ATL HANNA: Extratropical - Discussion

[KWT]

Does look like its undergoing some strengthening right now, not sure how strong it will bbe but its convection is sort of wrapping around the center.

Also I like the long term track, could provide some windy gales and rain here in the UK eventually.

[cpdaman]

south beach park (5 inches) i can literally hit a 3 wood there from my APt.

and i would urge anyone boating in central palm beach county to not even think about going north of lake worth. the fort pierce bouy is running higher than i have ever seen it and that usually equates to about 10-12 foot breaking waves north of west palm beach. the angle of the swell ENE means that areas south of west palm will be blocked by the bahamas' which could catch boaters further south by much surprise should they sail north out of the "bahamas shadow".

Hanna is looking good and i will return in the nite/evening to see what she has in store for the carolina's . One obseravation is that she appears to have hit a wall, i.e she was going WNW for a while and now she appears to have high tailed it nearly due N.

[coriolis]

That looks like seven landfalls: S.Carolina, Delmarva peninsula, south Jersey, long island, Rhode Island, Nova Scotia, and Newfoundland

Not a prediction.

[BigA]

The buoy 120 miles east of Cape Canaveral is reporting a pressure of 979.7 millibars, for what it's worth. Winds are still blowing at 16kts, so if it is accurate, there might be a bit lower pressure in the exact center.

[RevDodd]

[/quote]

That looks like seven landfalls: S.Carolina, Delmarva peninsula, south Jersey, long island, Rhode Island, Nova Scotia, and Newfoundland

Not a prediction.[/quote]

Could make it 8 if Hanna crosses Cape Romain below Georgetown, then slips ashore just south of Myrtle Beach.

[cpdaman]

latest recon shows alot of East and SE winds and a strong SE side (less winds of NE angle than last obs from late nite)

lots of water may pile up to the right of where this landfalls (as usual)

[NEXRAD]

On long range radar imagery (KMLB/KJAX), Hanna displays deeper convection clustered close to the storm's circulation center, although at such radar ranges this sampling is more mid-level than surface. IRWV shows Hanna as becoming convectively deformed over the past few hours, with the core cluster now oriented along a SW to NE axis. Cloud-tops have warmed slightly, but the IR frames show that the rain/storm activity close to the tropical storm's center remains reasonably well organized. Visible imagery reveals that low-level banding has improved markedly since about 14Z, and there are several low-cloud bands that are well organized to Hanna's east. A convectively-active band is noticeable in Hanna's NW quadrant. Outflow looks fair, with the best signatures seen to Hanna's SW. TS Hanna looks remarkably similar to 2005's Ophelia (when Ophelia was offshore EC Florida). The 2005 storm had perhaps better outflow, but Hanna has a slightly better convective appearance.

Given the limited shear aloft and lack of observable dry-air entrainment, Hanna seems likely to strengthen to a minimal hurricane in the short-term. Note that the actual ground difference between a 60 knot tropical storm and a 65 knot hurricane is quite minimal; the effects of a strong tropical storm or weak, minimal, hurricane are nearly the same.

- Jay

Personal Forecast Disclaimer:
The posts in this forum are NOT official forecast and should not be used as such. They are just the opinion of the poster and may or may not be backed by sound meteorological data. They are NOT endorsed by any professional institution or storm2k.org. For official information, please refer to the NHC and NWS products

[seahawkjd]

Just wanted to give some observations so far from around Emerald Isle, NC. Its been pouring off and on all day so far, the roads are starting to pond up. We've also had at least 1 spotted water spout / tornado and another doplar indicated one.

[krisj]

Breezes picked up here near Charleston. No rain yet. The local Publix was packed this morning. You'd never know by looking outside that we are expecting bad weather. It's breezy, but otherwise still okay outside.

I'm really bugged that the model site I usually go to http://my.sfwmd.gov/sfwmd/common/images ... orm_08.gif just has the big US picture. I can't really tell if the models have shift. I really have no idea of the time the weather is going to get bad and IF it will hit us or go north. I'm not thrilled that this might come through at night though. I have many big not so healthy trees in my yard. I'd like to be able to see how they are doing with the wind. It might be scary at night.

