000
FXUS65 KRIW 192110
AFDRIW
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
310 PM MDT SAT JUL 19 2008
SHORT TERM...TONIGHT THROUGH TUESDAY
DRY AND STABLE DAY TODAY AS THE RIDGE BEGINS TO BUILD NWD. RIDGE
STARTS TO SHIFT EWD SUNDAY INTO MONDAY ALLOWING MONSOONAL MOISTURE
NEAR THE 4-CORNERS TO BEGIN MOVING NORTH. NAM IS A LITTLE FASTER
IN BRINGING THE MID LEVEL MOISTURE NWD AND GENERATES A FEW STORMS
ACROSS NOT ONLY THE FAR SW BUT ALSO THE FAR WEST ON SUNDAY. NOT
SURE WE`LL HAVE ENOUGH MOISTURE THAT FAR NORTH TO FIRE STORMS YET
SO WE WILL CONFINE THE ISOLD COVERAGE TO JUST OUR SW
ZONES...ESPECIALLY OFF THE UINTA MOUNTAINS. ON MONDAY...THE
MONSOON MOISTURE PLUME WILL OVERSPREAD ALL OF THE WEST AND PERHAPS
EVEN EAST OF THE DIVIDE. AT THE SAME TIME...THE MODELS ARE STILL
DEPICTING AN ELY SURGE INTO JOHNSON AND NATRONA COUNTIES MONDAY
AFTERNOON ALLOWING FOR A BETTER POTENTIAL FOR STRONGER STORMS.
MONDAY NIGHT...THE NAM12 IS SHOWING A GOOD SURGE OF LOW LEVEL
MOISTURE FROM THE SOUTH INCREASING H8 DEW POINTS INTO THE 50S EAST
OF THE DIVIDE AND 40S W. THE GFS IS NOT QUITE SO AGGRESSIVE. SOME
OF THE MOISTURE IN THE WIND RIVER BASIN IS FORECAST TO BE MIXED
OUT TUESDAY AFTERNOON WITH HIGHER DP`S HOLDING TO THE NORTH AND
EAST. HOWEVER...THE SURFACE CONVERGENCE BOUNDARIES OF THE NORTH
AND EAST WINDS WILL BE CLOSE BY IT APPEARS. TOO EARLY TO PINPOINT
THE HIGHEST THREAT BUT WE HAVE HIT THE MTNS AND NORTH WITH CHANCE
POPS ON TUESDAY FOR NOW.
LONG TERM...TUESDAY NIGHT THROUGH SATURDAY
IN THE WAKE OF THIS TUESDAY DISTURBANCE...DRIER AIR IS EXPECTED
TO PUSH INTO WESTERN WYOMING...WITH THE MONSOONAL MOISTURE
SUPPRESSED SOUTH OF THE AREA WEDNESDAY AND THURSDAY. THUS...HAVE
LOWERED POPS WEST OF THE DIVIDE WEDNESDAY AND THURSDAY...WITH THE
BEST SHOT OF CONVECTION ACROSS THE EAST WHERE BETTER MOISTURE AND
INSTABILITY IS EXPECTED. BY FRIDAY AND SATURDAY MEDIUM RANGE
MODELS INDICATE THAT THE MONSOON COULD PUSH INTO THE AREA...WITH
THE GFS SHOWING PRECIPITABLE WATER VALUES BY SATURDAY AFTERNOON
NEAR ONE INCH ACROSS MUCH OF THE CWA. HAVE ISOLATED POPS ACROSS
THE ENTIRE AREA FOR FRIDAY AND SATURDAY FOR THIS SCENARIO.
TEMPERATURES IN THE EXTENDED ARE EXPECTED TO BE SEASONAL TO
SLIGHTLY ABOVE AVERAGE.
AVIATION...
DRY AND STABLE ATMOSPHERE TODAY AND TONIGHT WILL LEAD TO VFR
CONDITIONS AT ALL TAF SITES. LATE AFTERNOON HEATING WILL ALLOW FOR
MIXING LEADING TO GUSTY WIND AT SOME SITES THROUGH EARLY EVENING.
SOUTHERLY RETURN MOISTURE FLOW WILL IMPACT MAINLY KRKS...KBPI...AND
KPNA WITH MORE HIGH-LEVEL CLOUD COVER ON SUNDAY. MID-LEVEL MOISTURE
CREEPING NORTH WILL ALSO ALLOW FOR MORE CUMULUS DEVELOPMENT AT THOSE
SITES. HOWEVER...DEEPER CONVECTION SHOULD BE LIMITED TO AREAS NEAR
THE COLORADO AND UTAH BORDERS WHERE BETTER MOISTURE AND INSTABILITY
EXIST. VFR CONDITIONS AND LIGHTER WIND TO PREVAIL SUNDAY.
FIRE WEATHER...
RH RECOVERY WILL BE RATHER LOW AGAIN ACROSS THE RED DESERT OVERNIGHT
WITH MAX RH`S ONLY IN THE 20S AND 30S. ON SUNDAY...THE BEGINNINGS OF
SOME MONSOONAL MOISTURE WILL SEEP INTO THE FAR SOUTHWEST WITH ISOLATED
GUSTY THUNDERSTORMS POSSIBLE LATE IN THE DAY. IT WILL BE EVEN WARMER
ON SUNDAY WITH CONTINUED LOW MIN RH`S. MORE MONSOONAL MOISTURE WILL
SPREAD ACROSS THE AREA MONDAY WITH ISOLATED THUNDERSTORMS ACROSS MOST
OF THE AREA. MIN RH`S SHOULD BEGIN TO INCREASE MONDAY INTO TUESDAY
AS MORE MOISTURE SPREADS UP FROM THE EAST AND SOUTH.
&&
.RIW WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...SKRBAC
LONG TERM...WM
AVIATION...CNJ
FIRE WEATHER...SKRBAC
