ATL : HARVEY - Tropical Depression - Discussion

[SouthDadeFish]

https://my.sfwmd.gov/sfwmd/common/images/weather/plots/storm_93.gif
current models....

I know the above is a model from earlier but I have no clue how to post a newer model so for this purpose I will quote it.

I know we have pro mets here, mods and very knowledgeable weather followers. The question is, which of the models do you trust or believe may be more than 70% accurate?

For us that know very little about tutts, ridges and all of the good stuff you know, it would be appreciated to hear your personal opinions in layman’s terms.

Well in the Atlantic the Euro (ECMWF) usually does the best job. Actually in 2010 the Euro out performed the TVCN consensus. The TVCN consensus is usually what the NHC bases their forecast track off of. It takes into account the major global models such as the GFS, UKMET, NOGAPS, and hurricane specific models like the GFDL, and HWRF. I'm not a big fan of the UKMET and NOGAPS though. Also, you have to look at what time frame the models are talking about. Anything beyond 120 hours you shouldn't put much confidence in. The closer the time frame the more accurate they are.

Here's more information:

http://www.wunderground.com/hurricane/models.asp

[cycloneye]

30%

A BROAD LOW PRESSURE SYSTEM LOCATED ABOUT 575 MILES SOUTHWEST OF THE
SOUTHERN CAPE VERDE ISLANDS IS PRODUCING AN AREA OF DISORGANIZED
CLOUDINESS AND SHOWERS. SOME SLOW DEVELOPMENT IS POSSIBLE OVER THE
NEXT SEVERAL DAYS AS THE DISTURBANCE MOVES WESTWARD AT 15 TO 20
MPH. THIS SYSTEM HAS A MEDIUM CHANCE...30 PERCENT...OF BECOMING A
TROPICAL CYCLONE DURING THE NEXT 48 HOURS.

[underthwx]

https://my.sfwmd.gov/sfwmd/common/images/weather/plots/storm_93.gif
current models....

I know the above is a model from earlier but I have no clue how to post a newer model so for this purpose I will quote it.

I know we have pro mets here, mods and very knowledgeable weather followers. The question is, which of the models do you trust or believe may be more than 70% accurate?

For us that know very little about tutts, ridges and all of the good stuff you know, it would be appreciated to hear your personal opinions in layman’s terms.

Well in the Atlantic the Euro (ECMWF) usually does the best job. Actually in 2010 the Euro out performed the TVCN consensus. The TVCN consensus is usually what the NHC bases their forecast track off of. It takes into account the major global models such as the GFS, UKMET, NOGAPS, and hurricane specific models like the GFDL, and HWRF. I'm not a big fan of the UKMET and NOGAPS though. Also, you have to look at what time frame the models are talking about. Anything beyond 120 hours you shouldn't put much confidence in. The closer the time frame the more accurate they are.

Here's more information:

http://www.wunderground.com/hurricane/models.asp

thanks..I too have no earthly idea what all that means as well...i am saving this for my references...thanks!

[ConvergenceZone]

30%

A BROAD LOW PRESSURE SYSTEM LOCATED ABOUT 575 MILES SOUTHWEST OF THE
SOUTHERN CAPE VERDE ISLANDS IS PRODUCING AN AREA OF DISORGANIZED
CLOUDINESS AND SHOWERS. SOME SLOW DEVELOPMENT IS POSSIBLE OVER THE
NEXT SEVERAL DAYS AS THE DISTURBANCE MOVES WESTWARD AT 15 TO 20
MPH. THIS SYSTEM HAS A MEDIUM CHANCE...30 PERCENT...OF BECOMING A
TROPICAL CYCLONE DURING THE NEXT 48 HOURS.

Yea, per my earlier post today, I figured the percentage would start dropping, although I think it's in more in the 10 to 20% range rather than 30%, but perhaps they are trying to bring it down slowly.

[ROCK]

I am not concerned about the ridge. It's going to slide east and open the door to the GOM. That my friends is a fact....don't ask me when though....

[underthwx]

I am not concerned about the ridge. It's going to slide east and open the door to the GOM. That my friends is a fact....don't ask me when though....

what site can I go to look at ridges and their forecasts......by the way Im just down the road from you in Pearland, hello from West Columbia!

[cycloneye]

ASCAT made around 7:35 PM EDT. Not much there as it caught only the western side.

[knotimpaired]

I would like to say hello to all 72 guests here.

I have been a member since 2005 and while you may lurk we all welcome your thoughts on what is happening. I my opinion you would not be watching if you were not interested.

Please take the time to register, it is free, and join in our conversations.

[CourierPR]

30%

A BROAD LOW PRESSURE SYSTEM LOCATED ABOUT 575 MILES SOUTHWEST OF THE
SOUTHERN CAPE VERDE ISLANDS IS PRODUCING AN AREA OF DISORGANIZED
CLOUDINESS AND SHOWERS. SOME SLOW DEVELOPMENT IS POSSIBLE OVER THE
NEXT SEVERAL DAYS AS THE DISTURBANCE MOVES WESTWARD AT 15 TO 20
MPH. THIS SYSTEM HAS A MEDIUM CHANCE...30 PERCENT...OF BECOMING A
TROPICAL CYCLONE DURING THE NEXT 48 HOURS.

Yea, per my earlier post today, I figured the percentage would start dropping, although I think it's in more in the 10 to 20% range rather than 30%, but perhaps they are trying to bring it down slowly.

Perhaps the NHC believes the percentage is 30% as stated in the outlook.

[Blown Away]

No 00z BAM models, maybe NHC is throttling back on 93L?

[cycloneye]

00z Best Track

AL, 93, 2011081300, , BEST, 0, 116N, 326W, 25, 1011, DB

ftp://ftp.tpc.ncep.noaa.gov/atcf/tcweb/ ... 011.invest

[cycloneye]

No 00z BAM models, maybe NHC is throttling back on 93L?

They came out very late,but here are the 00z models.

Code: Select all

WHXX01 KWBC 130137
CHGHUR
TROPICAL CYCLONE GUIDANCE MESSAGE
NWS NATIONAL HURRICANE CENTER MIAMI FL
0137 UTC SAT AUG 13 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 (AL932011) 20110813 0000 UTC
 
        ...00 HRS...   ...12 HRS...   ...24 HRS. ..   ...36 HRS...
        110813  0000   110813  1200   110814  0000   110814  1200
 
         LAT    LON     LAT    LON     LAT    LON     LAT    LON
BAMS    11.6N  32.6W   11.9N  34.6W   12.1N  37.3W   12.6N  40.6W
BAMD    11.6N  32.6W   11.9N  35.2W   12.2N  37.7W   12.4N  40.1W
BAMM    11.6N  32.6W   12.0N  35.0W   12.4N  37.6W   12.8N  40.5W
LBAR    11.6N  32.6W   11.8N  35.6W   12.2N  38.8W   12.7N  41.9W
SHIP        25KTS          26KTS          30KTS          36KTS
DSHP        25KTS          26KTS          30KTS          36KTS
 
        ...48 HRS...   ...72 HRS...   ...96 HRS. ..   ..120 HRS...
        110815  0000   110816  0000   110817  0000   110818  0000
 
         LAT    LON     LAT    LON     LAT    LON     LAT    LON
BAMS    13.2N  44.0W   14.3N  50.8W   16.0N  58.3W   18.3N  66.2W
BAMD    12.8N  42.2W   13.9N  45.4W   15.9N  48.0W   17.9N  50.0W
BAMM    13.4N  43.3W   14.6N  48.4W   16.3N  52.9W   17.6N  56.3W
LBAR    13.1N  44.8W   13.6N  50.3W   14.7N  54.2W   14.6N  56.1W
SHIP        43KTS          56KTS          62KTS          67KTS
DSHP        43KTS          56KTS          62KTS          67KTS
 
         ...INITIAL CONDITIONS...
LATCUR =  11.6N LONCUR =  32.6W DIRCUR = 275DEG SPDCUR =  14KT
LATM12 =  11.3N LONM12 =  30.0W DIRM12 = 272DEG SPDM12 =  15KT
LATM24 =  11.0N LONM24 =  26.5W
WNDCUR =   25KT RMAXWD =   60NM WNDM12 =   25KT
CENPRS = 1011MB OUTPRS = 1013MB OUTRAD =  200NM SDEPTH =   S
RD34NE =    0NM RD34SE =    0NM RD34SW =    0NM RD34NW =   0NM
 
$$


[Adoquín]

18.3N 66.2 W?? Hey,that is my street.

[cycloneye]

18.3N 66.2 W?? Hey,that is my street.

I also live almost at those coordinates. But this dosen't mean anything as the models change constantly.The only thing for us to do at this point is to watch the progress of the system to see what it does in the next few days.

[GCANE]

No 00z BAM models, maybe NHC is throttling back on 93L?

I wouldn't be suprised if this gets deactivated at some point and then comes back to life in the mid Carib.

Typical ups and downs of a trop wave.

[Adoquín]

18.3N 66.2 W?? Hey,that is my street.

I also live almost at those coordinates. But this dosen't mean anything as the models change constantly.The only thing for us to do at this point is to watch the progress of the system to see what it does in the next few days.

Agree. The area has not seen a hurricane for 13 years, though and the set up is so ominous for the rest of the season.. ay ay ay.

[AtlanticWind]

I dont expect a lot until this gets to about 50 west when the sea surface temps are a lot warmer.

http://www.aoml.noaa.gov/phod/dataphod1 ... 3atsst.png

[cycloneye]

00z Tropical Model tracks:

['CaneFreak]

No offense but it really isn't the SSTs that are the problem...it is still the dry air...and NO I am NOT talking about SAL...I am talking about mid level dry air...it can come from anywhere...not just Africa...check out this theta-e sounding from Dakar...it is really hard to get good development when there is 40 percent RH at 600 mb...will this EVER change? Who knows...

Low theta-e = low moisture content



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I dont expect a lot until this gets to about 50 west when the sea surface temps are a lot warmer.

http://www.aoml.noaa.gov/phod/dataphod1 ... 3atsst.png

['CaneFreak]

Models are pretty much pointless until it develops to be completely honest...and it may not make it...tons of dry air ahead of it...it may not develop until the NW Carribean if the vorticity even has any structure by then...it is going to be hard to maintain that vorticity if there are little to no thunderstorms firing around this thing due to the lack of stretching (dry air)...check back next week