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000
FXUS65 KGJT 151659
AFDGJT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND JUNCTION CO
1059 AM MDT SAT JUN 15 2013

.UPDATE...
ISSUED AT 1058 AM MDT SAT JUN 15 2013

WATER VAPOR AND DERIVED GOES IMAGERY SHOWING MOISTURE WORKING UP
THROUGH THE 4 CORNERS REGION THIS MORNING...WITH FORECAST PWAT
PLOTS SHOWING AN UPWARD TREND CONTINUING THROUGH THE AFTERNOON
PEAKING NEAR HALF OF AN INCH AND DOUBLING THE 12Z KGJT RAOB. THIS
MOISTURE IS MAINLY LIMITED TO THE 600MB OR ABOVE WITH SOME WEB
CAMS IN THE SOUTH SHOWING SOME VIRGA FALLING. WITH LIFT MAINLY
OROGRAPHIC NOT MUCH OF A CHANCE OF SEEING MUCH PCPN REACHING THE
GROUND THE NEXT FEW HOURS. THE MAIN WAVE THAT WILL HELP WITH
LARGE SCALE ASCENT IS MOVING THROUGH SOUTHERN TIP OF NEVADA THIS
AM AND SHOULD BE HERE BY PEAK HEATING TO HELP BRING A BETTER
COVERAGE OF CONVECTION THIS AFTERNOON. HOWEVER LARGE DRY LAYER IN
THE LOWER ATMOSPHERE WILL KEEP A THREAT OF DRY THUNDERSTORMS OVER
THE AREA...WITH LITTLE CHANCE OF WETTING RAINS. WINDS ARE LIGHTER
TOWARD THE TOP OF THE MIXED LAYER TODAY BUT THE VIRGA/LIGHT
SHOWERS SHOULD HELP BRING SOME STRONGER WIND GUSTS DOWN AS WELL.

&&

.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 301 AM MDT SAT JUN 15 2013

MODELS CONTINUE TO HIGHLIGHT STREAM OF MOISTURE MOVING INTO
SOUTHERN AREAS OF UTAH AND COLORADO THIS MORNING AND OVERSPREADING
THE REST OF THE CWA AS THE DAY PROGRESSES. 320K MOISTURE TRANSPORT
VECTORS ALSO CORROBORATE THIS IDEA.  THIS STREAM IS IN RESPONSE TO
HIGH PRESSURE CENTERED OVER THE GULF OF MEXICO ALLOWING SOUTHERLY
FLOW TO ADVECT THIS MOISTURE NORTHWARD. IN FACT...THIS MOISTURE
APPEARS ALMOST MONSOON-LIKE BUT WELL TO EARLY FOR THAT TO BE THE
CASE. ALONG WITH THE MOISTURE...A WEAK UPPER LEVEL JET WILL SET UP
OVER UT/CO ALLOWING SOME CONVECTIVE DEVELOPMENT THIS AFTERNOON.
FORECAST SKEW-T/S CONTINUE TO SHOW INVERTED V PROFILES INDICATING
DRY THUNDERSTORMS WITH ERRATIC AND GUSTY OUTFLOW WINDS BEING THE
MAIN CONCERN. WITH THIS IN MIND...EXPANDED THE RED FLAG WARNING TO
THE GRAND VALLEY AND ALL AREAS SOUTH FOR DRY LIGHTNING AND
CRITICAL FUELS. NUMEROUS FIRE STARTS HAVE BEEN REPORTED BECAUSE OF
THE STORMS ON THURSDAY AND EXPECT STORM COVERAGE TO BE A BIT
GREATER TODAY...THUS THE POSSIBILITY OF MORE FIRE STARTS.

SHOWERS AND THUNDERSTORMS WILL COLLAPSE QUICKLY THIS EVENING AS
DAYTIME HEATING CEASES. WINDS WILL FOLLOW THIS TREND AS WELL.

A SHORT-WAVE RIDGE AXIS WILL SET UP OVER THE ROCKIES BUT EVEN SO
SOME VERY ISOLATED SHOWERS AND STORMS WILL BE POSSIBLE ALONG THE
DIVIDE.  WINDS WILL CONTINUE TO BECOME LIGHT AS THE GRADIENT
LOOSENS THROUGH EARLY NEXT WEEK.

