Program Status for 10 February 2001

winds 214deg, 25kt
air temp: -6.2degC, dewpt temp: -8.1degC

Temp (C)     Alt (m) MSL      p(mb)
  0            1115            891
 -3            1474            841
 -8            2359            751
-13            3127            680

    P (mb)  T(degC) RH(%) WNDDIR(deg) WNDSPD(m/s)
    580     -23.8   25.5    225.1       13.77
    600     -25.0   42.4    237.7       10.87
    650     -20.2   39.6    265.6        9.35
    700     -16.7   26.9    304.5        7.74
    750     -12.5   26.7    307.4        6.61
    800      -8.7   43.5    324.0        8.14
    850      -5.1   63.6    325.1        9.21
    900      -1.7   72.1    322.2        8.04
    921       0.0   68.6    322.6        7.14
    925       0.3   69.7    323.8        6.82
    950       2.4   66.7    325.9        6.19
    975       4.4   53.3    324.1        7.49
   1000       6.4   50.9    323.8        7.46
   1004       6.8   49.7    319.8        6.63
   splash

     500 mb  -33degC at 41deg20minN, 126degW
     700 mb  -14degC at 40deg56minN, 125deg7minW
     850 mb   -3degC at 40deg50minN, 124deg55minW
     900 mb    0degC at 40deg48minN, 124deg50minW

Temp C  Alt m MSL    p mb
  0      1100        881        
 -3      1557        832
 -8      2344        750
-13      3062        686

Cazadero reports:
S-band radar shows fairly deep cloud, cloud returns from 4.75-5.5 km AGL, precip echo continuously up to 2.5 km AGL.

P(mb)     T(degC)    RH(%)    WND DIR(deg)   WND SPD(m/s)
 700      -12.81     42.4       263.7        10.5
 850       -1.98     90.4       262.0         9.31
1000        8.10     67.8       269.9         7.53

No Lightning strikes on detection system. But several reports from east bay of cloud to cloud lightning.

Convection north of Pt. Reyse does not have any discernible structure. to the south several small bands can be seen moving through the San Francisco coastal waters. Band from 6:19Z image from P-3 is moving southeast and is now gust inland of Point Reyes. Satellite shows good enhancement of the line as it moves inland but Radar still only has a few echoes to 40Dbz.

Most sites in Northern San Francisco Bay reporting .05 to .10 precipitation.

Rain last hour 

                         Eureka         .12
                         Honeydew       .04
                         Venado         .04
                         Cazadero       .02 approximate
                         Bodega bay     .03 approximate

Last discussion for IOP 8.

Ertl

0630 UTC February 11, 2001

No Lightning strikes on detection system but Travis AFB reported TSRA at 6:32z.

Looks like the front has gone past buoy 22 off Cape Mendacino the winds gone from 180 to 290deg but the SLP has not changed much. Looking a satellite image looks like front is along north coast to Fort Bragg then sw at 38.9/124 - 37.3/124.7 - 35.8/128.3

As the front approaches the coast the "gap" in radar coverage from Eureka and San Francisco is filling in.

Satellite derived PW just north of the front shows amounts to .67.

Rain last hour 

                         Eureka         .07
                         Honeydew       .00
                         Venado         .12
                         Cazadero       .10 approximate
                         Bodega bay     .03 approximate

Ertl

0530 UTC February 11, 2001

No Lightning strikes.

Having GOES problems so now good images since 3Z.

Radar does not show a distinct band in Northern CA anymore just large area of showers. Crescent City winds gone from 190 to 220 and SLP has come up a bit. At 5z Crescent City 4sm +RA and .10 rain.

Shower activity likely increasing south of Fort Bragg but being overshot by Radars.

Rain last hour 

                         Eureka         .09
                         Honeydew       .24
                         Venado         .00
                         Cazadero       .04
                         Bodega bay     .06

KMRY TAF

110520Z 110606 16008KT P6SM VCSH SCT020 BKN040
OVC120
TEMPO 0613 5SM SHRA BKN020
FM1300 17012G18KT 4SM RA BR OVC020 WS015/19030KT
TEMPO 1417 21020G28KT 1SM +SHRAPL OVC006

Ertl

0430 UTC February 11, 2001

No Lightning strikes.

