Area Forecast Discussion
Issued by NWS Riverton, WY

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

000
FXUS65 KRIW 011630
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
1030 AM MDT MON SEP 1 2014

.SHORT TERM...TODAY THROUGH WEDNESDAY NIGHT

THE LAST SHORT WAVE THAT COULD STIR UP MORE SHOWERS AND STORMS MOVES
THROUGH TODAY WITH EVENTUAL CLEARING WEST TO EAST AS THE MAIN TROUGH
CONTINUES TO MOVE INTO THE PLAINS. A FEW STRONGER STORMS MAY OCCUR
OVR JOHNSON COUNTY BY EARLY AFTERNOON WHERE SOME USEFUL MOISTURE
WILL STILL BE LEFTOVER...CAPE WILL BE MARGINAL BUT SHEAR WILL BE
DECENT AROUND A LEFTOVER BOUNDARY. THERE WILL ALSO BE SOME CONTINUED
BREEZY CONDITIONS AS THE SUBSIDENT SIDE OF THE TROUGH SWINGS THROUGH
AND FLOW SHIFTS TO THE NORTHWEST.

MUCH DRIER AIR MOVES IN ON TUESDAY AS FLOW TURNS MORE ZONAL. HIGH
PRESSURE BUILDING IN FROM THE SOUTH WILL ALSO BRING SOME WARMER AIR
WITH TEMPERATURES REBOUNDING BACK TO NEAR 80 EAST OF THE DIVIDE. THERE
COULD BE SOME GUSTS TO 30 MPH ACROSS THE SOUTH ON TUESDAY...WHICH
COULD LEAD TO SOME FIRE WEATHER CONCERNS IN AREAS WITH FLASHY GRASSY
FUELS.

WEDNESDAY...SOME MODEL SOLUTIONS ARE ADVERTISING ANOTHER UPPER LEVEL
TROUGH WITH SHARP COLD FRONT AND BAROCLINIC ZONE DROPPING SOUTH INTO
MONTANA...AT THIS TIME IT LOOKS LIKE WE WOULD NOT SEE MUCH FROM THE
FRONT UNTIL LATE WITH NOT MUCH PRECIPITATION MAKING IT THIS FAR
SOUTH...BUT COOLER TEMPERATURES AND A WIND SHIFT TO THE NORTH IS
EXPECTED IF THIS SCENARIO ACTUALLY PLAYS OUT AS ADVERTISED.
INTRODUCED SOME SLIGHT CHANCE POPS ACROSS THE NORTHERN MOUNTAINS TO
ACCOUNT FOR THIS POSSIBILITY. OTHERWISE...THE WARMING TREND
CONTINUES ACROSS THE SOUTH WITH STEADY 20 TO 30 KNOT SOUTHWESTERLIES
AND CONTINUED FIRE WEATHER CONCERNS AS MIN RHS ARE EXPECTED TO DROP
INTO THE TEENS AGAIN ON WEDNESDAY AFTERNOON.

.LONG TERM...THURSDAY THROUGH MONDAY

THE GFS AND ECMWF MODELS ARE IN AGREEMENT WITH THE COLD FRONT
PUSHING SOUTH INTO CENTRAL WY THURSDAY. THE ECMWF IS STILL COOLER
AND TAKES THE FRONT WEST OF THE DIVIDE WHILE THE GFS HAS LESS
COOLING WEST OF THE DIVIDE. MADE SOME HIGH TEMP ADJUSTMENTS FROM
PREVIOUS FORECAST BUT OVERALL THE TREND IS TO GO COOLER EAST OF THE
DIVIDE AND NW WY WITH LESS COOLING IN THE SOUTH AND SOUTHWEST. THE
PRECIP CHANCE IS STILL A BIT MESSY AS THE 00Z MODELS ARE DRIER THAN
PREVIOUS RUNS. I WILL KEEP ISOLATED SHOWERS/STORMS THURS PM AND EVE.
FRIDAY LOOKS TO BE COOL EAST OF THE DIVIDE AND MILD WEST OF THE
DIVIDE AS THE FRONT SHOULD LIE ALONG THE DIVIDE. AGAIN ISOLATED
SHOWERS AND STORMS FRIDAY AFTERNOON AND EVENING. SATURDAY AND SUNDAY
WILL FEATURE ISOLATED AFTERNOON AND EVENING SHOWERS AND STORMS AS
MOISTURE WILL BE AROUND AS WELL AS THE LINGERING FRONTAL BOUNDARY.
THE ECMWF MODEL IS DRIER THAN THE GFS BOTH DAYS AS IT PUSHES THE
MOISTURE TO MAINLY SOUTHERN WY. NOT SURE THAT WILL HAPPEN SO WENT
WITH THE CONSISTENT GFS. NEXT MONDAY LOOKS DRIER BUT ISOLATED
MOUNTAIN SHOWERS/STORMS WILL STILL OCCUR OVER AND NEAR THE
MOUNTAINS. TEMPS WILL WARM A FEW DEGREES PER DAY SATURDAY THROUGH
NEXT MONDAY.

.AVIATION.../18Z ISSUANCE/

A LAST IN A SERIES OF UPPER LEVEL DISTURBANCES IN NW FLOW WILL RACE
SE ACROSS NORTHERN WYOMING THIS AFTERNOON. AREAS OF MVFR/IFR CIGS
WITH SCT -SHRA...SNOW LEVELS NEAR 9.5KFT WITH FRQT MTN
OBSCURATIONS ...WILL SPREAD ACROSS NORTHERN WYOMING FROM
YELLOWSTONE NATIONAL PARK TO A VCNTY AND NORTH OF KCOD-KBYG LINE
18Z-00Z. MOST OF THIS ACTIVITY WILL PUSH FROM VCNTY OF THE BIGHORN
RANGE AND EASTWARD EARLY EVENING.  W-NW WIND AT 15-25KT AND MAINLY
SKC CONDITIONS WILL PREVAIL ACROSS THE SOUTHERN THIRD OF THE AREA
IN THE AFTERNOON.

SKC CONDITIONS WITH DIMINISHING WIND...PATCHY FOG IN THE WESTERN
VALLEYS...WILL PREVAIL MONDAY NIGHT.

NOTE...FAA INFORMS NWS THAT OBSERVATION FRO KCOD WILL BE UNAVAILABLE
UNTIL SOMETIME TUESDAY WHEN REPAIRS ARE EXPECTED.  TAF CONTINUED AS
VFR CONDITIONS ARE ANTICIPATED AT KCOD THROUGH THE FORECAST PERIOD.

.FIRE WEATHER...

FIRE DANGER WILL BE RELATIVELY LOW FOR ANOTHER DAY. ISOLATED SHOWERS
AND THUNDERSTORMS WILL CONTINUE ACROSS NORTHERN WYOMING THROUGH THE
AFTERNOON. ACROSS THE SOUTH...WEST WINDS CONTINUE AT 15-25 MPH WITH
GUSTS TO 40 MPH POSSIBLE ALONG WITH MINIMUM RH VALUES ONLY DROPPING
TO 20 PERCENT AT THE LOW END. MUCH DRIER AND WARMER ON TUESDAY AND
WEDNESDAY WITH THE WINDS GUSTING OVER 30 MPH EACH AFTERNOON ACROSS
THE SOUTH...POTENTIALLY INCREASING FIRE DANGER ACROSS RAWLINS
DISPATCH AND PORTIONS OF CASPER AND CODY DISPATCH.

&&

.RIW WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SHORT TERM...ALLEN
LONG TERM...AR
AVIATION...C.BAKER
FIRE WEATHER...ALLEN







USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.