Severe Thunderstorm Warning 31, NWS Grand Junction, CO

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND JUNCTION CO
220 PM MDT MON AUG 1 2005

.SHORT TERM (TONIGHT THROUGH WEDNESDAY)...
HIGH PRESSURE REMAINED OVER THE SOUTHEAST PLAINS OF COLORADO EARLY
THIS AFTERNOON. THUS...SUB-TROPICAL MOISTURE PLUME CONTINUED TO
SURGE NORTHWARD ACROSS UTAH...THEN EAST ACROSS NORTHERN COLORADO.
MOISTURE HAS CONTINUED TO SPREAD EAST AS EVIDENCED BY INCREASING
DEW POINT VALUES ACROSS THE CWFA. IN ADDITION...PW VALUES OVER
ONE INCH WERE PRESENT IN THE 12Z KGJT SOUNDING. MEANWHILE...CLOUD
SHIELD OVER AREAS OF DEEPEST MOISTURE HAS KEPT CONVECTION BACK WHEN
COMPARED TO YESTERDAY AT THIS TIME.

.TONIGHT: SHORTWAVE MOVING NORTHWARD INTO SOUTHERN UT EARLY THIS
AFTERNOON APPEARED WELL HANDLED BY THE NAM AND GFS. APPEARS THIS
FEATURE WILL BE MORE OF A PLAYER LATER TONIGHT THAN THIS EVENING AS
IT BEGINS TO SHIFT EAST LATE. CONSEQUENTLY...UPPED POPS ACROSS
EASTERN UTAH AND WESTERN COLORADO LATE TONIGHT AND EARLY TUESDAY.
OVERNIGHT LOWS WILL REMAIN MILD DUE TO CLOUD COVER AND INCREASED
LOWS FROM PREVIOUS FORECAST BASED ON HIGHER THAN EXPECTED LOWS
RECORDED THIS MORNING.

.TUESDAY: SHORTWAVE CONTINUES TO TRACK EASTWARD ACROSS THE CWFA AS
UPPER LEVEL TROF MOVES ACROSS THE NORTHERN TIER OF THE U.S.
FLATTENING THE HIGH PRESSURE RIDGE OVER THE AREA. EXPECT THIS FEATURE
WILL ENHANCE STORM DEVELOPMENT AND AREAL COVERAGE ON WEDNESDAY...
THOUGH MAINLY NORTH AS SOUTHERN ZONES SHOULD REMAIN A BIT DRIER BY
COMPARISON. AFTERNOON HIGHS WILL CONTINUE A DOWNWARD TREND AS IN
PREVIOUS FORECAST.

.TUESDAY NIGHT-WEDNESDAY: MORE OF THE SAME ON TAP AS SUB-TROPICAL
MOISTURE LINGERS OVER THE CWFA. THEREFORE...CONTINUED HIGH CHANCE
AND LIKELY POPS OVER THE MOUNTAINS DURING THE DAY WITH LOW END
CHANCE POPS IN THE VALLEYS AND DIURNAL DECREASE IN SHOWER/TSTM
ACTIVITY DURING THE NIGHT. AFTN HIGHS SHOULD CONTINUE TO TREND DOWN
WHILE EXPECT LOWS TO BE FAIRLY PERSISTENT AND A LITTLE ABOVE NORMAL
DUE TO CLOUD COVER.

.LONG TERM (WEDNESDAY NIGHT THROUGH MONDAY)...LATEST MONSOONAL BURST
WILL CONTINUE INTO THE BEGINNING OF THE WEEKEND...WITH SOME DRYING
AFTERWARDS.

