Tropical Weather Briefing August 26, PM CDT National Weather Service Weather Forecast Office Slidell, LA August 26, PM CDT National Weather Service Weather Forecast Office Slidell, LA

Current Satellite

Tropical Storm Isaac

Tropical Storm Isaac Track Guidance

Tropical Storm Isaac Intensity Forecast

Tropical Storm Isaac TS Wind Probability Forecast

Tropical Storm Isaac Hurricane Wind Probability Forecast

Tropical Storm Isaac Wind Forecast

Tide Levels Currently in Spring Tide MS Coast: Tide levels increasing to 8 to 12 feet above normal during high tide cycles through Wednesday. SE LA Coast: Tide levels increasing to 5 to 7 feet above normal within Lake Pontchartrain, 5 to 9 feet above normal west of the MS River and 7 to 11 feet above normal east of the MS River through Wednesday high tide cycle. Currently in Spring Tide MS Coast: Tide levels increasing to 8 to 12 feet above normal during high tide cycles through Wednesday. SE LA Coast: Tide levels increasing to 5 to 7 feet above normal within Lake Pontchartrain, 5 to 9 feet above normal west of the MS River and 7 to 11 feet above normal east of the MS River through Wednesday high tide cycle.

Tide Levels

Rainfall through Wed.

Summary Onset of TS winds: late Monday night/early Tuesday morning Tropical Storm wind duration: 24 hours for most locations with a few locations up to 36 hours Hurricane force wind duration: 8 to 10 hours in areas within direct path Tropical storm force wind probabilities range from 80-90% for the MS coast and 70-80% for SE LA north and south of Lake Pontchartrain and 50-70% across River Parishes and areas around BTR. Rainfall: 12 to 16 inches. Highest threat along and east of track. Tornadoes: Threat Tuesday through Wednesday Onset of TS winds: late Monday night/early Tuesday morning Tropical Storm wind duration: 24 hours for most locations with a few locations up to 36 hours Hurricane force wind duration: 8 to 10 hours in areas within direct path Tropical storm force wind probabilities range from 80-90% for the MS coast and 70-80% for SE LA north and south of Lake Pontchartrain and 50-70% across River Parishes and areas around BTR. Rainfall: 12 to 16 inches. Highest threat along and east of track. Tornadoes: Threat Tuesday through Wednesday

Summary HURRICANE WARNING is now in effect in the previous watch area. This includes the New Orleans metro area and the MS coast. TROPICAL STORM WARNING is now in effect for SW MS and E-central LA including the Baton Rouge metro area. Tropical Storm Isaac current forecast track has adjusted more westward of previous advisory – now closer to Bay-Waveland area early Wed morning. Forecast intensity still calls for a strong Category 2 hurricane at its U.S. landfall. Tropical storm force wind probabilities range from 80-90% for the MS coast and 60 to 85% for SE LA north and south of Lake Pontchartrain. Hurricane force wind probabilities are now 15-20% for MS coast and SE LA north and south of Tidal Lakes…and 5-10% over the River Parish and BTR area. HURRICANE WARNING is now in effect in the previous watch area. This includes the New Orleans metro area and the MS coast. TROPICAL STORM WARNING is now in effect for SW MS and E-central LA including the Baton Rouge metro area. Tropical Storm Isaac current forecast track has adjusted more westward of previous advisory – now closer to Bay-Waveland area early Wed morning. Forecast intensity still calls for a strong Category 2 hurricane at its U.S. landfall. Tropical storm force wind probabilities range from 80-90% for the MS coast and 60 to 85% for SE LA north and south of Lake Pontchartrain. Hurricane force wind probabilities are now 15-20% for MS coast and SE LA north and south of Tidal Lakes…and 5-10% over the River Parish and BTR area.

Summary Isaac has strengthened slightly and thunderstorms has increased near the center. A large rain area to the north of center was expanding N and W. A larger part of the outlook area will be affected by this storm. Some of the model guidance continues to indicate a shift more to the west, which could mean adjustments to the track in the next few advisories. Isaac has strengthened slightly and thunderstorms has increased near the center. A large rain area to the north of center was expanding N and W. A larger part of the outlook area will be affected by this storm. Some of the model guidance continues to indicate a shift more to the west, which could mean adjustments to the track in the next few advisories.

Next Update s will come out after every advisory. Next webinar will be Monday 2 PM CDT. s will come out after every advisory. Next webinar will be Monday 2 PM CDT.

Contact Information Don’t hesitate to call or us with any questions (985) 649–0429, (985) –Extension 4 to speak to a forecaster NWS Chat –If you don’t use software(i.e. pidgin) please log into NWSCHAT live This helps bypass the third party security issues and runs in your web browser Follow us on Don’t hesitate to call or us with any questions (985) 649–0429, (985) –Extension 4 to speak to a forecaster NWS Chat –If you don’t use software(i.e. pidgin) please log into NWSCHAT live This helps bypass the third party security issues and runs in your web browser Follow us on