Saturday, September 4, 2004


Here is a close-up radar loop from intellicast and a satellite loop from NOAA. Please also check for graphics that explain different aspects of the storm's impact.

For an hourly glimpse of what is happening on the ground in coastal Florida, follow this blogsite created by a stormchaser who is in the Melbourne area and reporting on current conditions, complete with pictures. A recent post to this site today includes details from a conference call with the National Hurricane Center.

You can also follow local news media reports, and check the latest webcams from the Orlando-Melbourne area, as well as surfcams throughout the Florida coast. I will continue adding special features as time and electrical power in FLA permit.

The path will be Fort Pierce-Melbourne to Orlando-Lakeland to Wildwood-Tampa over the next 24 hours. "The path" means those locations will be the boundary of the path of the eye, which will be 30 or more miles in diameter. Although the winds have lessened somewhat, the wind field has expanded which means that almost the entire state will experience tropical storm force winds (40-74 mph) and at least 1/4 to 1/3 of the state will have a very long duration of hurricane force winds. I am concerned that some residents will take the weakening as a sign to let their guard down. Charley proved that storms can change rapidly in a short period of time.

I cannot emphasize enough how catastrophic of a situation this is for Florida residents. Ignore the fact winds have down to 105 mph... for the area of wind coverage has INCREASED to over 100 miles in diameter. And usually hurricanes "blow on through" as did Gaston, Charley, Isabel, Floyd and on down the line of many past storms. As of 8am Sat, it was moving at barely 6 mph, but for hurricanes, especially one with winds of 100 mph+ that is stalled for all practical purposes. Recent radar imagery indicate the storm is trying to re-organize and create an inner eyewall, a process known as an "eyewall replacement cycle" that takes place when the outer eyewall expands outward, but the inner pressure draws up more moisture from the water to develop that second wall.

However, don't just focus on the exact center, the northern outflow contains the bulk of the moisture and winds. This eye is currently 70 nautical miles in diameter. Areas from Cape Canaveral all the way to probably Savannah and inland all the way to the gulf will get strong winds and incredibly heavy rain. I think average rainfall estimates will range from 12 to 24 inches. Some areas might get 20 inches in the first 24 hours.

The storm surge will be the worst we have seen in recent memory. Hundreds of thousands of structures along the coast will be battered to pieces by a surge of 1o feet, and due to the storm's slow movement, that water will be continually pushed inland for dozens of miles. I think this will catch many people off guard who thought that surge is only confined to the immediate coast.

Those who stayed behind should not be tempted to think it is over when the eye passes. Because the eye is so large, and the storm is moving so slow, many people will go outside and start cleaning up, or taking video. If they venture too far from home, they will be caught by the backside of the storm and not be able to get back. And it will taken 12 or more hours to go from the coast to Orlando, which means the eye may be over large areas of land for many hours.

Later today, I will conduct an analysis of the inland effects once this storm reaches the Tennessee Valley and Mid-Atlantic. It could be another "Agnes" type situation if the storm continues it's slow movement into the Appalachians.

Assuming the path described above, these are my projected observable effects following the line from Melbourne to Orlando to Ocala from Saturday early morning to Sunday night.


6 AM - Winds have picked up noticeably from the northeast and reached tropical storm force by daybreak. Gusts to 50 mph will be common. Showers will be widespread and locally torrential in heavier rain bands.

9 AM - Rain bands become heavier and more frequent as winds increase. Power outages begin.
Loose debris becomes airborne and impacts nearby structures. Gusts above tropical storm force are common on the

12 PM- Solid bands of rain spiral in from the northeast to southwest, dropping an inch or more in each band. Sustained northeast and east winds continue to increase to 60-70 mph.

3 PM - Winds increase to hurricane force. Rain becomes torrential as the outer eyewall bands cross the coast. Widespread debris becomes airborne and will puncture unprotected windows.

6 PM - Tornadoes begin to touch down through the 100 mile area of landfall. Sustained winds are above hurricane force, possibly 80-100 mph. Rainfall becomes more intense and roofs experiencing shingle damage will begin to leak profusely.

9 PM - The edge of sustained hurricane winds reaches the coast and moves inland, tropical downpours will be accompanied by sustained southeast winds of 75 to 90 mph with gusts to 100 mph or more. A storm surge of 5-10 feet rushes onshore and inland several miles, destroying most structures smaller than three stories. The center of the storm moves ashore late in the evening.


12 AM - Assuming the westward motion is roughly 5 mph, the area of hurricane force winds will extend from on Daytona Beach on the northside to West Palm Beach on the southside. Tropical storm force winds will be felt all the way from Fort Lauderdale northward to Jacksonville and westward out into the Gulf of Mexico. Moving at only 5 mph, it will take 10 hours to travel just 50 miles.

3 AM - The storm's eye is approaching Orlando from the southeast. Winds throughout Osceola, Lake and Orange counties will reach their maximum at 90 mph. Heavy rains will have saturated grounds to the point that winds will topple and uproot most large trees. Small streams and lakes will overflow due to the winds pushing them out of their banks. The strain on most roofs from constant wind battering will lead to roof and window failure.

6 AM - The large eye passes just south of the Orlando area.

9 AM - Winds in central Florida will drop below hurricane force, but gusts to 60-75 will remain for hours. The eye has passed to the northwest moving towards Ocala and Gainsville. The sustained tropical storm force winds of 40-60 mph remain in place. Rainfall continues to be torrential, and totals at this point have reached or exceeded 15 inches.

3 PM - Winds gradually decrease to minimal tropical storm force, and are now blowing from the south. Rain becomes more intermittent, but heavier squalls will continue bringing brief downpours and wind gusts.

6 PM - Winds shift to the southwest and then west as the bulk of the storm moves to northern Florida. Rainfall in Ocala, Gainsville and Tallahassee continues to be torrential as the core of the storm moves in their direction.

9 PM - winds finally decrease below tropical storm force, but still gust to 30-40 mph for the next several hours. Rain has stopped except for an occasional thunderstorm.

In conclusion, we all hope that none of this comes true and Frances continues to weaken and go out to sea.


For starters, take a look at the NHC projected track for Ivan over the next 5 days. The NHC forecast discussion is reveals that some computer models indicate we'll have another Category 4 or 5 storm to deal with approaching the US mainland a week from today. This I'll have details about that later today in the next update Saturday afternoon.

No comments: