National Weather Service National Headquarters

• Home
• Site Map
• News
• Organization
• Search for: NWS All NOAA 

000
FXUS65 KGJT 242103
AFDGJT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND JUNCTION CO
303 PM MDT FRI MAY 24 2013

.SHORT TERM...(THIS EVENING THROUGH SATURDAY NIGHT)
ISSUED AT 302 PM MDT FRI MAY 24 2013

AFTERNOON TEMPERATURES WERE RUNNING A FEW DEGREES LESS WARM THAN ON
THURSDAY. AND THE LACK OF A PASSING DISTURBANCE TODAY HAS LOWERED
THE AFTERNOON WIND GUSTS. PERSISTENCE IS THE BEST TOOL AS HOT AND
DRY CONDITIONS CONTINUE.

TONIGHT...THE SURFACE-BASED INVERSIONS WILL BE STRONGER WITH
ENHANCED DRAINAGE WINDS PROGGED IN GUIDANCE. THIN HIGH CLOUDS BEGIN
TO INVADE FROM THE WEST

SATURDAY...THE MAIN UPPER LOW CONTINUES SPINS OVER THE PACIFIC
NORTHWEST. A SECONDARY TROUGH DROPS DOWN THE BACK SIDE OF THE LOW
AND PUSHES INTO OREGON EARLY SUNDAY. HIGH CLOUDS STILL PROGGED TO
INCREASE SATURDAY. THIS MAY SLIGHTLY MODIFY MAX TEMPERATURES AND MAY
ALSO IMPACT AFTERNOON MIXING WINDS. INVERSIONS TO SET UP QUICKLY ON
OR BEFORE SUNSET.

.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 302 PM MDT FRI MAY 24 2013

LOW PRESSURE WILL CONTINUE TO PINWHEEL ACROSS THE NORTHWEST STATES
THROUGH THE WEEKEND...KEEPING THE DRY AND WARM SOUTHWEST FLOW
POINTED IN OUR DIRECTION. THIS WILL KEEP PRECIPITATION AT BAY WITH
ONLY SOME HIGH CLOUDINESS EXPECTED TO PROGRESS ACROSS THE SKY AT
TIMES. WINDS WILL CONTINUE TO BE GUSTY IN THE
AFTERNOONS...ESPECIALLY ABOVE 9000 FEET WHICH WILL KEEP SOME THREAT
OF LOCALIZED CRITICAL FIRE WEATHER CONCERNS IN PLACE ACROSS
SOUTHWEST COLORADO. HIGHS WILL BE SIMILAR ON SUNDAY TO THOSE FOUND
THE PAST FEW DAYS...RUNNING AROUND 5 TO 10 DEGREES ABOVE
NORMAL.

SUNDAY NIGHT INTO MONDAY THE UPSTREAM LOW WILL BE FRAGMENTED BY THE
ARRIVAL OF A STRONGER WAVE MOVING THROUGH THE BASE OF THE LOW..THEN
A STRONGER UPSTREAM JET DIVING THROUGH THE NORTHEAST PACIFIC. AS
THIS JET DIVES AND NORTHERN LATITUDE ENERGY CONTINUES TO DIG INTO
THE WEST THROUGH MID WEEK...A NEGATIVELY TILTED TROF WILL SPREAD
ACROSS MUCH OF THE WEST AND BRING A COOLING TREND TO OUR REGION
THROUGH THE LATTER PART OF NEXT WEEK. THE WAVE MOVING THROUGH THE
FLOW ON MONDAY WILL SHEAR OUT TO OUR NORTH BUT SERVE TO TIGHTEN THE
PRESSURE GRADIENT ALOFT. MOISTURE WILL ALSO BEGIN TO BE ENTRAINED IN
THE SOUTHWEST FLOW AS THE SUB TROPICAL JET NOSES NORTHWARD. THIS
MOISTURE WILL BE WELL ALOFT SO DO NOT EXPECT PRECIPITATION AT THE
MOMENT...BUT THIS WILL BE CHANGING TUESDAY INTO WEDNESDAY.
MOISTURE TRANSPORT CONTINUES DURING THIS TIME...PEAKING ON WEDNESDAY
AS THE WESTERN TROF AXIS MOVES INTO THE WESTERN GREAT BASIN. THERE
WILL BE AN UPTICK IN INSTABILITY MOVING IN WITH THE MOISTURE BUT
EXPECT MINIMAL PCPN OUTPUT FROM ISOLATED STORMS ON TUESDAY...WITH
MORE A WIND THREAT DUE TO INVERTED V PROFILES. PWATS WILL PUSH UP
TOWARD A HALF OF AN INCH BY WEDNESDAY WHICH SHOULD BE USED MORE
EFFICIENTLY BE MORE ORGANIZED ASCENT AHEAD AS THE TROF PUSHED ACROSS
OUR CWA. HOWEVER MODELS THIS FAR OUT AT STILL AT ODDS ON WHETHER
THIS ENERGY WILL BE SPLITTING (GFS) OR DIGGING (EURO) SOUTH OF OUR
AREA SO CONFIDENCE IN SOME DETAILS QUITE LOW...SO POPS REMAIN IN THE
LOW CHANCE CATEGORY FOR NOW. TEMPERATURES WILL COOL BACK TO OR BELOW
NORMAL DURING THIS TROF PASSAGE...AND WITH DIFFERENCES IN MODEL
SOLUTIONS DURING THE LATE WEEK PERIOD THE WARM UP IS NOT CLEAR ATTM
AS WELL.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 302 PM MDT FRI MAY 24 2013

