We are in the middle of a fairly significant cold snap here in Southern California. Cold air continues to dive south at mid and upper levels from western Canada to SoCal. Low level flow today is shifting from northwest to north, but the gradients from L.A. to Bakersfield and Daggett are not impressive. BFL to LAX has been about -2 to -3 millibars (offshore, NW flow), and DAG to LAX was weakly onshore this morning and about neutral towards sunset. Skies remain crystal clear to mostly clear, with some occasional insignificant fractocu and high clouds.
Wind at Cheeseboro, a hilltop station just north of Agoura, was persistent all night and into the mid-morning hours, from the NW to NNW, at speeds of 15 mph on average with gusts in the 20s. Nevertheless, the Conejo Valley-area low spots and frost pockets were near calm and cold for most of the night, and minimums were very close to the minimums from the previous night —- into the mid 20s for the most part. In contrast to the night of the 10th/11th, however, the cold temperatures were longer lived last night (11th/12th). Temperatures were already in the upper 20s by 11 p.m. (Friday night) at the wind-protected Agoura and Westlake Village and Calabasas low spots. At Westlake Village/EW0033/Press, near the lake, the minimum temperature was 25F. It was 32F or lower from 9:30 p.m. PST to 7:40 a.m., or about 10 hours of freezing weather. It was 28F or colder from 11:30 p.m. to 7:30 a.m., an 8-hour period. And, it was 25F to 27F from 12:30 a.m. to 7:20 a.m., almost 7 hours of mid-20s.
At my place (WLV/Reid), it was 26F again, and the adjacent undeveloped canyon frost pocket to the west was 23F, a degree warmer than the previous morning. A Weather Underground station in Newbury Park reported 24F.
Last night an upper-level system helped to keep the wind active along the hilltops and in the wind-exposed valley areas, and I think this helped to keep the temperatures in the coldest spots from plunging even more. Also, dew points were not especially low —- around 20F overnight at Cheeseboro. Even though Westlake Village/EW0033 had dropped to 28F at midnight, it only dropped another 3 degrees before the sun appeared, 7 and a half hours later. On the previous night, a sporadic wind was blowing around midnight and the temperature was fluctuating in the low to mid 30s around midnight. But, the wind quit by 2 or 3 a.m., even at Cheeseboro, and the temperature fell to 25F at WLV/EW0033 before sunrise.
In the San Fernando Valley, there was generally more wind and mixing on the morning of the 12th, and minimum temperatures were a little warmer than on the previous night. The exception was for the more wind-protected stations in Woodland Hills, where the temperature dropped a little below freezing.
