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Atlantic Tropical Action 2011 - Part II


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Higher resolution right?

LEK has described the only useful part of the NAM relative to the tropics (which is an indirect approach to the tropics). WRT track, cyclogenesis and tropical precipitation, it adds no value. If you want a more detailed presentation of how things won't work out, then yeah, the NAM is your tool.

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Because the model physics in it are tuned for continental, mid-latitude, baroclinic weather systems, not maritime, tropical, warm cored weather systems. It pools moisture in the low levels and the mid-levels are too cool, allowing for unrealistic values of conditional instability. That leads to overamplification and mostly worthless solutions. In order for a gridded (vs. spectral) model to be reasonable in the tropics, it needs to have nested grids to properly sample the inner core and allow the mass fields to stay in balance. Even then, we see how poorly the HWRF is at forecasting TCs and it uses similar physics to the NAM (though tuned to the tropics) at a better resolution with nested grids.

Thank you

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This doesn't sound like a question.

It wasn't, it was a statement. I just couldnt see the harm in looking at the nam if it's showing something simular to other numerical guidance. Obviously I was wrong, and stand corrected. That said, I will still look at the nam to see what it's showing, old habits (even if they're wrong) are hard to break.

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I wouldn't be surprised if things remain quiet until August. In fact, I'd say there is a decent chance that Bret is in fact our first Hurricane that we don't see until August.

Keep in mind, this happened in 1999, too. Arlene formed in June and we didn't see Bret until August 18th, and with that, a 125 kt Cat 4 coiled up next to Texas. Then came Cat-4 Cindy, Cat-2 Dennis, Cat-4 Floyd, Gert, Cat-2 Irene and Jose, and finally Cat-4 Lenny before the season winded down.

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Here are my latest thoughts on the Atlantic basin... I think the player to watch the next 48 hours is the tropical wave in the Atlantic. Its at a low latitude, but it currently is under a favorable upper level environment at it has at least moderate model support for continued development. Chances are it will likely run out of room before TCG can occur, but as many have been alluding to, it could help aid with something in the Caribbean down the road.

http://philstropicalweatherblog.wordpress.com/2011/07/07/tropics-becoming-more-interesting-with-two-disturbances/

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Here are my latest thoughts on the Atlantic basin... I think the player to watch the next 48 hours is the tropical wave in the Atlantic. Its at a low latitude, but it currently is under a favorable upper level environment at it has at least moderate model support for continued development. Chances are it will likely run out of room before TCG can occur, but as many have been alluding to, it could help aid with something in the Caribbean down the road.

http://philstropical...o-disturbances/

Dolly-redux, Phil? :P

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Since things are quiet, I thought some might find this fascinating. The tropical update podcasts I've done since the 2005 Season were archived and the archives from before 2007 were thought to be lost, but they were recently found in an old hard drive.

I compiled a timeline of the evolution of the wave that spawned TD-10, then the interaction between the remnants of TD-10 and the wave over the Greater Antilles which spawned TD-12 and ultimately, Hurricane Katrina.

Enjoy and comments welcome.

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Looking at the 00z ECMWF and 00z GFS, I think we need to issue a "Tropical Weather Weenie Suicide Watch" . Its going to be a rough 10-15 days...

lightning.gif

Slow time in July gives time to appreciate other things. Like the databuoy off Islip pushing 23º. 2011 is on the curve of normalcy with 1 named storm and no hurricanes until August 1st.

Happy thoughts, offshore Islip pushing 25º by meat and potatoes season in August and September.

atsst.gif

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The wave that the models were sniffing out for development in the Western Caribbean has been added this morning...

TROPICAL WEATHER OUTLOOK

NWS NATIONAL HURRICANE CENTER MIAMI FL

800 AM EDT THU JUL 7 2011

FOR THE NORTH ATLANTIC...CARIBBEAN SEA AND THE GULF OF MEXICO...

CLOUDINESS AND SHOWERS EXTENDING FROM YUCATAN ACROSS THE

SOUTHEASTERN GULF OF MEXICO...SOUTHERN FLORIDA...AND THE

NORTHWESTERN BAHAMAS ARE PRIMARILY ASSOCIATED WITH A SURFACE

TROUGH. THIS SYSTEM IS EXPECTED TO DRIFT NORTHWARD OR NORTHWESTWARD

WITH NO SIGNIFICANT DEVELOPMENT OVER THE NEXT COUPLE OF DAYS. THERE

IS A LOW CHANCE...10 PERCENT...OF THIS SYSTEM BECOMING A TROPICAL

CYCLONE DURING THE NEXT 48 HOURS.

