Area Forecast Discussion
Issued by NWS Cheyenne, WY

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000
FXUS65 KCYS 270948
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
348 AM MDT MON OCT 27 2014

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 317 AM MDT MON OCT 27 2014

TODAY...LOOKING AT OUR RADAR REFLECTIVITY TRENDS...EXPECT THE BULK
OF THE SHOWERS TO BE EAST OF OUR WESTERN NEBRASKA COUNTIES PRIOR TO
DAYBREAK. WILL BE A RAW...BREEZY TO WINDY...AND COOLER DAY IN THE
WAKE OF THE COLD FRONTAL PASSAGE...AND WITH PROGGED SURFACE THROUGH
700 MB GRADIENTS.

DESPITE THE SHORTWAVE TROUGH ALOFT MOVING EAST OF
OUR COUNTIES IN THE AFTERNOON...WITH CYCLONIC CURVATURE
ALOFT...ALONG WITH A COLD POOL ALOFT AND ADEQUATE LOW AND MID LEVEL
MOISTURE...WE EXPECT AT LEAST ISOLATED AFTERNOON INSTABILITY
SHOWERS...LIMITED IN COVERAGE BY THE LOW LEVEL DOWNSLOPE WINDS.
THANK YOU FOR THE COORDINATION WITH OUR NEIGHBORS IN NORTH PLATTE
AND FOR THE HEADS UP BRIEFING FROM OUR EVENING SHIFT FORECASTER.

TONIGHT...COOL OVERNIGHT WITH DECREASING WINDS AND MOSTLY CLEAR
SKIES.

TUESDAY...DRY AND SEASONABLY COOL DAY WITH NORTHWEST FLOW ALOFT AND
LIMITED LOW AND MID LEVEL MOISTURE. WINDS WILL BE RATHER MINIMAL
BASED ON PROJECTED SURFACE THROUGH 700 MB GRADIENTS.

TUESDAY NIGHT...NOT QUITE AS COOL AS MONDAY NIGHT AS LOW LEVEL
GRADIENTS INCREASE IN RESPONSE TO APPROACHING SHORTWAVE TROUGH ALOFT
FROM WESTERN MONTANA AND IDAHO.

WEDNESDAY...DECENT WARMING TREND ON TAP AS THE NEXT LOW AMPLITUDE
SHORTWAVE TROUGH ALOFT MOVES ACROSS WYOMING AND EASTERN
MONTANA...INDUCING DOWNSLOPE WEST WINDS TO BOOST MAXIMUM
TEMPERATURES. CONTINUED DRY WITH MINIMAL LOW AND MID LEVEL
MOISTURE.

.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 317 AM MDT MON OCT 27 2014

THE MAIN CONCERN WITH THIS FORECAST PACKAGE IS HOW FAST WE WILL REBOUND
WITH REGARDS TO TEMPERATURES AT THE END OF THE WEEK.

WEDNESDAY NIGHT-FRIDAY:
THE MODELS ARE IN FAIRLY GOOD AGREEMENT WITH THE UPPER LEVEL
RIDGE BUILDING OVER THE ROCKIES DURING THIS TIMEFRAME. THE MAIN
QUESTION WILL BE HOW MUCH HIGH CLOUD COVER WILL SPILL OVER THE
RIDGE. THE GFS/ECMWF ARE BOTH ADVERTISING THIS CLOUD COVER WHICH
COULD LIMIT TEMPERATURES A BIT. HOWEVER...700MB STANDARDIZED
ANOMALIES ARE ABOUT 1.5 STANDARD DEVIATIONS ABOVE NORMAL FOR THIS
TIME OF YEAR. THE ABSENCE OF THIS CLOUD COVER COULD YIELD TO
TEMPERATURES WELL INTO THE MID TO UPPER 60S...ESPECIALLY AREAS
NORTH OF THE PINE RIDGE WHERE DOWNSLOPE FLOW MAY BE MORE
PREVALENT. THE REMAINDER OF THE AREA WILL SHOULD BE ABLE TO REACH
THE 50S AND 60S WITH GUSTY SOUTHEAST FLOW EAST OF THE LARAMIE
RANGE AND LIGHTER WINDS ALONG AND WEST OF THE LARAMIE RANGE.

SATURDAY-SUNDAY:
THE MODELS ARE SHOWING THE UPPER LEVEL TROF DIGGING INTO THE
NORTHERN ROCKIES WHICH WILL ALLOW FOR STRONGER SOUTHWEST FLOW TO
MOVE INTO THE REGION. WE DID BUMP UP WIND SPEEDS ON SATURDAY NIGHT ESPECIALLY
FOR THE GAP AREA AROUND ARLINGTON WHERE 700MB WIND SPEEDS COULD
REACH 50KTS. THESE HIGHER WIND SPEEDS MAY TRANSLATE EAST ON SUNDAY
AS THE TROF PUSHES EAST INTO THE NORTHERN PLAINS. THIS WILL FAVOR
QUITE A BIT OF DOWNSLOPE FLOW BEHIND THE FRONTAL BOUNDARY WHICH
PROGGED TO MOVE THROUGH THE REGION SATURDAY NIGHT. NOT EXPECTING
MUCH IN THE WAY OF PRECIPITATION WITH THIS SYSTEM AT THIS
TIME...DUE TO LIMITED MOISURE. HOWEVER...THIS SYSTEM IS SHOWING
SOME SIGNS OF NEGATIVE TILT WITH HEIGHT...AND A DECENT JET STREAK
MOVING THROUGH THE PANHANDLE EARLY SUNDAY MORNING WHICH MAY AID IN
DRAWING A BIT MORE MOISTURE INTO THE REGION SIMILAR TO THE
CURRENT SYSTEM. WE WILL KEEP THE BEST CHANCES FOCUSED ACROSS THE
NORTH FOR NOW...BUT WE MAY END UP HAVING TO BUMP UP POPS ACROSS
THE SOUTHERN PANHANDLE SUNDAY MORNING.


&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 602 PM MDT SUN OCT 26 2014

FORECAST FOCUS WAS THE TIMING...COVERAGE AND PHASE OF PRECIP THAT
WILL DEVELOP OVR SE WYOMING AND THE WRN NEBRASKA PANHANDLE THIS
EVENING AND CONTINUE TONIGHT...BEFORE DISSIPATING BY SUNRISE
MONDAY. LATEST RADAR RETURNS SHOW SHOWERS BEGINNING TO DEVELOP
OVR THE SNOWY RANGE...WITH SOME VERY WK RETURNS SW OF KBFF. EXPECT
THIS COVERAGE TO EXPAND THROUGH MIDNIGHT AS A FAST-MOVING STORMS
SYSTEM SWEEPS THROUGH. TEMPERATURES WILL BE WARM ENOUGH FOR RAIN
AT AREA TERMINALS...THOUGH KLAR AND KRWL WOULD BE CLOSE SHOULD
PRECIP BE CONSISTENT AND STRONG ENOUGH. THAT SAID...KEPT MOST
LOCATIONS VFR THROUGH THE PERIOD AS RAINFALL INTENSITY ISN`T
EXPECTED TO BE STRONG ENOUGH FOR VISIBILITY REDUCTION. THE CLOUD
DECK SHOULD STAY VFR AS WELL...BUT JUST BARELY IN SPOTS. WOULD NOT
BE SURPRISED TO SEE A BRIEF DIP INTO MVFR...BUT WASN`T CONFIDENT
IN LOCATION TO INCLUDE. CONDITIONS WILL IMPROVE AFTER 09Z OR 10Z
GIVING WAY TO BREEZY NORTHWEST WINDS FOR MONDAY.


&&

.FIRE WEATHER...
ISSUED AT 317 AM MDT MON OCT 27 2014

MINIMAL CONCERNS BASED ON PROJECTED HUMIDITIES AND
WINDS REMAINING ABOVE CRITICAL THRESHOLDS.

&&

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

$$

SHORT TERM...SAR
LONG TERM...REC
AVIATION...CAH
FIRE WEATHER...SAR



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