597 FXUS65 KRIW 110537 AFDRIW AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE RIVERTON WY 1137 PM MDT WED JUL 10 2013 .SHORT TERM...TONIGHT THROUGH THURSDAY THERE WILL BE ISOLATED THUNDERSTORMS POSSIBLE OVER AND NEAR THE MOUNTAINS EARLY THIS EVENING. TONIGHT WILL BE VERY MILD. THURSDAY SOUTHWEST WINDS WILL INCREASE ACROSS SOUTHWEST AND CENTRAL WYOMING. ISOLATED AFTERNOON THUNDERSTORMS WILL ALSO BE POSSIBLE OVER AND NEAR THE MOUNTAINS. TEMPERATURES WILL BE HOT WITH SOME RECORD HIGHS POSSIBLE. MANY AREAS IN THE LOWER ELEVATIONS WILL BE AROUND 100. .LONG TERM...THURSDAY NIGHT THROUGH WEDNESDAY WEAK SURGE OF MOISTURE INTO THE FAR WEST AND SOUTH WILL KEEP A FEW GUSTY STORMS INTO THE EVENING. WEAK EMBEDDED DISTURBANCE MAY BE STRONG ENOUGH TO PUSH A COLD FRONT EAST OF THE DIVIDE WITH GUSTY NW WINDS ACROSS THE WIND RIVER BASIN DURING THE EVENING. ANOTHER LITTLE BETTER SURGE OCCURS OVERNIGHT THURSDAY NIGHT WITH HIGHER PW AIR MOVING INTO THE AREA BUT STILL WARM ALOFT FOR LIMITED CAPE...MAINLY MOUNTAINS AND SOUTH FOR FRIDAY. WARM NIGHT THURSDAY NIGHT WITH A LESS HOT DAY FRIDAY BUT WITH MORE HUMIDITY. HEIGHTS RISE AGAIN FRIDAY NIGHT INTO SATURDAY WITH LIMITED MONSOONAL MOISTURE HANGING AROUND THE AREA. LIMITED CAPE AGAIN SO ISOLATED STORMS AT BEST WITH CONTINUED WARM MID LEVEL TEMPERATURES. LITTLE CHANGE ON SUNDAY BUT THEN CONDITIONS BEGIN TO CHANGE SIGNIFICANTLY MONDAY THROUGH WEDNESDAY OF NEXT WEEK. POSSIBLE SHORTWAVE PASSING THROUGH THE NRN HIGH PLAINS PUSHES A COLD FRONT INTO THE ERN ZONES MONDAY WITH A VERY MOIST ELY RETURN FLOW INTO OUR ERN ZONES SETTING THE STAGE FOR POTENTIAL SEVERE THUNDERSTORMS IN JOHNSON AND POTENTIALLY NATRONA MONDAY AFTERNOON AND EVENING. THE BIGGER CHANGE COULD OCCUR TUESDAY INTO WEDNESDAY WITH A SIGNIFICANT SURGE OF MONSOONAL MOISTURE AS THE UPPER HIGH RETREATS WWD ALLOWING FOR A FAVORABLE SLY FLOW TO BRING INCREASING MOISTURE TO ALL OF OUR AREA FROM TUESDAY ONWARD. && .AVIATION.../06Z ISSUANCE/ EAST OF THE DIVIDE...KCOD/KCPR/KLND/KRIW/KWRL ROUTES A STORM SYSTEM APPROACHING THE REGION...AND SOME HIGH LEVEL MONSOONAL MOISTURE SURGING NORTHWARD WILL RESULT IN INCREASING HIGH/MID LEVEL CLOUDINESS THURSDAY MORNING. CONSIDERABLE HIGH CLOUDINESS IS EXPECTED THURSDAY AFTERNOON WITH CEILINGS RANGING BETWEEN 18 AND 30 KFT MSL. WARM AIR ALOFT AND DRY AIR AT THE SURFACE WILL KEEP THE ATMOSPHERE RELATIVELY STABLE THURSDAY. THIS WILL LIMIT COVERAGE AND STRENGTH OF ANY CONVECTION. WILL KEEP TAF SITES DRY THROUGH THE FORECAST PERIOD...BUT WOULD NOT BE SURPRISED TO SEE SOME CONVECTION AFFECT KCPR AND KCOD TAF SITES LATE IN THE AFTERNOON INTO THURSDAY NIGHT. THE MAIN HAZARD WOULD BE STRONG...ERRATIC