Area Forecast Discussion
Issued by NWS Cheyenne, WY

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000
FXUS65 KCYS 071753
AFDCYS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
1153 AM MDT TUE JUL 7 2015

.SHORT TERM...(TODAY THROUGH WEDNESDAY NIGHT)
ISSUED AT 349 AM MDT TUE JUL 7 2015

A LOW LEVEL SOUTHEASTERLY UPSLOPE FLOW HAS PRODUCED WIDESPREAD
MODERATE DRIZZLE THROUGH THE LATE NIGHT AND EARLY MORNING HOURS
FROM THE I-80 SUMMIT DOWN THROUGH CHEYENNE AND PINE BLUFFS...BUT
THE DRIZZLE IS BECOMING LESS WIDESPREAD AND THE SOUTHEASTERLY FLOW
HAS WEAKENED A BIT HERE SHORTLY BEFORE DAWN. WILL KEEP A MENTION
OF DRIZZLE IN THROUGH MID MORNING...AND WILL KEEP WIDESPREAD LOW
CLOUDS IN EAST OF THE LARAMIE RANGE THROUGH LATE MORNING BEFORE WE
SEE BREAKS. OTHERWISE...WE SEE SOME SCATTERED MOSTLY LIGHT SHOWERS
MOVING ACROSS THE SNOWY AND SOUTH LARAMIE RANGE EARLY THIS MORNING
THAT WILL AFFECT PORTIONS OF ALBANY AND LARAMIE COUNTIES THROUGH
MID MORNING...SO WILL KEEP A CHANCE OF SHOWERS GOING THIS MORNING
FOR THOSE AREAS. BY LATE MORNING...WE EXPECT TO SEE SCATTERED
SHOWERS AND ISOLATED THUNDERSTORMS FORMING ACROSS THE WEST
BECOMING MORE NUMEROUS AS A SHORTWAVE TROUGH INTERACTS WITH A
STATIONARY BOUNDARY IN THE AFTERNOON HOURS. MANY AREAS OUT ACROSS
CARBON AND ALBANY COUNTIES RECEIVED A HALF INCH OF RAIN
YESTERDAY...WITH SOME LOCATIONS RECEIVING NEARLY 2 INCHES OF
RAINFALL OVER THE PAST 48 HOURS. MODEL SOUNDINGS ARE DEEPLY
SATURATED SHOWING AROUND 1 INCH OF PRECIPITABLE WATER TODAY INTO
TONIGHT...AND STORM MOTIONS ONLY AROUND 13 KNOTS. WITH THAT IN
MIND...AND WITH THE FACT THAT THE GROUNDS IN SOME AREAS OF CARBON
AND SOUTH ALBANY COUNTIES ARE SATURATED...WE POSTED A FLASH FLOOD
WATCH FOR THOSE AREAS VALID FOR THIS AFTERNOON AND EVENING. THE
GREATEST COVERAGE OF STORMS THIS AFTERNOON AND EVENING ARE
EXPECTED TO BE CHEYENNE TO DOUGLAS WESTWARD...WITH LESS COVERAGE
ACROSS THE NEBRASKA PANHANDLE WHERE PERSISTENT LOW CLOUDS IN THE
SOUTHERLY UPSLOPE FLOW (MOST AREAS) WILL KEEP THINGS A BIT MORE
STABILIZED INTO THE MID AFTERNOON.

OTHERWISE...WE KEEP A CHANCE OF SHOWERS AND THUNDERSTORMS GOING
AGAIN ON WEDNESDAY AS WE REMAIN UNDERNEATH AN ACTIVE WESTERLY
UPPER FLOW IN A DEEPLY SATURATED AIRMASS. THERE IS THE POSSIBLITY
THAT THE FLASH FLOOD WATCH MAY HAVE TO BE MODIFIED OR EXTENDED
INTO WEDNESDAY BASED ON TRENDS TODAY AND WHERE THE HEAVIEST STORMS
FOCUS TOMORROW. STAY TUNED.

