FXUS65 KGJT 312110 CCA

AFDGJT



AREA FORECAST DISCUSSION...CORRECTED

NATIONAL WEATHER SERVICE GRAND JUNCTION CO

250 PM MDT SAT JUL 31 2010



CORRECTED LONG TERM SECTION TO ADD MISSING WORDS



.SHORT TERM...TODAY THROUGH MONDAY...

SUBTROPICAL HIGH IS IN THE PROCESS OF REPOSITIONING ITSELF EAST OF

COLORADO.  THIS WILL ALLOW LIGHT SOUTHERLY FLOW TO SPREAD NORTH

ACROSS THE ENTIRE FORECAST AREA THIS EVENING.  EASTERLY WAVE OVER

ERN NEW MEXICO IS PROGGED TO APPROACH SW COLORADO TONIGHT AND THEN

SHEAR NORTHEAST ACROSS THIS AREA SUNDAY NIGHT.  THIS KEEPS THE

MONSOONAL PLUME LOCKED ACROSS THE FORECAST AREA...BUT IT WILL

EXPAND NORTHWARD GIVEN THE LIGHT SOUTHERLY FLOW.  THE AIR MASS

ENVIRONMENT REMAINS SIMILAR WITH SLOW MOVING CELLS...SO WILL GO

AHEAD AND ISSUE ANOTHER FLASH FLOOD WATCH ON SUNDAY BUT EXPAND IT

NORTHWARD TO INCLUDE THE GRAND VALLEY...TAVAPUTS AND BOOKCLIFF

AREAS.



MONDAY...MONSOONAL PLUME TAKES A SOUTHWEST TO NORTHEAST ORIENTATION

AS A PACIFIC NORTHWEST TROUGH SKIRTS INLAND.  THIS BRINGS DRIER AIR

TOWARD THE WYOMING BORDER...OTHERWISE THE AIR MASS KEEPS IT MONSOONAL

ENVIRONMENT.  A STRONGER EASTERLY WAVE WILL BE APPROACHING THE FOUR

CORNERS AREA MONDAY EVENING...POSSIBLY ENHANCING CONVECTION FOR THE

SRN AREAS.



.LONG TERM...MONDAY NIGHT THROUGH SATURDAY...



APPEARS THE FORECAST AREA COULD STAY IN AN UNSETTLED AND WET PATTERN

THROUGH AT LEAST MIDWEEK. THE EXPECTED LARGE-SCALE PATTERN IS FOR A

GRADUALLY AMPLIFYING WEST COAST TROUGH...WITH THE PERSISTENT BROAD

HIGH PRESSURE CENTERED OVER THE SOUTH CENTRAL PORTION OF THE

COUNTRY. SOUTHERLY FLOW BETWEEN THE TWO SHOULD KEEP THE SUBTROPICAL

MOISTURE PLUME ACROSS THE 4 CORNERS AND HELP GUIDE SEVERAL EMBEDDED

DISTURBANCES THROUGH THE AREA. STRONGER ONE LOOKS TO MOVE NE ACROSS

THE AREA WED. PAC NW TROUGH ALSO EJECTS A WAVE ACROSS ID MONDAY

NIGHT-TUESDAY THAT MAY INTERACT WITH THE NORTHERN REACHES OF THE

MOISTURE. MODELS SHOW A GRADUAL DECREASE IN MOISTURE/POPS FROM THE

WEST AND NORTHWEST LATE IN THE WEEK...BUT HAVE SOME DOUBTS WITH THE

GFS HOLDING ONTO SOME WEST COAST TROUGHING. MAIN CHANGE TO THE 

FORECAST WAS TO BOOST THE CHANCE OF PRECIP FOR TUE-WED. WEAK 700 MB 

WINDS TUE-WED WILL KEEP THE THREAT OF SLOW MOVING STORMS AND HEAVY 

RAIN PRESENT. FLOW ALOFT THEN SHOWN TO STRENGTHEN BY FRI FOR FASTER 

MOVING STORMS LATE IN THE WEEK.



&&



.AVIATION...



THE PERSISTENT PATTERN OF AFTERNOON SHOWERS AND THUNDERSTORMS 

LINGERING WELL INTO THE EVENING...WILL CONTINUE INTO MONDAY. STORM 

ACTIVITY WILL BE MORE NUMEROUS ACROSS THE SOUTHERN MOUNTAINS WITH 

SCATTERED STORMS NORTH OF THE I-70 CORRIDOR.  LOOK FOR AREAS OF MVFR 

CIGS AND VIS IN HEAVY RAIN TO RESULT IN MOUNTAIN OBSCURATIONS AFTER 

1200...CONTINUING WELL INTO THE EVENING.  POCKETS OF TORRENTIAL 

DOWNPOURS WILL RESULT IN IFR OR LIFR CIGS AND VIS.  ADDITIONAL 

HAZARDS INCLUDE OUTFLOW WINDS TO 40 MPH AND SMALL HAIL.



&&



.GJT WATCHES/WARNINGS/ADVISORIES...



CO...NONE

UT...NONE.



$$



SHORT TERM.....PF

LONG TERM......JAD

AVIATION.......NL