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2001 - Monterey, CA
July 13-14 2000 (Boulder, CO)
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Program Status for Sunday, 25 February 2001

Status | Observations | Forecast Discussion | Flight Plan | Soundings Status

Status (Updated: 1600 PST Sunday, 25 Feb)
Next Update: Monday, 26 Feb 1500 PST.
Sunday, February 25 P3 take-off at 1530 PST.
G-4 due in Monterey at 1815 PST.
Monday, February 26 No weather briefing.
Hard down day for the G-4.
No P3 flight.
Tuesday, February 27 Hard down day for the P3.

Status | Observations | Forecast Discussion | Flight Plan | Soundings Status

Observations
0734 UTC at 35.82N, 121.58W, 753mb:
heading: 342deg at 8000 ft (returning to MRY)

winds: 123deg, 13kt
air temp: -3.8degC
dewpt temp: -4.7degC
mix rat: 3.8g/kg

We've climbed to 8000 ft and are on our way home.

0706 UTC at 34.13N, 120.95W, 979mb:
heading: 346deg at 1000 ft (rounding Pt Conception)

winds: 345deg, 8kt
air temp: 9.8degC
dewpt temp: 6.1degC
mix rat: 6.1g/kg

0601 UTC
0533 UTC P3 spiralling down at 31.13N, 117.96W during spiral down...

    P(mb)   Ht(m)   T(degC)  Td(degC)  ff(kt)  dd(deg)
     750    2461     -2.0       -         5     240
     800    1939      1.1      0.7        4     170
     850    1460      4.3      3.1        2     291
     875    1218      5.4      3.9        1      35
     900     994      7.7      5.1        4     140
     925     761      9.2      6.1        7     159
     950     544     10.7      7.4        9     188
     975     323     11.4      9.1       13     221

Now at 1000 ft, heading to pt 6 (~14min).

0522 UTC Drop#19 at 31.0N, 118.02W:

   P(mb)   Ht(m)   T(degC)  Td(degC)  ff(kt)  dd(deg)
   1015-SFC   -      12.6      10.5       -      -
    1000     129     11.6      10.0       -      -
     925     777      7.6       5.7       -      -
     850    1469      3.6       2.5       -      -
     700    3019     -5.9     -13.9      12     310
     500    5570    -22.7     -26.0      32     230
0504 UTC Drop#18 at 29.26N, 117.57W:

    P(mb)   Ht(m)   T(degC)  Td(degC)  ff(kt)  dd(deg)
   1015-SFC   -      14.4      10.7      19     155
    1000     124     13.2      10.2      17     155
     925     776      9.4       4.4      13     225
     850    1471      3.8       1.9      15     240
     700    3025     -4.5      -7.5      16     255
     500    5590    -22.1     -32.1       -      -
0502 UTC at 29.21N, 117.93W, 465mb:
heading: 354deg at 20000 ft (to pt 6)

winds: 223deg, 33kt
air temp: -25.7degC
dewpt temp: -26.6degC
mix rat: 1.0g/kg

0450 UTC Drop#17 at 27.92N, 117.85W:

    P(mb)   Ht(m)   T(degC)  Td(degC)  ff(kt)  dd(deg)
   1016-SFC   -      15.8      10.2      12     185
    1000     132     14.4       8.8      13     185
     925     785      8.8       5.4      12     225
     850    1480      4.6       0.2      12     270
     700    3041     -4.1     -22.1      25     240
     500    5610    -21.3     -37.3      38     240
0445 UTC at 27.80N, 117.85W, 465 mb:
heading to pt 6 (drop#17 in 20 min)

winds: 231deg, 50kt
air temp: -23.5degC
dewpt temp: -49.6degC
mix rat: 0.1g/kg

0424 UTC Drop#16 at 28.5N, 119.4W:

    P(mb)   Ht(m)   T(degC)  Td(degC)  ff(kt)  dd(deg)
   1015-SFC   -      15.2      10.2       8     255
    1000     128     14.0       9.8       8     250
     925     780      8.8       6.1      10     240
     850    1477      5.8      -0.2       9     265
     700    3034     -5.3      -9.4      14     285
     500    5590    -22.7     -31.0      40     250
0408 UTC Drop#15 at 29.0N, 121.0W:

