Ex-Hurricane Florence

[crimsone]

So, she has numerous centers all doing a dance around the magic roundabout I couldn't ask for more from a system called Florence

[Brrr]

Intrestingly enough we are still above average for tropical storms but now below average for hurricanes though Florance will help somewhat to put us closer to average again.

What do you think of this article Kold in regards your comment above? (I did post it elsewhere... but probably as relevant here....)

Hostile Conditions are hindering hurricanes

http://www.al.com/news/mobileregister/inde....xml&coll=3

Belinda

Edited September 5, 2006 by Brrr

[Paranoid]

GFDL bring this up to cat-3 or 4, depending on the difference between ground level and flight level, at either 116mph or 132mph. Flight level winds just exceeded category 5 at 136kts.

[Gray-Wolf]

I don't believe that we're going to have another 'Evil Twin' to deal with!!! The vis. sat. shows some nice banding to Florence and ,just now, a big burst of convection to the north but down to the SE the mass of cloud that was initially to the rear has seemed to 'catch up' with Flo. This will be the second system that Florence has 'ingested' so I hope she has a good belch afterwards!. If the models are calling for a slow down over the next few days then the atlantic will start to pile up behind her and with it any system that has formed coming off Africa.

Edited September 5, 2006 by Gray-Wolf

[Paranoid]

What do you mean by "another evil twin"? Which was the other one?

[Brrr]

What do you mean by "another evil twin"? Which was the other one?

GW is talking about Ernesto.. he had a bit of a twin by his side.. didn't come to much though!.

Belinda

[Gray-Wolf]

What do you mean by "another evil twin"? Which was the other one?

Sorry paranoid I was refering to Enesto's alter ego that he finally ended up leaving in Cuba

Florence seems to already have a few 'Pals' (according to the NHC) with her centre between two 'lesser vortices' and the larger circulation off to her SE.

EDIT: Thanks Belinda!, 'T' time madness with the kids got me mid-post (very painful)

Edited September 5, 2006 by Gray-Wolf

[kold weather]

As I can't be bothered to make one of those large posts about track of Florance, I'll just show the models instead:

worth noting though that some of the models could well be underplaying the ridge somewhat, I wouldn't be at ALL suprised to see the track slowly but surely adjust westwards, as all model guidance bar the UKMO is to the north of the present track. Therefore its logical to suggestthat the models will probably keep slowly adjusting westward for a little while yet...though whether it'll get even close to being westward enough to inpact the USA rmeians to be seen. As I said on the firs tpage of this thread, I suspect florance will curve away but to the west of Bermuda this time probably, prehaps getting close to Nova Soctia based on some of those models!

At the very least this long-range system should well boost the ACE for this season, prehaps doubling it.

Edited September 5, 2006 by kold weather

[summer blizzard]

I must admit, i am not entirely convinced about the track of this system and would still not rule out landfall in Florida, it would not take much for the GDFL to be forecasting such a landfall.

000

WTNT41 KNHC 051439

TCDAT1

TROPICAL STORM FLORENCE DISCUSSION NUMBER 8

NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL062006

1100 AM EDT TUE SEP 05 2006

CONVENTIONAL AND MICROWAVE SATELLITE IMAGERY INDICATE THAT TD-6 HAS

CONTINUED TO BECOME BETTER ORGANIZED AND HAS INTENSIFIED INTO VERY

LARGE TROPICAL STORM FLORENCE. THE INITIAL INTENSITY OF 35 KT IS

BASED ON WIND DATA FROM 05/0836Z QUIKSCAT AND 05/1002 SSMI

OVERPASSES THAT REVEALED LARGE PATCHES OF 30-35 KT UNCONTAMINATED

WINDS IN THE NORTHWEST QUADRANT. IT COULD BE ARGUED THAT STRONGER

WINDS EXIST IN THE NORTHEAST QUADRANT...BUT THAT ASSESSMENT CAN

WAIT UNTIL THE NEXT ADVISORY PACKAGE TO SEE IF CONVECTION PERSISTS.

