000
FXUS65 KGJT 180915
AFDGJT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND JUNCTION CO
315 AM MDT SAT MAY 18 2013

.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 314 AM MDT SAT MAY 18 2013

LIGHT SHOWERS QUICKLY DEVELOPING ACROSS EASTERN UTAH AND EXTREME
WESTERN COLORADO THIS MORNING IN DIFLUENT PATTERN OUT AHEAD OF
THE NEXT SHRTWV AND ASSOCIATED SFC FRONT. THIS SYSTEM WILL
PROGRESS SLOWLY EAST THROUGH THE FORECAST AREA TODAY...WITH
SHOWERS AND THUNDERSTORMS BECOMING FAIRLY WIDESPREAD BY THIS
AFTERNOON. HAVE BOOSTED POPS CONSIDERABLE ACROSS THE BOARD AND
ADJUSTED TIMING TO FIT WITH THE LATEST SHORT TERM MODELS. LOW
LEVELS WILL TAKE A BIT TO SATURATE...SO EARLY SHOWERS WILL BE A
BIT GUSTY...BUT EFFICIENT RAIN PRODUCERS WITH PRECIPITABLE WATER
VALUES IN EXCESS OF 0.50 INCH. SNOW LEVELS LOOK TO BE AROUND 10K
TODAY...ALTHOUGH CONVECTION WILL DRIVE IT DOWN TO NEAR THE 9K
LEVEL AT TIMES. NO SIGNIFICANT DAYTIME ACCUMULATIONS ANTICIPATED.
TEMPERATURES WILL BE MUCH COOLER TODAY WITH CLOUD COVER AND
FRONTAL PASSAGE EXPECTED THIS AFTERNOON.

UPPER LEVEL TROUGH PASSAGE OCCURS TONIGHT WITH THE 85KT JET CURVED
SOUTH OF THE FOUR CORNERS. WEAK COLD ADVECTION...CYCLONIC
FLOW...AND NW SLOPE OROGRAPHICS ALL INDICATE SHOWERS WILL CONTINUE
MAINLY OVER THE NORTH AND INTO THE CENTRAL MOUNTAINS. SNOW LEVELS
DROP TO AROUND 7500FT NORTH TO 10000FT SOUTH WITH 1-3 INCH
ACCUMULATIONS POSSIBLE OVER THE NORTHERN MTNS.

NW FLOW CONTINUES THROUGH MONDAY NIGHT BRINGING A COOL AND UNSETTLED
PERIOD. SUNDAY A SECOND OPEN WAVE DROPS THROUGH THE GREAT BASIN.
THIS BUILDS A BRIEF RIDGE OVER THE REGION THAT WILL DIMINISH POPS
BUT AFTERNOON CONVECTIVE SHOWERS REMAIN POSSIBLE. SNOW LEVELS RISE
TO ABOVE 10KFT MELTING MUCH OF THE SNOW THAT FELL IN THE HIGH
COUNTRY THE NIGHT BEFORE.

.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 314 AM MDT SAT MAY 18 2013

SUNDAY NIGHT-MONDAY...THE SECOND WAVE WORKS ACROSS THE REGION EARLY
MONDAY WITH THE BEST QG FORCING PROGGED TO PASS THROUGH THE SOUTHERN
PORTION OF THE FORECAST AREA. DIVERGENCE ALOFT IS CENTERED OVER THE
NORTH THROUGH THE AFTERNOON THAT MAY PROVIDE MORE CONVECTIVE
POTENTIAL. SNOW LEVELS LOWER TO AROUND 8KFT OVERNIGHT BUT RISE CLOSE
TO 10KFT THROUGH THE DAY. NIGHTTIME SNOW ACCUMULATIONS WILL MOSTLY
MELT AWAY THROUGH THE DAYTIME.

MONDAY NIGHT...THE TROUGH EXITS EAST AS A RIDGE BUILDS INTO THE
GREAT BASIN. SHOWERS WILL END QUICKLY WEST TO EAST THROUGH THE
EVENING.

RIDGING BUILDS IN TUESDAY AND WEDNESDAY WITH ONLY A FEW HIGH
MOUNTAIN SHOWERS EXPECTED DURING THE AFTERNOON AND EVENING HOURS
AS WE WORK OUT ANY LINGERING MOISTURE. DRY SOUTHWEST FLOW THEN
SETS IN THURSDAY AND WILL CONTINUE INTO THE WEEKEND WITH
TEMPERATURES RETURNING TO ABOVE SEASONAL NORMS AS WE CLOSE OUT
THE WEEK.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 314 AM MDT SAT MAY 18 2013

MID LEVEL CLOUDS AND A FEW LIGHT SHOWERS WILL MOVE ACROSS EASTERN
UTAH AND WESTERN COLORADO THIS MORNING AHEAD OF A COLD FRONT
ADVANCING ACROSS THE GREAT BASIN. THIS FRONT WILL PUSH THROUGH
WESTERN COLORADO THIS AFTERNOON AND EVENING WITH SHOWERS AND
THUNDERSTORMS BECOMING WIDESPREAD AFTER 18Z. EXPECT MOUNTAIN
OBSCURATIONS AS CIGS LOWER IN THE VICINITY OF SHOWERS WITH AREAS
OF MVFR AND EVEN IFR CONDS EXPECTED. SHOWERS ACTIVITY WILL BECOME
MORE FOCUSED ON THE NORTHERN AND CENTRAL MOUNTAINS IN WESTERN
COLORADO AFTER 03Z.

&&

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

$$

SHORT TERM...JDC/JOE
LONG TERM...JOE/JDC
AVIATION...JDC