ATL: EX-Tropical Depression FIVE - Discussion

[Air Force Met]

That's a surprise, as convection has been diminishing for 6 hours. Perhaps NHC felt that they wanted to get watches out sooner rather than later? No sense in putting them out in the middle of the night.

Yeah I'd imagine thats exactly why they've done it now instead of wait until people are heading off to sleep...

The LLC does appear to be tightening up though and the centers appear to be getting better stacked, just needs some decent convection over the actual center, not sure it'll even get that given Dianmu never really managed it and this is a carbon copy in terms of apperence thus far...

Yeah...I'm shocked. The only explanation I have is someone else came on shift.

But...looking at hi-res...the LLC is much better defined. The convection is not that great...so I imagine it is one of those "let's get out ahead of this" type of things. I think tonight is the night and I really feel when we wake up tomorrow it will be bursting some deep convection. Maybe the NHC feels that too and wants people to be aware ahead of time.

[lebron23]

TS warnings Intercoastal City LA to Destin FL

[IvanSurvivor]

What will keep TD 5 from making a landfall in MS, AL or the FL Panhandle? Are there any scenarios that would change it's current track to LA?

The stronger it gets the more northward its steering compoent will be. So it's more towards Louisiana if it's weak, but if it ramps up really quickly it will go more towards Alabama or even the FLA panhandle.

Thanks ozonepete! Appreciate the response.

[tomboudreau]

TS warnings Intercoastal City LA to Destin FL

Where are you seeing this?

[Pearl River]

000
WTNT25 KNHC 102330
TCMAT5
TROPICAL DEPRESSION FIVE SPECIAL FORECAST/ADVISORY NUMBER 1
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL052010
2330 UTC WED AUG 11 2010

CHANGES IN WATCHES AND WARNINGS WITH THIS ADVISORY...

A TROPICAL STORM WARNING HAS BEEN ISSUED FOR THE NORTHERN GULF OF
MEXICO COAST FROM DESTIN FLORIDA TO INTRACOASTAL CITY
LOUISIANA...INCLUDING LAKE PONTCHARTRAIN AND NEW ORLEANS.

[LSU2001]

LINK: http://www.nhc.noaa.gov/text/refresh/MI ... 2330.shtml


000
WTNT25 KNHC 102330
TCMAT5
TROPICAL DEPRESSION FIVE SPECIAL FORECAST/ADVISORY NUMBER 1
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL052010
2330 UTC WED AUG 11 2010

CHANGES IN WATCHES AND WARNINGS WITH THIS ADVISORY...

A TROPICAL STORM WARNING HAS BEEN ISSUED FOR THE NORTHERN GULF OF
MEXICO COAST FROM DESTIN FLORIDA TO INTRACOASTAL CITY
LOUISIANA...INCLUDING LAKE PONTCHARTRAIN AND NEW ORLEANS.

SUMMARY OF WATCHES AND WARNINGS IN EFFECT...

A TROPICAL STORM WARNING IS IN EFFECT FOR...
* DESTIN FLORIDA TO INTRACOASTAL CITY LOUISIANA...INCLUDING LAKE
PONTCHARTRAIN AND NEW ORLEANS

A TROPICAL STORM WARNING MEANS THAT TROPICAL STORM CONDITIONS ARE
EXPECTED SOMEWHERE WITHIN THE WARNING AREA WITHIN 36 HOURS.

TROPICAL DEPRESSION CENTER LOCATED NEAR 26.0N 84.1W AT 11/2330Z
POSITION ACCURATE WITHIN 60 NM

PRESENT MOVEMENT TOWARD THE NORTHWEST OR 315 DEGREES AT 5 KT

ESTIMATED MINIMUM CENTRAL PRESSURE 1007 MB
MAX SUSTAINED WINDS 30 KT WITH GUSTS TO 40 KT.
WINDS AND SEAS VARY GREATLY IN EACH QUADRANT. RADII IN NAUTICAL
MILES ARE THE LARGEST RADII EXPECTED ANYWHERE IN THAT QUADRANT.

