Tropical Storm Bertha Model Runs

[Frank2]

By his or her posts, perhaps simeon9benjamin doesn't live in a hurricane prone area, and, doesn't realize what a westward moving system would mean for those who live in areas such as South Florida...

By the tone of several other posters, it seems they are pleased that the models all seem to go with a major weakness in the subtropical ridge - that would be Divine intervention, for sure, since it would come at just the right time...

I recall this weakness also happening during the approach of three developing systems in the same area, during the 2005 season, and, that alone prevented an even more disasterous outcome for everyone involved...

http://en.wikipedia.org/wiki/Image:2005 ... on_map.png

of course, it would be wrong to take liberties in assuming this will happen this time, so, we will see...

[wxman57]

It still looks like this supposed NW turn will have a lot to do with strength of the system. The models that want to develop this system quickly (GFS, EURO...), all want to try and take the storm out to sea, while the models that want to develop this system slowly (UKMET, CMC, NOGAPS...), al tend to take the storm further west. It still looks like it will be a few more days before we really know what will happen.

Correct, but if it doesn't develop quickly it probably won't develop at all. Upper-level winds are not as favorable for development farther west with that TUTT extending southwest to the eastern Caribbean.

[Blown Away]

It still looks like this supposed NW turn will have a lot to do with strength of the system. The models that want to develop this system quickly (GFS, EURO...), all want to try and take the storm out to sea, while the models that want to develop this system slowly (UKMET, CMC, NOGAPS...), al tend to take the storm further west. It still looks like it will be a few more days before we really know what will happen.

Correct, but if it doesn't develop quickly it probably won't develop at all. Upper-level winds are not as favorable for development farther west with that TUTT extending southwest to the eastern Caribbean.

At what point would the system be deep enough to be influenced towards the NW. Does TD status keep the system shallow enough to go W?

[Scott_inVA]

Think you're correct with the TUTT. This is somewhat reflected in all the 12Z runs.

FREEBIE model map



TCFA remains Invest 92L but Navy is bouncing between Invest and NONAME 02.
12Z still at 25Kts with a fair amount of shear. Maybe at 2PM but not enthusiastic.

Scott
Mid-Atlantic WX.com
http://www.midatlanticwx.com

[cycloneye]

Hey Scott,welcome back to the tracking thing again.

[KWT]

Good map Scott is there anyway you can zoom that in just a little to see the indivdual tracks a little better?

Does seem to be a WNW track out till about 45W then hints of a more Nw/NNW track after that.

12z GFS still taking similar track as before and also still getting fairly strong as well again:

http://www.nco.ncep.noaa.gov/pmb/nwprod ... n_144l.gif

[Ed Mahmoud]

12Z GFS recurves it, but then stalls it, with a hint of WSW movement between between hour 168 and 180. Don't know what it does beyond that, but due to 180 hour resolution lobotomy of GFS, I wouldn't put much faith into it.

[cycloneye]

The Canadian has a hurricane moving WNW to NW at the end of run.The CMC is much closer to Bermuda than GFS.

12z CMC

[Eyewall]

So TD or not what is it.

[Ed Mahmoud]

It is turning NW as mentioned above on Canadian, but 500 mb weakness it was turning towards already passing future storm 92L by to the Northeast. If one assumed the Canadian was correct (yes, I know), it would probably start bending back to the West.


However, it should be far enough North to easily be turned safely East of the US by the next trough moving offshore at 144 hours.

[Scott_inVA]

Good map Scott is there anyway you can zoom that in just a little to see the indivdual tracks a little better?

Does seem to be a WNW track out till about 45W then hints of a more Nw/NNW track after that.

12z GFS still taking similar track as before and also still getting fairly strong as well again:

http://www.nco.ncep.noaa.gov/pmb/nwprod ... n_144l.gif

KWT,

Yes, every model generates its own page, with zoom-in. 3 years ago I had to begin charging to keep the web site solvent and ad-free...but hey...it's just 15 bucks (23 if you want text messaging) for Atlantic and EPAC all season! http://www.midatlanticwx.com/modelmap.htm [/end of shameless pitch]

Shear is progged to be marginal while a more northerly component is likely.

Scott

[cycloneye]

12z GFDL:


WHXX04 KWBC 021732
CHGQLM
ATTENTION...NATIONAL HURRICANE CENTER

NCEP COUPLED GFDL HURRICANE MODEL FORECAST MADE FOR

TROPICAL DEPRESSION INVEST 92L

INITIAL TIME 12Z JUL 2

DISCLAIMER ... THIS INFORMATION IS PROVIDED AS GUIDANCE. IT
REQUIRES INTERPRETATION BY HURRICANE SPECIALISTS AND SHOULD
NOT BE CONSIDERED AS A FINAL PRODUCT. PLEASE SEE THE TPC/NHC
OFFICIAL FORECAST.


