EPAC: IGNACIO - Post-Tropical

[Kingarabian]

I have to point that it still needs to be watched. If that ghostly shear continues to harass its development, it could go more south than thought. GFS and Euro are basically showing a very close call with the Big Island.

Also worth noting, for the 3rd advisory in a row its been heading south of the official track (unless I have the center wrong):

[Yellow Evan]

27/1730 UTC 12.7N 140.2W T4.5/4.5 IGNACIO -- Central Pacific

[Yellow Evan]

----- Current Analysis -----
Date : 27 AUG 2015 Time : 183000 UTC
Lat : 13:11:41 N Lon : 140:06:53 W


CI# /Pressure/ Vmax
4.6 / 979.7mb/ 79.6kt


Final T# Adj T# Raw T#
4.6 4.6 4.5

[Yellow Evan]

Code: Select all

                    * EAST PACIFIC SHIPS INTENSITY FORECAST          *
                    * IR SAT DATA AVAILABLE,       OHC AVAILABLE     *
                    *  IGNACIO     EP122015  08/27/15  18 UTC        *

TIME (HR)          0     6    12    18    24    36    48    60    72    84    96   108   120
V (KT) NO LAND    80    83    87    90    94    96    97   100    96    90    88    83    82
V (KT) LAND       80    83    87    90    94    96    97   100    96    90    88    83    82
V (KT) LGE mod    80    83    87    90    93    97   100   100    98    93    85    78    72
Storm Type      TROP  TROP  TROP  TROP  TROP  TROP  TROP  TROP  TROP  TROP  TROP  TROP  TROP

SHEAR (KT)        12    10    12    11    10    11     2     2     8    11    14    18    22
SHEAR ADJ (KT)     8     7     0    -1    -1    -2    -2    -4    -6     1     3     2    -1
SHEAR DIR         87    78    76    74    73   108    69   166   274   250   236   219   231
SST (C)         28.6  28.5  28.5  28.5  28.4  28.0  27.7  27.5  27.4  27.4  27.4  27.6  27.8
POT. INT. (KT)   151   150   150   150   148   143   140   138   137   137   137   139   141
200 MB T (C)   -52.1 -51.3 -51.6 -51.9 -51.7 -51.4 -51.3 -51.2 -51.1 -50.9 -51.7 -51.4 -51.6
TH_E DEV (C)       8     8     8     8     8     9    10    11    10    10     9     9     8
700-500 MB RH     64    67    67    67    65    63    59    55    56    58    62    60    61
MODEL VTX (KT)    22    22    23    23    25    26    25    28    29    27    29    28    30
850 MB ENV VOR    59    57    51    42    48    54    47    56    52    64    74    69    83
200 MB DIV        59    55    54    45    25     3    15    -4    -3    31    50    49    62
700-850 TADV      -5    -4    -3    -3    -2     0     0     0     0     4     9    13    10
LAND (KM)       1722  1603  1484  1365  1246  1071   912   744   562   405   280   137    66
LAT (DEG N)     12.7  13.2  13.6  14.1  14.5  15.3  16.0  16.7  17.5  18.2  18.9  19.7  20.5
LONG(DEG W)    140.3 141.3 142.3 143.3 144.3 145.7 147.0 148.4 149.9 151.2 152.2 153.5 154.9
STM SPEED (KT)    11    11    11    11     9     8     7     8     7     7     7     7     8
HEAT CONTENT      11    11    15    22    27    24    26    30    36    31    34    42    28

