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Hazard and damage potential maps produced by Willis are based on numerical modeling results from Kinetic Analysis Corporation.

Hurricane KatiaInformation from NHC Advisory 13, 5:00 AM EDT Thursday September 1, 2011Hurricane Katia has changed little in strength over the past several hours, but some strengthening is forecast during the next two days and Katia could become a major storm by the weekend.

Intensity Measures Position & Heading Landfall Forecast (NHC)

Max Sustained Wind Speed:

75 mph (category 1)

Position Relative to Land:

1065 miles E of the Leeward Islands Est. Time & Region: n/a

Min Central Pressure: 987 mb Coordinates: 15.2 N, 45.9 W

Trop. Storm ForceWinds (39+ mph):

125 miles from the center Bearing/Speed: W or 280 degrees at 20 mph Est. Max Sustained Wind

Speed: n/a

HURRICANE TRACKING ADVISORY

eVENT™

Forecast Summary• Within 48 hours, there is a 90% chance Katia will remain a hurricane (74+ mph winds), a 10% chance Katia will weaken to a tropical storm (39-

73 mph winds) and less than a 1% chance Katia will weaken to a tropical depression (winds below 39 mph) or dissipate.

• The windfield map – based on the GFDL 00:00 UTC forecast (below right) – shows that this model has forecast the storm’s peak winds at

category 4 hurricane strength (130-155 mph winds). The GFDL – one of many models used by NOAA – has been statistically identified as the

current “best performing” model for Tropical Storm Katia by Kinetic Analysis Corp. Forecast tracks for all current models (All Fcst Tracks) are

shown on the map (in pale gray) to illustrate the uncertainty in Katia’s forecast track.

Forecast Track for Hurricane Katia(National Hurricane Center)

Forecast Windfield & Rain Footprint for Hurricane Katia(Based on GFDL as of 00:00 UTC) from Kinetic Analysis Corp.

Havana

Caracas

Santo Domingo

Washington D.C.

San JuanSan JuanKingstonKingston Port-au-PrincePort-au-Prince

NassauNassau

CastriesCastries

WillemstadWillemstadPort of SpainPort of Spain

Fort-De-FranceFort-De-France

New YorkNew YorkDetroitDetroit BuffaloBuffaloTorontoToronto

PittsburghPittsburgh

USUS

CUCU

DODO

VEVE

CACA

COCOCRCR

NINI

Tropic of CancerTropic of Cancer

Bermuda

09-06

09-05

09-0409-03

09-0209-01

0 1,000 2,000500 Miles

weak TSstrong TSCat 1Cat 2Cat 3Cat 4Cat 5All Fcst Tracks

below 1 in1 - 3 in3 - 6 in6 - 9 in9 - 12 in12 - 24 inGFDL FcstTrackNHC FcstTrack

Ï!D TD

Ï!S TS

Ï!1 Cat1

Ï!2 Cat2

Ï!3 Cat3

Ï!4 Cat4

Ï!5 Cat5

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Roy Cloutier7760 France Avenue SouthMinneapolis, MN 55435roy.cloutier@willis.com+1 (952) 841-6652

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Warnings, Watches and New Tropical Cyclone PotentialThere are no coastal watches or warnings in effect.

NHC Estimates of New Atlantic Tropical Cyclone FormationThe map to the right illustrates the NHC’s estimate of tropical

cyclone formation potential over the next 48 hours in the Atlantic.

There is a 60% chance of tropical cyclones formation in the red

region in the Gulf of Mexico.

National Hurricane Center Tropical Cyclone Formation Estimates on September 1, 2011

Summary of Atlantic Hurricane Activity to DateTropical Storm Activity to DateKatia is the eleventh named storm and second hurricane of

the 2011 Atlantic Hurricane Season. Seven named storms,

three hurricanes and two major hurricanes, Danielle and

Earl, had occurred by this date last year. The next tropical

storm of 2011 will be named Lee.

For the years 1995-2010, the average dates of the first

named storm, first hurricane and first major hurricane are

Jul 1, Aug 6 and Aug 30, respectively. Sep 5 and Sep 29 are

the average dates of the seventh and eleventh named

storms.

Benchmarking the 2011 Atlantic Season to DateTropical Storms

Total Hurricanes

Cat 3-5 Hurricanes

2011 year to date (1/1/10 – 9/1/11) 11 2 12010 year to date (1/1/09 – 9/1/11) 7 3 21995-2010 season average 14.4 7.9 3.81950-2010 season average 10.5 6.2 2.72010 CSU season forecasts(Colorado State University at Aug 3)

16 9 5

2010 NOAA season forecasts(NOAAs Climate Prediction Center at Aug 4)

14-19 7-10 3-5

Risk Remaining in the 2011 Atlantic Hurricane SeasonAtlantic hurricane activity and major hurricane activity

(categories 3-5) both peak in September, as the graph to the

right illustrates. The average remaining percentage of days

with Atlantic hurricane activity at August 31 is 70.7% for all

hurricanes and 74.4% for major hurricanes.

Percentage of Days with Active Hurricanes since 1900

0%

12%

24%

36%

48%

60%

Jun Jul Aug Sep Oct Nov Dec

Ave

rage

Dai

ly R

isk

0%

20%

40%

60%

80%

100%

Ave

rage

Rem

aini

ng R

isk

All Hurricanes (1-5) Major Hurricanes (3-5)