    P(mb)   Ht(m)   T(degC)  Td(degC)  ff(kt)  dd(deg)
   1015-SFC   -      14.4      10.4      12     265
    1000     128     13.2      10.1      11     280
     925     779      8.4       6.4      12     245
     850    1473      3.8       1.7      12     245
     700    3026     -3.5     -23.0      26     255
     500    5580    -24.9     -45.0      39     260
0353 UTC Drop#14 at 29.5N, 122.4W:

    P(mb)   Ht(m)   T(degC)  Td(degC)  ff(kt)  dd(deg)
   1015-SFC   -      13.8       9.7       8     360
    1000     125     12.6       8.0       8     360
     925     774      8.2       1.2      11     310
     850    1465      2.0      -2.9      12     310
     700    3010     -5.9     -27.0      26     250
     500    5550    -25.1     -38.0      40     250
0338 UTC Drop#13 at 30.0N, 124.0W:

   P(mb)   Ht(m)   T(degC)  Td(degC)  ff(kt)  dd(deg)
   1016-SFC   -      11.4       8.0       -      -
    1000     134     11.0       6.7      11     340
     925     779      5.8       4.2      11     350
     850    1465      0.8      -0.9      11     320
     700    3003     -7.7      -9.5      13     285
     500    5530    -24.3     -43.0      44     285
0337 UTC at 30.01N, 124.08W, 465 mb:
heading: 84deg at 20000 ft (moving to pt 4)

winds: 293deg, 45kt
air temp: -27.0degC
dewpt temp: -56.6degC
mix rat: 0.0g/kg

0326 UTC Drop#12 at 30.0N, 125.2W:

   P(mb)   Ht(m)   T(degC)  Td(degC)  ff(kt)  dd(deg)
   1017-SFC   -      13.6       6.6      14     340
    1000     139     12.2       4.2      13     340
     925     785      6.4       1.5      12     335
     850    1473      1.6      -3.6      13     315
     700    3006     -9.5     -11.8      17     295
     500    5550    -22.9     -38.0      42     300
0307 UTC at 30.00N, 127.28W, 465mb:
heading: 89deg at 20000ft (moving to pt 4)

winds: 307deg, 50kt
air temp: -24.4degC
dewpt temp: -49.1degC
mix rat: 0.1g/kg

Have turned at pt 3' and are now heading to pt 4.

0300 UTC Drop#11 at 30.0N, 125.5W:

    P(mb)   Ht(m)   T(degC)  Td(degC)  ff(kt)  dd(deg)
   1017-SFC   -      13.6       4.6      15     335
    1000     143     12.2       4.2      16     335
     925     790      6.4       0.4      16     335
     850    1476      1.4      -7.6      18     330
     700    3012     -7.1     -31.0      24     325
     500    5570    -20.9     -49.0      48     310
0247 UTC at 29.44N, 126.70W, 465mb:
heading: 307deg at 20000ft (moving to pt 3')

winds: 304deg, 52kt
air temp: -24.4degC
dewpt temp: -46.4degC
mix rat: 0.1g/kg

0243 UTC Drop#10 at 29.3N, 126.5W:

    P(mb)   Ht(m)   T(degC)  Td(degC)  ff(kt)  dd(deg)
   1017-SFC   -      14.0       7.0      15     340
    1000     140     12.8       5.8      17     330
     925     788      6.6       3.5      15     325
     850    1477      2.2      -1.5      17     315
     700    3013     -6.9     -30.0      26     305
     500    5570    -21.3     -54.0      45     305
0228 UTC Drop#9 at 28.6N, 125.4W:

