

000 

WGUS56 KSGX 222121

FFWSGX

CAC073-222315-

/O.NEW.KSGX.FF.W.0027.080522T2115Z-080522T2315Z/

/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/



BULLETIN - EAS ACTIVATION REQUESTED

FLASH FLOOD WARNING

NATIONAL WEATHER SERVICE SAN DIEGO CA

215 PM PDT THU MAY 22 2008



THE NATIONAL WEATHER SERVICE IN SAN DIEGO HAS ISSUED A



* FLASH FLOOD WARNING FOR...

  CENTRAL SAN DIEGO COUNTY IN SOUTHWEST CALIFORNIA... 

  THIS INCLUDES THE AREAS THAT WERE BURNED BY THE WITCH AND 

  POOMACHA FIRES...AND THE CITIES OF...RAMONA...SANTA YSABEL...

  AND SAN DIEGO COUNTRY ESTATES...



* UNTIL 415 PM PDT



* AT 215 PM PDT...SHOWERS AND THUNDERSTORMS WITH HEAVY RAIN WERE

  MOVING ACROSS THE CENTRAL SAN DIEGO COUNTY INLAND VALLEYS...

  FOOTHILLS AND MOUNTAINS...INCLUDING THE AREAS THAT WERE BURNED BY 

  THE POOMACHA AND WITCH FIRES. 



* THUNDERSTORMS HAD HEAVY RAINFALL RATES IN EXCESS OF ONE INCH PER 

  HOUR. THIS ACTIVITY WILL CONTINUE MOVING SOUTHEAST AT 25 MPH.  

 

IN ADDITION TO FLASH FLOODING...RAINFALL IS EXPECTED TO CAUSE DEBRIS 

FLOWS IN THE POOMACHA AND WITCH BURN AREAS ACCORDING TO THRESHOLDS 

PROVIDED BY THE USGS. AREAS AFFECTED INCLUDE VALLEY CENTER...

HIGHWAY 78 BETWEEN ESCONDIDO AND RAMONA...AND SANTA YSABEL. 



RESIDENTS AND MOTORISTS IN AND BELOW RECENTLY BURNED AREAS SHOULD BE 

ALERT TO HEAVY MUD AND DEBRIS FLOWS WHICH MAY BLOCK ROADS AND 

CULVERTS. POTENTIALLY DANGEROUS FLOODING AND PROPERTY LOSS COULD 

RESULT IN AREAS WHERE RUNOFF IS RESTRICTED OR BLOCKED. ADDITIONAL 

RAINFALL AMOUNTS OVER ONE INCH ARE POSSIBLE IN THE WARNED AREA.



THE WATERSHEDS BURNED THIS FALL ARE PARTICULARLY SUSCEPTIBLE TO FLASH

FLOODS AND DEBRIS FLOWS DURING RAINSTORMS. A SHORT PERIOD OF EVEN

MODERATE RAINFALL ON A BURNED WATERSHED CAN LEAD TO DEBRIS FLOWS.

RAINFALL THAT IS NORMALLY ABSORBED INTO HILLSLOPE SOILS CAN RUN OFF

ALMOST INSTANTLY AFTER VEGETATION HAS BEEN REMOVED BY WILDFIRE. THIS

CAUSES MUCH GREATER AND MORE RAPID RUNOFF THAN IS NORMAL FROM CREEKS

AND DRAINAGE AREAS. THE HIGHLY ERODIBLE SOILS IN A BURN SCAR ALLOW

FLOOD WATERS TO ENTRAIN LARGE AMOUNTS OF ASH, MUD...BOULDERS...AND

UNBURNED VEGETATION. WITHIN THE BURNED AREA AND DOWNSTREAM...THE

FORCE OF RUSHING WATER...SOIL AND ROCK CAN DESTROY CULVERTS...

BRIDGES...ROADWAYS AND BUILDINGS...POTENTIALLY CAUSING INJURY OR

DEATH.



LAT...LON 3337 11683 3308 11656 3285 11640 3276 11651

      3288 11677 3289 11684 3297 11701 3321 11715

TIME...MOT...LOC 2109Z 180DEG 0KT 3317 11691



$$



LAVIS

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