Area Forecast Discussion
Issued by NWS Cheyenne, WY

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FXUS65 KCYS 302030
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
230 PM MDT TUE JUN 30 2015

.SHORT TERM...(THIS EVENING THROUGH THURSDAY NIGHT)
ISSUED AT 230 PM MDT TUE JUN 30 2015

SURFACE ANALYSIS SHOWING A FRONTAL BOUNDARY OVER WESTERN SOUTH
DAKOTA...EXTENDING INTO EXTREME NORTHEASTERN WYOMING EARLY THIS
AFTERNOON. RADAR SHOWING SOME SHOWERS DEVELOPING OVER THE NORTH
LARAMIE RANGE THIS AFTERNOON. LAPRELLE CREEK AND WINDY PEAK
SNOTELS SHOWING SOME PRETTY GOOD RAINFALL AMOUNTS IN THE NORTH
LARAMIE RANGE. BUT OUTSIDE THIS AREA...IT STILL LOOKS LIKE ECHOES
ARE ELEVATED. 1PM HUMIDITY AT CHEYENNE AT 19 PERCENT...DOUGLAS AT
24 PERCENT...LARAMIE 21 PERCENT...SO THESE ECHOES ARE GOING TO
TAKE QUITE A WHILE TO REACH THE GROUND. SO FOR THIS
AFTERNOON...THINK MOST PLACES WILL REMAIN DRY UNTIL THE LATE
AFTERNOON HOURS. LATEST SPC MESOANALYSIS SHOWING AROUND 500J/KG
CAPE ACROSS SOUTHERN WYOMING. NIOBRARA COUNTY AND THE PANHANDLE
JUST LOST THEIR CAP OUT THAT WAY WITH CAPE VALUES AROUND 1000J/KG.
JUST NORTH OF THE PANHANDLE NEAR THE FRONT...SURFACE BASED CAPES
OF 2500 TO 3500 J/KG EXISTS. LOOKS LIKE THE SLIGHT RISK AREA IS
STILL HOLDING GOOD UP THAT WAY.

LATEST HRRR SIMULATED RADAR SHOWS INCREASING AREA OF SHOWERS AND
THUNDERSTORMS MOVING SOUTHEAST LATE THIS AFTERNOON THAT MOVE INTO
THE PANHANDLE THROUGH THE EARLY EVENING HOURS. CONTINUE THE CHANCE
POP FORECAST FOR THIS AFTERNOON WITH SMALL HAIL AND GUSTY WINDS.
COULD SEE A COUPLE SEVERE STORMS MOVE INTO THE NORTHERN PANHANDLE
FROM WESTERN SOUTH DAKOTA/NORTHEASTERN WYOMING. OVERALL
THOUGH...DO THINK CHANCES WILL BE LOW.

BETTER CHANCES APPEAR FOR WEDNESDAY AFTERNOON FOR LOCATIONS ALONG
THE INTERSTATE 80 CORRIDOR AS THE FRONT STALLS ALONG THE LARAMIE
RANGE. THIS IS DEPICTED ON THE ECMWF. GFS HAS FRONT FURTHER EAST
IN NEBRASKA. DUE TO THE DIFFERENCES...DI NOT CHANGE POPS TOO MUCH
FOR WEDNESDAY WITH CHANCE POPS.

DID INCREASE POPS FOR THE PANHANDLE WEDNESDAY NIGHT INTO THURSDAY
MORNING. ECMWF SHOWING FRONT LIFTING ENE INTO WESTERN NEBRASKA.
NAM SOUNDINGS FOR THE PANHANDLE SHOWING PWATS ALMOST TO 1.3 INCHES
WITH LONG/SKINNY CAPE PROFILES. GOOD NEWS IS FORECAST STORM
MOTIONS ARE FAIRLY HIGH...SO DO THINK WE ARE OK FOR POSSIBLE HEAVY
RAIN THREAT DURING THAT TIME.

.LONG TERM...(FRIDAY THROUGH TUESDAY)
ISSUED AT 230 PM MDT TUE JUN 30 2015

ELONGATED UPPER RIDGE WILL HOLD ACROSS THE SW CONUS THIS PERIOD
WITH A GENERALLY NWLY FLOW ALOFT OVER THE CWA ON THE NORTHEAST
PERIPHERY OF THE UPPER HIGH. MAINLY DRY CONDITIONS ARE EXPECTED
FRIDAY THROUGH THE WEEKEND THOUGH BY SUNDAY INTO EARLY NEXT WEEK
CONVECTION SHOULD INCREASE AS BETTER MOISTURE ADVECTS INTO THE
REGION FROM THE SW. A COOL FRONT IS EXPECTED TO PASS ACROSS SUNDAY
BRINGING A MODEST COOL DOWN INTO MONDAY BEFORE TEMPS REBOUND
TUESDAY. POST FRONTAL UPSLOPE PATTERN SHOULD HELP PCPN CHANCES
MONDAY WITH CHANCES FOR SHOWERS AND TSTMS CONTINUING TUESDAY.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1115 AM MDT TUE JUN 30 2015

VFR CONDITIONS WILL PREVAIL...EXCEPT FOR SOME BRIEF MVFR
VISIBILITIES IN WIDELY SCATTERED AFTERNOON/EVENING SHOWERS/TSTORMS
MAINLY AFFECTING SE WY TERMINALS THIS AFTERNOON INTO EARLY EVENING.

&&

.FIRE WEATHER...
ISSUED AT 230 PM MDT TUE JUN 30 2015

NORTH LARAMIE RANGE SEEING WETTING RAINS EARLY THIS AFTERNOON WITH
SHOWERS AND THUNDERSTORMS MOVING SOUTHEAST ALONG A FRONTAL
BOUNDARY MOVING INTO THE AREA FROM THE NORTH. FOR AREAS EAST OF
THE LARAMIE RANGE...IT WILL TAKE SOME TIME FOR SHOWERS TO REACH
THE GROUND AS AFTERNOON HUMIDITIES QUITE LOW. EVENTUALLY
THOUGH...MUCH OF SOUTHERN WYOMING AND SOUTHERN NEBRASKA PANHANDLE
SHOULD SEE WETTING RAINS LATE AFTERNOON THROUGH EARLY EVENING.
BETTER CHANCES WEDNESDAY AFTERNOON AS THE FRONT STALLS ALONG THE
EAST SLOPES OF THE LARAMIE RANGE. NO FIRE WEATHER CONCERNS THROUGH
THE WEEK AS AFTERNOON HUMIDITIES SHOULD REMAIN ABOVE CRITICAL
LEVELS AND FUELS ARE GREEN.

&&

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

$$

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


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