    P(mb)   Ht(m)   T(degC)  Td(degC)  ff(kt)  dd(deg)
   1016-SFC   -      14.6      10.0      16     325
    1000     138     13.0       8.2      18     330
     925     787      7.2       4.4      11     320
     850    1476      1.4       0.0      11     305
     700    3019     -5.1     -36.0      33     275
     500    5580    -22.0     -47.0      45     290
0220 UTC at 28.32N, 125.04W, 465mb:
heading: 305deg at 20000ft (moving to pt 3')

winds: 291deg, 45kt
air temp: -25.8degC
dewpt temp: -42.8degC
mix rat: 0.2g/kg

0211 UTC at 28.01N, 124.43W, 465 mb:
heading: 283deg at 20000 ft (moving to pt 3')

winds: 286deg, 49kt
air temp: -26.2degC
dewpt temp: -40.2degC
mix rat: 0.2g/kg

Have released drop south of pt 2 to sample atmosphere south of convective line.

Now heading to a revised pt 3 (pt 3') located at 30N, 127W.

0207 UTC Drop#8 at 27.98N, 124.5W:

    P(mb)   Ht(m)   T(degC)  Td(degC)  ff(kt)  dd(deg)
   1016-SFC   -      16.6       7.6      12     360
    1000     132     15.4       7.4      12     355
     925     786      9.4       6.3      12     335
     850    1482      4.4       1.2      20     310
     700    3045     -2.3     -32.0      32     275
     500    5670    -21.9     -40.0      43     275
0158 UTC At 28.75N, 124.80W, 465 mb:
heading: 190deg at 20000 ft , just turned at pt 2

winds: 286deg, 45kt
air temp: -26.9degC
dewpt temp: -36.2degC
mix rat: 0.4g/kg

Moving south toward convective line seen out cockpit window beyond pt 2.

0151 UTC Drop#7 at 28.95N, 124.95W:

    P(mb)   Ht(m)   T(degC)  Td(degC)  ff(kt)  dd(deg)
   1016-SFC   -      14.4       5.4      10     345
    1000     135     13.2       5.2      12     335
     925     784      7.6       0.6      13     315
     850    1474      2.4      -2.3      18     300
     700    3019     -4.9     -43.0      29     265
     500    5570    -23.7     -38.0      43     280
0145 UTC Drop#6 at 0145UTC at 29.42N, 125.06W:

    P(mb)   Ht(m)   T(degC)  Td(degC)  ff(kt)  dd(deg)
   1016-SFC   -      13.8       6.8      17     335
    1000     132     12.6       6.6      17     335
     925     780      6.6       4.2      13     335
     850    1467      1.4       0.2      16     315
     700    3007     -6.5     -41.0      32     280
     500    5560    -23.5     -40.0      43     285
0135 UTC at 30.25N, 125.38W, 465mb:
heading: 169deg at 20000 ft (2 min to drop#5)

winds: 306deg, 52kt
air temp: -26.0degC
dewpt temp: -54.8degC
mix rat: 0.0g/kg

0121 UTC Drop#4 at 0121UTC at 31.0N, 125.7W:

    P(mb)   Ht(m)   T(degC)  Td(degC)  ff(kt)  dd(deg)
   1016-SFC   -      13.2       5.2       -      -
    1000     133     12.0       5.0       -      -
     925     778      6.2       0.2       -      -
     850    1465      1.2      -2.5       -      -
     700    2998     -8.9     -14.9      19     285
     500    5520    -24.1     -59        43     310
0119 UTC Drop#3 at 0119 UTC at 31.95N, 126.02W

   P(mb)   Ht(m)   T(degC)  Td(degC)   ff(kt)  dd(deg)
    1016-SFC         12.6      5.6        13      315
    1000     135     11.2      5.7        14      315
     925     780      5.6      0.0        16      315
     850    1465      0.4     -5.4        15      330
     700    2994     -9.3    -25.3        15      295
     500    5510    -24.9    -52.0        36      325
0118 UTC 31.82N, 125.97W, 465mb:
heading: 166deg at 20000ft (moving to drop 4)

