Area Forecast Discussion
Issued by NWS Grand Junction, CO

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FXUS65 KGJT 200517
AFDGJT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND JUNCTION CO
1117 PM MDT SUN OCT 19 2014

.UPDATE...
ISSUED AT 913 PM MDT SUN OCT 19 2014

LATE DAY CONVECTION FINALLY DYING OFF...BUT STILL ENOUGH WEAK
MUCAPE ALONG WITH AXIS OF 0.6 TO 0.7 INCH PRECIP WATER OVER THE
SAN JUAN MTNS TO KEEP WEAK CONVECTION ALIVE. THIS WILL CONTINUE
THROUGH ABOUT MIDNIGHT...THEN SHOULD SHUT OFF AS ATMOSPHERE
STABILIZES. OTHERWISE...A QUIET NIGHT IN STORE. HAVE MADE SLIGHT
ADJUSTMENTS TO THE OVERNIGHT CHANCE OF PRECIP TO FOLLOW CURRENT
TRENDS.

&&

.SHORT TERM...(TONIGHT THROUGH MONDAY NIGHT)
ISSUED AT 310 PM MDT SUN OCT 19 2014

NO SURPRISES TODAY WITH THE WEATHER...AS EXPECTED THE SAN JUAN
MOUNTAINS HAVE BEEN THE BULLSEYE OF ACTIVITY WITH SCATTERED
SHOWERS AND ISOLATED TSTORMS TO CONTINUE THROUGH THE EVENING. THE
HRRR AND RAP13 INDICATE SHOWERS CONTINUING OVER THE SAN JUAN
MOUNTAINS UNTIL AROUND 6PM TONIGHT AND CONTINUING OVER THE CENTRAL
DIVIDE THROUGH ABOUT 9PM. WOULDN/T BE SURPRISED IF A SHOWER OR TWO
LINGERS THROUGH MIDNIGHT.

SIMILAR SHOWER ACTIVITY IS EXPECTED AGAIN ON MONDAY AS THE
FORECAST AREA REMAINS IN SOUTHERLY FLOW BETWEEN HIGH PRESSURE TO
THE EAST AND WEAK CYCLONIC FORCING TO THE SOUTH. CONVECTIVE
INDICES SHOW A LESSER CHANCE FOR TSTORMS...BUT CONVECTIVE CELLS
WILL STILL BE CAPABLE OF MODERATE TO HEAVY RAIN SHOWERS AND GUSTY
WINDS. THESE WILL ONCE AGAIN BE MOST LIKELY OVER THE SAN JUANS BUT
MAY MAKE IT TO OTHER MOUNTAINOUS REGIONS OF THE FORECAST AREA AS
PRECIPITABLE WATER INCREASES SLIGHTLY.

TEMPERATURES WILL REMAIN 5 TO 10 DEGREES ABOVE NORMAL OVER THE
NEXT COUPLE OF DAYS.

.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 310 PM MDT SUN OCT 19 2014

MODELS ARE ON TRACK IN BRINGING THE APPROACHING PACIFIC SHORTWAVE
ACROSS THE GREAT BASIN EARLY TUE...THEN EJECTING IT TO THE
NORTHEAST INTO WY BY TUE NIGHT. AN ASSOCIATED COLD FRONT WILL
REACH THE NORTHWEST AND WEST EDGES BY AROUND MIDDAY...THEN WEAKEN
AS IT MOVES ACROSS THE FORECAST AREA AS THE BEST FRONTAL FORCING
STAYS TO OUR NORTH. ALSO THE BEST ENERGY/COLDEST AIR ASSOCIATED
WITH THE UPPER TROUGH WILL STAY TO OUR NORTHWEST THEN NORTH...
SOMEWHAT LIMITING THE IMPACT ON OUR FORECAST AREA. HOWEVER ON THE
PLUS SIDE...MOISTURE WILL CONTINUE TO STREAM UP FROM THE SOUTH ON
THE SOUTHWEST FLOW AHEAD OF THE TROUGH...PEAKING AT AROUND 6 G/KG
SPECIFIC HUMIDITY FROM EARLY TUE INTO THE EVENING. ALSO THE TIMING
OF THE UPPER WAVE AND SURFACE FRONT WILL BE OPTIMAL TO TAKE
ADVANTAGE OF DAYTIME HEATING. THE TAIL/RIGHT ENTRANCE REGION OF
THE UPPER JET WILL ALSO BRUSH THE FORECAST AREA TUE MIDDAY-
AFTERNOON FOR A LITTLE BIT OF A BOOST.

THEREFORE EXPECT SHOWERS TO INCREASE TUE MORNING...WITH THE
CHANCE FOR THUNDERSTORMS IN THE AFTERNOON. ACTIVITY WILL CONTINUE
TUE NIGHT AND WED AS THE UPPER TROUGH AXIS PASSES OVER THE AREA.
BUT EXPECT THAT TUE AFTERNOON/EARLY EVENING WILL SEE THE BEST
PRECIPITATION DUE TO THE BETTER INSTABILITY...AND OTHER
INGREDIENTS COMING TOGETHER AT THAT TIME. BY TUE EVENING ACTIVITY
WILL BEGIN TO DIMINISH OVER THE FAR WEST AS A DRIER WEST...THEN
NORTHWEST FLOW DEVELOPS. AS THIS HAPPENS...THE COLORADO DIVIDE
WILL BECOME FAVORED...WITH THE NORTHERN DIVIDE HOLDING ONTO
SHOWERS THE LONGEST. THIS SYSTEM NOT OVERLY COLD...BUT SNOW
LEVELS SHOULD LOWER TO AROUND 9KFT TUESDAY NIGHT WITH LIGHT SNOW
ACCUMULATIONS EXPECTED IN THE HIGHER COLORADO MTN RANGES.

COOLER TEMPS ARE EXPECTED ON TUE DUE TO THE INCREASED
CLOUDS/SHOWERS...WITH SIMILAR TEMPERATURES ON WED. WED NIGHT WILL
SEE THE COOLEST LOWS. BUT IT LOOKS LIKE AREAS THAT STILL HAVE NOT
HAD A SEASON ENDING FREEZE WILL REMAIN SAFE AND STAY ABOVE
FREEZING BEHIND THIS SYSTEM.

A WARMING AND DRYING TREND WILL DEVELOP ON THURSDAY AS HIGH
PRESSURE BUILDS OVER THE REGION. THIS WILL CONTINUE INTO THE
WEEKEND WITH A RETURN TO THE VERY WARM TEMPERATURES...WELL ABOVE
NORMAL FOR THIS TIME OF YEAR. LATE IN THE PERIOD THE GFS BRINGS
THE NEXT UPPER TROUGH TO OUR DOORSTEP ON SUNDAY. HOWEVER THE
ECMWF...IS ABOUT 24 HOURS LATER.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1112 PM MDT SUN OCT 19 2014

SOME LINGERING CLOUDS AND VERY ISOLATED SHOWERS PERSIST TONIGHT
OVER THE SAN JUANS BUT SHOULD SCATTER OUT VERY SHORTLY BECOMING
MOSTLY CLEAR. AS FAR AS TOMORROW IS CONCERNED...EXPECT SIMILAR
CONDITIONS LIKE TODAY WITH SOME SHOWERS AND STORMS POSSIBLE OVER
THE SAN JUANS AND CENTRAL MOUNTAINS. TAF SITES WHICH MAY BE
AFFECTED INCLUDE KTEX...KASE...AND KDRO FROM 18Z THROUGH 00Z. HAVE
LEFT MENTION OF PRECIP OUT OF ALL TAFS EXCEPT FOR KTEX WHICH IS IN
AN IDEAL LOCATION TO SEE SOME SHOWERS.

&&

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

$$

UPDATE...BEN
SHORT TERM...JAM
LONG TERM...EH
AVIATION...TGR



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