Warning Description: Special Weather Statement

Warning Date: 1:43 PM PST on February 8, 2010

WarningSum:


Warning Message:A cold low pressure system is forecast to move across Southern
California Tuesday afternoon through Wednesday. The snow level
will be lowering Tuesday night to below 3000 feet and to near 2000
feet on Wednesday. 
This means that significant amounts of snow may accumulate over
the foothills and in the higher inland valleys. 
For Tuesday night into Wednesday morning...total snowfall amounts
for elevations between 2000 feet and 3500 feet are forecast to
range between 2 and 4 inches...and may be higher along the
foothills of the San Bernardino Mountains. 
This will impact all roads passing through the mountains.
Winter storm watches are already in effect for the mountains...
and a Winter Weather Advisory may be in effect for the inland
Empire and inland valleys of San Diego County Tuesday night
through Wednesday.
There is also the possibility of thunderstorms with hail
Wednesday. Hail accumulations along the coast and over the inland
valleys could be an inch or more.
        

Expires:No;;661552
FXUS66 KSGX 082235
AFDSGX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN DIEGO CA
233 PM PST MON FEB 8 2010
.SYNOPSIS...
A DEEPENING LOW PRESSURE SYSTEM MOVING SOUTH ALONG THE WEST COAST 
TONIGHT...IS EXPECTED TO TURN EAST ON TUESDAY...MOVING ACROSS 
SOUTHERN CALIFORNIA TUESDAY NIGHT AND WEDNESDAY. WINTER STORM 
WATCHES HAVE BEEN ISSUED FOR THE MOUNTAINS DUE TO THE POSSIBILTY OF 
HEAVY SNOW. WINTER WEATHER ADVISORIES MAY BE ISSUED FOR TUESDAY 
NIGHT AND WEDNESDAY TO INCLUDE THE HIGH DESERTS...FOOTHILLS...AND 
INLAND VALLEYS. HAIL FROM THUNDERSTORMS WEDNESDAY MAY ALSO ICY 
CONDITIONS FOR AREAS CLOSE TO THE COAST. WEAK HIGH PRESSURE WILL 
REBUILD THURSDAY. A TROUGH MOVING INLAND TO THE NORTH ON FRIDAY MAY 
BRING SOME LIGHT RAIN AND SNOW. WARMING AND DRYING IS FORECAST FOR 
FOR THE WEEKEND.
&&
.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...
&&
.SHORT TERM...TONIGHT THROUGH THURSDAY...
HIGH PRESSURE RIDGE ALOFT WILL CONTINUE THROUGH THE NIGHT. A VERY 
COLD LOW IN THE VICINITY OF 45N 132W AT 1300 PST...WITH HEIGHTS OF 
5350-5400 METERS AT 500 MB...CONTINUES TO DROP SOUTH SOUTHEASTWARD 
ALONG THE WEST COAST AS FORECAST BY ALL MODELS. A TURN TOWARDS THE 
EAST AS IT GETS OVER THE SOUTHERN CALIFORNIA BIGHT AND TRACKING 
DIRECTLY ACROSS SOUTHWEST CALIFORNIA ALSO APPEARS LIKELY. 
FAIRLY HIGH CONFIDENCE IN THIS FORECAST SOLUTION AS WELL AS WINTER 
STORM CONDITIONS DEVELOPING. HAVE ISSUED THE WINTER STORM WATCH FOR 
THE MOUNTAINS AND A SPECIAL WEATHER STATEMENT FOR THE REMAINDER OF 
THE FORECAST ZONES WITH THE IDEA THAT THIS WILL BE LATER UPGRADED TO 
A WINTER WEATHER ADVISORY. THE STRONG DIVERGENCE ALOFT IS STILL 
SHOWN AND THIS RAISES THE QUESTION OF SEVERE THUNDERSTORM 
DEVELOPMENT  LATE TUESDAY NIGHT AND WEDNESDAY. FOR NOW HAVE INCLUDED 
MENTION OF THUNDERSTORMS WITH SMALL HAIL FOR MOST ZONES AND ISOLATED 
WATERSPOUTS OVER WATER. WRAP AROUND MOISTURE INTO WEDNESDAY EVENING. 
CLEARING WEDNESDAY NIGHT INTO THURSDAY MORNING AND LINGERING COLD 
AIR SHOULD ALLOW FROST FORMATION OVER LOWER DESERTS/VALLEYS. 
SIGNIFICANTLY UNDERCUT MOS TEMPS FOR WEDNESDAY NIGHT/THURSDAY 
MORNING. FOR THURSDAY WARMER AND GENERALLY CLEAR THOUGH MAY SEE 
