FXUS66 KHNX 140406
AFDHNX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JOAQUIN VALLEY - HANFORD CA
905 PM PDT TUE JUL 13 2004

.SHORT TERM...FOR THE CENTRAL CALIFORNIA INTERIOR...AFTERNOON
TEMPS STAYED BELOW THE CENTURY MARK IN MOST SJ VLY LOCALES 
TODAY...THANKS TO A SHALLOW MARINE INTRUSION LAST NIGHT. 
EVIDENCE OF THIS MARITIME INFLUENCE STILL EXIST IN THE SJ VLY
THIS EVENING WITH TEMP TRENDS AVERAGING A FEW DEGREES LOWER THAN 
24 HRS AGO. THE MARINE LAYER REMAINS PRETTY SHALLOW THIS EVE...
GENERALLY ABOUT 1500 FT DEEP ACCORDING TO THE 00Z OAK SOUNDING.
ONSHORE GRADIENTS HAVE DIMINISHED SOME SINCE LAST NIGHT...AND
ARE CURRENTLY NEAR 7.5 MB BETWEEN SFO AND LAS. ALTHO RELATIVELY
WEAK...IT APPEARS WE WILL NEVER COMPLETELY LOSE THE ONSHORE FLOW
THRU THE SAC DELTA DURING THE NEXT 24 TO 48 HRS...IN PART BECAUSE 
OF AN UPPER LEVEL TROF POISED OVER THE EASTERN PACIFIC.  THAT BODES 
WELL FOR THE SJ VLY...AND IT MIGHT AGAIN KEEP TEMPS FROM CLIMBING
INTO THE TRIPLE DIGITS IN MOST LOCALES WED AND PERHAPS THURSDAY.

HOWEVER...THE ERN PAC TROF WILL NOT BE THE ONLY WEATHER PLAYER
IN OUR PATTERN THIS WEEK. A STRONG RIDGE OF HIGH PRESSURE ALOFT 
WILL REMAIN ANCHORED OVER THE FOUR CORNERS REGION FOR THE DURATION
OF THE WEEK. MONSOONAL MOISTURE CIRCULATING AROUND THIS AREA OF HIGH 
PRESSURE WILL BE MOVING NORTHWESTWARD FROM OLD MEXICO. CURRENT WATER
VAPOR IMAGERY SUGGESTS THAT THE LEADING EDGE OF IT IS ALREADY INTO 
SE CA. ADDITIONALLY...MOISTURE ASSOCIATED WITH TROPICAL STORM BLAS 
IS ALSO BEGINNING TO GET INVOLVED IN THE SE FLOW ALOFT. IT WILL BE
NO SURPRISE TO SEE CONVECTION FIRE UP OVER THE DESERTS OF SE CA
OVERNIGHT. THIS IS WHERE WE WILL HAVE TO KEEP OUR EYES PEELED
DURING THE NEXT 12-18 HRS AS MONSOON MOISTURE CONTINUES TO FLOW 
NORTHWESTWARD. RIGHT NOW OUR FORECASTS SEEM TO BE COVERED PRETTY 
WELL FOR THE KERN CO MTNS AND DESERT...BUT THERE IS A CONCERN THAT
ISOLD TSTMS COULD BEGIN IN THESE AREAS EARLIER THAN NOON WED. MIDNITE
FORECASTER MAY NEED TO SPEED UP ARRIVAL OF CONVECTION IN THE KERN CO
MTNS AND DESERT IF THIS MONSOONAL SURGE DOES NOT SLOW DOWN. 

AM ALSO CONCERNED THAT THE TSTM THREAT CONTINUES THRU WED NIGHT
IN THESE AREAS...A TIME WHEN HISTORICALLY THE MONSOON BECOMES MOST
ACTIVE. AT ANY RATE...AS THE ERN PAC TROF APPROACHES THE WEST 
COAST...TROPICAL MOISTURE WILL CONTINUE TO BE DRAWN NORTHWARD INTO 
CA THU THRU FRI. THIS WILL TURN THE HIGHER ELEVATIONS INTO A
BREEDING GROUND FOR ISOLD TO SCATTERED TSTMS DURING THIS PERIOD...AND
NOT EXCLUSIVELY DURING THE AFTN/EVE HRS. IN THE SJ VLY...THE MOST 
NOTICEABLE CHANGE IN THE WEATHER BY LATE WEEK WILL BE THE HIGHER 
HUMIDITY AND PROBABLY SOME ALTOCUMULUS. THE GFS IS TRYING TO SUGGEST
THAT EVEN THOUGH STEERING WINDS ALOFT SHIFT TO A MORE WESTERLY 
DIRECTION BY SATURDAY...THE TROPICAL REMAINS OF BLAS WILL BE IN A 
FAVORABLE POSITION OUT OVER THE PACIFIC TO GET DRAWN INTO CENTRAL CA 
THIS WEEKEND BETWEEN THE FOUR CORNERS HIGH AND THE UPPER LEVEL 
TROUGH ALONG THE PAC NW COAST. IN OTHER WORDS...MONSOONAL MOISTURE
COULD VERY WELL LINGER OVER CENTRAL CA THROUGH DAY 5.     
   
.LONG TERM...FROM PREVIOUS DISCUSSION...FOR SATURDAY THROUGH 
TUESDAY...MODELS REMAIN IN GOOD AGREEMENT WITH LARGE SCALE PATTERN 
ESPECIALLY IN THE BEGINNING OF THE PERIOD. FOR SATURDAY...DOMINANT 
FEATURES INCLUDE A LARGE UPPER RIDGE HOLDING ON OVER THE ROCKY 
MOUNTAINS WITH A HIGH CENTERED OVER THE FOUR CORNERS AND AN UPPER 
LOW JUST OFF THE PACNW COAST. THIS PATTERN WILL ALLOW FOR ONE MORE 
DAY OF ISOLD MONSOONAL CONVECTION OVER DESERT AND MOUNTAIN AREAS. 
THE UPPER LOW OPENS UP AND MOVES INLAND ON SAT NIGHT INTO 
SUNDAY...DISPLACING THE UPPER HIGH SLIGHTLY SOUTH AND EASTWARD. A 
RETURN TO A MORE STABLE SOUTHWEST FLOW ALOFT WILL PUT THE KIBOSH ON 
THE MONSOONAL THREAT BEGINNING SUNDAY. SOME SYNOPTIC COOLING WILL 
CONTRIBUTE TO MORE SEASONAL TEMPERATURES THROUGHOUT THE 
VALLEY...WITH MID TO UPPER 90S FOR MOST LOCATIONS SUNDAY THROUGH 
TUESDAY. IN ADDITION...THE MARINE LAYER WILL GAIN IN DEPTH ONCE THE 
UPPER LOW MOVES ONSHORE AND WILL CONTRIBUTE TO THE COOLING. HOW MUCH 
SO WILL DEPEND ON THE STRENGTH OF THE PRESSURE GRADIENT. WILL 
MONITOR MOVEMENT OF T.S BLAS...BUT LIKELY ONLY EFFECTS WILL BE SOME 
UPPER MOISTURE ADVECTED BY RELATIVELY WEAK UPPER FLOW PATTERN.

&&

.HNX WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

DURFEE/HARTY