WINDS...DUE TO VERY DRY AIR AT THE SURFACE. ALSO...A LEE SURFACE TROUGH IN COMBINATION WITH INCREASING SOUTHWEST FLOW ALOFT WILL RESULT IN BREEZY SOUTHWEST TO WEST WINDS...MAINLY FROM KRKS-KCPR THURSDAY AFTERNOON. A COLD FRONT WILL PUSH SOUTHEAST ACROSS THE REGION LATE THURSDAY AFTERNOON...AND SHOULD BE THROUGH THE ENTIRE AREA BY 06Z FRIDAY. THE MAIN EFFECT WILL BE TO SHIFT WINDS TO THE NORTHWEST AND NORTH...AND BE A BIT GUSTY FOR 2 TO 4 HOURS. DEEPER MONSOONAL MOISTURE TO ADVECT INTO THE AREA LATE THURSDAY NIGHT WHICH COULD ALLOW FOR SOME LATE NIGHT -SHRA ACTIVITY...BUT CONFIDENCE IS NOT HIGH ENOUGH TO INSERT THIS POSSIBLITY INTO AREA TAF SITES. WEST OF THE DIVIDE...KBPI/KJAC/KPNA/KRKS ROUTES A STORM SYSTEM APPROACHING THE REGION...AND SOME HIGH LEVEL MONSOONAL MOISTURE SURGING NORTHWARD WILL RESULT IN INCREASING HIGH/MID LEVEL CLOUDINESS THURSDAY MORNING. CONSIDERABLE MID/HIGH LEVEL CLOUDINESS IS EXPECTED THURSDAY AFTERNOON...WITH CEILINGS RANGING BETWEEN 15 AND 25 KFT MSL IN THE AFTERNOON. THE LOWER CEILINGS ARE EXPECTED TO BE ACROSS NORTHWEST WYOMING. A LEE SURFACE TROUGH DEVELOPING IN RESPONSE TO THIS STORM SYSTEM WILL RESULT IN BREEZY WEST/SOUTHWEST WINDS ESPECIALLY ACROSS SWEETWATER COUNTY THIS AFTERNOON. THE ASSOCIATED...MAINLY DRY COLD FRONT WITH THIS STORM SYSTEM IS EXPECTED TO PUSH EAST/SOUTHEAST ACROSS THE AREA LATE THURSDAY AFTERNOON AND EVENING...RESULTING IN BREEZY TO WINDY WEST/NORTHWEST WINDS. WINDS WILL WEAKEN AFTER 06Z FRIDAY. DESPITE THE INCREASE IN MID LEVEL MOISTURE...WARM AIR ALOFT AND RELATIVELY DRY AIR AT THE SURFACE WILL KEEP THE ATMOSPHERE RELATIVELY STABLE THURSDAY LIMITING COVERAGE AND STRENGTH OF CONVECTION THIS AFTERNOON AND OVERNIGHT. THE BEST CHANCE FOR CONVECTION APPEARS TO BE AFTER 00Z FRIDAY WITH SOME -SHRA ACTIVITY LASTING WELL PAST MIDNIGHT...AS DEEPER MONSOONAL MOISTURE IS PULLED NORTHWARD. && .FIRE WEATHER... ISOLATED THUNDERSTORMS WILL BE POSSIBLE OVER AND NEAR THE MOUNTAINS EARLY THIS EVENING. TONIGHT WILL BE MILD AND DRY. THURSDAY WILL BECOME BREEZY TO WINDY BY NOON WITH VERY LOW RELATIVE HUMIDITY AND HOT TEMPERATURES. A FIRE WEATHER WATCH HAS BEEN ISSUED FOR FIRE WEATHER ZONES 277...279...280...281...283...285 AND 288 FROM NOON UNTIL 9 PM MDT THURSDAY. ISOLATED MOUNTAIN THUNDERSTORMS ARE EXPECTED IN THE AFTERNOON AND EARLY EVENING AS WELL. TEMPERATURES WILL COOL ON FRIDAY WITH INCREASED CLOUD COVER...AND MORE SHOWERS AND THUNDERSTORMS EXPECTED. && .RIW WATCHES/WARNINGS/ADVISORIES... FIRE WEATHER WATCH FROM THURSDAY AFTERNOON THROUGH THURSDAY EVENING WYZ277-279>281-283-285-288. && $$ SHORT TERM...C.BAKER LONG TERM...SKRBAC AVIATION...WM FIRE WEATHER...C.BAKER