Area Forecast Discussion
Issued by NWS Grand Junction, CO

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FXUS65 KGJT 051030
AFDGJT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND JUNCTION CO
430 AM MDT WED AUG 5 2015

.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 430 AM MDT WED AUG 5 2015

THE HIGH PRESSURE IN PLACE OVER THE LAST 24 HOURS WILL FLATTEN TODAY
AS AN UPPER LEVEL TROUGH SWEEPS BY NORTHERN UTAH AND COLORADO THIS
EVENING. THE PRESSURE GRADIENT WILL TIGHTEN TODAY RESULTING IN A
WINDIER DAY ACROSS MUCH OF THE REGION...ESPECIALLY ACROSS THE
NORTH. GUSTS TO 30 MPH OR MORE WILL NOT BE UNCOMMON THIS AFTERNOON
AS WINDS MIX TO THE SURFACE. THOUGH A FEW SHOWERS ARE POSSIBLE
ACROSS NE UTAH AND NW COLORADO TODAY...THE REMAINDER OF THE REGION
WILL SEE JUST A FEW PASSING CLOUDS. THE WINDY CONDITIONS WILL DIE
DOWN AROUND SUNSET IN THE VALLEYS BUT WILL CONTINUE ON AT HIGHER
ELEVATIONS THROUGH THURSDAY MORNING.

THE PRESSURE GRADIENT SLACKENS ON THURSDAY AS HIGH PRESSURE
AMPLIFIES BACK OVER THE REGION. AN ISOLATED SHOWER OR TWO IS
POSSIBLE THURSDAY AFTERNOON OVER THE MOUNTAINS BUT LITTLE ELSE TO
TALK ABOUT. TEMPERATURES WILL REMAIN SLIGHTLY ABOVE NORMAL OVER
THE NEXT COUPLE OF DAYS.

.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 430 AM MDT WED AUG 5 2015

MONSOONAL MOISTURE BEGINS TO SURGE NORTHWARD ACROSS NORTHWEST
ARIZONA AND INTO SOUTHWEST UTAH THURSDAY NIGHT ARRIVING OVER
SOUTHEAST UTAH AND WESTERN COLORADO FRIDAY AFTERNOON. THE MOISTURE
ARRIVES AHEAD OF A PACIFIC LOW PRESSURE SYSTEM WHICH SHIFTS TO
THE WESTERN GREAT BASIN LATE IN THE DAY. AHEAD OF THIS SYSTEM...
PRECIPITABLE WATER VALUES WILL JUMP TO BETWEEN 1.0 AND 1.1 INCHES
OVER SOUTHEAST UTAH WHICH IS AROUND 0.50 OF INCH HIGHER THAN THOSE
EXPECTED THURSDAY AFTERNOON. THE MOISTURE RISE WILL BE LESS
PRONOUNCED OVER WESTERN COLORADO WHERE THE MONSOONAL SURGE WILL
JUST BE BEGINNING. THE INFLUX OF MOISTURE COMBINED WITH DAYTIME
HEATING WILL BRING INCREASED SHOWER AND THUNDERSTORM ACTIVITY.
ADDITIONAL LIFT PROVIDED BY A COOL FRONT MOVING EASTWARD THROUGH
THE AREA COMBINED WITH DIVERGENCE ALOFT ASSOCIATED WITH A 75 KT
JET ON THE LEADING EDGE OF THE PACIFIC TROUGH. THIS WILL LIKELY
YIELD STRONGER STORMS CAPABLE OF PRODUCING HEAVY RAIN...
ESPECIALLY OVER SOUTHEAST UTAH WHERE MOISTURE WILL BE DEEPEST.
DYNAMIC FORCING WILL KEEP SHOWERS AND THUNDERSTORMS GOING WELL
INTO FRIDAY NIGHT AS THE MONSOONAL SURGE PEAKS OVER THE AREA.

SATURDAY NOT LOOKING AS ACTIVE AS DRYER AIR ARRIVES ON THE
BACKSIDE OF THE RAPIDLY WEAKENING PACIFIC TROUGH WHICH MOVES
ACROSS NORTHERN WYOMING LATE IN THE DAY. HOWEVER...ENOUGH MOISTURE
WILL REMAIN TO FUEL AFTERNOON SHOWERS AND THUNDERSTORMS...
ESPECIALLY OVER THE SOUTH WHERE DRYING LESS PREVALENT.

DRIER CONDITIONS WILL PERSIST SUNDAY INTO MONDAY BEFORE THE NEXT
...WEAKER INFLUX OF MONSOON MOISTURE ARRIVES TUESDAY.

TEMPERATURES WILL BE COOLER FRIDAY IN RESPONSE TO THE PASSAGE OF
THE COOL FRONT IN CONCERT WITH INCREASED CLOUDS AND SHOWERS.
CONTINUED CAA FRIDAY NIGHT IS EXPECTED TO BRING EVEN COOLER
TEMPERATURES SATURDAY. DRYING WILL ALLOW TEMPERATURES TO RECOVER
SOMEWHAT ON SUNDAY...STAYING NEARLY STEADY INTO EARLY NEXT WEEK.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 430 AM MDT WED AUG 5 2015

EXPECT VFR CONDITIONS TO PREVAIL AT AIRPORTS ACROSS THE REGION
THROUGH THE NEXT 24 HOURS. ISOLATED MOUNTAIN THUNDERSTORMS ARE
EXPECTED BETWEEN 18Z AND 02Z...MAINLY OVER THE EASTERN UINTA AND
SAN JUAN MOUNTAINS. BREEZY SOUTHWEST WINDS WILL IMPACT AREAS ALONG
AND NORTH OF THE I-70 CORRIDOR DURING THE AFTERNOON WITH WIND
GUSTS OF 30 TO 35 MPH ACROSS THE NORTHERN BORDER REGION THROUGH
EARLY EVENING.

&&

.FIRE WEATHER...
ISSUED AT 430 AM MDT WED AUG 5 2015

AFTER ANALYZING TUESDAY/S WEATHER DATA ACROSS FIRE WEATHER ZONES
200...202 AND 203...DECIDED THE LIKELIHOOD OF RELATIVE HUMIDITIES
FALLING BELOW 15 PERCENT IS LIKELY THIS AFTERNOON AND EARLY THIS
EVENING. A DISTURBANCE MOVING ACROSS NORTHERN UTAH INTO SOUTHWEST
WYOMING WILL TIGHTEN THE PRESSURE GRADIENT RESULTING IN BREEZY
SOUTHWEST FLOW. FREQUENT WIND GUSTS TO 25 MPH OR GREATER ARE
EXPECTED...ESPECIALLY ACROSS AREAS IN NORTHEAST UTAH AND NORTHWEST
COLORADO ALONG AND NORTH OF INTERSTATE 70.

&&

.GJT WATCHES/WARNINGS/ADVISORIES...

CO...RED FLAG WARNING FROM NOON TODAY TO 8 PM MDT THIS EVENING FOR
     COZ200-202-203.

UT...NONE.

&&

$$

SHORT TERM...JAM
LONG TERM...NL
AVIATION...NL
FIRE WEATHER...JAM



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