.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 301 AM MDT SAT JUN 15 2013

RIDGE VERY GRADUALLY SHIFTS EASTWARD OVER THE CENTRAL PLAINS THROUGH
EARLY NEXT WEEK. SOME RESIDUAL MOISTURE REMAINS BOTH SUNDAY AND
MONDAY...SUNDAY FAVORING THE CENTRAL MOUNTAINS AND SAN JUANS. WITH
PRECIPITABLE WATER FAIRLY LOW...MANY STORMS MAY BE DRY...ESPECIALLY
THOSE AT LOWER ELEVATIONS.

THE REMAINDER OF THE LONG-TERM PERIOD REMAINS WARM AND DRY AS A
DEEP AREA OF LOW PRESSURE MOVES ALONG THE US/CANADIAN BORDER. AS
IT DOES SO...WINDS WILL INCREASE FOR MUCH OF THE INTERMOUNTAIN
WEST ESPECIALLY WEDNESDAY AND THURSDAY INCREASING FIRE WEATHER
CONCERNS. TEMPERATURES WILL CONTINUE TO RUN ABOUT 5 DEGREES ABOVE NORMAL.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1058 AM MDT SAT JUN 15 2013

MOISTURE CONTINUES TO WORK NORTHWARD MAINLY IN THE FORM OF MID
LEVEL CLOUDINESS AND SOME VIRGA ACROSS SOUTHWEST COLORADO THIS
MORNING. CONVECTION...WITH THE THREAT OF GUSTY AND ERRATIC WINDS
GUSTS...SHOULD EXPAND IN COVERAGE THROUGH THE AFTERNOON WITH
HEATING AN UPSTREAM WAVE HELPING WITH SPREAD THUNDERSTORMS OVER
THE CENTRAL AND SOUTHERN HIGH TERRAIN. THE FAR EASTERN FORECAST
TERMINALS...KASE AND KEGE MAY SEE SOME VCTS BUT CONFIDENCE STILL
QUITE LOW ATTM. THE MAIN THREAT TO AVIATION THIS AFTERNOON AND
EARLY EVENING WILL BE LOCALLY GUSTY WINDS NEAR ANY VIRGA OR
SHOWERS ASSOCIATED WITH THE STRONGER STORMS. VFR IS EXPECTED TO
PREVAIL BUT UNPREDICTABLE WIND GUSTS MAY LOWER VISIBILITY DUE TO
BLOWING DUST.

&&

.FIRE WEATHER...
ISSUED AT 301 AM MDT SAT JUN 15 2013

ON SATURDAY...MOISTURE INCREASES INTO THE FOUR CORNERS. THIS WILL
ALLOW THUNDERSTORMS TO DEVELOP IN THE SOUTHERN AREAS OF THE
FORECAST AREA EARLY THIS AFTERNOON BEFORE SPREADING NORTHWARD TO
THE GRAND VALLEY BY MID-AFTERNOON.   SOME STORMS WILL PRODUCE
WETTING RAINS BUT THERE IS GOOD POTENTIAL FOR DRY LIGHTNING ALONG
WITH GUSTY OUTFLOW WINDS.

A RED FLAG WARNING REMAINS IN EFFECT FOR ZONE 207 AND HAS ALSO
BEEN EXPANDED TO INCLUDE ZONES 203, 290, 291, 292, AND 293 THROUGH
SATURDAY EVENING FOR DRY LIGHTNING.

SUNDAY AND MONDAY...LATE DAY STORMS WILL BE MORE ISOLATED IN
COVERAGE MAINLY OVER THE MOUNTAINS. EXPECT A DRYING TREND BEGINNING
MONDAY NIGHT AS TROUGH OF LOW PRESSURE SHIFTS FROM THE EASTERN PACIFIC
INTO THE GREAT BASIN. DAYTIME TEMPERATURES REMAIN ABOVE NORMAL WITH
LOW HUMIDITY.

TUESDAY...GRADIENT BEGINS TO TIGHTEN AGAIN AS LOW PRESSURE MOVES
INTO PAC NW. WILL BE KEEPING AN EYE ON THESE CONDITIONS FOR CONCERNS
NEXT WEEK.

&&

.GJT WATCHES/WARNINGS/ADVISORIES...
CO...RED FLAG WARNING UNTIL 8 PM MDT THIS EVENING FOR COZ203-207-
     290>293.

UT...NONE.
&&

$$

UPDATE...15
SHORT TERM...TGR/JAM
LONG TERM...TGR/JAM
AVIATION...15
FIRE WEATHER...TGR/JAM