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
000
FXUS65 KGJT 301005
AFDGJT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND JUNCTION CO
405 AM MDT THU OCT 30 2014

.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 405 AM MDT THU OCT 30 2014

THE RIDGE AXIS OVER THE GREAT BASIN WILL SHIFT OVERHEAD DURING THE
DAY CAUSING TEMPERATURES TO RISE WELL ABOVE NORMAL THIS AFTERNOON.
WITH THE EXCEPTION OF PATCHES OF MID AND HIGH CLOUDS...SKIES WILL
BE SUNNY WITH RELATIVELY LIGHT TERRAIN DRIVEN WINDS.

NO SURPRISES IN THE FIRST PART OF THE FORECAST TONIGHT INTO
FRIDAY AS MODELS HAVE BEEN CONSISTENTLY AMPLIFYING THE RIDGE OVER
THE ROCKIES TONIGHT...THEN SHIFTING IT INTO THE HIGH PLAINS ON
FRIDAY. THIS SUBTLE SHIFT WILL BE DUE TO A RATHER
STRONG...ELONGATED TROUGH ARRIVING TO THE LEFT COAST OF THE CONUS.
THE ANTI CYCLONIC CENTER OF THE RIDGE WAS HAND ANALYZED AT 00Z
NEAR THE AZ/NM AND MEXICO BORDER. AS THE RIDGE BUILDS AND
TRANSLATES EAST THIS CIRCULATION SHIFTS TO THE LOWER RIO GRAND
VALLEY. 305K THETA SURFACE SHOW MOISTURE SURGING NORTHWARD OUT OF
THIS REGION ON THE BACK SIDE OF THE CIRCULATION. AMPLE MOISTURE
WILL BE FOCUSED IN THE WESTERN GULF DUE TO A COLD FRONT CURRENTLY
SETTLING INTO THIS REGION. THE NOSE OF THIS MOISTURE MOVES INTO
THE 4 CORNERS BY LATE FRIDAY BUT WILL ONLY BE NOTICEABLE BY AN
INCREASE IN HIGH LEVEL CLOUDINESS TOWARD SUNSET. TEMPERATURES
DURING THIS PERIOD WILL REMAIN ABOVE NORMAL.

.LONG TERM...(FRIDAY NIGHT THROUGH TUESDAY)
ISSUED AT 405 AM MDT THU OCT 30 2014

SIGNIFICANT HEIGHT FALLS TO OUR WEST WILL RESULT IN A
STRENGTHENING SOUTHERLY MID LEVEL JET. THIS IN TURN LEADS TO MORE
ROBUST MOISTURE ADVECTION OVER EASTERN UTAH AND WESTERN COLORADO
THIS WEEKEND. PWAT INCREASES TO NEAR 0.65 12Z SATURDAY...WHICH
FOR LATE OCTOBER IS AT LEAST 150 PERCENT OF NORMAL. LARGE SCALE
ASCENT IS INITIALLY LACKING WITH QG FORCING FOCUSED OVER THE
EASTERN GREAT BASIN. HOWEVER OROGRAPHICS AND MOIST UPGLIDE WILL
EVENTUALLY LEAD TO SHOWERS BREAKING OUT OVER THE SOUTHERN
MOUNTAINS AND ADJACENT FOOTHILL VALLEYS DURING THE EARLY MORNING
HOURS. THE QG FORCING LIFTS NORTHEAST OF OUR CWA BUT INCREASING
INSTABILITY IN THE AFTERNOON WILL CAUSE SHOWERS TO SPREAD
NORTHWARD...WITH THE TERRAIN STILL FAVORED. AN UPTICK IN WINDS
WILL DEFINITELY BE FELT ON SATURDAY AS THE INSTABILITY AIDS IN
MIXING DOWN THE STRONGER MID LEVEL WINDS. THIS MIXING LOOKS TO ADD
SOME DRY AIR INTO THE PICTURE AND MODELS ARE LEANING TOWARD A
DOWNTREND IN QPF DURING THE AFTERNOON IN RESPONSE. HOWEVER...
CONFIDENCE IN THIS SCENARIO WAS WAVERING WITH PWAT AS HIGH AS IT
IS. SO FOR NOW WILL STAY WITH GOING FORECAST. TEMPERATURES REMAIN
ABOVE NORMAL DURING THESE PERIODS AS WELL.

A COLD FRONT ASSOCIATED WITH THIS SYSTEM IS PROGGED TO PLOW
THROUGH THE REGION SATURDAY NIGHT INTO SUNDAY WITH THE GFS MORE
PROGRESSIVE THAN THE ECMWF. SNOW LEVELS ARE INDICATED TO FALL TO
NEAR 7500 WITH FROPA AND THE HIGHER ELEVATIONS MAY SEE SNOW
ACCUMULATIONS NEAR 6 INCHES IN SOME AREAS. BOTH MODELS GENERATE A
SPLIT IN THE FLOW EVENTUALLY CUTTING OFF A LOW OVER THE DESERT
SOUTHWEST. SHOWERS SHOULD CONTINUE OFF AND ON IN THE COL BETWEEN
THE NORTHERN FLOW AND THE SOUTHERN LOW ON MONDAY BEFORE DRYING
ARRIVES TUESDAY. QUIET WEATHER CONTINUES INTO WEDNESDAY AS A RIDGE
OF HIGH PRESSURE REDEVELOPS OVER THE WEST. EXPECT MARKEDLY COOLER
TEMPERATURES IN THE WAKE OF FROPA SUNDAY AND MONDAY WITH WARMER
TEMPERATURES AT MIDWEEK.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 405 AM MDT THU OCT 30 2014

WITH THE EXCEPTION OF A FEW MID AND HIGH CLOUDS...SKIES WILL BE
MOSTLY CLEAR OVER THE REGION DURING THE NEXT 24 HOURS AND VFR
CONDITIONS WILL CONTINUE.

&&

.GJT WATCHES/WARNINGS/ADVISORIES...

CO...NONE.
UT...NONE.

&&

$$

SHORT TERM...NL/15
LONG TERM...15/NL
AVIATION...NL



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