THE INITIAL MOTION ESTIMATE IS 290/11. THE AFOREMENTIONED QUIKSCAT

OVERPASS AND ALSO ONE AT 04/2130Z NOW CLEARLY INDICATE THAT THE

BROAD CIRCULATION CENTER IS FARTHER SOUTH BY AT LEAST 40 NMI THAN

INDICATED IN PREVIOUS ADVISORIES. THE ADVISORY POSITION IS ROUGHLY

MIDWAY BETWEEN TWO SMALLER CIRCULATIONS -- ONE IN THE NORTHWESTERN

QUADRANT AND ONE IN THE SOUTHEASTERN QUADRANT THAT PASSED BY NOAA

BUOY 41041 EARLIER THIS MORNING. OTHER THAN RELOCATING THE CENTER

FARTHER TO THE SOUTH...THE FORECAST REASONING REMAINS UNCHANGED

FROM THE PREVIOUS SEVERAL ADVISORIES. THE NEW FORECAST TRACK IS

ALONG THE EXTREME SOUTHERN EDGE OF THE NHC MODEL GUIDANCE ENVELOPE

...WHICH IS MAINLY TO ACCOUNT FOR THE MORE SOUTHERLY INITIAL

POSITION. THE LARGE SUBTROPICAL RIDGE TO THE NORTH THAT WILL BE THE

MAIN STEERING MECHANISM FOR THE NEXT 4-5 DAYS IS EXPECTED TO KEEP

FLORENCE MOVING IN A WEST-NORTHWESTWARD DIRECTION. BY DAY 5...ALL

OF THE GLOBAL MODELS CONTINUE TO INSIST THAT A WEAK SHORTWAVE

TROUGH WILL BEGIN TO ERODE THE RIDGE TO NORTH OF FLORENCE AND ALLOW

THE SYSTEM TO TURN TOWARD THE NORTHWEST AND INTO THE WEAKNESS. THE

VERDICT IS STILL OUT ON THE SCENARIO GIVEN THE RELATIVE WEAKNESS OF

THE SHORTWAVE TROUGH INDICATED IN THE MODEL WIND FIELDS.

SINCE FLORENCE HAS A RATHER LARGE WIND FIELD THAT IS AT LEAST 400

NMI IN DIAMETER ALONG WITH A RADIUS OF MAXIMUM WINDS OF 90-100

NMI...ONLY SLOW INTENSIFICATION IS EXPECTED FOR THE NEXT 48-72

HOURS. AFTER THAT...THE INNER CORE WIND FIELD IS EXPECTED TO

CONTRACT IN THE PRESENCE OF LOWER VERTICAL WIND SHEAR AND OVER 29C

SSTS...WHICH SHOULD ALLOW FOR MORE SIGNIFICANT STRENGTHENING TO

OCCUR. THE ONLY REASON THAT THE INTENSITY FORECAST DOES NOT CALL

FOR FLORENCE TO BECOME A MAJOR HURRICANE BY 120 HOURS AS INDICATED

BY THE GFDL AND FSU SUPERENSEMBLE MODELS IS THE UNCERTAINTY IN

EXACTLY HOW THE UPPER-LEVEL FLOW REGIME WILL EVOLVE BY THAT TIME.

ALL OF THE MODELS INDICATE THAT FLORENCE WILL BE NEAR A NARROW 200

MB ANTICYCLONE...BUT THE EXACT POSITION OF THE CYCLONE RELATIVE TO

THAT UPPER-LEVEL RIDGE WILL BE CRITICAL IN DETERMINING JUST HOW

INTENSE FLORENCE COULD BECOME BY THAT TIME. THE INTENSITY FORECAST

REMAINS CONSERVATIVE AND IS SLIGHTLY LOWER THAN THE SHIPS MODEL.

