EPAC: IGNACIO - Post-Tropical

[cycloneye]

EP, 95, 2015082112, , BEST, 0, 125N, 1237W, 20, 1009, DB

[Yellow Evan]

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                    * EAST PACIFIC SHIPS INTENSITY FORECAST          *
                    * IR SAT DATA AVAILABLE,       OHC AVAILABLE     *
                    *  INVEST      EP952015  08/21/15  12 UTC        *

TIME (HR)          0     6    12    18    24    36    48    60    72    84    96   108   120
V (KT) NO LAND    20    22    25    28    32    41    49    56    58    61    61    61    60
V (KT) LAND       20    22    25    28    32    41    49    56    58    61    61    61    60
V (KT) LGE mod    20    21    22    24    25    29    34    39    44    49    53    56    57
Storm Type      TROP  TROP  TROP  TROP  TROP  TROP  TROP  TROP  TROP  TROP  TROP  TROP  TROP

SHEAR (KT)         4     6     6     6     7     8    11    10    11     5    10    13    16
SHEAR ADJ (KT)    -5    -3    -3    -2    -1     0    -1    -6    -3    -5    -5    -1     0
SHEAR DIR        360   353     3     7   356     1    14    12   349   321   262   267   274
SST (C)         29.4  29.3  29.3  29.3  29.2  29.0  28.9  28.8  28.8  28.7  28.4  27.8  27.4
POT. INT. (KT)   159   157   157   157   156   154   153   152   152   151   148   142   138
200 MB T (C)   -52.2 -52.2 -52.1 -52.2 -52.3 -52.2 -52.5 -52.5 -52.8 -52.7 -53.1 -52.8 -53.0
TH_E DEV (C)       9     9     9     9     8     8     8     8     8     9     8     9     9
700-500 MB RH     52    51    53    57    59    60    62    58    55    55    52    50    46
MODEL VTX (KT)     3     4     5     4     4     5     6     6     5     6     6  LOST  LOST
850 MB ENV VOR     7     4     7    12     9    21    37    25    27    25    28    20     6
200 MB DIV         5    16    32    42    42    40    32    17    -7    -4    13    12    -2
700-850 TADV       0     0     0     0     1     1     0     0     0     1     1     4     8
LAND (KM)       1818  1870  1925  1978  2034  2127  2234  2322  2395  2213  2032  1839  1625
LAT (DEG N)     12.5  12.7  12.8  12.9  13.0  13.3  13.4  13.7  14.1  14.6  15.1  15.7  16.3
LONG(DEG W)    123.7 124.6 125.5 126.3 127.1 128.5 130.0 131.5 133.0 134.6 136.2 137.9 139.8
STM SPEED (KT)     9     9     8     8     7     7     7     7     8     8     8    10     9
HEAT CONTENT      34    40    44    48    51    51    31    21    21    21    31    31     9

  FORECAST TRACK FROM BAMM      INITIAL HEADING/SPEED (DEG/KT):275/ 10      CX,CY:  -9/  1
  T-12 MAX WIND:  20            PRESSURE OF STEERING LEVEL (MB):  516  (MEAN=581)
  GOES IR BRIGHTNESS TEMP. STD DEV.  50-200 KM RAD:  16.2 (MEAN=14.5)
  % GOES IR PIXELS WITH T < -20 C    50-200 KM RAD:  70.0 (MEAN=65.0)

