Area Forecast Discussion
Issued by NWS Cheyenne, WY

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FXUS65 KCYS 021750
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
1150 AM MDT TUE SEP 2 2014

.SHORT TERM...(TODAY THROUGH THURSDAY NIGHT)
ISSUED AT 320 AM MDT TUE SEP 2 2014

CLEAR SKIES AND COOL TEMPERATURES TO START OFF THIS MORNING.
TEMPERATURES WILL RAPIDLY WARM FOLLOWING SUNRISE WITH SUNNY SKIES
PREVAILING ACROSS THE FORECAST AREA. GUSTY WEST WINDS WILL QUICKLY
DEVELOP AFTER SUNRISE...ESPECIALLY ALONG AND WEST OF THE LARAMIE
RANGE. BY THIS AFTERNOON WEST WINDS WILL FREQUENTLY GUST 40 TO 50
MPH IN WESTERN AREAS. NOT SO WINDY IN THE EAST AS BOUNDARY LAYER
AND FREE ATMOSPHERE WINDS WILL NOT COUPLE SO EASILY. REGARDLESS
SHOULD SEE GUSTS 15 TO 25 MPH IN THE NEBRASKA PANHANDLE BY MID
AFTERNOON. CHANCES FOR PRECIPITATION IS ZERO ACROSS NEARLY THE
ENTIRE FORECAST AREA TODAY...BUT THE MODELS ARE SHOWING SOME
INSTABILITY NEAR SIDNEY LATE THIS AFTERNOON SO CAN NOT COMPLETELY
RULE OUT AN ISOLATED THUNDERSTORM NEAR SIDNEY BUT IT LOOKS LIKE
THE BETTER CHANCES WILL BE JUST TO THE EAST SO KEPT MENTION OF
THUNDERSTORMS OUT OF THE FORECAST FOR NOW.

WINDS WILL SUBSIDE QUICKLY THIS EVENING WITH THE LOST
OF DAYTIME HEATING. LIGHT WINDS AND CLEAR SKIES TONIGHT WILL
GENERALLY ALLOW TEMPERATURES TO DIP INTO THE MID 40S TO MID 50S
ACROSS THE AREA. MOST OF THE FORECAST AREA HAS NO CHANCE FOR
PRECIPITATION TONIGHT BUT THERE WILL BE AN AREA OF ELEVATED
INSTABILITY ALONG THE I80 CORRIDOR FROM AROUND CHEYENNE...EAST
INTO THE SOUTHERN NEBRASKA PANHANDLE. ELEVATED LAPSE RATES AT
SIDNEY LATE TONIGHT ARE AROUND 9 DEG/KM WITH ELEVATED CAPE AROUND
1000 J/KG...SO IS WONT TAKE MUCH TO PERTURB THE ATMOSPHERE AND
PRODUCE A STORM OR TWO. MODELS ARE BEING STINGY PRODUCING
PRECIPITATION SO FOR NOW LEFT POPS BELOW 15 PERCENT...BUT
CERTAINLY SOMETHING TO TAKE A CLOSER LOOK AT LATER TODAY.

ZONAL FLOW WILL DOMINATE WEDNESDAY KEEPING THE FORECAST AREA DRY
AND WINDY. GUSTS OF 30 TO 40 MPH WILL BE COMMON ACROSS SOUTHEAST
WYOMING BY WEDNESDAY AFTERNOON AND 20 TO 25 FOR MOST OF THE
NEBRASKA PANHANDLE. TEMPERATURES WILL BE VERY WARM WITH HIGHS IN
THE 90S ACROSS THE PANHANDLE AND 80S FARTHER WEST. A COLD FRONT
WILL MOVE THROUGH THE AREA WEDNESDAY NIGHT. THE MODELS HAVE
TRENDED FASTER AND COOLER WITH THE FRONT OVER THE LAST FEW DAYS.
WITH UPSLOPE EAST WINDS THURSDAY TEMPERATURES WILL PROBABLY NOT
REACH 70 FOR PLACES LIKE CHEYENNE AND DOUGLAS BUT IN GENERAL
HIGHS WILL BE IN THE 70S FOR THURSDAY. CHANCES FOR PRECIPITATION
WILL BE LOW THURSDAY WITH ONLY A FEW LIGHT SHOWERS POSSIBLE MAINLY
IN THE MOUNTAINS.

