Area Forecast Discussion
Issued by NWS Grand Junction, CO

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FXUS65 KGJT 061036
AFDGJT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND JUNCTION CO
436 AM MDT FRI MAY 6 2016

.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 436 AM MDT FRI MAY 6 2016

LARGE CLOSED LOW MOVING ONSHORE THE WESTERN US TODAY WILL SLOWLY
MOVE EASTWARD OVER THE NEXT FEW DAYS. TODAY...STRONG LARGE SCALE
ASCENT WILL BE DRIVING THUNDERSTORM DEVELOPMENT FROM SOUTH TO
NORTH. ALREADY THIS MORNING THE CLOUD TOPS HAVE BEEN INCREASING
FAIRLY DRAMATICALLY FROM NORTHERN ARIZONA INTO UTAH. THIS AREA OF
ENHANCING PRECIPITATION WILL SHIFT EAST TODAY AND BRING SCATTERED
SHOWERS AND THUNDERSTORMS TO EASTERN UTAH AND WESTERN COLORADO FOR
MUCH OF TODAY. SOME STORMS MAY NEAR OR POTENTIALLY EXCEED SEVERE
THUNDERSTORM CRITERIA TODAY...WITH WIND BEING THE LARGEST THREAT.
WIND GUSTS MAY EXCEED 58 MPH IN THE STRONGEST STORMS AND HAIL UP
TO ONE INCH IS POSSIBLE...THOUGH LESS LIKELY THAN REACHING THE
STRONG WIND GUSTS. THE RAP FORECAST MODEL INDICATES DAYTIME
HEATING WILL OVERCOME CONVECTIVE INHIBITION ACROSS NE UTAH AROUND
NOON AND ACROSS WESTERN COLORADO SHORTLY THEREAFTER. FORECAST CAPE
VALUES EXCEED 1000 J/KG THIS AFTERNOON...INDICATING A PEAK OF
CONVECTIVE ACTIVITY AROUND 4 TO 8PM ACROSS NE UTAH AND NW COLORADO.
THERE WILL BE A LOT OF VIRGA AROUND TODAY WHICH WILL HELP TO KEEP
CONDITIONS BREEZY THROUGHOUT THE DAY WITH OR WITHOUT RAIN NEARBY.

.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 436 AM MDT FRI MAY 6 2016

THE DETAILS OF THIS SLOW MOVING SYSTEM CONTINUE TO EVOLVE. IT
LOOKS LIKE THERE WILL BE AT LEAST A COUPLE OF ROBUST CIRCULATIONS
THAT WILL TRACK ACROSS THE AREA SAT AND SUN. THROUGH THE
WEEKEND...LOOK FOR ENHANCED SHOWERS AND THUNDERSTORMS AS EACH
CIRCULATION PASSES. POPS GENERALLY SHOW A BROAD-BRUSHED FORECAST
WITH CHANCE TO LIKELY POPS...MAINLY IN THE MOUNTAINS.
AFTERNOONS/EARLY EVENINGS WILL SHOW AN UPTICK IN CONVECTION
INCLUDING THUNDERSTORMS DUE TO THE DIURNAL ASSIST. SNOW LEVELS
WILL REMAIN HIGH AS THIS SYSTEM IS QUITE MILD. ACCUMULATING SNOW
WILL GENERALLY BE AT OR ABOVE 10K-11K FEET. BUT CONVECTION WILL
CERTAINLY DRIVE SNOW...GRAUPEL OR SNOW PELLETS LOWER AT TIMES.

DID BUMP UP POPS OVER THE NEXT FEW DAYS DURING TIME PERIODS WHERE
I WAS MORE CONFIDENT IN PRECIPITATION OCCURRING...WITH THE BIGGEST
INCREASE LATE SUNDAY NIGHT. AVAILABLE MOISTURE SIGNIFICANTLY
INCREASES LATE SUNDAY AND MONDAY AND THE CLOSED LOW WRAPS STRONG
ENERGY COUNTERCLOCKWISE INTO THE WESTERN SLOPE OF COLORADO.
EXACT SET-UP LOCATION OF THIS WRAP-AROUND WILL HAVE TO BE
DIAGNOSED IN LATER FORECASTS...BUT CONFIDENCE IS THERE FOR AN
UPTICK IN PRECIPITATION COVERAGE SUNDAY NIGHT INTO EARLY MONDAY.

WITH LESS CONFIDENCE...MODELS INDICATE ANOTHER SEPARATE
DISTURBANCE WILL BRUSH THE NORTH DURING THE TUE- WED TIME FRAME AS
A TROUGH PASSES ACROSS THE NORTHERN ROCKIES AND INTO THE NORTHERN
PLAINS. THE IMPACTS FROM THIS NEXT SYSTEM LOOK PRETTY LOW AT THIS
TIME.

A COOLING TREND WILL CONTINUE THROUGH SUNDAY. THE TREND WILL THEN
REVERSE FOR A SLOW WARMUP THROUGH THE NEW WORK WEEK.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 436 AM MDT FRI MAY 6 2016

THE MORNING IS ALREADY STARTING OFF EXCITING WITH STORMS HAVING
INITIATED BEFORE 10Z. INITIATION OF STORMS WILL CONTINUE AS LARGE
SCALE ASCENT DRAMATICALLY INCREASES TODAY. GUSTY WINDS TO 60 MPH
WILL BE THE LARGEST THREAT TODAY WITH THUNDERSTORMS...BUT THIS IS
NOT EXPECTED UNTIL AFTER 18Z AND WILL BE VERY ISOLATED IN NATURE
IF AT ALL. CONDITIONS WILL STAY GENERALLY BREEZY TODAY. HEAVY
PRECIPITATION IS NOT EXPECTED AT THIS TIME...SO CIGS AND VIS WILL
REMAIN VFR THROUGH MOST OF THE DAY.

&&

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

$$

SHORT TERM...JAM
LONG TERM...EH/JAM
AVIATION...JAM



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