EPAC: Tropical Depression Alma (01E)

[KWT]

Not all that surprising given the rating is now at 1.0 and it does look increasingly good in terms of organisation, it now does look like a developing tropical cyclone for the first time.
I still think it could have a problem with regards to how far east it is and I think if its going to get much stronger then a weak TS its going to have to lift out NW rather then ENE like presently.

Well on the way to being a TD though as it has improved over the last 12hrs a lot.

[HURAKAN]

If the organization continues to increase, we should expect a TCFA later today.

[HURAKAN]

28/1145 UTC 9.4N 88.6W T1.5/1.5 90E -- East Pacific Ocean

Going up!!!

[JonathanBelles]

If the organization continues to increase, we should expect a TCFA later today.

I think we are close, but not close enough to say we should have a TCFA before 5p ET, but this can change.

[cycloneye]

WHXX01 KMIA 281240
CHGE77
TROPICAL CYCLONE GUIDANCE MESSAGE
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1240 UTC WED MAY 28 2008

DISCLAIMER...NUMERICAL MODELS ARE SUBJECT TO LARGE ERRORS.
PLEASE REFER TO NHC OFFICIAL FORECASTS FOR TROPICAL CYCLONE
AND SUBTROPICAL CYCLONE INFORMATION.

EAST PACIFIC OBJECTIVE AIDS FOR

DISTURBANCE INVEST (EP902008) 20080528 1200 UTC

...00 HRS... ...12 HRS... ...24 HRS. .. ...36 HRS...
080528 1200 080529 0000 080529 1200 080530 0000

LAT LON LAT LON LAT LON LAT LON
BAMS 10.0N 88.0W 10.5N 88.2W 11.0N 88.4W 11.7N 88.5W
BAMD 10.0N 88.0W 10.8N 88.0W 11.7N 88.6W 12.8N 90.0W
BAMM 10.0N 88.0W 10.6N 87.9W 11.2N 88.0W 12.1N 88.5W
LBAR 10.0N 88.0W 11.0N 87.9W 12.9N 88.5W 15.3N 89.6W
SHIP 25KTS 28KTS 32KTS 38KTS
DSHP 25KTS 28KTS 32KTS 38KTS

...48 HRS... ...72 HRS... ...96 HRS. .. ..120 HRS...
080530 1200 080531 1200 080601 1200 080602 1200

LAT LON LAT LON LAT LON LAT LON
BAMS 12.3N 88.6W 14.1N 89.2W 15.8N 90.9W 16.6N 93.4W
BAMD 13.6N 91.7W 13.9N 95.4W 12.6N 98.7W 11.6N 101.6W
BAMM 12.8N 89.1W 13.8N 90.7W 14.2N 92.4W 14.3N 94.7W
LBAR 17.7N 91.0W 20.5N 93.0W 21.1N 94.0W 20.6N 96.3W
SHIP 44KTS 52KTS 58KTS 64KTS
DSHP 44KTS 52KTS 49KTS 55KTS

...INITIAL CONDITIONS...
LATCUR = 10.0N LONCUR = 88.0W DIRCUR = 65DEG SPDCUR = 4KT
LATM12 = 9.3N LONM12 = 89.0W DIRM12 = 73DEG SPDM12 = 5KT
LATM24 = 9.7N LONM24 = 89.8W
WNDCUR = 25KT RMAXWD = 150NM WNDM12 = 25KT
CENPRS = 1006MB OUTPRS = 1009MB OUTRAD = 200NM SDEPTH = M
RD34NE = 0NM RD34SE = 0NM RD34SW = 0NM RD34NW = 0NM

[Ed Mahmoud]

To my uncalibrated eye, looks like a TD already.

[Chacor]

Code: Select all

                    *   EAST PACIFIC SHIPS INTENSITY FORECAST   *
                    *        GOES INPUT INCLUDED                *
                    *      INVEST  EP902008  05/28/08  12 UTC   *

TIME (HR)          0     6    12    18    24    36    48    60    72    84    96   108   120
V (KT) NO LAND    25    27    28    30    32    38    44    48    52    55    58    61    64
V (KT) LAND       25    27    28    30    32    38    44    48    52    46    49    52    55
V (KT) LGE mod    25    25    26    26    26    28    29    30    31    28    33    35    38