The minimums on the 12th in the San Fernando Valley were in the 30s, well above record territory and not particularly noteworthy, thanks to the wind and the mixing. The mid-20s minimums in the coldest parts of the Conejo Valley and Santa Monica Mountain frost pockets are near, or slightly warmer than, what might be expected for the coldest temperature of the year on average.
min/max temps, January 11 and 12, Conejo Valley area stations, including unofficial valley-bottom and canyon frost pockets
Westlake Village/Northgate/Reid 26/54, 26/56 (near Westlake and Hillcrest)
WLV frost pocket just W of Northgate 22/mm, 23/mm (1/4 mile west of Westlake and Hillcrest)
WLV frost pocket near Westlake H. S. 23/52 (Schoolhouse Canyon)
Westlake Village/EW0033/Press 25/52, 25/54
Westlake Village/North Ranch/WU 30/51, 34/52
Calabasas DW3850 28/58, 28/59
Calabasas frost pocket near City Hall 24/mm,
Agoura Hills/Lobo Canyon/WU 25/51, 25/53
Agoura Hills/Lost Hills/WU 29/55, 27/56
Malibu Canyon/RAWS 27/58, 25/58
Thousand Oaks/Lang Ranch/WU 33/50, 35/53
Newbury Park DW1941 29/53, 29/56
Newbury Park/WU 26/63, 24/64 (Borchard and Michael St, max temps too high, mins look okay)
Moorpark Home Acres/DW0912 26/56, 26/57
Simi Valley DW3685 30/52, 30/55 (east end of Simi Valley)
Camarillo AP 32/57, 33/58
min/max temps, January 11 and 12, western San Fernando Valley and vicinity
Woodland Hills/Pierce College 31/54, 33/56
Woodland Hills/Gonzales Dr/WU 30/52, 30/53
Woodland Hills/CW2288 30/53, 30/54
Woodland Hills/CW0623 35/57, 36/58 (near Warner Center)
Winnetka/WU 32/53, 34/55
Chatsworth/DW0345 35/52, 39/56
Northridge/CSUN 34/52, 39/55
Encino/Hesby Oaks/WU 33/54, 34/56
Van Nuys AP 34/51, 36/53
Burbank AP 38/53, 37/54
Studio City/DW6087 35/55, 37/57
Topanga/DW5544 24/52, 26/53
min/max temps, January 11 and 12, nearby hilltop stations
Cheeseboro/Agoura/RAWS 35/52, 37/52 elev 1707′
Calabasas/Park Belmonte/WU 37/50, 39/50 elev 1438′
Malibu/DW5145 37/44, 39/47 elev 1715′
Malibu DW2363 34/44, 34/44 elev 2450′
Topanga/RAWS 36/52, 36/55 elev 1600′
Porter Ranch/DW4339 36/47, 35/51 elev 1634′
Oat Mountain 28/36, 27/40 elev 3693′
pasted below are the max/min temp lists for SoCal for Jan 12, 2013:
SOUTHERN CALIFORNIA TEMPERATURE AND PRECIPITATION SUMMARY
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
410 PM PST SAT JAN 12 2013
:
HIGH TEMPERATURE PAST 12 HOURS AS OF 4PM PST TODAY
LOW TEMPERATURE PAST 18 HOURS AS OF 4PM PST TODAY
PRECIPITATION PAST 24 HOURS. M DENOTES MISSING. T DENOTES TRACE.
** DENOTES 4PM-4PM REPORTING STATION
:
.BR LAX 0112 P DH16/TAIRZS/TAIRZI/PPDRZZ
:
: ID : STATION : HIGH/ LOW / PCPN
:
: …LOS ANGELES COUNTY COAST…
:
AVNC1: AVALON HARBOR : 54 / 42 / 0.00