AN AREA OF DISTURBED WEATHER ASSOCIATED WITH A TROPICAL WAVE IS

CENTERED ABOUT 600 MILES EAST-SOUTHEAST OF THE SOUTHERN WINDWARD

ISLANDS. THIS ACTIVITY IS EXPECTED TO SPREAD WESTWARD OVER NORTHERN

SOUTH AMERICA AND THE SOUTHERN WINDWARD ISLANDS DURING THE NEXT DAY

OR TWO WITH NO SIGNIFICANT DEVELOPMENT. THERE IS A LOW CHANCE...10

PERCENT...OF THIS SYSTEM BECOMING A TROPICAL CYCLONE DURING THE

NEXT 48 HOURS.

ELSEWHERE...TROPICAL CYCLONE FORMATION IS NOT EXPECTED DURING THE

NEXT 48 HOURS.

$$

FORECASTER AVILA

avn-l.jpg

post-32-0-16940400-1310041363.gif

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There goes the shuttle launch for tomorrow...

BEGIN

NHC_ATCF

invest_al962011.invest

FSTDA

R

U

040

010

0000

201107071222

NONE

NOTIFY=ATRP

END

INVEST, AL, L, , , , , 96, 2011, DB, O, 2011070706,

WHXX01 KWBC 071201
CHGHUR
TROPICAL CYCLONE GUIDANCE MESSAGE
NWS NATIONAL HURRICANE CENTER MIAMI FL
1201 UTC THU JUL 7 2011

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 (AL962011) 20110707 0600 UTC

       ...00 HRS...   ...12 HRS...   ...24 HRS. ..   ...36 HRS...
       110707  0600   110707  1800   110708  0600   110708  1800

        LAT    LON     LAT    LON     LAT    LON     LAT    LON
BAMS    24.4N  83.4W   25.6N  84.6W   26.5N  85.5W   27.7N  86.2W
BAMD    24.4N  83.4W   25.8N  83.9W   27.3N  84.4W   29.0N  84.9W
BAMM    24.4N  83.4W   25.4N  84.5W   26.4N  85.3W   27.6N  86.1W
LBAR    24.4N  83.4W   25.2N  83.8W   26.4N  84.4W   27.8N  84.7W
SHIP        20KTS          23KTS          27KTS          32KTS
DSHP        20KTS          23KTS          27KTS          32KTS

       ...48 HRS...   ...72 HRS...   ...96 HRS. ..   ..120 HRS...
       110709  0600   110710  0600   110711  0600   110712  0600

        LAT    LON     LAT    LON     LAT    LON     LAT    LON
BAMS    28.6N  86.5W   30.2N  86.7W   31.2N  87.3W   31.2N  88.6W
BAMD    30.7N  84.6W   32.1N  82.5W   31.4N  82.9W   30.1N  85.3W
BAMM    28.6N  86.4W   30.3N  87.1W   31.2N  88.4W   31.1N  90.3W
LBAR    29.2N  84.4W   32.3N  82.1W   34.9N  80.0W   37.2N  77.5W
SHIP        33KTS          37KTS          42KTS          43KTS
DSHP        33KTS          37KTS          28KTS          27KTS

        ...INITIAL CONDITIONS...
LATCUR =  24.4N LONCUR =  83.4W DIRCUR = 320DEG SPDCUR =   3KT
LATM12 =  24.0N LONM12 =  83.1W DIRM12 = 318DEG SPDM12 =   3KT
LATM24 =  23.3N LONM24 =  82.5W
WNDCUR =   20KT RMAXWD =   60NM WNDM12 =   20KT
CENPRS = 1011MB OUTPRS = 1013MB OUTRAD =  120NM SDEPTH =   S
RD34NE =    0NM RD34SE =    0NM RD34SW =    0NM RD34NW =   0NM

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RECON will take a look see tomorrow...

WEATHER RECONNAISSANCE FLIGHTS

CARCAH, NATIONAL HURRICANE CENTER, MIAMI, FL.

0915 AM EDT THU 07 JULY 2011

SUBJECT: TROPICAL CYCLONE PLAN OF THE DAY (TCPOD)

VALID 08/1100Z TO 09/1100Z JULY 2011

TCPOD NUMBER.....11-037

I. ATLANTIC REQUIREMENTS

1. SUSPECT AREA (GULF OF MEXICO)

FLIGHT ONE -- TEAL 70

A. 08/1700Z

B. AFXXX 01BBA INVEST

C. 08/1530Z

D. 28.2N 85.0W

E. 08/1630Z TO 08/2200Z

F. SFC TO 10,000 FT

FLIGHT TWO -- TEAL 71

A. 09/0600,1200Z

B. AFXXX 0202A CYCLONE

C. 09/0430Z

D. 29.4N 84.8W

E. 09/0530Z TO 09/1200Z

F. SFC TO 10,000 FT

2. OUTLOOK FOR SUCCEEDING DAY.....NEGATIVE.

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If 96L can develop, I think it'll be the first NAM win over the GFS since Edouard. Like my Houston Astros ending a 5 game losing streak.