.LONG TERM...(FRIDAY THROUGH MONDAY)
ISSUED AT 320 AM MDT TUE SEP 2 2014

NORTHERN EDGE OF MONSOONAL MOISTURE WILL BE QUITE CLOSE TO THE CWA
FRIDAY WITH SOME POSSIBLY TRICKLING OVER SOUTHERN PORTIONS THOUGH
IT WILL BE HINDERED BY INCREASINGLY WESTERLY FLOW ALOFT. WILL
MAINTAIN SOME LOW POPS OVER PARTS OF THE CWA FOR THIS WITH SOME
INDICATION OF A WEAK IMPULSE RIDING ACROSS IN THE FLOW FRIDAY
AFTERNOON AND EVENING. SIMILAR SETUP FOR SATURDAY AND SUNDAY WITH
WIDELY SCTD AFTERNOON AND EVENING CONVECTION THOUGH MOST ACTIVITY
SHOULD BE OVER AND CLOSE TO THE SE WY MTNS. ACTIVITY MAY BE ABLE
TO SPREAD FARTHER EAST OVER THE PLAINS MONDAY AS A SIGNIFICANT
UPPER TROF MOVES OUT OF SW CANADA INTO THE NW PART OF THE COUNTRY
AND WEAK IMPULSES ROUND ITS BASE AND CROSS THE AREA. TEMPS MILD
FRIDAY AND SATURDAY THEN WARMING A BIT FOR SUNDAY AND MONDAY AS
700MB TEMPS RISE IN SW FLOW AHEAD OF THE UPPER TROF.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY MORNING)
ISSUED AT 1149 AM MDT TUE SEP 2 2014

VFR CONDITIONS WILL PREVAIL AT ALL SITES THROUGH THE PERIOD. GUSTY
SOUTHWEST WINDS WILL BE COMMON TODAY...WITH 20 TO 30 KTS POSSIBLE
FOR WYOMING AND 15 TO 20 KTS AT THE NEBRASKA AIRPORTS. COULD SEE
AN ISOLATED SHOWER NEAR KSNY LATE THIS AFTERNOON AND EVENING...BUT
CONFIDENCE IS LOW THAT THIS WILL MATERIALIZE SO WILL LEAVE IT OUT
OF THE TAF FOR NOW. WINDS WILL EASE THIS EVENING FOR MOST
AREAS...WITH BREEZY CONDITIONS EXPECTED TO LINGER NEAR KCDR
THROUGH THE EARLY OVERNIGHT PERIOD. GUSTY WINDS WILL RETURN ON
WEDNESDAY.

&&

.FIRE WEATHER...
ISSUED AT 320 AM MDT TUE SEP 2 2014

DRY AND WINDY WILL BE THE CASE ACROSS SOUTHEAST WYOMING TODAY AND
WEDNESDAY. WINDS WILL GUST 40 TO 50 MPH ACROSS CARBON COUNTY THIS
AFTERNOON WITH HUMIDITY VALUES DROPPING AS LOW AS 10 PERCENT.
WINDS WILL NOT BE QUITE SO STRONG FARTHER EAST BUT STILL LOOKING
AT GUSTS TO 30 MPH AS FAR EAST AS THE NEBRASKA BORDER THIS
AFTERNOON. NO CHANCES FOR PRECIPITATION TODAY WITH THE EXCEPTION
OF AROUND SIDNEY NEBRASKA WHERE THERE IS A VERY SMALL CHANCE FOR A
LATE AFTERNOON THUNDERSTORM.

FOR WEDNESDAY TEMPERATURES IN THE 80S OVER SOUTHEAST WYOMING AND
90S INTO THE PANHANDLE WILL HELP PRODUCE VERY LOW HUMIDITY VALUES.
RELATIVE HUMIDITY VALUES WILL DROP INTO THE UPPER SINGLE DIGITS TO
MID TEENS OVER MOST PLACES OUTSIDE OF THE MOUNTAINS. WINDS WILL
GENERALLY GUST 30 TO 40 MPH OVER SOUTHEAST WYOMING IN THE
AFTERNOON BUT NOT SO WINDY IN THE PANHANDLE. FIRE WEATHER WATCHES
AND WARNINGS ARE IN PLACE FOR TODAY AND WEDNESDAY AFTERNOON.

&&

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...FIRE WEATHER WATCH FROM WEDNESDAY AFTERNOON THROUGH WEDNESDAY
     EVENING FOR WYZ301-302-304-306-309-310.

     RED FLAG WARNING UNTIL 7 PM MDT THIS EVENING FOR WYZ301-302-304-
     309.

NE...NONE.
&&

$$

SHORT TERM...SML
LONG TERM...RE
AVIATION...RJM
FIRE WEATHER...SML





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