Heavy Snow in Utah, February 19 to 20, 2002

UTAH AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
230 PM MST TUE FEB 19 2002

.SYNOPSIS...A MOIST WESTERLY FLOW WILL PERSIST OVER THE NORTHERN
HALF OF THE AREA INTO THURSDAY WITH SOMEWHAT DRIER AIR OVER THE
SOUTH.  HIGH PRESSURE ALOFT WILL PUSH INTO THE AREA FOR FRIDAY AND
SATURDAY.

.DISCUSSION...MOIST WESTERLY FLOW INDICATED BY ALL MODELS FOR THE
NORTHERN HALF OF OUR AREA TONIGHT AND EARLY WEDNESDAY THEN A WEAKER
SECONDARY SURGE OF MOISTURE THURSDAY.  AIRMASS STAYS QUITE STABLE
MOST OF TONIGHT BUT A STRONG WESTERLY FLOW WILL PROVIDE OROGRAPHIC
LIFT IN SPITE OF THAT.  THE TAIL END OF THE SHORTWAVE MOVING THROUGH
THE CANADIAN ROCKIES BRUSHES BY LATE TONIGHT AND BRINGS A LITTLE LOW
LEVEL COLD ADVECTION AND TURNS THE FLOW A LITTLE TOWARD THE
NORTHWEST.  ALL OF THIS SUGGESTS A MID RANGE SNOW EVEN ON THE WEST
SLOPES OF THE NORTHERN MOUNTAINS ALONG WITH WINDY CONDITIONS OVER
THE RIDGES.  WILL ISSUE A SNOW AND BLOWING SNOW ADVISORY FOR ALL OF
THE NORTHERN MOUNTAIN ZONES EXCEPT THE TAVAPUTS/WASATCH PLATEAU AREA
FOR TONIGHT AND EARLY WEDNESDAY.  WASATCH FRONT VALLEYS FROM SLC
NORTHWARD SHOULD ALSO GET SOME PRECIPITATION WITH THE SLC AREA BEING
MAINLY EARLY TOMORROW.  TEMPERATURES ALSO SUCH THAT A RAIN/SNOW MIX
FOR THE VALLEYS/BENCHES RESPECTIVELY IS THE MOST LIKELY FOR THE SALT
LAKE VALLEY.  THE MOISTURE FIELD DROPS OFF MOVING TOWARD THE SOUTH.
THERE COULD BE SOME SNOW IN THE MOUNTAINS AND ALONG THE I-15
CORRIDOR NORTH OF I-70 BUT IT DOES LOOK LIKE A CHANCE SITUATION
RATHER THAN LIKELY.  SOUTH OF THAT AND IN THE EASTERN VALLEY LITTLE
IF ANY PRECIPITATION EXPECTED.

THE SECOND SURGE THURSDAY IS MOSTLY FARTHER NORTH AS HEIGHTS BEGIN
TO RISE RAPIDLY WITH THE RIDGE DEVELOPING/PUSHING INLAND.  SO SOME
CLOUDINESS OVER THE NORTH BUT NOT MUCH PRECIPITATION EXPECTED.  WILL
PROBABLY KEEP A LOW CHANCE IN THE NORTHERN WASATCH AND ID MOUNTAINS
BUT ANY AMOUNTS WOULD BE LIGHT.

FRIDAY AND SATURDAY SHOULD SEE A FAIRLY STRONG BUT SOMEWHAT FLAT
RIDGE OVER THE AREA.  THE ONLY WEATHER CONCERN MIGHT BE SOME HIGH
CLOUDINESS MOVING THROUGH THE RIDGE.  BUT OTHERWISE IT SHOULD BE
QUITE SPRING LIKE.  TEMPERATURES EVEN IN MOST OF THE NORTHERN
VALLEYS SHOULD CLIMB ABOVE NORMAL...ESPECIALLY SATURDAY AS SOME
SOUTH WINDS SHOULD DEVELOP TO HELP MIX THE WARMER AIR DOWN.

STILL MAJOR QUESTIONS ABOUT THE TIMING/STRENGTH OF THE WEEKEND
STORM.  BEST GUESS RIGHT NOW IS THAT THE 12Z AVN AND YESTERDAYS
ECMWF PROBABLY HAVE ABOUT THE BEST HANDLE ON IT.  THAT WOULD SUGGEST
THE THREAT WOULD BE SATURDAY NIGHT INTO SUNDAY MORNING AND BE MAINLY
OVER THE NORTHERN HALF OF THE AREA.  VALLEYS COULD GET SOME RAIN
AGAIN BEFORE CHANGING TO SNOW AND RIGHT NOW IT DOESNT LOOK LIKE A
MAJOR STORM.

