TROPICAL CYCLONE IMPACTS - DECISION SUPPORT
The Tropical Cyclone Impact Graphics project is a combined effort involving Eastern Region Headquarters, Southern Region Headquarters, Western Region Headquarters, National Weather Service Headquarters, and 25 coastal Weather Forecast Offices (WFOs). The images presented are a graphical representation of a WFOs Hurricane Local Statement (HLS).
Below is a listing of the WFOs providing Impact Graphics when tropical cyclone watches or warnings are in effect for their respective forecast areas.|
|Tropical Cyclone Impact Graphics|
Overview and Product Description
The Tropical Cyclone Impacts Graphics web site is an internet-based decision-support service consisting of at least four graphics: high wind, coastal flooding (e.g., surge), inland flooding (e.g., heavy rain), and tornadoes. During the 2011 Hurricane Season, the graphics will be generated and posted by the 25 coastal Weather Forecast Offices (WFOs) listed above whenever tropical cyclone watches and/or warnings are in effect for their area.
Per tropical cyclone hazard, each graphic is based on the most recent threat assessment as centered on a particular area of interest, and is presented in terms of potential impact while using associated descriptions unique to that area. The graphics responsibly take into account the forecast magnitude of the hazard, along with the associated forecast uncertainty. Depictions combine the expertise of the local WFO with those of the National Hurricane Center, the Storm Prediction Center, and the Hydrometeorological Prediction Center. The graphics are designed to distill an abundance of complex information into easy to understand colorized maps for decision-making purposes. They provide an "at-a-glance" summary of cumulative impacts that have the reasonable potential to occur. Consequently, the web site can be used as a coherent briefing tool. The valid period is for the duration of the event as the graphics do not convey specific timing. Updates will be provided at least every six hours, and will cease when watches and/or warnings are no longer in effect within the specified area.
While most participating WFOs will provide Tropical Cyclone Impact Graphics for each of the aforementioned hazards, some WFOs may provide additional graphics (e.g., marine, combined hazards bar charts, etc.) as project development continues.
Important Note: Given that tropical cyclone forecasts are subject to change with each successive issuance and that they also contain some measure of inherent error, the graphics DO NOT depict "expected impacts" (as might be worded within the textual Hurricane Local Statement). Rather, the graphics depict "potential impacts" which take into account the uncertainty of the forecast as well. This serves as a practical least-regret approach for including proportional margins of safety while delivering a more consistent message. Also, the impact descriptions for each color-filled area are generalized. Impacts realized at exact point locations may be greater or lesser in extent.Examples of Products
Each graphic may have up to six color indicators as follows: Gray | | representing "None" impact(s), Dodger Blue | | representing "Very Low" impact(s), Yellow | | representing "Low" impact(s), Orange | | representing "Moderate" impact(s), Red | | representing "High" impact(s), and Fuchsia | | representing "Extremely High" impact(s).
The example graphics below are provided for South Florida. The corresponding descriptions of graduated impact levels for each of the hazards can be found by viewing the Miami-South Florida web site. Again, impact level descriptions have been customized by the associated WFO and are unique to their area of responsibility.
Important Note: Each WFO produces a suite of graphics for their own area of responsibility. Therefore, only the counties and parishes within that office's area of responsibility will be colorized. The timeliness and availability of these experimental graphics are subject to local resources as committed beyond the provision of official products and services, and therefore cannot be guaranteed.
The National Weather Service asks for your comments on these graphics. In particular we would like to know other desired formats for the graphics. Please provide feedback through November 30, 2011.