AM MDT WED AUG 20 2014

SHOWERS WILL INCREASE FROM WEST TO EAST ACROSS THE AREA TONIGHT.
VFR CONDITIONS ARE EXPECTED FOR MOST TERMINALS WITH CIGS BETWEEN
5K AND 10K FEET AGL. BRIEF MVFR CIGS OR VSBYS COULD OCCUR WITH ANY
HEAVIER PRECIPITATION AFTER 06Z. ISOLATED SHOWERS OR WEAK TSTMS
COULD BE IN THE VICINITY OF MOST TERMINALS THROUGH MOST OF THE TAF
PERIOD. WINDS WILL GENERALLY BE BELOW 15 KTS...EXCEPT GUSTY AND
VARIABLE NEAR ANY SHOWERS.

&&

.FIRE WEATHER...
ISSUED AT 1056 AM MDT TUE AUG 19 2014

FIRE WEATHER CONCERNS TO REMAIN MINIMAL FOR THE REST OF THE WEEK
WITH NON-CRITICAL WEATHER CONDITIONS EXPECTED. SOME WETTING RAINS
SHOULD OCCUR OVER AT LEAST PARTS OF THE AREA OVER THE NEXT COUPLE
DAYS AS A SURGE OF MONSOONAL MOISTURE PASSES OVER THE REGION AND
INCREASES PRECIPITATION.

&&

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

$$

UPDATE...SML
SHORT TERM...REC
LONG TERM...RE
AVIATION...HAMMER
FIRE WEATHER...RE








000
FXUS65 KCYS 200357
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
957 PM MDT TUE AUG 19 2014

.UPDATE...
ISSUED AT 958 PM MDT TUE AUG 19 2014

STRONG TO SEVERE THUNDERSTORM CHANCES HAVE ENDED FOR THE REST OF
TONIGHT. WILL MAINLY SEE SCATTERED SHOWERS AND ISOLATED
THUNDERSTORMS THE REST OF TONIGHT.

&&

.SHORT TERM...(TONIGHT THROUGH THURSDAY NIGHT)
ISSUED AT 250 PM MDT TUE AUG 19 2014

THE MAIN CONCERN WITH THIS FORECAST PACKAGE IS WHERE THE
CONVECTION WILL BREAK OUT THIS AFTERNOON AND HOW MUCH CONVECTION
WILL BREAK OUT AHEAD OF THE JET STREAK MOVING ACROSS THE ROCKIES
TONIGHT.

LATEST VISIBLE IMAGERY WAS SHOWING SOME ACCAS DEVELOPING ACROSS NORTHEAST
COLORADO NEAR THE SURFACE TROF. THIS AREA MAY END UP BEING THE
FIRST AREA TO FIRE UP THIS AFTERNOON. HOWEVER...IT MAY TRY TO
IGNITE JUST EAST OF THE LARAMIE AND FRONT RANGES AS WELL WHERE WE
HAVE HAD QUITE A BIT OF SUNSHINE. IN FACT...WE ARE STARTING TO SEE
A LITTLE BIT OF ACCAS OVERHEAD AND CONVECTION DEVELOPING ALONG THE
FRONT RANGE. MODELS ARE PROJECTING MIXED LAYER CAPES TO APPROACH 1500
J/KG THIS AFTERNOON WITH VERY LIMITED CAP. 0-6KM SHEAR VALUES
(~30KTS) MAY ALSO BE FAVORABLE FOR A FEW STRONG TO SEVERE STORMS.
AT THIS POINT...IT LOOKS THE HRRR IS STARTING TO BREAK OUT
CONVECTION JUST EAST OF CHEYENNE AFTER 21Z WITH THE BULK OF THIS
CONVECTION PUSHING GENERALLY EAST AT AROUND 20KTS. A FEW OF THESE
STORMS MAY HAVE THE POTENTIAL TO PRODUCING STRONG WINDS AND HAIL IN THE
PANHANDLE THIS AFTERNOON. LATEST SURFACE ANALYSIS WAS ALSO SHOWING
SOME WINDS BACKING TO THE SOUTHEAST IN THE PANHANDLE. WE WILL ALSO
NEED TO WATCH THAT AS THE AFTERNOON WEARS ON...ESPECIALLY IF THE
STORMS GET GOING IN THAT REGION.

