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 291812
AFDGJT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND JUNCTION CO
1212 PM MDT MON JUN 29 2015

.UPDATE...
ISSUED AT 1150 AM MDT MON JUN 29 2015

THE RIDGE OVER UTAH IS IN CONTROL AND WILL LIMIT CONVECTIVE UPDRAFT
STRENGTH THIS AFTERNOON. BUT MOISTURE IS ABOVE NORMAL WITH PRECIP
WATER VALUES AT 0.83 INCH ON THE MORNING BALLOON RELEASE HERE AT
GRAND JUNCTION. THE DCAPE VALUE IS AT 1335 J/KG...AN INDICATOR OF
STRONG DOWNDRAFTS AND THUS STRONG AND GUSTY OUTFLOW WINDS.
MOISTURE IS GREATER IN THE SOUTHEAST SAN JUANS AND SUBSIDENCE
THERE IS WEAKER. SO PAGOSA SPRINGS TO LAKE CITY IS THE FAVORED
AREA FOR THUNDERSTORM COVERAGE. SOME STORMS PRODUCE SMALL HAIL AND
VERY STRONG WINDS GUSTS. NE UTAH AND FAR NW COLORADO WILL SEE
LITTLE TO NO THUNDERSTORM COVERAGE THIS AFTERNOON.

TONIGHT A FEW SHOWERS COULD PERSIST OVER THE SOUTHERN MOUNTAINS
UNTIL MIDNIGHT. OTHERWISE OVERNIGHT LOW TEMPERATURES WILL
GENERALLY BE SOME 10 DEGREES ABOVE NORMAL EXCEPT NEAR NORMAL
ACORSS THE NORTH.

&&

.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 340 AM MDT MON JUN 29 2015

OVER THE LAST 24 HOURS THERE HAS BEEN AN EVER SO GRADUAL INCREASE
IN AVAILABLE MOISTURE AS SEEN ON THE GJT SOUNDINGS. THE GREAT
BASIN HIGH PRESSURE WILL CONTINUE TO REMAIN STATIONARY OVER THE
NEXT 48 HOURS KEEPING EASTERN UTAH AND WESTERN COLORADO IN LIGHT
NORTHERLY FLOW. MODELS INDICATE A BIT MORE MOISTURE LEAKING IN
FROM THE SOUTH TODAY UNDER THE LIGHT FLOW REGIME. 500J/KG CAPE
VALUES TODAY ARE PRETTY WIDESPREAD WHICH IS NOT SIGNIFICANT BUT
MAY BE INDICATING MORE COVERAGE IN SHOWER AND THUNDERSTORM
ACTIVITY TODAY. DURING THE LATE DAY TUESDAY IS FORECAST TO BE SIMILAR
BUT MORE FOCUSED TOWARD THE SAN JUANS AGAIN.

TEMPS WILL ONCE AGAIN BE NEAR OR ABOVE TRIPLE DIGITS IN THE
DESERT VALLEYS. ONCE AGAIN ADJUSTED MIN TEMPS AS THESE WERE
RUNNING WAY TOO HIGH IN MOST LOCATIONS...ESPECIALLY THE NORTHERN
VALLEYS OF NE UT AND NW CO.

.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 340 AM MDT MON JUN 29 2015

MOISTURE WILL CONTINUE TO CIRCULATE AROUND AND INCREASE WITHIN
RELATIVELY STATIONARY HIGH PRESSURE OVER THE WESTERN U.S.  EASTERN
UT AND WESTERN CO WILL REMAIN OVER THE N TO NW FLOW ALONG THE
EASTERN PERIPHERY OF THE RIDGE. THIS MOISTURE ALONG WITH CONTINUED
HOT CONDITIONS AND ABUNDANT DAYTIME HEATING WILL ALLOW HIGH BASED
THUNDERSTORMS TO FORM EACH AFTERNOON AND EVENING...MAINLY OVER
THE MOUNTAINS AND EAST OF A LINE FROM CRAIG TO RIFLE TO DURANGO.
THESE STORMS WILL GRADUALLY INCREASE THE LOWER LEVEL MOISTURE EACH
DAY...WITH AN INCREMENTAL INCREASE IN AREAL COVERAGE AND THE
AMOUNT OF RAIN ACTUALLY REACHING THE GROUND.

WEDNESDAY AND THURSDAY...A FEW DISTURBANCES WILL RIDE DOWN THE
FRONT RANGE CAUSING THE RIDGE TO SLIDE A BIT FURTHER WEST. THIS
SHOULD CAUSE NE UT AND NW CO TO BECOME DRIER...BUT ALLOW MORE
MOISTURE TO REACH SW CO.

FRIDAY THROUGH SUNDAY DRIER CONDITIONS SHOULD PREVAIL UNDER DRIER
NW FLOW ALOFT.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY NOON)
ISSUED AT 1150 AM MDT MON JUN 29 2015

VFR CONDITIONS WILL PREVAIL THROUGH TUESDAY. ISOLATED TO
SCATTERED THUNDERSTORMS WILL FORM MAINLY OVER THE SOUTHERN AND
CENTRAL MOUNTAINS THROUGH 02Z THIS EVENING. KMTJ KTEX KDRO HAVE A
30 PERCENT POTENTIAL FOR THUNDERSHOWERS... A 10 PERCENT CHANCE IN
KASE KEGE. THE MAIN THREAT IS OUTFLOW WIND GUSTS UP 45 KTS.

&&

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

$$

UPDATE...JOE
SHORT TERM...JAM
LONG TERM...CC
AVIATION...JOE



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