  FORECAST TRACK FROM OFCI      INITIAL HEADING/SPEED (DEG/KT):280/ 11      CX,CY: -10/  2
  T-12 MAX WIND:  75            PRESSURE OF STEERING LEVEL (MB):  511  (MEAN=581)
  GOES IR BRIGHTNESS TEMP. STD DEV.  50-200 KM RAD:   3.2 (MEAN=14.5)
  % GOES IR PIXELS WITH T < -20 C    50-200 KM RAD: 100.0 (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.   2.   1.  -2.  -5.  -8. -11. -13. -15. -16.
  VERTICAL SHEAR MAG    -1.  -1.  -2.  -2.  -2.   1.   4.   5.   6.   6.   4.   2.
  VERTICAL SHEAR ADJ     0.  -1.  -1.  -1.   0.   0.   0.   1.   1.   0.   0.   0.
  VERTICAL SHEAR DIR     1.   2.   3.   4.   6.   8.   8.   7.   5.   4.   3.   2.
  PERSISTENCE            1.   2.   2.   2.   1.   1.   0.   0.   0.   0.   0.   0.
  200/250 MB TEMP.       0.  -1.  -2.  -3.  -5.  -7.  -9. -10. -11. -11. -11. -10.
  THETA_E EXCESS         0.   0.   0.   0.   0.   0.   1.   1.   1.   2.   2.   2.
  700-500 MB RH          0.   0.   0.   1.   1.   1.   1.   1.   1.   2.   2.   2.
  MODEL VTX TENDENCY     0.   1.   1.   4.   5.   6.   9.  10.   9.  12.  10.  12.
  850 MB ENV VORTICITY   0.   0.   0.   0.   1.   1.   1.   2.   2.   3.   4.   5.
  200 MB DIVERGENCE      0.   0.   1.   1.   1.   0.   0.   0.   0.   0.   0.  -1.
  850-700 T ADVEC        0.   0.   0.   0.   0.   0.   0.   0.   0.   0.   0.   1.
  ZONAL STORM MOTION     0.   0.   1.   1.   1.   2.   2.   2.   2.   2.   2.   2.
  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.   2.   2.   2.   2.
  GOES PREDICTORS        2.   4.   5.   6.   6.   6.   5.   4.   3.   2.   2.   2.
  OCEAN HEAT CONTENT     0.   0.   0.   0.   0.   0.   1.   1.   1.   1.   1.   1.
                        ----------------------------------------------------------
  TOTAL CHANGE           3.   7.  10.  14.  16.  17.  20.  16.  10.   8.   3.   2.

   ** 2013 E. Pacific RI INDEX EP122015 IGNACIO    08/27/15  18 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) :  11.1 Range: 18.7 to   1.4 Scaled/Wgted Val:  0.4/  0.6
 POT = MPI-VMAX (KT)   :  69.7 Range: 40.3 to 141.7 Scaled/Wgted Val:  0.3/  0.3
 STD DEV OF IR BR TEMP :   3.2 Range: 38.9 to   2.4 Scaled/Wgted Val:  1.0/  1.0
 Heat content (KJ/cm2) :  17.2 Range:  3.6 to  75.9 Scaled/Wgted Val:  0.2/  0.2
 D200 (10**7s-1)       :  47.6 Range:-11.0 to 135.3 Scaled/Wgted Val:  0.4/  0.3
 % area w/pixels <-30 C: 100.0 Range: 41.4 to 100.0 Scaled/Wgted Val:  1.0/  0.5
 850-700 MB REL HUM (%):  68.8 Range: 57.6 to  96.8 Scaled/Wgted Val:  0.3/  0.0
 
 Prob of RI for 25 kt RI threshold=    29% is   2.2 times the sample mean(13.1%)
 Prob of RI for 30 kt RI threshold=    24% is   2.8 times the sample mean( 8.7%)
 Prob of RI for 35 kt RI threshold=    17% is   2.8 times the sample mean( 6.0%)
 Prob of RI for 40 kt RI threshold=    14% is   3.1 times the sample mean( 4.3%)

[Kingarabian]

What's with these EPAC storms this year and them not being able to develop eye's. It's like a Guillermo part deux.

[Yellow Evan]

Also dry air to the west that it needs to mix out. Since then, the storm presentation; however, seems to have improved slightly and banding features may be increasing.

[Kingarabian]

Eye may try to clear out soon:

[Yellow Evan]

See no real indications of it clearing out on VIS, but I think it'll start clearing tonight.

[Kingarabian]

See no real indications of it clearing out on VIS, but I think it'll start clearing tonight.

Probably because the eyewall is weak everywhere except to the south. I'm thinking this is weaker than 80kts. I personally thought it was 80kts yesterday while banding was plenty.

[Kingarabian]

WTPA43 PHFO 272039
TCDCP3

HURRICANE IGNACIO DISCUSSION NUMBER 12
NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI EP122015
1100 AM HST THU AUG 27 2015

HURRICANE IGNACIO PASSED WEST OF 140W LONGITUDE SHORTLY AFTER 1500
UTC...MAKING IT THE EIGHTH TROPICAL CYCLONE IN THE CENTRAL NORTH
PACIFIC BASIN FOR THE 2015 HURRICANE SEASON. IGNACIO CONTINUES TO
HAVE A CLOUD-FILLED EYE WITH PERSISTENT CLOUD TOPS COLDER THAN -80C
AND AN OVERALL SYMMETRIC OUTFLOW. A 1642 UTC SSMI/S PASS AND
LIGHTNING DATA SHOWED THAT THE MOST ACTIVE DEEP CONVECTION HAS BEEN
OCCURRING SOUTH AND SOUTHWEST OF THE CENTER. DVORAK INTENSITY
ESTIMATES CAME IN AT 77 KT FROM SAB AND JTWC...AND 90 KT FROM PHFO.
A 1730 UTC CIMSS ADT ESTIMATE WAS CLOSE TO 80 KT. BASED ON A BLEND
OF THESE DATA...THE INITIAL INTENSITY FOR THIS ADVISORY WILL BE HELD
AT 80 KT.