INCREASING CIRROSTRATUS TOWARDS THE END OF THURSDAY FROM LIFTING DUE 
TO WARM AIR OVERRUNNING AHEAD OF NEXT TROUGH. 
.LONG TERM...THURSDAY NIGHT INTO SUNDAY...
BOTH THE ECMWF AND GFS HAVE TRENDED TOWARDS WASHING OUT THE NEXT 
TROUGH SOUTH OF POINT CONCEPTION FRIDAY/FRIDAY NIGHT. MODIFIED 
CLOUDS/POPS/WEATHER GRIDS SLIGHTLY TO KEEP A SLIGHT CHANCE OF LIGHT 
RAIN/SNOW FOR FRIDAY INTO FRIDAY EVENING. AFTER FRIDAY 
EVENING...HIGH PRESSURE RIDGE REBUILDS AND WEEKEND LOOKS FAIRLY 
NICE. ONLY SPOILER MIGHT BE A BACKDOOR COLD FRONT COMING ACROSS THE 
MOJAVE DESERT LATE SATURDAY/SUNDAY FROM THE CLOSED LOW THAT IS 
FORECAST TO DEVELOP AFTER THE TROUGH MOVES INLAND. CURRENTLY THIS 
SCENARIO IS NOT INCLUDED IN THE EXTENDED FORECAST TEMPS.
&&
.AVIATION...
082000Z...SCATTERED STRATOCU WITH BASES AROUND FL030 SHOULD DIMINISH 
AFTER SUNSET. A MOSTLY CLEAR SKY IS EXPECTED TONIGHT WITH SOME 
RADIATIONAL FOG DEVELOPING NEAR SUNRISE IN THE USUAL LOCATIONS SUCH 
AS KCNO...KAJO AND KRNM. EXPECT AN INCREASE IN MID AND HIGH CLOUDS 
WITH BASES AT OR ABOVE FL150 TUESDAY AFTERNOON AND LOWER STRATOCU/CU 
WITH BASES BETWEEN FL030 AND FL040 AHEAD OF THE NEXT STORM MOVING IN 
FROM THE NORTHWEST.  HORTON
&&
.HYDROLOGY...
BECAUSE OF THE EXTREMELY LOW FREEZING LEVELS...DROPPING TO 2000 
FEET...THINKING THIS WILL BE A HEAVY SNOW EVENT RATHER THAN A HEAVY 
RAIN EVENT. PRECIPITATION RATES HOWEVER COULD BE ONE INCH PER HOUR 
OR HIGHER TUESDAY NIGHT INTO WEDNESDAY MORNING JUST AHEAD OF AND 
ALONG THE COLD FRONT...AND BRIEFLY IN THUNDERSTORMS THAT DEVELOP ON 
WEDNESDAY. QPF AMOUNTS WERE ADJUSTED SLIGHTLY TO SHOW MORE UPSLOPE 
PRECIPITATION ALONG THE NORTH AND EAST SLOPES WEDNESDAY...OTHERWISE 
NUMBERS ARE ABOUT THE SAME. 
WATER EQUIVALENT QPF AMOUNTS ARE...
ORANGE COUNTY/SW SAN BERNARDINO COUNTY...0.50 TO 1.00 INCHES AT THE 
COAST TO 1.5 TO 2.5 INCHES ON THE COASTAL SLOPES...AND 0.50 TO 1.00 
INCHES HIGH DESERT AREAS....AND FOR  
WESTERN RIVERSIDE/SAN DIEGO COUNTIES...0.50 TO 0.75 INCHES AT THE 
COAST TO 1 TO 2 INCHES COASTAL SLOPES....AND 0.25 TO 0.50 INCHES 
LOWER DESERTS. 
SNOW FALL AMOUNTS...USED TEN TO ONE SNOW TO WATER RATIO THROUGH 10 PM 
TUESDAY THEN SLOWLY RAISED IT ABOUT ONE INCH EVERY SIX HOURS 
THEREAFTER. 
IN THE SAN GABRIEL MOUNTAINS...THE SAN BERNARDINO MOUNTAINS...AND 
THE SAN JACINTO MOUNTAINS...SNOWFALL AMOUNTS COASTAL SLOPES 8 TO 20 
INCHES BETWEEN 3500 AND 6500 FEET AND OVER THREE FEET AT ELEVATIONS 
ABOVE 7000 FEET. DESERT SLOPES...4 TO 8 INCHES. 
IN THE SANTA ANA MOUNTAINS...THE SANTA ROSA MOUNTAINS...AND THE 
MOUNTAINS IN SAN DIEGO COUNTY...SNOWFALL AMOUNTS COASTAL SLOPES 4 TO 
8 INCHES BETWEEN 3500 AND 5000 FEET AND 8 AND 20 INCHES AT 
ELEVATIONS ABOVE 5000 FEET. DESERT SLOPES 2 TO 6 INCHES.
FOR HIGH DESERT VALLEY FLOORS...COASTAL FOOTHILLS/INLAND 
VALLEYS...LOWER DESERTS...BETWEEN 2000 AND 3500 ELEVATION...SNOW 
AMOUNTS BETWEEN 1 AND 4 INCHES ARE FORECAST.
HAIL ACCUMULATIONS WEDNESDAY COULD ADD ANOTHER INCH OR TWO AT LOWER 
ELEVATIONS. 
&&
.SGX WATCHES/WARNINGS/ADVISORIES...
CA...WINTER STORM WATCH FROM TUESDAY AFTERNOON THROUGH WEDNESDAY 
     AFTERNOON FOR RIVERSIDE COUNTY MOUNTAINS-SAN BERNARDINO 
     COUNTY MOUNTAINS-SAN DIEGO COUNTY MOUNTAINS-SANTA ANA 
     MOUNTAINS AND FOOTHILLS.
PZ...NONE.
&&
$$
PUBLIC...BALFOUR
AVIATION/MARINE...HORTON
NWS ON THE WEB AT WEATHER.GOV/SANDIEGO

