Flash Flood Warning 9, NWS Sacramento, CA

000 
WGUS76 KSTO 042155
FFSSTO

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE SACRAMENTO CA
255 PM PDT TUE APR 4 2006

CAC005-009-099-050030-
STANISLAUS CA-AMADOR CA-CALAVERAS CA-
255 PM PDT TUE APR 4 2006

...A FLASH FLOOD WARNING CONTINUES UNTIL 530 PM PDT FOR SOUTHWESTERN
CALAVERAS...WESTERN AMADOR AND NORTHEASTERN STANISLAUS COUNTIES...

AT 245 PM PDT...RADAR CONTINUES TO INDICATE A SLOW MOVING LINE OF 
HEAVY SHOWERS AND THUNDERSTORMS EXTENDING SOUTHWARD FROM WESTERN 
AMADOR COUNTY INTO THE SAN ANDREAS AREA.

WHILE INDIVIDUAL SHOWERS AND THUNDERSTORMS CONTINUE TO REDEVELOP AND 
MOVE TO THE NORTH AT 35 MPH...THE LINE IS ONLY MOVING TO THE EAST AT 
ABOUT 10 MPH. THEREFORE...HEAVY RAIN IS REPEATED MOVING OVER THE 
SAME AREA. RADAR ESTIMATES THAT 2 TO 3 INCHES OF RAIN HAS FALLEN 
SINCE 1130 AM OVER A LARGE AREA OF WESTERN CALAVERAS AND 
NORTHEASTERN STANISLAUS COUNTIES.

THE CHP AND LOCAL LAW ENFORCEMENT OFFICIALS REPORTED NUMEROUS ROAD 
CLOSURES DUE TO FLOODING AND ROCK AND MUDSLIDES IN THE WARNING AREA. 
FLOODING OF HOMES AND ONGOING EVACUATIONS HAVE BEEN REPORTED AROUND 
THE SAN ANDREAS AREA.

DO NOT DRIVE YOUR VEHICLE INTO AREAS WHERE THE WATER COVERS THE 
ROADWAY. THE WATER DEPTH MAY BE TOO GREAT TO ALLOW YOUR CAR TO CROSS 
SAFELY. VEHICLES CAUGHT IN RISING WATER SHOULD BE ABANDONED QUICKLY. 
MOVE TO HIGHER GROUND.

DO NOT UNDERESTIMATE THE POWER OF FLOOD WATERS. ONLY A FEW INCHES OF 
RAPIDLY FLOWING WATER CAN QUICKLY CARRY AWAY YOUR VEHICLE. TURN 
AROUND...DON/T DROWN

LAT...LON 3846 12095 3747 12079 3758 12052 3783 12062
      3849 12065

$$

000 
WGUS76 KSTO 050020
FFSSTO

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE SACRAMENTO CA
520 PM PDT TUE APR 4 2006

CAC005-009-099-050100-
STANISLAUS CA-AMADOR CA-CALAVERAS CA-
520 PM PDT TUE APR 4 2006

...THE FLASH FLOOD WARNING FOR SOUTHWESTERN CALAVERAS...WESTERN 
AMADOR AND NORTHEASTERN STANISLAUS COUNTIES WILL BE ALLOWED TO 
EXPIRE AT 530 PM...

MODERATE TO OCCASIONALLY HEAVY RAIN WILL CONTINUE ACROSS THE 
MOTHERLODE AND EASTERN PORTION OF THE NORTHERN SAN JOAQUIN VALLEY 
TONIGHT AS A SLOW MOVING WEATHER SYSTEM CONTINUES TO AFFECT THE 
REGION. RADAR INDICATES THAT RAINFALL RATES HAVE LOWERED THE PAST 
COUPLE OF HOURS TO AROUND 1/4 TO 1/2 INCH AN HOUR ACROSS THE 
MOTHERLODE.

ANOTHER ONE TO THREE INCHES OF RAIN CAN BE EXPECTED OVERNIGHT WHICH 
WILL LEAD TO ADDITIONAL RUNOFF KEEPING SMALL RIVERS AND STREAMS NEAR 
OR ABOVE BANKFUL...THEREFORE THE SMALL RIVER AND STREAM FLOOD 
WARNING WILL CONTINUE IN EFFECT THIS EVENING.

LAT...LON 3846 12095 3747 12079 3758 12052 3783 12062 3849 12065

$$

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SACRAMENTO CA
930 AM PDT TUE APR 4 2006

.DISCUSSION...
AN ACTIVE DAY TODAY WITH A HEALTHY DOSE OF WINTER...FLOOD...AND
CONVECTIVE WEATHER TO BE DEALT WITH.  THE EASIEST...WINTER
WX...CONSISTS OF ONGOING HEAVY SNOWFALL IN THE HIGHER ELEVATIONS OF
THE SIERNEV RANGE WITH SNOW LEVELS FINALLY BEGINNING TO DROP.  AT
4500 TO 5000 FEET THIS MORNING NORTH OF I-80 AND NEAR 6000 FEET
NORTH OF YOSEMITE...THE LEVELS SHOULD DROP TO THE 3500 TO 4000 FOOT
RANGE BY WEDNESDAY MORNING.  WITH HEAVY PRECIP STILL FALLING IN
WAVES ACRS THE AREA UP TO ANOTHER HALF FOOT ABOVE 5000 FEET AND
POSSIBLY ANOTHER FOOT AT THE HIER ELEVATIONS IS POSSIBLE BY
WEDNESDAY MORNING.

WHICH LEADS US TO THE ISSUE OF HEAVY PRECIP/FLOODING.  A COUPLE
INCHES OF PRECIP...ON AVERAGE...HAS FALLEN ACRS INTERIOR NORCAL IN
THE PAST TWO DAYS OVER SOILS ALREADY WET FROM OUR MOIST MARCH.
RIVERS AND LARGER STREAMS COULD POSSIBLY HAVE HANDLED THE EXCESS IF
THE SNOW LEVELS WERE NOT AS HIGH AS THEY WERE...BUT THE HIGH SNOW
LEVELS RESULTED IN INCREASED RUNOFF INTO RESERVOIRS AND THEREFORE
INCREASED RELEASES NEEDED.  SO...FLOOD WARNINGS OUT ON THE MAINSTEM
SACRAMENTO AND SJ RIVERS AND SMALL RIVER AND STREAM FLOOD WARNINGS
OUT FOR THE EASTERN CENTRAL VALLEY AND ADJOINING FOOTHILLS.  WOULD
EXPECT THESE TO CONTINUE/BE EXTENDED INTO WEDNESDAY AT THE LEAST.

FINALLY...THE CONVECTIVE WX.  GUD CHC OF TSTMS ACRS INTERIOR NORCAL
LATE THIS MORNING AND WELL INTO THE AFTERNOON HOURS.  BEST CHC IS
FOCUSED IN THE SRN SAC...DELTA...AND NRN SJ VLY REGION AND INTO THE
MOTHERLODE.  DEPENDING UPON HOW THE LOW CENTER MOVES...WIND PROFILES
MAY SET UP SUCH THAT WE ARE SUSCEPTIBLE TO ROTATING UPDRAFTS AND
FUNNEL CLOUD SIGHTINGS WOULD BE EXPECTED.  BUT THAT PATTERN IS NOT
YET IN PLACE.  THE COLDER AIR ALOFT PUSHING IN IS INCREASING THE
TEMP GRAD AND IF IT STEEPENS MORE WE COULD BE IN ANOTHER ENVIRONMENT
FOR OODLES OF SMALL HAIL EVENTS.  IN GENERAL...WE ARE LUKG AT HEAVY
RAIN WITH ANYTHING THAT FORMS BUT ONLY MODERATELY STRONG WIND FLOW
OR DOWN DRAFTS.

BEYOND TODAY...THE PRECIP TAPERS OVERNIGHT TONIGHT AND OTHER THAN
CONTINUED HIGH FLOWS DUE TO RUNOFF WEDNESDAY SHUD BE A QUIETER DAY.
THURSDAY IS THE REAL BREAK IN THE ACTION AND A POSSIBLE CHC TO GET
THE LAWN MOWED FINALLY.  FRIDAY BRINGS THE NEXT SYSTEM INTO THE
REGION AND THE WEEKEND AND INTO NEXT WEEK CONTINUES THE OVERALL WET
PATTERN.

&&

.AVIATION...
PRIMARILY MVFR WX TODAY ACRS THE CNTRL VLY REGION WITH BANDS OF IFR
AS ENHANCED CELLS MOVE SW-NE THROUGH THE AREA.  ISOLD TSRA THROUGH
02Z IN MOST AREAS THOUGH BECMG SCT ACRS THE SRN SAC...DELTA...AND
NRN SJ VLYS BY AFTN.  IN/ACRS THE MTNS...SIERNEV ESPECIALLY S OF
I-80 AREAS 1/4SM RA FG AND SN ABV 050 AND MTNS OBSC...CSTL MTNS MVFR
WITH -RA BR AND LCL -TSRA.
&&

.STO WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING IN EFFECT UNTIL 5 AM PDT WEDNESDAY FOR THE WEST
SLOPES OF THE NORTHERN SIERRA NEVADA.

