Posted on 09/03/2006 1:44:19 PM PDT by nwctwx
Statement as of 11:00 am EDT on September 09, 2006
the initial motion estimate is 305/11...based mainly on continuity with the previous forecast track and 09/1007z SSMI and 09/1015z Quikscat overpasses. The basic forecast track and reasoning remains unchanged from previous advisories. Florence is expected to gradually round the southwestern and western periphery of the subtropical high and move northward through a break or weakness in the ridge that is forecast by all the models to develop in 36-48 hours. The official forecast track is close to the previous track and the NHC model consensus.
Satellite estimates of 65 kt...77 kt...and 90 kt from SAB...TAFB... and AFWA...respectively...suggest that Florence could be a hurricane. However...aforementioned microwave data suggest that the mid-level circulation is tilted 12-18 nmi northwest of the low-level center and that there was no eye feature present. Therefore...the initial intensity was only nudged upward slightly and an Air Force reconnaissance aircraft around 18z will determine whether or not Florence is a hurricane. The intensity forecast also remains unchanged from the previous advisory and is a blend of the GFDL and SHIPS intensity models.
Forecast positions and Max winds
initial 09/1500z 24.7n 63.7w 60 kt
12hr VT 10/0000z 25.9n 64.8w 70 kt
24hr VT 10/1200z 27.7n 65.7w 75 kt
36hr VT 11/0000z 29.7n 65.9w 85 kt
48hr VT 11/1200z 31.9n 65.3w 90 kt...near Bermuda
72hr VT 12/1200z 37.6n 61.6w 85 kt
96hr VT 13/1200z 44.0n 54.0w 70 kt...becoming extratropical
120hr VT 14/1200z 49.0n 44.0w 60 kt...extratropical
$$
forecaster Stewart
It certainly looks like a hurricane now. And the core is finally now starting to run more northerly with the rest of the surrounding weather, but not as rapidly as it appeared to be yesterday afternoon. It is interesting to hear the discussion about the NW tilt of the midlevel circulation. I've got to look into how to determine that. My lack of understanding of that is probably what had me calling the location so differently yesterday.
The more interesting question to me now is how rapidly this will intensify. It seems it could go up very rapidly now, but there's a race now with how rapidly it decides to turn toward the north.
Not this time.
It looks like Flo is still sucking in some dry air from time to time - it was looking very robust and now the convection is fading to the S and E of the circulation a bit.
* NOAA's Climate Prediction Center says an El Niño is setting up in the Eastern Pacific that could cut short the Atlantic hurricane season.
It can't be said with certainty, but the 2006 Atlantic hurricane season might come to a premature end soon.
The Climate Prediction Center, an agency under the National Oceanic and Atmospheric Administration, said Thursday that an El Niño is forming in the eastern Pacific and that this cooling of waters could cut short the Atlantic hurricane season.
Hurricane season runs from June 1 through Nov. 30, and last year a number of storms in November and December. This Sunday is considered the peak of hurricane season.
Predictions of an active 2006 hurricane season were based on the presence of warmer Pacific waters last May, an event called La Niña.
When Pacific waters off Central and South America are warmer than normal, winds over the Atlantic tend to calm down. There is an absence of what is called shear, winds that can blow the cloud tops off developing storms.
When El Niño forms, winds over the Atlantic become strong from the west. As Atlantic systems move westward toward Florida and the United States, the developing storms meet strong upper-level winds and are torn apart.
That's what is beginning to happen now, the Climate Prediction Center says.
Dr. Jeff Masters of Weather Underground calls the El Niño "unusual" for this time of year and says because of that no one can be sure exactly what will happen next.
"El Niño conditions put a major damper on both the number and intensity of Atlantic tropical cyclones," Masters wrote on his Web site Friday. "If the Climate Prediction Center is right," he added, "we can expect an earlier than usual end to hurricane season in the Atlantic and a quiet November and December."
If the El Niño is long-lived, as previous ones were, "it will probably last through the hurricane season of 2007, helping to suppress hurricane activity next year," Masters added.
The formation of El Niño at this time of year has happened only once in the last half-century. For this reason, Masters said, many researchers say global warming is behind the water temperature changes.
And for the upcoming winter, El Niño will mean wetter than normal conditions for Florida and the Southeast. Temperatures will be slightly below normal, mostly due to the excessive cloud cover, the climate center says.
LOL. They had to make sure the sheeple understand that whether the hurricane season is active or not, global warming is still to blame.
"... an El Niño is forming in the eastern Pacific and that this cooling of waters could cut short the Atlantic hurricane season."
Therefore:
"... researchers say global warming is behind the water temperature changes."
HUH??? Cooling is a result of warming?
And "researchers" wonder why people don't trust them?
Maroons.
The 2PM update by NHC still has Flo as a Tropical Storm.
I'll be very surprised if it isn't called "hurricane" very very soon, though.
That would be very good news.
