Area Forecast Discussion
Issued by NWS Grand Junction, CO

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
000
FXUS65 KGJT 011625
AFDGJT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND JUNCTION CO
1025 AM MDT SAT AUG 1 2015

.UPDATE...
ISSUED AT 933 AM MDT SAT AUG 1 2015

INCREASED SHOWERS/THUNDERSTORMS/CLOUDS OVER SOUTHEAST UTAH TODAY.
SHOWERS WITH A FEW EMBEDDED THUNDERSTORMS HAVE DEVELOPED FROM
AROUND MESA VERDE NP WESTWARD THIS MORNING...AND THE GRIDS WERE ON
THE DRY SIDE FOR THE LOWER ELEVATIONS. OTHERWISE EXCEPT FOR A
JUST FEW OTHER MINOR ADJUSTMENTS...THE FORECAST LOOKS ON TRACK.

&&

.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 350 AM MDT SAT AUG 1 2015

MOISTURE IS ON TRACK TO INCREASE THROUGHOUT THIS MORNING AS
TROPICAL MOISTURE SEEPS INTO EAST CENTRAL UTAH AND WEST CENTRAL
COLORADO FROM THE SOUTH. SATELLITE IMAGERY SHOWS A GOOD PLUME OF
CLOUD COVER HEADING TOWARD THE REGION THOUGH MANY OF THE HIGHER
CLOUD TOPS HAVE COLLAPSED OVERNIGHT. FORECAST MODELS INDICATE
PWATS NEAR OR ABOVE 1 INCH WILL REACH AS FAR NORTH AS THE TAVAPUTS
AND BOOKCLIFFS REGION BY MIDDAY TODAY. THE NAM SUGGESTS MODERATE
CAPE VALUES IN SE UTAH AND WEST CENTRAL COLORADO AROUND LATE
MORNING ORIENTED WITH THE H5 VORT MAX NEAR THE FOUR CORNERS THIS
MORNING. THIS WILL HELP TO PROVIDE EARLY CONVECTIVE DEVELOPMENT
TODAY...AS MANY IN THE REGION WILL SUSPECT WITH THE RISING
DEWPOINTS. NOT EXPECTING SHOWERS AND STORMS TO LAST TOO LONG WITH
PRACTICALLY NO VERTICAL SPEED SHEAR AT STEERING LEVELS...BUT
LIFTING IN CLEAR AREAS SHOULD BE GOOD TODAY.

DEEP MOISTURE WILL CONTINUE ITS NORTHWARD TRAJECTORY OVER THE NEXT
36 HOURS AND EVENTUALLY REACH THE WY/CO/UT BORDER. LIFTING DUE TO
A SLOW MOVING FEATURE WILL STRENGTHEN NEAR THE FOUR CORNERS AND
MOVE TO THE NORTH THIS AFTERNOON THROUGH SUNDAY EVENING. THIS
FEATURE WILL BRING A DECENT CHANCE OF PRECIPITATION TO MUCH OF THE
REGION...AND SHOWERS WHICH DO DEVELOP WILL BE AIDED BY WARM CLOUD
PROCESSES AND TEND TO BE LONG-LIVED AND MAINTAIN STRONG UPDRAFTS
ESPECIALLY ON SUNDAY. VERTICAL SHEAR DOES INCREASE AT THE LOWER
LEVELS ON SUNDAY WHICH SHOULD HELP PRECIPITATION TO STAY TOGETHER
FOR LONGER PERIODS OF TIME. ISOLATED FLASH FLOODING CONCERNS EXIST
FOR SUNDAY BUT STILL TRYING TO GAUGE WHETHER TIMING OF BEST STORMS
WILL BE DURING THE DAYTIME HEATING MAX.

.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 350 AM MDT SAT AUG 1 2015

UPPER LEVEL TROUGH WILL BE MOVING ACROSS THE CENTRAL ROCKIES
SUNDAY NIGHT...SLIDING EASTWARD ON MONDAY. THE DEEPEST MOISTURE
FOLLOWS THE MID LEVEL CIRCULATION...WHICH PLACES THE HIGHEST
PRECIPITABLE WATER VALUES OVER NW COLORADO SUNDAY NIGHT INTO
MONDAY. THIS WILL BE THE PRIMARY AREA FOR SHOWERS/STORMS WITH A
FEW HEAVY RAINERS DURING THIS TIME PERIOD. EXTENSIVE CLOUD COVER
KEEPS TEMPS SLIGHTLY ON THE COOL SIDE FOR EARLY AUGUST.

RIDGE AXIS RECOVERS ON TUESDAY THAT LEADS TO SOME STABILIZATION.
WEAK CONVECTIVE POTENTIAL DOES EXIST DURING THE PEAK HEATING HOURS
WITH A FEW STORMS OVER THE HIGHER TERRAIN. WEDNESDAY WILL BE
DRIER AS HIGH PRESSURE OVER ARIZONA AND NEW MEXICO TEMPORARILY
SHUTS DOWN THE MONSOONAL MOISTURE TAP INTO THE FOUR CORNER STATES.

A SHORT WAVE SKIRTS NRN COLORADO EARLY THURSDAY...BUT DOES NOT
APPEAR IT HAS THE DYNAMICAL FORCING OR MOISTURE TO KICK OFF ANY
SHOWERS.

THE GFS AND ECMWF SUGGEST THAT THE SUBTROPICAL HIGH CORE SHIFTS
TOWARD THE SRN PLAINS. MONSOONAL MOISTURE MAY SURGE NORTHWARD AND
RETURNS TO THE REGION BY NEXT FRIDAY.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1025 AM MDT SAT AUG 1 2015

SHOWERS AND THUNDERSTORMS OVER SW COLORADO AND SE UTAH WILL  THIS
MORNING WILL EXPAND NORTH THIS AFTERNOON...REACHING THE I-70
CORRIDOR. LOCAL +SHRA AND G30KTS WILL BE POSSIBLE WITH THE
STRONGEST CELLS. PASSING SHOWERS AND STORMS WILL RESULT IN ILS
CIGS FOR MOUNTAIN TAF SITES. AT TIMES MOUNTAINS WILL BE OBSCD.

SHRA/TSRA WILL BE SLOW WANE AFTER 02Z THIS EVENING. OVER THE SAN
JUAN/ABAJO MOUNTAINS AND SOUTH EXPECT SCATTERED SHOWERS TO LINGER
OVERNIGHT AND THROUGH SUN MORNING...WITH ISOLATED EMBEDDED
THUNDERSTORMS POSSIBLE.

NE UTAH AND A THE NW COLORADO CORNER WILL STAY DRY THROUGH THIS
FORECAST PERIOD.

&&

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

$$

UPDATE...EH
SHORT TERM...JAM
LONG TERM...PF
AVIATION...EH



USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.