FORECAST STORM POSITION

HOUR LATITUDE LONGITUDE HEADING/SPEED(KT)

0 12.1 20.4 280./ 8.9
6 12.1 20.9 272./ 5.2
12 12.0 22.1 268./12.1
18 12.1 23.7 271./15.4
24 11.9 24.7 263./ 9.6
30 11.9 25.8 268./10.2
36 12.1 26.9 280./10.9
42 12.8 27.8 306./11.8
48 13.7 29.1 305./15.0
54 14.6 30.6 300./17.0
60 15.6 32.3 303./19.6
66 16.5 34.2 295./20.3
72 16.9 36.0 283./17.6
78 17.2 37.4 282./13.7
84 17.9 38.9 293./15.8
90 18.6 40.1 300./13.7
96 19.6 41.4 308./15.5
102 20.8 42.6 314./16.8
108 22.1 43.8 317./16.7
114 23.4 44.5 331./15.2
120 24.4 45.3 325./11.9
126 25.2 45.9 319./ 9.5

[Scott_inVA]

So TD or not what is it.

Right now it remains an Invest. Virtually every model I ingest gets this to a TD by tomorrow. The CMC kills it off while the GFS brings it to a 62Kt tropical storm next Monday. We'll see.

Scott

[cycloneye]

GFDL has it as a strong Tropical Storm but nort reaches hurricane status.

12z GFDL Animation

[cycloneye]

The 12z UKMET is the most west model for 92L so far.It reaches 20n-55w but in a weak form.

12z UKMET Animation

[cycloneye]

The 12z HWRF has it trackking as a Tropical Storm WNW,and at the end it bends NW.

12z HWRF Animation

[cycloneye]

Still not a TD.Moving west at 8kts.

785
WHXX01 KWBC 021846
CHGHUR
TROPICAL CYCLONE GUIDANCE MESSAGE
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1846 UTC WED JUL 2 2008

DISCLAIMER...NUMERICAL MODELS ARE SUBJECT TO LARGE ERRORS.
PLEASE REFER TO NHC OFFICIAL FORECASTS FOR TROPICAL CYCLONE
AND SUBTROPICAL CYCLONE INFORMATION.

ATLANTIC OBJECTIVE AIDS FOR

DISTURBANCE INVEST (AL922008) 20080702 1800 UTC

...00 HRS... ...12 HRS... ...24 HRS. .. ...36 HRS...
080702 1800 080703 0600 080703 1800 080704 0600

LAT LON LAT LON LAT LON LAT LON
BAMS 12.0N 21.0W 12.3N 24.1W 11.9N 27.5W 11.2N 30.3W
BAMD 12.0N 21.0W 12.7N 23.6W 13.3N 26.3W 13.9N 29.0W
BAMM 12.0N 21.0W 12.5N 23.8W 12.8N 26.8W 12.9N 29.7W
LBAR 12.0N 21.0W 12.2N 23.2W 12.7N 25.9W 13.3N 28.6W
SHIP 25KTS 31KTS 39KTS 49KTS
DSHP 25KTS 31KTS 39KTS 49KTS

...48 HRS... ...72 HRS... ...96 HRS. .. ..120 HRS...
080704 1800 080705 1800 080706 1800 080707 1800

LAT LON LAT LON LAT LON LAT LON
BAMS 10.9N 31.9W 15.5N 34.5W 22.7N 40.7W 27.2N 46.3W
BAMD 14.7N 31.8W 17.1N 37.9W 20.3N 43.8W 25.2N 46.1W
BAMM 13.2N 32.2W 16.3N 36.9W 21.0N 42.6W 25.8N 45.7W
LBAR 14.2N 31.7W 16.9N 37.9W 20.3N 43.6W 25.2N 45.8W
SHIP 59KTS 76KTS 82KTS 81KTS
DSHP 59KTS 76KTS 82KTS 81KTS

...INITIAL CONDITIONS...
LATCUR = 12.0N LONCUR = 21.0W DIRCUR = 280DEG SPDCUR = 8KT
LATM12 = 11.8N LONM12 = 19.5W DIRM12 = 280DEG SPDM12 = 9KT
LATM24 = 11.5N LONM24 = 17.7W
WNDCUR = 25KT RMAXWD = 60NM WNDM12 = 25KT
CENPRS = 1009MB OUTPRS = 1012MB OUTRAD = 120NM SDEPTH = M
RD34NE = 0NM RD34SE = 0NM RD34SW = 0NM RD34NW = 0NM

$$

[HURAKAN]

Luis, we're working on that. We only need a little more time!

[KWT]

very similar run to the 12z GFDL as well I notice, same sort of strength the main difference is the track is a little further west but not by much thanks to the slightly longer wait for it to turn NW, also means a little further away from the cool waters that weaken the system on the GFDL.

[Extremeweatherguy]

Looks like the same idea as yesterday. The models that strengthen the system rapidly (such as the GFS) turn it NW quickly, while the models that keep the system fairly weak (such as the UKMET) keep it on more of a W or WNW track. Which scenario eventually wins out will really have more to do with the strength of the system than anything else (IMO).