End of Hurricane Season - 2007

[Groomlakearea51]

Christy; I feel for you up there. You are also gonna get something off that mess in the gulf that's headed towards Texas. Hopefully, just some rain...

I'll keep posting the supercomputer tracks as we get them.

One of my many jobs is the "liaison officer" to our Emergency Management Office. I have to look, download, analyze, and report to the Sheriff as these things unfold. When they arrive, I am "on the street" with a satellite phone, spotlight, raingear, radio and a sub-machine gun (for close encounters with possible looters...) with the diesel pick-up as they go through.

Talk about a wild ride!!!! 115 mph winds coming sideways as I'm cruising at about 5 mph down the roads locating the downed power lines, etc. Good thing the pickup weighs 7500 pounds. During Wilma, it was "rockin",... literally.

[dtel's wife]

As much as I hate to say it....it really is somewhat comforting to know someone out there in law enforcement can understand how bad the affects me, as well as others, emotionally.

It's tough, really tough....you have to decide where, when and if to evacuate...depending on the forecast track. You can only take so much of your "stuff", pictures (which we have been busy putting on CDs), and home videos (which we have been busy putting onto DVDs), very little clothing, medicines, "important" papers, etc. The decision to evacuate can be totally overwhelming in and of itself.

My in laws had come over to south Mississippi two days before Katrina, my mother-law woke up at 4:30 a.m. and said...."Christy did you pack you suitcases?" (They had been sitting in the living room for two days!)....I said, "Yes maam"....then she said...."Did the forecast track change?" I said, "No maam." Then she said...."What time are we leaving for north Louisiana?"

Then looking at the television while sitting in north Louisiana it became readily apparent we were in for big trouble....It is horrible....not knowing if your house is blown away or not and everything else that goes with it.

Groomlake....what is your "gut" feeling on Dean? It really looks as though it is going to make it into the Gulf of Mexico, at the very least???

[CECAA850]

Groomlake....what is your "gut" feeling on Dean? It really looks as though it is going to make it into the Gulf of Mexico, at the very least???

IMO it's too early to tell. Trust me, I watch them like a hawk. The eye of Rita went right over Beaumont 2 years ago. I haven't forgotten.

[dtel's wife]

CECAA,

Yes, I know it's still too early to tell. I watch them like a hawk also. I know you guys got a hard hit from Rita...it was a double hit for Louisiana on the heels of Katrina.

If they don't change the forecast track in the next twenty four hours it looks like it will make it into the Gulf.[]

I spoke to Groomlake earlier tonight and he kind of agrees....we just have to wait and see.

[jacksonbart]

Hey I have a lot of cans of ravioli.

[dtel's wife]

jacksonbart:

Is that an offer? Should all of us Gulf Coast state residents start sending you our addressess?????[]

[jacksonbart]

Actually just looking for a can openner, preferably electric. Wait, I guess that would defeat the point.

[dtel's wife]

jackson,

I've got one or two manual can openers I could trade for a couple cans of ravioli if we get really desperate down here![] That would still leave me with my electric can opener, which would defeat the purpose and one manual can opener![]

[Groomlakearea51]

TS Dean continues west but the supercomputer models continue to "drop" the track down slightly. The majority, unfortunately, indicate that the storm will either hit Cuba then to the Gulf, or pas to the south through the Yucatan Gap into the Gulf. Either scenario is not good due to their estimates of what will happen as it gets into the Carribean (and the Gulf). NHC stated this morning:

SHOULD RESULT IN A GENERAL WESTWARD TO WEST-NORTHWESTWARD MOTION. THERE HAVE BEEN SOME CHANGES IN THE MODEL GUIDANCE...AS THE CANADIAN AND ECMWF MODELS HAVE SHIFTED FROM A WEST-NORTHWESTWARD TRACK TOWARD THE BAHAMAS TO A MORE WESTWARD MOTION THROUGH THE CARIBBEAN. THE UKMET CONTINUES TO CALL FOR A GENERAL WESTWARD MOTION...WHILE THE GFS CALLS FOR A WEST-NORTHWESTWARD MOTION NEAR THE END OF THE FORECAST PERIOD. THE NEW FORECAST TRACK IS SIMILAR TO THE PREVIOUS TRACK THROUGH 72 HR...THEN SHIFTED A LITTLE WEST OF THE PREVIOUS TRACK THEREAFTER BASED ON THE OVERALL CHANGE IN THE ENVELOPE OF GUIDANCE. THE NEW TRACK IS IN BEST AGREEMENT WITH...BUT A LITTLE SLOWER THAN...THE GFS. DEAN SHOULD ENCOUNTER WARMER SEA SURFACE TEMPERATURES ALONG THE FORECAST TRACK...AND THE VERTICAL SHEAR IS FORECAST TO BE LIGHT DURING THE FORECAST PERIOD. THE INTENSITY GUIDANCE CALLS FOR STEADY STRENGTHENING...AND SO DOES THE INTENSITY FORECAST IN BEST AGREEMENT WITH THE ICON CONSENSUS. GIVEN THE FAVORABLE UPPER-LEVEL WINDS AND WARM WATER...THERE IS A POSSIBILITY THAT DEAN COULD BE NOTABLY STRONGER THAN FORECAST BY THE END OF THE FORECAST PERIOD.

