Area Forecast Discussion
Issued by NWS Cheyenne, WY

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000
FXUS65 KCYS 070548
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
1138 PM MDT SUN JUL 6 2014

.UPDATE...
ISSUED AT 600 PM MDT SUN JUL 6 2014

VISIBLE SATELLITE IMAGERY LOOP SHOWING A STABILIZING OUTFLOW
BOUNDARY FROM EARLIER NORTHERN COLORADO THUNDERSTORMS MOVING
NORTH AND WEST ACROSS WESTERN LARAMIE AND SOUTHERN ALBANY
COUNTIES...AND WITH VISIBLE SATELLITE IMAGERY AND WSR-88D
REFLECTIVITIES FROM RADARS AT CHEYENNE...DENVER...GRAND
JUNCTION...RIVERTON...RAPID CITY AND NORTH PLATTE SHOWING NEAR
ZERO CONVECTIVE DEVELOPMENT OVER OUR COUNTIES...HAVE UPDATED OUR
GRIDDED FORECASTS FOR THE EVENING AS WELL AS MADE ADJUSTMENTS TO
TEMPERATURES AND DEWPOINTS FOR THIS EVENING BASED ON TRENDS.
CUMULUS AND TOWERING CUMULUS LOOKING RATHER INNOCUOUS VISUALLY
OUTSIDE AND ALSO ON VISIBLE SATELLITE IMAGERY...THUS QUITE
MINIMAL THUNDERSTORM INITIATION CHANCES THE REST OF THE NIGHT.

64/RUBIN

&&

.SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT)
ISSUED AT 255 PM MDT SUN JUL 6 2014

CONVECTION DOWN IN COLORADO EARLY THIS AFTERNOON THOUGH SOME
DEVELOPING VERY CLOSE TO THE WY BORDER SW OF CHEYENNE. MAY STILL
SEE A COUPLE CELLS OVER THE SOUTH LARAMIE RANGE THIS AFTERNOON BUT
ANY THAT DO FORM WILL MOVE SE INTO COLORADO. DRY ELSEWHERE
TONIGHT.

UPPER FLOW OVER THE REGION WILL BECOME MORE NWLY LATE TONIGHT AND
MONDAY AS SHORTWAVE ENERGY MOVES ACROSS THE NORTHERN PLAINS. THIS
WILL ALLOW FOR A COOL FRONT TO DROP SOUTH ACROSS THE CWA LATE
MONDAY MORNING AND AFTERNOON BRINGING A LITTLE COOLER
TEMPERATURES. MODEST UPSLOPE FLOW MAY ALLOW FOR A FEW SHOWERS AND
TSTMS TO DEVELOP IN THE AFTERNOON. A FEW STRONG STORMS POSSIBLE
THOUGH BETTER INSTABILITY LOOKS TO BE SUPPRESSED TO THE SOUTH
ALONG THE FRONT.

MAINLY DRY MONDAY NIGHT AND TUESDAY AS A SFC HIGH SETTLES DOWN THE
PLAINS WITH MILD TO WARM TEMPERATURES TUESDAY.

.LONG TERM...(WEDNESDAY THROUGH SUNDAY)
ISSUED AT 255 PM MDT SUN JUL 6 2014

GFS AND ECMWF IN PRETTY GOOD AGREEMENT TAKING THE UPPER RIDGE OVER
THE 4 CORNERS REGION AND SLOWLY SHIFTING IT EAST INTO WEST TEXAS
AND OKLAHOMA BY FRIDAY...BRINGING THE SOUTHERN EDGE OF THE
STRONGER NORTHWESTERLY MIDLEVEL FLOW CLOSER TO OUR AREA IN THE
MIDWEEK TIMEFRAME. EXPECT TO SEE A BIT OF AN INCREASE IN PASSING
SHORTWAVE ENERGY EACH DAY AND HAVE KEPT DIURNAL POPS GOING
WEDNESDAY THROUGH THURSDAY WITH A BIT OF A WARMUP ON THURSDAY WHEN
TEMPS SHOULD GET UP INTO THE MID/UPPER 90S IN THE LOWER ELEVATIONS
BELOW 5000 FT MSL WITH HIGHER ELEVATIONS IN THE 80S EXCEPT ABOVE
9000 FT WHERE UPPER 60S TO LOWER 70S ARE EXPECTED. BY LATE IN THE
WEEK...THE GFS CONTINUES WITH A BROAD UPPER RIDGE OVER THE
SOUTHERN PLAINS WITH A SOUTHWESTERLY EARLY MONSOONAL FLOW
ADVERTISED BRINGING MOISTURE UP FROM THE EASTERN PACIFIC INTO OUR
AREA. PREVIOUS RUN OF THE ECMWF ALSO GAVE STRONG INDICATIONS OF A
MONSOONAL FLOW PATTERN LATE IN THE WEEK BUT THE LATEST 12Z RUN OF
THE ECMWF BUILDS ANOTHER RIDGE OUT OVER THE DESERT SOUTHWEST AND
TO A LESSER DEGREE NOW BRINGS MOISTURE IN ACROSS OUR AREA. GIVEN
THE OVERALL TRENDS OF THE PAST SEVERAL MODEL RUNS...BROUGHT POPS
UP A BIT FOR THE FRIDAY TO SATURDAY TIMEFRAME WITH THUNDERSTORMS
BEING MOST NUMEROUS IN THE AFTERNOON AND EVENING HOURS FRIDAY AND
SATURDAY.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH MONDAY AFTERNOON)

VFR CONDITIONS EXPECTED THROUGH TONIGHT AND INTO MONDAY MORNING. A
FEW MODELS CONTINUE TO HINT AT SOME LATE NIGHT CONVECTION MOVING
SOUTHEAST ACROSS WESTERN NEBRASKA AFTER 09Z...BUT CONFIDENCE IN THAT
IS FAIRLY LOW SO DID NOT INCLUDE IN THE TAF PACKAGE. LIGHT WINDS ARE
EXPECTED TONIGHT AS WELL WITH WINDS INCREASING OUT OF THE NORTH
THROUGH MONDAY. ISOLATED THUNDERSTORMS ARE POSSIBLE ALONG AND EAST
OF THE LARAMIE RANGE BY LATE MONDAY AFTERNOON.

&&

.FIRE WEATHER...
ISSUED AT 255 PM MDT SUN JUL 6 2014

CONCERNS TO REMAIN GENERALLY LOW THIS WEEK WITH CONDITIONS MAINLY
NON-CRITICAL. MIN AFTERNOON HUMIDITIES WILL FALL TO NEAR 10
PERCENT OVER WESTERN DISTRICTS EARLY IN THE WEEK THEN MONSOONAL
MOISTURE SHOULD INCREASE AND RAISE RHS SOME BY THE MID TO LATE
PART OF THE WEEK.

&&

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

$$

UPDATE...RUBIN
SHORT TERM...RE
LONG TERM...GARMON
AVIATION...TJT
FIRE WEATHER...RE









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