Flash Flood in California, July 14, 2004

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN DIEGO
230 PM PDT WED JUL 14 2004

.SYNOPSIS...MOISTURE IN SOUTHEAST FLOW ALOFT WILL CAUSE SCATTERED
THUNDERSTORMS IN THE MOUNTAINS AND DESERTS TODAY AND THURSDAY...
DECREASING FRIDAY THROUGH SUNDAY. A FEW THUNDERSTORMS COULD DRIFT WEST
OF THE MOUNTAINS THIS AFTERNOON AND THURSDAY AFTERNOON. THUNDERSTORMS
HAVE DEADLY LIGHTNING AND MAY HAVE BRIEF HEAVY RAIN...STRONG GUSTY
WINDS AND HAIL. A SHALLOW MARINE LAYER WILL CAUSE AREAS OF COASTAL LOW
CLOUDS AND FOG IN THE NIGHTS AND MORNINGS. STRONG HIGH PRESSURE ALOFT
WILL CONTINUE HOT WEATHER INLAND...SLOWLY COOLING THROUGH EARLY NEXT
WEEK AS THE HIGH WEAKENS.

&&

.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES.

.SHORT TERM...FORECAST ON TRACK THIS MORNING. LARGE AREA OF MOISTURE
AND CLOUDS APPROACHING FROM THE SE. SRN DESERT DEW POINTS HAVE
INCREASING INTO THE LOW 70S. THE 12Z NKX SOUNDING SHOWED PW INCREASING
TO 1.13 INCH WITH S TO SE WINDS ALOFT RANGING FROM ABOUT 10 KT AT
10000 FT TO 20 KT AT 20000 FT. THERE WAS A MODERATELY STRONG INVERSION
BASED BELOW 1000 FT. WEAK GRADIENTS WITH ONLY ABOUT 2 MB SAN-IPL.

THE MOISTURE MOVING IN FROM THE SE WILL BRING A GOOD CHANCE OF
THUNDERSTORMS TO THE MOUNTAINS AND DESERTS TODAY...ESPECIALLY IN THE
SE PORTION OF OUR AREA. ENOUGH MOISTURE FOR SOME THUNDERSTORMS TO
PRODUCE ENOUGH HEAVY RAIN FOR POTENTIAL FLASH FLOODING...ESPECIALLY
IN THE RECENTLY BURNED AREAS...AND CURRENT FFA LOOKS OK. ELY COMPONENT
TO THE FLOW ALOFT COULD CAUSE A FEW STORMS TO DRIFT W OF THE MOUNTAINS
INTO THE INLAND VALLEYS BUT PROBABLY NOT STRONG ENOUGH TO TAKE THEM
ALL THE WAY TO THE COAST. SOME DISAGREEMENT BETWEEN THE MODELS ON HOW
MUCH MOISTURE WILL REMAIN THU...BUT GENERALLY LOOKS SIMILAR TO TODAY.
MOISTURE THEN SLOWLY DECREASES FRI AND SAT BUT THERE WILL STILL BE A
CHANCE OF AFTERNOON AND EVENING THUNDERSTORMS...MAINLY OVER THE
MOUNTAINS. CONTINUED SHALLOW MARINE LAYER WITH LOCAL DENSE FOG NEAR
THE COAST IN THE NIGHTS AND MORNINGS. CONTINUED HOT INLAND.

.LONG TERM...SLOW DRYING TREND WILL CONTINUE WITH A SLIGHT CHANCE OF
AFTERNOON AND EVENING THUNDERSTORMS IN THE MOUNTAINS INTO SUN.
OTHERWISE...MINOR CHANGES IN MARINE LAYER. SLIGHTLY COOLER WITH LOWER
HEIGHTS.

.SGX WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH...SEE LAXFFASGX.
SPECIAL WEATHER STATEMENT...SEE LAXSPSSGX.

&&

ATKIN

SPECIAL WEATHER STATEMENT...UPDATE
NATIONAL WEATHER SERVICE SAN DIEGO CA
100 PM PDT WED JUL 14 2004

CAZ048-050-055-056-058-060>062-151300-
APPLE AND YUCCA VALLEYS-COACHELLA VALLEY-
RIVERSIDE COUNTY MOUNTAINS-SAN BERNARDINO AND RIVERSIDE COUNTY
VALLEYS-THE INLAND EMPIRE-SAN BERNARDINO COUNTY MOUNTAINS-SAN DIEGO
COUNTY DESERTS-SAN DIEGO COUNTY MOUNTAINS-SAN DIEGO COUNTY VALLEYS-
100 PM PDT WED JUL 14 2004

...THUNDERSTORMS EXPECTED MAINLY OVER THE MOUNTAINS AND DESERTS
THIS WEEK...

MONSOONAL MOISTURE WILL STEADILY INCREASE THROUGH THURSDAY.
THUNDERSTORMS WITH LOCALLY HEAVY RAINFALL ARE POSSIBLE IN THE
MOUNTAINS AND DESERTS TODAY THROUGH FRIDAY...ESPECIALLY DURING THE
AFTERNOONS. FLASH FLOODING WILL BE POSSIBLE. THUNDERSTORMS WILL ALSO
HAVE GUSTY WINDS AND LIGHTNING. A FEW THUNDERSTORMS COULD DRIFT WEST
OF THE MOUNTAINS INTO THE INLAND VALLEYS TODAY OR THURSDAY.

MONSOONAL MOISTURE WILL DECREASE DURING THE WEEKEND WITH DECREASING
THUNDERSTORM CHANCES. DRY WEATHER IS EXPECTED TO RETURN BY EARLY
NEXT WEEK.

PEOPLE SHOULD BE AWARE OF CHANGING WEATHER CONDITIONS THIS WEEK...
ESPECIALLY IN THE MOUNTAINS AND DESERTS DURING THE AFTERNOONS.

X6/ATKIN