ATL: INVEST (97L)

[Aric Dunn]

Tonight's the night ladies and gentleman..

http://www.ssd.noaa.gov/goes/east/tatl/loop-avn.html

[Aric Dunn]

on another side note.. the 00z GFS wants to develop the first wave near the Bahamas in like 4 to 5 days..

[Ed Mahmoud]

00 UTC Models Suite



GFDL nor HWRF came out at 18z.

A sign, I believe, this isn't long for the world as an invest.


It might come back in the Western Caribbean, or Pacific, if it doesn't develop at all and cruises Westward.

[Ed Mahmoud]

The vort max that develops rather quickly, and is over Florida, appears to generate from the remnant of 97L, while the one in the Gulf is the lead wave approaching the Caribbean.

I don't see two systems trying to develop that closely to each other. Not sure yet about the CMC.

[Ed Mahmoud]

9 day Canadian has 97L as a monster ocean storm passing East of the Maritime provinces, while lead wave is off the Mid-Atlantic.


Salt grain worthy...

[MWatkins]

The big story to me, anyway, is the fact that this system is not screaming along at 30 knots in the easterly trades in mid-July, as one might expect from a season with such "cold" MDR water temps.

http://www.nhc.noaa.gov/text/refresh/MI ... 0611.shtml

A forward speed of 15 to 20 knots in mid August is pretty much normal. Regardless of what happens with this wave, if conditions look like this in August, I doubt the doom and gloom forecasts of 6 named storms will verify...

MW

[Ed Mahmoud]

on another side note.. the 00z GFS wants to develop the first wave near the Bahamas in like 4 to 5 days..

Canadian ultimately develops lead wave and 97L, but not right away...

[Aric Dunn]

The big story to me, anyway, is the fact that this system is not screaming along at 30 knots in the easterly trades in mid-July, as one might expect from a season with such "cold" MDR water temps.

http://www.nhc.noaa.gov/text/refresh/MI ... 0611.shtml

A forward speed of 15 to 20 knots in mid August is pretty much normal. Regardless of what happens with this wave, if conditions look like this in August, I doubt the doom and gloom forecasts of 6 named storms will verify...

MW

doom and gloom with 6 storms?? you saying you think more is in line ?

[HURAKAN]

Next!

[cycloneye]

186
ABNT20 KNHC 181135
TWOAT
TROPICAL WEATHER OUTLOOK
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
800 AM EDT SAT JUL 18 2009

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

SHOWERS AND THUNDERSTORMS NEAR AND EXTENDING A COUPLE HUNDRED MILES
EAST OF THE LESSER ANTILLES ARE ASSOCIATED WITH A TROPICAL WAVE.
WHILE RAINFALL ASSOCIATED WITH THE WAVE MAY BE LOCALLY HEAVY AT
TIMES...UPPER LEVEL WINDS ARE NOT CURRENTLY CONDUCIVE FOR
SIGNIFICANT DEVELOPMENT OF THE SYSTEM. THERE IS A LOW CHANCE...LESS
THAN 30 PERCENT...OF THIS SYSTEM BECOMING A TROPICAL CYCLONE DURING
THE NEXT 48 HOURS.

DISORGANIZED SHOWER ACTIVITY CONTINUES IN ASSOCIATION WITH A
TROPICAL WAVE LOCATED ABOUT 1200 MILES EAST OF THE WINDWARD
ISLANDS. DEVELOPMENT...IF ANY...OF THIS SYSTEM WILL BE SLOW TO
OCCUR AS IT MOVES WESTWARD AT 15 TO 20 MPH. THERE IS A LOW
CHANCE...LESS THAN 30 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 LANDSEA/BRENNAN

[tailgater]

The big story to me, anyway, is the fact that this system is not screaming along at 30 knots in the easterly trades in mid-July, as one might expect from a season with such "cold" MDR water temps.

http://www.nhc.noaa.gov/text/refresh/MI ... 0611.shtml

A forward speed of 15 to 20 knots in mid August is pretty much normal. Regardless of what happens with this wave, if conditions look like this in August, I doubt the doom and gloom forecasts of 6 named storms will verify...