winds: 321deg, 45kt
air temp: -26.8degC
dewpt temp: -53.5degC
mix rat: 0.1g/kg

0100 UTC at 32.67N, 125.47W, 464 mb:
heading: 219deg at 20000 ft (20 min from drop#4)

winds: 319deg, 22kt
air temp: -29.5degC
dewpt temp: -53.6degC
mix rat: 0.1g/kg

0056 UTC
The view from the P3.
0052 UTC Drop#2 at 0052 UTC at 33.75N, 124.55W

    P(mb)  Ht(m)  T(degC)  Td(degC)  ff(kt)  dd(deg)
   1015-sfc  -     11.0       8.4      10      300
    1000    124    10.2       8.5      09      310
     925    767     4.8       4.8      07      320
     850   1452     0.6       0.5      10      315
     700   1985    -8.7      -0.3      09      305
     500   5500   -27.3     -15.3      12      230
0049UTC at 33.42N, 124.83W, 464 mb:
heading: 215deg at 20000 ft (30 min to drop#4)

winds: 211deg, 15kt
air temp: -31.0degC
dewpt temp: -36.1degC
mix rat: 0.4g/kg

0017UTC Drop#1 at 35.36N, 123.16W

   P(mb)   Ht(m)   T(degC)    Td(degC)   ff(kt)   dd(deg)
   1015-sfc  -      11.6          6.6      2        210
   1000      125    10.4          5.9      2        205
    925      768     5.2          0.4      2        295
    850     1452    -0.4         -8.4      1        350
    700     1983    -7.9        -39.0      8        215
    500     5510   -26.9        -48.0     20        205
0032 UTC at 34.44N, 123.98W, 464 mb:
heading: 217deg at 20000 ft (10 min to drop#2)

winds: 194deg, 25kt
air temp: -30.7degC
dewpt temp: -42.6degC
mix rat: 0.2g/kg

0012 UTC at 35.62N, 122.92W, 464mb
heading: 218deg at 20000ft to drop#1 (3min)

winds: 200deg, 23kt
air temp: -31.2degC
dewpt temp: -44.7degC
mix rat: 0.2g/kg

2350 UTC After take-off at MRY:

    P(mb) Ht(m) T(degC) Td(degC) ff(kt) dd(deg)
     850   1455   1.6     -4.3     8      172
     925    777   6.5     -0.7    10      205

About 20 minutes until drop#1.

Status | Observations | Forecast Discussion | Flight Plan | Soundings Status

Forecast Discussion
0615z
Just noticed a RAWS site just up the Bell Canyon from San Juan Capistrano (southeast Orange County) had a gust to 56 mph from the northeast (same orientation as the canyon) at 03z. Was gusting to 47 mph as recently as 05z, but gusts had died down to 30 mph by 06z. Future research may want to concentrate on the legitamacy of the observation or on a reason for the gusts other than the pressure gradient given the gradient across the Santa Ana Mountains was only about 1-2 mb at the time. The apparent gust happened about the same time that San Diego's wind was backing in direction from south to southeast due to an apparent strengthening of the offshore low.
Haner

0546z
I was just looking at the Experimental RUC at 03Z and noticed that it developed the low circulation further south off the San Diego Coast than what the observations where indicating. Perhaps as you fly northward, later updates to the RUC will make an adjustment.

Precipitation estimates are not even close to reality. It is still showing the heaviest precipitation over northern baja the next few hours with local three hour amounts less than one half inch. Three hour output from O6Z RUC image for precipitaion estimates shows less than 0.05 inches from LA county northward. Sepulveda Dam picked up 0.40 inches last hour. RUC is generally showing less than a quarter inch from orange county southward with an isolated amount between one quarter to one hour inch near the border of Orange and San Diego County.

Also the 500 mb hieght/vort field did not pick up on the vort feature I mentioned in earlier discussions that the mso eta picked up on over the Santa Monica Bay. RUC has strongest vort lobe west of point conception...near the flight path you took to point one. Latest ETA run has this area in a weak NVA at 06Z. I'm not sure but there may be a correlation to the flight path that was taken in why this is showing up.

