Heavy Snow in Utah, December 14 to 15, 2003

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
415 PM MST SUN DEC 14 2003

.SYNOPSIS...A PACIFIC STORM SYSTEM WILL MOVE THROUGH THE AREA
TONIGHT AND IMPACT THE AREA INTO MONDAY MORNING.  HIGH PRESSURE WILL
BUILD INTO THE AREA BY TUESDAY.
&&

.DISCUSSION...PACIFIC STORM SYSTEM MOVING INTO THE FORECAST AREA
THIS AFTERNOON.  STRONG SOUTH WINDS AHEAD OF THE SURFACE COLD FRONT
ARE SHIFTING ABRUPTLY TO THE NORTHWEST.  FRONT JUST WENT THROUGH SLC
AND WILL CONTINUE TO MOVE SOUTH AND EAST THROUGH THE NIGHT.  MODELS
STILL INSISTING ON GOOD OROGRAPHICS AND INSTABILITY BEHIND THE
FRONT.  SLC TIME HEIGHT OFF THE ETA HAS DEEP OMEGA THROUGH THE
NIGHT...THEN CONTINUES A SHALLOWER LAYER DUE TO OROGRAPHICS ALL THE
WAY THROUGH TOMORROW MIDDAY.  SYSTEM SHOWING DECENT TILT WITH HEIGHT
TO THE WEST SO EXPECT DYNAMICS ON TOP OF THESE OROGRAPHICS.
MOUNTAIN SNOWFALL AMOUNTS STILL ON TRACK FOR THE MOUNTAIN AREAS
CONSIDERING THESE FACTORS.  FOR THE NORTH WILL LIKELY BE A BREAK IN
THE MORE STEADY PRECIP BEHIND THIS INITIAL LIFT...THEN UPPER COLD
CORE CURRENTLY MOVING THROUGH OREGON MOVES OVER THE NORTH TO
INCREASE OUR INSTABILITY DEPTH LATER TONIGHT THROUGH ALMOST MIDDAY
MONDAY.  ALSO EXPECT ADVISORY WINDS FOR THE WEST DESERTS GIVEN
FAVORABLE GRADIENT SO HAVE CONTINUED THE WIND ADVISORY THROUGH THE
NIGHT THOSE AREAS.  STILL A CHANCE OF THE GSL TURNING ON IN A WINDOW
BETWEEN 10Z AND 14Z.  FAVORABLE LAKE-700 MB TEMP DIFFERENCE WITH AT
LEAST -14 C AIR MOVING OVER...NOT A LOT OF SHEAR AND AIRMASS STILL
DEEPLY UNSTABLE.  A NEGATIVE FACTOR IS THE PROGRESSIVE NATURE OF
THIS SYSTEM.  WILL HAVE TO MONITOR THROUGH THE EVENING FOR POSSIBLE
UPDATES AS USUAL.  PRECIPITATION WILL TAPER OFF TO SHOWERS BY LATER
MONDAY MORNING...THEN THINGS DRY FROM WEST TO EAST MONDAY AFTERNOON
IN ADVANCE OF A BUILDING RIDGE IN THE WEST THATS EXPECTED TO REMAIN
THROUGH MOST OF THE WEEK.

FOR THE SOUTH...UPPER VORT MAX TRACK ALONG THE UT/AZ BORDER ALONG
WITH GOOD OROGRAPHICS BEHIND THE FRONT ALONG THE I-15 CORRIDOR WILL
HELP PRODUCE AT LEAST LOW END WARNING AMOUNTS ZONES 15-16 TONIGHT.
FAVORABLE GRADIENT FOR STRONG NORTHWEST WINDS DIXIE SO HAVE KEPT THE
ADVISORY GOING TONIGHT THERE.

RIDGING ACROSS THE AREA MID WEEK THEN ANOTHER PACIFIC SYSTEM MOVES
THROUGH NEAR THE END OF THE WEEK IN TO SATURDAY.  RIGHT NOW GFS
LOOKS FAVORABLE FOR PRECIP AREA WIDE BUT ITS STARTING TO SPLIT THE
SYSTEM SO NOT A LOT OF PREDICTABILITY.  GFS NOT AGREEING WITH ECMWF
AND UKMET..BUT NONETHELESS HAVE INCLUDED PRECIP FOR FRIDAY-SATURDAY
FOR NOW.

