Current Watches/Warnings A Warning is in effect from east of Morgan City, Louisiana to the Mississippi-Alabama border, including metropolitan New Orleans, Lake Pontchartrain and Lake Maurepas A Watch is in effect from Intracoastal City to Morgan City, Louisiana A Warning is in effect from east of the Mississippi-Alabama border to the Alabama-Florida border; Morgan City to Sabine Pass, Texas A Watch is in effect from east of High Island, Texas to just west of Sabine Pass Current Details from the National Center (NHC) COORDINATES: 29.6 north, 90.7 west (previous location: 28.7 north, 89.2 west) LOCATION: near Houma, Louisiana MOVEMENT: northwest at 6 mph (9 kph) (previous movement: northwest at 8 mph (13 kph)) WINDS: 75 mph (120 kph) with gusts to 90 mph (150 kph) (previous sustained winds: 80 mph (130 kph)) RADIUS OF TROPICAL STORM-FORCE WINDS: 175 miles (280 kilometers) from the center of circulation RADIUS OF HURRICANE-FORCE WINDS: 45 miles (75 kilometers) from the center of circulation CENTRAL PRESSURE: 972 mb (28.70 inches of mercury) (previous pressure: 975 mb) SAFFIR-SIMPSON SCALE RANKING*: Category 1 1 st LANDFALL LOCATION: southern Haiti 1 st LANDFALL TIMEFRAME: approximately 2:00 AM Saturday morning Eastern Time (6:00 UTC Saturday) 1 st LANDFALL INTENSITY: 70 mph (110 kph) 2 nd LANDFALL LOCATION: Plaquemines Parish, Louisiana 2 nd LANDFALL TIMEFRAME: 6:45 PM CDT Tuesday (23:45 UTC) 2 nd LANDFALL INTENSITY: 80 mph (130 kph) Category 1 3 rd LANDFALL LOCATION: just west of Port Fourchon, Louisiana 3 rd LANDFALL TIMEFRAME: 2:15 AM CDT Wednesday (7:15 UTC) 3 rd LANDFALL INTENSITY: 80 mph (130 kph) Category 1 Latest Satellite Picture (Image by NOAA) Impact Forecasting Cat Alert: Isaac Position and Intensity Data as of 10:00 AM Central Time, August 29, 2012 1
Discussion Isaac, located near Houma, Louisiana, is currently tracking northwest at 6 mph (9 kph). Isaac is inland over southeastern Louisiana near Houma. The cyclone has maintained an impressive radar signature, which includes a ragged 45-mile (75-kilometer) diameter eye. Curved convective rainbands have increased in the eastern semicircle, and Doppler Radar velocities of near 90 mph (150 kph) over water support keeping Isaac as a minimal hurricane for this advisory. Similar Doppler velocities over land and over Lake Pontchartrain suggest wind gusts to near 90 mph (150 kph) could occur inland over southeastern Louisiana into this afternoon. However, by late this afternoon or evening, Isaac is forecast to weaken to a tropical storm and become a tropical depression by Thursday night. The initial motion estimate is towards the northwest. Isaac is expected to move slowly northwestward through a weakness in the ridge of high pressure for the next 24 hours, and then turn north-northwestward and northward around the western periphery of the ridge within the next 36 to 48 hours. By 72 hours, Isaac is forecast to become a post-tropical remnant low pressure system that should move northeastward to east-northeastward when it will be caught up in weak mid-latitude westerlies. There are currently no indications in any of the model guidance suggesting that Isaac will tap into any baroclinic energy sources that could result in extratropical strengthening over the central United States. The official NHC track forecast is similar to the previous advisory, and is just east of the model consensus. Since Isaac is forecast to move slowly over the next 24 to 36 hours, there will be a prolonged threat of flooding from heavy rains over the northern Gulf Coast area and the south-central United States. National Ocean Service tide gages indicate that storm surge heights of 6 to 8 feet are still occurring along portions of the coast of southeastern Louisiana and Mississippi. Given the long duration of onshore flow in these areas, water levels are expected to remain high through today. The combination of a storm surge and the tide will cause normally dry areas near the coast to be flooded by rising waters. The water could reach the following depths above ground if the peak surge occurs at the time of high tide: - Mississippi and southeastern Louisiana: 6 to 12 feet - Alabama: 3 to 6 feet - South-central Louisiana: 3 to 6 feet - Florida Panhandle and Apalachee Bay: 2 to 4 feet The deepest water will occur along the immediate coast in areas of onshore winds. Surge-related flooding depends on the relative timing of the surge and the tidal cycle, and can vary greatly over short distances. Near the coast, the surge will be accompanied by large and dangerous waves. surge values of near 8 feet have recently been reported at Shell Beach, Louisiana and Waveland, Mississippi. storm conditions will continue