Area Forecast Discussion
Issued by NWS Riverton, WY

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FXUS65 KRIW 011726
AFDRIW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RIVERTON WY
1126 AM MDT WED JUL 1 2015

.SHORT TERM...WEDNESDAY THROUGH FRIDAY NIGHT

THERE ARE STILL A COUPLE OF THUNDERSTORMS JUST WEST OF THE BORDER AT
THIS SECOND HOUR OF THE FIRST DAY OF THE SEVENTH MONTH. THESE SHOULD
BE OUT OF THE AREA BY 6 AM SO WE KEPT THE FORECAST FOR THE MORNING
DRY. HOWEVER...WE ARE NOT DONE WITH THE CONVECTION YET. THE FRONT
HAS SAGGED SOUTH OF THE AREA. BUT...THERE IS STILL A DECENT AMOUNT
OF MOISTURE AROUND WITH PRECIPITABLE WATER VALUES STILL OVER AN INCH
IN SOME AREAS. NOT AS HIGH AS YESTERDAY...BUT STILL ABOVE NORMAL. IN
ADDITION...WE WILL STILL BE NEAR THE EDGE OF THE RIDGE WHICH WILL
ALLOW SOME JET STREAKS TO RIDE NEAR THE AREA. DURING THE AFTERNOON
AND EVENING...WE WILL BE IN THE RIGHT REAR QUAD OF ONE OF THOSE
STREAKS. AS A RESULT...EXPECT MORE SHOWERS AND
THUNDERSTORMS...ESPECIALLY EAST OF THE DIVIDE. ONCE AGAIN...THE
EASTERN PORTION OF THE AREA IS IN THE MARGINAL RISK AREA SO WE WILL
INCLUDE THE UBIQUITOUS SMALL HAIL AND GUSTY WIND WORDING.
TEMPERATURES SHOULD BE A COUPLE OF DEGREES COOLER BUT STILL ABOVE
NORMAL. THE GFS IS STILL SHOWING A POSSIBLE MCS BRUSHING JOHNSON
COUNTY TONIGHT SO WE MAINTAINED THE ISOLATED WORDING FOR TONIGHT.

THURSDAY STILL LOOKS TO BE A BIT LESS ACTIVE AS FAR AS THUNDERSTORMS
ARE CONCERNED. TEMPERATURES ALSO LOOK TO BE A FEW DEGREES COOLER AS
WELL. WITH PRECIPITABLE WATER VALUES FALLING BACK DOWN TOWARD NORMAL
LEVELS AND WEAKER JET DYNAMICS...CONVECTION SHOULD BE LIMITED TO THE
OROGRAPHIC VARIETY. IN ADDITION...WITH WEAK STEERING FLOW THERE
SHOULD BE LITTLE CHANCE OF THE SHOWERS AND STORMS TO MOVE OFF OF THE
MOUNTAINS.

AS WE HEAD INTO FRIDAY THE RIDGE WILL BEGIN TO BUILD BACK OVER THE
AREA AND WARM THINGS UP ONCE AGAIN WITH 90S ONCE AGAIN APPEARING IN
MANY OF THE VALLEY LOCATIONS. WE DID MAKE A CHANGE TO THE FORECAST
HERE HOWEVER. WITH SOME INCREASE IN MOISTURE AND MORE CAPE...WE
ADDED SOME ISOLATED POPS IN SOME AREAS DOWNWIND OF THE MOUNTAINS. WE
DID NOT GO ALL THE WAY LIKE A FEW OF THE MODELS HAVE DEPICTED BUT IT
WILL BE SOMETHING TO WATCH.

.LONG TERM...SATURDAY THROUGH WEDNESDAY

A MAINLY HOT AND DRY DAY IS EXPECTED FOR THE FOUR OF JULY...AS
700 MB TEMPERATURES RANGE BETWEEN 15C AND 20C. THE STRONG
INSOLATION MIGHT BE ENOUGH FOR A FEW LATE DAY THUNDERSTORMS OVER
THE HIGHER TERRAIN PUSHING SE INTO THE LOWER ELEVATIONS. HOWEVER
THE LIMITED MOISTURE /~0.50 PRECIPITABLE WATER/ AND NO
DISCERNIBLE WAVE IN THE FLOW SHOULD KEEP CONVECTION VERY
LIMITED...KEEPING FOUR OF JULY PLANS ON SCHEDULE.