&&

.SLC WATCHES/WARNINGS/ADVISORIES...
UT...MANY WINTER STORM WARNINGS...SNOW ADVISORIES AND WIND
     ADVISORIES FOR TONIGHT AND TOMORROW MORNING.  SEE
     SLCWSWSLC AND SLCNPWSLC FOR DETAILS.
ID...WINTER STORM WARNING THRU TOMORROW MORNING ZONE 25.
SNOW             ADVISORY ZONE 24 THROUGH TOMORROW MORNING.
WY...WINTER STORM WARNING THRU TOMORROW MORNING ZONE 21
&&

JACKSON

HAZARDOUS WEATHER OUTLOOK...CORRECTED
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
530 PM MST SUN DEC 14 2003

CORRECTED LAST SEGMENT TO MAKE INTERNET MAP GREEN

IDZ024-025-UTZ001>004-006>010-014>017-WYZ021-151400-
CACHE VALLEY/IDAHO PORTION-CACHE VALLEY/UTAH PORTION-
CENTRAL AND SOUTHWEST MOUNTAINS-NORTHERN WASATCH FRONT-
SALT LAKE AND TOOELE VALLEYS-SANPETE/SEVIER VALLEYS-
SOUTHERN WASATCH FRONT-SOUTHWEST UTAH-SOUTHWEST WYOMING-
WASATCH MOUNTAIN VALLEYS-WASATCH MOUNTAINS I-80 NORTH-
WASATCH MOUNTAINS SOUTH OF I-80-WASATCH MOUNTAINS/IDAHO PORTION-
WASATCH PLATEAU/BOOK CLIFFS-WEST CENTRAL UTAH-
WESTERN UINTA MOUNTAINS-
530 PM MST SUN DEC 14 2003

THIS HAZARDOUS WEATHER OUTLOOK IS FOR THE MOUNTAINS OF UTAH AND
EXTREME SOUTHEAST IDAHO...THE MOUNTAIN VALLEYS AND WESTERN VALLEYS
AND SOUTHWEST WYOMING.

.DAY ONE... TONIGHT

WINTER WEATHER PRODUCTS HAVE BEEN ISSUED FOR TONIGHT AS A STRONG
COLD FRONT MOVES THROUGH THE AREA. SEE SLCWSWSLC FOR DETAILS.

.DAYS TWO THROUGH SEVEN... MONDAY THROUGH SATURDAY

WINTER WEATHER PRODUCTS WILL BE VALID THROUGH MONDAY MORNING.
SNOWFALL WILL DECREASE DURING THE DAY.

.SPOTTER INFORMATION STATEMENT...

WEATHER SPOTTERS ARE ENCOURAGED TO REPORT SIGNIFICANT WEATHER
CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURE.

UTZ005-019-020-151400-
GREAT SALT LAKE DESERT AND MOUNTAINS-SOUTH CENTRAL UTAH-
UTAHS DIXIE AND ZION NATIONAL PARK-
530 PM MST SUN DEC 14 2003

THIS HAZARDOUS WEATHER OUTLOOK IS FOR NORTHWEST UTAH...UTAHS
DIXIE AND SOUTH CENTRAL UTAH.

.DAY ONE... TONIGHT

WINDY CONDITIONS WILL EXIST THIS EVENING. WIND ADVISORIES HAVE BEEN
ISSUED. SEE SLCNPWSLC FOR DETAILS.

.DAYS TWO THROUGH SEVEN... MONDAY THROUGH SATURDAY

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...

WEATHER SPOTTERS ARE ENCOURAGED TO REPORT SIGNIFICANT WEATHER
CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURE.

UTZ011>013-018-021-151400-
CASTLE COUNTRY-GLEN CANYON RECREATION AREA/LAKE POWELL-
HENRY MOUNTAINS-SAN RAFAEL SWELL-WESTERN UINTA BASIN-
530 PM MST SUN DEC 14 2003

THIS HAZARDOUS WEATHER OUTLOOK IS FOR MUCH OF SOUTHERN AND
EASTERN UTAH.

.DAY ONE... TONIGHT

NO HAZARDOUS WEATHER IS EXPECTED. HOWEVER...TRAVELERS LEAVING
THE AREA THROUGH SURROUNDING MOUNTAINS WILL ENCOUNTER WINTER DRIVING
CONDITIONS.

.DAYS TWO THROUGH SEVEN... MONDAY THROUGH SATURDAY

GUSTY NORTH WINDS WILL OCCUR ON MONDAY WITH SNOW SHOWERS NEAR THE
MOUNTAINS...OTHERWISE NO HAZARDOUS WEATHER IS EXPECTED.

.SPOTTER INFORMATION STATEMENT...

WEATHER SPOTTERS ARE ENCOURAGED TO REPORT SIGNIFICANT WEATHER
CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURE.