Area Forecast Discussion
Issued by NWS Grand Junction, CO

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FXUS65 KGJT 061705
AFDGJT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND JUNCTION CO
1105 AM MDT MON JUL 6 2015

.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 337 AM MDT MON JUL 6 2015

AFTER THE DISTURBANCE PASSED SUNDAY EVENING THE RIDGE IS
FLATTENED INTO THE DESERT SW TODAY. A CLOSED LOW OFF THE
CALIFORNIA COAST PUSHES ONSHORE BY TUESDAY. THIS PATTERN WILL
BRING A DOWNTURN IN SHOWERS TODAY BUT ANOTHER SURGE ON TUESDAY.

TODAY...W-NW FLOW ALOFT HAS BROUGHT IN SLIGHTLY DRIER AIR WITH
PRECIP WATER VALUES BETWEEN 0.75 AND 1.0 INCH. THIS IS ONLY DRY IN
RELATION TO THE NEAR RECORD MOISTURE AMOUNTS WE HAD OVER THE
WEEKEND. ISOLATED MORNING SHOWERS AND STORMS WILL BECOME SCATTERED
THIS AFTERNOON FAVORING THE MOUNTAINS AND SOUTHERN VALLEYS WHERE
MOISTURE IS DEEPEST. TEMPERATURES WILL RECOVER CLOSER TO NORMAL
THIS AFTERNOON...STILL NICELY COOLER THAN THE HOT CONDITIONS OF
LAST WEEK.

TONIGHT...WEAK DISTURBANCES ARE RESOLVED DIFFERENTLY IN THE MODELS
BUT HINT AT WEAK FORCING THAT MAY KEEP A FEW STORMS GOING THROUGH
THE NIGHT. NO PORTION OF THE FORECAST AREA LOOKS FAVORED FOR
SHOWERS.

TUESDAY...AS THE LOW PUSHES TOWARDS THE CALIFORNIA COAST THE SW
RIDGE WEAKENS. FLOW TURNS TO WSW AND ALLOWS DEEPER MOISTURE TO
BEGIN TO RETURN. A MORE ORGANIZED DISTURBANCE LIFTS INTO SE UTAH
THROUGH THE AFTERNOON. STORM COVERAGE WILL INCREASE FROM SW TO NE
THROUGH THE DAY. DAYTIME TEMPERATURES TAKE ANOTHER DIP UNDER
CLOUDS AND SHOWERS.

.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 337 AM MDT MON JUL 6 2015

MONSOONAL FLOW REALLY KICKS IN TUESDAY EVENING AS CYCLONIC FLOW
FROM THE CLOSED LOW OFF THE CALIFORNIA COAST AND ANTI-CYCLONIC
FLOW FROM THE HIGH PRESSURE OVER THE GULF COAST MEET OVER MEXICO
AND KEEP MOISTURE STREAMING INTO THE AREA. GRANTED...PWATS ARE A
BIT LOWER THAN SEEN IN RECENT DAYS BUT VALUES AROUND 1 INCH STILL
MERIT ATTENTION. MODELS AGREE THAT THE CONVECTION THAT FIRED
EARLIER TUESDAY WILL CONTINUE THROUGH THE EVENING AND POSSIBLY
PAST MIDNIGHT AS A SHORTWAVE MOVES OVERHEAD. OBVIOUSLY...CHANCES
FOR HEAVY RAIN CONTINUE AS WELL.

CONVECTION CONTINUES WEDNESDAY BUT AS THE LOW APPROACHES...A
DEFORMATION ZONE SETS UP OVER THE NRN HALF OF THE AREA WHICH WILL
BE THE FOCUS FOR PRECIP THROUGH THURSDAY EVENING. BY THIS
TIME...NAM12 LOWERS PWATS AS STREAM OF MOISTURE SLOWLY SHUTS OFF
WHILE GFS KEEPS THE PLUME IN FULL FORCE. LEANING TOWARDS NAM12 AS
FORECAST PWATS FROM BOTH MODELS DO DECREASE THURSDAY AND HEIGHT
RISES INDICATE HIGH PRESSURE BUILDING IN FROM THE SOUTHEAST...ALSO
ANOTHER REASON THAT MOISTURE SLOWLY SHUTS OFF.

BY FRIDAY...THE CLOSED LOW RAPIDLY OPENS UP AND WEAKENS AS IT
BECOMES AN OPEN WAVE. THE HIGH TO THE SOUTHEAST ALSO CONTINUES TO
BUILD IN TO THE AREA SO WE CAN EXPECT CONVECTION FAVORING HIGHER
TERRAIN THOUGH COVERAGE SHOULD BE LESS THAN SEEN OVER THE LAST FEW
DAYS. SATURDAY AND SUNDAY...THE CENTER OF HIGH PRESSURE WILL HAVE
RETROGRADED AND SET UP OVER NEW MEXICO. THIS LOCATION WILL EFFECTIVELY
CUT OFF THE MOISTURE FROM THE SOUTH. A FEW ISOLATED SHOWERS
POSSIBLE BUT NOTHING OF GREAT IMPORT.

CLOUDS AND PRECIP WILL CONTINUE TO KEEP TEMPS BELOW CLIMO THOUGH A
RETURN TO MORE NORMAL VALUES EXPECTED SATURDAY AND BEYOND.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1105 AM MDT MON JUL 6 2015

EXPECT SHOWERS AND THUNDERSTORMS TO INCREASE THIS AFTERNOON AS
RISING TEMPERATURES FURTHER DESTABILIZE THE ATMOSPHERE. THESE
STORMS WILL BE LARGELY CONFINED TO HIGHER TERRAIN MOVING FROM
NORTHWEST TO SOUTHEAST WITH A FEW STORMS MOVING OVER ADJACENT
VALLEYS. AIRPORTS EAST OF A KCAG-KRIL-KDRO LINE FACE A 25 TO 35
PERCENT CHANCE OF THUNDERSTORMS MOVING OVER THEIR RUNWAYS WITH 10
TO 20 PERCENT PROBABILITIES WEST OF THE LINE. THESE STORMS MAY
LOWER CIGS BRIEFLY BELOW ILS BREAKPOINTS WITH VSBY POSSIBLY
LOWERING TO MVFR CRITERIA IN HEAVY RAIN. UNPREDICTABLE AND STRONG
OUTFLOW WINDS ARE MORE LIKELY TO IMPACT AIRPORT OPERATIONS WITH
WIND GUSTS AS HIGH AS 40 MPH. SHOWERS AND THUNDERSTORMS DECREASE
THIS EVENING BUT WON/T DIMINISH ENTIRELY AS A WEAK DISTURBANCE
MOVES OVERHEAD.

&&

.GJT WATCHES/WARNINGS/ADVISORIES...

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

&&

$$

SHORT TERM...JOE
LONG TERM...TGR
AVIATION...NL



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