The NAM no longer shows it developing. It is just a cluster of convection and that's it, the lowest pressure the NAM gives it is 1008mb. Even then that does not happen till it is off the NE coast.

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The NAM no longer shows it developing. It is just a cluster of convection and that's it, the lowest pressure the NAM gives it is 1008mb. Even then that does not happen till it is off the NE coast.

I guess they have to schedule recon for something that close to Florida. Maybe the shuttle launch scheduled figures in as well, but there is no reliable guidance, this is the divergence region of a cold core low, and CIMSS shear puts this under 20 to 30 knots of Southerly shear.

The wave headed for South America would be a better candidate for an invest, although it looks like land interaction puts the kabosh on that. The morning Jamaica sounding had 28 knot East winds at 850mb, even if it stayed over water, it would need to get beyond that, probably. Hard to get good convergence at the low levels (not to mention favorable shear) when the Easterlies are that strong.

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The 12Z GFS suggests a TC developing near the Yucatan/BoC. This is the strong TW that will be near the S Windward Islands on Saturday. It also appears that the wave is gaining some latitude as well this morning...

post-32-0-67136500-1310056151.gif

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The 12Z GFS suggests a TC developing near the Yucatan/BoC. This is the strong TW that will be near the S Windward Islands on Saturday. It also appears that the wave is gaining some latitude as well this morning...

Still too far out there, but looks like any moisture (let alone a cyclone) will be kept very far south for drought stricken TX... the pattern is just pretty straightforward, and unless there's a surprise s/w riding below the ridge, everything will move W to WNW through the Caribbean and GOM

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Still too far out there, but looks like any moisture (let alone a cyclone) will be kept very far south for drought stricken TX... the pattern is just pretty straightforward, and unless there's a surprise s/w riding below the ridge, everything will move W to WNW through the Caribbean and GOM

Agreed. I'm not too bullish on this one yet. There doesn't seem to be much of a trigger beyond the easterly wave.

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Agreed. I'm not too bullish on this one yet. There doesn't seem to be much of a trigger beyond the easterly wave.

Yep, agreed, only reason right now looks to be that the Euro and GFS have been trying to spin something up for several runs, plus the favorable upward motion in the western part of the basin.

Talking about Arlene 2.... the SW GOM has already "healed" from Arlene 1 in just 4 days

2011183gosst.png

2011187gosst.png

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TROPICAL WEATHER OUTLOOK

NWS NATIONAL HURRICANE CENTER MIAMI FL

200 PM EDT THU JUL 7 2011

FOR THE NORTH ATLANTIC...CARIBBEAN SEA AND THE GULF OF MEXICO...

CLOUDINESS AND SHOWERS EXTENDING FROM YUCATAN ACROSS THE EASTERN

GULF OF MEXICO...THE FLORIDA PENINSULA...AND THE NORTHWESTERN

BAHAMAS ARE PRIMARILY ASSOCIATED WITH AN ELONGATED AREA OF LOW

PRESSURE. ALTHOUGH THIS SYSTEM HAS BECOME A LITTLE BETTER ORGANIZED

DURING THE PAST SEVERAL HOURS...UPPER-LEVEL WINDS ARE EXPECTED TO

BE ONLY MARGINALLY CONDUCIVE FOR FURTHER DEVELOPMENT. THERE IS A

LOW CHANCE...20 PERCENT...OF THIS SYSTEM BECOMING A TROPICAL OR

SUBTROPICAL CYCLONE DURING THE NEXT 48 HOURS.

AN AREA OF DISTURBED WEATHER ASSOCIATED WITH A TROPICAL WAVE IS

CENTERED ABOUT 550 MILES EAST-SOUTHEAST OF THE SOUTHERN WINDWARD

ISLANDS. ALTOUGH DEVELOPMENT OF THIS SYSTEM IS NOT EXPECTED...

LOCALLY HEAVY RAINS ARE POSSIBLE OVER NORTHERN SOUTH AMERICA AND

THE SOUTHERN WINDWARD ISLANDS DURING THE NEXT DAY OR TWO. THERE IS

A LOW CHANCE...10 PERCENT...OF THIS SYSTEM BECOMING A TROPICAL

CYCLONE DURING THE NEXT 48 HOURS.

ELSEWHERE...TROPICAL CYCLONE FORMATION IS NOT EXPECTED DURING THE

NEXT 48 HOURS.

$$

FORECASTER BLAKE

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