VFR CONDITIONS WILL PREVAIL ACROSS EASTERN UT AND WESTERN CO. GUSTY
SOUTHWEST WINDS WILL CONTINUE THROUGH 03Z THIS EVENING AND DEVELOP
AGAIN ON BEGINNING AOA 16Z SATURDAY CAUSING MECHANICAL TURBULENCE.
THE STRONGEST TURBULENCE WILL OCCUR ALONG AND NORTH OF RIDGES AND
PEAKS.

&&

.FIRE WEATHER...
ISSUED AT 302 PM MDT FRI MAY 24 2013

THE UPPER PATTERN IS FAIRLY STAGNANT AT THE MOMENT WITH LOW
ANCHORED OVER THE NORTHWEST CONUS. THIS WILL KEEP A DRY AND
WARM SOUTHWEST FLOW DIRECTED AT EASTERN UTAH AND WESTERN
COLORADO. THE AIRMASS IN PLACE WILL CONTINUE TO LEAD TO
ABOVE NORMAL TEMPERATURES...LOW AFTERNOON RELATIVE HUMIDITY
AND HIGH HAINES INDEX VALUES. WINDS ALOFT WILL GRADUALLY
BE WEAKENING HOWEVER THE NEXT FEW DAYS BEFORE PICKING UP
EARLY NEXT WEEK AS THE TROF BEGINS TO EJECT EASTWARD. CRITICAL
FIRE WEATHER CONDITIONS WILL EASE AFTER SUNSET TONIGHT THEN
RETURN FOR SATURDAY AFTERNOON AND EARLY EVENING...WITH RED
FLAG WARNINGS IN EFFECT FOR PORTIONS OF ZONES 291 AND 207
THROUGH THIS TIME. FOR SUNDAY INTO MONDAY THESE CRITICAL
CONDITIONS WILL BE MORE LOCALIZED AND CONFIDENCE IS LOW AT
THE MOMENT ADDITIONAL FIRE WATCHES...BUT THIS CONTINUE TO
BE MONITORED. AS THE TROUGH MOVES IN TOWARD THE MID WEEK
PERIOD AN INCREASE IN THE WINDS AND HIGH LEVEL MOISTURE
MAY LEAD TO MORE FIRE WEATHER ISSUES INCLUDING DRY
THUNDERSTORM ACTIVITY. COOLER CONDITIONS ARE EXPECTED
THROUGH THE LATE WEEK PERIOD.

&&

.GJT WATCHES/WARNINGS/ADVISORIES...
CO...RED FLAG WARNING UNTIL 9 PM MDT THIS EVENING FOR COZ207-291.

     RED FLAG WARNING FROM NOON TO 9 PM MDT SATURDAY FOR COZ207-291.

UT...NONE.
&&

$$

SHORT TERM...JOE
LONG TERM...15
AVIATION...15
FIRE WEATHER...15