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