Program Status for Saturday, 24 February 2001 : IOP 14

winds: 300deg, 14kt
air temp: -13.0degC
dewpt temp: -18.5degC
mix rat: 1.5 g/kg

    P(mb)  Ht(m)  T(degC)  Td(degC) ff(kt) dd(deg)
    550    4903    -13.9     -15.7    30     227
    600    4242    -11.2     -13.8    18     282
    650    3621     -7.4     -10.7    15     288
    700    3046     -3.0      -6.4    15     260
    750    2490      0.1      -0.2    20     271
    800    1973      3.2       2.3    23     282
    850    1472      5.8       0.5    21     282
    900    1006      8.9     -12.1    19     288
    925     779      9.2      -0.1    14     312
    950     560     10.1       5.7    11     327
    975     342     11.5      10.1    10     322

As P3 has been observing it, rainband has moved very little; almost stationary.

    P(mb)  Ht(m)  T(degC)  Td(degC) ff(kt) dd(deg)
    537     -      -15.5     -17.5    -      -
    672     -       -5.3      -7.0    -      -
    700    3059     -3.7      -5.2   14      275
    791     -        1.4       0.3    -      -
    850    1498      5.6       2.3   21      255
    878     -        6.8       5.5    -      -
    913     -        9.0       5.9    -      -
    925     801      9.6       6.8   27      260
   1000     148     13.6      12.4   24      240
   1018-SFC         14.8      13.3   16      235

As P3 has been observing it, rainband has moved very little; almost stationary.

winds: 265deg, 27kt
air temp: -15.4degC
dewpt temp: -17.4degC
mix rat: 1.8g/kg

Are currently exploring what we consider to be the trailing cold front. Just made a drop south of the rainband location. Will relay drop information when it becomes available.

winds: 225deg, 24kt
air temp: -15.7degC
dewpt temp: -17.8degC
mix rat: 1.8g/kg

The remainder of the mission will be mapping the structure of the trailing cold front offshore.

winds: 339deg, 14kt
air temp: 11.6degC
dewpt temp: 7.3degC
mix rat: 6.5g/kg

Current thinking is to end chase of offshore IR feature and head south to possible trailing cold front in order to sample it. Will drop an AXBT in ~5 minutes and turn toward the south.

No echoes were apparent at low levels below the offshore IR "wave" feature.

winds: 355deg, 13kt
air temp: 11.1degC
dewpt temp: 7.7degC
mix rat: 6.6g/kg

On our westward leg, the surface pressure has been gradually rising, inconsistent with cyclogenesis in region of what appears to be a "baroclinic leaf" in IR imagery near 126W.

As of 0507 UTC, no echoes can be seen out to 200 km west of P3 (32.40N, 123.44W).

winds: 341deg, 12kt
air temp: 11.2degC
dewpt temp: 7.3degC
mix rat: 6.5g/kg

winds: 328deg, 11kt
air temp: 11.5degC
dewpt temp: 8.0degC
mix rat: 7.1g/kg

winds: 260deg, 8kt air temp: 6.1degC
dewpt temp: 3.3degC
mix rat: 5.7g/kg

Have finished looking in Santa Barbara channel and are now focusing on feature offshore. Will be using 32.75N, 125W as the center point w/ a radius of operation of about 100 miles about the center point.

winds: 84deg, 28kt
air temp: 7.2degC
dewpt temp: 5.7degC
mix rat: 6.0g/kg

winds: 104deg, 29kt
air temp: 8.3degC
dewpt temp: 7.7degC
mix rat: 6.8g/kg

winds: 167deg, 16kt
air temp: 10.5degC
dewpt temp:7.6degC
mix rat:6.7g/kg

air temp: 6.0degC
dewpt temp: 0.5degC
mix rat: 4.4g/kg

0425z
Last hour's precipitation...

