Area Forecast Discussion Issued by NWS Grand Junction, CO
000
FXUS65 KGJT 140844
AFDGJT
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND JUNCTION CO
244 AM MDT FRI JUN 14 2013
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 242 AM MDT FRI JUN 14 2013
IR SATELLITE IMAGERY SHOWING WARMING CLOUDS OVER THE SAN JUANS
THIS MORNING WHILE RADAR MOSAIC SHOWS SOME LINGERING ECHOES SO
EXPECT SHOWERY PRECIP WILL CONTINUE OVERNIGHT. WATER VAPOR
IMAGERY SHOWS DRY INTRUSION HAVING ALREADY ENTERED OUR CWA AND
THIS WILL CONTINUE THROUGH THE DAY TODAY. THE TROUGH RESPONSIBLE
FOR THE WINDS AND PRECIP YESTERDAY HAS LIFTED NORTHWARD THOUGH THE
ASSOD COOLER PUSH OF AIR IS STILL EVIDENT AT THE H7 LEVEL AND ALSO
THICKNESSES. APPEARS THIS COOL FRONT WILL STALL NEAR I-70 OR A
LITTLE SOUTH BEFORE WASHING OUT. WHAT THIS MEANS IS PLENTY OF
SUNSHINE AND WARM TEMPERATURES...THOUGH SEVERAL DEGREES COOLER
THAN YESTERDAY...WITH MUCH LESS WIND. PREVIOUS MODEL RUNS
HIGHLIGHTED SOME QPF OVER THE SAN JUANS AND LATEST GUIDANCE HAS
PULLED BACK CONSIDERABLY. KEPT SOME MENTION OF ISOLD STORMS OVER
THE SAN JUANS BUT DID PULL POPS BACK SOME.
INVERSIONS TONIGHT WILL BE A LITTLE STRONGER THAN THE PREVIOUS
COUPLE OF NIGHTS IN THE WAKE OF THE NORTHERN DISTURBANCES AND A MORE
STABLE AIR MASS. THEREFORE LOOK FOR LOWS TO BE A FEW DEGREES COOLER
THAN THU NIGHT`S...AND NEAR TO...OR A COUPLE DEGREES WARMER THAN
SEASONAL NORMALS.
THE RIDGE IS PROGGED TO REBOUND ON SAT. MODELS INDICATE SOME
MOISTURE WILL BE ENTRAINED IN THE SOUTHWEST FLOW AND MOVE INTO THE
AREA THROUGH THE DAY. THEREFORE EXPECT ISOLATED TO SCATTERED LATE-DAY
MOUNTAIN THUNDERSTORMS...FAVORING THE SAN JUAN MOUNTAINS. WINDS WILL
GENERALLY REMAIN ON THE LIGHT SIDE...HOWEVER A FEW AFTERNOON GUSTS
ARE LIKELY DUE TO THE CONTINUED DEEP MIXING. ALSO ANY CONVECTION
THAT DEVELOPS WILL STILL BE RELATIVELY HIGH BASED AND WILL PRODUCE
ERRATIC AND POTENTIALLY STRONG GUSTS. TEMPERATURES WILL HOVER A FEW
DEGREES ABOVE NORMAL...AND WILL BE DEPENDENT ON CLOUD COVER.
.LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY)
ISSUED AT 242 AM MDT FRI JUN 14 2013
THE NAM INDICATES THAT ENOUGH MOISTURE WILL BE IN PLACE SAT NIGHT
FOR A FEW THUNDERSTORMS POSSIBLE THROUGH THE NIGHT. THE GFS HOWEVER
SHOWS LESS MOISTURE...BUT BOTH MODELS SHOW A LITTLE QPF OVER THE
MOUNTAINS OVERNIGHT. FEEL THAT WITHOUT THE DIURNAL EFFECTS ANY
LINGERING CONVECTION WILL BE VERY SPOTTY AT BEST.
ANOTHER ROUND OF DIURNAL MOUNTAIN CONVECTION IS POSSIBLE ON SUNDAY.
THE MODEL LAYER MOISTURE SHOWS A DECREASING TREND FROM SAT TO SUN.
HOWEVER GUIDANCE POPS SEEM A LITTLE BETTER ON SUNDAY. SO WILL BUMP
POPS A LITTLE ON SUNDAY SO THEY LOOK CLOSER TO SATURDAY`S. REALLY DO
NOT EXPECT MUCH OF A DIFFERENCE BETWEEN THE TWO DAYS.
DIURNAL CONVECTION PERSISTS THROUGH TUESDAY EVENING THOUGH
COVERAGE WILL START TO WANE AS CONVECTION SHIFTS TO THE FRONT
RANGE. DURING THIS TIMEFRAME...A DEEP AREA OF LOW PRESSURE WILL BE
APPROACHING THE PACNW COAST. IT WILL KEEP MOVING EASTWARD KEEPING
SWLY FLOW OVER UTAH AND COLORADO AND EVEN THOUGH ANY WEATHER ASSOD
WITH THIS SYSTEM WILL STAY WELL TO OUR NORTH..THE PRESSURE
GRADIENT IS EXPECTED TO TIGHTEN CAUSING SOME GUSTY WINDS WEDNESDAY
AND AGAIN THURSDAY. WITH DRY CONDITIONS HAVING PERSISTED ALL
WEEK...FIRE CONCERNS WILL START TO INCREASE.
TEMPERATURES THROUGH THE PERIOD WILL RUN A FEW DEGREES ABOVE
NORMAL BUT NOTHING EXCESSIVE.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 242 AM MDT FRI JUN 14 2013
PLENTY OF SUN AND RELATIVELY LIGHT WINDS WILL CREATE OPTIMUM
FLYING CONDITIONS TODAY. VFR CONTINUES WITH SOME BUILD UPS
EXPECTED OVER THE SAN JUANS WITH MAYBE A RUMBLE OF THUNDER OR TWO.
&&
.FIRE WEATHER...
ISSUED AT 242 AM MDT FRI JUN 14 2013
WINDS TODAY APPEAR TO FALL BELOW CRITICAL THRESHOLDS BUT MAY SEE
LOCAL GUSTS TO 25 MPH....MAINLY OVER THE NORTH.
AT THIS TIME...WINDS THROUGH THIS WEEKEND DO NOT APPEAR TO BE
HIGH ENOUGH FOR CRITICAL CONCERNS BUT WILL KEEP AN EYE ON CHANGING
CONDITIONS. A FEW HIGH BASED THUNDERSTORMS ARE POSSIBLE OVER THE
HIGHER TERRAIN EACH AFTERNOON. ERRATIC AND GUSTY WINDS ARE POSSIBLE
FROM ANY STORMS THAT DO DEVELOP. ALSO...LITTLE RAINFALL IS EXPECTED.
DRY WARM SW FLOW REMAINS IN PLACE INTO NEXT WEEK.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...NONE.
UT...NONE.
&&
$$
SHORT TERM...TGR/ELH
LONG TERM... TGR/ELH
AVIATION...TGR
FIRE WEATHER...ELH