SMALL RIVER AND STREAM FLOOD WARNING CONTINUES UNTIL 500 PM TUESDAY
FOR STANISLAUS...WESTERN PLACER...WESTERN EL DORADO...SACRAMENTO...
AMADOR...CALAVERAS...WESTERN TUOLUMNE AND SAN JOAQUIN COUNTIES.

&&

HAZARDOUS WEATHER OUTLOOK...UPDATED
NATIONAL WEATHER SERVICE SACRAMENTO CA
1240 PM PDT TUE APR 4 2006

CAZ013>019-063-064-066>069-051400-
SHASTA LAKE AREA/NORTHERN SHASTA COUNTY-
BURNEY BASIN/EASTERN SHASTA COUNTY-NORTHERN SACRAMENTO VALLEY-
CENTRAL SACRAMENTO VALLEY-SOUTHERN SACRAMENTO VALLEY-
CARQUINEZ STRAIT AND DELTA-NORTHERN SAN JOAQUIN VALLEY-
MOUNTAINS SOUTHWESTERN SHASTA TO NORTHERN LAKE COUNTIES-
CLEAR LAKE/SOUTHERN LAKE COUNTY-MOTHERLODE-
EAST FOOTHILLS/NORTH SACRAMENTO VALLEY-
WESTERN PLUMAS COUNTY/LASSEN PARK-WEST SLOPE NORTHERN SIERRA
NEVADA-1240 PM PDT TUE APR 4 2006

...UPDATED TO ADD SEVERE THUNDERSTORM WATCH AND FLASH FLOOD
WARNING...

THIS HAZARDOUS WEATHER OUTLOOK IS FOR INTERIOR NORTHERN CALIFORNIA.

.DAY ONE...TODAY
CONTINUING MODERATE TO HEAVY RAIN AND SNOW CONTINUES TO FALL ACROSS
INTERIOR NORTHERN CALIFORNIA WITH RELATIVELY HIGH SNOW LEVELS.
REFER TO THE WINTER STORM AND FLOOD PRODUCTS FOR MORE INFORMATION.

IN ADDITION...SCATTERED THUNDERSTORMS ARE EXPECTED WITH SOME
POSSIBLY BECOMING SEVERE.  THIS HAS RESULTED IN A SEVERE
THUNDERSTORM WATCH FOR THE CENTRAL SACRAMENTO VALLEY AND SOUTHWARD.

ALSO...A LEVEE BREAK ON THE COSUMNES RIVER IS FLOODING AN
UNINHABITED AREA IN SOUTHERN SACRAMENTO COUNTY.  REFER TO THE FLASH
FLOOD WARNING FOR MORE INFORMATION.

* SEVERE THUNDERSTORM WATCH..SEE WWUS66 KSTO - WCNSTO FOR DETAILS *

* FLASH FLOOD WARNING........SEE WGUS56 KSTO - FFWSTO FOR DETAILS *

* FLOOD WARNING..............SEE WGUS46 KSTO - FLWSTO FOR DETAILS *

* RIVER FLOOD WARNING........SEE WGUS46 KSTO - FLWSTO FOR DETAILS *

* WINTER STORM WARNING.......SEE WWUS46 KSTO - WSWSTO FOR DETAILS *

.DAYS TWO THROUGH SEVEN... WEDNESDAY THROUGH MONDAY

THE SHOWERS SHOULD TAPER OFF TOMORROW BUT MAIN STEM RIVERS ARE STILL
EXPECTED TO BE HIGH. THURSDAY SHOULD BE A BRIEF DRY BREAK BEFORE
ANOTHER SYSTEM BRINGS MORE PRECIPITATION THURSDAY NIGHT THROUGH
MONDAY.

* RIVER FLOOD WARNING........SEE WGUS46 KSTO - FLWSTO FOR DETAILS *

.SPOTTER INFORMATION STATEMENT...

WEATHER SPOTTERS ARE ENCOURAGED TO REPORT SIGNIFICANT WEATHER
CONDITIONS TO THEIR LOCAL NATIONAL WEATHER SERVICE OFFICE.

THE LATEST WEATHER INFORMATION IS AVAILABLE ON THE INTERNET AT
(LOWER CASE): HTTP://WWW.WRH.NOAA.GOV/STO

HS/KJ