across the warning area today, and hurricane conditions will continue to affect portions of southeastern Louisiana and Mississippi in the Warning area into this afternoon. Winds affecting the upper floors of high-rise buildings will be significantly stronger than those near ground level. At about the 30 th story, winds would likely be one Saffir-Simpson category stronger than at the surface. Isaac is expected to produce total rainfall amounts of 7 to 14 inches with possible isolated maximum amounts of 20 inches over much of Louisiana, southern Mississippi and southwest Alabama through Friday morning. These rains could result in significant lowland flooding. Rains are expected to increase northward into Arkansas on Thursday, with amounts of 3 to 6 inches expected over southern Arkansas by Friday morning. Impact Forecasting Cat Alert: Isaac Position and Intensity Data as of 10:00 AM Central Time, August 29, 2012 2
Isolated tornadoes are possible along the central Gulf Coast region and parts of the Lower Mississippi River Valley through Thursday. Dangerous surf and rip current conditions will continue to affect the west coast of Florida and the northern Gulf Coast for the next day or so. National Center Forecast (Maximum sustained winds listed near times) Impact Forecasting Cat Alert: Isaac Position and Intensity Data as of 10:00 AM Central Time, August 29, 2012 3
National Center Wind Speed Probabilities -Force Wind Probabilities ( 40 mph (65 kph)) Impact Forecasting Cat Alert: Isaac Position and Intensity Data as of 10:00 AM Central Time, August 29, 2012 4
Wind Probabilities ( 60 mph (95 kph)) Impact Forecasting Cat Alert: Isaac Position and Intensity Data as of 10:00 AM Central Time, August 29, 2012 5
-Force Wind Probabilities ( 75 mph (120 kph)) Impact Forecasting Cat Alert: Isaac Position and Intensity Data as of 10:00 AM Central Time, August 29, 2012 6
Additional Information and Update Schedule Wind intensity forecasts and forecast track information can be found via the National Center at www.nhc.noaa.gov. NEXT CAT ALERT: This afternoon after 4:00 PM Central Time. Impact Forecasting Cat Alert: Isaac Position and Intensity Data as of 10:00 AM Central Time, August 29, 2012 7
* Intensity Classifications for Global Basins WIND SPEED KTS 1 MPH 1 KPH 1 30 35 55 NE Pacific, Atlantic National Center (NHC) NW Pacific Joint Warning Center (JTWC) BASINS AND MONITORING BUREAU NW Pacific Japan Meteorological Agency (JMA) SW Pacific Fiji Meteorological Service (FMS) Australia Bureau Of Meteorology (BOM) Low SW Indian Meteo-France (MF) North Indian India Meteorological Department (IMD) Deep 35 40 65 40 45 75 45 50 85 50 60 95 55 65 100 60 70 110 Cat. 1 Cat. 2 Cat. 1 Cat. 2 Moderate 65 75 120 70 80 130 75 85 140 80 90 150 Cat. 1 Cat. 3 Cat. 3 85 100 160 90 105 170 95 110 175 100 115 185 105 120 195 110 125 205 Cat. 2 Cat. 3 Major Cat. 4 Cat. 4 Intense Very 115 130 210 120 140 220 125 145 230 130 150 240 135 155 250 Cat. 4 Major 140 160 260 Cat. 5 Major >140 >160 >260 Super Cat. 5 Cat. 5 Very Intense Super Impact Forecasting Cat Alert: Isaac Position and Intensity Data as of 10:00 AM Central Time, August 29, 2012 8
About Impact Forecasting LLC: Impact Forecasting LLC is a catastrophe model development center of excellence within Aon Benfield whose seismologists, meteorologists, hydrologists, engineers, mathematicians, GIS experts, finance, risk management and insurance professionals analyze the financial implications of natural and man-made catastrophes around the world. Impact Forecasting s experts develop software tools and models that help clients understand underlying risks from hurricanes, tornadoes, earthquakes, floods, wildfires and terrorist attacks on property, casualty and crop insurers and reinsurers. Impact Forecasting is the only catastrophe model development firm integrated into a reinsurance intermediary. To find out more about Impact Forecasting LLC, visit www.impactforecasting.com. About Aon Benfield: As the industry leader in treaty, facultative and capital markets, Aon Benfield is redefining the role of the reinsurance intermediary and capital advisor. Through our unmatched talent and industry-leading proprietary tools and products, we help our clients to redefine themselves and their success. Aon Benfield offers unbiased capital advice and customized access to more reinsurance and capital markets than anyone else. As a trusted advocate, we provide local reach to the world s markets, an unparalleled investment in innovative analytics, including catastrophe management, actuarial, and rating agency advisory, and the right professionals to advise clients in making the optimal capital choice for their business. With an