FORECAST POSITIONS AND MAX WINDS

INITIAL 05/1500Z 17.3N 47.3W 35 KT

12HR VT 06/0000Z 17.9N 48.9W 40 KT

24HR VT 06/1200Z 18.6N 50.9W 45 KT

36HR VT 07/0000Z 19.3N 53.0W 50 KT

48HR VT 07/1200Z 20.1N 55.3W 55 KT

72HR VT 08/1200Z 21.6N 59.5W 65 KT

96HR VT 09/1200Z 23.3N 63.8W 75 KT

120HR VT 10/1200Z 25.5N 67.5W 85 KT

$$

FORECASTER STEWART

Edited September 5, 2006 by summer blizzard

[Hurricane Debby]

UPDATED: 3:05 pm EDT, September 5, 2006

THINGS ARE STARTING TO GET QUITE BUSY IN THE ATLANTIC

I think we all knew that we could not sail through this season without some kind of major development in the Atlantic. Even though the overall numbers will be way down from last season, almost near "normal" levels, that does not mean anyone is off the hook. Today we have newly named TS Florence in the central Atlantic and a new depression in the making. For now, it looks as though Florence has a decent shot at missing the U.S. East Coast although Bermuda and our friends in the Canadian Maritimes should keep close tabs on the future track. Now don't get me wrong, we are looking at more than a week from now until Florence would be a threat to land areas, if at all. A lot can change between now and then and if Florence misses its opportunity to catch a ride on the sweeping Atlantic trough, then we could have some concerns along the East Coast. I believe though that the models have a fairly solid handle on the steering patterns but we will certainly keep a close watch on Florence as it is forecast to be a strong hurricane several days from now.

Eslewhere, there is a strong tropical wave with a low pressure center located near 14.5N and 34W that shows every sign of becoming our next tropical depression. It is forecast by the models to move on off to the west, and perhaps even south of west, for the next five days or so. I will be keeping a close eye on this system as it just might get far enough to the west to raise a few eyebrows a week from now. So far, it is only a developing tropical wave and we have loads of time to monitor its progress. The rest of the Basin is free and clear of any trouble and this is especially good news for people along the battered Gulf Coast. As it looks now, there will be no tropical storms or hurricanes to deal with anytime soon in the Gulf of Mexico. Let's hope it stays that way. I will post much more here later tonight.

Courtesy Hurricane Track

[Gray-Wolf]

'tis very early doors to be calling tracks right now.As we see year upon year 'things change' when we're this far out in the Atlantic (well into FI forcasting range and we can rarely rely on those for more than trends now can we?). We need to wait until we're a lot closer before we can really have a go at landfalls.

At the moment it looks like N.C. thru N.Y. and all stations in between

EDIT: Just a question for the more 'attuned'. How far apart would two cat , say 2, Hurricanes need to be to stand a chance of forming? and if 2 storms form of equal potency would they then 'rotate around each other and if so could this movement help 'fling' one of them out of steering currents if enough of a tug was given?

EDIT:EDIT and if 3 storms formed, 1 central Cat3 storm and 2 peripheral storms......

Edited September 5, 2006 by Gray-Wolf

[crimsone]

Looking at the model predictions for both Florence and the other invest in the area following behind it, it seems plausible that these two systems could interact, perhaps even with some of that wonderful fujiwara effect if the bothe get close enough (I'm thinking of Florences projected slowdown here). The other thing I'm wondering is whether Florence may suck enough heat from the water to adversely affect the as yet undeveloped (but longstanding) invest?

[kold weather]

I covered this a little in the other thread just now Crimsone, quite complicated!

GW, I'd guess it would depend much on just how large both storms were, a safe distance i'd guess would be 500 miles, as for your second question, I haven't a clue, not sure if thats ever happened before though you do see Barolinic storms do that sort of thing from time to time.

Track is becoming easier to find out right now, with the center finally starting to tighten up and beocme noteable on sat imagery, track looks for now to be just north of west, probably close to WNW.

Also intresting to note that convection is starting to flare-up more and more closer to that low level center, worth watching to see if thats a trend overnight because it *could* be a sign that the shear is starting to ease off a little. Also worth noting that the SHIP models now have Florance at 40kts, so NHC are going to up the winds slightly for the next advisory, not suprising given the increase of convection near the center of the system. Short term shouldn't see massive amount of strengthening but the LLC is beocming nicely shaped right now and is large as well and steady, once the shear dies away I see no reason why this storm can't go on to become a full fledge hurricane eventually just like the SHIPS and GFDL are all predicting, quite possibly a major hurricane as well.

