Area Forecast Discussion
Issued by NWS Grand Junction, CO

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000
FXUS65 KGJT 222136
AFDGJT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND JUNCTION CO
336 PM MDT TUE JUL 22 2014

.SHORT TERM...(TONIGHT THROUGH WEDNESDAY NIGHT)
ISSUED AT 330 PM MDT TUE JUL 22 2014

LARGE UPPER LEVEL HIGH PRESSURE CENTERED OVER NEW MEXICO WILL
REMAIN ESSENTIALLY IN PLACE THROUGH WEDNESDAY. RELATIVELY HIGHER
MOISTURE CONTENT ACROSS FAR SOUTH AND TOWARD THE ELKS AND SAWATCH
RANGE WILL RESULT IN ISOLATED STORMS LATE TODAY. ANY CONVECTION
WILL DISSIPATE QUICKLY THIS EVENING. ANTICYLONIC FLOW AROUND THE
HIGH WILL BRING 0.75 TO 1.00 INCH PRECIPITABLE WATER AIR MASS
LURKING TO OUR SOUTH OVER OUR REGION ON WEDNESDAY. ALONG WITH A
CLUSTER OF WEAK SHORTWAVES APPROACHING AND ANOTHER DAY OF STRONG
HEATING /INSTABILITY/...SHOULD SEE EARLIER CLOUD DEVELOPMENT AND
GREATER COVERAGE OF THUNDERSTORMS BY WEDNESDAY AFTN. STORMS UNDER
THE CENTER OF THE HIGH IN THE VICINITY OF SAN JUANS AND WILL HAVE
TO BE WATCHED FOR A FLASH FLOOD THREAT. ELSEWHERE THERE WILL BE SOME
STEERING FLOW TO MOVE STORMS ALONG AND HOPEFULLY DECREASE THREAT
OF FLASH FLOODING. CONFIDENCE AND MARGINAL EXPECTED PRECIP WATER
NOT HIGH ENOUGH TO SUPPORT A FLASH FLOOD WATCH AT THIS TIME. MAX
TEMPS WED SHOULD BE A FEW DEGREES COOLER THAN TODAY WITH GREATER
CLOUD COVER EXPECTED.

.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 330 PM MDT TUE JUL 22 2014

THE MOISTURE PLUME WILL BE FORCED SOUTHWARD ON THURSDAY AS A
RATHER ROBUST SYSTEM BREAKS FROM THE NORTHWEST SEABOARD AND INTO
THE NORTHERN ROCKIES. THERE WILL BE ISOLATED STORMS POSSIBLE NORTH
OF HIGHWAY 40...BUT THE BEST COVERAGE WILL BE SHIFTING SOUTH OF
THE HIGH PLATEAUS...CENTERED ON THE CENTRAL AND SOUTHERN
MOUNTAINS. SHEAR WILL BE STRONGER ON THURSDAY AND SHOULD LEAD TO
BETTER STORM ORGANIZATION AND LIFESPAN. THIS WILL BRING A THREAT
OF HEAVIER RAIN OVER THE SOUTHERN CWA AND MAYBE SOME STRONGER
WINDS IN THE DRIER AIR TO THE NORTH. TEMPERATURES WILL BE
CLOSER...BUT SHOULD EXCEED ...NORMAL RANGES AGAIN ON THURSDAY
THOUGH THICKER CLOUD COVER IN THE SOUTH MAY TEST THIS THEORY. THE
UPPER LEVEL HIGH PRESSURE CIRCULATION WILL BE NUDGED SOUTHWARD BY
THE WAVE MOVING ACROSS THE US/CANADA BORDER. THIS WILL DISRUPT ANY
DIRECT FEED OF MONSOONAL MOISTURE BUT MOISTURE TRAPPED UNDER THE
RIDGE WILL BE SUFFICIENT ENOUGH TO SPARK ANOTHER ROUND OF
AFTERNOON CONVECTION ON FRIDAY. AGAIN THE CENTRAL AND SOUTHERN
COLORADO MOUNTAINS WILL BE FAVORED FOR THE MOST COVERAGE OF
THUNDERSTORM ACTIVITY...WITH NORTHEAST UTAH REMAINING DRY. THE
ENERGY TO OUR NORTH WILL BE COMBINING A LARGER LOW PRESSURE SYSTEM
OVER THE GREAT LAKES AND WILL BE FORMING A DEEPER EASTERN CONUS
TROUGH LATE THIS WEEKEND INTO EARLY NEXT WEEK...A COMMON THEME
THIS SUMMER. AS A RESULT THE WESTERN RIDGE WILL BECOME NEGATIVELY
TILTED FROM THE SOUTHERN HIGH PLAINS TO THE NORTHERN ROCKIES AND
LEAVE THE BEST MOISTURE TO OUR WEST. A DOWNTURN IN CONVECTION IS
EXPECTED BUT A FRONT LAYING UP AGAIN THE DIVIDE WILL KEEP STORMS
FOCUSED THERE GOING INTO MONDAY. THROUGH EARLY NEXT WEEK THE RIDGE
AXIS WILL BE TILTED EASTWARD BY THE NEXT SYSTEM ARRIVING TO THE
PACNW...AND THE MOISTURE OUT WEST WILL TOPPLE INTO THE EASTERN
GREAT BASIN AND COLORADO ROCKIES. HIGHS WILL REMAIN AT OR ABOVE
NORMAL THROUGH THE FORECAST.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 330 PM MDT TUE JUL 22 2014

VFR CONDITIONS WILL DOMINATE THROUGH NOON WEDNESDAY. ISOLATED
CIRCUMNAVIGABLE CONVECTIVE TSRA/SHRA WILL CONTINUE UNTIL 03Z THIS
EVENING ALONG THE SOUTHERN CONTINENTAL DIVIDE. WINDS WILL SWITCH
FROM UPVALLEY TO DOWNVALLEY BETWEEN 02Z-04Z THIS EVENING.
WEDNESDAY AFTERNOON...A MORE SIGNIFICANT INCREASE IN MOISTURE AND
INSTABILITY IS EXPECTED WITH SCATTERED COVERAGE OF SHRA/TSRA. FOR
NOW WILL CARRY VICINITY SHOWERS IN TAFS AFTER 18Z.


&&

.FIRE WEATHER...
ISSUED AT 330 PM MDT TUE JUL 22 2014

MOISTURE WILL BE ARRIVING FROM THE SOUTH TO BRING AN UPTICK TO
SHOWER AND THUNDERSTORM ACTIVITY ON WEDNESDAY. THE LOWER LAYERS
OF THE ATMOSPHERE WILL REMAIN DRY ACROSS NORTHWEST COLORADO
BEFORE THE BEST MOISTURE ARRIVES AND SETS THE STAGE FOR VIRGA AND
GUSTY OUTFLOW WINDS. WIDESPREAD CRITICAL FIRE WEATHER CONDITIONS
ARE NOT ANTICIPATED AT THIS TIME...BUT THE COMBINATION OF HUMIDITY
BELOW 15 PERCENT AND THE ABOVE MENTIONED WIND MAY LEAD TO
LOCALIZED AREAS OF CONCERN IN THE LOWER WESTERN CWA VALLEYS
TOMORROW AFTERNOON AND EARLY EVENING.

&&

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

$$

SHORT TERM...BEN
LONG TERM...15
AVIATION...JOE
FIRE WEATHER...15


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