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SEPTEMBER 2000 WX REVIEW

Special notes:

Aug30-Sept 2 rain event
Sept. 17-20th heat wave

Starting on Aug 30th, a multi day event featuring first Sub tropical precip (0.16" in Pacifica, however much heavier south and southeast with floods in SE Ca) then a GOA frontal  passage as a huge trough digging offshore down to near 15N forced record rains out of the juicy air in SF on 09/01. Chilly air also resulted in widespread record lo/highs, 6,500 SL in no. Sierra, 7"  of snow on Donner Summit, and a post frontal trough on 09/02  similar in nature to winter time..with scattered Cu and iso shwrs, even some convection inland-however convection was unable to punch through locally though. The locals hills noted with a touch of green early in the month, but a return to dry conditions put the early bloom on hold again. The near all-summer long western wildfires were finally controlled as moisture/cold air  finally worked into into Montana/Idaho/Wash. A second, less potent event occurred between the 15th and 17th, which was related to a persistent deep tough with a moderate cut off low at it's tip flinging low level up from the sub-tropics. A few afternoon convective showers were noted on the aft. of the 16th (a decent short shot in Milpitas around noon), but no lightning to speak of.  
As the upper low drifted offshore, Diablo winds at the surface brought widespread record temps, and peaked at 90.3 on the 18th...by far the highest temp in my records for Sept. ( old record was 87F set last year). Overall, the 90.3 was only the fourth 90+ reading in Pacifica in my records.

Despite the extreme heat waves early (June) and late, the overall cool summer has had many similar characteristics as last year - Tie to La Nina???.....most reads on La Nina say she is virtually gone and near normal SST's are now the norm....but there is no mistaking this September as both warm and summerish aloft and cool, very fall like at the surface...identical to a La Nina pattern.

                   MONTHLY CLIMATOLOGICAL SUMMARY for SEP. 2000


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  59.7  63.4   4:30p  57.6  10:00p   4.5   0.0  0.16   3.9  17.0   6:15a     S
 2  61.8  69.8   2:45p  55.8  10:45p   2.2   0.0  0.00   2.6  13.0   1:45p   SSW
 3  60.1  67.2   2:00p  54.6   3:45a   4.1   0.0  0.00   2.9  16.0   4:00p     S
 4  59.8  65.8   2:15p  54.8   5:15a   4.7   0.0  0.00   3.3  17.0  12:00p     S
 5  60.7  72.4   1:45p  50.7   6:45a   3.4   0.0  0.00   1.9  11.0  12:45p   SSW
 6  67.7  79.4   1:15p  54.8   1:00a   0.0   2.1  0.00   2.1  14.0  10:00a    SE
 7  70.4  84.3  12:45p  57.9  12:00m   0.0   6.1  0.00   2.0  13.0  10:45a   SSW
 8  61.6  74.1   1:30p  53.5   5:15a   1.2   0.0  0.00   2.7  16.0   3:45p     S
 9  59.8  72.0   1:15p  53.1   4:00a   2.5   0.0  0.00   2.1  13.0   2:45p    SE
10  58.9  71.8   2:15p  49.1   4:45a   4.5   0.0  0.00   1.6  11.0   2:15p    NE
11  59.9  72.8   2:00p  49.0   5:45a   4.1   0.0  0.00   1.9   9.0   1:15p   SSW
12  59.7  70.6  12:30p  48.5   7:30a   5.5   0.0  0.00   1.4  11.0   5:15p   SSW
13  71.8  78.2   8:30a  61.1  12:30a   0.0   4.6  0.00   3.8  30.0  10:15p   SSW
14  65.6  72.7   1:00p  60.5  12:00m   0.0   1.6  0.00   3.3  23.0  12:15a   SSW
15  60.7  64.7   5:15p  57.7   7:30a   3.8   0.0  0.03   2.6  14.0   2:45p   SSW
16  59.5  66.9   4:15p  54.2  12:00m   4.4   0.0  0.03   1.6   8.0   1:45a   SSW
17  72.0  85.2   1:30p  54.0  12:30a   0.0   4.6  0.01   2.4  16.0  11:45a    SW
18  78.0  90.3  12:45p  68.5  12:00m   0.0  14.4  0.00   2.2  15.0  11:00a   SSW
19  69.2  84.1   1:00p  62.2   2:15a   0.0   8.2  0.00   1.0   8.0   1:00p   WNW
20  67.9  84.3   2:30p  60.8   5:30a   0.0   7.6  0.00   4.0  24.0   3:45p     S
21  63.5  69.3   2:15p  59.7   7:00a   0.5   0.0  0.00   6.9  31.0   7:15a     S
22  59.6  64.1   3:15p  54.2  12:00m   5.8   0.0  0.02   2.9  20.0  12:15a     S
23  60.5  71.6  11:45a  52.6   6:45a   2.9   0.0  0.01   1.4   9.0  11:15a   ESE
24  60.4  72.0   3:00p  51.7   3:45a   3.2   0.0  0.00   1.6   9.0  12:45p    NW
25  61.5  72.9   1:45p  53.3   4:45a   1.9   0.0  0.00   1.5   9.0  11:45a     E
26  60.1  68.1   2:15p  55.2   2:15a   3.3   0.0  0.00   1.2   9.0  12:45p   SSE
27  61.2  69.0   2:00p  55.5   1:15a   2.8   0.0  0.00   3.3  18.0  12:45p   SSW
28  59.0  61.3   2:15p  57.4   7:15a   5.7   0.0  0.00   3.3  13.0  12:15a   SSW
29  60.7  72.9   2:15p  52.4   5:45a   2.3   0.0  0.00   1.4   9.0   2:15p    NE
30  63.3  75.2   2:15p  55.5   4:00a   0.0   0.3  0.00   1.6  10.0   2:15p   SSW
-------------------------------------------------------------------------------------
    63.1  90.3    18    48.5    12    73.3  49.5  0.26   2.5  31.0    21     SSW


Max >= 90.0:  1
Max <= 32.0:  0
Min <= 32.0:  0
Min <=  0.0:  0
Max Rain: 0.16 ON  9/01/00
Days of Rain: 4 (>.01 in) 1 (>.1 in) 0 (>1 in)
Heat Base:  65.0  Cool Base:  65.0  Method: (High + Low) / 2