ATL: HELENE - Post-Tropical

[Aric Dunn]

gfdl is picking up on it.



http://moe.met.fsu.edu/cgi-bin/gfdltc2. ... =Animation

[Gustywind]

Decreasing numbers...

07/1800 UTC 12.3N 31.3W TOO WEAK 92L
07/1145 UTC 12.0N 29.5W T1.0/1.0 92L

[KWT]

Can't fail to miss the decent rotation there with 92L but conditions aren't the best out there from the looks of things.

[Gustywind]

000
AXNT20 KNHC 071804 CCA
TWDAT

TROPICAL WEATHER DISCUSSION...COR
NWS NATIONAL HURRICANE CENTER MIAMI FL
205 PM EDT TUE AUG 07 2012

...TROPICAL WAVES...

AN ATLANTIC OCEAN TROPICAL WAVE IS ALONG 18N28W TO 15N29W
TO A 1009 MB LOW PRESSURE CENTER THAT IS NEAR 12N19W...IN THE
MONSOON TROUGH. CONVECTIVE PRECIPITATION...SCATTERED MODERATE
TO ISOLATED STRONG IS FROM 10N TO 15N BETWEEN 27W AND 31W...
AND FROM 10N TO 12N BETWEEN 32W AND 35W.

[Gustywind]

Anyone can post a map related to the SAL please? That will give us a better idea of the weather conditions ahead of 92L

[Tertius]

[Gustywind]

Thanks to you everbody should appreciate and envoy it.

[Extratropical94]

http://tropic.ssec.wisc.edu/real-time/sal/splitE.jpg

If 92L can eat up that tip of the SAL which is right in front of the invest, the conditions would be pretty good for the next waves, especially Pouch 13L

[cycloneye]

18z Models

Wow,SHIP up to 77kts.

Code: Select all

WHXX01 KWBC 071834
CHGHUR
TROPICAL CYCLONE GUIDANCE MESSAGE
NWS NATIONAL HURRICANE CENTER MIAMI FL
1834 UTC TUE AUG 7 2012
 
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 (AL922012) 20120807 1800 UTC
 
        ...00 HRS...   ...12 HRS...   ...24 HRS. ..   ...36 HRS...
        120807  1800   120808  0600   120808  1800   120809  0600
 
         LAT    LON     LAT    LON     LAT    LON     LAT    LON
BAMS    11.8N  31.3W   12.4N  33.7W   12.8N  36.4W   12.6N  39.3W
BAMD    11.8N  31.3W   12.5N  34.0W   13.0N  36.4W   13.1N  38.8W
BAMM    11.8N  31.3W   12.7N  33.8W   13.3N  36.2W   13.3N  38.5W
LBAR    11.8N  31.3W   12.2N  34.7W   12.8N  38.1W   13.3N  41.4W
SHIP        25KTS          29KTS          35KTS          41KTS
DSHP        25KTS          29KTS          35KTS          41KTS
 
        ...48 HRS...   ...72 HRS...   ...96 HRS. ..   ..120 HRS...
        120809  1800   120810  1800   120811  1800   120812  1800
 
         LAT    LON     LAT    LON     LAT    LON     LAT    LON
BAMS    12.2N  42.3W   11.2N  49.4W   11.3N  57.0W   12.2N  64.9W
BAMD    12.8N  41.1W   12.0N  45.5W   12.3N  49.1W   13.7N  52.3W
BAMM    13.0N  40.9W   12.1N  45.4W   11.8N  49.1W   12.5N  52.7W
LBAR    13.5N  44.5W   13.4N  50.4W   13.6N  54.6W     .0N    .0W
SHIP        47KTS          60KTS          72KTS          77KTS
DSHP        47KTS          60KTS          72KTS          77KTS
 
         ...INITIAL CONDITIONS...
LATCUR =  11.8N LONCUR =  31.3W DIRCUR = 270DEG SPDCUR =  17KT
LATM12 =  11.8N LONM12 =  27.8W DIRM12 = 272DEG SPDM12 =  15KT
LATM24 =  11.6N LONM24 =  25.5W
WNDCUR =   25KT RMAXWD =   60NM WNDM12 =   25KT
CENPRS = 1009MB OUTPRS = 1011MB OUTRAD =  150NM SDEPTH =   S
RD34NE =    0NM RD34SE =    0NM RD34SW =    0NM RD34NW =   0NM
 


[KWT]

SHIPS certainly agressive with it, other models do very little with it at all though.

[Dean4Storms]

Strange season so far.

[cycloneye]

No wonder why SHIP has 92L going to hurricane. Is because the shear will not be a problem so the only impediment would be the dry air. 18z forecast.

Code: Select all

SHEAR (KT)        12     9     8    10    13     6     5     3     2     0     3     7     6


ftp://ftp.nhc.noaa.gov/atcf/stext/12080 ... _ships.txt

[KWT]

Looks like the lower levels are much quicker than the upper levels, sorta the same problem Ernesto had from the looks of the BAM's suite.

[blazess556]

The 12Z GFDL does take 92L down to about a 1000 mb TS with 40-50 kt winds for days 3-5.

['CaneFreak]

Mid level dry air indeed. I guess the research question becomes: why are we seeing so much mid level dry air in the tropical Atlantic? Is there something about the climatic changes we have seen in recent years that is allowing for more dry air to plague the Atlantic for longer periods than normal?

Code: Select all

700-500 MB RH     59    60    59    54    54    51    45    45    41    40    38    39    37


No wonder why SHIP has 92L going to hurricane. Is because the shear will not be a problem so the only impediment would be the dry air. 18z forecast.

Code: Select all

SHEAR (KT)        12     9     8    10    13     6     5     3     2     0     3     7     6


ftp://ftp.nhc.noaa.gov/atcf/stext/12080 ... _ships.txt

[KWT]

Decreasing numbers...

07/1800 UTC 12.3N 31.3W TOO WEAK 92L
07/1145 UTC 12.0N 29.5W T1.0/1.0 92L

I think the actual best rotation is to the south of where they are looking, somewhere around 11N.

[cycloneye]

[KWT]

A few storms flaring up on that loop there cycloneye. SAL very evident to the north of it still as well.

[TheBurn]

18:00 UTC RGB Natural Color - 92L
et tu Florence? And I really like the reflection in this shot...

[tolakram]

Floater loop

http://www.ssd.noaa.gov/PS/TROP/floater ... oater.html