international network of more than 4,000 professionals in 50 countries, our worldwide client base is able to access the broadest portfolio of integrated capital solutions and services. Learn more at aonbenfield.com. Cat Alerts use publicly available data from the internet and other sources. Impact Forecasting LLC summarizes this publicly available information for the convenience of those individuals who have contacted Impact Forecasting LLC and expressed an interest in natural catastrophes of various types. To find out more about Impact Forecasting or to sign up for the Cat Reports, visit Impact Forecasting s webpage at www.impactforecasting.com. Copyright by Impact Forecasting L.L.C. No claim to original government works. The text and graphics of this publication are provided for informational purposes only. While Impact Forecasting LLC has tried to provide accurate and timely information, inadvertent technical inaccuracies and typographical errors may exist, and Impact Forecasting LLC does not warrant that the information is accurate, complete or current. The data presented at this site is intended to convey only general information on current natural perils and must not be used to make life-or-death decisions or decisions relating to the protection of property, as the data may not be accurate. Please listen to official information sources for current storm information. This data has no official status and should not be used for emergency response decision-making under any circumstances. Copyright by Aon plc. All rights reserved. No part of this document may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying, recording or otherwise. Impact Forecasting is a wholly owned subsidiary of Aon plc. Impact Forecasting Cat Alert: Isaac Position and Intensity Data as of 10:00 AM Central Time, August 29, 2012 9
Current Watches/Warnings watches and warnings are not available. Current Details from the Joint Warning Center (JTWC) COORDINATES: 31.1 north, 125.0 east (previous location: 25.9 north, 123.7 east) LOCATION: 830 kilometers (515 miles) south-southwest of Seoul, South Korea MOVEMENT: north-northeast at 23 kph (14 mph) (previous movement: north-northeast at 26 kph (16 mph)) WINDS: 95 kph (60 mph) with gusts to 120 kph (75 mph) (previous sustained winds: 95 kph (60 mph)) RADIUS OF TROPICAL STORM-FORCE WINDS: 150 kilometers (90 miles) from the center of circulation SAFFIR-SIMPSON SCALE RANKING*: 1 st LANDFALL LOCATION: Pingtung County, Taiwan 1 st LANDFALL TIMEFRAME: 5:00 AM Friday morning local time (21:00 UTC Thursday) 1 st LANDFALL INTENSITY: 205 kph (125 mph) Category 3 2 nd LANDFALL LOCATION: southwestern South Korea 2 nd LANDFALL TIMEFRAME: Wednesday evening Central Time 24-HOUR SIGNIFICANT INSURED LOSS POTENTIAL: Latest Satellite Picture (Image by the University of Wisconsin CIMSS) None Low Med High Impact Forecasting Cat Alert: Tembin Position and Intensity Data as of 10:00 AM Central Time, August 29, 2012 1
Discussion Tembin, located approximately 830 kilometers (515 miles) south-southwest of Seoul, South Korea, is currently tracking north-northeast at 23 kph (14 mph). Satellite imagery shows flaring central convection which is now contained north of the low level circulation center. The current intensity is maintained at 60 mph (95 kph) based on the latest Dvorak intensity estimates. Upper level analysis indicates Tembin continues to track increasingly northward around a ridge of high pressure and ahead of an advancing trough as vertical wind shear continues to increase. Water vapor imagery shows that southerly outflow has ceased due to the noted trough over eastern China. Tembin is forecast to track northeastward through the next 12 hours under the influence of the noted ridge and trough, though a more eastward trajectory is anticipated after this time due to the ridge shifting in response to remnants of Bolaven (currently located north of the ridge). The tropical storm will begin to weaken in the next 12 hours or so as it approaches landfall over the southwestern tip of the Korean Peninsula. Wind shear will continue to increase along with much cooler sea surface temperatures. The combination of the previously mentioned environmental factors coupled with the advection of the continental polar air mass will initiate an extratropical transition during this time. Postlandfall, the system will deteriorate due to frictional effects and the extratropical transition will be complete within 36 hours as the system exits the Korean Peninsula and into the Sea of Japan. Joint Warning Center Forecast Impact Forecasting Cat Alert: Tembin Position and Intensity Data as of 10:00 AM Central Time, August 29, 2012 2
