Area Forecast Discussion
Issued by NWS Grand Junction, CO

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
000
FXUS65 KGJT 311018
AFDGJT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND JUNCTION CO
418 AM MDT THU JUL 31 2014

.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 417 AM MDT THU JUL 31 2014

MORNING LOW TEMPERATURES FLIRTING WITH RECORDS AS GRAND JUNCTION
HAS A RATHER MILD JULY 31ST RECORD LOW OF 58 SET IN 1909 AND
SITTING AT 60 AS OF 4 AM THIS MORNING. STILL A FEW HOURS OF
COOLING TO GO...SO A NEW RECORD COULD BE HIT. AFTER THE COOL START
TO THE DAY...AFTERNOON MAX TEMPS EXPECTED TO REMAIN A GOOD 10
DEGREES BELOW NORMAL FOR MOST LOCATIONS.

FOCUS OF CONVECTION SHIFTS TO OUR SOUTHERN ZONES TODAY WITH ACTIVITY
FIRING OVER THE SAN JUAN MOUNTAINS BY LATE MORNING AND THEN
SPREADING OVER INTO THE VALLEYS THIS AFTERNOON AND EVENING. PLENTY
OF MOISTURE STILL IN PLACE WITH PRECIPITABLE WATER VALUES OVER AN
INCH. SO EXPECT LOCALLY HEAVY RAINFALL AND POTENTIAL FOR MORE MUD
SLIDES NEAR STEEP TERRAIN. CONVECTION WILL BE A BIT MORE ISOLATED
ACROSS OUR NORTHERN ZONES WITH SUBTLE DRYING BEHIND WEAK WAVE THAT
PASSED LAST EVENING.

DUE TO A SOMEWHAT DRIER AIR MASS...THE AFTERNOON`S CONVECTION WILL
DIMINISH BY LATE IN THE EVENING. ANY LINGERING NOCTURNAL ACTIVITY
LIMITED TO THE SOUTHEAST CORNER OF THE FORECAST AREA WHERE
PRECIPITABLE WATER VALUES WILL STILL BE NEARLY AN INCH.

AN EMBEDDED DISTURBANCE TRAVELING FROM THE CENTRAL CA COAST WILL
PASS OVER THE NORTHERN HALF OF THE FORECAST AREA ON FRIDAY. THIS
WILL PROVIDE AN ADDITIONAL BOOST TO THE DAYTIME INSTABILITY.
HOWEVER THE MORE UNSTABLE NORTH WILL ALSO BE THE DRIEST PORTION OF
THE FORECAST AREA. PRECIPITABLE WATER THERE DROPS TO ALMOST HALF
AN INCH...BUT STAYS CLOSER TO AN INCH ALONG OUR SOUTHERN EDGE. SO
WHILE THE NORTH IS IN A BETTER POSITION FOR THE DISTURBANCE...THE
SOUTH HAS THE BETTER MOISTURE. THEREFORE EXPECT WE WILL AGAIN SEE
SHOWERS AND THUNDERSTORMS DEVELOP DURING THE AFTERNOON...MAINLY
OVER THE HIGHER TERRAIN. HEAVY RAIN WILL NOT BE AS LIKELY DUE TO
THE LESS AVAILABLE MOISTURE. AND DO NOT EXPECT THE RAIN PRODUCTION
TO BE QUITE AS EFFICIENT AS IT HAS BEEN THE PAST COUPLE OF DAYS.
ALSO THE FLOW WILL BE FROM THE WEST-NORTHWEST AT AROUND 15 KTS IN
THE SOUTH...ADEQUATE TO KEEP THE STORMS MOVING ALONG. THE FLOW
WILL BE A LITTLE LIGHTER UP NORTH...BUT ALSO THAT AREA WILL BE
DRIER.

LOW TEMPERATURES WILL BE NEAR NORMAL...WITH HIGHS STAYING A LITTLE
BELOW NORMAL FOR THIS TIME OF YEAR.

.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 417 AM MDT THU JUL 31 2014

MOISTURE CONTINUES TO DIMINISH ON SATURDAY WITH PRECIPITABLE
WATER DROPPING BELOW HALF AN INCH OVER A LARGE SECTION OF THE
FORECAST AREA. THEREFORE LOOK FOR A DOWN TURN IN THE AFTERNOON
SHOWER AND THUNDERSTORM ACTIVITY. WITH LESS CLOUDS AND
SHOWERS...TEMPERATURES WILL CLIMB TO AROUND NORMAL.

RIDGE AXIS SLIDES BACK INTO THE PLAINS BY EARLY NEXT WEEK OPENING
THE GATES BACK UP FOR ANOTHER SURGE OF DEEPER MONSOONAL MOISTURE.
MODELS HINTING AT A STRONGER WAVE LIFTING NORTH ACROSS THE FOUR
CORNERS LATE SUNDAY...WITH A SECOND STRONGER WAVE FOLLOWING LATE
MONDAY NIGHT AND TUESDAY. THIS SECOND WAVE LOOKS TO SWEEP THE
DEEPER MOISTURE OUT INTO THE PLAINS BY THE MIDDLE OF NEXT WEEK
WITH RIDGING REBUILDING TO OUR WEST. THIS WOULD BRING DRIER NWLY
FLOW INTO THE FORECAST AREA BY WEDNESDAY. TEMPS EXPECTED TO REMAIN
NEAR SEASONAL NORMS THROUGH THE LATER PERIODS OF THE EXTENDED.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 417 AM MDT THU JUL 31 2014

SCATTERED SHOWERS AND THUNDERSTORMS...MOST NUMEROUS OF THE SAN
JUAN MOUNTAINS...WILL DEVELOP BY 18Z. INITIALLY...STORMS WILL BE
CONFINED TO THE HIGHER MOUNTAINS...BUT THEY ARE EXPECTED TO SLIDE
OVER THE VALLEYS BY MID-AFTERNOON. EXPECT HEAVY RAIN AND GUSTY
WINDS TO 40 MPH. HIGH VALLEY TAF SITES...SUCH AS KASE AND KEGE
WILL SEE A 40 PERCENT CHANCE OF THUNDERSTORMS...WITH LOWER
VALLEYS RUNNING AROUND 20 PERCENT. CONVECTION DIMINISHES AFTER 06Z
THIS EVENING.

&&

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

$$

SHORT TERM...JDC/EH
LONG TERM...EH/JDC
AVIATION...JDC



USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.