AFTER THAT THE MRF BROUGHT A STRONG ARCTIC SURGE SOUTH INTO THE AREA
FROM WESTERN CANADA.  THE EXTENSION OF THE NEW AVN WOULD SUGGEST
THAT THE REAL COLD PUSH WILL SLIDE DOWN THE OTHER SIDE OF THE
CONTINENTAL DIVIDE.  SO EXPECT WE WILL END UP UNDER A NORTHWEST FLOW
BUT WITH JUST COOL NOT ARCTIC TEMPERATURES.  SO WILL KEEP SOME
CLOUDS IN THE NORTH WITH SLIGHTLY BELOW NORMAL TEMPERATURES WHILE
THE SOUTH SHOULD BE MOSTLY CLEAR WITH ABOVE NORMAL HIGHS.

SLC 4611 CDC 22-0  SANDERS

.SLC...SNOW/BLOWING SNOW ADVISORY NORTHERN MOUNTAINS TONIGHT AND
       EARLY WEDNESDAY...IDZ025-UTZ007>009.

UTZ002-UTZ003-UTZ004-UTZ006-UTZ007-UTZ008-201300-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE FORECAST OFFICE
SALT LAKE CITY UTAH

HAZARDOUS WINTER WEATHER POTENTIAL FOR NORTHERN UTAH
406 PM MST TUE FEB 19 2002

OVERVIEW:
MOIST WESTERLY FLOW WITH A WEAK EMBEDDED DISTURBANCE WILL BRING
SNOW TO THE NORTHERN MOUNTAINS OF UTAH OVERNIGHT. THIS WILL
BRING LIGHT SNOW, POSSIBLY MIXED WITH RAIN, TO THE VALLEYS ALONG
THE WASATCH FRONT OVERNIGHT. SNOW WILL BE HEAVIER ALONG THE
WESTERN SLOPES OF THE WASATCH MOUNTAINS, WHERE 5 TO 10 INCHES
ARE EXPECTED AND A SNOW AND BLOWING SNOW ADVISORY IS IN EFFECT.
THE MOUNTAIN VALLEYS EAST OF THE WASATCH FRONT SHOULD RECEIVE
LESS SNOW, PROBABLY 2 INCHES OR LESS. CONDITIONS IMPROVE
WEDNESDAY AFTERNOON, BUT CONTINUED MOIST NORTHWEST FLOW MAY KEEP
LIGHT SNOW ALONG THE WEST SLOPES OF THE MOUNTAINS INTO EARLY
THURSDAY.

...OGDEN CANYON/WEBER CANYON/TRAPPERS LOOP...

TONIGHT (6PM-6AM)

WEATHER:
CLOUDY WITH SNOW LIKELY. SNOW ACCUMULATION AROUND AN INCH NEAR
THE MOUTH OF THE CANYONS, BUT UP TO 4 INCHES ON TRAPPERS
LOOP.

TEMPERATURES (F):                OVERNIGHT MINIMUM
WEBER CANYON PARK AND RIDE               31
MOUNTAIN GREEN PARK AND RIDE             25

WIND:
SOUTH WINDS 5-15 MPH THIS EVEING, BECOMING WEST WINDS 5-15 MPH
TOWARD MORNING, WITH GUSTS TO 20 MPH ALONG TRAPPERS LOOP.

COMMENTS:
NONE

WEDNESDAY (6AM-6PM)

WEATHER:
CLOUDY WITH SNOW SHOWERS DECREASING. SNOW MIXED WITH RAIN NEAR
THE MOUTH OF THE CANYONS IN THE MORNING. LITTLE ADDITIONAL SNOW
ACCUMUATION NEAR THE MOUTH OF THE CANYONS, WITH AN ADDITIONAL
INCH POSSIBLE ON TRAPPERS LOOP.

TEMPERATURES (F):              8AM         NOON        4PM
WEBER CANYON PARK AND RIDE      31           38         42
MOUNTAIN GREEN PARK AND RIDE    25           29         30

WIND:
WEST WINDS 10-20 MPH IN THE MORNING, DECREASING TO 5-15 MPH BY
AFTERNOON.

COMMENTS:
NONE

...I-80/MOUTH OF PARLEYS CANYON/PARLEYS SUMMIT/KIMBALL JUNCTION...

TONIGHT (6PM-6AM)

WEATHER:
CLOUDY WITH SNOW LIKELY. SNOW ACCUMULATION AN INCH OR LESS NEAR
THE MOUTH OF PARLEYS CANYON, BUT UP TO 3 INCHES NEAR PARLEYS
SUMMIT, AND AROUND 2 INCHES NEAR KIMBALL JUNCTION.

TEMPERATURES (F):                OVERNIGHT MINIMUM
MOUTH OF PARLEYS CANYON                  32
PARLEYS SUMMIT                           26
KIMBALL JUNCTION                         27

WIND:
WEST WINDS 5-15 MPH, WITH GUSTS TO 20 MPH NEAR PARLEYS SUMMIT
NEAR MORNING.

