65th IHC Booklet/Program (pdf - 4.9MB) - Office of the Federal ...

Advanced Applications of Monte Carlo Wind Probability Model:
A Year 2 Joint Hurricane Testbed Project Update
Mark DeMaria 1 , Robert DeMaria 2 , Andrea Schumacher 2 , Daniel Brown 3 ,
Michael Brennan 3 , Richard Knabb 4 , Pablo Santos 5 , David Sharp 6 , John Knaff 1 and Stan Kidder 2
(Mark.DeMaria@noaa.gov)
1 NOAA/NESDIS; 2 CIRA, Colorado State University; 3 NOAA/NCEP/NHC;
4 The Weather Channel; 5 NOAA/National Weather Service, Miami, FL;
6 NOAA/National Weather Service, Melbourne, FL
Under previous JHT support, a program for estimating the probability of occurrence of 34, 50,
and 64 kt winds was developed by NESDIS and CIRA. A Monte Carlo (MC) method was
utilized to combine the uncertainty in the track, intensity, and wind structure forecasts for
tropical cyclones. The MC probability program was transitioned to NHC operations in 2006.
In the current project, four new applications of the MC model were proposed including (1)
Landfall timing and intensity distributions; (2) Methods for using the MC model to enhance
WFO local products; (3) Probabilities integrated over coastal segments; (4) Automated guidance
for issuing coastal watches and warnings. A prototype graphical user interface has been
developed for items (1), (3), and (4) above, and examples will be presented. A validation of the
MC model for a large sample of cases for coastal and inland points was completed to help define
probability thresholds needed for the WFO local application per item (2). Results from that study
were presented last year, and will be very briefly summarized.
Four refinements to the MC model code were also proposed. These include (1) A procedure to
adjust the model time step for fast moving and small storms; (2) Modification of the azimuthal
interpolation routine that occasionally leads to inconsistent probability values for 34, 50, and 64
kt winds; (3) Evaluation of the spatial interpolation method that sometimes results in
inconsistencies between the gridded and text probabilities; (4) Evaluation of the underlying wind
radii model utilized by the MC model. Results from items (1) and (4) were presented last year, so
the emphasis will be on results from (2) and (3).
DISCLAIMER: The views, opinions, and findings in this report are those of the authors and
should not be construed as an official NOAA and/or U.S. Government position, policy, or
decision.
Session 12 – Page 4