Florence still a weak tropical storm

By: Dr. Jeff Masters , 1:54 PM GMT on September 06, 2006

Florence still looks pretty disorganized, with a large, sloppy center and some clumps of heavy thunderstorms on the east side. Wind shear of 10-20 knots due to upper-level westerly winds is causing much of this disorganization. Part of Florence's struggles are due to her inability to overcome her initial indecision on where her center of circulation should be. In any case, Florence remains a weak tropical storm today. Only slow intensification should happen today. This morning's QuikSCAT satellite pass found only 40 mph winds in Florence, although it did miss sampling the most intense portion of the storm.

Intensity forecast
The winds shear forecast is a bit more uncertain today. An upper-level low to the west of Florence that is creating the shear is forecast to move away, allowing Florence to intensify to a hurricane (and possibly a major hurricane) over the next four days. However, the speed with which this upper low may move off is uncertain, and a slower than expected movement way will keep significant winds shear over Florence. The disturbance about 800 miles to the east-southeast may also steal some energy from Florence over the next few days.

Track forecast
The computer models had a better-defined storm to track with their more recent runs, and should be reasonably reliable today. The disturbance "Invest 91L" about 800 miles to the east-southeast of Florence may still cause some trouble if it develops into a tropical depression, however. When two storms get within 13 degrees of arc of each other (900 miles), they can interact (the Fujiwhara effect), causing difficulties in the track and intensity forecasts.

The models have a very believable scenario where Florence moves north of the Lesser Antilles Islands, then turns northward in response to a trough of low pressure swinging across the Eastern U.S. four days from now. On this trajectory, Florence would only be a threat to Bermuda and perhaps the Maritime provinces of Canada. When one consults the map of historical paths of September tropical storms that have tracked near Florence's current position, we see that only one of these previous storms managed to hit the U.S. East Coast. I will be surprised (though not amazed) if Florence does manage to strike the U.S.

Florence's little brother
Tropical disturbance 91L, about 800 miles east-southeast of Florence, is a little less organized than yesterday. The disturbance's close proximity to its big sister is probably hampering its development. Some of the computer models predict that 91L will never escape the shadow of big sister, following her on a recurving path out to sea between Bermuda and the U.S. East Coast and never developing into a tropical storm. However, some of the models predict that when Florence gets pulled sharply north, this will open up enough separation between the two storms to allow 91L to split away and intensify.

Figure 1. Preliminary model tracks for Invest 91L, the tropical wave 800 miles to the ease-southeast of Florence.

A stalled cold front off the Carolina coast has spawned a low-pressure area with a clump of intense thunderstorms a few hundred miles off the Florida/Georgia coast. This low is expected to track north-northeast and pass near the Outer Banks of North Carolina Thursday morning. A second low may develop in a similar location on Thursday and pass by the Outer Banks on Friday morning. Neither of these lows have enough time to develop into tropical depressions.

Ioke is finally gone! It turned into a powerful extratropical storm with 60 mph winds yesterday over the ocean waters east of Japan.

Next update
I'll have an update Thursday morning, unless there's something interesting to report on this afternoon.

Jeff Masters

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1323. leftyy420
1:02 AM GMT on September 07, 2006
back to the weather i also think some of us need to consider option 3.

3. the storm loops as the weakness closes. than who knows what most likly the next trof shoots her north but theres a chance at even a jeane like scenario. just throwing that out there casue i been thinking bout the ukmet and the last run has a bend back and the gfs is so hard with tis turn and next the slowdwon predicted by all the models now around day 4 and 5. Remebr if there is a slowdwon we have weka steering currents and thats where models fail specialy predicting loops. once again just a 3rd option
Member Since: August 24, 2005 Posts: 35 Comments: 1987
1322. leftyy420
12:58 AM GMT on September 07, 2006
scienceop i hope this helps. how i see it is any matter over abosolute zero gives off some form of ir radiation.

