NOAA Environmental Technology Laboratory
PACJET 2001: PACIFIC LANDFALLING JETS EXPERIMENT
U.S West Coast Phase I: January - February 2001
Phase II: January - February 2002
NEW
PACJET 2003 Site
RESOURCES
PACJET 2002 Site
GPS Realtime Water Vapor
GWINDEX
West Coast RUC
ETL Profiler Network
Press Materials
BACKGROUND
About Pacjet
CALJET Summary
Societal Impacts and User Input
Linkages to National Priorities
USWRP
  Data Assimilation Implementation Plan
March 2001 Program Status Report
PACJET 2001 Poster NSSL Briefing
PROGRAM DOCUMENT
PACJET and a Long-term Effort to Improve 0-24 h West Coast Forecasts
Overview Poster
RESEARCH PARTICIPANTS
NOAA Research
  ETL,   NSSL,   FSL,   AL,   CDC
National Weather Service Western Region
  Eureka,   Hanford,   Medford,   Monterey,   Oxnard,   Portland,   Reno,   Sacramento,   San Diego,   Seattle,   CNFRC
Office of Marine and Aviation Operations
  AOC
Naval Postgradute School
DRI CIASTA
CIRES
SUNY Stony Brook
National Centers for Environmental Prediction
  EMC,   HPC,   MPC
National Environmental Satellite, Data and Information Service
  CIMSS,   CIRA
OPERATIONAL FORECASTING
COMPONENTS
COMET Presentation
West Coast RUC Aircraft Obs via AWIPS
GWINDEX Poster
Applications Development
RESEARCH COMPONENTS
Modeling Research Components
RELATED EXPERIMENTS
Winter Storm Reconnaissance (Central Pac.)
CRPAQS (CA Air Quality)
IMPROVE (Microphysics)
THORPEX (Synoptic Targeting)
OBSERVING SYSTEMS
AEROSONDE
NOAA P-3
Wind Profiler Network
Satellite Products
NOAA S-band Radar
CONTACTS
Program
Media Contacts
Webmaster
PLANNING WORKSHOPS
2001 - Monterey, CA
July 13-14 2000 (Boulder, CO)
July Workshop Agenda
September 1999 - Monterey, CA
1999 Planning Workshop Figures
June 1998 - CALJET

Poster announcing a West Coast Precipitation COMET training course for river forecasters.
OAR Hot Items Bulletin

Orographic precipitation enhancement

  • rain rate is most strongly controlled by upslope winds at 1 km altitude, especially in a LLJ
  • blocking increases rain upstream of terrain
  • precipitation efficiency is 50% higher when a LLJ is present than when it is not:
    0.9 (mm h-1) (m s-1)-1 with a LLJ vs. 0.6 (mm h-1) (m s-1)-1 without a LLJ

Warm rain

  • rain rates in west coast storms can exceed 20 mm/h in conditions without a bright band
  • for cases with the same rain rate, reflectivities were roughly 8 dBZ lower in warm rain cases
  • 35% of rain in the 1997/98 winter occurred without a bright band, < 5% did in 2000/01
  • Significant rain can occur without a bright band, but not every year.

Bright-band detection

  • an automated algorithm using wind profiler observations was developed and is being tested
  • real time output are on the web and deduced altitudes are a better estimate of snow level than is the 0C level
  • rapid 2000 ft increases in melting level are often observed and can triple runoff in CA watersheds

Sea-surface fluxes and coastal rainfall

  • high surface winds combined with anomalously warm coast SSTs can increase coastal rain
  • observations in a flooding event showed a 27% increase in CAPE due to these fluxes
  • this flooding event was capped off by convective rain rates that reached 80 mm/h

Flooding in adjacent watersheds

  • wind direction in the warm sector of a major storm determined the location of a rainshadow
  • the rain shadow resided partially over one watershed but not over an adjacent watershed
  • small ( 10) wind direction variations can strongly affect winter flooding in complex terrain

Narrow moisture plumes

  • P-3 soundings offshore with roughly 80 km spacing documented a narrow moisture plume
  • the core of the plume was roughly 100 km wide, with IWV > 3.0 cm
  • the core values were 40% greater than the maximum IWV derived from GOES due to clouds
  • Key aspects of a narrow moist plume responsible for a 4" rain event were missed by GOES and numerical models.

NOAA | ETL | CALJET | PACJET 2001 | PACJET 2002
NOAA ENVIRONMENTAL TECHNOLOGY LABORATORY
325 Broadway R/ETL
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Updated: January 22, 2001
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