Area Forecast Discussion
Issued by NWS Cheyenne, WY

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FXUS65 KCYS 281702
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
1102 AM MDT TUE OCT 28 2014

.UPDATE...
ISSUED AT 1053 AM MDT TUE OCT 28 2014

THIS MORNING/S WATER VAPOR IMAGERY SHOWED A UPPER RIDGE AXIS FROM
THE GREAT BASIN INTO EASTERN BRITISH COLUMBIA CANADA. A DRY /PWAT
0.15-0.25"/ NORTHWEST FLOW ALOFT DOMINATED THE CWA. VISIBLE IMAGERY
REVEALED SOME CIRRUS SPREADING EAST ACROSS WEST AND CENTRAL WYOMING.
SKIES WILL BE SUNNY TO MOSTLY SUNNY FOR THE REMAINDER OF THE DAY.
FORECAST REGIONAL SOUNDING DATA PROGS SLIGHTLY WARMER TEMPERATURES
COMPARED TO YESTERDAY WITH HIGHS IN THE 50S FOR THE PLAINS...WITH
30S AND 40S ALONG AND WEST OF THE LARAMIE RANGE. WEST TO NORTHWEST
SURFACE WINDS WILL BE GUSTY ALONG AND WEST OF THE LARAMIE RANGE...BUT
LIGHTER ELSEWHERE.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 236 AM MDT TUE OCT 28 2014

THE MAIN CONCERN WITH THIS FORECAST PACKAGE WILL BE THE TIMING OF
WHEN THE CIRRUS STRATUS WILL ERODE...AND ITS IMPACT ON
TEMPERATURES.

TODAY:
LATEST IR LOOP WAS SHOWING THE OROGRAPHICALLY INDUCED CIRRUS
STRATUS CONTINUING TO IMPACT AREAS EAST OF THE LARAMIE RANGE DUE
TO NORTHWEST FLOW AT SPEEDS OF 40 TO 50KTS ABOVE 15KFT. THESE WIND
SPEEDS ARE PROGGED TO INCREASE TO 50 TO 60KTS THIS MORNING. THIS
MAY ALLOW FOR SOME OF THESE CLOUDS TO SPREAD FURTHER EAST INTO THE
SOUTHERN NEBRASKA PANHANDLE BY MID MORNING. LATEST WATER VAPOR
LOOP WAS SHOWING SOME DRIER AIR TRYING TO PUSH INTO WESTERN
WYOMING. THIS DRIER AIR SHOULD MOVE INTO OUR FORECAST AREA BY MID
MORNING AND CAUSE THE CIRRUS TO GRADUALLY ERODE BY MIDDAY.
TEMPERATURES WILL ALSO BE SLOW TO CLIMB THIS MORNING...BUT THE
EROSION OF THE CIRRUS SHOULD ALLOW LARAMIE TO CLIMB TO THE UPPER
40S TO NEAR 50 BY MID AFTERNOON AND CHEYENNE INTO THE MID 50S.
OTHERWISE...DOWNSLOPE FLOW WILL IMPACT THE REGION...WITH
TEMPERATURES WARMING A FEW DEGREES MORE THAN YESTERDAY.

TONIGHT-THURSDAY:
UPPER LEVEL RIDGE IS PROGGED TO GRADUALLY BUILD OVER OUR REGION
THROUGH THURSDAY. HOWEVER....WE MAY HAVE TO DEAL WITH ANOTHER
BREEZY DAY ON WEDNESDAY AS STRONGER JET ENERGY STARTS DIVING
SOUTHEAST IN RESPONSE TO ANOTHER UPPER LEVEL TROF MOVING FROM
MONTANA INTO THE NORTHERN PLAINS. THIS UPPER LEVEL TROF WILL ALSO
CAUSE A DRY FRONTAL BOUNDARY TO PUSH THROUGH THE AREA WEDNESDAY
NIGHT. THE NORTHERN PANHANDLE WILL MOST LIKELY SEE THE GREATEST
IMPACT BEHIND THIS BOUNDARY WITH SOME GUSTS UP TO 30 MPH.
OTHERWISE...CLEARING SKIES WILL BE THE RULE. THURSDAY LOOKS TO BE
ANOTHER MILD DAY WITH LESS WIND AS THE UPPER LEVEL RIDGE BUILDS
OVER THE AREA. HOWEVER...THE MODELS ARE ADVERTISING QUITE A BIT OF
CIRRUS IN PLACE WHICH MAY LIMIT THE FULL SUN POTENTIAL. WEDNESDAY
AND THURSDAY WILL MOST LIKELY SEE TEMPERATURES IN THE 60S EAST OF
THE LARAMIE RANGE WITH 50S WEST OF THE RANGE AND 40S IN THE
MOUNTAINS.

.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 236 AM MDT TUE OCT 28 2014

THURSDAY NIGHT/FRIDAY...RIDGE AXIS ALOFT MOVES OVERHEAD AND THEN
JUST EAST OF OUR COUNTIES. SOUTHWEST FLOW ALOFT WILL INDUCE DECENT
SURFACE LEE TROUGHING...PRODUCING A MILD AND DRY DAY FOR
HALLOWEEN...AND A NEAR PERFECT DAY FOR OUTDOOR ACTIVITIES INCLUDING
TRICK OR TREATING FOR THE KIDS.

SATURDAY...POTENT NEGATIVELY TILTED SHORTWAVE TROUGH ALOFT ROTATES
UP THROUGH WESTERN WYOMING...WITH OUR COUNTIES REMAINING IN THE WARM
SECTOR WITH HIGH TEMPERATURES WILL INTO THE 60S EAST OF INTERSTATE
25. FEW LATE AFTERNOON SHOWERS POSSIBLE OVER THE SIERRA MADRE RANGE
WITH THE SHORTWAVE TROUGH...THOUGH DRY WEATHER PREVAILS ELSEWHERE.

SUNDAY...PROGRESSIVE SHORTWAVE TROUGH ALOFT ROTATES INTO EASTERN
MONTANA AND NORTH DAKOTA...SENDING A RATHER POTENT PACIFIC ORIGIN
COLD FRONT ACROSS OUR COUNTIES...THOUGH PRECIPITATION CHANCES WILL
BE LIMITED BY THE LACK OF LOW AND MID LEVEL MOISTURE AND DOWNSLOPING
WINDS IN THE LOWER LEVELS OF THE ATMOSPHERE.

MONDAY...SEASONABLY COOL AND BREEZY IN THE WAKE OF THE INITIAL
SHORTWAVE TROUGH ALOFT PASSAGE.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 528 AM MDT TUE OCT 28 2014

VFR. SCATTERED TO BROKEN CLOUDS AT OR ABOVE 10000 FEET AGL.
WINDS GUSTING 20 TO 30 KNOTS FROM LATE THIS MORNING THROUGH
THIS AFTERNOON.


&&

.FIRE WEATHER...
ISSUED AT 236 AM MDT TUE OCT 28 2014

DRY WEATHER WILL CONTINUE TO BE IN PLACE DURING THE NEXT FEW
DAYS. FUELS ARE STILL FAVORABLE IN ZONES 301, 311-313 FOR RAPID
SPREADING OF FIRES. GUSTY WEST WINDS AT 20 TO 30 MPH DURING THE
NEXT COUPLE OF DAYS WILL ALSO AFFECT ANY FIRE THAT DOES DEVELOP.

&&

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

$$

UPDATE...MJ
SHORT TERM...REC
LONG TERM...SAR
AVIATION...SAR
FIRE WEATHER...REC



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