0540z
A surface low pressure center is now located in Santa Monica Bay south of LAX. Winds at Buoy 46047 (Tanner Bank) have now backed from northwest to WNW, suggesting the low may now be passing that latitude. The lowest surface pressures yet with this system are now being observed at buoy 46025 with 1011.1 mb. As the low pressure center moves northeast toward the LA/Orange County coasts, heaviest precip should shift inland through midnight and the front will finally pass southeast through San Diego. The 04-05z precip highlights include:

Ventural County Coast:
     Conejo Creek above Hwy 101...0.43"

Ventura County (western valleys):
     N Fork Matilija Creek...0.24"
     Matilijia Dam...0.20"

Ventura County (eastern valleys):
     Santa Clara at Piru...0.20"

Ventura County (mtns):
     Nordhoff Ridge...0.47"

LA Metro:
     Lechuza FS...0.28"
     Beverly Hills...0.25"
     Hollywood Resvr...0.20"
     La Habra Heights...0.20"

LA County (s fernando and s clarita vlys):
     sepulveda Dam...0.40"
     Agoura...0.31"
     Chatsworth Rsvr...0.24"

LA County (mtns and foothills)
     Opids Camp...0.21"

San Diego County (deserts)
     Coyote Creek...0.16"
     Ocotillo Wells...0.16"

0400z
Here are the latest 02-03z rainfall highlights:

Santa Barbara County (south coast)
     Montecito...0.41"

Ventura County (mountains)
     Tommy's Creek...0.28"
     Nordhoff Ridge...0.20"

LA Metro
     Big Rock Mesa...0.24"
     Ballona Creek at Sawtelle...0.20"
     Beverly Hills...0.16"

LA County (S Fernando and S Clarita Valleys)
     Sepulveda Dam...0.20"
     Schoolhouse D.B...0.16"

LA County (San Gabriel Valley)
     Fremont Hdqs...0.31"
     Eagle Rock Reservoir...0.28"
     Puddingstone Divide...0.24"

LA County(Mtns and foothills)
     Live Oak Dam...0.24"
---------
Now for the 03-04z highlights:

Santa Barbara County (mtns and foothills)
     San Antonio Ridge...0.20"

Ventura County (western valleys)
     Fagan Canyon east...0.24"

Ventura County (eastern valleys)
     Santa Susana Pass...0.20"
     Nordhoff Ridge...0.28"

LA Metro:
     Beverly Hills...0.31"
     Compton...0.21"

La County (San Fernando Valley)
     Canoga Park...0.28"
     Sepulveda Dam...0.24"

LA County (San Gabriel Valley)
     Santa Fe Dam...0.16"

Winds in coastal San Diego County have now been backing for the past 2-3 hours, suggesting that the front is either slipping south or that low pressure is strengthening offshore, or both. Suspect it is actually a combination of both. The RUC model actually shows the front slipping south of San Diego late this evening. The precipitation has also creeped west into far eastern Santa Barbara County as the whole system pivots counter-clockwise, but the passage of the main vort max and upper support later this evening should reverse this trend with the bulk of precip moving inland overnight.

Other relatively minor feature of interest is the broken band of showers over western Santa Barbara County extending offshore south from Point Arguello. Believe this is being caused by convergence of easterly winds in the Santa Barbara Channel and northwest winds sliding down the westward-facing coasts of San Luis Obispo and Santa Barbara Counties. Could be worth checking out if this feature still exists on the flight back north. Surface obs due show a weak reflection of a possible surface trough extending up the coast from Point Arguello.

Otherwise, the whole system continues to take on a more negative tilt all the time with low-level cloud elements (and likely the front) behind the vort max now shifting southeast. IR satellite imagery shows a broken line of cumulus located from 30.0N 121.6W through 28.4N 123.8W to 27.5N 125.6W. This is far removed from the main precip shield but is still of mild interest.

0409
I talked with LA forecaster a little while ago and he felt that the surface low was increasing offshore. Surface observations At 03Z Torrance 12015G20KT...LAX 0918G23KT...Santa Monica Basin Bouy 02015KT and Avalon(AVX) 17008KT. Note the circular pattern over Santa Monica Bay!

The forecaster in San Diego so far has had mostly light rain with no problems to report.

