11PM DISCUSSION

[dhweather]

Like I've been saying, the Tuesday model runs will be key......



WTNT41 KNHC 310301
TCDAT1
HURRICANE FRANCES DISCUSSION NUMBER 25
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
11 PM EDT MON AUG 30 2004

THE LAST REPORT FROM A NOAA RECON AIRCRAFT INDICATED THE PRESSURE
HAD DECREASED TO 945 MB. HOWEVER...SINCE THAT TIME...THE SATELLITE
SIGNATURE HAS CHANGED LITTLE OVERALL. THEREFORE...THE INTENSITY
WILL REMAIN AT 110 KT.

FRANCES REMAINS ON TRACK AND THE MOTION IS NOW 280/12. A DEEP-LAYER
SUBTROPICAL RIDGE IS EXPECTED TO STRENGTHEN WESTWARD TO THE NORTH
OF FRANCES OVER THE NEXT SEVERAL DAYS AS GASTON AND HERMINE EXIT
THE PICTURE. BEYOND 72 HOURS...THE NHC MODELS ARE IN BETTER
AGREEMENT THAT THEY HAVE BEEN IN PREVIOUS DAYS...BUT THERE IS STILL
ENOUGH MODEL DIVERGENCE TO WARRANT CONCERN FOR ALL OF FLORIDA AND
THE BAHAMAS. THE GFDL...NOGAPS...AND TO A LESSER DEGREE....THE
GFS...MODELS BEND THE TRACK FRANCES SLIGHTLY MORE NORTHWESTWARD
AFTER 72 HOURS TOWARD NORTHEAST FLORIDA AND GEORGIA. THE UKMET...
CANADIAN...ECMWF...AND THE LATEST ETA MODEL RUN KEEP FRANCES ON A
MORE WESTWARD TRACK TOWARD SOUTH FLORIDA. GIVEN THE LONG RANGE
UNCERTAINTY IN THE EVOLUTION OF THE TROUGH-RIDGE PATTERN FORECAST
TO DEVELOP OVER THE CENTRAL AND EASTERN U.S...THE OFFICIAL FORECAST
TRACK REMAINS CLOSE TO THE PREVIOUS TRACK AND NEAR THE NHC MODEL
CONSENSUS. HOWEVER...WITH SUCH A LARGE TROUGH FORCAST TO DEVELOP
OVER THE CENTRAL U.S...IT WOULD NOT SURPRISE ME IF SUBSEQUENT MODEL
RUNS DO NOT BEGIN TRENDING A LITTLE MORE WESTWARD. THE NEW 00Z
MODEL RUNS SHOULD BE INTERESTING.

THE SHIPS INTENSITY MODEL BRINGS FRANCES UP TO 130 KT IN 48 HOURS...
WHICH SEEMS QUITE REASONABLE. HOWEVER...TIMING INNER-CORE
FLUCTUATIONS LIKE WE HAVE SEEN THE PAST DAY OR SO IS IMPOSSIBLE...
SO ONLY SLOW STEADY INTENSIFICATION IS INDICATED.


FORECASTER STEWART

FORECAST POSITIONS AND MAX WINDS

INITIAL 31/0300Z 19.7N 61.4W 110 KT
12HR VT 31/1200Z 20.1N 63.4W 115 KT
24HR VT 01/0000Z 20.9N 66.3W 115 KT
36HR VT 01/1200Z 21.8N 69.1W 120 KT
48HR VT 02/0000Z 23.0N 71.9W 120 KT
72HR VT 03/0000Z 24.7N 75.3W 120 KT
96HR VT 04/0000Z 26.5N 78.0W 120 KT
120HR VT 05/0000Z 28.0N 81.0W 100 KT...INLAND

[mobilebay]

Someone help me. I thought that if a trough was coming down that the storm would turn more north not west. however, the NHC clearly states that it thinks the models will tend more westerly. Someone please explain this.