Ventura Co...
Santa Paula Creek -- 0.20
Matilijia Dam -- 0.10
Nordhoff Ridge -- 0.31

Santa Barbara Co...
La Cumbre Peak -- 0.12
Montecito -- 0.11

0415z IR image shows that back edge of the possible baroclinic leaf is approaching 32.75n/125w. Continuing to move east at around 65 kt, and using linear extrapolation, the feature should be near the coast by 0730-0800z. Coldest cloud tops around the area in question continue to be -54C.

Dutter

0358z
Looks like baroclinic leaf at 127w is moving east at about 60 kt. Not as much cloud enhancement with the wave now compared to an hour ago. Quick look at the MesoEta and it seems like the model does not have any baroclinicity in the area in question.

0348z

03z IR picture continues to show cloud tops of -51C about 90 miles west of SBA and 150 miles west of SBA. However...radar from KVBX shows little shower activity offshore with more widespread showers along the the eastern coastal sections of Santa Barbara County. No rainfall reports from Santa Barbara County over the past hour ending at 03z...but in Ventura County, 0.16 reported at Nordhoff Ridge, La Granada Mtn -- 0.20, Sycamore Cyn Dam -- 0.12. Goleta profiler reported east winds at 35 kt at 600m with Simi Valley reporting east winds at 20 kt from 700m to 900m.

Dutter

0258Z
IR Satellite shows enhancement near the developing wave at 31.8n/126.6w with cloud tops of -51C. Front might have slowed a little...with the front remaining to the north of Point Conception. KSMX reports winds of 16010kt at 03z and the Channel Island buoys still report easterly winds at 24-26g30kt. Some precipitation reports over the past two hours ending at 02z are:

Santa Barbara Co... San Marcos Pass: 0.12 Gibralter Dam: 0.16

Ventura Co... Nordhoff Ridge: 0.20 NF Matilija Creek: 0.32

Not much precipitation over Orange and LA Counties over the past couple of hours...even though water vapor shows best plume of mid level moisture continuing over that area.

Dutter

0150Z
Latest Obs from the area...

METAR KMRY 250154Z 19005KT 10SM OVC055 12/07 A2987 RMK AO2 SLP127 T01170072

METAR KSMX 250151Z 15014KT 10SM BKN033 BKN046 OVC080 11/08 A2992 RMK AO2 RAB13E49 SLP134 P0000 T01060078

METAR KSBA 250153Z 07009KT 8SM OVC023 09/09 A2995 RMK AO2 RAE0055B37E51 SLP142 P0001 T00940094

METAR KLAX 250150Z 09011KT 2SM -RA BR BKN013 OVC017 09/08 A3003 RMK AO2 SFC VIS 2 1/2 RAB0053 SLP170 P0003 T00890078

IR satellite shows some enhanced cloud tops (-50C) at 33.7n/122.6w and moving east...most likely associated with the front. KVBX 88D shows only scattered showers at best over the Santa Barbara area. Continuing to see weak development 32n/127w...moving east at 45-50 kt. Feature still looks very weak...but it may be enough to hold up the front slightly the wave approaches the coast. Best moisture plume still centered over L.A. and Orange Counties...with KVTX 88D continuing to show the best returns to the east and south of Oxnard.

0108Z
Looks like best rain has shifted a little further south than what we were thinking this morning. The KVTX 88D is now showing the best returns to the south and east of Oxnard. Satellite and buoy obs show the front approaching Point Conception...with an axis of deep moisture extending from 30n/130w northeast through Orange County. The 18z MesoEta now shows the front slowly moving through Oxnard by 09z with the Theta-E axis centered over eastern Ventura County by that time. However...to complicate matters, latest satellite pictures show a possible wave forming along the front near 32N/128W. GOES winds show a 100+ knot jet moving into the area which is stronger than what the MesoEta depicted, and might be helping the development of the wave. No sign of development from buoy or ship observations now, but will continue to monitor. If this this trend continues...the front may slow down as the wave moves eastward...which may help to cause more rainfall over the Santa Ynez and Santa Monica Mountains. Stay Tuned. Also...at Buoys 54 and 53 in the Santa Barbara Channel the winds remain 08024KT. More observations shortly.

Dutter

Feb 24 1035 PST
LATEST ETA INITIALIZED FEATURES ACROSS THE EAST PACIFIC WELL THIS MORNING. LATEST RADAR IMAGES OUT OF KMUX SHOW THE FRONT APPROACHING THE COAST AT 1755Z...WITH THE FRONT MOVING THROUGH THE MONTEREY BAY BY 1900Z. WATER VAPOR AND IR SATELLITE SHOW PLENTY OF MOISTURE WITH THIS SYSTEM. A SUBTROPICAL TAP IS NOTED WITH SSMI PRECIPTABLE WATER AHEAD OF THE SYSTEM OF WELL OVER AN INCH. THE UPPER LEVEL SYSTEM IS PROGGED TO APPROACH THE NORTHERN CALIFORNIA COASTLINE TODAY AND TONIGHT...WITH THE FRONT SLOWING DOWN AFTER IT MOVES SOUTH OF BIG SUR. HIGH 850MB THETA-E AHEAD OF THE FRONT (AROUND 305K) WITH PRECIPTABLE WATER AROUND AN INCH OVER CENTRAL AND SOUTHERN CALIFORNIA MEANS EXCESSIVE RAINS ARE POSSIBLE FROM PT CONCEPTION SOUTHWARD TO LOS ANGELES TONIGHT. ETA QPF AROUND AN INCH TONIGHT OVER THE SANTA YNEZ MOUNTAINS SEEMS PRETTY REASONABLE...ESPECIALLY GIVEN THE STRONG UPSLOPE FLOW AND THE SLOWER SOUTHWARD PROGRESS OF THE FRONT NEAR POINT CONCEPTION. THE UPPER LEVEL SYSTEM STOPS IT'S EASTWARD PROGRESSION TONIGHT AND THEN SLOWLY MOVES SOUTH ON SUNDAY WHILE THE JET DIGS ON THE WEST SIDE OF THE LOW. THE FRONT SLOWLY MOVES THROUGH LOS ANGELES BY 00Z MONDAY...BUT PLENTY OF MOIST AIR IS STILL STREAMING INTO EXTREME SOUTHERN CALIFORNIA WITH 850 MB THETA-E RIDGING AND PRECIPTABLE WATER AROUND AN INCH. CONTINUED STRONG UPSLOPE FLOW...AND A STRONG VORT MAX ROUNDING THE BASE OF THE TROUGH INTO SOUTHERN CALIFORNIA BY 06Z MONDAY...SHOULD MEAN ADDITIONAL HEAVY RAINS FROM L.A. SOUTHWARD THROUGH MONDAY MORNING.

INTERESTING TO NOTE OVER NORTHERN CALIFORNIA...THE BODEGA BAY PROFILER IS SHOWED A VERY LOW MELTING LEVEL THIS MORNING (AROUND 700 M)...AND STRONG EASTERLY FLOW. POSSIBLY SOME COLD TRAPPED AIR...DUE TO EVAPORATIVE COOLING FILTERING EASTWARD AND INTO THE COASTAL PLAIN. THAT IS PROBABLY WHY NORTHERN CALIFORNIA HAVE LOWER SNOW LEVELS THAN WHAT THE MODELS SHOWED.

FOR THE EXTENDED...A QUICK LOOK AT THE MRF SHOWS LITTLE CHANGE FROM PREVIOUS THINKING. IT CONTINUES TO SHOW THE JET STREAM FOCUSED MORE ON THE PACIFIC NORTHWEST...ESPECIALLY WEDNESDAY THROUGH SATURDAY. ONE STORM IS PROGGED BY THE MRF TO AFFECT WASHINGTON STATE WEDNESDAY...WITH ANOTHER POTENTIALLY STRONGER SYSTEM THURSDAY INTO FRIDAY.

DUTTER