Planck's radiation law
A law of physics which gives the spectral energy distribution of the heat radiation emitted from a so-called blackbody at any temperature. Discovered by Max Planck, this law laid the foundation for the advent of the quantum theory because it was the first physical law to postulate that electromagnetic energy exists in discrete bundles, or quanta. See also Heat radiation; Quantum mechanics

computers use algorithms to make out the ditinct diff in the radiation detected. thes erae extremly sensitev peices of equipment. Those computer genrated graphics or cgi are overlayed on a visible sat image or cgi image generated to show the surface clouds to give u the ir image. its simple physics if u want the pure hardcore science. the easiest thing to undertsand is it detects tempature not heat thouhg by def heat is anything over abolsute 0 right? there for anyhting over aboslute 0 gives off heat. ir detects heat
Member Since: August 24, 2005 Posts: 35 Comments: 1987
1321. leftyy420
12:49 AM GMT on September 07, 2006
scienceop ir detects tempature both cold and warm. well i think any temp over abolute 0. all its doing is showing cloud top temp.
Member Since: August 24, 2005 Posts: 35 Comments: 1987
1320. hurricane79
12:43 AM GMT on September 07, 2006
guess everyone took a break???
1319. hurricane79
12:32 AM GMT on September 07, 2006
WG03, agreed, I will take the alternatives and try to support them
1318. ScienceCop
12:13 AM GMT on September 07, 2006
Posted By: leftyy420 at 10:59 PM GMT on September 06, 2006.
Posted By: killdevilmax at 11:06 PM GMT on September 06, 2006.
Posted By: hurricane79 at 10:58 PM GMT on September 06, 2006.

Thanx for the answers, but I am looking for deeper details.

The assumptions and explanations is these are "colder" cloudtops, and more rain, but what we see is nothing else but IR photons being received by a detector. IR is heat not coolth, so we are looking at heat radiation, not condensation, although that is being assumed that condensation forces release of heat radiation.

That these are occuring in thunderstorms is a given. That thunderstorms have peak convection is a given. One bolt of lightning is energy in the megawatts, and it lasts for brief seconds of time. These IR emissions last for hours, and in IOKE they spanned a sequence of 39 consecutive hours.

What I want to try to get at is the estimated energy value per green pixel. Every gram of water has 600 calories of heat released as it condenses, and the rainfalls given by the NHC in peak events are sometimes "20 inches of rain in mountains and isolated locations". That's a lot of heat energy, and I am trying to quantify it.

I am also trying to double-check my assumptions that this is the 10.7-10.8 micron frequency, and that right shift into the green is actually increased photon reception.

The current and recent images from Floater 1 on Florence show the green intensity. What I would like to do is nail down how much of this is from condensation and how much heat energy is being made by lightning.

Florence has no actual eye, and eye's rarely form until after a storm has reached hurricane intensity so I am told. These heat flashes are not connected to vortex activity, as they appear in regular large thunderstorms over land.

There is some complex mixture of lightning heat emissions and condensation heat emissions going on, and I am trying to determine what values the Funktop images have in determining total heat emissions or discriminating amonst several sources.

The heat likely represents brisk thermals which may have a role in eventual eye formation, and that question too revolves around the level of details that can be gleaned from imagery.

1317. hurricane23
12:00 AM GMT on September 07, 2006
Guys iam seeing a due westward motion with Florence at the moment.
Member Since: May 14, 2006 Posts: 8 Comments: 13857
1316. stormybil
11:36 PM GMT on September 06, 2006
can anyone tell if the trof is moving down faster than flo is moving thanks .
1315. o22sail
11:30 PM GMT on September 06, 2006
My gut tells me this is a Mid-Atlantic States storm.
Either that, or I'm hungry. :-)
Member Since: August 27, 2005 Posts: 0 Comments: 124
1314. Skyepony (Mod)
11:27 PM GMT on September 06, 2006
79~ Cloudsat so better illistrates your point that it's not nessesarily the highest cloud tops dropping the rain. Cloudsat is a sliced sideways view, clouds & rain. Gives you a very unique look of the storm & it's structure..once every few days. Terriable for tracking. lol. I use what you do for that. All the info hasn't hit for that last pass yet, it was close but I think a little west to get Florence.
Member Since: August 10, 2005 Posts: 346 Comments: 42054
1313. WPBHurricane05
11:27 PM GMT on September 06, 2006
if Florence does move slower, and the trough keeps moving along, its a completely different focus on where this storm would be coming

do the models not realize that 91L is behind it, and if not would that even have a diffrence in the track?
Member Since: July 31, 2006 Posts: 56 Comments: 8112
1312. killdevilmax
11:26 PM GMT on September 06, 2006
Since the models have difficulty predicting intensity, a rapid intensification could overcome marginal steering currents ahead of it. After the models digest the new intensity the forecast would change accordingly. Flo will be a good example as it is now trying to get it's convection coupled with it's center all the while fighting wind shear and dry air ingestion. It will be interesting if it will prevail. I think it will be at hurricane status tomorrow.
Member Since: August 28, 2005 Posts: 0 Comments: 324
1311. Rick54
11:25 PM GMT on September 06, 2006

A couple of questions....