                        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.   0.   1.   7.  15.  23.  30.  34.  37.  39.  40.
  VERTICAL SHEAR MAG     1.   2.   3.   4.   6.   7.   7.   7.   7.   7.   7.   6.
  VERTICAL SHEAR ADJ     0.   1.   1.   1.   1.   1.   2.   2.   2.   2.   3.   3.
  VERTICAL SHEAR DIR     0.   0.   0.   1.   1.   2.   2.   2.   1.  -1.  -3.  -4.
  PERSISTENCE            0.   0.   0.  -1.  -1.  -1.  -1.  -1.  -1.  -1.   0.   0.
  200/250 MB TEMP.       0.   0.  -1.  -2.  -3.  -4.  -5.  -7.  -7.  -7.  -7.  -7.
  THETA_E EXCESS         0.   0.   0.   0.   0.   0.   0.   0.   0.   0.   0.   0.
  700-500 MB RH          0.   0.   0.   0.   0.   0.   0.   0.   1.   0.   0.   0.
  MODEL VTX TENDENCY     0.   1.   1.   1.   3.   3.   4.   3.   4.   4.   4.   4.
  850 MB ENV VORTICITY   0.   0.   0.   0.   0.   0.   0.   0.   0.   0.   0.   0.
  200 MB DIVERGENCE      0.   0.   0.   0.   0.   0.   0.   0.   0.   0.   0.   0.
  850-700 T ADVEC        0.   0.   0.   0.   0.   0.   0.   0.   0.   0.   0.   1.
  ZONAL STORM MOTION     0.   0.   1.   1.   1.   1.   1.   1.   1.   1.   1.   1.
  STEERING LEVEL PRES    0.   0.   0.   0.   0.  -1.  -1.  -1.  -1.  -1.  -1.  -1.
  DAYS FROM CLIM. PEAK   0.   0.   0.   0.   0.   0.   0.   1.   1.   2.   2.   2.
  GOES PREDICTORS        1.   2.   2.   2.   2.   0.  -1.  -2.  -3.  -4.  -4.  -4.
  OCEAN HEAT CONTENT     0.   1.   1.   2.   3.   4.   3.   2.   2.   2.   2.   1.
                        ----------------------------------------------------------
  TOTAL CHANGE           2.   5.   8.  12.  21.  29.  36.  38.  41.  41.  41.  40.

   ** 2013 E. Pacific RI INDEX EP952015 INVEST     08/21/15  12 UTC **
           ( 30 KT OR MORE MAX WIND INCREASE IN NEXT 24 HR)
 
 12 HR PERSISTENCE (KT):   0.0 Range:-22.0 to  38.5 Scaled/Wgted Val:  0.4/  0.8
 850-200 MB SHEAR (KT) :   5.8 Range: 18.7 to   1.4 Scaled/Wgted Val:  0.7/  1.1
 POT = MPI-VMAX (KT)   : 137.2 Range: 40.3 to 141.7 Scaled/Wgted Val:  1.0/  1.0
 STD DEV OF IR BR TEMP :  16.2 Range: 38.9 to   2.4 Scaled/Wgted Val:  0.6/  0.6
 Heat content (KJ/cm2) :  43.4 Range:  3.6 to  75.9 Scaled/Wgted Val:  0.6/  0.5
 D200 (10**7s-1)       :  27.4 Range:-11.0 to 135.3 Scaled/Wgted Val:  0.3/  0.2
 % area w/pixels <-30 C:  64.0 Range: 41.4 to 100.0 Scaled/Wgted Val:  0.4/  0.2
 850-700 MB REL HUM (%):  69.4 Range: 57.6 to  96.8 Scaled/Wgted Val:  0.3/  0.0
 
 Prob of RI for 25 kt RI threshold=    42% is   3.2 times the sample mean(13.1%)
 Prob of RI for 30 kt RI threshold=    29% is   3.3 times the sample mean( 8.7%)
 Prob of RI for 35 kt RI threshold=    20% is   3.4 times the sample mean( 6.0%)
 Prob of RI for 40 kt RI threshold=    16% is   3.7 times the sample mean( 4.3%)

[Yellow Evan]

A small area of disorganized showers and thunderstorms, about 1200
miles southwest of the Baja California peninsula, is associated with
a tropical wave. Some gradual development of this system is
possible over the weekend while the disturbance moves westward at
about 10 mph.
* Formation chance through 48 hours...low...20 percent
* Formation chance through 5 days...medium...60 percent

[Yellow Evan]

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                    * EAST PACIFIC SHIPS INTENSITY FORECAST          *
                    * IR SAT DATA AVAILABLE,       OHC AVAILABLE     *
                    *  INVEST      EP952015  08/21/15  18 UTC        *

TIME (HR)          0     6    12    18    24    36    48    60    72    84    96   108   120
V (KT) NO LAND    20    22    24    27    30    37    45    51    54    55    55    54    53
V (KT) LAND       20    22    24    27    30    37    45    51    54    55    55    54    53
V (KT) LGE mod    20    21    21    23    24    27    32    36    41    46    49    51    51
Storm Type      TROP  TROP  TROP  TROP  TROP  TROP  TROP  TROP  TROP  TROP  TROP  TROP  TROP