[Brrr]

FAO: Kold Weather

As the resident 'hurricane' expert....is the report headline "A developing El Nino event -- abnormal warming of the eastern tropical Pacific Ocean -- may be partially to blame (or thank) for the relatively quiet season so far. " true ? Or is this just paper hogwash? (see earlier link in my previous post if you will)

I am well aware I don't know a lot about the weather in this department , but I do keep trying.... and I guess as you didn't acknowledge my last post, you may not appreciate questions from ignoramus like myself in this dept.. but I hope I'm slowly learning (I am not full time)... but I really would appreciate reply!

Thanks in advance if you do reply

Belinda

Edited September 5, 2006 by Brrr

[John Cox]

Hi Belinda,

I never noticed I had a fellow (female) nw member close to me in Dublin.

Im sure Kold will reply in due course

[summer blizzard]

000

WTNT41 KNHC 052030

TCDAT1

TROPICAL STORM FLORENCE DISCUSSION NUMBER 9

NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL062006

500 PM EDT TUE SEP 05 2006

THE LOW-LEVEL CIRCULATION CENTER...AS WELL AS CONVECTIVE BANDING

FEATURES HAS BECOME BETTER DEFINED IN VISIBLE SATELLITE IMAGERY.

THUNDERSTORM ACTIVITY HAS ALSO BEGUN TO DEVELOP IN THE INNER CORE

REGION. GIVEN THE OVERALL IMPROVEMENT IN THE CONVECTIVE STRUCTURE

OF FLORENCE...PLUS A 05/1641Z UW-CIMSS AMSU ESTIMATE OF 1003 MB AND

42 KT...THE INITIAL INTENSITY HAS BEEN INCREASED TO 40 KT.

THE INITIAL MOTION ESTIMATE IS 290/10. ALL OF THE GLOBAL AND

REGIONAL MODELS CONTINUE TO AGREE ON A GENERAL WEST-NORTHWESTWARD

MOTION THROUGH 96 HOURS...WITH A TURN TOWARD THE NORTHWEST INTO A

DEVELOPING WEAKNESS IN THE SUBTROPICAL RIDGE AFTER THAT. THE MODELS

HAVE BEEN VERY PERSISTENT IN DEVELOPING AN EVENTUAL BREAK IN THE

RIDGE AXIS BETWEEN 65W-75W FOR THE PAST SEVERAL RUNS. HOWEVER

...EACH RUN HAS SHIFTED THE TRACK A LITTLE FARTHER TO THE WEST.

GIVEN THAT THE MID- TO UPPER-LEVEL FLOW IS FORECAST TO BE

WEST-SOUTHWESTERLY NORTH OF THE RIDGE AXIS...AND THAT A LARGE

MID-LATITUDE TROUGH IS EXPECTED TO DIG INTO THE CENTRAL U.S. BY DAY

5...THE MODELS MAY BE OVERDOING THE AMOUNT OF SHORTWAVE ENERGY

FORECAST TO GENERATE THE WEAKNESS IN THE RIDGE. THE OFFICIAL

FORECAST TRACK IS JUST AN UPDATE OF THE PREVIOUS TRACK...AND

REMAINS A LITTLE SOUTH OF THE MODEL CONSENSUS AND ALONG THE

SOUTHERN PORTION OF THE NHC MODEL GUIDANCE ENVELOPE.

ALTHOUGH FLORENCE CONTINUES TO GET BETTER ORGANIZED...IT REMAINS AN

UNUSUALLY LARGE ATLANTIC TROPICAL STORM...AND LARGE CYCLONES TEND

TO TAKE LONGER TO DEVELOP AND INTENSIFY THAN SMALLER ONES DO. AS A

RESULT...ONLY MODEST INTENSIFICATION IS FORECAST FOR THE NEXT 48

HOURS OR SO...WITH A FASTER RATE OF STRENGTHENING INDICATED AFTER

THAT AS FLORENCE MOVES OVER 29-29.5C SSTS AND BENEATH DECREASING

VERTICAL SHEAR. IF FLORENCE MOVES UNDERNEATH THE CENTER OF A 200 MB

ANTICYCLONE LIKE THE NOGAPS...UKMET...AND ECMWF MODELS ARE

SUGGESTING...THEN STRENGTHENING INTO A MAJOR HURRICANE LIKE THE

GFDL AND FSU SUPERENSEMBLE MODELS ARE FORECASTING WILL BE POSSIBLE.