[dhweather]

That is a good question - typically when a trough
develops, the flow increases from SW to NE.
However, the trough may be charging into a
strong subtropical high.

Where's AFM when you need him?

[tallywx]

If a trough dips down in the central plains, obviously the flow will be SW---> NE out ahead of the trough. Digging troughs are surrounded by high pressure systems on both sides. Therefore, when a trough digs deeper, it creates winds that feed into a high pressure area (the SW-NE winds actually contribute to the NW side of a clockwise-rotating high pressure area). The stronger the trough, the more it pumps the ridge to the east. Therefore, a trough far enough west digging in the central Plains pumps a ridge north of Frances, forcing her further west.

[Sean in New Orleans]

These are the first comments, I recall, laying the options open that S. Florida is not out of the woods by the NHC. This is very interesting....I would not be surprised one bit to see a track adjustment by the NHC tomorrow AM.

[opera ghost]

IT WOULD NOT SURPRISE ME IF SUBSEQUENT MODEL
RUNS DO NOT BEGIN TRENDING A LITTLE MORE WESTWARD.

Double negatives... oh how I loathe thee....

What this sentance says, grammatically, is: It would surprise me if subsequent model runs begin trending a little more westward.

Now the million dollar question is: Intentional or accidental double negatives?

[dhweather]

They're to freaked out to notice!

NHC conversation "dude, were gonna get hammered by Frances"

"oh @#$@#$"

[mobilebay]

IT WOULD NOT SURPRISE ME IF SUBSEQUENT MODEL
RUNS DO NOT BEGIN TRENDING A LITTLE MORE WESTWARD.

Double negatives... oh how I loathe thee....

What this sentance says, grammatically, is: It would surprise me if subsequent model runs begin trending a little more westward.

Now the million dollar question is: Intentional or accidental double negatives?

Great catch. However, I think that was accidental. The NHC is not trying to trick people..

[BensonTCwatcher]

I thought I was the only one to notice that! I guess the pros can discern the meaning from the model but I can't. I'd guess is a more northerly shift? GFDL?? Just when I was thinking west.....

[Air Force Met]

IT WOULD NOT SURPRISE ME IF SUBSEQUENT MODEL
RUNS DO NOT BEGIN TRENDING A LITTLE MORE WESTWARD.

Double negatives... oh how I loathe thee....

What this sentance says, grammatically, is: It would surprise me if subsequent model runs begin trending a little more westward.

Now the million dollar question is: Intentional or accidental double negatives?

Let me tell you from personal experience...just because a person has a doctorate...doesn't mean they have good grammer skills....or can spell. You ought to read the stuff I write when I don't have my spellchecker. It's aweful. Thank the good Lord my wife is my editor...and she's a grammer queen.

[BensonTCwatcher]

Yup...I am educated beyond my intelligence...so AFM, what thw heck dicussion saying, other than what we know...wait another 24 hrs and verify.

[Air Force Met]

Yup...I am educated beyond my intelligence...so AFM, what thw heck dicussion saying, other than what we know...wait another 24 hrs and verify.

That is a VERY good way of putting it...I sometimes feel that way too ..ok...alot (sic).
Yes...wait and verify.

[opera ghost]

I'm a writer in my spare time and half of the way to my english degree. Which only means that I twitch when bad grammer is obvious. (My spelling sucks)

To be honest if the sentance hadn't been questioned by someone else ("however, the NHC clearly states that it thinks the models will tend more westerly.")... I probably never would have seen it. I think it was accidental *laughs*

Back OT though- I can see a westward trend depending on what the models crank out- the further west... the more nervous it makes me to see something in the gulf.

[BensonTCwatcher]

I will.. I'll also watch the posts, I think you guys are correct about Tuesdays runs. I'll also bet that we see someting significant to steer this one on Wed. I base that on history not models.. Keep up the good work

[weatherFrEaK]

grammar </spellcheck>

[opera ghost]

*pffft* I don't believe in spell check. (and I use the quick reply feature that doesn't have spell check available)