REPEAT...CENTER LOCATED NEAR 26.0N 84.1W AT 11/2330Z
AT 10/1800Z CENTER WAS LOCATED NEAR 25.7N 83.9W

FORECAST VALID 11/0600Z 26.8N 85.1W
MAX WIND 30 KT...GUSTS 40 KT.

FORECAST VALID 11/1800Z 28.1N 87.0W
MAX WIND 35 KT...GUSTS 45 KT.
34 KT... 75NE 75SE 50SW 75NW.

FORECAST VALID 12/0600Z 29.0N 89.0W
MAX WIND 40 KT...GUSTS 50 KT.
34 KT... 75NE 75SE 50SW 75NW.

FORECAST VALID 12/1800Z 29.7N 90.6W...INLAND
MAX WIND 30 KT...GUSTS 40 KT.

FORECAST VALID 13/1800Z 31.0N 92.0W...INLAND
MAX WIND 25 KT...GUSTS 35 KT.

EXTENDED OUTLOOK. NOTE...ERRORS FOR TRACK HAVE AVERAGED NEAR 200 NM
ON DAY 4 AND 250 NM ON DAY 5...AND FOR INTENSITY NEAR 20 KT EACH DAY

OUTLOOK VALID 14/1800Z 33.0N 90.5W...POST-TROP/REMNT LOW
MAX WIND 20 KT...GUSTS 25 KT.

REQUEST FOR 3 HOURLY SHIP REPORTS WITHIN 300 MILES OF 26.0N 84.1W

NEXT ADVISORY AT 11/0300Z

$$
FORECASTER PASCH

[lebron23]

TS warnings Intercoastal City LA to Destin FL

Where are you seeing this?

The advisory

[cpdaman]

some nice t-storms poppin .....good inflow and convection developing on South and SE side of general center

startin to wrap up?

[Pearl River]

FORECAST VALID 12/0600Z 29.0N 89.0W
MAX WIND 40 KT...GUSTS 50 KT.
34 KT... 75NE 75SE 50SW 75NW.

FORECAST VALID 12/1800Z 29.7N 90.6W...INLAND
MAX WIND 30 KT...GUSTS 40 KT.

[KWT]

Can things change? Sure. But I am calling at minimum a Category One hurricane. Landfall should be from around south of Houma, LA to around Mobile. My confidence is this is and has always been high. The models have given no one any reason to discount this and i'm confident the NHC shall reflect a similar cone.

As far as what we should do here in NOLA.....honestly be weary. Overnight tonight is going to be one hell of a nail biter and i'm seeing Danielle getting plenty stronger. Currently I believe unfortunately a Cat 1/2 landfall is looking good.

Edit: The lack of convection currently is due to dry air from the rapidly moving ULL, and potentially interaction with the ULL itself. This should be a nonissue going into tonight. After that it's anyones guess what this thing can do.

Interesting thoughts and if it had some convection over the center I'd agree but I don't think its the dry air thats the issue thats causing the hole in the convection, I'm not totally sure why it is but there have been a few storms which have had this sort of presentation and never shifted it despite having much longer then 94/Td5 has...and if it can't shift its presentation then it'll be likely limited to something between 55-65kts.

We will see though, could easily burst overnight and that become a total non issue...as you say conditions are improving for this system and I see no reason why this won't strengthen right now...and I think FWIW the current weak convection near the center will slowly get filled in, so I'm on board with possibly a minimal hurricane.

[lebron23]

NW @5

[redfish1]

so is Texas pretty much out of the woods on this one?

[KWT]

FORECAST VALID 12/0600Z 29.0N 89.0W
MAX WIND 40 KT...GUSTS 50 KT.
34 KT... 75NE 75SE 50SW 75NW.

FORECAST VALID 12/1800Z 29.7N 90.6W...INLAND
MAX WIND 30 KT...GUSTS 40 KT.

The NHC hugging the global models...this could either be a good call or it'll bust within the next 12hrs...I think its a good deal too low but they can't really go any higher given nearly every model is against this one strengthening...I say stuff the models with this one!

[lebron23]

[lebron23]

so is Texas pretty much out of the woods on this one?

No. Texas is in the cone.

