EPAC: IGNACIO - Post-Tropical

[Yellow Evan]

Code: Select all

                    * EAST PACIFIC SHIPS INTENSITY FORECAST          *
                    * IR SAT DATA AVAILABLE,       OHC AVAILABLE     *
                    *  IGNACIO     EP122015  08/28/15  00 UTC        *

TIME (HR)          0     6    12    18    24    36    48    60    72    84    96   108   120
V (KT) NO LAND    80    81    83    86    88    90    90    87    83    80    76    72    67
V (KT) LAND       80    81    83    86    88    90    90    87    83    80    76    72    67
V (KT) LGE mod    80    81    83    85    88    91    91    89    85    79    74    67    61
Storm Type      TROP  TROP  TROP  TROP  TROP  TROP  TROP  TROP  TROP  TROP  TROP  TROP  TROP

SHEAR (KT)        13    13    10    13    13     5     3     9     9    16    15    21    15
SHEAR ADJ (KT)     7     2    -2    -3    -2    -2    -3    -7    -3     2     2     2    -2
SHEAR DIR         89    82    76    76    94   132   267   264   239   234   212   228   202
SST (C)         28.6  28.5  28.4  28.4  28.2  27.9  27.6  27.4  27.4  27.4  27.5  27.6  27.6
POT. INT. (KT)   151   150   149   148   146   143   139   137   137   137   138   138   137
200 MB T (C)   -51.4 -51.6 -51.8 -51.7 -51.2 -51.7 -50.8 -50.9 -50.6 -51.5 -51.4 -51.5 -51.2
TH_E DEV (C)       8     8     9     8     9     9    10    10    10     9     9     9     8
700-500 MB RH     66    66    67    68    69    64    60    61    62    63    64    64    60
MODEL VTX (KT)    22    21    21    23    24    24    26    26    26    28    28    27    25
850 MB ENV VOR    56    49    38    39    38    36    30    34    42    59    66    70    70
200 MB DIV        59    70    57    34    24    13     9   -15    24    35    83    49    23
700-850 TADV      -4    -4    -5    -3    -1     0     1     1     3    11     7    10     6
LAND (KM)       1596  1474  1353  1251  1149   975   792   629   466   304   180   137   108
LAT (DEG N)     13.1  13.6  14.1  14.5  14.9  15.7  16.5  17.1  17.9  18.8  20.1  20.8  21.1
LONG(DEG W)    141.4 142.4 143.4 144.3 145.1 146.5 148.0 149.4 150.7 152.0 153.2 154.2 155.0
STM SPEED (KT)    11    11    10     9     8     8     8     7     8     8     7     5     4
HEAT CONTENT      11    16    23    27    25    25    28    34    33    34    36    26    23

  FORECAST TRACK FROM OFCI      INITIAL HEADING/SPEED (DEG/KT):285/ 12      CX,CY: -11/  3
  T-12 MAX WIND:  80            PRESSURE OF STEERING LEVEL (MB):  463  (MEAN=581)
  GOES IR BRIGHTNESS TEMP. STD DEV.  50-200 KM RAD:   5.9 (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.  -6.  -9. -11. -14. -16. -16.
  VERTICAL SHEAR MAG    -1.  -2.  -2.  -3.  -2.   1.   3.   4.   4.   3.   1.   0.
  VERTICAL SHEAR ADJ     0.   0.   0.   0.   0.   1.   1.   1.   1.   1.   1.   1.
  VERTICAL SHEAR DIR     1.   1.   3.   3.   5.   3.   2.   0.  -1.  -1.  -1.  -2.
  PERSISTENCE            0.   0.   0.  -1.  -1.  -1.  -1.  -1.  -1.  -1.   0.   0.
  200/250 MB TEMP.       0.  -1.  -2.  -3.  -5.  -7.  -9. -10. -11. -12. -12. -11.
  THETA_E EXCESS         0.   0.   0.   0.   0.   0.   1.   1.   1.   1.   1.   1.
  700-500 MB RH          0.   0.   0.   1.   1.   1.   2.   2.   2.   2.   3.   3.
  MODEL VTX TENDENCY     0.  -1.   1.   1.   2.   5.   5.   6.   9.   9.   8.   5.
  850 MB ENV VORTICITY   0.   0.   0.   0.   0.   1.   1.   1.   1.   2.   3.   3.
  200 MB DIVERGENCE      0.   1.   1.   1.   1.   1.   0.   0.   0.   0.   0.  -1.
  850-700 T ADVEC        0.   0.   0.   0.   0.   0.   0.   0.   0.   0.   1.   1.
  ZONAL STORM MOTION     0.   0.   1.   1.   2.   2.   3.   3.   2.   2.   2.   2.
  STEERING LEVEL PRES    0.   0.   0.   0.  -1.  -1.  -1.  -2.  -2.  -2.  -2.  -2.
  DAYS FROM CLIM. PEAK   0.   0.   0.   0.   0.   0.   0.   1.   2.   2.   2.   2.
  GOES PREDICTORS        2.   3.   4.   4.   5.   5.   5.   4.   4.   3.   3.   3.
  OCEAN HEAT CONTENT     0.   0.   0.   0.   0.   1.   1.   1.   1.   1.   1.   1.
                        ----------------------------------------------------------
  TOTAL CHANGE           1.   3.   6.   8.  10.  10.   7.   3.   0.  -4.  -8. -13.

