Extended Abstract (1.7M)2.5
An observational and high-resolution model analysis of gale wind events in the Gulf of California
Ariel E. Cohen, NOAA/NWSFO, Jackson, MS; and J. P. Cangialosi
The National Oceanic and Atmospheric Administration's (NOAA's) National Hurricane Center (NHC) in Miami, FL issues High Seas Forecasts to portions of the eastern Pacific Ocean, including the Gulf of California. These forecasts include 10-meter winds and significant wave heights with a threshold of winds of greater than 20 kt or significant wave heights of at least 8 ft. The Gulf of California is a critical area for the recreation and fishing industries. Winds in the Gulf of California are highly modulated by nearby terrain variations. This provides a unique forecast challenge, especially in the absence of regular surface observations. In October and November 2008, the NOAA Research Vessel David Starr Jordan was stationed in the northern Gulf of California and occasionally reported gale force winds, which operational models regularly missed. A ship log of these events provided the basis for determining mean and anomaly fields for a handful of meteorological variables, from which we present a conceptual model for the synoptic scale environment supporting these events. An index based on the MSLP difference between Ely, NV and Yuma, AZ was developed to measure the potential for gales, which is found to be statistically significant in discriminating between gale and non-gale events. Doubly-nested MM5 runs centered on the Gulf of California appear to resolve these gales, lending credence toward the need for high-resolution modeling in areas of highly-variable terrain. Relatively small errors are found in MM5 output using QuikSCAT data as verification.
Session 2, Field experiments: observational results from past field experiments; potential relevance of the field observations to operational prediction
Monday, 18 January 2010, 4:00 PM-5:15 PM, B207
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