At this point what are the alternate scenarios that could cause the flo to go off track to the West?

Also what is your take on the fate of 91L.?
1310. Poptartcafe
11:25 PM GMT on September 06, 2006
New blog is up
1309. PBG00
11:25 PM GMT on September 06, 2006
It worked!!!new blog
Member Since: October 20, 2005 Posts: 14 Comments: 6650
1308. weatherguy03
11:24 PM GMT on September 06, 2006
79 why is your forecast track and cone so far west? What are your resaons?
Member Since: July 5, 2005 Posts: 592 Comments: 29708
1307. Gatorx
11:24 PM GMT on September 06, 2006

I don't know if your still on here...but you are by far the nicest person I have ever heard on a blog...always positive and uplifting others...God Bless You.
1306. hurricane79
11:23 PM GMT on September 06, 2006
Maybe if we started chanting, he will update the blog... It would only take a few minutes...LOL
1305. hurricanuck
11:23 PM GMT on September 06, 2006
Not an expert, just an avid weather watcher for many years, especially the tropics. I think the folks in Atlantic Canada ought to keep a very close eye on Flo. It appears to me (after viewing the latest models) that she may be headed for the eastern tip of Nova Scotia next week. In 2003, Hurricane Juan made landfall in this area as a strong cat1. Making him one of the strongest hurricanes to hit Atl. Canada. I fear that Flo may be even stronger, perhaps a cat2, depending on its forward speed.
1304. nash28
11:22 PM GMT on September 06, 2006
Well, I'm know Dr. Masters has a family so I am not gonna bust his chops for not updating more often. However, if she slows more and the trough stalls, that changes the whole ballgame.
Member Since: July 11, 2005 Posts: 190 Comments: 16972
1303. iahishome
11:21 PM GMT on September 06, 2006
I see some Northward movement in Flo's little caboose (91L). Does that imply we might see an unexpected southern shift in Flo a'la Fujiwara?
Member Since: July 24, 2005 Posts: 5 Comments: 501
1302. hurricane79
11:20 PM GMT on September 06, 2006
Thanks Nash, there is no reason for a response like he/she had. I also assume that DR. Masters may have a new blog up shortly. With a system like Florence out there, I would think he would update more than once a day, especially with the traffic he gets
1301. stormybil
11:19 PM GMT on September 06, 2006
and to add if flo slows down anymore like she has bben the last two days she will miss the trof . and go her own way . then lets see the models go krazy anyone agree .

by the way is the trof moving down faster than flo is moving ? this can be a big change
1300. NCsnidget
11:18 PM GMT on September 06, 2006
Is it possable that if it gets strong enough will it create its own path?

To an extent when they can get to where they can effect other systems, but even the strongest storm will fall apart if it goes into areas with too much shear, too dry, water's too cold, etc.

It isn't like it gets strong enough it can ignore all the other weather patterns and go in some way that would be improbable for any storm to go.
1299. hurricane79
11:18 PM GMT on September 06, 2006
Yes it is 456, by in the dynamics of a developing tropical cyclone, an additional anticyclone develops over the system at a certain point in time. Thus, creating an additional ridging. I assume that the models have already taken this into account in theor forecasts, which is why my forecast track does curve NNW late in the track. Link
1298. PBG00
11:16 PM GMT on September 06, 2006
I'm with a unless the scenerios drastically change...If the models were not in such MAJOR agreement then i'd say maybe..but Every proffesional out there is saying the same thing..you have to trust they may actually know what they are talking about..could the situation change? absolutly.but for right now this is a fish storm.
Member Since: October 20, 2005 Posts: 14 Comments: 6650
1297. sporteguy03
11:16 PM GMT on September 06, 2006
When projecting the models though do they take into account storm speed or if a system slows down and do they have any inkling on that syatem off the East Coast?

I just think the more factors a model has to deal with the harder the track becomes...
Member Since: July 7, 2005 Posts: 0 Comments: 5658
1296. bajelayman
11:16 PM GMT on September 06, 2006
The thing is, Florence is moving pretty slowly. Building, it just took in the clouds which were SE of Barbados today.