Band of echos reached Cape Mendocino a 03:40z. Approaching Eureka and Fort Bragg.

1hr Radar estimated precipitation from Eureka has only a few areas of .1/hr off Cape Mendacino. But Eureka had .10 last hour.

On Satellite highest tops staying north of Pt. Reyes.

Buoy 27 near the Oregon California border has turned from 180deg 15G25kt to 230deg 15G20kt. Other off shore buoys in Northern California still Southerly 15kt ahead or second band.

Rain last hour 

                         Eureka         .10
                         Honeydew       .04
                         Venado         .08
                         Cazadero       .05
                         Bodega bay     .00


 Ertl 

0330 UTC February 11, 2001

No Lightning strikes.

Radar echo intensity over cape Mendocino has diminished but eastern extent continues to increase. The second band now just 20 miles from Cape Mendocino. No new bands evident on IR or Radar just unorganized convection to the northwest.

Highest clouds tops now moving south with the cirrus shield to Monterey Bay with the tops highest tops to Pt. Arena.

Off shore buoys in Northern California still Southerly 15kt gusting to 25kt ahead or second band.

Rain last hour

                         Eureka         .09
                         Honeydew       .12
                         Venado         .00
                         Cazadero       .05 increasing intensity
                         Bodega bay     .03

Ertl

0230 UTC February 11, 2001

No Lightning strikes from coast west.

Strongest Radar returns continue over Cape Mendocino with max near 50Dbz. Line to the south is becoming less organized with a second band to the west approximately 30 miles west of the coast from Crescent city to Cape Mendocino and moving east at approximately 20 kt. This line is very close to the back edge of the higher enhanced clouds...could be front. All coastal buoys ahead of second band still south to southwest. Southern extent of the enhanced clouds on IR has changed little over the last hour with highest clouds north of Fort Bragg.

Winds from Bodega Bay profiler sw to w 5 to 10 kt below 900m.

Last hour Crescent city  .11
          Eureka         .04
          Honeydew       .04
          Venado         .00
          Casadero       .00
          Bodega bay     .01

Ertl

0100 UTC February 11th, 2001

At this time no lightning activity along the coast or over the water. Organised line of convection on radar from just inland Cresent city south over Eureka and then due south to 33nm west of Fort Bragg. Line moving east at 40 kt. Cresent city 01z 3sm +RA and Eureka 10sm -RA Trace. Unorganised convection over SFO bay area.

PACJET IOP#08 Short Term Forecast Discussion
NWS/PACJET Operations Center, Monterey, CA
Saturday, 10 February

Short Term (Sat - Mon)Discussion
Initial analysis of both Avn and Eta were consistent with the recent trend of placing the next upper low too far east. So both models may be a couple hours too fast with the arrival of the cold front to the Northern California coast tonight. Went mainly with the Eta solution as it initialized best with the placement of the vorticity field. The upper low off the Oregon coast will move slowly southeast through Monday and follow a track close to along the California coast. Jet Stream dynamics and orographics look favorable with this system. Precipitation through midnight will be concentrated north of the San Francisco Bay region. Late night through Sunday the jet stream and plume of .75 inch layer precipitable water will be focused on the Santa Lucia range and across to the Southern Sierra Nevada.

Plenty of post frontal shower activity expected Sunday across Northern and Central California. However...the front will become quasi-stationary across Southern California with the best orographic flow in the Santa Ynez mountains northwest of Los Angeles. Showers will diminish across Northern California on Monday while rain continues in Southern California.

Long Term (Tue-Sat) Discussion
Decent agreement on Tuesday amongst the extended range models with the upper low centered over Southern California where showers will continue. Meanwhile, ridging strengthens over the eastern pacific. Significant differences appear on Wednesday. The Euro model is alone in developing a strong and stagnant upper low along the northwest California coast. 12z run of the Avn looks more reasonable in depicting a break between systems on wednesday. Followed by the next upper low dropping south along the east side of the ridge and across Washington wednesday night.

Dry forecast for Thursday through Saturday seems reasonable. However, if the recent model trend of being too far east and too weak with these systems continues then this could be a more active period.

DW