AIDC1: AVALON INLAND : 56 / 37 / 0.00
CVRC1: **CULVER CITY : M / M / M
GTCC1: GETTY CENTER : 55 / 40 / 0.00
HHR : HAWTHORNE : 58 / 40 / 0.00
LAX : LA AIRPORT : 57 / 43 / 0.00
CQT : LA DOWNTOWN/USC : 57 / 39 / 0.00
LGB : LONG BEACH ARPT : 57 / 36 / 0.00
RDOC1: REDONDO BEACH : 57 / 38 / 0.00
SMO : STA MONICA ARPT : 56 / 41 / 0.00
1L2 : STA MONICA PIER : 53 / 45 / M
TOAC1: TORRANCE : 56 / 38 / 0.00
UCLC1: UCLA : 56 / 42 / 0.00
:
: …LOS ANGELES COUNTY VALLEYS…
:
BUR : BURBANK : 54 / 37 / 0.00
CHTC1: CHATSWORTH : 56 / 39 / 0.00
CSUC1: NORTHRIDGE : 55 / 39 / 0.00
PSAC1: PASADENA : 56 / 37 / 0.00
POMC1: POMONA/FAIRPLEX : 54 / 30 / 0.00
JBLC1: SAN GABRIEL : 56 / 36 / 0.00
SAUC1: SAUGUS : 55 / 32 / 0.00
VNY : VAN NUYS : 53 / 36 / 0.00
WPCC1: WOODLAND HILLS : 56 / 33 / 0.00
:
:…LOS ANGELES COUNTY MOUNTAINS AND DESERTS…
:
ATNC1: ACTON : 45 / 23 / 0.00
WJF : LANCASTER : 44 / 17 / 0.00
MWSC1: MOUNT WILSON : 39 / 18 / 0.00
PMD : PALMDALE : 44 / 18 / 0.00
SDB : SANDBERG : 37 / 23 / M
:
: …VENTURA COUNTY…
:
CMA : CAMARILLO : 58 / 33 / 0.00
FILC1: FILLMORE : 57 / 31 / 0.00
LOKC1: LOCKWOOD VLY YARD : 40 / 12 / 0.00
OJAC1: OJAI : 55 / 25 / 0.00
LOXC1: OXNARD – NWS : 57 / 34 / 0.00
SMVC1: SIMI VALLEY : 56 / 33 / 0.00
VTUC1: VENTURA : 57 / 36 / 0.00
:
: …SANTA BARBARA COUNTY…
:
CYMC1: NEW CUYAMA : 42 / 26 / 0.00
LPC : LOMPOC : 55 / 30 / 0.02
SBA : SBA ARPT/GOLETA : 55 / 33 / 0.00
SBSC1: SBA CITY FD : 55 / 38 / 0.00
SMX : SANTA MARIA : 54 / 30 / 0.00
IZA : SANTA YNEZ : 52 / 28 / 0.00
:
: …SAN LUIS OBISPO COUNTY…
:
HSCC1: **HEARST CASTLE : M / M / M
1MB : MORRO BAY : 54 / 39 / 0.00
PRB : PASO ROBLES : 50 / 28 / T
PISC1: PISMO BEACH : 55 / 40 / 0.00
1SL : PORT SAN LUIS : 53 / 43 / 0.00
SBP : SLO AIRPORT : 54 / 36 / 0.00
SBPC1: SLO – CAL POLY : 52 / 34 / 0.00
.END
————–
:SOUTHWESTERN CALIFORNIA TEMPERATURE AND PRECIPITATION SUMMARY
:NATIONAL WEATHER SERVICE SAN DIEGO CA
:430 PM PST SAT JAN 12 2013
:
:***** PRELIMINARY *****
:
:18 HOUR HIGH AND LOW TEMPERATURES AS OF 4 PM TODAY.
:PRECIPITATION FOR THE PAST 24 HOURS. M DENOTES MISSING.
: T DENOTES TRACE OF PRECIPITATION
:
.BR SGX 0112 P DH16/TAIRZS/TAIRZI/PPDRZZ/SDIRZZ
:
: ID : STATION ELEV : HIGH / LOW / PCPN / SNODEP
: FEET INCHES
:
: …COASTAL AREAS…
:
YBLC1: YORBA LINDA 350 : 58 / 33 / 0.00 /
FUL : FULLERTON AIRPORT 96 : 59 / 35 / 0.00 /
ANAC1: ANAHEIM 335 : M / M / M /
STAC1: SANTA ANA 135 : 56 / 36 / 0.00 /
SDHTB: HUNTINGTON BEACH 5 : 56 / 33 / 0.00 /
SNA : JOHN WAYNE AIRPORT 55 : 55 / 35 / 0.00 /
3L3 : NEWPORT BEACH 10 : 57 / 39 / 0.00 /
LAGC1: LAGUNA BEACH 35 : 56 / 42 / 0.00 /
SDDPC: DANA POINT 305 : 52 / 33 / 0.00 /
SDFRH: LAKE FOREST 970 : 57 / 37 / 0.00 /
L34 : OCEANSIDE HARBOR 10 : 53 / 34 / 0.00 /
OKB : OCEANSIDE AIRPORT 28 : 56 / 27 / 0.00 /
