Tropical Depression Number 18 forms east of the southeastern Bahamas...
The system was classififed as a tropical depression as of 10 pm CDT. It is moving west northwest. It is expected to turn more to the west as a ridge of high pressure fills in to the north of the system. This will push the system toward the Florida Straits, Florida Keys or South Florida. Then it will move into the southeastern Gulf of Mexico. The high pressure ridge to the north will steer the hurricane westward across the Gulf.

Where it eventually will end up is uncertain. Earlier runs of the GFDL model carried it generally northwestward, but the afternoon run pushes it toward Mexico. The GFS has consistently taken it toward Mexico, south of the Texas coast, perhaps turning northward near the time of landfall and bringing rains northward into Texas.

The depression will be moving over very warm water and will be in a low shear environment. The only factor that could inhibit intensification will be dry air in the mid level. The GFDL still makes it a 140 mph hurricane in the Florida Straits and carries it near Key West Monday afternoon.

The official NHC track carries it near Key West late on Tuesday and into the Central Gulf by Thursday heading toward Mexico or the lower Texas Coast. The official forecast is much slower with intensification, only bringing the system to 90 mph by the end of the five days.


Tropical Depression Number 17 named Tropical Storm Philippe
The depression continued to look better organized on satellite pictures through the evening hours and was upraded to Tropical Storm Philippe at 10 p.m. The center of the storm was 485 miles east southeast of the Leewards and moving north northwest at 5 mph. It is expected to miss the islands as it continues in this same general direction. It should become a hurricane during the next 48 hours and is forecast to eventually have maximum sustained winds of 110 mph. It should pose no threat to the coast of the United States.


Tropical Storm Ophelia Losing Tropical Characteristics
The system will pass near Halifax, Nova Scotia tonight and near Newfoundland on Sunday. It will bring tropical storm force conditions to most of Nova Scotia and parts of Newfoundland. It is moving radpily northeast and will cross the cold waters of the North Atlantic, reaching the British Isles by midweek.

A historic event occurred on Friday. NOAA flew its first unmanned aircraft, or Aerosonde, into Hurricane Ophelia while it was moving along the East Coast of the United States. At 7:30 a.m. EDT, the Aerosonde was released from a ground based transport vehicle at NASA's Wallops Island Flight Facility in southeastern Virginia and lifted off for a ten hour successful mission.

Ophelia was perfect because currently flights must occur within flying range of the Wallops Island facility, which limits the range of use to about 1,500 total flight miles.

Researchers at NOAA’s Atlantic Oceanographic and Meteorological Laboratory (AOML) in Miami were overjoyed at the results of the flight. They hope that the missions will become routine events in the near future.

The information provided by Air Force Reserve and NOAA Hurricane Hunter aircraft is invaluable to forecasters. But the manned aircraft are unable to fly at low levels because of the turbulent conditions located there. Flying at altitudes as low as five hundred feet, the Aerosonde allows continuous real time sampling of the near-surface environment, which is increasingly believed to be critical in understanding intensification processes, needless to say how strong winds are at the surface.

During the historic flight, observations of temperature, pressure, humidity and wind speed were measured every half second and transmitted back to the National Hurricane Center and AOML by satellite. An infrared sensor also measured sea surface temperatures.

Currently, reconnaissance crews take flight level observations, from which surface winds must be estimated using a formula. Often, the estimates are not accurate. They also make visual observations of the sea state and estimate winds from those observations. The Aerosondes will allow for more accurate low level wind measurements.

The air-sea interface appears to be important in understanding intensification, because this is where energy is transferred from the ocean to the storm through evaporation. Data from low flyin Aerosondes could help forecasters to make better intensity change forecasts.

The Aerosondes have a flight level ceiling of 2500 feet when manned aircraft are in the area. The Aerosondes will be permitted to spiral all the way to 10,000 feet in the eye at the end of each mission for a special sounding if no aircraft are in the area.

The Aerosonde returned in pristine condition at 5:30 p.m. EDT Friday to its launch site at the NASA Wallops Island Flight Facility in southeastern Virginia.

Hopefully, Friday, September 16, 2005 will be long remembered as a red letter day in hurricane forecasting history.

A cluster of heavy showers has formed over eastern Jefferson County this morning. The system will bring brief heavy rains to eastern Jefferson, central and southern St. Clair, and northeastern Shelby County during the next hour. There might even be a clap or two of thunder. Additional showers are forming near I-20 across East Alabama. A slow moving cold front is pushing across the area and additional showers and storms could form this afternoon across the area.

Sunshine is limited across North Central Alabama and temperatures today will be held in the lower 80s in most locations from Tuscaloosa to Birmingham to Anniston and Gadsden.