[Pearl River]

ZCZC MIATCDAT5 ALL
TTAA00 KNHC DDHHMM
TROPICAL DEPRESSION FIVE SPECIAL DISCUSSION NUMBER 1
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL052010
730 PM EDT TUE AUG 10 2010

AN AIR FORCE HURRICANE HUNTER PLANE HAS JUST COMPLETED ITS
RECONNAISSANCE MISSION OF THE LOW PRESSURE SYSTEM OVER THE
SOUTHEASTERN GULF OF MEXICO. THEY CONFIRMED THAT A SURFACE
CIRCULATION WAS PRESENT...AND THERE IS SUFFICIENT ORGANIZED DEEP
CONVECTION TO CLASSIFY THE SYSTEM AS A TROPICAL DEPRESSION AT THIS
TIME. SEA SURFACE TEMPERATURES ARE VERY WARM ALONG THE PROJECTED
PATH OF THE CYCLONE...BUT THE UPPER-LEVEL WIND ENVIRONMENT IS NOT
IDEAL FOR STRENGTHENING WITH INCREASING EASTERLY SHEAR OVER THE
SYSTEM AS DEPICTED BY THE GLOBAL MODELS. ONLY THE GFDL SOLUTION
SHOWS MORE THAN MODEST STRENGTHENING...BUT THAT MODEL HAS BEEN
KNOWN TO HAVE A HIGH BIAS AT TIMES. THE OFFICIAL WIND SPEED
FORECAST IS VERY CLOSE TO THE RELIABLE STATISTICAL/DYNAMICAL LGEM
INTENSITY GUIDANCE AND TO THE NUMERICAL INTENSITY CONSENSUS.

SINCE THE CENTER IS STILL A BIT BROAD...THE INITIAL MOTION...
315/05...IS MORE UNCERTAIN THAN USUAL. A MID-LEVEL RIDGE TO THE
NORTH SHOULD PRODUCE A TURN TOWARD THE WEST-NORTHWEST WITH SOME
ACCELERATION DURING THE NEXT 24 TO 36 HOURS. THE OFFICIAL TRACK
FORECAST IS VERY SIMILAR TO THE DYNAMICAL CONSENSUS.

GIVEN THAT THIS SPECIAL ADVISORY IS BEING ISSUED SO CLOSE TO THE
TIME OF THE SCHEDULED INTERMEDIATE ADVISORY...THE NEXT ADVISORY ON
THIS SYSTEM WILL BE AT 0300 UTC.

FORECAST POSITIONS AND MAX WINDS

INITIAL 11/2330Z 26.0N 84.1W 30 KT
12HR VT 11/0600Z 26.8N 85.1W 30 KT
24HR VT 11/1800Z 28.1N 87.0W 35 KT
36HR VT 12/0600Z 29.0N 89.0W 40 KT
48HR VT 12/1800Z 29.7N 90.6W 30 KT...INLAND
72HR VT 13/1800Z 31.0N 92.0W 25 KT...INLAND
96HR VT 14/1800Z 33.0N 90.5W 20 KT...POST-TROP/REMNT LOW

$$
FORECASTER PASCH/KIMBERLAIN

[brunota2003]

I personally would of gone with 45 or maybe even 50 knots...the set up is there for it to run away, but no guarantee it will. At least if it only gets to 40 knots, the forecast still only busted by 10 knots...whereas if this thing gets to 55 or 60 knots, their forecast will bust by 15 or 20 knots.

[KWT]

Note the angle of the track, if it comes in 1-2 degrees to the south then it rakes the coast rather then going inland right away...

[lebron23]

Note the angle of the track, if it comes in 1-2 degrees to the south then it rakes the coast rather then going inland right away...

I noticed that.

[CYCLONE MIKE]

so is Texas pretty much out of the woods on this one?

No. Texas is in the cone.

Agree. Although most model consensus is showing a landfall in LA, TX nor east of LA is out of the woods. This is the first cone with the first advisory and they almost always adjust them. The weakness in the high may not be as strong as currently forecast and that along with TD5 staying weaker could cause it to head more west. Just watch and wait is all that can be done rigth now.