MEDIUM RANGE MODELS HAVE TRENDED WITH A STRONGER SUMMER COLD FRONT
SWEEPING ACROSS THE FORECAST AREA SUNDAY...ASSOCIATED WITH A
TROUGH PUSHING ACROSS THE CANADIAN PRAIRIE PROVINCES THIS WEEKEND.
AT THE SAME TIME...THE SUBTROPICAL RIDGE BECOMES CENTERED ACROSS
THE SOUTHERN ROCKIES/NORTHERN MEXICO AREA. ALTHOUGH SOME MONSOONAL
MOISTURE COULD STILL WORK INTO THE SOUTHERN AREA SUNDAY AND
MONDAY...THE MAIN INFLUENCE WILL BE FROM THIS COLD FRONT AND
POSSIBLY SOME RIGHT ENTRANCE REGION OF AN UPPER JET. MODELS ARE
HITTING SUNDAY NIGHT AND MONDAY THE HARDEST WITH PRECIPITATION
RIGHT NOW IN A POST-FRONTAL ENVIRONMENT. MODELS ARE ALSO PRETTY
STABLE IN WAKE OF THE FRONT ESPECIALLY EAST OF THE DIVIDE...WITH
MEAGER LAPSE RATES AND GENERALLY POSITIVE LIFTED INDICES. HAVE
INCREASED POPS SLIGHTLY AND LOWERED TEMPS FOR SUNDAY AND
MONDAY...WITH PLENTY OF TIME TO HIT THINGS HARDER IF MODELS
CONTINUE THE TREND OF A STRONGER COLD FRONT. MODELS SHOW A 1024 MB
HIGH BUILDING INTO THE NORTHERN ROCKIES SUNDAY NIGHT WHICH IS A
STRONG SFC HIGH FOR EARLY JULY.

MEDIUM RANGE MODELS THEN DIVERGE IF RIDGING OR IF A MORE ZONAL
FLOW WILL PREVAIL MIDDLE OF NEXT WEEK. REGARDLESS A WARMING TREND
IS EXPECTED TUESDAY AS THE SFC FRONT LIFTS BACK NORTHWARD...BUT A
CONTINUED DAILY ISOLATED TO LOCALLY SCATTERED CONVECTION WILL
PREVAIL.

&&

.AVIATION.../18Z ISSUANCE/

GENERALLY CLEAR CONDITIONS WILL GIVE AWAY A BIT THIS
AFTERNOON...WITH SOME DEVELOPING SHOWERS AND THUNDERSTORMS. MOST
ACTIVITY WOULD BE PRESENT OVER TERMINALS EAST OF THE CONTINENTAL
DIVIDE...WITH TERMINALS WEST OF THE LINE REMAINING GENERALLY VFR
CONDITIONS. THUNDERSTORMS MAY PRODUCE PERIODS OF MVFR CONDITIONS
WITH RAIN...AND MAY BRING INSTANCES OF GUSTY AND ERRATIC WIND.
IMPACTED TERMINALS HAVE HAD VCTS INCLUDED IN THEIR FORECAST. THE
HIGHER TERRAINS WILL ALSO CONTINUE TO SEE SHOWER AND THUNDERSTORM
ACTIVITY WHICH MAY INCREASE THEIR TURBULENCE ACTIVITY THIS
AFTERNOON AND INTO THE EVENING. CLEARING CONDITIONS EXPECTED AFTER
04Z THIS EVENING WITH WIDESPREAD VFR CONDITIONS EXPECTED THROUGH
THE REMAINDER OF THE PERIOD.

&&

.FIRE WEATHER...

TEMPERATURES WILL BE A COUPLE OF DEGREES COOLER AND RELATIVE
HUMIDITY A BIT HIGHER THAN YESTERDAY FOR MOST AREAS. HOWEVER...FIRE
DANGER MAY BE ELEVATED AT TIMES WITH ANOTHER CHANCE OF AFTERNOON AND
EVENING THUNDERSTORMS THAT MAY BRING GUSTY WINDS AND LIGHTNING
STRIKES. EXPECT COOLER TEMPERATURES AND MAINLY DRY CONDITIONS FOR
THURSDAY BEFORE ANOTHER WARM UP FOR THE FOURTH OF JULY WEEKEND.

&&

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

$$

SHORT TERM...HATTINGS
LONG TERM...WM
AVIATION...BRANHAM
FIRE WEATHER...HATTINGS


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