TWC just says it could be SC, it could be NC. Can't they get a little bit more accurate at this point?

[txwatcher91]

The posts in this forum are NOT official forecast and should not be used as such. They are just the opinion of the poster and may or may not be backed by sound meteorological data. They are NOT endorsed by any professional institution or storm2k.org. For official information, please refer to the NHC and NWS products.

This is not good. Hanna has an upper level anticyclone almost over her which will really allow her to intensify as shear drops to zero and outflow will really organize. I have a bad feeling that with this she may be 100mph at landfall if current trends continue.

[NEXRAD]

Regardless of whether Hanna makes landfall in SC or NC, the storm is large enough that weather conditions will deteriorate for much of Eastern South Carolina. The general time-frame based on the NHC's/TPC's track would bring Hanna's greatest impact to Eastern South Carolina this evening through early Saturday. This agrees, too, with the local NWSFO forecasts.

- Jay

[krisj]

Rain just started falling. Glad my son just took my dog out for a good run a few minutes ago when the weather was good. Wind is picking up all of a sudden.
I'd like a better idea of time when it will be really bad.
My satellite tv just went out. Guess that means the weather is starting.

[silvercutie]

hopefully hannah wont be as bad when hits here on sunday. Its gonna be rough for me i was visiting when hurricane juan hit ruined most of downtain Halifax and point pleasent park was totalled. Im back in Halifax now and not supprised with all these storms. I knew it was gonna come inventually. This year alone the weather was really off. the winter in ontario was cold we move down to Halifax and had to take our jackets and sweaters off n can wear tshirts. the spring barely had rain then the summer was a bit chilly less hot and most of the time fall like weather since mid july. I dont feel it will affect me that much since i dont live on the coast but i do know we will get alot rain wind and power outtages. But this is pretty much our fist here this season so hopefully anyone else that lives here will be prepaired.

[NEXRAD]

This is not good. Hanna has an upper level anticyclone almost over her which will really allow her to intensify as shear drops to zero and outflow will really organize. I have a bad feeling that with this she may be 100mph at landfall if current trends continue.

Hanna has only about 18 to 24 hours remaining over water, depending on landfall point. Such a rapid intensification would mean that Hanna would go from a 55-knot storm to around 90-knots in such a short period of time. That's a 35-knot intensification, which is rapid and unusual. Ideal atmospheric conditions are needed for such intensifications, for one. Also, as noted in the TPC report on 2007's Humberto, small cyclones are more likely to have rapid intensity fluctuations. Hanna, comparatively, is a large system, and is therefore less likely to rapidly change in intensity. Finally, the conditions around Hanna are not static, and the 15Z RUC/2 suggests increased southerly shear over the storm through this evening. While the conditions won't be too hostile for further development, they are hardly ideal.

All of this given, I'd be surprised to see Hanna strengthen much more than about 10-knots (bringing it to 65-knots intensity).

(These are comments, not forecasts; always remember to consult Official NHC/TPC products and those issued by your local NWSFO for decision making.)

- Jay

[CrazyC83]

Latest SFMR data supports 65 kt (hurricane) but FL winds support lower. Probably will be bumped to at least 60 kt though.

[Bane]

