Area Forecast Discussion
Issued by NWS Riverton, WY

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000
FXUS65 KRIW 260447
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
1047 PM MDT TUE AUG 25 2015

.SHORT TERM...TONIGHT THROUGH WEDNESDAY (ISSUED AT 244 PM MDT)

SHORTWAVE PASSING JUST TO THE NORTH ACROSS SRN MT IS JUST SKIMMING
THE FAR NRN BORDER EARLY THIS AFTERNOON. FEW WEAK CONVECTIVE
ELEMENTS FORMING JUST SOUTH OF IT OVER THE ABSAROKAS WITH A LITTLE
BIT OF LIGHTNING STARTING TO SHOW UP. ANOTHER WEAK RIPPLE SPREADING
SOME BUILDING CU NEWD INTO THE SW/WCNTRL THIS WILL LIKELY LEAD TO
ISOLD STORMS ALONG ITS PATH INTO THE EVENING. LIMITED INSTABILITY TO
WORK WITH BUT STILL ENOUGH FOR ISOLD GUSTY STORMS WITH A LITTLE
LIGHTNING INTO THIS EVENING WITH A FEW LINGERING LIGHT
SHOWERS/SPRINKLES OVERNIGHT...MAINLY IN THE MTNS. WE THEN FOCUS ON
OUR DISTURBANCE(S) MOVING UP FROM THE DESERT SW. MAIN DISTURBANCE
STILL APPEARS TO BE THE ONE IN CENTRAL AZ WITH ANOTHER ONE POSSIBLE
NEAR THE AZ/CA/BAJA TRIPLE POINT. MODELS STILL WANT TO MAKE THIS WRN
ONE THE MAIN ONE WITH TIME WED INTO WED NIGHT BUT WE`LL JUST HAVE TO
WATCH THIS CLOSELY. DEEPER LL MOISTURE OVER AZ IS BEGINNING TO SURGE
NWD AND IS EXPECTED TO ARRIVE IN OUR SWRN ZONES WED MORNING AND THEN
CONTINUE LIFTING NWD THROUGH THE AFTERNOON. THE DEEPEST MOISTURE
WITH PW`S NEAR AN INCH WILL LIKELY REMAIN OVER THE SWRN QUARTER
THROUGH 00Z THU BEFORE LIFTING FURTHER NWD. MARGINAL CAPES TO WORK
WITH BUT FORECAST SOUNDINGS DO GENERATE SOME OVER THE FAR WEST AND
SRN ZONES WITH ENOUGH HEATING. OTHERWISE...THREAT OF SOME HEAVY
RAINERS WILL LIFT NWD WITH THIS BEST MOISTURE SURGE AT LEAST INTO
THE SWRN HALF BY 00Z THURSDAY.

.LONG TERM...WEDNESDAY NIGHT THROUGH TUESDAY

THE DISTURBANCE MOVING ALONG THE RIDGE WILL CONTINUE TO IMPACT THE
AREA WEDNESDAY NIGHT. MODELS CONTINUE TO SHOW THAT PRECIPITABLE
WATER WILL REMAIN INCREASED WITH THIS APPROACHING SYSTEM.
CONSEQUENTLY...IN ADDITION TO GUSTY WIND AND SMALL HAIL...STORMS
ASSOCIATED WITH THIS SYSTEM MAY PRODUCE PERIODS OF HEAVY RAINFALL.
THE DISTURBANCE WILL GENERALLY HAVE MOVED THROUGH THE AREA BY
THURSDAY AFTERNOON....WITH RIDGING REDEVELOPING ACROSS THE AREA.
EXPECT COOLER TEMPERATURES ACROSS THE AREA DUE TO THIS SYSTEM. SOME
TRAPPED MOISTURE IN THE RIDGE MAY CONTINUED TO PRODUCE ISOLATED
SHOWERS AND THUNDERSTORMS THROUGH THURSDAY NIGHT.

RIDGING BECOMES MORE DOMINANT BY FRIDAY MORNING. A FEW SHOWERS WILL
BE POSSIBLE OVER THE MOUNTAINS FRIDAY AFTERNOON...WITH THE REMAINDER
OF THE AREA REMAINING DRY. THE RIDGE AXIS WILL BE EAST OF THE
FORECAST AREA BY SATURDAY AFTERNOON...WITH SOUTHWEST FLOW DEVELOPING
OVER THE AREA.

PUSHES OF MOISTURE WILL BE FOUND WITHIN THE SOUTHWEST FLOW...HELPING
TO BRING AFTERNOON SHOWERS AND THUNDERSTORMS SUNDAY AND MONDAY. A
PERIOD OF DRY CONDITIONS RETURNS FOR THE MIDDLE PORTION OF THE WORK
WEEK. TEMPERATURES WILL REMAIN SLIGHTLY COOLER...WITH VALUES IN THE
LOW TO MID 80S FOR MUCH OF THE EXTENDED FORECAST PERIOD.

&&

.AVIATION.../06Z ISSUANCE/

VFR CONDITIONS WILL PREVAIL THROUGH THE PERIOD. ISOLATED SHOWERS
WILL OCCUR OVER THE SOUTHWEST AND WEST THROUGH 18Z. SCATTERED
SHOWERS AND STORMS WILL OCCUR OVER THE REGION WEDNESDAY AFTERNOON
AND NIGHT. LOCAL MVFR CONDITIONS MAY OCCUR AT TIMES DUE TO LOWERED
CIGS OR VSBYS. WIND GUSTS TO 30 KNOTS MAY OCCUR NEAR STORMS.
MOUNTAINS MAY BE PARTIALLY OBSCURED.

&&

.FIRE WEATHER...

ELEVATED FIRE DANGER ACROSS THE ENTIRE FORECAST AREA THROUGH
THIS EVENING AS WARM AND VERY DRY CONDITIONS CONTINUE ALONG WITH
ISOLATED GUSTY...MAINLY DRY THUNDERSTORMS.

VERY WARM TO HOT TEMPERATURES INTO THE EVENING WITH MINIMUM RH
VALUES INTO THE LOWER TO MID TEENS AND ISOLATED...MAINLY
MOUNTAIN...STORMS. WINDS WILL REMAIN RELATIVELY LIGHT AND TERRAIN
DRIVEN FOR NEARLY ALL ZONES EXCEPT THE FAR SOUTHWEST WHERE STORMS
OVER THE UINTAS WILL PRODUCE SOME GUSTY OUTFLOW WINDS LATER THIS
AFTERNOON. OTHERWISE...DEEP DRY INSTABILITY ACROSS THE CENTRAL AND
NORTHERN FORECAST AREA TODAY...WILL PUSH/KEEP HAINES VALUES BETWEEN
5 AND 6. ADDITIONALLY...THERE WILL BE ISOLATED MAINLY DRY
THUNDERSTORMS WITH GUSTY WINDS AROUND THROUGH THE EVENING. THEN...A
RATHER STRONG UPPER LEVEL DISTURBANCE AND DEVELOPING LEE SIDE LOW
PRESSURE SYSTEM...WITH INCREASING MOISTURE...WILL RAISE
PRECIPITATION CHANCES ACROSS THE FORECAST AREA ON
WEDNESDAY...BRINGING A REPRIEVE FROM THE HOT AND DRY CONDITIONS.

&&

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

&&

$$

SHORT TERM...PS
LONG TERM...BRANHAM
AVIATION...PS
FIRE WEATHER...PS


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