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JULY 1999 MONTHLY REVIEW

Warm to start the month, cold with drizzle at the end. 4th of July was unusually pleasant, and warm, clear and WINDLESS conditions prevailed. Our coastal weather was primarily dominated by subtle changes in wind flow patterns along the coast.  With the hot spell of early in the month, winds either blew from the NNE, or were light/absent -indicating a slackening  and even slightly offshore pressure gradient between the coast and inland (Sacramento Valley, etc.)  During the second week, wind direction gradually shifted to more typical WSW. But instead of remaining there, troughiness to our north caused winds  to shift to SSW. A prime effect of these SSW winds is to move relatively warmer southern latitude water northward, and SST is now up to 56-58F in the imediate area. The warmer water is quite shallow, but it is sufficiently warm to cap ocean waters and prevent turnover/upwelling. Because the warmer water is jucier air, fog is enhanced, to the point of widespread drizzle along the coast and unseasonably cool temps at times in the valleys. A great example was during the first week, temps in the northern Sac. Valley (Red Bluff) set temp records of 118F. Temps closer to home (Gilroy) got to 113.  However, by the second week,  hi temps in Stockton were in the low to mid 70's...a good 20-25 degrees below normal for this time of year. Despite the locally warming Pacific coast waters, long range ENSO models now show a continuation of La Nina conditions is expected through the Winter of '99-'00. With global atmospheric heat further dissipating after the El Nino of '97-'98, this years La Nina influenced winter may be drier than last...possibly very much drier.  

The monthly raw data is incomplete due to our rabbit eating the Wx station's power cord while we were on vacation.

                   MONTHLY CLIMATOLOGICAL SUMMARY for JUL. 1999


NAME: HOME CITY: Pacifica  STATE: Ca  ELEV: 540'  LAT: 37.36'N  LONG: 122.27'W 


                   TEMPERATURE (°F), RAIN  (in), WIND SPEED (mph)


                                      HEAT  COOL        AVG
    MEAN                              DEG   DEG         WIND                 DOM
DAY TEMP  HIGH   TIME   LOW    TIME   DAYS  DAYS  RAIN  SPEED HIGH   TIME    DIR
------------------------------------------------------------------------------------
 1  60.0  72.5   9:00a  53.4  12:00m   2.0   0.0  0.00   3.8  22.0   3:30p     S
 2  57.0  66.2   9:00a  51.7   5:00a   6.1   0.0  0.00   6.9  21.0   4:00p     S
 3  57.1  63.2   3:00p  52.1   3:00a   7.3   0.0  0.00   6.4  24.0  12:30p   SSW
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31  58.7  60.7  12:30p  55.8  11:30p   6.8   0.0  0.00   5.5  18.0   3:30p     S
-------------------------------------------------------------------------------------
    58.2  72.5     1    51.7     2    22.2   0.0  0.00   0.7  24.0     3     SSW


Max >= 90.0:  0
Max <= 32.0:  0
Min <= 32.0:  0
Min <=  0.0:  0
Max Rain: 0.00 ON  7/01/99
Days of Rain: 0 (>.01 in) 0 (>.1 in) 0 (>1 in)
Heat Base:  65.0  Cool Base:  65.0  Method: (High + Low) / 2