000
FXUS65 KGJT 131000
AFDGJT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND JUNCTION CO
400 AM MDT MON MAY 13 2013

.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 400 AM MDT MON MAY 13 2013

THE HIGH PRESSURE RIDGE OVER THE WEST WILL FLATTEN IN RESPONSE TO
A TRANSIENT SHORT WAVE TROUGH MOVING ACROSS THE PACIFIC NORTHWEST
TODAY. IN RESPONSE...FLOW WILL SHIFT FROM NORTHWEST TO WEST WHICH
WILL IN TURN ADVECT WARMER AIR BELOW THE 5H LEVEL. THIS WARMING
WILL EFFECTIVELY WIPE OUT THE MID-LEVEL CAP WHICH INHIBITED MOIST
CONVECTION YESTERDAY. CONSEQUENTLY...EXPECT WARMER DAYTIME HIGHS
AND REMOVAL OF CONVECTIVE INHIBITION WILL BRING ABOUT SCATTERED
AFTERNOON SHOWERS AND THUNDERSTORMS OVER THE MOUNTAINS...FAVORING
THOSE RANGES ALONG THE CONTINENTAL DIVIDE AND AND EASTERN UINTA
MOUNTAINS OF NORTHEAST UTAH. FORECAST AND GUIDANCE TEMPERATURES
IN GOOD AGREEMENT...BOTH INDICATED ABOUT 5 DEGREES OF WARMING...
SO MADE ONLY MINOR CHANGES TO FORECAST HIGHS.

SHOWER ACTIVITY WILL DIMINISH AFTER SUNSET ACROSS THE FORECAST
AREA.  RIDGE WILL FLATTEN SLIGHTLY ON TUESDAY AS A TROUGH OF LOW
PRESSURE IMPACTS THE PACIFIC NORTHWEST. CONVECTION WILL FIRE AGAIN
WITH AFTERNOON HEATING WITH SLIGHT CHANCE/CHANCE SHOWERS AND
THUNDERSTORMS EXPECTED WITH SEASONABLY WARM AFTERNOON HIGHS.

.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 400 AM MDT MON MAY 13 2013

GRADIENT TIGHTENS SLIGHTLY TUESDAY NIGHT THROUGH WEDNESDAY NIGHT
WITH SOUTHWEST FLOW OVER THE FORECAST AREA. EXPECT ANOTHER ROUND
OF SLIGHT CHANCE/CHANCE LATE DAY SHOWERS AND THUNDERSTORMS
WEDNESDAY WITH ACTIVITY DIMINISHING WEDNESDAY EVENING. WARM
TEMPERATURES WILL CONTINUE THROUGH THURSDAY.

BREEZY AND WARM CONDITIONS CONTINUE INTO FRIDAY AS A COLD FRONT
ASSOCIATED WITH AN APPROACHING PACIFIC TROUGH CLOSES ON THE AREA.
A FEW AFTERNOON/EVENING SHOWERS AND THUNDERSTORMS ARE POSSIBLE
OVER THE EASTERN UINTA MOUNTAINS. EXPECT SHOWERS AND
THUNDERSTORMS TO INCREASE FRIDAY NIGHT INTO SATURDAYAS THE TROUGH
MOVES ACROSS THE AREA...EXCEPT ACROSS THE SOUTH. ECMWF DEPICTED A
SOMEWHAT SHARPER TROUGH SO ONSET OF SHOWERS DELAYED COMPARED TO
THE GFS FRIDAY NIGHT. TEMPERATURES COOL TO NEAR NORMAL THIS
WEEKEND WITH THE PASSAGE OF THE COLD FRONT ASSOCIATED WITH THIS
SYSTEM. SHOWERS MAY LINGER ACROSS THE NORTHERN MOUNTAINS SUNDAY
ACCORDING TO THE ECMWF IN CONTRAST TO THE DRY GFS.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 400 AM MDT MON MAY 13 2013

VFR CONDITIONS CONTINUE REGION-WIDE THROUGH 18Z TODAY. AFTER THIS
TIME...RISING TEMPERATURES WILL RESULT IN SCATTERED SHOWERS AND
THUNDERSTORMS OVER THE COLORADO DIVIDE MOUNTAINS AND THE EASTERN
UINTAS OF NORTHEAST UTAH. THIS ACTIVITY WILL RESULT IN AREAS OF
MOUNTAIN OBSCURATION AND GUSTY OUTFLOW WINDS UP TO 35 TO 40 KTS.
THE CHANCE OF STORMS PASSING OVER ANY OF THE TAF SITES IS TOO LOW
TO WARRANT MENTION IN THE 12Z TAF ISSUANCE...BUT WILL INCLUDE CB
FOR KASE AND KEGE. COOLING TEMPERATURES WILL BRING AN END TO
THUNDERSTORMS AROUND 03Z TUESDAY AND VFR CONDITIONS WILL RETURN
OVER THE ENTIRE REGION. FOR THE SAKE OF CLARITY...AREAS OUTSIDE
OF THOSE DESCRIBED PREVIOUSLY WILL HAVE VFR CONDITIONS THROUGHOUT
THE NEXT 24 HOURS...BUT MAY EXPERIENCE GUSTY AND ERRATIC OUTFLOW
WINDS FROM SHOWERS AND THUNDERSTORMS.


&&

.FIRE WEATHER...(TONIGHT THROUGH SUNDAY)
ISSUED AT 400 AM MDT MON MAY 13 2013

ABOVE NORMAL WARMTH AND MOSTLY DRY CONDITIONS ARE EXPECTED DURING
THE UPCOMING WEEK WHICH COULD QUICKLY RAISE FIRE WEATHER CONCERNS.
MUCH WILL BE DEPENDENT ON FUEL CONDITIONS...AND LAND AGENCIES ARE
ENCOURAGED TO KEEP THEIR FUELS STATUS UPDATED.

GUSTY SOUTHWEST WINDS SHOULD DEVELOP ON TUESDAY IN ADVANCE OF A DRY
BUT WEAK COLD FRONT. LOCALIZED CRITICAL WIND/LOW HUMIDITY CRITERIA
ARE POSSIBLE TUESDAY AFTERNOON MAINLY NORTH OF I-70 WHERE THE
STRONGER GUSTS ARE EXPECTED. CURRENT FUEL STATUS PRECLUDES ANY FIRE
WEATHER HIGHLIGHT AT THE MOMENT. STRONGER AND MORE WIDESPREAD WIND
WITH LOW HUMIDITY IS ANTICIPATED THURSDAY AND FRIDAY AHEAD OF
ANOTHER PACIFIC SYSTEM MOVING INLAND.

ISOLATED TO SCATTERED DIURNAL SHOWERS AND THUNDERSTORMS ARE EXPECTED
MAINLY OVER THE MTNS ON MOST DAYS THIS WEEK. STORMS WILL BE MAINLY
HIGH-BASED AND LIKELY TO PRODUCE MORE WIND THAN RAIN.

&&

.GJT WATCHES/WARNINGS/ADVISORIES...

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

&&

$$

SHORT TERM...NL/MPM
LONG TERM...NL/MPM
AVIATION...NL
FIRE WEATHER...JAD/NL