Such slow movement makes me wary of how strong it may get and what it will do.
1295. nash28
11:15 PM GMT on September 06, 2006
Hey 79. I emailed Kiss with some more of the same sentiment. Hopefully, he'll leave. God knows he sure won't respond to me. None of the assclowns I challenged off of the blog had the balls to respond to my "what's you're f'ing problem" emails.
Member Since: July 11, 2005 Posts: 190 Comments: 16972
1294. hurricane79
11:14 PM GMT on September 06, 2006
Skyeone, the best imagery that I have found during the nighttime hours is the shortwave IR. It can pick up on smaller clouds and any subtlety that might be in the area. Link
1293. killdevilmax
11:14 PM GMT on September 06, 2006
I give FLA about 3 percent chance. Good waves maybe. That's all I expect from it on the OBX.
Member Since: August 28, 2005 Posts: 0 Comments: 324
1292. Cavin Rawlins
11:14 PM GMT on September 06, 2006
upper level anicyclone is centered south south east of Bermuda.
Member Since: July 24, 2005 Posts: 407 Comments: 19076
1291. WPBHurricane05
11:13 PM GMT on September 06, 2006
The Groups:

A. Fish Storm
B. Land Falling US

Im with A unless that trough does not pick up Florence.
Member Since: July 31, 2006 Posts: 56 Comments: 8112
1290. PBG00
11:11 PM GMT on September 06, 2006
Hey again..I see the ame story here.Why is it so hard for everyone to believe this storm is not a threat to the u.s? especially Florida?
Member Since: October 20, 2005 Posts: 14 Comments: 6650
1289. hurricane79
11:10 PM GMT on September 06, 2006
KissMyGrits I spammed your poset and would like everyone on the blog to know that my family lives in Florida, including a newborn. Wishcasting is not in my vocabulary, so BACK OFF
1288. nash28
11:10 PM GMT on September 06, 2006
Kiss- mail for you.
Member Since: July 11, 2005 Posts: 190 Comments: 16972
1287. Skyepony (Mod)
11:10 PM GMT on September 06, 2006
79~ I went looking for a cloudsat of Florence to illasrate your point. The pass missed her today.
Member Since: August 10, 2005 Posts: 346 Comments: 42054
1286. caribbeanweather
11:09 PM GMT on September 06, 2006
URNT11 KNHC 062256
97779 22544 40338 74800 01500 18017 22228 /0014

AL 92...OB 8


Nothing there yet
1285. killdevilmax
11:06 PM GMT on September 06, 2006
Science cop
I am guessing here but I think the colors represent cloud top temp.: yellow low level and warm, blue higher and cooler, red higher and cooler still, and green highest and coldest in the minus 70 to minus 80 degree range. I didn't pay much attention to John but I think it was about max intensity then.
Member Since: August 28, 2005 Posts: 0 Comments: 324
1283. hurricane79
11:06 PM GMT on September 06, 2006
I see a WNW movement, no SW movement. Still curious about the anticyclone that will develop over this system (Florence) in 36 hours
1282. Cavin Rawlins
11:05 PM GMT on September 06, 2006
Weather456s Tropical and Subtropical Weather Discussion for The North Atlantic Ocean.............Tropical Storm Florence..
Wednesday, September 6, 2006
5:00 PM AST
Updated: 7:04 PM AST

As of 5pmAST, Tropical Storm Florence was located at 19N/51.4W, moving WNW near 9mph. The storm is packing winds of 50mph and a MCP of 999mbars.

Florence has slowed this afternoon and begins to organized herself, pulling some convection near and over her center. Though the system is still not quite organized yet, the cloud structure is slowing improving, with time.

A cutoff Upper level Low has form out of the Upper Level trough that dipped into the Atlantic earlier this week. The low is moving to the SSW, which should put Florence to the North and West of the low, which is associated with low wind shear as oppose to the south side, which is the most inhibiting side (E.g. Tropical Storm Chris).

Surface Observation/Conditions
The storm is moving over waters near/above 80 degrees, so that should fuel Florence as it tracks west.

Wave heights in the open waters around TS Florence will be 10-15ftt above normal.

Buoys and Ships
Ship MSJY8, located directly inside Florence, very near its center is reporting winds of 20knots and pressure of 1005mbar. The ship also reported cloudy winds and an air temperature of 28C.

Another ship MSJZ8 located in the convection in the NE quadrant measure a pressure of 1012mbar and winds of 30knots. This ship is reporting continuous light to moderate rain, cloudy skies and an air temperature of 26C.

Two more hips to the SE of Florence measured pressures of 1011.3mbar and 1010mbar.

As the cutoff low begin to move south more, wind shear from the trough should relax allowing some intensification to occur. When Florence moves westward it will become under the influence of an upper level ridge/anticyclone/high near 60-65W, allowing modest intensification to occur and Florence could become a Hurricane, later this week.

