Area Forecast Discussion
Issued by NWS Grand Junction, CO

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FXUS65 KGJT 212127
AFDGJT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND JUNCTION CO
327 PM MDT TUE APR 21 2015

.SHORT TERM...(TONIGHT THROUGH WEDNESDAY NIGHT)
ISSUED AT 327 PM MDT TUE APR 21 2015

A CLOSED LOW AT H7 OVER SOCAL WILL SPIN SOME ENERGY TOWARD THE 4
CORNERS TONIGHT. ISOLATED SHOWERS AND THUNDERSTORMS OVER THE
MOUNTAINS THIS EVENING WILL TAPER OFF AROUND SUNSET AS DIURNAL
HEATING CEASES...BUT A FEW SHOWERS MAY PERSIST OVER THE HIGHER
TERRAIN OF SOUTHEAST UTAH THROUGH THE NIGHT.

SHORT WAVE ROTATING NORTHWARD AHEAD OF SRN CALIF CLOSED LOW
CIRCULATION GETS STRETCHED. MODELDATA SHOWING SHOWERS WITH
ISOLATED THUNDERSTORMS WILL FORM IN THE AREA OF DIVERGENCE...WITH
THE HIGHEST CHANCE OVER THE SAN JUAN MOUNTAINS. THESE SHOWERS WILL
MOVE NNE AND SPREAD INTO THE NRN HALF AS THE DAY PROGRESSES.
THE MAJORITY OF THE SCATTERED EVENING SHOWERS ARE EXPECTED TO BE
ALONG AND NORTH OF I70 BY EVENING BEFORE DIMINISHING OVERNIGHT.

.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 327 PM MDT TUE APR 21 2015

DRIER AIR IS EXPECTED TO SPREAD ACROSS THE FORECAST AREA ON
THURSDAY...BUT SURFACE HEATING AND CONDITIONAL AFTERNOON INSTABILITY
SHOULD RESULT IN SCATTERED SHOWERS/ISOLATED STORMS. THE SAN
JUAN/ELK MOUNTAINS STAND THE BEST CHANCE OF SHOWERS GIVEN THE
PROXIMITY OF UPPER LEVEL JET AND BETTER GRADIENT FLOW FOR
OROGRAPHIC LIFT. LESS CONVECTIVE ACTIVITY IS EXPECTED WEST OF THE
COLORADO HIGH COUNTRY (WITH THE EXCEPTION OF THE ERN UINTA
MOUNTAINS).

CLOSED LOW EJECTS MAINLY EASTWARD AND BECOMES AN OPEN WAVE IN THE
PROCESS THURSDAY NIGHT AND FRIDAY. WINDS ALOFT VEER AND BECOME
NWLY. ANOTHER ROUND OF DIUNALLY DRIVEN AFTERNOON SHOWERS/ISOLATED
STORMS ARE EXPECTED AGAIN ACROSS THE ENTIRE FORECAST AREA. THIS
SCENARIO REPEATS ITSELF ON SATURDAY AS A TROUGH AXIS CROSSES THE
CENTRAL ROCKIES.

A DRYING TREND BEGINS ON SUNDAY AS RIDGE BUILDS ACROSS THE
INTERIOR WEST...ALTHOUGH THE THREAT OF DIURNAL SHOWERS/STORMS
CONTINUES OVER THE COLORADO HIGH COUNTRY. BY MONDAY AND
TUESDAY...WARMING TREND WITH CLEARER CONDITIONS ARE EXPECTED.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1127 AM MDT TUE APR 21 2015

VFR WILL PREVAIL AT THE TAF SITES FOR THE MAJORITY OF THE NEXT 24
HOURS. ISOLATED POCKETS OF MVFR ARE POSSIBLE OVER THE HIGHER
TERRAIN TODAY BUT THE LIKELIHOOD OF ANY TAF SITE REACHING BELOW
VFR CONDITIONS IS LOW. SHOWERS AND THE OCCASIONAL THUNDERSTORM IN
THE MOUNTAINS MAY CAUSE GUSTY WINDS UP TO 30 MPH...BUT WITHOUT
MUCH MOISTURE ACROSS THE AREA THESE IMPACTS ARE EXPECTED TO BE
RATHER MINIMAL AND ISOLATED. ANY PRECIPITATION WHICH DEVELOPS
WILL BE OVER BY 02Z.


&&

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

$$

SHORT TERM...JAM/PF
LONG TERM...PF
AVIATION...JAM


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