MW

Very good point, but maybe we'll have more fish storms if the trend continues?
Shear SLOWLY moving off to the north.

[Gustywind]

000
AXNT20 KNHC 181047
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
805 AM EDT SAT JUL 18 2009

TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL
AMERICA...GULF OF MEXICO...CARIBBEAN SEA...NORTHERN SECTIONS
OF SOUTH AMERICA...AND ATLANTIC OCEAN TO THE AFRICAN COAST
FROM THE EQUATOR TO 32N. THE FOLLOWING INFORMATION IS BASED
ON SATELLITE IMAGERY...METEOROLOGICAL ANALYSIS...WEATHER
OBSERVATIONS...AND RADAR.

BASED ON 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY
THROUGH 1015 UTC.

...TROPICAL WAVES...
AN ATLANTIC OCEAN TROPICAL WAVE IS ALONG 39W/40W TO THE SOUTH OF
16N MOVING WESTWARD 10 KT. THIS WAVE COINCIDES WITH A LOW LEVEL
TO MIDDLE LEVEL CYCLONIC CIRCULATION CENTER. IT IS NOT EASY TO
DETERMINE THAT ANY NEARBY PRECIPITATION REALLY JUST IS RELATED
TO THIS WAVE AND/OR TO THE ITCZ. SCATTERED MODERATE SHOWERS TO
ISOLATED STRONG THUNDERSTORMS FROM 11N TO 13N BETWEEN 42W AND
46W.
$$
MT

[cycloneye]

12 UTC Best Track

I thought it would be deactivated this morning.

AL, 97, 2009071812, , BEST, 0, 119N, 418W, 20, 1013

ftp://ftp.tpc.ncep.noaa.gov/atcf/tcweb/ ... 009.invest

[poof121]

Other than the fact that the lead wave's convection is likely shear induced, I'm surprised it's not an invest.

BTW, is it considered on topic to discuss the lead wave in here? I didn't see a topic for it.

[cycloneye]

Other than the fact that the lead wave's convection is likely shear induced, I'm surprised it's not an invest.

BTW, is it considered on topic to discuss the lead wave in here? I didn't see a topic for it.

The one thread that is getting replies about that wave is the Eastern Caribbean thread at Weather Attic forum,where those who live in the islands go there and post their observations about what is going on as the wave moves thru.If you want to chim in there and make comments,you can do so.

Link to Eastern Caribbean thread below.

Eastern Caribbean Thread

[cycloneye]

This is like proforma.

CHGHUR
TROPICAL CYCLONE GUIDANCE MESSAGE
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1212 UTC SAT JUL 18 2009

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 (AL972009) 20090718 1200 UTC

...00 HRS... ...12 HRS... ...24 HRS. .. ...36 HRS...
090718 1200 090719 0000 090719 1200 090720 0000

LAT LON LAT LON LAT LON LAT LON
BAMS 11.9N 41.8W 12.5N 45.3W 12.9N 48.8W 13.5N 52.2W
BAMD 11.9N 41.8W 12.2N 44.4W 12.4N 46.8W 12.5N 49.4W
BAMM 11.9N 41.8W 12.3N 45.0W 12.5N 48.1W 12.8N 51.0W
LBAR 11.9N 41.8W 12.1N 45.2W 12.0N 48.8W 12.1N 52.3W
SHIP 20KTS 23KTS 28KTS 34KTS
DSHP 20KTS 23KTS 28KTS 34KTS

...48 HRS... ...72 HRS... ...96 HRS. .. ..120 HRS...
090720 1200 090721 1200 090722 1200 090723 1200

LAT LON LAT LON LAT LON LAT LON
BAMS 14.2N 55.9W 17.3N 63.5W 21.1N 70.5W 24.7N 74.8W
BAMD 13.0N 51.9W 15.0N 57.2W 17.2N 63.1W 18.4N 68.8W
BAMM 13.4N 53.9W 15.7N 60.1W 19.1N 66.7W 21.6N 71.6W
LBAR 12.3N 55.8W 13.6N 62.3W .0N .0W .0N .0W
SHIP 40KTS 49KTS 52KTS 56KTS
DSHP 40KTS 49KTS 52KTS 56KTS

...INITIAL CONDITIONS...
LATCUR = 11.9N LONCUR = 41.8W DIRCUR = 275DEG SPDCUR = 18KT
LATM12 = 11.5N LONM12 = 38.0W DIRM12 = 272DEG SPDM12 = 18KT
LATM24 = 11.5N LONM24 = 34.6W
WNDCUR = 20KT RMAXWD = 40NM WNDM12 = 20KT
CENPRS = 1013MB OUTPRS = 1014MB OUTRAD = 100NM SDEPTH = S
RD34NE = 0NM RD34SE = 0NM RD34SW = 0NM RD34NW = 0NM

[poof121]

Where do you find the SHIP output that says how strong it thinks the shear is at each time step?

[cycloneye]

Where do you find the SHIP output that says how strong it thinks the shear is at each time step?

Not a pleasant trip for 97L in terms of the shear.

Code: Select all

            *   ATLANTIC SHIPS INTENSITY FORECAST       *
                    *      GOES DATA AVAILABLE                  *
                    *      OHC  DATA AVAILABLE                  *
                    *      INVEST  AL972009  07/18/09  12 UTC   *

TIME (HR)          0     6    12    18    24    36    48    60    72    84    96   108   120
V (KT) NO LAND    20    21    23    25    28    34    40    46    49    50    52    55    56
V (KT) LAND       20    21    23    25    28    34    40    46    49    50    52    55    56
V (KT) LGE mod    20    20    21    22    23    26    29    33    35    36    36    35    35

SHEAR (KT)        11    11    13    16    16     9    19    18    25    27    30    26    30
SHEAR DIR          1     6   354   353     2   336   330   312   328   333   335   333   343
SST (C)         26.6  26.6  26.8  27.1  27.4  27.5  27.6  27.9  28.2  28.7  28.9  28.6  28.4
POT. INT. (KT)   122   122   124   127   131   132   133   138   142   150   152   147   143
ADJ. POT. INT.   125   123   125   128   132   132   134   139   144   151   150   139   133
200 MB T (C)   -54.2 -54.0 -53.9 -54.2 -54.3 -54.2 -54.4 -54.3 -54.7 -54.4 -54.4 -54.1 -54.5
TH_E DEV (C)       8     9     8     9     8     9     8     9     9     9     9    11    11
700-500 MB RH     59    57    59    59    59    59    64    66    65    62    62    59    60
GFS VTEX (KT)      0  LOST  LOST  LOST  LOST  LOST  LOST  LOST  LOST  LOST  LOST  LOST  LOST
850 MB ENV VOR    32    33    42    46    49    21    20    -6   -19   -29   -40   -72   -80
200 MB DIV       -18   -39   -46   -10     6     0    23    43    20   -12    -4   -19   -21
LAND (KM)       1354  1245  1151  1055   965   854   823   613   553   253    66   117   200
LAT (DEG N)     11.9  12.1  12.3  12.4  12.5  12.8  13.4  14.5  15.7  17.4  19.1  20.6  21.6
LONG(DEG W)     41.8  43.4  45.0  46.6  48.1  51.0  53.9  56.8  60.1  63.5  66.7  69.3  71.6
STM SPEED (KT)    17    16    16    15    15    14    15    16    18    18    16    13    11
HEAT CONTENT       8    10    15    23    32    37    45    51    55    61    68    51     9

  FORECAST TRACK FROM BAMM      INITIAL HEADING/SPEED (DEG/KT):275/ 18      CX,CY: -17/  2
  T-12 MAX WIND:  20            PRESSURE OF STEERING LEVEL (MB):  659  (MEAN=624)
  GOES IR BRIGHTNESS TEMP. STD DEV.  50-200 KM RAD:  15.5 (MEAN=14.5)
  % GOES IR PIXELS WITH T < -20 C    50-200 KM RAD:  41.0 (MEAN=65.0)