The storm will continue westward around the southern edge of a ridge of high pressure, then turn north around the western edge of the ridge. The turn might be enhance by the progression of an upper level trough draped across the Unites States of America.

Though the United States may be speared from Florence for now, the threat is still there for Bermuda. So Bermudans need to watch the situation carefully.

According to how closed Florences moves to the Islands and Puerto Rico, some scattered showers are possible, considering how large she is.

Member Since: July 24, 2005 Posts: 407 Comments: 19076
1281. tropicallydepressed
11:04 PM GMT on September 06, 2006
Don't see the SW movement.
Member Since: August 11, 2006 Posts: 0 Comments: 139
1280. leftyy420
11:03 PM GMT on September 06, 2006

the models never ran cosnitently for days on ernesto till it apeared the mdoesl were wrong. this is not the same situation. the models have been damn enar consitent every run for 48+ hrs. give or take a few miles either way they show the same steering pattern thats already starting to play out. Strong shortwave low pressure off the coast will punhc a hole in the ridge that flow will follow. anything is always possible but in this situation u go with trends and data and all that suggests north turn. no mdel takes it past 70 w farthest i belive i have seen is 68w. thats miles from land even with errors involved going out 5 days. its looking less likly the us will contend with this and ignoring the data when its been consitent is a mistake.
Member Since: August 24, 2005 Posts: 35 Comments: 1987
1279. leftyy420
10:59 PM GMT on September 06, 2006
scienceop all it is is a measuser of the temp of gthe cloud tops. the coldeer the higher in to the atmosphere they climb a sign of intense convection or lifting due to t-storm growth. thats an east explanation.

there are diff channels of ir but they are basicaly computer depiction on the temperature. some are black and white some are enhanced with bright vibrant colors.
Member Since: August 24, 2005 Posts: 35 Comments: 1987
1278. hurricane79
10:58 PM GMT on September 06, 2006
Typically the cloud tops would represent precip below, but not necessarily in a straight up and down manner. The heaviest rain could be miles away from the coldest and highest cloud tops
1277. primez
10:58 PM GMT on September 06, 2006
lefty, I wouldn't rule it out if I were you.

Does Ernesto ring a bell? Remember how ALL of the models were forecasting a Gulf coast landfall? Did that happen?
Member Since: September 18, 2005 Posts: 0 Comments: 195
1275. ScienceCop
10:55 PM GMT on September 06, 2006

I am doing some personal research on the infrared effects shown on some satellite imagery.

An example of the question is posted here (graphics intensive, slow loading for dial-up)...


Example: Hurricane John IR Emissions

Previous to 2006 I was unaware of the "Funktop" color scheme used for preciptiatation analysis. Google is unhelpful in giving descriptions. Perhaps someone can help further explain the color scheme.

There is no doubts that the pixels information is the same as the AVN, IR4, Rainbow, and other IR channel 4 enhancements, only a different color palette being used.

The color key at bottom has a green band which rarely appears in pictures. My assumption is it is taken in the 10.7 to 10.8 micron band.

The color "represent" some event(s) ocurring, but the actual data is IR photons arriving at a detector at geostationary orbit. The rightmost bands of green and white are increased levels of photons arriving.

They are taken to represent cloud height (higher clouds issue more IR photons closer to the receiver), and taken to represent temperatures (higher clouds are in colder air regions), with the combination representing more moisture being squeezed into condenation by the higher colder altitudes.

The IR photons themselves are the latent heat carried by water vapor, which is forced to be emitted by condensation. This high altitude forcing of IR emissions then appears on the image coded to highlight the IR flashes as representing rainfall of high density.

If anybody has a better explanation or finds fault with this explanation, I would appreciate email reply, as it is too easy to miss a reply on a blog with 1000 entries that one never revisits after the newer blog entry is posted.

Thank you,
1274. killdevilmax
10:55 PM GMT on September 06, 2006
No eye. Cold high cloud tops from convection inching towards the COC. If it can overcome the dry air ahead of it and the wind shear it will be a hurricane tomorrow. JMO. How fast is it moving now lefty?
Member Since: August 28, 2005 Posts: 0 Comments: 324
1273. leftyy420
10:55 PM GMT on September 06, 2006
hellsniper and i would be with you but that is not and has not happened. for days now all the models called for a recurve out to sea. for days. not one model has called for a landfall on the mainland of the us. not 1
Member Since: August 24, 2005 Posts: 35 Comments: 1987

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