FORECAST POSITIONS AND MAX WINDS

INITIAL 05/2100Z 17.4N 48.5W 40 KT

12HR VT 06/0600Z 18.0N 49.9W 45 KT

24HR VT 06/1800Z 18.8N 51.9W 50 KT

36HR VT 07/0600Z 19.7N 54.0W 55 KT

48HR VT 07/1800Z 20.6N 56.5W 60 KT

72HR VT 08/1800Z 22.3N 61.1W 70 KT

96HR VT 09/1800Z 24.3N 65.7W 80 KT

120HR VT 10/1800Z 27.0N 69.0W 90 KT

$$

FORECASTER STEWART

[crimsone]

I wish it was near some islands - that way I'd have something to compare its size to

Edit: I tell a lie. It's just in view of the Greater Antilles at the bottom left corner of the latest visible sattelite on floater 1

Edited September 6, 2006 by crimsone

[Gray-Wolf]

My ,my she's dawdling ! Florence finally seems to be drifting out of the shear so I expect we should see the convection encircle the low today (quite bare on the western side at the mo') and then she can grow up nice and balenced!!! She is very big though isn't she??(is that polite to say of a girlie or do I have to call her 'bonny' instead?)

[kold weather]

Well overnight Florance has become much better organised with a good flare-up to the east of the center though the center still is wobbling about quite a lot and is still re-locating from time to time as well which is making its present track quite hard to calculate. I'll put up the water vapor link because it shows a vital player in Florance's future, the ULL you can see clearly spinning to its west which is the system presently inflicting shear on Florance:

http://www.ssd.noaa.gov/goes/flt/t1/loop-wv.html

Models looking much better in terms of agreement now:

http://sfwmd.gov/org/omd/ops/weather/plots/storm_06.gif

This would suggest high confidence of a track that should eventually take it northwards away from the USA, to the west of Bermuda and prehaps only being a threat to newfoundland either as a tropical or extra tropical feature. Intrestingly though depsite better agreement the GFS now shows Florance missing the weakness and the ridge re-building in which would suggest at the very least Florance would get closer then you'd want it to get.

Anyway onto the strength forecast. What is currently somewhat pegging it back is the ULL to its west however looking at the WV it does seem like the ULL is moving out to the west faster then Florance which should eventually actually enhance the outflow of Florance and help to strengthen it. Not sure quite how far away we are from this but I'd guess the shear will keep on decreasing for a little while yet. However its not gone just yet as Florance is still lop-sided. Beyond this and while we still have some dry air to its SW a system the size of Florance shouldn't have too hard of a time to mix that out and keep its core unaffected. Given its size and already good structure once the shear eases that massive mass of convection should re-center and wil lnot be lop-sided. Given the models are all still making Florance a pretty powerful hurricane there is no reason to think that this will not be the case, though they are probably over-progressive as I'd guess shear won't ease quite as fast as expected. Still despite this hurricane status is quite likely in the next 4 days and quite possibly alot higher as well given the SST's are around 29C and heat content seems to suggest under perfect condtions a cat-4 is more then possible but whether the shear will allow it to get quite that strong I have my doubts but who knows, these things do what they want sometimes!

Brrr...Indeed El Nino is probably a large factor in why this season has been queit so far...though actually despite what we'd think the named storms are above average still!

people should NEVER compare any season to 2005...as it was a mammoth freak!!!

[SMU]

FAO: Kold Weather

As the resident 'hurricane' expert....is the report headline "A developing El Nino event -- abnormal warming of the eastern tropical Pacific Ocean -- may be partially to blame (or thank) for the relatively quiet season so far. " true ? Or is this just paper hogwash? (see earlier link in my previous post if you will)

I am well aware I don't know a lot about the weather in this department , but I do keep trying.... and I guess as you didn't acknowledge my last post, you may not appreciate questions from ignoramus like myself in this dept.. but I hope I'm slowly learning (I am not full time)... but I really would appreciate reply!

