Winter Storm in Colorado, February 7 to 8, 2005

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND JUNCTION CO
508 AM MST MON FEB 7 2005

.SHORT TERM (TONIGHT THROUGH TUESDAY)...
SNOW HAS BEGUN TO FALL OVER PORTIONS OF EASTERN UTAH AND WESTERN
COLORADO THIS EARLY MORNING. THIS FIRST, WEAK, ROUND IS IN
ASSOCIATION WITH A WEAK WAVE THAT THE MESOETA POINTS OUT FAIRLY
WELL. THE REAL ONSLAUGHT OF THE PRECIPITATION WILL LIKELY TAKE PLACE
LATER THIS MORNING WITH THE MUCH STRONGER WAVE OVER THE WESTERN HALF
OF UTAH.

THE ATMOSPHERE IS STILL FAIRLY DRY OVER WESTERN COLORADO...WITH DEW
POINT SPREADS OF 7 TO 15 F AT THE SURFACE. MORE MOIST AIR CAN BE SEEN
SPREADING INTO EASTERN UTAH, HOWEVER. MESOETA SHOWS WIDESPREAD LOW
LEVEL MOISTURE OVER WESTERN COLORADO BY 15Z...WHICH SEEMS REASONABLE
ENOUGH.

SOUTHWEST-FACING SLOPES OF THE MOUNTAINS OF EASTERN UTAH AND
SOUTHWEST COLORADO STILL SEEM TO BE THE FAVORED AREAS FOR
SIGNIFICANT SNOW TODAY. HAVE ADDED ADVISORY SNOW AMOUNTS TO THE
MOUNTAINS AND PLATEAUS OF NORTHERN COLORADO. WITH LOW PRESSURE
TRACKING ACROSS THE AREA, SNOW WILL LIKELY FALL...EVEN WITHOUT A
GOOD NORTHWEST FLOW. STILL, A LACK OF REALLY GOOD JET SUPPORT AND
NOT VERY COLD AIR ALOFT WILL LIKELY PRECLUDE WIDESPREAD HEAVY SNOW
AMOUNTS IN THIS REGION.

WITH FAVORABLE MOISTURE AND DYNAMICS IN THE SOUTH, WILL ALSO ADD
ADVISORY SNOW AMOUNTS TO THE DURANGO AND PAGOSA SPRINGS AREAS.

SYSTEM REMAINS PROGRESSIVE AND WILL BE PULLING OUT OF THE AREA ON
TUESDAY. WEST FLOW SHOULD KEEP SOME SNOWS GOING ALONG THE
CONTINENTAL DIVIDE BUT SIGNIFICANT ACCUMULATING SNOWS SHOULD BE
WINDING DOWN TUESDAY MORNING. LINGERING SNOW WILL LIKELY CONTINUE IN
THE NORTHERN MOUNTAINS AND THE SAN JUANS THROUGHOUT THE DAY ON
TUESDAY, BUT THE BRUNT OF THE ENERGY SHOULD BE EAST OF THE AREA BY
THEN.  BA

.LONG TERM (WEDNESDAY THROUGH MONDAY)...
WEAK SHORT WAVE BRUSHES NWRN COLORADO WEDNESDAY AFTERNOON.  NEITHER
THE 00Z GFS OR NAM MODEL SHOWED ANY PCPN WITH THIS FEATURE...BUT
WOULD NOT BE SURPRISED IF LIGHT SNOW DID OCCUR NEAR THE ELKHEAD
MOUNTAINS AND PARK RANGE.  BUT MODELS HAVE BEEN HAVING TROUBLE
HANDLING THE SPLIT FLOW OVER THE ERN PACIFIC OCEAN AND WRN CONUS...
SO PROGGED SHORT WAVE MAY BE FARTHER EAST.  OTHERWISE NO THREAT OF
PCPN ANYWHERE ELSE IN OUR FORECAST AREA.  UNDERCUT MOS TEMPS BY A
TAD IN THE WAKE OF SHORT WAVE AND FRESH SNOW COVER FOR THE MOUNTAIN
AREAS AND HIGHER VALLEYS.

MODEL DATA HAVE BEEN CONSISTENT WITH THE IDEA OF A BROAD CLOSED LOW
CIRCULATION FORMING WEST OF BAJA CALIFORNIA AROUND MID WEEK.  NO
IMPACT ON SENSIBLE WEATHER UNTIL THURSDAY NIGHT AT THE EARLIEST...AT
THAT TIME DEEP SOUTHERLY FLOW MAY REACH SERN UTAH AND SWRN COLORADO
AND LAST INTO SATURDAY.  MODELS SHOW NICE MOISTURE FEED ASSOCIATED
WITH THE SUBTROPICAL JET...SO THE POTENTIAL EXISTS FOR DECENT SNOW
ACCUMULATION FOR THE SAN JUAN AND LA SAL/ABAJO MOUNTAINS.  THE SNOW
LEVELS WILL BE ABOVE THE VALLEY FLOORS AS THIS SYSTEM WILL BE
RELATIVELY WARM.

