Area Forecast Discussion
Issued by NWS Cheyenne, WY

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FXUS65 KCYS 250321
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
921 PM MDT FRI JUL 24 2015

.UPDATE...
ISSUED AT 611 PM MDT FRI JUL 24 2015

RADAR AND SATELLITE PICS EARLY THIS EVENING SHOW A FEW VIGOROUS
SHOWERS ALONG A BOUNDARY EXTENDING FROM FAR NORTHWEST LARAMIE
COUNTY EAST INTO THE CENTRAL NEBRASKA PANHANDLE. A FEW SHOWERS ARE
ALSO DEVELOPING ALONG THE PINE RIDGE FROM CENTRAL NIOBRARA COUNTY
INTO NORTHERN SIOUX AND DAWES COUNTIES. WITH SBCAPES ANALYZED AT
GREATER THAN 1000 J/KG IN THESE AREAS...WOULDN`T BE SURPRISED IF
A FEW ISOLATED T-STORMS DEVELOPED FROM THIS ACTIVITY. MIDLEVEL
WINDS ARE PUSHING CONVECTION TO THE EAST-NORTHEAST...SO UPDATED
THE GRIDS TO REFLECT CURRENT ACTIVITY AND DOWNSTREAM TRAJECTORIES.

&&

.SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT)
ISSUED AT 239 PM MDT FRI JUL 24 2015

FORECAST CHALLENGES DEAL WITH TEMPERATURES AND FIRE WEATHER
CONCERNS THROUGH MONDAY.

CURRENTLY...LATEST WATER VAPOR IMAGERY SHOWING DRY SLOT PRETTY
MUCH RIGHT OVER THE CHEYENNE CWFA THIS AFTERNOON. MONSOONAL
MOISTURE TO THE SOUTH NOT MAKING ANY PROGRESS NORTH THIS AFTERNOON
AND REMAINS OVER THE COLORADO ROCKIES. LATEST RADAR SHOWING
SHOWERS AND THUNDERSTORMS IN THIS MOISTURE...BUT FOR SOUTHEAST
WYOMING...RADAR REMAINS PPINE. HAVE A STALLED OUT BOUNDARY ALONG
THE LARAMIE RANGE THAT SEPARATE VERY DRY AIR WEST AND DEWPOINTS IN
THE UPPER 50S TO LOW 60S EAST OUT INTO THE PANHANDLE.

DO NOT THINK WE WILL SEE MUCH FROM THE MOISTURE TO THE SOUTH
TODAY/THIS EVENING. LATEST HRRR HOURLY RADAR MOSAIC SHOWS SOME
ISOLATED SHOWERS DEVELOPING HERE NEAR CHEYENNE THAT DRIFT OUT INTO
THE PANHANDLE. HAS BEEN SHOWING THIS ALL MORNING...BUT SO
FAR...NOTHING HAS HAPPENED. SO CONFIDENCE NOT ALL THAT HIGH THAT
THIS SOLUTION WILL HAPPEN. CONTINUED A PERSISTENCE FORECAST FOR
THIS AFTERNOON AND EVENING.

LOOKING AT A PRETTY WARM DAY SATURDAY AS 700MB TEMPERATURES CLIMB
TO +18C ACROSS THE WYOMING/COLORADO BORDER. LIKELY OUR WARMEST DAY
OF THE YEAR. DID GO HIGHER THAN MOST GUIDANCE ON TEMPERATURES FOR
SATURDAY AFTERNOON.

VERY SIMILAR CONDITIONS SUNDAY...WITH INCREASING 700MB WINDS OUT
WEST. BY 00Z MONDAY GFS SHOWING 700MB WINDS OUT WEST AT 20-25KTS.
BY SUNDAY EVENING...THEY INCREASE TO 25 TO 30 KTS AND THEN BY
MONDAY MORNING...30 TO 35KTS. DID GO HIGHER ON OVERNIGHT LOWS
SUNDAY NIGHT AS ATMOSPHERE WOULD STAY WELL MIXED WITH POOR
HUMIDITY RECOVERIES. THIS WILL SET THE STAGE FOR A WIDESPREAD
CRITICAL FIRE WEATHER DAY MONDAY.