000
URNT15 KNHC 051703
AF300 1108A HANNA HDOB 28 20080905
165330 2916N 07815W 8428 01381 9858 +206 +000 194045 047 062 004 00
165400 2914N 07814W 8429 01384 9864 +207 +000 199053 057 065 007 00
165430 2913N 07812W 8424 01391 9871 +201 +000 202059 062 066 004 00
165500 2912N 07811W 8423 01399 9879 +197 +000 207063 064 067 004 00
165530 2911N 07810W 8420 01410 9888 +196 +000 208064 066 066 005 00
165600 2910N 07809W 8427 01408 9892 +201 +000 207065 066 063 005 00
165630 2909N 07807W 8426 01415 9894 +210 +000 206064 065 066 004 00
165700 2907N 07806W 8429 01416 9899 +209 +000 207064 064 065 003 00
165730 2906N 07805W 8427 01424 9906 +209 +000 207064 065 066 004 00
165800 2905N 07804W 8425 01432 9912 +207 +000 209065 066 065 004 00
165830 2904N 07802W 8422 01439 9916 +208 +000 214063 064 061 005 00
165900 2903N 07801W 8426 01439 9928 +196 +000 214061 063 060 006 00
165930 2901N 07800W 8423 01447 9932 +199 +000 211059 060 059 005 00
170000 2900N 07758W 8432 01440 9938 +195 +000 211058 059 059 005 00
170030 2859N 07757W 8424 01454 9941 +194 +000 209058 059 059 005 00
170100 2858N 07756W 8425 01452 9948 +188 +000 209058 059 058 005 00
170130 2857N 07754W 8427 01456 9951 +189 +000 207055 056 057 006 00
170200 2855N 07753W 8428 01457 9954 +188 +000 208055 056 057 007 00
170230 2855N 07753W 8428 01457 9955 +189 +000 209055 056 059 005 00
170300 2853N 07751W 8424 01467 9959 +189 +000 209054 054 058 005 00
$$

looks like surface winds now support hurricane strength.

[txwatcher91]

This is not good. Hanna has an upper level anticyclone almost over her which will really allow her to intensify as shear drops to zero and outflow will really organize. I have a bad feeling that with this she may be 100mph at landfall if current trends continue.

Hanna has only about 18 to 24 hours remaining over water, depending on landfall point. Such a rapid intensification would mean that Hanna would go from a 55-knot storm to around 90-knots in such a short period of time. That's a 35-knot intensification, which is rapid and unusual. Ideal atmospheric conditions are needed for such intensifications, for one. Also, as noted in the TPC report on 2007's Humberto, small cyclones are more likely to have rapid intensity fluctuations. Hanna, comparatively, is a large system, and is therefore less likely to rapidly change in intensity. Finally, the conditions around Hanna are not static, and the 15Z RUC/2 suggests increased southerly shear over the storm through this evening. While the conditions won't be too hostile for further development, they are hardly ideal.

All of this given, I'd be surprised to see Hanna strengthen much more than about 10-knots (bringing it to 65-knots intensity).

(These are comments, not forecasts; always remember to consult Official NHC/TPC products and those issued by your local NWSFO for decision making.)

- Jay

I would have to disagree with the RUC. Last night I noted the UL anticyclone moving closer to Hanna, and now it is almost over her. If it gets over her, it will likely stay with her and keep her in a favorable environment. Really, Cat 2 wouldn't be that hard, all she would have to do would be tighten up her windfield, and the winds alone would increase. Latest recon pass shows pressure may be as low as 978 extrap. That is solid Cat 1 pressure, so like I said if the windfield tightens up Cat 2 could be reached. If she keeps a large windfield however, 80-85 would be the highest she could probably do.

[NEXRAD]

CIMSS analysis shows increased shear trends over the Florida Straits. Judging from the flow, I'd expect this shear to work north. Granted, it's not as intense as what Hanna's previously experienced, but it still is not ideal conditions. Hanna will also be entering slightly cooler water temperatures.

- Jay

[txwatcher91]

CIMSS analysis shows increased shear trends over the Florida Straits. Judging from the flow, I'd expect this shear to work north. Granted, it's not as intense as what Hanna's previously experienced, but it still is not ideal conditions. Hanna will also be entering slightly cooler water temperatures.

- Jay

But if an UL anticyclone moves over that should reduce shear over Hanna but increase shear over FL, right, or am I wrong? I thought the periphery of an UL anticyclone had high shear but the center has the low shear?

Hanna is getting better organized it appears.
MAX FL TEMP 23 C, 135 / 5NM

[Lowpressure]

CIMSS analysis shows increased shear trends over the Florida Straits. Judging from the flow, I'd expect this shear to work north. Granted, it's not as intense as what Hanna's previously experienced, but it still is not ideal conditions. Hanna will also be entering slightly cooler water temperatures.

- Jay

I would not think that water temps play a large role here as she will stay over or close to the Gulf Stream from now until landfall. I would venture to guess 75kts at landfall. There are a lot of upper 60kts now at flight level.