And in the last few hours, it looks much more ragged. This is the storm that just cannot make up its mind.
Vortex Data Message:
000
URNT12 KNHC 091936
VORTEX DATA MESSAGE
A. 09/19:25:30Z
B. 25 deg 21 min N
064 deg 02 min W
C. 850 mb 1383 m
D. 45 kt
E. 306 deg 069 nm
F. 016 deg 050 kt
G. 306 deg 073 nm
H. 993 mb
I. 16 C/ 1525 m
J. 20 C/ 1521 m
K. 18 C/ NA
L. NA
M. NA
N. 12345/ 8
O. 0.02 / 5 nm
P. AF301 0106A FLORENCE OB 14
MAX FL WIND 61 KT N QUAD 18:24:30 Z
-------
If I'm reading this correctly, the Hunter found very little in the way of strengthening, and in fact the next discussion may be forced to say it is weaker than they thought.
You read it correctly, as usual. 5pm advisory has winds at 65 mph. Although I would add, Flo at 11 am today looked well on her way to becoming a hurricane, but she hoovered in some dry air this afternoon and methinks that dropped her down a notch.
L. NA
M. NA
In other words, no sign of an eye forming.
That is a MASSIVE tropical-storm-strength windfield. And it will probably kick up some major waves in the NW Atlantic between Flo and the North American coast, especially above Hatteras.
Yes: you called that dry air thing correctly early today.
I'm going to look around at some other stuff for a while now.
Probably won't be posting again until late this evening, though.
It was named after a woman. Hellloooo!!
So even a 5pm advisory windspeed of 65 mph is a bit high. Probably should be 60 mph. Methinks they are getting a bit entrenched in their determination to make this storm fit their models.
I think the most interesting historical aspect of this storm will be the frustration it and Ernesto caused forecasters.
Statement as of 5:00 PM EDT on September 09, 2006
the initial motion estimate is 325/11. Reports from an Air Force Reserve reconnaissance aircraft indicate the low-level center of Florence is severely elongated northwest-southeast...despite the impressive satellite appearance. The recon fix positions have come in slightly to the right of the previous forecast track...so the official track remains essentially unchanged even though the NHC model consensus shifted slightly westward. The official track calls for Florence to pass over or near Bermuda between 36-48 hours.
After what appeared to be the beginning of a slight strengthening phase this morning...a subsequent recon pass through the center this afternoon indicated the central pressure had risen slightly and that the earlier developing eyewall had deteriorated. Some mid-level southeasterly shear is undercutting the impressive outflow layer...and this hindering flow pattern is not expected to abate until about 18-24 hours when Florence should be turning northward through a break in the subtropical ridge axis. Other than to slow down the intensification trend during the first 12 hours... the intensity forecast remains unchanged from the previous advisory and is lower than the GFDL...SHIPS...and FSU intensity forecasts.
Forecast positions and Max winds
initial 09/2100z 25.6n 64.3w 55 kt
12hr VT 10/0600z 26.8n 65.2w 65 kt
24hr VT 10/1800z 28.7n 65.7w 75 kt
36hr VT 11/0600z 30.8n 65.5w 85 kt...approaching Bermuda
48hr VT 11/1800z 33.3n 64.6w 90 kt...north of Bermuda
72hr VT 12/1800z 39.0n 60.0w 80 kt
96hr VT 13/1800z 45.0n 52.0w 70 kt...becoming extratropical
120hr VT 14/1800z 49.0n 43.0w 60 kt...extratropical
$$
forecaster Stewart
--------------
Four observations:
I thought it was dry air holding Flo back this afternoon, but I'll go with the shear. Since the NHC had not mentioned shear, I didn't state shear and went with the dry air argument, even though it did look on the sat photos like someone drove a D9-Cat through the SE side of the circulation this afternoon.
Second, what is with this "impressive" commentary? This storm has been anything but impressive. Methinks they are dying for this storm to become impressive so their forecasting is vindidated.
Third, look at this comment:
Some mid-level southeasterly shear is undercutting the impressive outflow layer...and this hindering flow pattern is not expected to abate until about 18-24 hours when Florence should be turning northward through a break in the subtropical ridge axis. Other than to slow down the intensification trend during the first 12 hours...
This, quite frankly, does not make sense. First of all, the shear didn't just slow down intensification - it knocked the storm down a good 10mph by the reckoning of the Hurricane Hunters, but the NHC only dropped it 5mph. Second, if the shear is to persist 18-24 hours, why would it only hold down intensification for 12 hours? And third - why the flock does the NHC keep stubbornly trying to make the storm fit its models in defiance of ground truth?
And finally, I have never been critical of the NHC before this hurricane season, and I am very hesitant to criticize them now. But they really need an attitude adjustment, IMO. They have become too damn dependent upon their models and apparently are not willing to examine realtime data in enough detail, and seem to be more bent on making realtime fit their models than on considering altering their models and forecast methods to closer fit realtime.
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