Tropical Cyclone Wind Speed Probabilities

2008 Test With the GPCE Version of the MC Model

MC Model Versions

To evaluate the GPCE version of the MC probability model, a subset of the Atlantic cases from the 2008 season were re-run. These cases were run with the operational MC Model and the experimental version where the track error distributions are a function of the GPCE estimate.

Case Selection

For the GPCE evaluation, forecasts where the initial position was within 1,000 km from the U.S. coastline were chosen. The sample includes 167 cases, summarized below.

ATCF No. Storm Name #Cases First Case Last Case
AL02 Bertha 5 08071512 08071612
AL03 Cristobal 16 08071900 08072218
AL04 Dolly 16 08072012 08072406
AL05 Edouard 8 08080312 08080506
AL06 Fay 28 08081618 08082312
AL07 Gustav 21 08082718 08090118
AL08 Hanna 24 08083118 08090618
AL09 Ike 25 08090712 08091318
AL11 Kyle 6 08092706 08092812
AL13 Marco 7 08100600 08100712
AL17 Paloma 11 08110700 08110912

Evaluation Methods

The GPCE model will be evaluated by two methods. First, the 34, 50 and 64 kt wind probabilities for each case will be generated with the operational and GPCE models on a 0.2 deg. grid surrounding the forecast tracks. The 0-120hr cumulative probabilities for the operational and GPCE versions are shown below in the model results section. Difference plots will be added as well.

Second, the probabilities will be generated at the U.S., Caribbean and South and Central American breakpoints from the NHC web site. All points except the west coast of Mexico and Hawaii will be included. Hawaii and the Mexican west coast are excluded to reduce the number of verification points with very small or zero probabilities, the verification will be performed at the remaining breakpoints.

Model Results

Click on links below to see the comparison of the operational and GPCE MC Model 0-120 hr cumulative probabilties for each case. For each run the GPCE values are listed at the top of the page, for each 12 hr. period. The track error tercile (L=low, M=medium, H=high, X=missing/unused) used at each time period is also shown. The basin-wide distributions were used if the GPCE value was missing.

Bertha (Operational: 100%) (GPCE: 100%) (Table: 100%)

08071512 08071518
08071600 08071606 08071612

Cristobal (Operational: 100%) (GPCE: 100%) (Table: 100%)

08071900 08071906 08071912 08071918
08072000 08072006 08072012 08072018
08072100 08072106 08072112 08072118
08072200 08072206 08072212 08072218

Dolly (Operational: 100%) (GPCE: 100%) (Table: 100%)

08072012 08072018
08072100 08072106 08072112 08072118
08072200 08072206 08072212 08072218
08072300 08072306 08072312 08072318
08072400 08072406

Edouard (Operational: 100%) (GPCE: 100%) (Table: 100%)

08080312 08080318
08080400 08080406 08080412 08080418
08080500 08080506

Fay (Operational: 100%) (GPCE: 100%) (Table: 100%)

08081618
08081700 08081706 08081712 08081718
08081800 08081806 08081812 08081818
08081800 08081806 08081812 08081918
08082000 08082006 08082012 08082018
08082106 08082112 08082118 08082200
08082206 08082212 08082218 08082300
08082306 08082312

Gustav (Operational: 100%) (GPCE: 100%) (Table: 100%)

08082718
08082800 08082806 08082812 08082818
08082900 08082906 08082912 08082918
08083000 08083006 08083012 08083018
08083100 08083106 08083112 08083118
08090100 08090106 08090112 08090118

Hanna (Operational: 100%) (GPCE: 100%) (Table: 100%)

08083118
08090100 08090106 08090112 08090118
08090200 08090206 08090212 08090218
08090300 08090306 08090312 08090318
08090400 08090406 08090412 08090418
08090500 08090506 08090512 08090518
08090600 08090606 08090612 08090618

Ike (Operational: 100%) (GPCE: 100%) (Table: 100%)

08090712
08090718 08090800 08090806 08090812
08090818 08090900 08090906 08090912
08090918 08091000 08091006 08091012
08091018 08091100 08091106 08091112
08091118 08091200 08091206 08091212
08091218 08091300 08091306 08091312
08091318

Kyle (Operational: 100%) (GPCE: 100%) (Table: 100%)

08092706 08072712 08072718
08072800 08072806 08072812

Marco (Operational: 100%) (GPCE: 100%) (Table: 100%)

08100600 08100606 08100612 08100618
08100700 08100706 08100712

Paloma (Operational: 100%) (GPCE: 100%) (Table: 100%)

08110700 08110706 08110712 08110718
08110800 08110806 08110812 08110818
08110900 08110906 08110912

©2009 RAMMB | Page Last Updated: February 13th, 2009