Damaging Wind in California, August 21, 2003

INTERIOR CENTRAL CALIFORNIA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HANFORD CA
245 PM PDT THU AUG 21 2003

UPPER LOW DEPICTED BY WV IMAGERY NEAR 33N/126W NOW ACCELERATING AND
TURNING NORTHEAST AS AN UPPER TROUGH DIGS BEHIND IT. THIS LOW IS
PROGGED BY THE 12Z MODELS TO APPROACH THE COAST TONIGHT AND CROSS
NORCAL ON FRIDAY. AS THE LOW CROSSES NORCAL...THE UPPER FLOW WILL
TURN SOUTHWEST AND MONSOONAL MOISTURE WILL BE PUSHED OUT OF THE
CWFA. HAVE FOLLOWED THE GFS TIMING AS IT IS THE FAVORED MODEL TODAY
SINCE IT HAS HAD THE BEST HANDLE WITH THE PLACEMENT ON THE OFFSHORE
LOW...AS IT OFTEN DOES WITH OFFSHORE FEATURES. AT THIS TIME...KHNX
88D IS INDICATING SCATTERED THUNDERSTORMS ACROSS THE SOUTHERN SIERRA
NEVADA AND TEHACHAPI MOUNTAINS AND ISOLATED THUNDERSTORMS ACROSS THE
CENTRAL AND SOUTHERN SAN JOAQUIN VALLEY. TODAY/S STORMS HAVE NOT BEEN
THE BIG RAIN MAKERS THAT SOME OF YDAY/S STORMS WERE SINCE THE
EASTWARD PROGRESSION OF THE OFFSHORE LOW HAS INCREASED STEERING
CURRENTS ACROSS CENTRAL CA. WITH MOISTURE PROGS AND PROJECTED
SOUNDINGS INDICATING A MOIST AND UNSTABLE ATMOSPHERE PROGGED OVER
CENTRAL CA THROUGH THIS EVENING...WILL KEEP MENTION OF SCATTERED
T-STORMS THROUGH THE EVENING...SLOWLY TAPERING OFF OVERNIGHT. WILL
ALSO KEEP THE GOING FLASH FLOOD WATCH FOR THE MOUNTAINS AND KERN
DESERTS RIDE AS HIGH PW/S SUGGEST THAT SOME T-STORMS MAY PRODUCE
HEAVY RAINS. EXPECT T-STORMS TO GRADUALLY DIMINISH ACROSS THE AREA
OVERNIGHT AS THE ATMOSPHERE BECOMES MORE STABLE. WITH A DRY SOUTHWEST
FLOW PREVAILING FRIDAY...WILL KEEP MENTION OF T-STORMS CONFINED TO
THE SOUTHERN SIERRA NEVADA NORTH OF KINGS CANYON WHERE PROGGED 18Z
MESO MAXIMUM CAPES FOR FRIDAY RANGE FROM 100 TO 400 J/KG. ELSEWHERE
DECREASING MOISTURE WILL ALLOW FOR SKIES TO GRADUALLY CLEAR OUT. HIGH
PRESSURE IS THEN PROGGED TO REBUILD OVER CENTRAL CA FROM THE DESERT
SOUTHWEST DURING THE WEEKEND. AS THE LOW CROSSES TO OUR NORTH
FRIDAY...STRENGTHENING ONSHORE P-GRADS WILL ALLOW FOR SOME MARINE AIR
TO SPILL INTO THE SAN JOAQUIN VALLEY WHICH WILL INHIBIT WARMING
ACROSS THE LOWER ELEVATIONS UNTIL SUNDAY. ACROSS HIGHER ELEVATIONS...
DAYTIME TEMPERATURES WILL BEGIN TO WARM SATURDAY AS
HEIGHTS/THICKNESSES RISE WITH MAINLY CLEAR SKIES AND A DRY
ATMOSPHERE. EXPECT FURTHER WARMING ACROSS ALL OF THE CWFA SUNDAY AS
GFS INDICATES 850 MB TEMPERATURES WARM UP BY AROUND 2 DEG C. HAVE
STAYED GENERALLY CLOSE TO THE MAV FOR TEMPERATURES.

FOR THE EXTENDED-FORECAST PERIOD...MONDAY THROUGH THURSDAY...THE
MEDIUM-RANGE MODELS ARE IN GENERAL AGREEMENT WITH THE UPPER-LEVEL
RIDGE REBUILDING BEHIND THE SHORT-WAVE TROUGH THAT TRAVERSED THE
PACIFIC NORTHWEST. THIS WILL ALLOW TEMPERATURES TO REBOUND TO ABOVE
NORMAL WITH DRY CONDITIONS. ANOTHER UPPER-LEVEL SHORT-WAVE TROUGH IS
FORECAST TO MOVE THROUGH PACIFIC NORTHWEST AND NORTHERN CALIFORNIA
TUESDAY NIGHT AND WEDNESDAY...LOWERING 500-MB HEIGHTS OVER CENTRAL
CALIFORNIA FROM 5860 METERS TO 5830 METERS. THIS WILL BRING A BRIEF
COOLING TREND TO THE REGION BEFORE THE RIDGE QUICKLY REBUILDS FOR
WARMER TEMPERATURES. THE WEATHER WILL REMAIN DRY THROUGH THE
EXTENDED FORECAST PERIOD...WITH SOME CLOUDS OVER THE MOUNTAINS AND
DESERTS AT TIMES AS PUSHES OF HIGH-LEVEL MONSOONAL MOISTURE ARE
CARRIED INTO CENTRAL CALIFORNIA BY THE ANTICYCLONIC FLOW AROUND THE
RIDGE.

.HNX...FLASH FLOOD WATCH THROUGH 900 PM FOR ZONES 95>99 (KERN
COUNTY MOUNTAINS AND DESERTS...AND THE SIERRA FROM YOSEMITE TO THE
KERN COUNTY LINE).

DS/SANGER

CAZ089>099-221230-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE HANFORD CA
530 AM PDT THU AUG 21 2003

THIS HAZARDOUS WEATHER OUTLOOK IS FOR THE CENTRAL CALIFORNIA
INTERIOR.

.DAY ONE...TODAY.

THERE IS A CHANCE OF THUNDERSTORMS THIS AFTERNOON AND THIS EVENING
FOR THE SOUTHERN SIERRA NEVADA...THE KERN COUNTY MOUNTAINS...AND THE
KERN COUNTY DESERTS. A FLASH FLOOD WATCH HAS BEEN ISSUED FOR THESE
AREAS UNTIL 900 PM TONIGHT. REFER TO (WGUS66 KHNX - FFAHNX) FOR
FURTHER DETAILS. ISOLATED THUNDERSTORMS ARE POSSIBLE ACROSS THE
CENTRAL AND SOUTHERN SAN JOAQUIN VALLEY THIS AFTERNOON AND TONIGHT.

.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY.

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...

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