TITLE

Wintertime Nonbrightband Rain in California and Oregon during CALJET and PACJET: Geographic, Interannual, and Synoptic Variability

AUTHOR(S)
Neiman, Paul J.; Wick, Gary A.; Ralph, F. Martin; Martner, Brooks E.; White, Allen B.; Kingsmill, David E.
PUB. DATE
May 2005
SOURCE
Monthly Weather Review;May2005, Vol. 133 Issue 5, p1199
SOURCE TYPE
Academic Journal
DOC. TYPE
Article
ABSTRACT
An objective algorithm presented in White et al. was applied to vertically pointing S-band (S-PROF) radar data recorded at four sites in northern California and western Oregon during four winters to assess the geographic, interannual, and synoptic variability of stratiform nonbrightband (NBB) rain in landfalling winter storms. NBB rain typically fell in a shallow layer residing beneath the melting level (<∼3.5 km MSL), whereas rainfall possessing a brightband (BB) was usually associated with deeper echoes (>∼6 km MSL). The shallow NBB echo tops often resided beneath the coverage of the operational Weather Surveillance Radar-1988 Doppler (WSR-88D) scanning radars yet were still capable of producing flooding rains. NBB rain contributed significantly to the total winter-season rainfall at each of the four geographically distinct sites (i.e., 18%–35% of the winter-season rain totals). In addition, the rainfall observed at the coastal mountain site near Cazadero, California (CZD), during each of four winters was composed of a significant percentage of NBB rain (18%–50%); substantial NBB rainfall occurred regardless of the phase of the El Niño–Southern Oscillation (which ranged from strong El Niño to moderate La Niña conditions). Clearly, NBB rain occurs more widely and commonly in California and Oregon than can be inferred from the single-winter, single-site study of White et al. Composite NCEP–NCAR reanalysis maps and Geostationary Operational Environment Satellite (GOES) cloud-top temperature data were examined to evaluate the synoptic conditions that characterize periods of NBB precipitation observed at CZD and how they differ from periods with bright bands. The composites indicate that both rain types were tied generally to landfalling polar-cold-frontal systems. However, synoptic conditions favoring BB rain exhibited notable distinctions from those characterizing NBB periods. This included key differences in the position of the composite 300-mb jet stream and underlying cold front with respect to CZD, as well as notable differences in the intensity of the 500-mb shortwave trough offshore of CZD. The suite of BB composites exhibited dynamically consistent synoptic-scale characteristics that yielded stronger and deeper ascent over CZD than for the typically shallower NBB rain, consistent with the GOES satellite composites that showed 20-K warmer (2.3-km shallower) cloud tops for NBB rain. Composite soundings for both rain types possessed low-level potential instability, but the NBB sounding was warmer and moister with stronger low-level upslope flow, thus implying that orographically forced rainfall is enhanced during NBB conditions.
ACCESSION #
17239749

 

Related Articles

  • Rain versus Snow in the Sierra Nevada, California: Comparing Doppler Profiling Radar and Surface Observations of Melting Level. Lundquist, Jessica D.; Neiman, Paul J.; Martner, Brooks; White, Allen B.; Gottas, Daniel J.; Ralph, F. Martin // Journal of Hydrometeorology;Apr2008, Vol. 9 Issue 2, p194 

    The maritime mountain ranges of western North America span a wide range of elevations and are extremely sensitive to flooding from warm winter storms, primarily because rain falls at higher elevations and over a much greater fraction of a basin’s contributing area than during a typical...

  • Snow-to-Liquid Ratio Variability and Prediction at a High-Elevation Site in Utah’s Wasatch Mountains. Alcott, Trevor I.; Steenburgh, W. James // Weather & Forecasting;Feb2010, Vol. 25 Issue 1, p323 

    Contemporary snowfall forecasting is a three-step process involving a quantitative precipitation forecast (QPF), determination of precipitation type, and application of a snow-to-liquid ratio (SLR). The final step is often performed using climatology or algorithms based primarily on temperature....

  • A Diagnosis of Tropospheric Effects upon Surface Precipitation Amount for a Sample of East Coast Snowstorms. Wichansky, Paul S.; Harnack, Robert H. // Weather & Forecasting;Jun2000, Vol. 15 Issue 3, p339 

    Upper-air variables have been correlated with near-simultaneous precipitation observations from 35 winter storms that produced heavy snowfall in the eastern coastal region of the United States. Standard radiosonde observations (raob's) were used to calculate upper-air variables at mandatory...

  • Reply. Penny, S. M.; Roe, G. H.; Battisti, D. S. // Journal of Climate;Oct2011, Vol. 24 Issue 19, p5192 

    Penny et al. recently showed that the midwinter suppression in storminess over the western and central Pacific Ocean is due to a reduction in the number and amplitude of 'seed' disturbances entering the Pacific storm track from midlatitude Asia. In this reply, the authors strengthen the...

  • The Dynamic and Thermodynamic Structures Associated with a Series of Heavy Precipitation Events over China during January 2008. Xiaohui Shi; Xiangde Xu; Chungu Lu // Weather & Forecasting;Aug2010, Vol. 25 Issue 4, p1124 

    In the winter of 2008, China experienced once-in-50-yr (or once in 100 yr for some regions) snow and ice storms. These storms brought huge socio economical impacts upon the Chinese people and government. Although the storms had been predicted, their severity and persistence were largely...

  • Raindrop Size Distributions and Rain Characteristics in California Coastal Rainfall for Periods with and without a Radar Bright Band. Martner, Brooks E.; Yuter, Sandra E.; White, Allen B.; Matrosov, Sergey Y.; Kingsmill, David E.; Ralph, F. Martin // Journal of Hydrometeorology;Jun2008, Vol. 9 Issue 3, p408 

    Recent studies using vertically pointing S-band profiling radars showed that coastal winter storms in California and Oregon frequently do not display a melting-layer radar bright band and inferred that these nonbrightband (NBB) periods are characterized by raindrop size spectra that differ...

  • Autumn and Winter Storms of the Eastern Canadian Arctic.  // CO2 Science;1/5/2011, Vol. 14 Issue 1, p5 

    The article reports on a study by G. Gascon et al which examined the characteristics and climatology of the 1955-2006 major cold-season precipitation events that occurred at Iqaluit, Nunavut based on analyses of hourly surface meteorological data from the public archives of Environment Canada....

  • Weather Conditions Associated With the Passage of Precipitation Type Transition Regions Over Eastern Newfoundland. Stewart, Ronald E.; Yiu, Dia T.; Chung, Kwok K.; Hudak, David R.; Lozowski, Edward P.; Oleskiw, Myron; Sheppard, Brian E.; Szeto, Kit K. // Atmosphere -- Ocean (Canadian Meteorological & Oceanographic Soc;Mar1995, Vol. 33 Issue 1, p25 

    The passage of a winter storm is accompanied by changes in many surface and near-surface parameters including temperature, humidity, wind, pressure, precipitation rate and type, cloud base height, visibility and accretion. These parameters were measured in association with the passage of...

  • One Hundred Inches in One Hundred Hours: Evolution of a Wasatch Mountain Winter Storm Cycle. Steenburgh, W. James // Weather & Forecasting;Dec2003, Vol. 18 Issue 6, p1018 

    Synoptic, orographic, and lake-effect precipitation processes during a major winter storm cycle over the Wasatch Mountains of northern Utah are examined using radar imagery, high-density surface data, and precipitation observations from Alta Ski Area [2600–3200 m above mean sea level...

Share

Read the Article

Courtesy of NEW JERSEY STATE LIBRARY

Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics