000 FXUS66 KHNX 300850 AFDHNX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SAN JOAQUIN VALLEY - HANFORD CA 150 AM PDT SAT AUG 30 2008 .DISCUSSION...HIGH CLOUDS ASSOCIATED WITH CONTINUING CONVECTION OVER SOUTHERN ARIZONA AND NORTHERN SONORA PLAYED HAVOC WITH TEMPERATURE TRENDS OVER THE MOUNTAINS AND DESERTS FRIDAY. TEMPERATURES IN THE KERN COUNTY DESERTS WERE DOWN A FEW DEGREES FROM THURSDAY...AND SEVERAL MOUNTAIN STATIONS /INCLUDING LAKE ISABELLA...SHAVER LAKE... AND GIANT FOREST/ WERE NEAR PERSISTENCE. IN THE CENTRAL AND SOUTHERN SAN JOAQUIN VALLEY...THE WARMING TREND WAS IN FULL FORCE. FRESNO WAS ONLY 2 DEGREES OFF NOT ONLY ITS RECORD HIGH FOR FRIDAY /109 IN 1915/ BUT ALSO ITS RECORD HIGH MINIMUM /76 IN 1915/...WHILE BAKERSFIELD WAS ONLY A DEGREE SHY OF ITS RECORD HIGH MINIMUM OF 78 /SET IN 1931/. FRIDAY WAS THE HOTTEST DAY OF THE CURRENT STRING OF TRIPLE-DIGIT DAYS IN THE CENTRAL AND SOUTHERN SAN JOAQUIN VALLEY. SATELLITE LOOPS SHOW THE GULF OF ALASKA TROUGH HAS MOVED TO 134W ON ITS TREK TOWARD BRITISH COLUMBIA. BY 05Z...THE MARINE LAYER HAD DEEPENED TO AROUND 1500 FEET AT FORT ORD...AND 0630Z WINDS OVER THE SAN LUIS RESERVOIR WERE GUSTING TO 25 MPH. AT 07Z...WINDS AT TRAVIS AFB HAD INCREASED TO 21 KTS WITH A PEAK WIND OF 26 KTS. THE MARINE LAYER WILL CONTINUE TO DEEPEN TODAY AS THE TROUGH APPROACHES CENTRAL CALIFORNIA. THE MODELS CONTINUE TO FORECAST 850-MB TEMPERATURES TO FALL 6 C FROM 00Z SUNDAY TO 00Z MONDAY...WITH ANOTHER 2 C COOLING THROUGH 00Z TUESDAY. THE COMBINATION OF MARINE AIR AND SYNOPTIC COOLING SHOULD DROP TEMPERATURES 5-6 DEGREES TODAY...AND ANOTHER 10-12 DEGREES SUNDAY. HOWEVER...HIGH CLOUDS OVER CENTRAL CALIFORNIA TODAY WILL ADD A COMPLICATION. WHILE THE CLOUDS WILL REDUCE SOLAR HEATING...THEY ALSO WILL KEEP LOWS THIS MORNING A BIT WARMER THAN ORIGINALLY FORECAST..PROVIDING A WARMER BASE FOR TODAY/S TEMPERATURES. IT IS POSSIBLE THAT THE SOUTHERN HALF OF THE CENTRAL CALIFORNIA INTERIOR COULD BE A DEGREE OR TWO WARMER THAN FORECAST. THE NAM-12 FORECASTS 850-MB DEWPOINTS TO REACH +8 C ALONG THE SOUTHERN SIERRA NEVADA CREST AND OVER THE SOUTHERN KERN COUNTY DESERT THIS AFTERNOON...INDICATING THAT SOME MID-LEVEL MONSOONAL MOISTURE WILL REACH THE HANFORD WARNING/FORECAST AREA. SURFACE COMPUTED LIFTED INDEXES OVER THESE AREAS ARE FORECAST TO BE BETWEEN 0 AND -2..WITH SURFACE COMPUTED CAPES UP TO 400 JOULES/KG. WHILE THESE CONVECTIVE PARAMETERS ARE MARGINAL...CANNOT RULE OUT THE POSSIBILITY OF A THUNDERSTORM OR TWO OVER THE MOUNTAINS AND DESERTS AND WILL KEEP THE SLIGHT CHANCE POPS FOR THIS AFTERNOON AND EVENING. THE TROUGH WILL LIFT NORTHEAST TUESDAY AS AN UPPER-LEVEL RIDGE BUILDS IN THE EASTERN PACIFIC. THIS WILL BRING A WARMING TEND FOR THE COMING WEEK WITH CENTRAL AND SOUTHERN SAN JOAQUIN VALLEY TEMPERATURES RISING BACK INTO THE 90S...WITH THE WARMEST SPOTS AGAIN REACHING AROUND 100. && .AVIATION...VFR CONDITIONS WILL PREVAIL ACROSS THE CENTRAL CALIFORNIA INTERIOR THROUGH 12Z SUNDAY. && .AIR QUALITY ISSUES... ON SATURDAY AUGUST 30 2008...UNHEALTHY IN KERN AND TULARE COUNTIES. UNHEALTHY FOR SENSITIVE GROUPS IN FRESNO COUNTY. FURTHER INFORMATION IS AVAILABLE AT VALLEYAIR.ORG. && .HNX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ PUBLIC...SANGER AVN/FW...DS WEATHER.GOV/HANFORD