COMMENTS:
NONE

WEDNESDAY (6AM-6PM)

WEATHER:
CLOUDY WITH SNOW SHOWERS DECREASING DURING THE AFTERNOON. SNOW
MIXED WITH RAIN NEAR THE MOUTH OF PARLEYS CANYON. ADDITIONAL
SNOW ACCUMULATION OF UP TO 2 INCHES NEAR PARLEYS SUMMIT, AND AN
ADDITIONAL INCH OR LESS NEAR KIMBALL JUNCTION.

TEMPERATURES (F):              8AM         NOON        4PM
MOUTH OF PARLEYS CANYON         32           36         37
PARLEYS SUMMIT                  26           28         31
KIMBALL JUNCTION                27           29         32

WIND:
WEST WINDS 10-20 MPH IN THE MORNING, DECREASING TO 5-15 MPH BY
AFTERNOON

COMMENTS:
NONE

...PROVO CANYON TO HEBER...

TONIGHT (6PM-6AM)

WEATHER:
CLOUDY WITH SNOW LIKELY NEAR MORNING. SNOW ACCUMULATION LESS
THAN AN INCH NEAR THE MOUTH OF PROVO CANYON, BUT 1-2 POSSIBLE
INCHES NEAR HEBER.

TEMPERATURES (F):               OVERNIGHT MINIMUM
MOUTH OF PROVO CANYON                    33
HEBER                                    26

WIND:
SOUTHWEST WINDS 5-15 MPH.

COMMENTS:
NONE

WEDNESDAY (6AM-6PM)

WEATHER:
CLOUDY WITH SNOW SHOWERS, DECREASING BY LATE AFTERNOON. SNOW
SHOWERS MIXED WITH RAIN NEAR THE MOUTH OF PROVO CANYON.
ADDITIONAL SNOW ACCUMULATION AN INCH OR LESS.

TEMPERATURES (F):              8AM         NOON        4PM
MOUTH OF PROVO CANYON           33           37         41
HEBER                           26           30         32

WIND:
NORTHWEST WINDS 10-20 MPH IN THE MORNING, DECREASING DURING THE
AFTERNOON.

COMMENTS:
NONE

...SALT LAKE VALLEY...

TONIGHT (6PM-6AM)

WEATHER:
CLOUDY WITH A CHANCE OF SNOW SHOWERS TOWARD MORNING.

TEMPERATURES (F):                OVERNIGHT MINIMUM
DOWNTOWN SALT LAKE CITY                  34
UNIVERSITY OF UTAH                       33

WIND:
SOUTH WINDS 10-20 MPH.

COMMENTS:
NONE

WEDNESDAY (6AM-6PM)

WEATHER:
CLOUDY WITH LIGHT SNOW SHOWERS LIKELY IN THE MORNING. SNOW
SHOWERS MIXING WITH RAIN AND DECREASING DURING THE AFTERNOON.
LITTLE OR NO SNOW ACCUMULATION EXPECTED.

TEMPERATURES (F):              8AM         NOON        4PM
DOWNTOWN SALT LAKE CITY         34           37         42
UNIVERSITY OF UTAH              33           38         42

WIND:
NORTHWEST WINDS 5-15 MPH.

COMMENTS:
NONE

...OGDEN/I-15 IN DAVIS-WEBER COUNTIES...

TONIGHT (6PM-6AM)

WEATHER:
CLOUDY WITH SCATTERED SNOW SHOWERS. LITTLE SNOW ACCUMULATION
ALONG I-15, BUT UP TO AN INCH ALONG THE BENCHES.

TEMPERATURES (F):                OVERNIGHT MINIMUM
DOWNTOWN OGDEN                           32

WIND:
SOUTH WINDS 5-10 MPH.

COMMENTS:
NONE

WEDNESDAY (6AM-6PM)

WEATHER:
CLOUDY WITH A FEW SNOW SHOWERS IN THE MORNING. LITTLE ADDITIONAL
SNOW ACCUMULATION EXPECTED. BECOMING MOSTLY CLOUDY IN THE
AFTERNOON.

TEMPERATURES (F):              8AM         NOON        4PM
DOWNTOWN OGDEN                  32           38         42

WIND:
WEST WINDS 5-10 MPH.

COMMENTS:
NONE

...UTAH COUNTY...

TONIGHT (6PM-6AM)

WEATHER:
CLOUDY WITH A CHANCE OF RAIN OR SNOW SHOWERS TOWARD MORNING.

TEMPERATURES (F):                OVERNIGHT MINIMUM
DOWNTOWN PROVO                           33

WIND:
SOUTH WINDS 10-15 MPH.

COMMENTS:
NONE

WEDNESDAY (6AM-6PM)

WEATHER:
CLOUDY WITH A FEW RAIN SHOWERS, POSSIBLY MIXED WITH SNOW ALONG
THE BENCHES. NO SNOW ACCUMULATION EXPECTED.

TEMPERATURES (F):              8AM         NOON        4PM
DOWNTOWN PROVO                  33           38         42

WIND:
NORTHWEST WINDS 10-15 MPH.

COMMENTS:
NONE