ANOTHER CONCERN IS THE NAM IS SHOWING A 500MB JET STREAK MOVING
OUT OF NORTHEAST COLORADO EARLY THIS EVENING WHICH MAY HELP
ENHANCE THE SHEAR ACROSS THE PANHANDLE. IF CONVECTION IS ON GOING
IN THAT REGION AS THIS JET STREAK MOVES ACROSS WE MAY HAVE MORE OF
A SEVERE POTENTIAL. THEREFORE...IT WILL BE A MATTER OF TIMING ON
HOW THINGS COME TOGETHER LATE THIS AFTERNOON AND EVENING.

TONIGHT THE MODELS ARE SHOWING A FAIRLY STRONG UPPER LEVEL JET
MOVING THROUGH NORTHERN COLORADO AND LIFTING NORTHEAST INTO
NORTHEAST WYOMING BY DAYBREAK WHICH WILL HELP ENHANCE UPPER LEVEL
DIFFLUENCE. THE MODELS ARE EVEN IN FAIRLY GOOD AGREEMENT IN
SHOWING A MID LEVEL CIRCULATION WITH THIS JET STREAK. AS A
RESULT... WE WOULD NOT SURPRISED TO SEE A COMPLEX OF SHOWERS AND
THUNDERSTORMS DEVELOP ACROSS THE WESTERN HALF OF THE FORECAST AREA
OVERNIGHT ALONG WITH THE POTENTIAL FOR HEAVY RAINFALL DUE TO PRECIPITABLE
WATER VALUES AROUND 1 INCH. NOT EXPECTING MUCH IN THE WAY OF
FLOODING SINCE THIS COMPLEX SHOULD BE FAIRLY PROGRESSIVE. WE DID
BUMP UP POPS ACROSS THE NORTHERN HALF OF THE AREA TONIGHT TO
REFLECT THIS POTENTIAL.

WEDNESDAY-THURSDAY NIGHT:
THE MID LEVEL CIRCULATION IS PROGGED TO CONTINUE LIFTING NORTHEAST
WHICH WILL TAKE THE BULK OF THE CONVECTION NORTHEAST OF THE
FORECAST AREA BY MID MORNING. THIS WILL LEAVE A FAIRLY BROAD AREA OF
SUBSIDENCE IN THE MORNING IN THE WAKE OF THE CONVECTION...BUT WE
MAY MORE CONVECTION DEVELOP IN THE AFTERNOON ACROSS THE MOUNTAINS
AS UPSLOPE FLOW COMMENCES WITH LEFTOVER RESIDUAL MOISTURE.
OTHERWISE...THE REMAINDER OF THE AREA EAST OF THE LARAMIE RANGE
SHOULD REMAIN FAIRLY DRY WITH HIGHS GENERALLY IN THE 80S. THE
NEXT CHANCE OF SHOWERS AND THUNDERSTORMS IS PROGGED TO TAKE PLACE
ON THURSDAY AFTERNOON AS ANOTHER UPPER LEVEL WAVE LIFTS NORTHEAST
OUT OF COLORADO AND PUSHES THROUGH AREAS EAST OF THE LARAMIE RANGE
THURSDAY AFTERNOON INTO THURSDAY NIGHT.

.LONG TERM...(FRIDAY THROUGH TUESDAY)
ISSUED AT 250 PM MDT TUE AUG 19 2014

AN UPPER LOW AND ASSOCIATED TROUGH OVER THE PACIFIC NW FRIDAY WILL
MOVE SLOWLY EAST TOWARDS THE AREA FRIDAY THROUGH SATURDAY...
SWINGING BY THE AREA ON SUNDAY. THIS WILL COMBINE WITH AT LEAST
RESIDUAL MONSOONAL MOISTURE TO KEEP CHANCES FOR SHOWERS AND TSTMS
GOING OVER MOST AREAS THROUGH SATURDAY NIGHT. WILL CONTINUE TO
LEAN TOWARDS THE EC SOLUTION AS IT HAS BEEN FAIRLY CONSISTENT WITH
THIS FEATURE. WARM TEMPS WILL CONTINUE THROUGH SATURDAY THEN A
DECENT COOL FRONT WILL PASS ACROSS SAT NIGHT LEAVING A DRIER AND
MILD DAY FOR THE CWA SUNDAY. CONTINUED MILD ON MONDAY WITH THE CWA
ON THE SOUTHERN PORTION OF BROAD CYCLONIC UPPER FLOW THAT WILL BE
OVER THE NORTHERN PART OF THE COUNTRY. A SECOND UPPER SHORTWAVE
SHOULD PASS BY TUESDAY BRINGING A REINFORCING SHOT OF COOLER AIR
AND A CHANCE FOR SOME PRECIPITATION.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY AFTERNOON)
ISSUED AT 545 PM MDT TUE AUG 19 2014

ISOLATED TO WIDELY SCATTERED SHOWERS AND TSTMS SHOULD CONTINUE
THROUGH MID TO LATE EVENING ACROSS MUCH OF SOUTHEAST WY AND THE
WESTERN NE PANHANDLE. THE MAIN HAZARD TO AVIATION INTERESTS WILL
BE GUSTY AND ERRATIC SURFACE WINDS WITH GUSTS TO 40 KTS ASSOCIATED
WITH THE STRONGEST STORMS. MVFR VSBYS COULD ALSO OCCUR WITH HEAVY
PRECIPITATION CORES. MENTIONED VCSH OR VCTS IN THE LATEST ISSUANCE
EXCEPT FOR THOSE AREAS SUCH AS AIA THAT ARE MORE LIKELY TO SEE ANY
SIGNIFICANT WEATHER IN THE NEXT FEW HOURS. INCLUDED A TEMPO GROUP
THERE. CIGS SHOULD GENERALLY BE VFR...AT OR AROUND 10K FEET FOR
MOST SITES. SHOWERS WILL INCREASE AGAIN FROM WEST TO EAST FROM
LATE TONIGHT INTO EARLY WED.


&&

.FIRE WEATHER...
ISSUED AT 1056 AM MDT TUE AUG 19 2014

FIRE WEATHER CONCERNS TO REMAIN MINIMAL FOR THE REST OF THE WEEK
WITH NON-CRITICAL WEATHER CONDITIONS EXPECTED. SOME WETTING RAINS
SHOULD OCCUR OVER AT LEAST PARTS OF THE AREA OVER THE NEXT COUPLE
DAYS AS A SURGE OF MONSOONAL MOISTURE PASSES OVER THE REGION AND
INCREASES PRECIPITATION.

&&

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

$$

UPDATE...SML
SHORT TERM...REC
LONG TERM...RE
AVIATION...HAMMER
FIRE WEATHER...RE








000
FXUS65 KCYS 200357
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
957 PM MDT TUE AUG 19 2014

.UPDATE...
ISSUED AT 958 PM MDT TUE AUG 19 2014

STRONG TO SEVERE THUNDERSTORM CHANCES HAVE ENDED FOR THE REST OF
TONIGHT. WILL MAINLY SEE SCATTERED SHOWERS AND ISOLATED
THUNDERSTORMS THE REST OF TONIGHT.

&&

.SHORT TERM...(TONIGHT THROUGH THURSDAY NIGHT)
ISSUED AT 250 PM MDT TUE AUG 19 2014

THE MAIN CONCERN WITH THIS FORECAST PACKAGE IS WHERE THE
CONVECTION WILL BREAK OUT THIS AFTERNOON AND HOW MUCH CONVECTION
WILL BREAK OUT AHEAD OF THE JET STREAK MOVING ACROSS THE ROCKIES
TONIGHT.