Montecito picked up another 0.41 inches last hour in southwest Santa Barbara County. LA forecaster is considering issuing Flood Statement for southeastern Santa Barbara County .

0250Z
LA office has issued a flood advisory for ventura and la counties through 10 pm.

San Diego office has issued a Flash Flood Watch for tonight for Orange and San Diego Counties...the Inland Empire and surrounding Mountians.

Radar images indicate good enhancment taking place over the Santa Monica Bay near where meso eta indicated the center of the vort max would be by 03Z. Also a developing line of 40 DBZ extends from just east of San Clemente Island....due south to 75 miles west of Ensenada Mexico. This line has shown very little movment.

In General RADAR shows most precipitation moving almost due north as upper low is slowly becoming more negativly tilted. IR image at 02Z indicates greatest moisture plume extending from near San Nicoles Island/33.4N 119.5W down to 28.9N to 119.5W. IR images shows intermitent enhancements of cloud tops around this line...with embeded heavier cells moving northward as the moisture plume progesses very slowly to the east. Greatest enhancement is currently over San Nicoles Island and moving northward.

Surface observations at 02Z indicate rain has spread further west into Santa Barbara County. Orographics is enhancing preciptation in southern Santa Barbara County...with last hour Montecito recieving 0.40 inches and Mt Calvery 0.31 inches.

In Ventura County Mountains...Nordolf Ridge 0.20 inches. Upper Matilija Canyon 0.24 inches.

In La County heaviest rain continues along the coast with numerous reports around one quarter inch during the past hour. Rainfall rates increase in the San Gabriel Valley with several locations reporting around one quarter inch. In the Mountains the highest report was 0.20 inches at Thompson Creek Dam.

In San Diego County...rainfall amounts ranged from 0.04 to 0.12 inches.

METAR observations indicate surface winds almost south near San Diego and curling to the east at LAX...and remaining east through the Santa Barbara Channel.

0200Z
Compared the 0119Z P3 sounding to the 12z model runs this morning. The P3 temperature profile is about 2C colder at 700 and 500 mb than what the models forecasted. This is consistant with a slightly stronger upper level system...and thus slightly lower surface pressures than what the models forecasted this morning.

Dutter

0135z
To contrast the unidirectional southerly profile mentioned in the last update from the San Diego sounding, the Simi Valley wind profiler has an easterly wind of 10-15 knots through about 2k ft agl, then gradually veers to southerly by about 4k ft agl. Just another sample from the other side of the presumed front. Also, buoy 46047 (Tanner Banks, 137 mi W of San Diego) now shows a MSL of 1012.7 mb which is 1-3 mb lower than models from earlier today were forecasting, so this could be a tad more potent a system than earlier thought. Finally, the last visible satellite pictures of the day show a broken cumulus line (which could be the front) extending WSW from the main rain shield from 31.1N 120.9W through 30.0N 122.0W to 28.8N 123.8W.

0115z
Largest one-hour rainfall reports from 00-01z were along the coast.

Here is a sampling:

LA River at Firestone...0.32"
Compton Creek at Greenleaf...0.30"
LAX International...0.28"

LA 96th and Central...0.24"
Santa Monica...0.20"
San Gabriel/San Fernando Valleys...0.04"-0.31"
Mountain and foothills...0.04-".16"
San Diego coast, foothills and mountains...0.04"-0.16"
    except Oak Flats...0.28"

Heaviest rainfall should move inland in the next hour.

Several interesting things to note this hour. There was a 00z ship report from 38 miles northwest of KSAN with a SSE wind of 35 knots. Also the wind at Avalon (KAVX) has shifted from 14013G19kt to 25009kt from 23z to 01z. IR satellite pictures have also shown an enhancement of cloud tops in the general area of 29.8N 119.9W in the past two hours. Looks like this may be a sign of the approaching strong upper level divergence mentioned in the routine forecast discussion early this afternoon. Finally, the KNKX (San Diego) 00z sounding showed a unidirectional southerly wind profile from the surface to 850 mb (~4.7k ft) with slight veering to SSW above that. As would be expected in a rainy regime, the temperature profile was nearly moist adiabatic.
Haner

2335z
Latest METAR observations indicated light to moderate rain from LA basin southward. At 23Z winds at San Diego from 15016KT...At Avalon 14013G19KT...Calm at Point Mugu...and VRB04KT at Santa Barbara.

