Area Forecast Discussion
Issued by NWS Grand Junction, CO

Home | Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary Off
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 131658
AFDGJT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND JUNCTION CO
1058 AM MDT SUN JUL 13 2014

.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 431 AM MDT SUN JUL 13 2014

TODAY...HIGH PRESSURE WILL REMAIN CENTERED OVER THE GREAT BASIN
WITH DRIER NW FLOW OVER THE AREA. OVER EASTERN UT...NW AND MOST OF
CENTRAL CO...AFTERNOON CONVECTION WILL CONTINUE TO BE SUPPRESSED
BY SUBSIDENCE WITH LESS MOISTURE AVAILABLE AS WELL. LOW LEVEL
MOISTURE OVER THE SAN JUAN MOUNTAINS AND THE CONTINENTAL DIVIDE AS
FAR NORTH AS THE PRESIDENTIAL RANGE...AS WELL AS THE LOWER
ELEVATIONS OF THE FOUR CORNERS...WILL AGAIN SUPPORT A HIGHER
AREAL COVERAGE OF SHOWERS AND THUNDERSTORMS THIS AFTERNOON. DEW
POINTS AT DURANGO AND CORTEZ WILL BE IN THE MID 50S...WITH DEW PTS
AT ELEVATED SITES LIKE TELLURIDE AND ASPEN IN THE MID 40S. SO
EXPECT THAT SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS WILL
DEVELOP OVER THESE AREAS AGAIN TODAY...BUT BE SHUNTED A BIT
FURTHER EAST COMPARED TO SATURDAY. CENTRAL AND NORTHWEST CO AND NE
UT WILL BE ON THE HOT SIDE AGAIN UNDER SUNNY TO PARTLY CLOUDY
SKIES.

TONIGHT AND MONDAY...UPPER LEVEL HIGH PRESSURE WILL REMAIN SUPRESSED
WEST OF THE ROCKIES DURING THIS TIME FRAME AS AN ANOMALOUSLY STRONG
CYCLONE MOVES OVER THE GREAT LAKES/MIDWEST PORTION OF THE CONUS.
WITH THE CENTER OF THIS CIRCULATION BACK OVER THE INTERMOUNTAIN WEST
A DRIER NORTHERLY FLOW REGIME WILL BE IN PLACE AND THIS SHOULD ALLOW
DIURNALLY DRIVEN CONVECTION TO DISOLVE AGAIN AFTER SUNSET TOMORROW.
LOOKING AT GOES DERIVED IMAGERY...REMNANTS OF THIS MOISTURE WILL BE
WRAPPING TO THE SOUTH OF THE ANTICYLONE OVER NEVADA...WHILE THE A
STRONGER PUSH COMING UP THE GULF OF CALIFORNIA WILL BE WRAPPING INTO
THE WESTERN SIDE OF THE HIGH. THETA SURFACES DO NOT SHOW A STRONG
PUSH TOWARD OUR CWA ON MONDAY BUT INSTABILITY AND UPLIFT WILL BE
INCREASING. THE SHOWERS AND THUNDERSTORMS LOOK TO BE MAINLY TERRAIN
BASED BUT THE PACIFIC JET WILL BE DIGGING DOWN THE HIGH PLAINS AND
MAY ADD SOME ASCENT TO OUR NORTHEAST ZONES LATE IN THE DAY. HIGHS
WILL BE RUNNING AOA NORMAL THE NEXT FEW DAYS AS MOISTURE SLACKENS
AND GRIDS ON TRACK.

.LONG TERM...(MONDAY NIGHT THROUGH SATURDAY)
ISSUED AT 401 AM MDT SUN JUL 13 2014

MONDAY NIGHT INTO TUESDAY...MOISTURE AND SYNOPTIC LIFT INCREASE
DURING THIS PERIOD AND IT LOOKS TO BE RATHER ACTIVE. NOCTURNAL
THUNDERSTORMS WILL BE POSSIBLE AS THIS MOISTURE LEAKS UNDER THE
RIDGE. A STRONGER WAVE PASSING TO OUR NORTH DOESN/T APPEAR TO
DIRECTLY AFFECT US...BUT IT WILL TIGHTEN THE THERMAL PATTERN ALOFT
AND DRAG THE DIRECT CIRCULATION OF THE JET OVER OUR NORTHERN CWA
TUESDAY. AGAIN THIS DOES NOT SEEM TO BE A DIRECT HIT OF THE MONSOON
BUT RATHER MOISTURE INFILITRATING THE FLOW. PWATS DO PUSH BACK TO
NEAR OR ABOVE 1 INCH. STORMS WILL BE MOVING FASTER IN THIS REGIME
WHICH MAY LIMIT THE FLASH FLOOD POTENTIAL...BUT INCREASING SHEAR
ALOFT WILL ALLOW THE STORMS TO SURVIVE LONGER AND HAVE THE POTENTIAL
FOR SOME HAIL AND GUSTY OUTFLOW WINDS. MILD OVERNIGHT TEMPERATURES
DUE TO INCREASING MOISTURE WILL ALSO COOL SOME ON TUESDAY AS PLENTY
OF CLOUD COVER SHOULD BE IN PLACE BY EARLY AFTERNOON.

TUESDAY NIGHT THROUGH WED...THE BEST COMBINATION OF DYNAMIC LIFT
AND MOISTURE ASSOCIATED WITH THE SHORTWAVE APPEARS TO BE TIMED
BETWEEN LATE TUESDAY AFTERNOON AND TUESDAY EVENING. BELIEVE
SIGNIFICANT SHOWERS AND THUNDERSTORMS COULD PERSIST UNTIL MIDNIGHT
WITH GRADUALLY DECREASING ACTIVITY OVERNIGHT. THE EC DIFFERS FROM
THE GFS ON THE TUE NIGHT AND WED PROGNOSIS...AS IT SHOWS THE
STRONGEST PORTION OF THE SHORTWAVE TROUGH IMPACTING THE AREA TUE
EVENING THROUGH WED. THE TROUGH IN THE EC IS STRONGER...MOVES MORE
SLOWLY...AND LIKE THE GFS SOLUTION...SHOULD AFFECT EASTERN CO MORE
SIGNIFICANTLY.

WED NIGHT THROUGH SATURDAY...THE GREAT BASIN RIDGE SHOULD
REESTABLISH ITSELF AND BRING DRIER CONDITIONS TO THE AREA THROUGH
THU NIGHT. ON FRIDAY AND SATURDAY...BOTH THE GFS AND EC SHOW THE
NEXT TROUGH AFFECTING THE AREA. THERE IS THE POTENTIAL FOR ANOTHER
SIGNIFICANT UPTURN IN SHOWERS AND THUNDERSTORMS AS THIS TROUGH
MOVES IN FROM THE NORTHWEST. VERTICAL WIND SPEED AND DIRECTIONAL
SHEAR INCREASE...ALONG WITH MOISTURE AND DYNAMIC LIFT FROM THE
PASSING SHORTWAVE.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1057 AM MDT SUN JUL 13 2014

CONVECTION HAS BEGUN TO DEVELOP OVER THE HIGHER TERRAIN LATE THIS
MORNING AND WILL INCREASE THIS AFTERNOON. THE SAN JUAN MOUNTAINS
AND CENTRAL MOUNTAINS ALONG THE CONTINENTAL DIVIDE WILL BE
FAVORED. ACTIVITY WILL SPREAD INTO THE VALLEYS NEAR THESE FAVORED
AREAS LATE THIS AFTERNOON. BRIEF HEAVY RAIN WILL BE POSSIBLE...
HOWEVER STORM MOVEMENT FROM THE NORTH IS EXPECTED TO BE A LITTLE
FASTER THAN THE PREVIOUS FEW DAYS. LOCAL MVRF CONDITIONS WILL BE
POSSIBLE WITH THESE STORMS. BY 03Z...MOST CONVECTION WILL HAVE
DIMINISHED...THOUGH AN ISOLATED SHOWER OR THUNDERSTORM WILL BE
POSSIBLE OVERNIGHT IN THE HIGHER SOUTHERN MOUNTAINS.

&&

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

$$

SHORT TERM...CC/15
LONG TERM...CC/15
AVIATION...EH


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