SHEAR (KTS)        9    10    11    15    14    18    18    19    14    17    16    21    15
SHEAR DIR        183   153   150   146   149   134   118    85    66    63    51    59    93
SST (C)         28.9  29.0  29.0  29.1  29.1  29.3  29.5  29.8  30.1  30.4  30.6  30.6  30.4
POT. INT. (KT)   151   151   151   152   153   155   157   161   164   167   169   169   167
200 MB T (C)   -54.1 -53.4 -53.1 -53.5 -53.7 -52.8 -53.8 -52.8 -53.6 -52.7 -53.5 -52.6 -53.4
TH_E DEV (C)       6     7     8     7     6     8     7     8     6     8     6    10     7
700-500 MB RH     79    78    80    82    81    82    82    82    81    81    79    79    78
GFS VTEX (KT)     14    12    11    10    10  LOST  LOST  LOST  LOST  LOST  LOST  LOST  LOST
850 MB ENV VOR   147   135   145   150   149   136   125   108    93   103   103   109    94
200 MB DIV        84    92   114   111   100   107   104    95    92    84    35    82    50
LAND (KM)        230   224   199   178   158   111    39    15    17     0    37   111   193
LAT (DEG N)     10.0  10.3  10.6  10.9  11.2  12.1  12.8  13.4  13.8  14.1  14.2  14.3  14.3
LONG(DEG W)     88.0  88.0  87.9  88.0  88.0  88.5  89.1  89.9  90.7  91.5  92.4  93.5  94.7
STM SPEED (KT)     4     3     3     3     4     5     5     5     4     4     5     5     6

  FORECAST TRACK FROM BAMM      INITIAL HEADING/SPEED (DEG/KT): 65/  4      CX,CY:   4/  2
  T-12 MAX WIND:  25            PRESSURE OF STEERING LEVEL (MB):  511  (MEAN=582)
  GOES IR BRIGHTNESS TEMP. STD DEV. 100-300 KM RAD:  27.5 (MEAN=18.0)
  % GOES IR PIXELS WITH T < -20 C    50-200 KM RAD:  65.0 (MEAN=65.7)

                        INDIVIDUAL CONTRIBUTIONS TO INTENSITY CHANGE
                         6   12   18   24   36   48   60   72   84   96  108  120
                        ----------------------------------------------------------
  SAMPLE MEAN CHANGE     0.   0.   0.   1.   1.   1.   0.   0.  -1.  -1.  -2.  -2.
  SST POTENTIAL          0.   1.   2.   4.  10.  16.  23.  29.  34.  37.  39.  41.
  VERTICAL SHEAR         1.   2.   3.   3.   4.   4.   3.   3.   2.   3.   2.   2.
  PERSISTENCE            0.   0.   0.  -1.  -1.  -1.  -1.  -1.  -1.  -1.  -1.  -1.
  200/250 MB TEMP.       0.   0.  -1.  -1.  -2.  -2.  -3.  -4.  -4.  -4.  -3.  -2.
  THETA_E EXCESS         0.   0.  -1.  -1.  -1.  -2.  -2.  -3.  -3.  -3.  -3.  -3.
  700-500 MB RH          0.   1.   2.   2.   4.   6.   7.   8.   8.   8.   8.   7.
  GFS VORTEX TENDENCY    0.  -1.  -3.  -4.  -5.  -5.  -5.  -5.  -5.  -5.  -5.  -4.
  850 MB ENV VORTICITY   0.   0.   1.   1.   2.   3.   5.   6.   8.   9.  11.  12.
  200 MB DIVERGENCE      1.   2.   3.   4.   6.   7.   6.   6.   4.   2.   1.   0.
  ZONAL STORM MOTION    -1.  -1.  -2.  -4.  -6.  -7.  -9.  -9.  -9.  -8.  -8.  -8.
  STEERING LEVEL PRES    0.   0.   0.   0.   0.   0.  -1.  -1.  -1.  -1.  -1.  -1.
  DAYS FROM CLIM. PEAK   0.   0.   0.   0.  -1.  -1.  -1.  -2.  -2.  -3.  -3.  -4.
                        ----------------------------------------------------------
  SUB-TOTAL CHANGE       1.   2.   4.   6.  12.  18.  23.  27.  30.  32.  35.  38.

  SATELLITE ADJUSTMENTS ----------------------------------------------------------
  MEAN ADJUSTMENT        0.   0.  -1.  -1.  -1.  -2.  -2.  -2.  -1.  -1.  -1.  -1.
  GOES IR STD DEV        1.   1.   2.   3.   3.   4.   3.   2.   2.   1.   2.   2.
  GOES IR PIXEL COUNT    0.   0.   0.   0.  -1.  -1.  -1.  -1.   0.   0.   0.   0.
                        ----------------------------------------------------------
  TOTAL ADJUSTMENT       0.   1.   1.   1.   1.   1.   0.   0.   0.   1.   1.   1.
                        ----------------------------------------------------------
  TOTAL CHANGE (KT)      2.   3.   5.   7.  13.  19.  23.  27.  30.  33.  36.  39.