Bouy Winds in Santa Barbara Channel...Point Conception 16002KT. East Santa Barbara Channel 12006KT.

Tanner Banks 137 miles west of San Diego or 32.43N/119.32W indicates winds 33008KT.

Radar images indicate back edge of the front a little south of Santa Barbara...with the Heaviest rainfall over LA county as of 2345Z.

18Z meso eta shows vort max centered near 33.6N/119.2W at 03Z with north-south elongation into western Ventura county. Model moves center of vort max to just west of Palos Verdes by 06z or 33.7N/118.6W.

LA forecast office has extended Winter Storm Warning through Monday...with San Diego continuing Winter Storm Warning through tonight.Latest METAR observations indicated light to moderate rain from LA basin southward. At 23Z winds at San Diego from 15016KT...At Avalon 14013G19KT...Calm at Point Mugu...and VRB04KT at Santa Barbara.

Bouy Winds in Santa Barbara Channel...Point Conception 16002KT. East Santa Barbara Channel 12006KT.

Tanner Banks 137 miles west of San Diego or 32.43N/119.32W indicates winds 33008KT.

Radar images indicate back edge of the front a little south of Santa Barbara...with the Heaviest rainfall over LA county as of 2345Z.

18Z meso eta shows vort max centered near 33.6N/119.2W at 03Z with north-south elongation into western Ventura county. Model moves center of vort max to just west of Palos Verdes by 06z or 33.7N/118.6W.

LA forecast office has extended Winter Storm Warning through Monday...with San Diego continuing Winter Storm Warning through tonight.

1340
The main focus today will be in extreme southern California. Current land-based surface observation and the most recent ship reports show a surface front located from near the Orange-San Diego county line offshore to near 30.0N 123.5W with land-based surface winds north of the front from the east and surface winds from the south on the warm side of the front. The latest AMSU data shows PW values of 1-1.1" in the axis of a moisture plume corresponding well with the front. Land-based radars show the heaviest precip moving onshore also co-located with the surface front. An upper trough near 127W is already starting to take on a negative tilt as a 120 knot 300 mb jet digs into the base of the trough. Upper level divergence will increase dramatically this afternoon and evening over the San Diego County and northern Baja coastal regions as this area comes underneath the left exit region of the upper jet and the upper trough takes on more of a negative tilt. Low-level moisture convergence will also be maximized along the low-level boundary and will be the other major forcing factor. There will be little in the way of low-level temperature advection, so isentropic lift should not be a major factor. However, a low-level theta-e axis will gradually shift south from the San Diego coastal areas this afternoon and into the northern Baja region this evening as the upper trough approaches and kicks the front south. Otherwise, models agree in not showing further deepening of the frontal wave approaching the coast this evening, and models agree in not showing any significant low-level jet.

Extended forecast...long-term models agree in building an upper ridge and northerly flow aloft across most of the west coast on Tuesday. The flow across the northern Pacific starts to become more zonal on Wednesday with a system approaching the Pacific northwest coast on Thursday. While there are differences in the organization of that system and even at what latitude it will arrive on the caost, the 12z AVN is in general agreement with the 00z MRF on the timing with the most likely time for operations on Thursday afternoon along the WA/OR coast.

Haner

Status | Observations | Forecast Discussion | Flight Plan | Soundings Status

Flight Plan

Status | Observations | Forecast Discussion | Soundings Status

Sounding Status
25 February
Bodega BaySoundings as event develops.
CazaderoSoundings as event develops.
OaklandSpecial soundings requested at 3, 6, and 9 Z.
RenoNo special soundings requested.
26 February
Bodega BaySoundings as event develops.
CazaderoSoundings as event develops.
OaklandNo special soundings requested.
RenoNo special soundings requested.