.LONG TERM...(MONDAY THROUGH FRIDAY)
ISSUED AT 239 PM MDT FRI JUL 24 2015

ANOTHER QUITE WARM DAY ACROSS THE CWA MONDAY AHEAD OF A POTENT
UPPER TROF THAT WILL BE MOVING INTO THE NRN ROCKYS. THIS WILL
BRING A RATHER WINDY DAY TO THE WIND-FAVORED AREAS OF SE WYOMING
WITH GUSTS OVER 40 MPH MAKING FOR SOME FIRE WEATHER CONCERNS. AS
THE UPPER TROF EDGES EASTWARD INTO THE NORTHERN PLAINS MONDAY
NIGHT A COLD FRONT WILL MOVE ACROSS THE CWA LEAVING DRY AND MILDER
WEATHER IN ITS WAKE FOR TUESDAY AND WEDNESDAY WITH MAX TEMPS AT OR
A LITTLE BELOW SEASONAL AVERAGES. AFTER THAT THE UPPER FLOW TURNS
GRADUALLY NORTHWESTERLY OVER THE CWA FOR THURSDAY AND FRIDAY
KEEPING A MAINLY DRY PATTERN IN PLACE WITH A GRADUAL WARMUP IN
TEMPS. MONSOONAL FLOW APPEARS IT WILL REMAIN CUT OFF MUCH OF NEXT
WEEK BUT SOME INDICATION IT WILL RETURN NEXT WEEKEND.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 919 PM MDT FRI JUL 24 2015

VFR. THROUGH 12Z...MOSTLY CLEAR SKIES NORTH OF A LARAMIE TO
TORRINGTON LINE...SCATTERED TO BROKEN CLOUDS AT OR ABOVE 10000
FEET AGL SOUTH OF THIS LINE.

AFTER 12Z...SCATTERED TO BROKEN CLOUDS AT OR ABOVE 10000 FEET AGL.
WINDS GUSTING 20 TO 30 KNOTS AFTER DAYBREAK ON SATURDAY...THEN
DECREASING EARLY SATURDAY EVENING.

&&

.FIRE WEATHER...
ISSUED AT 239 PM MDT FRI JUL 24 2015

WARM...DRY AND GUSTY EACH AFTERNOON THROUGH THE WEEKEND FOR AREAS
WEST OF THE LARAMIE RANGE AS HIGH PRESSURE DOMINATES THE WEATHER
OUT WEST. EAST OF THE LARAMIE RANGE...A STALLED FRONTAL BOUNDARY
WILL KEEP WINDS EASTERLY THIS AFTERNOON ACROSS THE PANHANDLE AS
WELL AS CONVERSE/NIOBRARA COUNTIES IN EAST CENTRAL WYOMING. WARM
TEMPERATURES AND LOW HUMIDITIES WILL CONTINUE THROUGH SUNDAY WITH
NEAR CRITICAL FIRE WEATHER CONDITIONS ALONG AND WEST OF THE
LARAMIE RANGE. GUIDANCE STILL SHOWS AN UNUSUALLY STRONG LOW
PRESSURE SYSTEM MOVING INTO WESTERN MONTANA SUNDAY NIGHT INTO
MONDAY. WE ARE STILL LOOKING AT A WIDESPREAD STRONG WIND EVENT
MONDAY. POOR OVERNIGHT HUMIDITY RECOVERIES SUNDAY NIGHT/MONDAY
MORNING WILL START HUMIDITIES OFF LOW MONDAY MORNING. AS THE WINDS
INCREASE...WE COULD SEE WIDESPREAD CRITICAL FIRE WEATHER
CONDITIONS AS EARLY AS 9AM MONDAY...PERSISTING THROUGH SUNSET.

&&

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

$$

UPDATE...RJM
SHORT TERM...GCC
LONG TERM...RE
AVIATION...RUBIN
FIRE WEATHER...GCC



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