Area Forecast Discussion
Issued by NWS Cheyenne, WY

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FXUS65 KCYS 290108
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
708 PM MDT MON JUL 28 2014

.UPDATE...
ISSUED AT 700 PM MDT MON JUL 28 2014

IN OUR GRIDDED FORECASTS...WE HAVE UPDATED THE AREAL COVERAGE FOR
THUNDERSTORMS EARLY THIS EVENING BASED ON OUR CHEYENNE AND DENVER
WSR-88D REFLECTIVITY LOOPS SHOWING NUMEROUS SHOWERS AND
THUNDERSTORMS OVER EASTERN LARAMIE AND WESTERN KIMBALL COUNTIES
FROM BURNS TO PINE BLUFFS TO BUSHNELL AND KIMBALL. ALSO ADJUSTED
QPF GRIDS TO MATCH EXPECTED RAINFALL.

UPDATE ISSUED AT 547 PM MDT MON JUL 28 2014

CHEYENNE AND DENVER WSR-88D REFLECTIVITIES INDICATING
ISOLATED SLOW MOVING THUNDERSTORMS FROM CHEYENNE TO SIDNEY...
WITH MORE ISOLATED THUNDERSTORMS WEST OF INTERSTATE 25. BASED
ON RADAR...SATELLITE AND OBSERVATIONAL TRENDS...HAVE BUMPED UP
OUR POPS TO INCLUDE ISOLATED TO SCATTERED THUNDERSTORMS THROUGH
EARLY THIS EVENING WITH A MENTION OF LOCALLY HEAVY RAIN FROM
STORMS DUE TO SLOW STEERING WINDS AND PRECIPITABLE WATER VALUES
FROM 125 TO 150 PERCENT OF NORMAL.

&&

.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT)
ISSUED AT 224 PM MDT MON JUL 28 2014

QUIET WEATHER SO FAR THIS AFTERNOON WITH JUST A BIT OF CONVECTION
OVER THE FAR SRN MTNS. DO NOT SEE MUCH ACTIVITY SPREADING EAST
INTO THIS EVENING AS MONSOONAL MOISTURE REMAINS TO THE WEST AND
SOUTHWEST. THIS MOISTURE WILL SPREAD ACROSS THE CWA LATER TONIGHT
AND COULD SEE SOME SHOWERS FORM OVER MAINLY NORTHERN AND WESTERN
PARTS OF THE CWA AS IT DOES SO.

MAIN ATTENTION WILL BE FOR TUESDAY AFTERNOON INTO WEDNESDAY AS
AMPLE MOISTURE OVER THE REGION INTERACTS WITH SOME SHORTWAVE
ENERGY DROPPING EAST-SOUTHEAST ACROSS THE AREA AN DECENT
INSTABILITY. SHOULD SEE FAIRLY WIDESPREAD SHOWERS AND ISOLATED
TSTMS DEVELOP TUESDAY MORNING AND AFTERNOON WITH THE MOST FAVORED
AREA BEING SE WYOMING OVER AND CLOSE TO THE MTNS WHERE UPSLOPE
FLOW WILL BE ENHANCED. INDIVIDUAL STORMS LIKELY TO BE SLOW MOVING
WITH HEAVY RAINS POSSIBLE IN SOME AREAS. MODELS HAVE TRENDED
FASTER WITH THE PCPN AND PRETTY MUCH CLEAR IT OUT OF THE CWA BY
LATE WEDS MORNING. LOCALIZED FLASH FLOODING NOT OUT OF THE
QUESTION BUT RECENT DRYNESS AND FASTER MOVEMENT OF THE SYSTEM
WOULD TEND TO MITIGATE THE FLOOD POTENTIAL THUS HAVE OPTED TO HOLD
OFF ON A FLASH FLOOD WATCH. LATER SHIFTS MAY NEED TO REVISIT THIS
IF GENERAL QPF LOOKS TO BE HIGHER.  CLEARING CONDITIONS FOR
WEDNESDAY NIGHT. TEMPS COOLER OVER THE NEXT COUPLE DAYS WITH
CLOUDS AND PCPN.

.LONG TERM...(THURSDAY THROUGH MONDAY)
ISSUED AT 224 PM MDT MON JUL 28 2014

THE MAIN CONCERN WITH THIS PORTION OF THE FORECAST IS THE TIMING
OF THE WAVES RIDING OVER THE UPPER LEVEL RIDGE IN THE ROCKIES.

THURSDAY-FRIDAY:
MOSTLY QUIET WEATHER IS ON TAP FOR THE AREA ON THURSDAY AS A
FAIRLY STOUT UPPER LEVEL RIDGE KEEPS THE BULK OF THE MOISTURE
SUPPRESSED IN COLORADO AND NEW MEXICO. TEMPERATURES WILL NOT BE
OVERLY WARM EITHER WITH HIGHS GENERALLY IN THE 70S AND 80S.
MEANWHILE...THE MOISTURE IS PROGGED TO LIFT NORTH INTO OUR
FORECAST AREA ON FRIDAY AS AN UPPER LEVEL WAVE MOVES THROUGH THE
NORTHERN ROCKIES. THIS MAY BRING SOME SHOWERS AND ISOLATED
THUNDERSTORMS TO THE AREA...BUT WITH LIMITED CAPE (LESS THAN 500
J/KG) WE ARE NOT EXPECTING ANYTHING SEVERE.

