Area Forecast Discussion
Issued by NWS Riverton, WY

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000
FXUS65 KRIW 111736 AAA
AFDRIW

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE RIVERTON WY
1136 AM MDT FRI JUL 11 2014

.SHORT TERM...TODAY THROUGH SUNDAY NIGHT

WEAK SHOWERS ACROSS SOUTHERN WYOMING WILL CONTINUE...WITH ADDITIONAL
ACTIVITY DEVELOPING OVER WESTERN WYOMING THIS MORNING. A DISTURBANCE
WILL MOVE THROUGH THE STATE THIS AFTERNOON. THIS DISTURBANCE WILL
USHER IN ADDITIONAL MOISTURE AND INSTABILITY TO POTENTIALLY GENERATE
WIDESPREAD SHOWER AND THUNDERSTORM ACTIVITY. THERE MAY BE SOME
ISOLATED STRONGER STORMS ACROSS JOHNSON COUNTY THIS AFTERNOON. GUSTY
WIND AND SMALL HAIL WILL BE POSSIBLE WITH ALL ACTIVITY TODAY.

A BUILDING TRANSITORY RIDGE WILL DEVELOP SATURDAY MORNING WEST OF
THE FORECAST AREA. THIS WILL INCREASE THE NORTHWEST FLOW OVER THE
AREA...AND POTENTIALLY USHER IN ANOTHER ROUND OF AFTERNOON SHOWERS
AND THUNDERSTORMS. OVERALL...COVERAGE ON SATURDAY IS NOT EXPECTED TO
ENCOMPASS AS MUCH OF THE STATE AS TODAY...BUT ACTIVITY OVER THE WEST
AND NORTH WILL CERTAINLY BE POSSIBLE.

A SIMILAR SCENARIO EXPECTED ON SUNDAY...WITH AFTERNOON SHOWERS AND
THUNDERSTORMS EXPECTED. THE POTENTIAL WILL MOVE EAST...WITH MOST OF
THE THREAT BEING REALIZED ACROSS EASTERN WYOMING. THE RIDGE OF HIGH
PRESSURE LOOKS TO REACH ITS AMPLIFICATION MAXIMUM LATE SUNDAY
NIGHT...WITH THE RIDGE RELAXING THROUGH THE OVERNIGHT HOURS.

.LONG TERM...MONDAY THROUGH FRIDAY

ON MONDAY...A STRONG COLD FRONT FOR JULY WILL BE PUSHING ACROSS THE
FORECAST AREA...IN RESPONSE TO AN ANOMALOUS UPPER LOW OVER THE UPPER
MIDWEST. THIS UPPER LOW HAS 500 MB HEIGHTS ABOUT 3 STANDARD
DEVIATIONS LOWER THAN WHAT SHOULD BE EXPECTED THIS TIME OF YEAR.
THIS COLD FRONT WILL BE UNDERCUTTING A STRONG SUBTROPICAL RIDGE
CENTERED OVER THE GREAT BASIN. ALTHOUGH THERE WILL BE A STRONG COLD
FRONT OVER THE AREA...THE BEST DYNAMICS WITH THE UPPER LOW/FRONTAL
BOUNDARY WILL BE WELL SOUTHEAST OF THE AREA. THE BEST SHOT AT
CONVECTION...MAINLY ISOLATED...MONDAY WILL BE ACROSS THE CENTRAL
AND SOUTHWEST SECTIONS WITH PROBABLY A STABLE AND COOL ENVIRONMENT
ACROSS THE NORTHEAST SECTIONS OF THE AREA.

GLOBAL MODELS CONTINUE TO SHOW A WEAK SHORTWAVE OVER THE PACIFIC
NORTHWEST PUSHING UP AND OVER THE SUBTROPICAL RIDGE MONDAY INTO N
ID/NW MT. MODELS THEN SHOW THIS SHORTWAVE SLIDING SOUTHEAST ACROSS
THE COWBOY STATE IN THE TUESDAY/WEDNESDAY TIME FRAME. MODELS HAVE
GENERALLY TRENDED SLOWER WITH MORE IMPACTS FARTHER EAST...THAN WHAT
THEY WERE ADVERTISING ON YESTERDAYS 00Z RUNS. WILL HAVE SLIGHT TO
CHANCE POPS FOR TUESDAY...AND HAVE SLIGHT POPS EVERYWHERE FOR
WEDNESDAY TO RESPECT THE SLOWER SOLUTIONS.

FOR THURSDAY AND FRIDAY...MODELS GENERALLY SHOW LOW AMPLITUDE
RIDGING BECOMING THE DOMINATE FEATURE OVER THE FORECAST AREA...AHEAD
OF A TROUGH PERHAPS DIGGING INTO THE PACIFIC NORTHWEST FRIDAY.
ISOLATED CONVECTION WILL REMAIN POSSIBLE...MAINLY OVER THE MOUNTAINS
AND ADJACENT LOWER ELEVATIONS.

TEMPERATURES WILL GENERALLY BELOW AVERAGE EAST OF THE DIVIDE THROUGH
WEDNESDAY...ESPECIALLY MONDAY AND TUESDAY WHEN HIGH TEMPS ARE
EXPECTED TO BE 8 TO 15 DEGREES BELOW NORMAL. A RETURN TO SEASONAL TO
SLIGHTLY ABOVE AVERAGE TEMPS ARE EXPECTED THURSDAY AND FRIDAY.

SEASONAL TEMPERATURES ARE EXPECTED WEST OF THE DIVIDE THROUGH
WEDNESDAY...WITH A RETURN TO ABOVE AVERAGE TEMPS THURSDAY AND FRIDAY.

.AVIATION.../18Z ISSUANCE/

SCATTERED SHOWERS AND THUNDERSTORMS THROUGH 03Z SAT...TAPERING OFF
TO ISOLATED THROUGH 09Z. MAINLY VFR CONDITIONS BUT THERE WILL BE
OCCASIONAL MVFR VISIBILITIES ASSOCIATED WITH THE STRONGEST RAIN
SHOWERS AND THUNDERSTORMS THIS AFTERNOON. A RICH MOISTURE FEED
COMBINED WITH SEVERAL EMBEDDED SHORTWAVES WILL DRIVE SCATTERED TO
OCCAIONALLY WIDESPREAD SHOWERS AND THUNDERSTORMS THIS AFTERNOON.
MOST LIKELY AREAS FOR HEAVY RAIN PRODUCING STORMS WILL LAY SOUTH
AND EAST OF A LINE FROM KEVW TO KBYG. STEERING FLOW EXPECTED TO
ONLY BE AROUND 10KTS...SO MAIN HAZARD WILL BE HEAVY RAIN. LOW-
LEVEL BOUNDARY WILL PUSH TO AROUND NORTHERN SWEETWATER COUNTY THIS
AFTERNOON SETTING THE STAGE FOR WEAK CONVERGENCE. THIS SHOULD AID
CONVECTION IN SWEETWATER COUNTY AND THEN DOWNSTREAM TO NATRONA AS
THE STORMS TRACK ENE. KEPT +VCTS IN KRKS AND KCPR FORECAST...WHILE
KRIW AND KWRL ARE LEAST LIKELY TERMINALS TO BE IMPACTED. AT LEAST
PARTIAL CLEARING ANTICIPATED AFTER 08Z/SATURDAY. IF RAIN FALLS AT
KCPR AND CLEARING IS SUFFICIENT WOULD NOT BE SURPRISED TO SEE
PATCHY FOG IN WEAK EASTERLY FLOW TOWARD SUNRISE SATURDAY.

.FIRE WEATHER...

ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE
ACROSS THE FORECAST AREA TODAY. DEVELOPMENT LOOKS MOST FAVORABLE
ACROSS NORTHEASTERN WYOMING. ANY STORM DEVELOPMENT MAY CONTAIN SMALL
HAIL AND GUSTY WIND. TEMPERATURES ACROSS SOUTHERN WYOMING WILL COOL
TODAY...WITH WARMING TEMPERATURES ANTICIPATED OTHERWISE. CONTINUED
AFTERNOON SHOWERS AND THUNDERSTORMS WILL BE FOUND THROUGH THE NEXT
COUPLE DAYS. A GENERAL WARMING TREND WILL BE FOUND OVER THE AREA
WITH SLIGHTLY LOWERING DAYTIME HUMIDITY.

&&

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

$$

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





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