Avalanche in Colorado, March 18, 2006

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND JUNCTION CO
933 AM MST SAT MAR 18 2006

.UPDATE...
DECIDED TO ADD MENTION OF ISOLATED THUNDERSTORMS TO EC AND SE UT AND
SW CO THIS AFTERNOON. LIFTED INDEX DROPS BELOW ZERO WITH SOME
CAPE. SHORTWAVE ENERGY ROTATING INTO UTAH THIS AFTN ALONG WITH SOME
SURFACE HEATING FROM BREAKS IN THE CLOUDS THIS MORNING SHOULD
SHOULD BE ENOUGH TO TAP THIS INSTABILITY. IN SW CO...VORT ENERGY
LOOK LESS...BUT 700 WARM ADVECTION AND SW OROGRAPHIC FLOW MAY ALSO
PROVIDE ENOUGH LIFT TO GENERATE AN ISOLATED TSTM IN THE UNSTABLE AND
DIFFLUENT FLOW.

&&

.SHORT TERM (TODAY THROUGH SUNDAY NIGHT)...
MAINLINE MODELS DID WELL INITIALIZING THE LOW PRESSURE OVER THE
SW US. THE SOUTHERN STREAM IS EVIDENT ON SATELLITE OVER SRN NM.
IT DOESN/T APPEAR TO GET DRAWN NORTH AS THE LOW MOVES FURTHER
INLAND. THUS THIS LOW WONT BE ALL THAT WET. CLOUDS AHEAD OF THE
SYSTEM ARE SPOTTY AND THE CLOUD BAND IN THE NW QUADRANT OF THE
SYSTEM IS RATHER THIN. ERN UT AND WRN CO APPEAR TO REMAIN UNDER
THE DRIER...LESS CLOUD PART OF THE STORM FOR THE NEXT 36 HOURS OR
SO. HAVE DECIDED TO GO A BIT CONSERVATIVE WITH THE HIGHLIGHTS AND
ISSUED ONLY A SNOW ADVISORY FOR CO ZONES 18 AND 19 AND UT ZONE
28.

THIS SYSTEM WILL MOVE THROUGH THE AREA AS A BROAD CLOSED LOW. A
STRONG BAND OF SW WINDS ALOFT WILL BE OVER THE AREA THIS MORNING...
BUT BY 19/00Z THE JET AND UNDERLYING BEST OROGRAPHIC WINDS WILL PUSH
WELL SE OF THE FORECAST AREA AND REMAIN THERE THROUGH SAT NGT. SO A
LARGE AREA OF ONLY MODERATE UPLIFT AND NOT VERY IMPRESSIVE MOISTURE
SHOULD PRODUCE A LOWER GRADE SNOW EVENT...MAINLY OVER THE SOUTHERN
MOUNTAINS.

.LONG TERM (MONDAY THROUGH SATURDAY)...
MEDIUM RANGE MODELS IN GENERAL AGREEMENT DURING MOST OF THE WEEK.
MAIN DIFFERENCE IS THE GFS MUCH FASTER WITH TIMING OF NEXT PACIFIC
TROUGH IN SOUTHERN BRANCH OF SPLIT FLOW THAN DGEX OR EC. AM
CONTINUING GOING WITH THE SLOWER DGEX AND EC TIMING...WHICH AS THE
PREVIOUS PACKAGE POINTED OUT WILL DELAY THE NEXT CHANCE OF
SIGNIFICANT PRECIPITATION UNTIL LATE TUESDAY AND WEDNESDAY. SLIGHT
RIDGING ON TUESDAY WILL KEEP MOST OF THE PRECIPITATION AT BAY UNTIL
IT PASSES EAST DURING THE EVENING.

BY MIDWEEK...THE FLOW WILL BECOME MUCH MORE ZONAL AND PROGRESSIVE....
BRINGING THE WEDNESDAY SYSTEM THROUGH FAIRLY QUICKLY. ABUNDANT
MOISTURE AND DYNAMICS LOOK TO BE ASSOCIATED...BUT SPEED MAY
PRECLUDE VERY HEAVY MOUNTAIN SNOW AMOUNTS. DRYING WILL RETURN TO THE
VALLEY LOCATIONS AS AN ENHANCED RIDGE MOVES INTO THE AREA. THIS
RIDGE IS FORECAST TO AMPLIFY AS A DEEP LOW PRESSURE SYSTEM MOVES
TOWARD THE PACIFIC NORTHWEST.

OVERALL...UNSETTLED WEATHER WILL DOMINATE THE UPCOMING WORK WEEK.
DUE TO CLOUD COVER...HAVE KEPT DAYTIME HIGHS BELOW MODEL GUIDANCE.