                        INDIVIDUAL CONTRIBUTIONS TO INTENSITY CHANGE
                         6   12   18   24   36   48   60   72   84   96  108  120
                        ----------------------------------------------------------
  SAMPLE MEAN CHANGE     1.   2.   3.   4.   6.   8.   9.  11.  11.  12.  13.  13.
  SST POTENTIAL          0.   0.   0.   1.   5.  10.  17.  23.  28.  31.  34.  36.
  VERTICAL SHEAR MAG     1.   2.   3.   4.   5.   5.   2.   0.  -4.  -7.  -9. -11.
  VERTICAL SHEAR DIR     0.   1.   1.   2.   3.   3.   4.   4.   4.   4.   4.   5.
  PERSISTENCE            0.  -1.  -1.  -1.  -1.  -1.  -1.  -1.  -1.   0.   0.   0.
  200/250 MB TEMP.       0.   0.   0.   1.   1.   2.   2.   3.   4.   4.   5.   6.
  THETA_E EXCESS         0.   0.  -1.  -1.  -1.  -2.  -2.  -3.  -4.  -5.  -5.  -5.
  700-500 MB RH          0.   0.   0.   0.   0.  -1.  -1.  -1.  -1.  -2.  -2.  -2.
  GFS VORTEX TENDENCY    0.   0.   0.   0.  -1.  -1.  -1.  -1.  -1.  -2.  -2.  -2.
  850 MB ENV VORTICITY   0.   0.   0.   0.   0.   0.   0.   0.  -1.  -1.  -2.  -3.
  200 MB DIVERGENCE      0.  -1.  -2.  -2.  -3.  -3.  -2.  -2.  -3.  -3.  -3.  -3.
  ZONAL STORM MOTION     0.   0.   1.   2.   3.   3.   4.   5.   6.   7.   8.   8.
  STEERING LEVEL PRES    0.   0.   0.   0.   0.   0.   0.  -1.  -1.  -1.  -1.  -1.
  DAYS FROM CLIM. PEAK   0.   0.   0.   0.   0.  -1.  -1.  -1.  -1.  -1.   0.  -1.
  GOES PREDICTORS        0.  -1.  -1.  -1.  -2.  -3.  -4.  -4.  -5.  -5.  -4.  -3.
  OCEAN HEAT CONTENT     0.   0.   0.   0.   0.   0.  -1.  -1.  -1.  -1.   0.   0.
                        ----------------------------------------------------------
  TOTAL CHANGE           1.   3.   5.   8.  14.  21.  27.  29.  30.  32.  35.  36.

   ** 2009 ATLANTIC RI INDEX AL972009     INVEST 07/18/09  12 UTC **
           ( 30 KT OR MORE MAX WIND INCREASE IN NEXT 24 HR)
 
 12 HR PERSISTENCE (KT):   0.0 Range:-45.0 to  30.0 Scaled/Wgted Val:  0.6/  1.3
 850-200 MB SHEAR (KT) :  13.3 Range: 26.2 to   3.2 Scaled/Wgted Val:  0.6/  0.7
 D200 (10**7s-1)       : -21.4 Range:-21.0 to 140.0 Scaled/Wgted Val:  0.0/  0.0
 POT = MPI-VMAX (KT)   : 106.6 Range: 33.5 to 126.5 Scaled/Wgted Val:  0.8/  0.5
 850-700 MB REL HUM (%):  72.0 Range: 56.0 to  85.0 Scaled/Wgted Val:  0.6/  0.3
 % area w/pixels <-30 C:  31.0 Range: 16.0 to 100.0 Scaled/Wgted Val:  0.2/  0.0
 STD DEV OF IR BR TEMP :  15.5 Range: 30.6 to   3.2 Scaled/Wgted Val:  0.6/  0.9
 Heat content (KJ/cm2) :  17.6 Range:  0.0 to 130.0 Scaled/Wgted Val:  0.1/  0.0
 
