Heavy Rain in Colorado, July 27, 2007

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND JUNCTION CO
153 PM MDT FRI JUL 27 2007

.SHORT TERM (TONIGHT THROUGH SUNDAY)...
SCATTERED SLOW MOVING THUNDERSTORMS ERUPTED ACROSS THE CWFA AROUND
MIDDAY AND WERE MOST NUMEROUS ACROSS THE NORTH IN RESPONSE TO AN
EASTWARD PROPAGATING SHORTWAVE. STORMS ACROSS THE REMAINDER OF THE
CWFA WERE ALMOST EXCLUSIVELY CONFINED TO THE HIGHER TERRAIN.

TONIGHT...EXPECT SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS TO
CONTINUE THROUGH SUNSET AND INTO THE LATE EVENING HOURS...ESPECIALLY
NORTH WHERE DYNAMIC LIFT PROVIDED BY SHORTWAVE WILL CONTINUE. HIGH
PRESSURE CENTER HAS SETTLED OVER THE FOUR CORNERS AREA WITH A BROAD
RIDGE STRETCHING FROM THE DESERT SOUTHWEST TO THE EASTERN CO
PLAINS. FLOW IS LIGHT BENEATH THE RIDGE WHILE PW VALUES ACROSS THE
REGION WERE ABOVE AN INCH. AS SUCH...SOME STORMS WILL BE CAPABLE OF
GENERATING HEAVY DOWNPOURS...THOUGH EXPECT FLOODING WILL BE
LOCALIZED.

SATURDAY-SUNDAY: DRYING TREND WILL BEGIN ACROSS THE NORTH IN RESPONSE
TO REPOSITIONING OF THE HIGH PRESSURE CIRCULATION OVER THE SOUTHWEST.
AS SUCH...DEEP SUB-TROPICAL MOISTURE WILL BE SHUNTED WEST OF THE AREA
AND DRIER AIR ACROSS THE NORTHERN INTERMOUNTAIN REGION WILL BEGIN TO
FLOW INTO THE REGION. CONSEQUENTLY...LOWERED POPS ACROSS THE NORTHERN
ZONES THIS WEEKEND...WHILE IN THE SOUTH WHERE MOISTURE WILL BE SLOWER
TO ERODE...CONTINUED WITH SCATTERED SHOWERS AND THUNDERSTORMS.

TEMPERATURES WILL RISE ACROSS THE NORTH AS MOISTURE DECREASES WHILE
LITTLE CHANGE IS EXPECTED ACROSS THE SOUTH. GUIDANCE NUMBERS LOOKED
REASONABLE...BUT FAVORED WARMER MAV GUIDANCE ON SUNDAY.

.LONG TERM (SUNDAY NIGHT THROUGH FRIDAY)...
SUNDAY NIGHT THROUGH TUESDAY...HIGH PRESSURE WILL BE CENTERED OVER
UTAH EARLY IN THE EXTENDED PERIOD.  THE NORTHWEST PORTION OF THE
FORECAST AREA WILL HAVE A TEMPORARILY LULL FROM THE SEASONAL
MONSOONAL MOISTURE...ALTHOUGH AFTERNOON INSTABILITY WILL STILL BE
PRESENT.  THE SOUTHWEST HALF WILL CONTINUE TO EXPERIENCE LONGER
LASING CONVECTIVE STORMS WITH A FEW OF THESE LASTING BEYOND
MIDNIGHT.

WEDNESDAY THROUGH FRIDAY...THE HIGH SHIFTS EAST AND APPEARS THE
NEXT SURGE OF MONSOONAL MOISTURE SPREADS ACROSS THE ENTIRE FORECAST
AREA.  THE GFS MODEL SHOWS 700 MB SPECIFIC MOISTURE TO BE HIGH AND
THAT THIS PERIOD WILL HAVE AN INCREASED THREAT OF HEAVY RAIN AND
FLASH FLOODING...ESPECIALLY FOR THE SRN HALF.

&&

.AVIATION...
SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS EXPECTED TO CONTINUE
THROUGH THIS EVENING. EXPECT REDEVELOPMENT ON FRIDAY...MAINLY DURING
THE AFTERNOON AND EVENING HOURS...THOUGH A DRYING WILL SET IN ACROSS
THE NORTH ON SATURDAY. VFR CONDITIONS SHOULD PREVAIL...ALTHOUGH SOME
STORMS WILL LIKELY PRODUCE MOUNTAIN OBSCURATIONS AND LOCAL MVFR
CONDITIONS IN HEAVY RAIN AND LOWERED CEILINGS.

&&

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

SHORT TERM...NL
LONG TERM...PF
AVIATION...NL

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE GRAND JUNCTION CO
545 AM MDT FRI JUL 27 2007

COZ001>014-017>023-UTZ022>025-027>029-281145-
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-
545 AM MDT FRI JUL 27 2007

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

.DAY ONE...TODAY AND TONIGHT

SCATTERED THUNDERSTORMS ARE EXPECTED TO DEVELOP AGAIN THIS
AFTERNOON AND CONTINUE THROUGH THE EVENING HOURS...BEFORE
DECREASING LATE TONIGHT. IN ADDITION TO DANGEROUS CLOUD TO GROUND
LIGHTNING...LOCALLY HEAVY RAINFALL AND SMALL HAIL WILL BE POSSIBLE.
HEAVY RAINFALL MAY CAUSE A FEW ARROYOS AND SMALL STREAMS TO QUICKLY
FILL OR RUN HIGH WITH FAST FLOWING WATER.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY

SCATTERED SHOWERS AND THUNDERSTORMS...MAINLY IN THE AFTERNOONS AND
EVENINGS...ARE EXPECTED TO CONTINUE THROUGH THE PERIOD. LIGHTNING AND
LOCALLY HEAVY RAINFALL CAN BE EXPECTED WITH THE STORMS.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS NOT ANTICIPATED TODAY OR TONIGHT.
HOWEVER...REPORTS TO THE NATIONAL WEATHER SERVICE OF HEAVY RAIN...
HAIL...AND ANY WEATHER RELATED DAMAGE WOULD BE GREATLY APPRECIATED.