Skip to Navigation Skip to content

Regional and Mesoscale Meteorology Branch

Search the RAMMB website

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#CasesFirst CaseLast Case
AL02Bertha50807151208071612
AL03Cristobal160807190008072218
AL04Dolly160807201208072406
AL05Edouard80808031208080506
AL06Fay280808161808082312
AL07Gustav210808271808090118
AL08Hanna240808311808090618
AL09Ike250809071208091318
AL11Kyle60809270608092812
AL13Marco70810060008100712
AL17Paloma110811070008110912

 

 

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%)

  0807151208071518
080716000807160608071612

 

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

08071900080719060807191208071918
08072000080720060807201208072018
08072100080721060807211208072118
08072200080722060807221208072218

 

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

  0807201208072018
08072100080721060807211208072118
08072200080722060807221208072218
08072300080723060807231208072318
0807240008072406

 

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

  0808031208080318
08080400080804060808041208080418
0808050008080506

 

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

   08081618
08081700080817060808171208081718
08081800080818060808181208081818
08081800080818060808181208081918
08082000080820060808201208082018
08082106080821120808211808082200
08082206080822120808221808082300
0808230608082312

 

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

   08082718
08082800080828060808281208082818
08082900080829060808291208082918
08083000080830060808301208083018
08083100080831060808311208083118
08090100080901060809011208090118

 

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

   08083118
08090100080901060809011208090118
08090200080902060809021208090218
08090300080903060809031208090318
08090400080904060809041208090418
08090500080905060809051208090518
08090600080906060809061208090618

 

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

   08090712
08090718080908000809080608090812
08090818080909000809090608090912
08090918080910000809100608091012
08091018080911000809110608091112
08091118080912000809120608091212
08091218080913000809130608091312
08091318   

 

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

 080927060807271208072718
080728000807280608072812 

 

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

08100600081006060810061208100618
081007000810070608100712 

 

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

08110700081107060811071208110718
08110800081108060811081208110818
081109000811090608110912