SHEAR (KT)         5     8     8     7    10     8     8     6    11     7     8    15    19
SHEAR ADJ (KT)    -6    -5    -3    -3    -2     1    -5    -5    -2    -2     0     0    -1
SHEAR DIR        335   348     2   354   353    14   359   345   348   292   267   263   287
SST (C)         29.3  29.3  29.3  29.2  29.2  29.0  28.9  28.8  28.8  28.6  28.2  27.7  27.4
POT. INT. (KT)   158   157   157   156   156   154   153   152   152   150   146   142   139
200 MB T (C)   -52.2 -52.0 -52.1 -52.2 -52.2 -52.3 -52.6 -52.6 -52.7 -52.9 -53.1 -52.8 -52.8
TH_E DEV (C)      10    10     9     8     8     8     8     8     8     8     8     8     8
700-500 MB RH     50    52    56    59    60    63    62    60    59    58    56    53    52
MODEL VTX (KT)     0  LOST  LOST  LOST  LOST  LOST  LOST  LOST  LOST  LOST  LOST  LOST  LOST
850 MB ENV VOR    13    19    28    23    25    42    47    45    35    37    35    27    17
200 MB DIV        10    26    39    39    33    40    55    29    15    22    10     9     0
700-850 TADV      -2    -2    -2     0     0     0     0    -1     3     1     2     4     9
LAND (KM)       1763  1819  1878  1939  2003  2126  2234  2322  2368  2183  1978  1739  1484
LAT (DEG N)     12.9  13.0  13.1  13.1  13.1  13.2  13.4  13.7  14.3  14.9  15.2  15.6  16.2
LONG(DEG W)    123.4 124.3 125.2 126.0 126.8 128.4 130.0 131.5 133.2 134.8 136.7 138.9 141.2
STM SPEED (KT)    10     9     8     8     8     8     8     8     8     9    10    11    12
HEAT CONTENT      29    34    38    43    49    52    31    21    21    21    40    16     8

[Yellow Evan]

Shower and thunderstorm activity associated with a tropical wave
located about 1200 miles southwest of the southern tip of the Baja
California peninsula remains limited. Some gradual development of
this system is possible during the next several days while it moves
westward at about 10 mph.
* Formation chance through 48 hours...low...20 percent
* Formation chance through 5 days...medium...40 percent

[cycloneye]

Shower and thunderstorm activity associated with a broad area of
low pressure located about 1300 miles southwest of the southern tip
of the Baja California peninsula remains limited. Some gradual
development of this system is possible during the next several days
while it moves westward at 5 to 10 mph.
* Formation chance through 48 hours...low...20 percent
* Formation chance through 5 days...medium...40 percent

[Yellow Evan]

ECMWF merges this with a system to its right. May briefly become a TD or weak TS at best.

[Yellow Evan]

Very complex setup here but both GFS/ECMWF eventually merge this with the 0/20.

Shower and thunderstorm activity associated with a broad area of low
pressure located about 1450 miles west-southwest of the southern
tip of the Baja California peninsula remains limited. Some gradual
development of this system is possible through early next week while
it moves westward at 5 to 10 mph.
* Formation chance through 48 hours...low...20 percent
* Formation chance through 5 days...medium...40 percent

[Yellow Evan]

0z CMC brings 95E into San Fransico:



Sometimes idk what life would be like without the CMC.

[Extratropical94]

1. Shower activity associated with a broad, slow-moving area of low
pressure located about 1400 miles west-southwest of the southern tip
of the Baja California peninsula remains limited and disorganized.
Environmental conditions are conducive for slow development as it
merges with a disturbance approaching it from the east, and a
tropical depression is likely to form later this week while the
system begins to moves westward to west-northwestward at 10 mph.
* Formation chance through 48 hours...low...20 percent
* Formation chance through 5 days...medium...60 percent

[Extratropical94]

1. The circulation associated with a slow-moving low pressure area
located about 1400 miles southwest of the southern tip of the Baja
California peninsula has changed little in organization since
yesterday. Cloudiness and shower activity also remains
disorganized. However, environmental conditions are expected to be
conducive for gradual development, and a tropical depression is
likely to form later this week while the low begins to moves west-
northwestward and then northwestward at 10 mph.
* Formation chance through 48 hours...low...20 percent
* Formation chance through 5 days...high...70 percent

[Yellow Evan]

1. Showers and thunderstorms are showing signs of organization in
association with a slow-moving low pressure area located about 1450
miles southwest of the southern tip of the Baja California
peninsula. Environmental conditions are expected to be conducive
for gradual development, and a tropical depression is likely to form
in a few days while the low moves west-northwestward at 10 mph.
* Formation chance through 48 hours...medium...50 percent
* Formation chance through 5 days...high...70 percent

[Extratropical94]