Additional Information and Update Schedule Wind intensity forecasts and forecast track information can be found via the Joint Warning Center at https://metocph.nmci.navy.mil/jtwc.php. NEXT CAT ALERT: Since extratropical transition is about to occur, this is the final Cat Alert. Impact Forecasting Cat Alert: Tembin Position and Intensity Data as of 10:00 AM Central Time, August 29, 2012 3
* Intensity Classifications for Global Basins WIND SPEED KTS 1 MPH 1 KPH 1 30 35 55 NE Pacific, Atlantic National Center (NHC) NW Pacific Joint Warning Center (JTWC) BASINS AND MONITORING BUREAU NW Pacific Japan Meteorological Agency (JMA) SW Pacific Fiji Meteorological Service (FMS) Australia Bureau Of Meteorology (BOM) Low SW Indian Meteo-France (MF) North Indian India Meteorological Department (IMD) Deep 35 40 65 40 45 75 45 50 85 50 60 95 55 65 100 60 70 110 Cat. 1 Cat. 2 Cat. 1 Cat. 2 Moderate 65 75 120 70 80 130 75 85 140 80 90 150 Cat. 1 Cat. 3 Cat. 3 85 100 160 90 105 170 95 110 175 100 115 185 105 120 195 110 125 205 Cat. 2 Cat. 3 Major Cat. 4 Cat. 4 Intense Very 115 130 210 120 140 220 125 145 230 130 150 240 135 155 250 Cat. 4 Major 140 160 260 Cat. 5 Major >140 >160 >260 Super Cat. 5 Cat. 5 Very Intense Super Impact Forecasting Cat Alert: Tembin Position and Intensity Data as of 10:00 AM Central Time, August 29, 2012 4
About Impact Forecasting LLC: Impact Forecasting LLC is a catastrophe model development center of excellence within Aon Benfield whose seismologists, meteorologists, hydrologists, engineers, mathematicians, GIS experts, finance, risk management and insurance professionals analyze the financial implications of natural and man-made catastrophes around the world. Impact Forecasting s experts develop software tools and models that help clients understand underlying risks from hurricanes, tornadoes, earthquakes, floods, wildfires and terrorist attacks on property, casualty and crop insurers and reinsurers. Impact Forecasting is the only catastrophe model development firm integrated into a reinsurance intermediary. To find out more about Impact Forecasting LLC, visit www.impactforecasting.com. About Aon Benfield: As the industry leader in treaty, facultative and capital markets, Aon Benfield is redefining the role of the reinsurance intermediary and capital advisor. Through our unmatched talent and industry-leading proprietary tools and products, we help our clients to redefine themselves and their success. Aon Benfield offers unbiased capital advice and customized access to more reinsurance and capital markets than anyone else. As a trusted advocate, we provide local reach to the world s markets, an unparalleled investment in innovative analytics, including catastrophe management, actuarial, and rating agency advisory, and the right professionals to advise clients in making the optimal capital choice for their business. With an international network of more than 4,000 professionals in 50 countries, our worldwide client base is able to access the broadest portfolio of integrated capital solutions and services. Learn more at aonbenfield.com. Cat Alerts use publicly available data from the internet and other sources. Impact Forecasting LLC summarizes this publicly available information for the convenience of those individuals who have contacted Impact Forecasting LLC and expressed an interest in natural catastrophes of various types. To find out more about Impact Forecasting or to sign up for the Cat Reports, visit Impact Forecasting s webpage at www.impactforecasting.com. Copyright by Impact Forecasting L.L.C. No claim to original government works. The text and graphics of this publication are provided for informational purposes only. While Impact Forecasting LLC has tried to provide accurate and timely information, inadvertent technical inaccuracies and typographical errors may exist, and Impact Forecasting LLC does not warrant that the information is accurate, complete or current. The data presented at this site is intended to convey only general information on current natural perils and must not be used to make life-or-death decisions or decisions relating to the protection of property, as the data may not be accurate. Please listen to official information sources for current storm information. This data has no official status and should not be used for emergency response decision-making under any circumstances. Copyright by Aon plc. All rights reserved. No part of this document may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying, recording or otherwise. Impact Forecasting is a wholly owned subsidiary of Aon plc. Impact Forecasting Cat Alert: Tembin Position and Intensity Data as of 10:00 AM Central Time, August 29, 2012 5