LATEST VISIBLE IMAGERY WAS SHOWING SOME ACCAS DEVELOPING ACROSS NORTHEAST
COLORADO NEAR THE SURFACE TROF. THIS AREA MAY END UP BEING THE
FIRST AREA TO FIRE UP THIS AFTERNOON. HOWEVER...IT MAY TRY TO
IGNITE JUST EAST OF THE LARAMIE AND FRONT RANGES AS WELL WHERE WE
HAVE HAD QUITE A BIT OF SUNSHINE. IN FACT...WE ARE STARTING TO SEE
A LITTLE BIT OF ACCAS OVERHEAD AND CONVECTION DEVELOPING ALONG THE
FRONT RANGE. MODELS ARE PROJECTING MIXED LAYER CAPES TO APPROACH 1500
J/KG THIS AFTERNOON WITH VERY LIMITED CAP. 0-6KM SHEAR VALUES
(~30KTS) MAY ALSO BE FAVORABLE FOR A FEW STRONG TO SEVERE STORMS.
AT THIS POINT...IT LOOKS THE HRRR IS STARTING TO BREAK OUT
CONVECTION JUST EAST OF CHEYENNE AFTER 21Z WITH THE BULK OF THIS
CONVECTION PUSHING GENERALLY EAST AT AROUND 20KTS. A FEW OF THESE
STORMS MAY HAVE THE POTENTIAL TO PRODUCING STRONG WINDS AND HAIL IN THE
PANHANDLE THIS AFTERNOON. LATEST SURFACE ANALYSIS WAS ALSO SHOWING
SOME WINDS BACKING TO THE SOUTHEAST IN THE PANHANDLE. WE WILL ALSO
NEED TO WATCH THAT AS THE AFTERNOON WEARS ON...ESPECIALLY IF THE
STORMS GET GOING IN THAT REGION.

ANOTHER CONCERN IS THE NAM IS SHOWING A 500MB JET STREAK MOVING
OUT OF NORTHEAST COLORADO EARLY THIS EVENING WHICH MAY HELP
ENHANCE THE SHEAR ACROSS THE PANHANDLE. IF CONVECTION IS ON GOING
IN THAT REGION AS THIS JET STREAK MOVES ACROSS WE MAY HAVE MORE OF
A SEVERE POTENTIAL. THEREFORE...IT WILL BE A MATTER OF TIMING ON
HOW THINGS COME TOGETHER LATE THIS AFTERNOON AND EVENING.

TONIGHT THE MODELS ARE SHOWING A FAIRLY STRONG UPPER LEVEL JET
MOVING THROUGH NORTHERN COLORADO AND LIFTING NORTHEAST INTO
NORTHEAST WYOMING BY DAYBREAK WHICH WILL HELP ENHANCE UPPER LEVEL
DIFFLUENCE. THE MODELS ARE EVEN IN FAIRLY GOOD AGREEMENT IN
SHOWING A MID LEVEL CIRCULATION WITH THIS JET STREAK. AS A
RESULT... WE WOULD NOT SURPRISED TO SEE A COMPLEX OF SHOWERS AND
THUNDERSTORMS DEVELOP ACROSS THE WESTERN HALF OF THE FORECAST AREA
OVERNIGHT ALONG WITH THE POTENTIAL FOR HEAVY RAINFALL DUE TO PRECIPITABLE
WATER VALUES AROUND 1 INCH. NOT EXPECTING MUCH IN THE WAY OF
FLOODING SINCE THIS COMPLEX SHOULD BE FAIRLY PROGRESSIVE. WE DID
BUMP UP POPS ACROSS THE NORTHERN HALF OF THE AREA TONIGHT TO
REFLECT THIS POTENTIAL.

WEDNESDAY-THURSDAY NIGHT:
THE MID LEVEL CIRCULATION IS PROGGED TO CONTINUE LIFTING NORTHEAST
WHICH WILL TAKE THE BULK OF THE CONVECTION NORTHEAST OF THE
FORECAST AREA BY MID MORNING. THIS WILL LEAVE A FAIRLY BROAD AREA OF
SUBSIDENCE IN THE MORNING IN THE WAKE OF THE CONVECTION...BUT WE
MAY MORE CONVECTION DEVELOP IN THE AFTERNOON ACROSS THE MOUNTAINS
AS UPSLOPE FLOW COMMENCES WITH LEFTOVER RESIDUAL MOISTURE.
OTHERWISE...THE REMAINDER OF THE AREA EAST OF THE LARAMIE RANGE
SHOULD REMAIN FAIRLY DRY WITH HIGHS GENERALLY IN THE 80S. THE
NEXT CHANCE OF SHOWERS AND THUNDERSTORMS IS PROGGED TO TAKE PLACE
ON THURSDAY AFTERNOON AS ANOTHER UPPER LEVEL WAVE LIFTS NORTHEAST
OUT OF COLORADO AND PUSHES THROUGH AREAS EAST OF THE LARAMIE RANGE
THURSDAY AFTERNOON INTO THURSDAY NIGHT.

.LONG TERM...(FRIDAY THROUGH TUESDAY)
ISSUED AT 250 PM MDT TUE AUG 19 2014

AN UPPER LOW AND ASSOCIATED TROUGH OVER THE PACIFIC NW FRIDAY WILL
MOVE SLOWLY EAST TOWARDS THE AREA FRIDAY THROUGH SATURDAY...
SWINGING BY THE AREA ON SUNDAY. THIS WILL COMBINE WITH AT LEAST
RESIDUAL MONSOONAL MOISTURE TO KEEP CHANCES FOR SHOWERS AND TSTMS
GOING OVER MOST AREAS THROUGH SATURDAY NIGHT. WILL CONTINUE TO
LEAN TOWARDS THE EC SOLUTION AS IT HAS BEEN FAIRLY CONSISTENT WITH
THIS FEATURE. WARM TEMPS WILL CONTINUE THROUGH SATURDAY THEN A
DECENT COOL FRONT WILL PASS ACROSS SAT NIGHT LEAVING A DRIER AND
MILD DAY FOR THE CWA SUNDAY. CONTINUED MILD ON MONDAY WITH THE CWA
ON THE SOUTHERN PORTION OF BROAD CYCLONIC UPPER FLOW THAT WILL BE
OVER THE NORTHERN PART OF THE COUNTRY. A SECOND UPPER SHORTWAVE
SHOULD PASS BY TUESDAY BRINGING A REINFORCING SHOT OF COOLER AIR
AND A CHANCE FOR SOME PRECIPITATION.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY AFTERNOON)
ISSUED AT 545 PM MDT TUE AUG 19 2014

ISOLATED TO WIDELY SCATTERED SHOWERS AND TSTMS SHOULD CONTINUE
THROUGH MID TO LATE EVENING ACROSS MUCH OF SOUTHEAST WY AND THE
WESTERN NE PANHANDLE. THE MAIN HAZARD TO AVIATION INTERESTS WILL
BE GUSTY AND ERRATIC SURFACE WINDS WITH GUSTS TO 40 KTS ASSOCIATED
WITH THE STRONGEST STORMS. MVFR VSBYS COULD ALSO OCCUR WITH HEAVY
PRECIPITATION CORES. MENTIONED VCSH OR VCTS IN THE LATEST ISSUANCE
EXCEPT FOR THOSE AREAS SUCH AS AIA THAT ARE MORE LIKELY TO SEE ANY
SIGNIFICANT WEATHER IN THE NEXT FEW HOURS. INCLUDED A TEMPO GROUP
THERE. CIGS SHOULD GENERALLY BE VFR...AT OR AROUND 10K FEET FOR
MOST SITES. SHOWERS WILL INCREASE AGAIN FROM WEST TO EAST FROM
LATE TONIGHT INTO EARLY WED.


&&

.FIRE WEATHER...
ISSUED AT 1056 AM MDT TUE AUG 19 2014

FIRE WEATHER CONCERNS TO REMAIN MINIMAL FOR THE REST OF THE WEEK
WITH NON-CRITICAL WEATHER CONDITIONS EXPECTED. SOME WETTING RAINS
SHOULD OCCUR OVER AT LEAST PARTS OF THE AREA OVER THE NEXT COUPLE
DAYS AS A SURGE OF MONSOONAL MOISTURE PASSES OVER THE REGION AND
INCREASES PRECIPITATION.

&&

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

$$

UPDATE...SML
SHORT TERM...REC
LONG TERM...RE
AVIATION...HAMMER
FIRE WEATHER...RE







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