Satellite data overnight that the circulation of the slow-moving low
pressure area located about 1500 miles west-southwest of the
southern tip of the Baja California peninsula is gradually becoming
better defined. Shower and thunderstorm activity associated with
this system has also become better organized since yesterday.
Environmental conditions are expected to be conducive for continued
gradual development, and a tropical depression is likely to form
during the next day or two while the low begins to move slowly
northwestward.
* Formation chance through 48 hours...medium...70 percent
* Formation chance through 5 days...high...80 percent

[Yellow Evan]

TROPICAL WEATHER OUTLOOK
NWS NATIONAL HURRICANE CENTER MIAMI FL
1100 AM PDT MON AUG 24 2015

For the eastern North Pacific...east of 140 degrees west longitude:

Satellite imagery indicates that the low pressure system located
about 1500 miles west-southwest of the southern tip of the Baja
California peninsula is slightly better defined than at this time
yesterday. Environmental conditions are expected to remain
conducive for continued gradual development, and any further
increase in organization of this disturbance could result in the
formation of a tropical cyclone. The low is expected to begin
moving slowly westward and then west-northwestward during the next
few days.
* Formation chance through 48 hours...high...70 percent
* Formation chance through 5 days...high...80 percent

[Yellow Evan]

12z ECMWF did bring this just north of Hawaii as a TC. I doubt it though.

[cycloneye]

Satellite imagery and satellite-derived surface winds indicate that
the low pressure system located about 1500 miles west-southwest of
the southern tip of the Baja California peninsula has continued to
become better organized. Environmental conditions are conducive
for additional development and only a slight increase in
organization would result in the formation of a tropical depression
tonight or Tuesday. The low is expected to move slowly
westward and then west-northwestward during the next few days.
* Formation chance through 48 hours...high...90 percent
* Formation chance through 5 days...high...90 percent

[Yellow Evan]

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                    * EAST PACIFIC SHIPS INTENSITY FORECAST          *
                    * IR SAT DATA AVAILABLE,       OHC AVAILABLE     *
                    *  INVEST      EP952015  08/25/15  00 UTC        *

TIME (HR)          0     6    12    18    24    36    48    60    72    84    96   108   120
V (KT) NO LAND    30    32    34    36    39    44    51    55    55    54    53    51    49
V (KT) LAND       30    32    34    36    39    44    51    55    55    54    53    51    49
V (KT) LGE mod    30    32    34    36    38    41    44    48    50    51    49    47    43
Storm Type      TROP  TROP  TROP  TROP  TROP  TROP  TROP  TROP  TROP  TROP  TROP  TROP  TROP

SHEAR (KT)        13    12    10     9     7     1     5     2     3     7    11    17    16
SHEAR ADJ (KT)    -7    -7    -7    -5    -1    -3    -5    -4    -3    -3    -4    -2     0
SHEAR DIR        118   136   141   139   139   111    93   149   224   250   252   263   280
SST (C)         29.1  29.0  29.0  28.9  28.8  28.7  28.5  28.4  28.1  27.8  27.7  27.5  27.3
POT. INT. (KT)   153   153   152   151   150   150   149   149   145   142   141   138   136
200 MB T (C)   -52.5 -52.6 -52.8 -52.8 -52.4 -52.7 -52.3 -52.6 -52.3 -52.5 -52.3 -52.6 -52.9
TH_E DEV (C)       8     8     8     8     8     8     9     8     9     9     9     9     9
700-500 MB RH     59    60    61    62    63    62    64    65    65    67    68    68    65
MODEL VTX (KT)     8     8     8     9     9     9     9     8     7     6     7     6     6
850 MB ENV VOR    38    41    38    45    47    41    35    29    13     5     4     2     0
200 MB DIV        46    46    44    41    56    26    35    28    33    23    32    23    42
700-850 TADV       0     0     0     0     0     0     0     0     0     2     3     5     6
LAND (KM)       2302  2351  2401  2443  2473  2355  2166  1951  1716  1514  1318  1141   974
LAT (DEG N)     13.2 xx.x  xx.x  xx.x  xx.x  xx.x  xx.x  xx.x  xx.x  xx.x  xx.x  xx.x  xx.x
LONG(DEG W)    130.7 xxx.x xxx.x xxx.x xxx.x xxx.x xxx.x xxx.x xxx.x xxx.x xxx.x xxx.x xxx.x
STM SPEED (KT)     4     5     5     4     5     7     9    10    10     9     9     8     8
HEAT CONTENT      18    18    19    20    21    17    18    21    18    14    12    17    19