IGNACIO IS MOVING AT 280/11 KT AND APPEARS TO HAVE MOVED A BIT LEFT
OF THE PREVIOUS FORECAST TRACK. DESPITE THIS SLIGHT WOBBLE...THE
GENERAL TRACK FORECAST REMAINS UNCHANGED WITH A SUBTROPICAL RIDGE TO
THE NORTH OF THE CYCLONE CONTINUING TO STEER IT TOWARD THE
WEST-NORTHWEST...THOUGH WITH A SLOWER FORWARD MOTION STARTING LATER
TODAY OR TONIGHT. FOR THIS FORECAST PACKAGE...THE DYNAMICAL
GUIDANCE SPREAD HAS BECOME TIGHTER...WITH THE ECMWF HAVING SHIFTED
NORTH TO LINE UP CLOSER WITH THE GFS. THE SHIFT APPEARS TO BE DUE TO
THE ECMWF SHOWING A STRONGER CYCLONE WITH LESS WEAKENING DUE TO
VERTICAL WIND SHEAR. THE CURRENT FORECAST IS CLOSE TO THE PREVIOUS
FORECAST AND MODEL CONSENSUS THROUGH 72 HOURS...THEN NUDGED
NORTHWARD CLOSER TO THE GFS AND ECMWF FOR 96 AND 120 HOURS.

THE HURRICANE SHOULD REMAIN OVER WARM SEA SURFACE TEMPERATURES AND
LIGHT TO MODERATE VERTICAL WIND SHEAR DURING THE NEXT COUPLE OF
DAYS. VERTICAL WIND SHEAR IS EXPECTED TO INCREASE AFTER 72
HOURS...WHICH SHOULD BEGIN A GRADUAL WEAKENING. THE INTENSITY
FORECAST FOR THIS PACKAGE IS CLOSE TO THE PREVIOUS FORECAST AND
GRADUALLY STRENGTHENS IGNACIO TO A MAJOR HURRICANE OVER THE NEXT 24
TO 48 HOURS...FOLLOWED BY GRADUAL WEAKENING AFTERWARD. THIS IS CLOSE
TO THE IVCN CONSENSUS THROUGH 48 HOURS...THEN SLIGHTLY BELOW IT FROM
72 HOURS THROUGH THE END OF THE FORECAST PERIOD.


FORECAST POSITIONS AND MAX WINDS

INIT 27/2100Z 12.9N 140.8W 80 KT 90 MPH
12H 28/0600Z 13.6N 142.3W 85 KT 100 MPH
24H 28/1800Z 14.5N 144.2W 95 KT 110 MPH
36H 29/0600Z 15.3N 145.7W 100 KT 115 MPH
48H 29/1800Z 16.1N 147.1W 100 KT 115 MPH
72H 30/1800Z 17.5N 149.9W 90 KT 105 MPH
96H 31/1800Z 19.5N 152.5W 80 KT 90 MPH
120H 01/1800Z 21.0N 154.5W 70 KT 80 MPH

$$
FORECASTER KODAMA

[Yellow Evan]

Eye clearing out on VIS slightly.

[Kingarabian]

Looks like shear is increasing from the south.

[Yellow Evan]

:uarrow:

http://i.imgur.com/9KuramA.gif

Looks like shear is increasing from the south.

Maybe, but dry air also may be getting in on the NNW, which in EPAC hurricanes, often causes the CDO to shrink. Eye at least may be trying to clear.

[Kingarabian]

The reason I say shear is because of that sharp edge cut off (flat convection) to the south.

[Yellow Evan]

----- Current Analysis -----
Date : 27 AUG 2015 Time : 210000 UTC
Lat : 12:45:00 N Lon : 140:38:46 W


CI# /Pressure/ Vmax
4.6 / 979.9mb/ 79.6kt


Final T# Adj T# Raw T#
4.6 4.6 4.7

Center Temp : -74.6C Cloud Region Temp : -76.8C

[Kingarabian]

18z GFS shifts more SW closer to the big Island. Reason so is because it has it around 10mb weaker.

[Yellow Evan]

Also has a stronger ridge.

[Kingarabian]

Looks like it wants to try the big eye thing again

[Yellow Evan]

27/2330 UTC 13.0N 141.4W T4.5/4.5 IGNACIO -- Central Pacific

[Kingarabian]

18z HWRF has a Maui landfall.