Tropical depression seventeen has formed in the Atlantic and another system could become number 18 today north of Puerto Rico. Read down the blog for additional information on the tropics.

I hate hurricanes. I know they have a role in carrying heat from the tropics to the poles, but I still hate them. We are in the climatological peak for hurricanes in the North Atlantic, and after a brief lull, things are starting to heat up again. There are some ominous signs on the horizon.

OPHELIA: No problem here. Tropical Storm Ophelia made her closest approach to southeastern Massachusetts this morning, passing less than 100 miles southeast of the island of Nantucket. The storm will quickly lose tropical characteristics as it moves rapidly northeast heading toward the British Isles by midweek.

TROPICS STORY #2: Satellite imagery this morning indicates that Tropical Depression Seventeen has formed 370 miles east of the Windward Islands. The pulsing blob of thunderstorms has been gradually getting better organized under a more favorable upper wind pattern. This system is forecast by the GFDL (one of our more reliable tropical system models) to rapidly become a tropical storm and then a hurricane.

It is moving to the northwest. Interests in the Leeward Islands have been advised to monitor the storm. Air Force reconnaissance will investigate this afternoon. Warnings may be required there llater today. The GFDL also forecasts a quick turn to the north to the east of the islands and no threat to the U.S., which is good news

TROPICS STORY #3: This one will turn out to be the biggest story of the three. Low pressure north of the Greater Antilles may become a tropical depression north of the Dominican Republic during the next twenty four hours. This depression is forecast by the GFDL model to become a hurricane by Sunday night. It will pass across the Central Bahamas Monday evening and just south of Andros Island Tuesday morning.

The GFDL then depicts the frightening scenario of a rapidly strengthening hurricane in the Florida Straits between the Keys and Cuba that goes Category Five Wednesday. It then moves into the Gulf as a powerful hurricane. Where is goes from there is subject to conjecture. We do know that a strong ridge of high pressure is forecast to be to our west, hopefully keeping a protective shield over the southern United States, which would carry the storm to the south of the northern Gulf Coast.

It is way to early to talk about what might happen with this system, but needless to say, we will be watching it carefully.

The Saturday map discussion video is on the server at:

http://beta.abc3340.com/weather/video.hrb

The showers we had yesterday were certainly a welcome event even though everyone did not get rain. I got enough rain at my house to dampen the dust and that's about it. My friend Nathan Jones recorded a hundredth of an inch at his house which is only three-quarters of a mile from mine, so his dust was a little damper than mine. But there is still a little hope today as we will still see scattered showers. In fact, there are a few on radar at this writing over parts of Tuscaloosa, Jefferson, Fayette, and Walker counties.

After today, though, we turn dry again. The Birmingham airport, the official observation site for the area, recorded only 3 hundredths of an inch of rain, so September, 2005, could still be one of the driest Septembers on record.

Note in the post below this one that we have a special statement from the National Hurricane Center on a developing tropical depression. That system should be a tropical depression later this morning or early this afternoon. I would not be surprised to see it become Philippe within 24 hours. Convection seemed very strong on the infrared satellite view. Computer models are suggesting that disturbance could stay east of the Leeward Islands which would be great news for the Gulf of Mexico. We just don't need to see a storm of any strength come into the Gulf where a large part of the central Gulf coast is extemely vulnerable.

I started the weekend off with some great music last night as my wife and I attended the Alabama Symphony Orchestra's performance at the Alys Stephens Center. It included the world premiere of music by composer Michael Torkee. It was wonderful and very uplifting to hear such fine music.

I hope everyone has a great weekend. Stay safe.

-Brian-

Here we go for the seventeenth time this year! The National Hurricane Center issued the statement below at 7:20 am CDT on the newly developing tropical depression east of the Windward Islands. If this should develop in a tropical storm - and there is reason to believe it will - it will be named Philippe.

-Brian-

SPECIAL TROPICAL DISTURBANCE STATEMENT
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
720 AM CDT SAT SEP 17 2005

...SEVENTEENTH TROPICAL DEPRESSION OF THE SEASON FORMING EAST OF THE
WINDWARD ISLANDS...

SATELLITE IMAGERY THIS MORNING INDICATES THAT THE VIGOROUS TROPICAL
WAVE ABOUT 370 MILES EAST OF BARBADOS HAS BECOME BETTER ORGANIZED
AND THAT A TROPICAL DEPRESSION IS FORMING. THE FIRST ADVISORY ON
THE SYSTEM...POSSIBLY INCLUDING WATCHES OR WARNINGS FOR PORTIONS OF
THE LESSER ANTILLES...WILL BE ISSUED AT 11 AM AST...1500Z.

AN AIR FORCE RESERVE HURRICANE HUNTER AIRCRAFT WILL INVESTIGATE THIS
SYSTEM THIS AFTERNOON.