  FORECAST TRACK FROM OFPI      INITIAL HEADING/SPEED (DEG/KT):280/  2      CX,CY:  -1/  0
  T-12 MAX WIND:  25            PRESSURE OF STEERING LEVEL (MB):  559  (MEAN=581)
  GOES IR BRIGHTNESS TEMP. STD DEV.  50-200 KM RAD:  21.8 (MEAN=14.5)
  % GOES IR PIXELS WITH T < -20 C    50-200 KM RAD:  58.0 (MEAN=65.0)

                        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.   3.   8.  14.  20.  24.  27.  28.  29.  30.
  VERTICAL SHEAR MAG     1.   1.   2.   3.   5.   6.   8.   9.  10.  10.   9.   8.
  VERTICAL SHEAR ADJ     0.   1.   2.   2.   2.   3.   3.   2.   2.   3.   4.   4.
  VERTICAL SHEAR DIR     0.   0.   1.   1.   2.   4.   5.   2.   0.  -3.  -4.  -5.
  PERSISTENCE            1.   1.   2.   2.   2.   2.   2.   1.   1.   1.   1.   0.
  200/250 MB TEMP.       0.   0.  -1.  -2.  -3.  -5.  -6.  -8.  -8.  -9.  -9.  -8.
  THETA_E EXCESS         0.   0.   0.   0.   0.   0.   0.   0.   0.   0.   0.   0.
  700-500 MB RH          0.   0.   0.   0.   1.   1.   1.   2.   2.   2.   3.   3.
  MODEL VTX TENDENCY     0.   0.   0.   1.   1.   1.  -1.  -2.  -3.  -2.  -2.  -3.
  850 MB ENV VORTICITY   0.   0.   0.   0.   0.   1.   1.   1.   1.   1.   0.   0.
  200 MB DIVERGENCE      0.   0.   1.   1.   1.   1.   1.   1.   0.   0.   0.  -1.
  850-700 T ADVEC        0.   0.   0.   0.   0.   0.   0.   0.   0.   0.   0.   1.
  ZONAL STORM MOTION     0.  -1.  -1.  -2.  -2.  -3.  -4.  -4.  -4.  -4.  -4.  -3.
  STEERING LEVEL PRES    0.   0.   0.   0.   0.   0.   0.   0.   0.   0.   0.   0.
  DAYS FROM CLIM. PEAK   0.   0.   0.   0.   0.   0.   0.   1.   2.   2.   2.   2.
  GOES PREDICTORS        0.   0.  -1.  -1.  -2.  -3.  -4.  -4.  -4.  -4.  -4.  -4.
  OCEAN HEAT CONTENT     0.   0.   0.   0.   0.   0.   0.   0.   0.   0.   0.   0.
                        ----------------------------------------------------------
  TOTAL CHANGE           2.   4.   6.   9.  14.  21.  25.  25.  24.  23.  21.  19.

   ** 2013 E. Pacific RI INDEX EP952015 INVEST     08/25/15  00 UTC **
           ( 30 KT OR MORE MAX WIND INCREASE IN NEXT 24 HR)
 
 12 HR PERSISTENCE (KT):   5.0 Range:-22.0 to  38.5 Scaled/Wgted Val:  0.4/  1.0
 850-200 MB SHEAR (KT) :  10.2 Range: 18.7 to   1.4 Scaled/Wgted Val:  0.5/  0.7
 POT = MPI-VMAX (KT)   : 121.9 Range: 40.3 to 141.7 Scaled/Wgted Val:  0.8/  0.9
 STD DEV OF IR BR TEMP :  21.8 Range: 38.9 to   2.4 Scaled/Wgted Val:  0.5/  0.5
 Heat content (KJ/cm2) :  19.2 Range:  3.6 to  75.9 Scaled/Wgted Val:  0.2/  0.2
 D200 (10**7s-1)       :  46.6 Range:-11.0 to 135.3 Scaled/Wgted Val:  0.4/  0.3
 % area w/pixels <-30 C:  50.0 Range: 41.4 to 100.0 Scaled/Wgted Val:  0.1/  0.1
 850-700 MB REL HUM (%):  73.0 Range: 57.6 to  96.8 Scaled/Wgted Val:  0.4/ -0.1
 
 Prob of RI for 25 kt RI threshold=    27% is   2.1 times the sample mean(13.1%)
 Prob of RI for 30 kt RI threshold=    21% is   2.4 times the sample mean( 8.7%)
 Prob of RI for 35 kt RI threshold=    15% is   2.5 times the sample mean( 6.0%)
 Prob of RI for 40 kt RI threshold=    10% is   2.3 times the sample mean( 4.3%)

[Yellow Evan]

000
WTPZ32 KNHC 250240
TCPEP2

BULLETIN
TROPICAL DEPRESSION TWELVE-E ADVISORY NUMBER 1
NWS NATIONAL HURRICANE CENTER MIAMI FL EP122015
800 PM PDT MON AUG 24 2015

...TWELFTH TROPICAL DEPRESSION OF THE SEASON FORMS OVER THE OPEN
WATERS OF THE TROPICAL PACIFIC...