FORECAST POSITIONS AND MAX WINDS

INITIAL 15/0900Z 12.2N 44.2W 45 KT
12HR VT 15/1800Z 12.4N 46.6W 50 KT
24HR VT 16/0600Z 12.8N 50.1W 55 KT
36HR VT 16/1800Z 13.2N 53.7W 60 KT
48HR VT 17/0600Z 13.8N 57.1W 70 KT
72HR VT 18/0600Z 15.0N 63.0W 80 KT
96HR VT 19/0600Z 16.0N 68.5W 90 KT
120HR VT 20/0600Z 17.5N 74.0W 100 KT

[Groomlakearea51]

TS Dean's "Cone of Death" Version........

[Groomlakearea51]

TS-5 (The one in the Gulf..)

Per the NHC: UPPER-LEVEL WINDS ARE QUICKLY BECOMING FAVORABLE FOR STRENGTHENING AS AN UPPER-LEVEL ANTICYCLONE HAS FORMED OVER THE CENTRAL GULF OF MEXICO. THIS EVOLUTION IS RESULTING IN A REDUCTION IN VERTICAL SHEAR AND A MORE DIFFLUENT PATTERN ALOFT. STILL...THE CURRENT LACK OF ORGANIZATION ARGUES AGAINST SIGNIFICANT STRENGTHENING. EVEN IF THE DEPRESSION CAN BECOME BETTER ORGANIZED LATER TODAY...IT WOULD ONLY HAVE A DAY OR SO OVER WATER. THE OFFICIAL INTENSITY FORECAST THEREFORE CALLS FOR A LITTLE STRENGTHENING PRIOR TO LANDFALL. ONCE INLAND...THE DEPRESSION SHOULD QUICKLY WEAKEN WITH DISSIPATION BY DAY 3...IF NOT SOONER.

A TROPICAL STORM WARNING MAY BE REQUIRED FOR PORTIONS OF THE SOUTHERN TEXAS COAST LATER TODAY.

FORECAST POSITIONS AND MAX WINDS

INITIAL 15/0900Z 24.6N 91.8W 25 KT
12HR VT 15/1800Z 25.3N 93.2W 30 KT
24HR VT 16/0600Z 26.4N 95.2W 35 KT
36HR VT 16/1800Z 27.3N 97.0W 40 KT
48HR VT 17/0600Z 28.0N 98.9W 25 KT...INLAND
72HR VT 18/0600Z...DISSIPATED

[Groomlakearea51]

TS-5 really won't need a "Cone of Death", so a "Cone of Moderate Discomfort and General Aggravation" would be more apt:

[Groomlakearea51]

Some notes for forum members following the progress of these storms:

http://www.nhc.noaa.gov/ is the Main National Hurricane Center site. Plenty of graphics and plenty of arcane stuff if you are interested.

The NHC releases new updates as required, generally at: 5:00; 8:00; 11:00; 2:00 PM; 5:00 PM, and again at 11:00 PM EDT (Eastern Daylight Time).

They also use military time on many products. If you see a time of say, 1530 hours, that's 3:30 PM. 12 hours + 3 more hours+ 30 minutes = 15 hours & 30 minutes ) or "1530 hours" , etc.