SATURDAY-MONDAY:
A FAIR STRONG UPPER LEVEL WAVE IS EXPECTED TO PUSH SOUTHEAST
ACROSS THE NORTHERN PLAINS THIS WEEKEND. THIS WILL CAUSE A FRONTAL
BOUNDARY TO SURGE THROUGH AREAS EAST OF THE LARAMIE RANGE. AHEAD
OF AND ALONG THIS FRONT...WE MAY SEE THE POTENTIAL FOR WIDELY
SCATTERED STRONG TO SEVERE THUNDERSTORMS AS THE 0-6KM SHEAR
INCREASES TO 30 TO 40 KTS WITH CAPE VALUES INCREASING TO ABOVE
500J/KG. WE WILL NEED TO KEEP AN EYE ON THIS TIMEFRAME ESPECIALLY
IF THIS WAVE TRANSVERSES A LITTLE FURTHER WEST THAN WHAT THE GFS
PROGS. TEMPERATURE WISE WE WILL CONTINUE TO BE ON THE WARM SIDE
WITH HIGHS GENERALLY IN THE 70S AND 80S.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY AFTERNOON)
ISSUED AT 547 PM MDT MON JUL 28 2014

NEBRASKA AERODROMES...THROUGH 03Z ISOLATED SLOW MOVING
THUNDERSTORMS SOUTH OF A SCOTTSBLUFF TO BRIDGEPORT LINE PRODUCING
LOCALLY HEAVY RAIN...ERRATIC WIND GUSTS TO 40 KNOTS AND
TURBULENCE WITH LOCALIZED MVFR...OTHERWISE VFR.

03Z TO 15Z...PATCHY FOG AND LOW CLOUDS FROM 10Z TO 15Z WITH
LOCALIZED IFR AND MVFR. AREAL COVERAGE OF FOG GREATEST SOUTH OF A
SCOTTSBLUFF TO ALLIANCE LINE.

AFTER 15Z...SCATTERED TO NUMEROUS SHOWERS DEVELOPING IN THE
AFTERNOON...MOST NUMEROUS SOUTH OF A SCOTTSBLUFF TO ALLIANCE
LINE...WITH ISOLATED TO SCATTERED THUNDERSTORMS. MVFR IN SHOWERS
AND THUNDERSTORMS...WITH THUNDERSTORMS PRODUCING GUSTY AND
ERRATIC WINDS AND LOCALIZED TURBULENCE.

WYOMING AERODROMES...THROUGH 03Z ISOLATED SLOW MOVING
THUNDERSTORMS PRIMARILY EAST OF A WHEATLAND TO CHEYENNE LINE...
WITH LESS ISOLATED THUNDERSTORMS FURTHER WEST. A FEW THUNDERSTORMS
PRODUCING LOCALLY HEAVY RAIN...ERRATIC WIND GUSTS TO 40 KNOTS
AND TURBULENCE WITH LOCALIZED MVFR...OTHERWISE VFR.

03Z TO 15Z...PATCHY FOG AND LOW CLOUDS FROM 10Z TO 15Z AT LARAMIE
AND CHEYENNE WITH MOUNTAIN OBSCUREMENT. LOCALIZED IFR AND MVFR
IN LOW CLOUDS AND FOG.

AFTER 15Z...SCATTERED TO NUMEROUS SHOWERS DEVELOPING IN THE
AFTERNOON...MOST NUMEROUS EAST OF A LARAMIE TO WHEATLAND LINE...
WITH MOUNTAINS OBSCURED. ISOLATED TO SCATTERED AFTERNOON
THUNDERSTORMS...PRODUCING GUSTY AND ERRATIC WINDS AND LOCALIZED
TURBULENCE.


&&

.FIRE WEATHER...
ISSUED AT 224 PM MDT MON JUL 28 2014

CONCERNS EXPECTED TO BE LOW OVER AT LEAST THE NEXT FEW DAYS WITH
NON-CRITICAL WEATHER CONDITIONS EXPECTED. WETTING RAINS LOOK
LIKELY OVER MUCH OF THE AREA TUESDAY AFTERNOON INTO WEDNESDAY
ESPECIALLY OVER AND CLOSE TO THE MTNS WHERE PCPN SHOULD BE
ENHANCED BY OROGRAPHIC LIFT.

&&

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

$$

UPDATE...RUBIN
SHORT TERM...RE
LONG TERM...REC
AVIATION...RUBIN
FIRE WEATHER...RE





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