&&

.GJT WATCHES/WARNINGS/ADVISORIES...
.CO...SNOW ADVISORY NOON TODAY THROUGH 6 PM MST SUNDAY FOR THE
      WESTERN SAN JUAN MOUNTAINS ZONES 18 AND 19.
.UT...SNOW ADVISORY NOON TODAY THROUGH 6 PM MST SUNDAY FOR THE
      ABAJO AND LA SAL MOUNTINS ZONE 28.

&&

CJC/BA/JAD

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE GRAND JUNCTION CO
453 AM MST SAT MAR 18 2006

COZ001>014-017-020>023-UTZ022>025-027-029-191230-
ANIMAS RIVER BASIN-ARCHES/GRAND FLAT-CANYONLANDS/NATURAL BRIDGES-
CENTRAL COLORADO RIVER BASIN-
CENTRAL GUNNISON AND UNCOMPAHGRE RIVER BASIN-
CENTRAL YAMPA RIVER BASIN-DEBEQUE TO SILT CORRIDOR-
EASTERN UINTA BASIN-EASTERN UINTA MOUNTAINS-
ELKHEAD AND PARK MOUNTAINS-FLAT TOPS-
FOUR CORNERS/UPPER DOLORES RIVER-
GORE AND ELK MOUNTAINS/CENTRAL MOUNTAINS-GRAND AND BATTLEMENT MESAS-
GRAND VALLEY-LOWER YAMPA RIVER BASIN-
PARADOX VALLEY/LOWER DOLORES RIVER-ROAN AND TAVAPUTS PLATEAUS-
SAN JUAN RIVER BASIN-SOUTHEAST UTAH-TAVAPUTS PLATEAU-
UNCOMPAHGRE PLATEAU AND DALLAS DIVIDE-UPPER GUNNISON RIVER VALLEY-
UPPER YAMPA RIVER BASIN-WEST ELK AND SAWATCH MOUNTAINS-
453 AM MST SAT MAR 18 2006

THIS HAZARDOUS WEATHER OUTLOOK IS FOR EASTERN UTAH AND WESTERN
COLORADO...EXCEPT THE SOUTHERN MOUNTAINS.

.DAY ONE...TODAY AND TONIGHT

AREAS OF RAIN IN THE VALLEYS AND LIGHT SNOW IN THE MOUNTAINS WILL
CONTINUE OVER THE AREA THROUGH TONIGHT. IN THE MOUNTAINS LIGHT SNOW
ACCUMULATIONS OF 1 TO 3 INCHES WILL CAUSE LOCALLY SNOWPACKED AND
ICY ROADS...WITH HAZARDOUS DRIVING.

.DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY

SUNDAY THROUGH MONDAY THERE WILL BE AREAS OF MOUNTAIN SNOW AND
VALLEY RAIN AND SNOW ACROSS THE AREA. HIGH MOUNTAIN PASSES WILL
BECOME ICY AND SNOWPACKED.

THERE IS A CHANCE MOUNTAIN SNOW AND VALLEY RAIN TUESDAY AND
WEDNESDAY...CAUSING LOCALLY HAZARDOUS WINTER DRIVING THROUGH THE
MOUNTAINS.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS NOT ANTICIPATED TODAY OR TONIGHT.  YOU ARE
ENCOURAGED TO PHONE IN SNOW REPORTS TO THE GRAND JUNCTION FORECAST
OFFICE...OR EMAIL US AT WXGJT@NOAA.GOV

COZ018-019-UTZ028-191230-
LA SAL AND ABAJO MOUNTAINS-NORTHWEST SAN JUAN MOUNTAINS-
SOUTHWEST SAN JUAN MOUNTAINS-
453 AM MST SAT MAR 18 2006

THIS HAZARDOUS WEATHER OUTLOOK IS FOR THE SAN JUAN MOUNTAINS OF
SOUTHWEST COLORADO AND THE LA SAL AND ABAJO MOUNTAINS OF SOUTHEAST
UTAH.

.DAY ONE...TODAY AND TONIGHT
A SNOW ADVISORY IS IN EFFECT FROM NOON TODAY THROUGH TONIGHT. A
PACIFIC STORM WILL BRING 6 TO 12 INCHES OF SNOW TO THE SOUTHWEST SAN
JUAN MOUNTAINS. ROADS IN THE AREA WILL BECOME ICY AND SNOWPACKED...
CAUSING HAZARDOUS WINTER DRIVING CONDITIONS.

.DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY

THE SNOW ADVISORY CONTINUES THROUGH SUNDAY AFTERNOON...AS SNOWFALL
SLOWLY DECREASES. HAZARDOUS DRIVING WILL CONTINUE THROUGH SUNDAY
NIGHT.

THERE IS A CHANCE MOUNTAIN SNOW TUESDAY AND WEDNESDAY...CAUSING
LOCALLY HAZARDOUS WINTER DRIVING.

CUOCO