** E. PACIFIC 2008 RI INDEX EP902008     INVEST 05/28/08  12 UTC **
           ( 25 KT OR MORE MAX WIND INCREASE IN NEXT 24 HR)
 
 12 HR PERSISTENCE (KT):   0.0 Range:-20.0 to  45.0 Scaled/Wgted Val:  0.3/  0.4
 850-200 MB SHEAR (KT) :  11.9 Range: 18.5 to   1.6 Scaled/Wgted Val:  0.4/  0.4
 D200 (10**7s-1)       : 100.2 Range:-11.0 to 127.0 Scaled/Wgted Val:  0.8/  0.4
 POT = MPI-VMAX (KT)   : 126.8 Range: 37.1 to 131.4 Scaled/Wgted Val:  1.0/  1.4
 850-700 MB REL HUM (%):  83.0 Range: 63.0 to  88.0 Scaled/Wgted Val:  0.8/  0.5
 % area w/pixels <-30 C:  61.0 Range: 26.0 to 100.0 Scaled/Wgted Val:  0.5/  0.2
 STD DEV OF IR BR TEMP :  22.1 Range: 35.4 to   2.7 Scaled/Wgted Val:  0.4/  0.6
 
 Prob of RI for 25 kt RI threshold=    34% is   2.7 times the sample mean(12.5%)
 Prob of RI for 30 kt RI threshold=    24% is   2.9 times the sample mean( 8.3%)
 Prob of RI for 35 kt RI threshold=    19% is   3.2 times the sample mean( 5.8%)

   ##         ANNULAR HURRICANE INDEX (AHI) EP902008     INVEST 05/28/08  12 UTC         ##
   ## STORM NOT ANNULAR, SCREENING STEP FAILED, NPASS=5 NFAIL=2                          ##
   ## AHI=  0   (AHI OF 100 IS BEST FIT TO ANN. STRUC., 1 IS MARGINAL, 0 IS NOT ANNULAR) ##
   ##     ANNULAR INDEX RAN NORMALLY             


That's the full 12Z SHIPS run. Look at the RI possibilities: 2.7 times over mean for 25 kts and 3.2 times for 35 kts.

[KWT]

Given the estimates are now at 1.5 if there is conclusive proof of a LLC we quite likely see an upgrade to TD status later today.

Looking better and better now as well...interesting to see they show the chance of some RI, its got a good enough structure to be have at least the chance of doing so with a pretty decent strength circulation from what I've seen. We will see, still think its going to have to stop drifting of the ENE though otherwise land interaction could start to a problem...or maybe a help if powerful convection blows up overland???

[Chacor]

Oh, TAFB (part of TPC)'s internal satfix is also T1.5 right now.

[Ed Mahmoud]

UK Met tries to get it into the Bay of Campeche, aiming it at Tehuanepec, but predicts it dies on the coast...

Landfall as 'strong' is an improvement over yesterday's landfall as 'intense'. I have no idea what those terms imply.

MET OFFICE TROPICAL CYCLONE GUIDANCE FOR NORTH-EAST PACIFIC



AND ATLANTIC



GLOBAL MODEL DATA TIME 00UTC 28.05.2008



NEW TROPICAL STORM FORECAST TO DEVELOP AFTER 12 HOURS

FORECAST POSITION AT T+ 12 : 8.3N 90.4W



VERIFYING TIME POSITION STRENGTH TENDENCY

-------------- -------- -------- --------

12UTC 28.05.2008 8.3N 90.4W WEAK

00UTC 29.05.2008 9.1N 89.2W MODERATE INTENSIFYING SLIGHTLY

12UTC 29.05.2008 10.0N 89.1W STRONG INTENSIFYING RAPIDLY

00UTC 30.05.2008 11.1N 89.7W STRONG INTENSIFYING SLIGHTLY

12UTC 30.05.2008 12.5N 89.9W STRONG LITTLE CHANGE

00UTC 31.05.2008 13.6N 90.3W MODERATE WEAKENING RAPIDLY

12UTC 31.05.2008 13.9N 92.6W WEAK WEAKENING RAPIDLY

00UTC 01.06.2008 BELOW TROPICAL STORM STRENGTH





THIS INFORMATION IS PROVIDED AS GUIDANCE FOR TROPICAL CYCLONE

RSMCS. IT REQUIRES INTERPRETATION BY TROPICAL CYCLONE SPECIALISTS

AND SHOULD NOT BE CONSIDERED AS A FINAL PRODUCT





MET OFFICE, EXETER, UK

[NDG]

By looking at early vis sat loop, I still have hard time finding any SE surface winds on the SE quadrant of the broad circulation. But looking better.

[CrazyC83]

QuikSCAT: no closed circulation at all, 30 kt winds



http://manati.orbit.nesdis.noaa.gov/sto ... 3_90ds.png

[Chacor]

That pass is from 2341 UTC yesterday, about 14 hours ago.

[cycloneye]

Crazy,you have to check the time of the pass at the bottom right side and see if is recent or not.

[KWT]

This system is looking good even if its not totally closed off, I do agree with NDG to a certain extent but the circulation it has got if its not closed is very close and also pretty strong and vigourous from the looks of things.

[RL3AO]

[Thunder44]

This is the QS pass from 12:24 UTC this morning. It missed most of the circulation but there are some northerly winds on the west side.

[KWT]

Yep that north wind on the western side is a good indication that we are close if not already got a closed circulation so thats interesting news just a shame it didn't get the whole thing though.

[Chacor]

First few visibles coming in now.

[KWT]

Northern side of the invest isn't that impressive but the southerm area of convection looks very good and its not hard to see the curveature of the low pressure circulation, wrapping up quite nicely, I think that probably is a tropical depression.