Severe Thunderstorm Warning 1, NWS San Francisco Bay Area, CA

477 
WWUS56 KMTR 010302
SVSMTR

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE SAN FRANCISCO CA
802 PM PDT SUN MAR 31 2013

CAC013-010310-
/O.EXP.KMTR.SV.W.0001.000000T0000Z-130401T0300Z/
CONTRA COSTA CA-
802 PM PDT SUN MAR 31 2013

...THE SEVERE THUNDERSTORM WARNING FOR CONTRA COSTA COUNTY HAS
EXPIRED...

RADAR SHOWS THE THUNDERSTORM HAS BEEN WEAKENING. THE SEVERE 
THUNDERSTORM WARNING HAS BEEN ALLOWED TO EXPIRE. FREQUENT 
LIGHTNING...SMALL HAIL AND HEAVY DOWNPOURS ARE STILL POSSIBLE WITH 
THE THUNDERSTORM UNTIL 9 PM PDT.

LAT...LON 3810 12158 3802 12158 3802 12167 3809 12167
TIME...MOT...LOC 0300Z 210DEG 12KT 3807 12156

$$

CANEPA

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA
535 PM PDT SUN MAR 31 2013

.DISCUSSION...AS OF 1:35 PM PDT SUNDAY...SATL IMAGERY IS INDC AN
UPPER LOW WEST OF SAN FRANCISCO MOVING TOWARDS THE COAST. AS
INSTABILITY HAS INCREASED KMUX HAS BEEN SHOWING INCREASING SHOWER
ACTIVITY OVER THE DISTRICT...BUT NO LIGHTNING OVER THE DISTRICT
OR OVER THE COASTAL WATERS AT THIS TIME. INTERESTING TO NOTE THAT THE
STORM PREDICTION CENTER HAS PART OF THE DISTRICT IN A SLIGHT RISK
OF SEVERE HAIL THROUGH THE EVENING HOURS.

UPPER LOW IS FORECAST BY THE MODELS TO MOVE ACROSS THE DISTRICT
THIS EVENING. SHOWERS AND THUNDERSTORMS ARE POSSIBLE...WITH SHOWER
ACTIVITY DECREASING AFTER MIDNIGHT. MODELS DO KEEP WEAK TROUGHING
OVER THE DISTRICT ON MONDAY...AND WITH LINGERING MOISTURE THERE
COULD BE A FEW SHOWERS ON MONDAY...BUT ANY RAIN WILL BE VERY LIGHT.

RIDGING WILL BUILD ALONG THE COAST TUESDAY AND WEDNESDAY. THIS
WILL RESULT IN DRY AND MILD WEATHER THOSE DAYS. A COUPLE OF
SHORTWAVES WILL MOVE ACROSS THE DISTRICT WEDNESDAY NIGHT THROUGH
THURSDAY NIGHT BRINGING THE THREAT OF RAIN/SHOWERS BACK TO THE
DISTRICT. HAVE KEPT THE THREAT OF SHOWERS RIGHT THROUGH THE
UPCOMING WEEKEND AS A SERIES OF FAST MOVING IMPULSES MOVES ACROSS
THE DISTRICT IN A ZONAL FLOW.

&&

.AVIATION...AS OF 5:35 PM PDT SUNDAY...HAVE KEPT VCSH IN FOR 00Z
TAF PACKAGE THROUGH 06Z OVER ALL TERMINALS AS SHOWERS CONTINUE TO
ROTATE IN TOWARD THE COAST AS THE LOW SHIFTS EAST THROUGH TONIGHT.
WOULD NOT RULE OUT THE POSSIBILITY OF AN ISOLATED THUNDERSTORM
THEREFORE WILL CONTINUE TO CLOSELY WATCH FOR ANY DEVELOPMENT
THROUGH THIS EVENING. WINDS WILL CONTINUE TO BE VARIABLE WITH
PERIODIC MODERATE GUSTS ASSOCIATED WITH CONVECTIVE OUTFLOW
BOUNDARIES...I.E. THUNDERSTORMS. MODERATE CONFIDENCE.

VICINITY OF KSFO...VFR CONDITIONS EXPECTED THROUGH THIS EVENING
WITH MVFR CONDITIONS EXPECTED AFTER 10Z TONIGHT. POSSIBLE SHOWERS
THROUGH ABOUT 06Z WITH A VERY SMALL CHANCE OF AN ISOLATED
THUNDERSTORM. WINDS WILL REMAIN VARIABLE AND AT TIMES GUSTY THROUGH
THIS EVENING AS THE LOW MOVES INLAND AND SHOWERS AND POSSIBLE
ISOLATED THUNDERSTORMS MOVE ACROSS THE REGION. MODERATE
CONFIDENCE.

KSFO BRIDGE APPROACH...SIMILAR TO KSFO.

MONTEREY BAY AREA TERMINALS..VFR CONDITIONS EXPECTED THROUGH
TONIGHT. POSSIBLE SHOWERS THROUGH ABOUT 06Z WITH A VERY SMALL
CHANCE OF AN ISOLATED THUNDERSTORM. WINDS WILL REMAIN WEST TO
SOUTHWEST AND AT TIMES GUSTY THROUGH THIS EVENING. WINDS WILL
BECOME LIGHT AND OFFSHORE OVERNIGHT. MODERATE CONFIDENCE.

&&

.CLIMATE...AS OF 3:50 AM PDT SUNDAY...DOWNTOWN SAN FRANCISCO IS ON
TRACK TO HAVE ITS DRIEST JANUARY THROUGH MARCH ON RECORD. SAN
FRANCISCO HAS A CONTINUOUS RAINFALL DATA SET DATING BACK TO
1850...SO IT IS NOTABLE WHEN RECORDS ARE BROKEN THERE. BETWEEN
JANUARY 1 AND MARCH 30...ONLY 1.82 INCHES OF RAIN HAD BEEN
RECORDED IN THE CITY. THIS AMOUNT IS 1.38 INCHES BELOW THE CURRENT
DRIEST JANUARY THROUGH MARCH RECORD OF 3.20 INCHES SET ALL OF THE
WAY BACK IN 1850. THE AVERAGE RAINFALL IN SAN FRANCISCO FOR THE
3-MONTH PERIOD OF JANUARY THROUGH MARCH IS 12.22 INCHES. MORE RAIN
IS FORECAST TO FALL IN THE CITY ON SUNDAY MARCH 31ST...BUT
PROBABLY NOT ENOUGH TO BRING THE 3-MONTH TOTAL TO 3.20 INCHES.
THUS...IT'S LIKELY THIS JANUARY-MARCH WILL BE THE DRIEST ON
RECORD.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
     .TNGT...NONE.

PUBLIC FORECAST: STROBIN
AVIATION/MARINE: CW
CLIMATE: BELL/DYKEMA

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