Special Weather Statement

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE SAN DIEGO CA
144 PM PST MON DEC 27 2010

CAZ042-043-048-050-055>058-060>062-281300-
ORANGE COUNTY COASTAL AREAS-SAN DIEGO COUNTY COASTAL AREAS-
SAN BERNARDINO AND RIVERSIDE COUNTY VALLEYS-THE INLAND EMPIRE-
SAN DIEGO COUNTY VALLEYS-SAN BERNARDINO COUNTY MOUNTAINS-
RIVERSIDE COUNTY MOUNTAINS-SANTA ANA MOUNTAINS AND FOOTHILLS-
SAN DIEGO COUNTY MOUNTAINS-APPLE AND LUCERNE VALLEYS-
COACHELLA VALLEY-SAN DIEGO COUNTY DESERTS-
144 PM PST MON DEC 27 2010

...WINTER STORM TO AFFECT SOUTHWEST CALIFORNIA LATE TUESDAY NIGHT
AND WEDNESDAY FOLLOWED BY VERY COLD WEATHER...

A STRONG STORM APPROACHING FROM THE NORTHWEST WILL MOVE THROUGH LATE
TUESDAY NIGHT AND WEDNESDAY MORNING WITH SHOWERS LINGERING THROUGH
THE DAY WEDNESDAY. THIS FAST MOVING SYSTEM SHOULD TAP INTO DEEP
MOISTURE RESULTING IN A PERIOD OF MODERATE TO HEAVY PRECIPITATION
WITH THE FRONTAL PASSAGE WEDNESDAY MORNING.

THE SNOW LEVEL WILL BE NEAR 6000 FEET IN THE NORTHERN AREAS TO 6500
FEET FARTHER SOUTH...THEN LOWER RAPIDLY BEHIND THE COLD FRONT TO
ABOUT 4000 FEET. HOWEVER...MOST OF THE WIDESPREAD SIGNIFICANT
PRECIPITATION WILL BE OVER BY THE TIME THE SNOW LEVEL LOWERS TO 4000
FT.

RAINFALL TOTALS SHOULD RANGE FROM ABOUT A THIRD TO TWO THIRDS OF AN
INCH IN THE COASTAL AND VALLEYS AREAS WITH THREE QUARTERS OF AN INCH
TO ONE AND A QUARTER INCH ON THE COASTAL MOUNTAIN SLOPES. THERE WILL
GENERALLY BE MORE RAIN IN THE NORTH AND LESS TO THE SOUTH. THE HIGH
DESERTS SHOULD GET UP TO HALF AN INCH OF RAIN WITH LESS THAN A
QUARTER OF AN INCH IN THE LOWER DESERTS.

THE ADDITIONAL RAINFALL WILL CAUSE RAPID RUNOFF AND FLOODING DUE TO
NEARLY SATURATED GROUND FROM RECENT RAIN. THIS COULD RESULT IN
FLOODING OF LOW LYING AREAS. THERE COULD BE DEBRIS FLOWS IN AND
BELOW RECENTLY BURNED AREAS AS WELL AS ROCK AND MUD SLIDES ON STEEP
TERRAIN...AND FURTHER EROSION OF RAIN SOAKED HILLSIDES.

SAN BERNARDINO COUNTY MOUNTAIN RESORT LEVELS AND THE HIGHER
RIVERSIDE COUNTY MOUNTAINS SHOULD RECEIVE ABOUT 3 TO 8 INCHES OF
SNOW. HOWEVER...THERE COULD BE LOCALLY NEAR A FOOT OF SNOW ON THE
HIGHEST PEAKS. THERE COULD ALSO BE LOCALLY GREATER ACCUMULATIONS
DURING SNOW SHOWERS WEDNESDAY AFTERNOON AND EVENING. THE HIGHER SAN
DIEGO COUNTY MOUNTAINS COULD GET AN INCH OR TWO OF SNOW. COLD AIR
DAMMING ON THE NORTH SIDE OF THE SAN BERNARDINO MOUNTAINS COULD
RESULT IN SNOW FLURRIES IN THE HIGH DESERTS AS WELL.

STRONG GUSTY WEST TO NORTHWEST WINDS WILL ACCOMPANY THIS
SYSTEM...BECOMING EVEN STRONGER BEHIND THE FRONT WEDNESDAY NIGHT.
THE STRONGEST WINDS WILL BE IN THE MOUNTAINS AND HIGH DESERTS WHERE
THERE COULD BE WIND GUSTS OVER 60 MPH. THESE WINDS COULD CAUSE
BROKEN TREE LIMBS...DOWNED TREES AND DOWNED POWER LINES. NEAR ZERO
VISIBILITY WILL BE POSSIBLE AT TIMES DUE TO SNOW AND BLOWING SNOW.

DRY COLD NORTHWEST FLOW ALOFT WILL BRING TEMPERATURES ABOUT 10 TO 20
DEGREES BELOW SEASONAL AVERAGES THURSDAY AND FRIDAY. THERE WILL
LIKELY BE WIDESPREAD FROST IN THE INLAND VALLEYS THURSDAY AND FRIDAY
NIGHTS.

PEOPLE TRAVELING LATE TUESDAY AND WEDNESDAY SHOULD CLOSELY MONITOR
THE LATEST NATIONAL WEATHER SERVICE FORECASTS AND STATEMENTS AND
PLAN ACCORDINGLY. THE RAIN WILL CAUSE SLICK ROADS AND MOTORISTS
SHOULD USE EXTRA CAUTION. DO NOT DRIVE THROUGH FLOODED AREAS OR
AROUND BARRICADES. IF TRAVELING INTO THE MOUNTAINS...BE PREPARED FOR
THE POSSIBILITY OF WINTER STORM CONDITIONS WITH VERY LOW WIND CHILL
TEMPERATURES.

$$

ATKIN/PG