Area Forecast Discussion
Issued by NWS Grand Junction, CO

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000
FXUS65 KGJT 072249
AFDGJT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND JUNCTION CO
449 PM MDT MON JUL 7 2014

.SHORT TERM...(TONIGHT THROUGH TUESDAY NIGHT)
ISSUED AT 332 PM MDT MON JUL 7 2014

H5 ANALYSIS AT 12Z PLACED A LARGE CYCLONIC GYRE OVER EASTERN
CANADA WITH THE SOUTHERN EDGE STRETCHED ACROSS THE GREAT LAKES AND
NEW ENGLAND. THIS TROUGH CONTINUES TO HOLD THE SUB TROPICAL HIGH
BACK OVER THE INTERMOUNTAIN WEST...DIRECTING THE BETTER MONSOONAL
MOISTURE ACROSS ARIZONA AND SOUTHERN NEVADA. IN OUR AREA PWAT
CONTINUES TO HOVER AROUND 3/4 OF AN INCH OR RIGHT ON THE
CLIMATOLOGICAL NORM FOR EARLY JULY. CONVECTION HAS FIRED AGAIN BUT
SHEAR ALOFT IS QUITE WEAK BEING CLOSER TO THE RIDGE AXIS AND
STORMS ARE A BIT MORE RELUCTANT TO MOVE OFF THE TERRAIN. A FEW
OUTFLOW BOUNDARIES ARE BECOMING APPARENT AND WINDS WILL MOST
LIKELY BE THE MAIN THREAT THROUGH EARLY EVENING. AGAIN THE MAIN
FOCUS WILL BE ACROSS THE SOUTHERN CWA WITH MUCH DRIER AIR LOCATED
ACROSS NORTHERN UTAH AND COLORADO.

A STRONGER SYSTEM ROTATING THROUGH MANITOBA INTO THE GREAT LAKES THE
NEXT 24 HOURS LOOKS TO PUSH A FRONT DOWN THE HIGH PLAINS
OVERNIGHT..THEN ALLOW THE WESTERN RIDGE AXIS TO BECOMING A BIT MORE
NORTH TO SOUTH ORIENTED AS IT PUSHES INTO THE GREAT LAKES TOMORROW.
STILL THE MAIN MOISTURE PLUME WILL HELD BACK TO OUR WEST BUT UPPER
LEVEL WINDS WILL INCREASE JUST A TAD FROM THE NORTHWEST. THIS SHEAR
MAY BE JUST ENOUGH TO KEEP STORM MORE ORGANIZED AND ALLOW THEM TO
SURVIVE INTO VALLEY LOCATIONS. THE MODELS ARE ONCE AGAIN FAVORING
THE SOUTHERN CWA WHERE THE PERSISTENT SHEAR AND RESIDUAL MOISTURE
AXIS RESIDES. THERE MAY ALSO BE ADDITIONAL MOISTURE PUSHING IN
FROM THE EAST AS HIGH PRESSURE BUILDS ALONG THE FRONT RANGE.
SCATTERED AFTERNOON POPS LOOK ON TRACK WITH SOME HIGH CHANCES IN
THE EASTERN SAN JUANS AND ELKS. GENERALLY ISOLATED IN THE SOUTHERN
VALLEYS. GUIDANCE NUMBERS CONTINUE TO COOL HIGHS DOWN A FEW
DEGREES FOR TUESDAY AND CURRENT FORECAST ON TRACK SO ONLY MINOR
TWEAKS. THE UPPER RIDGE SCOOTS RIGHT OVER THE CWA TUESDAY NIGHT.
FORCING IS WEAK BUT MOISTURE WILL BEGIN TO INCREASE THE SHIFT.
FOR THE MOST PART EXPECT STORMS TO ABATE AFTER SUNSET...BUT SOME
NOCTURNAL SHOWERS MAY STICK AROUND IN THE SOUTH THROUGH SUNRISE.

.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 332 PM MDT MON JUL 7 2014

THE SUB-TROPICAL HIGH REMAINS IN CONTROL THROUGH THE LONG TERM.
WEDNESDAY THROUGH THURSDAY THE 591 RIDGE CENTER GETS NUDGED EAST
TO ALONG OR JUST EAST OF THE CONTINENTAL DIVIDE. THIS ALLOWS THE
DEEP MOISTURE CURRENTLY POOLED TO THE SW TO WORK INTO THIS
FORECAST AREA. PWAT VALUES CLIMB OVER ONE INCH WITH THE THETA-E
RIDGE ORIENTED FROM DURANGO NORTH TO GLENWOOD SPRINGS. THEREFORE
EXPECT AN INCREASE IN SHOWERS AND THUNDERSTORMS ACROSS THE REGION
ON WEDNESDAY WITH SOME STORMS CONTINUING THROUGH THE NIGHT.
WETTING RAINS ARE POSSIBLE WITH HEAVY SHOWERS POSSIBLE IN SE UTAH
AND SW COLORADO. GUSTY WINDS MAY BE WIDESPREAD BY LATE IN THE DAY
AND INTO THE EVENING. DAYTIME TEMPERATURES WILL DROP BACK TO NEAR
NORMAL IN CLOUDS AND SHOWERS.

THURSDAY A PACIFIC WAVE WORKS NE THROUGH THE WESTERN GREAT BASIN
THAT MAY PROVIDE A CONTINUATION OF INCREASED STORM ACTIVITY. THE
GFS ADVECTS IN DRIER AIR WITH THIS SYSTEM BUT THE NAM AND EC
REMAIN WET.

THEN BEGINNING FRIDAY THE RIDGE AMPLIFIES FROM THE FOUR CORNERS NW
INTO BRITISH COLUMBIA WITH HEIGHTS CLIMBING TO AROUND 595 DAM OVER
THE WEEKEND. INCREASED SUBSIDENCE AND A LESS DIRECT ACCESS TO
MOISTURE WILL KEEP A LOW-GRADE MONSOON PATTERN ALONG WITH DAYTIME
TEMPERATURES ABOVE NORMAL.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 449 PM MDT MON JUL 7 2014

ISOLD TO SCT -TSRA/-SHRA WILL CONTINUE MAINLY SOUTH OF I-70 UNTIL
02Z-03Z THEN ISOLD -SHRA/-TSRA UNTIL ABOUT 07Z...SIMILAR TO THE
PAST FEW DAYS. THE HIGH-BASED STORMS WILL SLOWLY DRIFT SOUTHWARD
AND REMAIN CAPABLE OF ERRATIC OUTFLOW WINDS OF 30KTS...POSSIBLY
40KTS FROM THE STRONGER STORMS. LITTLE CHANGE FOR TUE EXCEPT FOR
A BIT MORE STORM COVERAGE OVER THE CENTRAL AND SOUTHERN CO MTNS
18Z-24Z TUE AFTERNOON.

&&

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

$$

SHORT TERM...15
LONG TERM...JOE
AVIATION...JAD



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