.LONG TERM...(THURSDAY THROUGH MONDAY)
ISSUED AT 349 AM MDT TUE JUL 7 2015

WET PATTERN TO CONTINUE IN THE LONG TERM FORECAST. GFS SOUNDINGS
ACROSS THE CWFA SHOWING PWATS OF .8 INCHES NEAR RAWLINS TO WELL
OVER AN INCH IN THE PANHANDLE. ALL THATS NEEDED IS AN UPPER LEVEL
DISTURBANCE TO MOVE OVER THE AREA AND CONVECTION WILL FIRE OFF.
FORECAST CHALLENGES DEAL WITH TIMING OF THESE DISTURBANCES.

STARTING OFF THURSDAY...ECMWF SHOWS AN UPPER SHORTWAVE BEING
KICKED OFF A LOW PRESSURE CENTER IN SOUTHERN NEVADA...MOVING
THROUGH THE AREA DURING THE LATE MORNING AND AFTERNOON. AREAS
WEST OF THE LARAMIE RANGE LOOK TO BE THE BEST LOCATION FOR
AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS.

THE LOW ITSELF TRACKS TO THE NORTHEAST ON FRIDAY...TRACKING
THROUGH NORTHWESTERN WYOMING INTO WESTERN MONTANA FRIDAY
AFTERNOON/EVENING. SHOWERS AND THUNDERSTORMS EXPECTED ONCE AGAIN
AS THIS HAPPENS WITH BEST CHANCES AGAIN WEST OF THE LARAMIE RANGE.

THE WEEKEND LOOKS MAINLY DRY AND KEPT POPS OUT OF THE FORECAST.
UPPER RIDGE MOVES OVER THE AREA AND PERSISTS INTO THE BEGINNING OF
NEXT WEEK. NEED TO BE WATCHING MONSOON MOISTURE THOUGH AS BOTH THE
GFS AND ECMWF HAVE IT OVER WESTERN COLORADO.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1148 AM MDT TUE JUL 7 2015

MAINLY VFR CONDITIONS THROUGH THE EVENING. MVFR VIS IN HAZE/SMOKE
WILL CONTINUE AT CYS OVER THE NEXT FEW HOURS. SCATTERED SHOWERS
AND THUNDERSTORMS WILL DEVELOP THROUGH THE AFTERNOON ACROSS
SOUTHEAST WYOMING. BRIEF MVFR VIS WILL BE POSSIBLE IN HEAVIER RAIN
SHOWERS. SOUTH TO SOUTHEAST WINDS WILL GUST TO 15-25 KTS THROUGH
THE EARLY EVENING ACROSS THE PLAINS.

&&

.FIRE WEATHER...
ISSUED AT 349 AM MDT TUE JUL 7 2015

A MOSTLY WET WEATHER PATTERN WILL CONTINUE THROUGH THURSDAY WITH
INCREASED COVERAGES OF SHOWERS AND THUNDERSTORMS ACROSS SOUTHEAST
WYOMING INTO THE WESTERN NEBRASKA PANHANDLE. AS HIGH PRESSURE
BUILDS IN FROM THE SOUTHEAST THIS WEEKEND...THE WEATHER PATTERN IS
EXPECTED TO BECOME DRIER BY SATURDAY. TEMPERATURES WILL REMAIN
BELOW NORMAL THROUGH MUCH OF THIS WEEK WHILE THE WET PATTERN
CONTINUES. THEREFORE...NO FIRE WEATHER CONCERNS ARE ANTICIPATED IN
THE NEAR TERM.

&&

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...FLASH FLOOD WATCH THROUGH THIS EVENING FOR WYZ109>116.

NE...NONE.
&&

$$

SHORT TERM...JG
LONG TERM...GCC
AVIATION...ZF
FIRE WEATHER...JG


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