If you see a chart/ graphic or report that says UTC; that means Universal Time, or Greenwich Mean Time (GMT). You may also see "Zulu" or "Z" time. That's also the same as UTC/GMT. That's 5 hours ahead of Eastern Daylight Time. Example: if the time is 1500Z that would be 1500 hours = 3:00 PM, minus -5 hours, which equals 1000 hours, or 10:00 AM

http://www.sfwmd.gov/org/omd/ops/weather/plots.html is the site to look at the actual super-computer plotting tracks. Please note:

- Each model utilizes different assumptions and different calculations which leads to different models performing better in different situations.
- All models have unique biases.
- Some models utilize statistics, some utilize physics formulas, some utilize a combination of both.
- Some models perform best with weaker systems, others perform best with well-developed, purely tropical systems.
- The spread of the various model solutions can give a sense of the uncertainty associated with a particular storm track. However, some of the models are interrelated as they share the same initial analyses or the same global forecast fields. Therefore, clustering of model solutions does not necessarily indicate truely independent agreement.
- The National Hurricane Center has access to many other models and data not included in these products. At times, these other models and data have a significant impact on the forecast track issued by the National Hurricane Center.
- Further information on some of the models used by the National Hurricane Center can be found at the National Weather Service Southern Region Headquarters website as well as the Hurricane Research Division website.

http://www.nhc.noaa.gov/pdf/AT_Track_chart2.20060925.pdf is a good pdf chart you can print out and use to plot the course of destiny.....

Other than watching these things and being prepared, there is not much you can do. Track paths can vary as much as 250 miles in either direction from the forecast track from the NHC.

Hope that is of some assistance to forum members who are concerned about what's happening, or are interested in this.

[CECAA850]

Groom (can I call you that[]. Would a TS such as is in the Gulf now, create a low pressure zone that Dean would be prone to follow? I know high pressure pushes them away.

[Groomlakearea51]

cecaa850: That's alot better than some of the other things I've been called in my life!!! LOLOL[]

They travel by way of the rotation of the earth and the results of the coriolis effect. They are, by nature, very low pressure, more than normal low pressure areas. So they tend to follow the ridges, but that's a minor factor in the overall scheme. They apparently "bump" against high pressure ridges and careen off.... sort of a weird demented pinball machine with strange moving bumpers that bump at certain altitudes, but maybe not at others.... What also steers them is upper level jet stream, troughs and "bulges". There's a TAFB product on the NHC site called a unified surface analysis. Look at that and look at what's in front of Dean in the way of frontal boundaries, high and low troughs, etc. That will give you a better sense (or confusion!!) as to why it may go north or south of the extrapolation line.

[CECAA850]

Dang, I was looking for a simple answer. Something I could wrap my little brain around. Thanks.

[Groomlakearea51]

NHC 8:00 AM update:

BASED ON 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1015 UTC.

TROPICAL STORM DEAN IS CENTERED NEAR 12.2N 44.2W AT 15/0900 UTC MOVING W AT 16 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 1000 MB. MAXIMUM SUSTAINED WIND SPEED IS 45 KT WITH GUSTS TO 55 KT. THE ASSOCIATED DEEP
CONVECTION REMAINS SLIGHTLY DISPLACED TO THE W OF THE CENTER DUE TO EASTERLY SHEAR BANDING IS BEGINNING BUT IS CURRENTLY NOT WELL ORGANIZED. SCATTERED MODERATE/ ISOLATED STRONG CONVECTION IS FROM 10.5N-13N BETWEEN 42.5W-45W. THE SYSTEM CONTINUES TO MOVE RATHER
BRISKLY ALONG THE SOUTHERN PERIPHERY OF A DEEP LAYER RIDGE. AS DEAN CONTINUES TO APPROACH THE LESSER ANTILLES IT WILL BEGIN TO ENCOUNTER WARMER WATER AND LESS WIND SHEAR AND WILL LIKELY BECOME A HURRICANE AS IT NEARS THE ISLANDS.

(GULF STORM) TROPICAL DEPRESSION FIVE IS CENTERED NEAR 24.6N 91.8W AT 15/0900 UTC OR ABOUT 320 NM ESE OF BROWNSVILLE TEXAS MOVING NW AT 9 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 1006 MB. MAXIMUM SUSTAINED WIND SPEED IS 25 KT WITH GUSTS TO 35 KT. SYSTEM HAS NOT BECOME MORE ORGANIZED DURING THE NIGHT WITH SATELLITE IMAGERY HINTING AT MULTIPLE LOW LEVEL CENTERS. SCATTERED MODERATE/STRONG CONVECTION IS WITHIN 150 NM OF THE CENTER OVER THE N SEMICIRCLE. ALTHOUGH UPPER LEVEL WINDS ARE BECOMING MORE FAVORABLE FOR FURTHER DEVELOPMENT THE LACK OF
CURRENT ORGANIZATION AND THE LIMITED TIME THE SYSTEM WILL REMAIN OVER WATER THIS SYSTEM IS NOT EXPECTED TO STRENGTHEN TOO MUCH.