 Prob of RI for 25 kt RI threshold=     4% is   0.3 times the sample mean(12.3%)
 Prob of RI for 30 kt RI threshold=     3% is   0.3 times the sample mean( 8.0%)
 Prob of RI for 35 kt RI threshold=     1% is   0.3 times the sample mean( 4.8%)

   ##         ANNULAR HURRICANE INDEX (AHI) AL972009     INVEST 07/18/09  12 UTC         ##
   ## STORM NOT ANNULAR, SCREENING STEP FAILED, NPASS=4 NFAIL=3                          ##
   ## AHI=  0   (AHI OF 100 IS BEST FIT TO ANN. STRUC., 1 IS MARGINAL, 0 IS NOT ANNULAR) ##
   ##     ANNULAR INDEX RAN NORMALLY

At this site you can find all the runs of SHIP.

This one (12 UTC) is the last one at the bottom.

ftp://ftp.tpc.ncep.noaa.gov/atcf/stext/

[senorpepr]

12 UTC Best Track

I thought it would be deactivated this morning.

AL, 97, 2009071812, , BEST, 0, 119N, 418W, 20, 1013

ftp://ftp.tpc.ncep.noaa.gov/atcf/tcweb/ ... 009.invest

It's common for NHC to skip a fix with poorly organized systems. They'll skill the 06Z or 18Z and then extrapolate back once they accomplish the 00Z or 12Z fix.

[Gustywind]

This is like proforma.

CHGHUR
TROPICAL CYCLONE GUIDANCE MESSAGE
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1212 UTC SAT JUL 18 2009

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 (AL972009) 20090718 1200 UTC

...00 HRS... ...12 HRS... ...24 HRS. .. ...36 HRS...
090718 1200 090719 0000 090719 1200 090720 0000

LAT LON LAT LON LAT LON LAT LON
BAMS 11.9N 41.8W 12.5N 45.3W 12.9N 48.8W 13.5N 52.2W
BAMD 11.9N 41.8W 12.2N 44.4W 12.4N 46.8W 12.5N 49.4W
BAMM 11.9N 41.8W 12.3N 45.0W 12.5N 48.1W 12.8N 51.0W
LBAR 11.9N 41.8W 12.1N 45.2W 12.0N 48.8W 12.1N 52.3W
SHIP 20KTS 23KTS 28KTS 34KTS
DSHP 20KTS 23KTS 28KTS 34KTS

...48 HRS... ...72 HRS... ...96 HRS. .. ..120 HRS...
090720 1200 090721 1200 090722 1200 090723 1200

LAT LON LAT LON LAT LON LAT LON
BAMS 14.2N 55.9W 17.3N 63.5W 21.1N 70.5W 24.7N 74.8W
BAMD 13.0N 51.9W 15.0N 57.2W 17.2N 63.1W 18.4N 68.8W
BAMM 13.4N 53.9W 15.7N 60.1W 19.1N 66.7W 21.6N 71.6W
LBAR 12.3N 55.8W 13.6N 62.3W .0N .0W .0N .0W
SHIP 40KTS 49KTS 52KTS 56KTS
DSHP 40KTS 49KTS 52KTS 56KTS

...INITIAL CONDITIONS...
LATCUR = 11.9N LONCUR = 41.8W DIRCUR = 275DEG SPDCUR = 18KT
LATM12 = 11.5N LONM12 = 38.0W DIRM12 = 272DEG SPDM12 = 18KT
LATM24 = 11.5N LONM24 = 34.6W
WNDCUR = 20KT RMAXWD = 40NM WNDM12 = 20KT
CENPRS = 1013MB OUTPRS = 1014MB OUTRAD = 100NM SDEPTH = S
RD34NE = 0NM RD34SE = 0NM RD34SW = 0NM RD34NW = 0NM

Another runs on... Guadeloupe directly impacted and by extension Puerto Rico: Cycloneye hope no more than Invest or a strong open wave.