LOTS OF QUESTION MARKS FOR DAYS 7 AND 8 WITH THE GFS SHOWING A
CONVERGENCE OF THE NRN AND SRN BRANCH CONVERGING WEST OF THE NRN
CALIFORNIA COAST...THEN WESTERLY FLOW BRINGING ACTIVE WEATHER
SYSTEMS INLAND.  FOR RIGHT NOW...NO CHANGES WERE MADE IN THE
GRIDDED DATA THAT SHOWS LOW POPS FOR THE NRN MOUNTAINS.

&&

.GJT WATCHES/WARNINGS/ADVISORIES...
.CO...WINTER STORM WARNING UNTIL NOON TUESDAY FOR
          SOUTHWEST AND CENTRAL MOUNTAIN ZONES 9/12/17/18/19.
      WINTER WEATHER ADVISORY UNTIL 6 AM TUESDAY FOR
          ROAN/TAVAPUTS PLATEAU ZONE 3.
      WINTER WEATHER ADVISORY UNTIL NOON TUESDAY FOR
          ZONES 2/4/5/8/10/13/14/22/23.
.UT...WINTER STORM WARNING UNTIL 6 AM TUESDAY FOR
          THE LA SAL AND ABAJO MOUNTAINS ZONE 28.
      WINTER WEATHER ADVISORY UNTIL 6 AM TUESDAY FOR
          THE EAST-CENTRAL AND NORTHEAST UTAH MOUNTAIN ZONES 23/25.

&&

BA/PF

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE GRAND JUNCTION CO
600 AM MST MON FEB 7 2005

COZ001>014-017>023-UTZ022>025-027>029-081300-
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-LA SAL AND ABAJO MOUNTAINS-LOWER YAMPA RIVER BASIN-
NORTHWEST SAN JUAN MOUNTAINS-PARADOX VALLEY/LOWER DOLORES RIVER-
ROAN AND TAVAPUTS PLATEAUS-SAN JUAN RIVER BASIN-SOUTHEAST UTAH-
SOUTHWEST SAN JUAN MOUNTAINS-TAVAPUTS PLATEAU-
UNCOMPAHGRE PLATEAU AND DALLAS DIVIDE-UPPER GUNNISON RIVER VALLEY-
UPPER YAMPA RIVER BASIN-WEST ELK AND SAWATCH MOUNTAINS-
600 AM MST MON FEB 7 2005

THIS HAZARDOUS WEATHER OUTLOOK IS FOR EASTERN UTAH AND WESTERN
COLORADO...

...WINTER STORM ADVISORIES AND WARNINGS ARE IN EFFECT UNTIL 6 AM MST
TUESDAY FOR THE MOUNTAINS OF EASTERN UTAH...
...A WINTER STORM WARNING IS IN EFFECT UNTIL NOON TUESDAY FOR THE
MOUNTAINS OF WEST CENTRAL AND SOUTHWEST COLORADO...
...WINTER WEATHER ADVISORIES ARE IN EFFECT UNTIL NOON TUESDAY FOR
PORTIONS OF NORTHERN COLORADO AND THE LOWER ELEVATIONS OF EXTREME
SOUTHWEST COLORADO....

.DAY ONE...TODAY AND TONIGHT...

SNOW WILL BECOME WIDESPREAD...AND HEAVY AT TIMES...TODAY ACROSS THE
MOUNTAINS OF EASTERN UTAH AND WESTERN COLORADO. SEE THE LATEST WINTER
WEATHER PRODUCTS FOR MORE INFORMATION ON WARNINGS AND ADVISORIES.

PRECIPITATION IN THE LOWER ELEVATIONS WILL BE A MIXTURE OF RAIN
AND SNOW.  ONLY LIGHT ACCUMULATIONS OF SNOW WILL BE EXPECTED...
OR 2 INCHES OR LESS.

HAZARDOUS DRIVING CONDITIONS CAN BE EXPECTED TODAY AND
TONIGHT...MAINLY ON ROADWAYS ABOVE 6000 FEET.

.DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY...

SIGNIFICANT SNOW ACCUMULATIONS ARE EXPECTED FOR THE MOUNTAINS BY
TUESDAY AFTERNOON...RESULTING IN HAZARDOUS WINTER CONDITIONS FOR
TRAVELERS AND THOSE PLANNING OUTDOOR ACTIVITIES.  BY TUESDAY
AFTERNOON...STORM TOTAL SNOWFALL OF 1 TO 2 FEET IS POSSIBLE IN MOST
MOUNTAINS OF WESTERN COLORADO AND SOUTHEAST UTAH. 8 TO 14 INCHES OF
NEW SNOW CAN BE EXPECTED IN THE MOUNTAINS OF NORTHEAST UTAH ABOVE THE
7000 FOOT LEVEL...WITH LESSER AMOUNTS BELOW 7000 FEET.

A BREAK IN THE SNOWFALL IS EXPECTED FOR WEDNESDAY...FOLLOWED BY A
CHANCE OF SNOW IN THE MOUNTAINS BY LATE THURSDAY AND CONTINUING INTO
SATURDAY MORNING...THEN BECOMING A SLIGHT CHANCE OF SNOW OVER THE
REMAINDER OF THE WEEKEND.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION WILL NOT BE NEEDED TODAY OR TONIGHT...ALTHOUGH
WEATHER AND PRECIPITATION REPORTS TO THE NATIONAL WEATHER SERVICE IN
GRAND JUNCTION WILL BE APPRECIATED.

BA/PF