SUMMARY OF 800 PM PDT...0300 UTC...INFORMATION
----------------------------------------------
LOCATION...13.1N 130.9W
ABOUT 1535 MI...2470 KM WSW OF THE SOUTHERN TIP OF BAJA CALIFORNIA
MAXIMUM SUSTAINED WINDS...35 MPH...55 KM/H
PRESENT MOVEMENT...W OR 270 DEGREES AT 3 MPH...6 KM/H
MINIMUM CENTRAL PRESSURE...1007 MB...29.74 INCHES


WATCHES AND WARNINGS
--------------------
There are no coastal watches or warnings in effect.


DISCUSSION AND 48-HOUR OUTLOOK
------------------------------
At 800 PM PDT (0300 UTC), the center of Tropical Depression Twelve-E
was located near latitude 13.1 North, longitude 130.9 West. The
depression is moving slowly toward the west near 3 mph (6 km/h) and
this general motion is expected to continue during the next
couple of days.

Maximum sustained winds are near 35 mph (55 km/h) with higher gusts.
Gradual strengthening is forecast during the next 48 hours and the
depression is forecast to become a tropical storm on Tuesday.

The estimated minimum central pressure is 1007 mb (29.74 inches).


HAZARDS AFFECTING LAND
----------------------
None


NEXT ADVISORY
-------------
Next complete advisory at 200 AM PDT.

$$
Forecaster Roberts

[Yellow Evan]

000
WTPZ42 KNHC 250243
TCDEP2

TROPICAL DEPRESSION TWELVE-E DISCUSSION NUMBER 1
NWS NATIONAL HURRICANE CENTER MIAMI FL EP122015
800 PM PDT MON AUG 24 2015

Conventional satellite imagery shows deep convection associated with
the area of low pressure located well southwest of the southern tip
of Baja California has become better organized and increased in
coverage since yesterday. Additionally, an 1852 UTC ASCAT-B
scatterometer overpass indicated that the surface circulation has
become sufficiently well defined. Accordingly, advisories are being
initiated on the twelfth tropical depression of the 2015 eastern
Pacific hurricane season. Dvorak intensity estimates support an
initial intensity of 30 kt. The cyclone is expected to traverse
warm sea surface temperatures and move within a marginally conducive
thermodynamic environment during the entire forecast period,
resulting in only gradual intensification. Around day 4, the
large-scale guidance and the SHIPS model show increasing
southwesterly shear which should induce a weakening trend and this
is also reflected in the official forecast.

The initial motion is estimated to be at 270/3 kt. A low- to
mid-level ridge extending westward to the north of the cyclone
from northern Mexico should influence a generally westward motion
during the next couple of days. Beyond the 48 hour period, global
and hurricane models indicate a deep-layer trough weakening the
ridge to the northeast of the Hawaiian Islands causing the
depression to turn toward the west-northwest and continuing in this
direction through day 5. The NHC forecast is based on a blend of
the GFEX (GFS/ECMWF) and the TVCX multi-model consensus.

FORECAST POSITIONS AND MAX WINDS

INIT 25/0300Z 13.1N 130.9W 30 KT 35 MPH
12H 25/1200Z 13.0N 131.4W 35 KT 40 MPH
24H 26/0000Z 12.8N 132.4W 40 KT 45 MPH
36H 26/1200Z 12.8N 133.7W 45 KT 50 MPH
48H 27/0000Z 13.2N 135.4W 50 KT 60 MPH
72H 28/0000Z 15.0N 139.4W 60 KT 70 MPH
96H 29/0000Z 16.6N 143.3W 60 KT 70 MPH
120H 30/0000Z 17.8N 146.5W 55 KT 65 MPH

$$
Forecaster Roberts

[Kingarabian]

06z continues to keep it weak but brings whatever is left of it into the big island. GFS and Euro are generally in agreement with the steering situation. The Ridge should weaken for this to eventually go NE.