Thanks in advance if you do reply

Belinda

Belinda -

This is partially the reason why the Atlantic has been slow this year- With El nino assisting the formation of pacific waves, Storms & Eventual Hurricanes there is a rule of thumb to observe- Busy Pacific Quiet Atlantic-

This holds true more often than not...

The other inhibitor to the Cape Verde season is the anonmalous amount of SAL ( SAHARAN AIR LAYER )just to the North of the Storm

track-

This 'dry' air inhibits the development of tropical waves- Heres a link you may find useful to read-

http://www.publicaffairs.noaa.gov/releases...noaa04-034.html

Heres an image as its comes of the coast-

The current levels of SAl & indeed wind sheer ( Another Hurricane killer) have dropped to favourable levels in terms of Florence location which will ensure this system gets a good shot at developing-

the models are Recurving Florence away from the East coast, but as was identified with Ernesto that was initally progged to strike the Gulf states- early model guidence isnt always reliable ESPECIALY when the Centre of rotation takes a jog in an unconventinal direction-

We are already seeing Florence move in a more Westerly Vector than first progged, & with the possible interaction of the High Pressure to the North the system could WELL trend further & further West-

Expect the model guidence like the GDFL etc to 'trend' the Track West towards the Coast, the cone still stretches from North Florida all the way to NYC......cat 3 or Cat 4 depending on the observed Sheer- ( Hopefully minimal)

Best regards

S

Edited September 6, 2006 by Steve Murr

[kold weather]

Intresting post Steve. The thing here is that the models aren't always that good when it comes to picking up fairly weak shortwave troughs, like the one that is meant to pick up Florance are not easy to forecast more then 48hrs away with any decent accuracy, something that is soooooo vital in tropical track. Who knows whether the models have it right but Steve is right when it hasn't got an established center then the models can be quite unsettled.

(ps, I'd go along with cat-3/4 as well Steve, esp when it crosses the warmer waters to its WNW and heat content rises, plus its big size will help it even if it does mean rapid strengthening isn't likely.)

Edited September 6, 2006 by kold weather

[Gray-Wolf]

The vis. sat. now shows Florence on the cusp of wrapping around herself and looking more like a potential Hurricane. You can plainly see that she has finaly escaped the shear now (her northern sector is wrapping around herself and is no longer stretched out to the NE.....a fate reserved for the 'twin' to her SE) The secondary circulation (K.w.'s ULL) is indeed 'catching her up' and would look like becoming absorbed over the next day or so (almost Junovian in scale!!).As for size? I'd go along with everyone else and say big (Cat 3/4 at tops) , her track? More 'hopecast' than 'forecast' but I'd see her tracking closer to mainland U.S.(landfall???) than current tracks suggest!.

EDIT: For the past few hours her track looks due west.

Edited September 6, 2006 by Gray-Wolf

[kold weather]

I concur GW, looks like Florance current track is a little north of due west given the sat loops and I'm not quite sure where the NHC have gotten there WNW track from, though it may be the averaged track over the last 12hrs or something like that, justa guess!

Anywaygot a rare treat for you all, some of my own handiwork, ther eis where i think Florance will track, quite similar to that of the NHC but slightly further to the west to reflect the constant current westerly motion. i'll make a more indepth post maybe later on tonight. Every point is 24hrs apart

(ps, not the best of drawings, track is a little too far south for my liking ove rthe next 48hrs now being able to look at the whole thing.)

Edited September 6, 2006 by kold weather

[Paranoid]

How large exactly is Florence, and how large will she be when at higher strengths? I saw the model on GFDL and Florence was huge.