Expires:No;;663087
SXUS86 KSGX 090001
CGRSGX
COASTAL WEATHER OBSERVATIONS
NATIONAL WEATHER SERVICE SAN DIEGO CA
400 PM PST MON FEB 8 2010
ID  /WX VSB   / WIND   / WAVE / SEA/ AIR/ PRESS/ REMARKS   STATION
6L9  C10      / W07    / 0612 / 60 / 58 / 1014 /           HUNTINGTON BEACH
3L3  C20      / SW05   / 0308 / 58 / 61 /      / MX5       NEWPORT BEACH
2L7  C10      / SW07   / 0309 / 58 / 63 / 1015 / MX4       SOLANA BEACH
L58  PC08     / NW10   / 0408 / 59 / 59 / 1014 / MX5       MISSION BEACH

Expires:No;;664097
SXUS86 KLOX 090033
CGRLOX
COASTAL WEATHER OBSERVATIONS
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
400 PM PST MON FEB 08 2010
ID   WX VSB   WIND      WAVE   SEA  AIR  REMARKS    STATION NAME
1MB  PCH05  / NW15G20 / 0912 / 56 / 55 / NW/MX11    MORRO BAY
P44  PC10   / SW10    / 0110 / 57 / 64 / SW/MX2     SANTA BARBARA HBR
L79  C10    / W08     / 0410 / 57 / 61 / W SWL      CHANNEL ISLANDS HBR
L27  C10    / E01     / FLAT / 58 / 58 /            AVALON HARBOR
OL3  CH06   / W05     / 0308 / 57 / 57 / W/MX5      ZUMA BEACH
L14  C10    / SW11    / 0210 / 58 / 58 / SW/MX3     CABRILLO BEACH