SUBTROPICAL PLUME FROM WESTERN MEXICO WILL CONTINUE TO BE ADVECTED
IN THROUGH THE FIRST PART OF THE PERIOD. DEEP MOISTURE IS FORECAST
THROUGH AT LEAST LATE FRIDAY, ACCOMPANIED BY WEAK SHEAR ALOFT. THE
GFS PLACES THE CENTER OF HIGH PRESSURE OVER KANSAS BY THURSDAY...
WITH SOME RIDGING EXTENDING WESTWARD INTO THE GREAT BASIN. BY
FRIDAY 00Z...A WAVE EMBEDDED IN THE WESTERLY FLOW NORTH OF THE RIDGE
LOOKS TO PUT A DENT IN THE NORTHERN PART OF THE RIDGE, PROVIDING
SOME DECENT DYNAMICS FOR THE CWA (ESPECIALLY NORTH) ON FRIDAY AND
FRIDAY NIGHT.

DRYING AND SOME COOLER AIR BEHIND THIS SYSTEM WILL RESULT IN A
SLIGHTLY COOLER SATURDAY MORNING. HOWEVER, TEMPERATURES SHOULD
REBOUND QUICKLY AFTER THAT AS THE RIDGE BUILDS BACK UP. ENOUGH
RESIDUAL MOISTURE FOR HIGHER TERRAIN CONVECTION...BUT CHANCES
DIMINISH FOR THE LOWER VALLEYS FOR THE REMAINDER OF THE WEEKEND.

&&

.GJT WATCHES/WARNINGS/ADVISORIES...
.CO...NONE.
.UT...NONE.

&&

NL/BA

HAZARDOUS WEATHER OUTLOOK...CORRECTED
NATIONAL WEATHER SERVICE GRAND JUNCTION CO
837 AM MDT MON AUG 1 2005

CORRECTED TO INCLUDE ALL OF W CO AND E UT

COZ001>014-017>023-UTZ022>025-027>029-021300-
ANIMAS RIVER BASIN-ARCHES/GRAND FLAT-CANYONLANDS/NATURAL BRIDGES-
CENTRAL COLORADO RIVER BASIN-
CENTRAL GUNNISON AND UNCOMPAHGRE RIVER BASIN-
CENTRAL YAMPA RIVER BASIN-DEBEQUE TO SILT CORRIDOR-
EASTERN UINTA BASIN-EASTERN UINTA MOUNTAINS-
ELKHEAD AND PARK MOUNTAINS-FLAT TOPS-
FOUR CORNERS/UPPER DOLORES RIVER-
GORE AND ELK MOUNTAINS/CENTRAL MOUNTAINS-GRAND AND BATTLEMENT MESAS-
GRAND VALLEY-LA SAL AND ABAJO MOUNTAINS-LOWER YAMPA RIVER BASIN-
NORTHWEST SAN JUAN MOUNTAINS-PARADOX VALLEY/LOWER DOLORES RIVER-
ROAN AND TAVAPUTS PLATEAUS-SAN JUAN RIVER BASIN-SOUTHEAST UTAH-
SOUTHWEST SAN JUAN MOUNTAINS-TAVAPUTS PLATEAU-
UNCOMPAHGRE PLATEAU AND DALLAS DIVIDE-UPPER GUNNISON RIVER VALLEY-
UPPER YAMPA RIVER BASIN-WEST ELK AND SAWATCH MOUNTAINS-
837 AM MDT MON AUG 1 2005

THIS HAZARDOUS WEATHER OUTLOOK IS FOR EASTERN UTAH AND WESTERN
COLORADO.

.DAY ONE...TODAY AND TONIGHT...

SCATTERED SHOWERS AND THUNDERSTORMS...NUMEROUS IN NORTHEAST UTAH
MOUNTAINS...ARE POSSIBLE THIS AFTERNOON AND EVENING. HEAVY RAIN AND
LIGHTNING WILL BE THE MAIN HAZARDS ACCOMPANYING THESE STORMS. SOME
STORMS MAY PRODUCE FLOOD HAZARDS...ESPECIALLY IN AREAS THAT HAVE
RECEIVED HEAVY RAIN DURING THE PAST 24 HOURS.

.DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY...
SCATTERED SHOWERS AND THUNDERSTORMS ARE POSSIBLE EACH AFTERNOON AND
EVENING. LIGHTNING AND HEAVY RAIN MAY OCCUR WITH THESE THUNDERSTORMS.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS NOT ANTICIPATED TODAY OR TONIGHT.

CJC