[summer blizzard]

000

WTNT41 KNHC 061442

TCDAT1

TROPICAL STORM FLORENCE DISCUSSION NUMBER 12

NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL062006

1100 AM EDT WED SEP 06 2006

VISIBLE IMAGERY THIS MORNING SHOWS A WELL-DEFINED LOW-CLOUD SWIRL

WITH SOME THIN CONVECTIVE BANDING DEVELOPING IN THE SOUTHEAST AND

NORTHWEST QUADRANTS. THE STRONGEST CONVECTION CONTINUES TO BE

LOCATED WELL TO THE NORTHEAST OF THE CENTER. SHIP MSJZ8 REPORTED

34 KT WINDS ABOUT 250 MILES FROM THE CENTER...BEYOND THE STRONGEST

BAND OF CONVECTION. DVORAK INTENSITY ESTIMATES WERE 45 KT FROM

TAFB AND AFWA...AND 35 KT FROM SAB. BASED ON THESE DATA...THE

ADVISORY INTENSITY IS INCREASED TO 45 KT.

THE CIRCULATION NOW APPEARS TO BE MORE CIRCULAR THAN IT WAS LAST

NIGHT...AND I AM PLACING THE OVERALL SYSTEM CENTER ONLY A LITTLE

BIT NORTHWEST OF THE CLOUD SWIRL. THE INITIAL MOTION IS 290/10.

THE KEY SYNOPTIC FEATURE IN THE SHORT TERM IS THE UPPER LOW

CENTERED ABOUT 500 MILES NORTHWEST OF FLORENCE. THIS COULD IMPART

MORE OF A NORTHWARD TRACK OVER THE NEXT DAY OR TWO...AS INDICATED

BY THE GFDL MODEL...BUT THE REMAINING GUIDANCE IS TIGHTLY CLUSTERED

ON A CONTINUED WEST-NORTHWESTWARD MOTION OVER THE NEXT THREE DAYS

AS FLORENCE MOVES TO THE SOUTH OF THE MID-LEVEL SUBTROPICAL RIDGE.

NEAR THE END OF THE FORECAST PERIOD...FLORENCE IS EXPECTED TO ROUND

THE PERIPHERY OF THE RIDGE IN ADVANCE OF A DEEP-LAYER TROUGH OVER

THE EASTERN UNITED STATES. AT THE MOMENT...MODEL GUIDANCE IS IN

EXCELLENT AGREEMENT ON A NORTHWARD TURN.

THE INTENSIFICATION OF FLORENCE IS VERY DEPENDENT ON JUST HOW IT

INTERACTS WITH THE UPPER-LOW TO ITS NORTHWEST. RIGHT NOW THE LOW

IS RESPONSIBLE FOR SOUTHWESTERLY SHEAR AND BROAD-SCALE DESCENT OVER

THE CENTER...WITH THE MORE FAVORABLE DIFLUENT FLOW LOCATED WELL TO

THE NORTHEAST. THE UPPER-LOW IS FORECAST TO RETROGRADE AND WEAKEN

OVER THE NEXT COUPLE OF DAYS...AND THIS WOULD RESULT IN A MORE

FAVORABLE PATTERN FOR STRENGTHENING. THE OFFICIAL FORECAST FOLLOWS

THIS SCENARIO WITH SLOW DEVELOPMENT OVER THE NEXT 24 HOURS AND MORE

SIGNIFICANT DEVELOPMENT AFTER THAT. THE GFDL MODEL IS SLIGHTLY

HIGHER THAN THE OFFICIAL FORECAST AND SHOWS FLORENCE AS A MAJOR

HURRICANE IN 3 TO 4 DAYS.

FORECAST POSITIONS AND MAX WINDS

INITIAL 06/1500Z 18.3N 50.9W 45 KT

12HR VT 07/0000Z 19.3N 52.5W 50 KT

24HR VT 07/1200Z 20.5N 54.5W 55 KT

36HR VT 08/0000Z 22.0N 57.0W 65 KT

48HR VT 08/1200Z 23.0N 59.5W 75 KT

72HR VT 09/1200Z 25.0N 64.0W 85 KT

96HR VT 10/1200Z 28.0N 67.0W 95 KT

120HR VT 11/1200Z 31.0N 67.0W 95 KT

$$

FORECASTER FRANKLIN

http://www.nrlmry.navy.mil/htdocs_dyn/tc_p...-506W.100pc.jpg

Edited September 6, 2006 by summer blizzard