VSTC1: VISTA 330 : 55 / 30 / 0.00 /
CRQ : CARLSBAD AIRPORT 328 : 54 / 37 / 0.00 /
SDETS: ENCINITAS 270 : 54 / 38 / 0.00 /
SOL : SOLANA BEACH 75 : M / M / M /
DMRC1: DEL MAR 100 : 56 / 38 / 0.02 /
NKX : MIRAMAR 477 : 56 / 35 / 0.01 /
MYF : MONTGOMERY FIELD 420 : 55 / 36 / 0.00 /
SWDC1: SEA WORLD SAN DIEGO 10 : M / M / M /
SAN : SAN DIEGO 15 : 56 / 42 / 0.00 /
L13 : CABRILLO NATL MNMT 364 : 58 / 40 / 0.00 /
SDNAC: NATIONAL CITY 25 : M / M / M /
CVAC1: CHULA VISTA 56 : 60 / 36 / 0.00 /
NRS : IMPERIAL BEACH 23 : 55 / 39 / 0.00 /
SDM : BROWN FIELD 525 : 55 / 34 / 0.00 /
:
: …INLAND AREAS…
:
ONT : ONTARIO 943 : 55 / 28 / 0.00 /
CNO : CHINO 652 : 55 / 23 / 0.00 /
SDALO: RANCHO CUCAMONGA 1940 : 51 / 32 / 0.00 /
SDSBO: SAN BERNARDINO 1050 : 54 / 33 / 0.00 /
AJO : CORONA 531 : M / M / M /
RAL : RIVERSIDE AIRPORT 818 : 56 / 30 / 0.00 /
UCRC1: RIVERSIDE 986 : 58 / 30 / 0.00 /
RIV : RIVERSIDE MARCH 1542 : 50 / 22 / 0.00 /
BUO : BEAUMONT 2680 : 49 / 26 / 0.00 /
EORC1: ELSINORE 1285 : 54 / 27 / 0.00 /
HEMC1: HEMET 1811 : 50 / 30 / 0.00 /
SDTEC: TEMECULA 1020 : 56 / 29 / 0.00 /
SDFBK: FALLBROOK 680 : 54 / 34 / 0.00 /
SDSMP: SAN MARCOS 630 : 56 / 36 / 0.00 /
ESCC1: ESCONDIDO 645 : M / M / M /
PSQC1: SAN PASQUAL VALLEY 255 : 58 / 28 / 0.00 /
RNM : RAMONA AIRPORT 1393 : 52 / 23 / 0.00 /
SGX : RANCHO BERNARDO 690 : 55 / 35 / 0.02 /
POWC1: POWAY 648 : 56 / 30 / 0.00 /
ALPC1: ALPINE 1695 : 51 / 30 / 0.03 /
SDLAM: LA MESA 500 : 55 / 37 / 0.02 /
SDSNL: SANTEE 425 : 57 / 32 / 0.01 /
ELJC1: EL CAJON 405 : 55 / 34 / M /
SDRSC: RANCHO SAN DIEGO 400 : 56 / 33 / 0.00 /
:
: …MOUNTAIN AREAS…
:
ECSC1: EL CARISO 2730 : 50 / 32 / 0.00 /
SOX : SANTA ANA RADAR 3092 : 47 / 32 / 0.00 /
WRIC1: WRIGHTWOOD 5980 : 26 / 7 / M / M
SDARN: LAKE ARROWHEAD 5180 : 35 / 14 / 0.00 /
BBLC1: BIG BEAR LAKE 6760 : M / M / M / M
SDBDN: BALDWIN LAKE 6770 : 24 / -1 / M /
SDAOK: ANGELUS OAKS 5800 : 31 / 14 / 0.01 /
SDPCV: PINE COVE 6299 : 29 / 15 / 0.03 /
IDYC1: IDYLLWILD 5380 : M / M / M / M
NZAC1: ANZA 3939 : 40 / 18 / 0.00 /
PYNC1: PINYON PINES 4060 : 45 / 25 / 0.00 /
PLRC1: PALOMAR MOUNTAIN 5550 : 37 / 19 / 0.00 / M
JULC1: JULIAN 4240 : 39 / 24 / 0.00 /
MLNC1: MOUNT LAGUNA 5920 : 29 / 18 / T /
CZZ : CAMPO COOP 2615 : 48 / 19 / 0.01 / 2
:
: …DESERT AREAS…
:
HESC1: HESPERIA 3055 : 42 / 23 / 0.01 / 0
APLC1: APPLE VALLEY 2780 : 44 / 18 / 0.00 / M
PSP : PALM SPRINGS 425 : 55 / 37 / 0.00 /
IDOC1: INDIO -21 : 57 / 40 / 0.00 /
TRM : THERMAL -117 : 58 / 34 / 0.00 /
BROC1: BORREGO 805 : 55 / 33 / 0.00 /
OCTC1: OCOTILLO WELLS 390 : 60 / 39 / 0.00 /
TYEC1: JOSHUA TREE N.P. 1975 : M / M / M / M
BLH : BLYTHE 397 : 53 / 39 / 0.00 /
IPL : IMPERIAL -56 : 57 / 36 / 0.00 /
.END
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