[Groomlakearea51]

Dang, I was looking for a simple answer. Something I could wrap my little brain around. Thanks.

For perhaps a good simple way of looking at them: They do travel in the low pressure areas, bouncing off, or being steered by high pressure ridges, but can also be steered by upper level winds.

How they travel, the courses they take, their intensity, etc. is still very difficult to really accurately predict past about 36-72 hours. Even the "supercomputers" don't agree. The problem is the weather.... it changes all around the systems as they move. As other things happen, often thousands of miles away, they begin to alter the outcomes of the various predictions. The predictions get "fuzzy" after about 36 hours, as noted on the SFWMD track path graphic. If you were able to "freeze" all factors, except the earths rotation, then where it would go would be really easy to predict. As far as intensity... surface temps, wind shear at upper levels, etc. etc. all play a part. As long as the conditions "favorable for development" (as NHC so casually calls them) remain, the longer it lives, the stronger it gets. It's a giant heat exchange by convection machine - keep feeding it, it gets bigger.... It's also been characterized as a "bazillion thunderstorms, all next to each other, sucking up water from the ocean, rotating in bands". Remove the warm water temps (and the water...), it starves to death. Which is what happens when it starts passing over land.

Hope that helps a bit.

[Groomlakearea51]

Somebody just called me who will remain nameless....[] They asked why hurricanes rotate in the same direction as the water when they flush their toilet... []

The counterclockwise rotation of hurricanes in the northern hemisphere is due to the Coriolis force/ effect. This force causes wind currents in the Northern Hemisphere to drift to the right. When the wind currents converge toward the low pressure core, they set up a counterclockwise circulation pattern. This same effect is at the micro level for folks who get tornados... In the southern hemisphere, the direction of the Coriolis force causes wind currents to drift to the left and large-scale low-pressure systems to rotate in a clockwise direction.

Related to that (unfortunately), the forward speed of a hurricane is very dangerous in terms of the strength. The forward speed must be added to the internal wind speeds on the north-right side of a storm, and it can take a Category 1 storm and effectively make it a Category 4 in a narrow region or in the bands. In effect, the forward speed of 20 mph, with a speed of 75 mph in the bands themselves, will be seen by the observer on the ground as 95 mph.

That's why, as an example, Andrew, even thjough it was a relatively small size, was so powerful and was a Cat-5 on it's north-east side, it was a very, very fast mover.... Katrina, while powerful, was not so much the product of the forward "speed", but the convection over the Gulf - hot water for fuel....

[Dflip]

How they travel, the courses they take, their intensity, etc. is still very difficult to really accurately predict past about 36-72 hours. Even the "supercomputers" don't agree. The problem is the weather.... it changes all around the systems as they move. As other things happen, often thousands of miles away, they begin to alter the outcomes of the various predictions. The predictions get "fuzzy" after about 36 hours, as noted on the SFWMD track path graphic. If you were able to "freeze" all factors, except the earths rotation, then where it would go would be really easy to predict. As far as intensity... surface temps, wind shear at upper levels, etc. etc. all play a part. As long as the conditions "favorable for development" (as NHC so casually calls them) remain, the longer it lives, the stronger it gets. It's a giant heat exchange by convection machine - keep feeding it, it gets bigger.... It's also been characterized as a "bazillion thunderstorms, all next to each other, sucking up water from the ocean, rotating in bands". Remove the warm water temps (and the water...), it starves to death. Which is what happens when it starts passing over land.

If you remember the last couple of years, even the projections three hours out are subject to error. I'm talking about where the eye of the hurricane hits, even with Katrina the 3 hour projection had it hitting New Orleans, instead it skipped just to the east. A similar occurrence happened with Charley as it hit Punta Gorda, Florida, instead of the Tampa area.

The early projections do give you an idea whether you need to get out of the coastal area where you live because it will take a day plus to get out of the area with all of the traffic. When you start projecting three days in advance of a storm that is not yet a hurricane, well you have seen the margin of error, Puerto Rico to Cuba. For the US that is an error of northern Florida to Brownsville, Texas. So the best bet is to see where the projection is in two days and make plans if necessary. Please also consider the excellent advice by dtel's wife regarding having canned goods available because when you return you won't have electricity. Loading up the freezer with ice was also a great idea.

Remember from Katrina and a few others, if it hits a high 4 or 5 level, expect a huge storm surge to come with it. The winds might die down to a 3, but the storm surge is the largest killer and destructor with hurricanes. The surge does not die down to the same level as the winds above.