Extended Abstract (196K)P5.19
Towards greater understanding of inter-seasonal and multi-decadal variability and extremes of extratropical storminess in Florida
Bartlett C. Hagemeyer, NOAA/NWS, Melbourne, FL; and J. R. Almeida
Hagemeyer (2000) and Hagemeyer and Almeida (2002, 2003, and 2004) developed a dry season climatology (November 01-April 30) of strong extra-tropical (ET) cyclones (or storms) affecting Florida, and a forecast methodology to predict dry season “storminess” or the accumulated passage of ET cyclones in a dry season from the ENSO signal. The authors began publishing their experimental forecasts on the World Wide Web (WWW) in May 2001 for the 2001-02 dry season. Their storminess forecasts have proven reliable when the ENSO signal is dominant as during El Nino (above normal storms) or La Nina (below normal storms) conditions. However forecasting storminess during neutral conditions when other teleconnections such as the PNA, NAO, AO, and MJO may play a dominant role remains problematic.
The authors have recently expanded the storminess climatology to include the period from the 1948-49 to the 2002-03 dry seasons (53 seasons) and stratified the storms with regard to storm track (northern storm track, southern storm track, and Gulf of Mexico storm track). They also identified a special population of the Gulf of Mexico storms that they called “Florida Cyclones”. These storms developed in the Gulf of México in association with strong jet maxima, deepened significantly and moved right over portions of Florida. These relatively rare storms have the greatest potential for loss of life and property damage. The March 1993 “Superstorm” being perhaps the archetype “Florida Cyclone”. The storminess climatology revealed that seven of the top ten strongest ET cyclones (as measured by MSLP) from 1948 -2003 occurred during the 16 year period from 1982 – 1997 while the other 3 top ten storms occurred during the 33 year period from 1948 to 1981.
During the evolution of their research the authors realized that in addition to use in the development of a seasonal forecast, much information applicable to education, preparedness, and mitigation could be mined from the storminess climatology. Indeed, in order to facilitate the understanding and use of the seasonal forecasts there was a definite need to provide more accessible information to assist potential users of the forecasts in understanding forecast uncertainty and the limits of predictability, and factors controlling storminess variability and the range of climatic extremes that have occurred in the past to use as a guide to what to plan for in the future. The authors are developing graphics and conceptual models to help layman and non-scientist constituents understand the interplay of the major teleconnections that are responsible for much of the variability and extremes in storminess or lack of storminess (i.e. drought) in Florida. Examples of these products will be displayed on the poster at the conference and posted on our WWW experimental seasonal forecast page.
Supplementary URL: http://www.srh.noaa.gov/mlb/enso/mlbnino.html
Poster Session 5, Poster Session: Seasonal to Interannual Variability
Thursday, 13 January 2005, 9:45 AM-11:00 AM
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