Area Forecast Discussion
Issued by NWS Grand Junction, CO

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FXUS65 KGJT 180923
AFDGJT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND JUNCTION CO
323 AM MDT FRI APR 18 2014

.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 323 AM MDT FRI APR 18 2014

MOSTLY DRY...MILD BUT BREEZY WEATHER TODAY WILL GIVE WAY TO SOME
SHOWERS AND ISOLATED THUNDERSTORMS TONIGHT AND SATURDAY.

HIGH CLOUDS WILL INCREASE FROM THE WEST THIS MORNING AS THE UPPER
RIDGE SLIDES TO OUR EAST AND TWO PACIFIC SYSTEMS MOVE INLAND. THE
NORTHERN STREAM DISTURBANCE WILL CRUISE ACROSS THE NORTHERN ROCKIES
TODAY PUSHING A MOSTLY DRY COLD FRONT INTO THE NORTH THIS
EVENING...WHERE IT WILL STALL AND DISSIPATE AS THE UPPER TROUGH
CONTINUES INTO THE NORTHERN PLAINS. A SOUTHERN STREAM UPPER LOW WILL
LIFT ACROSS SRN CA TODAY TO THE 4 CORNERS BY LATE SATURDAY. THIS SRN
STREAM LOW WILL BECOME THE MAIN PLAYER IN OUR WEATHER TONIGHT AND
SATURDAY.

A TIGHTENING GRADIENT AS THE NORTHERN STREAM TROUGH MOVES BY WILL
CREATE GUSTY WINDS THIS AFTERNOON ESPECIALLY NEAR THE WY BORDER.
DAYTIME INSTABILITY SHOULD LEAD TO ISOLATED TO PERHAPS SCATTERED
SHOWERS THIS AFTERNOON MAINLY OVER THE CENTRAL AND SOUTHERN MTNS
LATE THIS AFTERNOON AS THE VEIL OF HIGH CLOUDS INHIBIT CONVECTION.
MAY SEE A FEW ISOLATED THUNDERSTORMS...WHICH WOULD BE DRY WITH THE
POTENTIAL FOR STRONG GUSTY OUTFLOW WINDS.

MOISTURE DEEPENS AND LOWERS TONIGHT TONIGHT AS SRN CA LOW MOVES INTO
AZ. SHOULD SEE AN INCREASE IN SHOWERS ACROSS THE SOUTH THIS EVENING
SPREADING NORTH TO THE BOOKCLIFFS AND FLATTOPS BY MORNING AS THE
MOISTURE FRONT PUSHES NORTH AND VORTICITY LOBE ROTATES UP INTO SE
UT/SW CO AHEAD OF THE MAIN LOW. ISOLATED THUNDERSTORMS REMAIN
POSSIBLE TONIGHT SOUTH OF I-70 TONIGHT WITH THE THREAT OF GUSTY
OUTFLOW WINDS. 700 MB TEMPS DROP TO AROUND ZERO CELSIUS SOME SNOW
OVER THE CENTRAL AND SOUTHERN MOUNTAINS AND POSSIBLY HIGH VALLEYS
AFTER MIDNIGHT AND INTO SATURDAY MORNING.

AFTER A BIT OF DOWNTURN SATURDAY MORNING...INSTABILITY DUE TO COOLER
AIR ALOFT COMBINED WITH LARGER-SCALE LIFT AS THE UPPER LOW
APPROACHES SHOULD GIVE SHOWER ACTIVITY A BOOST SATURDAY AFTERNOON.
WILL KEEP THUNDERSTORMS TO ISOLATED COVERAGE...HOWEVER...DUE TO
MOSTLY CLOUDY SKIES INHIBITING GOOD SURFACE HEATING.

.LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY)
ISSUED AT 323 AM MDT FRI APR 18 2014

CONVECTIVE SHOWERS WILL SLOWLY COME TO AN END SATURDAY NIGHT INTO
SUNDAY MORNING AS THE TROUGH RESPONSIBLE SHIFTS TO THE FRONT
RANGE. NAM12 CONTINUES TO PAINT RATHER MEAGER PRECIP AMTS THROUGH
THE PERIOD WHILE GFS/EC MORE BULLISH. THIS IS THE WAY IT GOES WITH
CONVECTIVE TYPE ACTIVITY FOR MODELS SO SCHC TO CHC FOR VALLEYS AND
CHC TO LIKELY LOOKS GOOD FOR MTNS.

WEAK RIDGING BUILDS IN SUNDAY AS SMALL PIECES OF ENERGY MANAGE TO
FIRE OFF SOME CONVECTION BOTH SUNDAY AND MONDAY EVENING FAVORING
HIGHER TERRAIN WHERE LAPSE RATES AND INSTABILITY LOOKS TO BE
HIGHEST. BY TUESDAY...THE RIDGE BREAKS DOWN AS A STRONG COLD FRONT
APPROACHES FROM THE PAC NW. AS EARLY AS TUE AFTN WE SHOULD FEEL
THE EFFECTS AS THE GRADIENT TIGHTENS AND SOME GUSTY WINDS ARE
FELT ACROSS THE CWA. THESE WINDS WILL CONTINUE TO STRENGTHEN AS
THE FRONT AND UPPER LEVEL SUPPORT CONTINUE TO APPROACH THE AREA.
LATEST GUIDANCE HAS GFS COMING AROUND TO EC THINKING OF KEEPING
THE HEAVIEST PRECIP WELL TO OUR N WHILE SPOTTY PRECIP WILL BE
POSSIBLE TUE AFTN THRU WED AFTN. H7 WINDS STILL SHOW 55 TO 60KTS
WHICH WILL LIKELY MIX TO THE SURFACE SO DO ANTICIPATE PLENTY OF
WIND ADVISORIES...IF NOT HIGH WIND WARNINGS FOR SOME SPOTS...ALONG
WITH BLOWING DUST ADVISORIES FOR SOME AREAS AS WELL. WITH THIS
MUCH WIND...WE CAN ALSO EXPECT PLENTY OF DUST ON SNOW WHICH WILL
INCREASE SNOWMELT FOR MOUNTAIN LOCALES...THINKING SAN JUANS ATTM.
THIS IS NOT ETCHED IN STONE HOWEVER AS WE REMAIN 5 DAYS OUT SO
PLENTY OF TIME FOR SOME MODEST TO MAJOR CHANGES IN THE FORECAST.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 323 AM MDT FRI APR 18 2014

CONDITIONS WILL DETERIORATE AS THE DAY PROGESSES WITH RAIN SHOWERS
EXPECTED ACROSS THE AREA WITH SNOW SHOWERS AT THE HIGHEST
ELEVATIONS WITH SOME THUNDERSTORMS THROWN IN FOR GOOD MEASURE
AFTER 21Z. GUSTY WINDS ARE ALSO POSSIBLE UNDER AND NEAR THE
STRONGER CELLS ALONG WITH SOME TURBULENCE. AERODROMES SOUTH OF
I-70 WILL SEE THE WORST WEATHER FIRST BEFORE SHIFTING NORTHWARD
THIS AFTERNOON AND EVENING. A SMALL LULL IS POSSIBLE BETWEEN 00Z
TO 06Z BEFORE ANOTHER ROUND OF PRECIP MOVES IN...AGAIN FAVORING
AREAS SOUTH 12Z ONWARDS TOMORROW.

&&

.GJT WATCHES/WARNINGS/ADVISORIES...

CO...NONE.
UT...NONE.

&&

$$

SHORT TERM...JAD
LONG TERM...TGR
AVIATION...TGR



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