   ** 2013 E. Pacific RI INDEX EP122015 IGNACIO    08/28/15  00 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) :  12.3 Range: 18.7 to   1.4 Scaled/Wgted Val:  0.4/  0.5
 POT = MPI-VMAX (KT)   :  68.7 Range: 40.3 to 141.7 Scaled/Wgted Val:  0.3/  0.3
 STD DEV OF IR BR TEMP :   5.9 Range: 38.9 to   2.4 Scaled/Wgted Val:  0.9/  0.9
 Heat content (KJ/cm2) :  20.4 Range:  3.6 to  75.9 Scaled/Wgted Val:  0.2/  0.2
 D200 (10**7s-1)       :  48.8 Range:-11.0 to 135.3 Scaled/Wgted Val:  0.4/  0.3
 % area w/pixels <-30 C:  99.0 Range: 41.4 to 100.0 Scaled/Wgted Val:  1.0/  0.5
 850-700 MB REL HUM (%):  69.0 Range: 57.6 to  96.8 Scaled/Wgted Val:  0.3/  0.0
 
 Prob of RI for 25 kt RI threshold=    26% is   1.9 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=    14% is   2.3 times the sample mean( 6.0%)
 Prob of RI for 40 kt RI threshold=    11% is   2.5 times the sample mean( 4.3%)

[dexterlabio]

Seems like Hawaii has a thing with letter "I" hmm..

[Kingarabian]

WTPA43 PHFO 280238
TCDCP3

HURRICANE IGNACIO DISCUSSION NUMBER 13
NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI EP122015
500 PM HST THU AUG 27 2015

ALTHOUGH ITS OVERALL APPEARANCE HAS BECOME A BIT RAGGED IN THE
SATELLITE IMAGERY ON THE WEST SIDE THIS AFTERNOON...DEEP CONVECTION
NEAR THE CENTER OF IGNACIO CONTINUES TO PUSH TOPS ABOVE THE -80C
LEVEL. THE EYE HAS REMAINED CLOUD-FILLED THROUGH THE DAY WITHIN A
CENTRAL DENSE OVERCAST. A 2246 UTC GPM PASS SHOWED THE STRONGEST
CORE CONVECTION SOUTHEAST OF THE CENTER. DVORAK INTENSITY ESTIMATES
CAME IN AT 77 KT FROM SAB AND JTWC...AND 90 KT FROM PHFO. THE 2330
UTC CIMSS ADT ESTIMATE WAS ONCE AGAIN CLOSE TO 80 KT. WITH THE
AVAILABLE ESTIMATES UNCHANGED...THE INITIAL INTENSITY FOR THIS
ADVISORY PACKAGE IS ONCE AGAIN HELD AT 80 KT. A 1932 UTC ASCAT PASS
WAS USED TO HELP REFINE THE WIND RADII.

THE INITIAL MOTION FOR THIS ADVISORY IS 290/11 KT. IGNACIO IS MOVING
SOUTH OF A SUBTROPICAL RIDGE WHICH IS EXPECTED TO WEAKEN. THIS WILL
RESULT IN A SLOWER FORWARD MOTION STARTING TONIGHT. OBJECTIVE AIDS
FOR THIS PACKAGE CONTINUE TO SHOW A GENERAL WEST-NORTHWEST TO
NORTHWEST TRACK THROUGH THE FORECAST PERIOD. THE LATEST GFS HAS
SHIFTED ITS FORECAST TRACK SOUTHWARD A BIT...POSSIBLY DUE TO A
WEAKER PROJECTED CYCLONE IN THE MODEL. THE HWRF HAS SHIFTED
SOUTH AS WELL WITH A WEAKER SYSTEM. THE CURRENT FORECAST MAINTAINS
THE TRACK OF THE PREVIOUS FORECAST AND IS CLOSE TO THE
GFEX THROUGH 72 HOURS...THEN CLOSE TO THE GFS AT 96 AND 120 HOURS.

DESPITE BEING OVER SEA SURFACE TEMPERATURES ABOVE 28C AND LIGHT TO
MODERATE VERTICAL WIND SHEAR...IGNACIO HAS NOT BEEN ABLE STRENGTHEN
TODAY. ACCORDING TO SHIPS GUIDANCE...A WINDOW FOR FURTHER
STRENGTHENING SHOULD EXIST THROUGH 48 HOURS. THE CURRENT FORECAST
REFLECTS THIS...THOUGH WITH A MAXIMUM INTENSITY LOWERED TO 95 KT DUE
TO TODAY/S TRENDS. GRADUAL WEAKENING IS FORECAST BEYOND 48
HOURS...MAINLY DUE TO SLIGHTLY COOLER SEA SURFACE TEMPERATURES AND
INCREASING VERTICAL WIND SHEAR. THIS IS CLOSE TO THE IVCN CONSENSUS
THROUGH 48 HOURS AND DSHP BEYOND 48 HOURS.



FORECAST POSITIONS AND MAX WINDS

INIT 28/0300Z 13.3N 141.9W 80 KT 90 MPH
12H 28/1200Z 14.0N 143.3W 85 KT 100 MPH
24H 29/0000Z 14.8N 145.0W 90 KT 105 MPH
36H 29/1200Z 15.6N 146.5W 95 KT 110 MPH
48H 30/0000Z 16.4N 147.9W 95 KT 110 MPH
72H 31/0000Z 18.0N 150.6W 85 KT 100 MPH
96H 01/0000Z 20.0N 153.5W 75 KT 85 MPH
120H 02/0000Z 22.0N 156.0W 65 KT 75 MPH

$$
FORECASTER KODAMA

[Yellow Evan]

Never though the day would come where the CPHC advs are out before the NHC ones.

[Kingarabian]

Never though the day would come where the CPHC advs are out before the NHC ones.

That's because I'm in class right now and their building is next door. Had a chat with them (kidding). I want to see if they'll let me in and give me a tour of their facility.

[Yellow Evan]

[Yellow Evan]

0z GFS a bit more north like 12z but not any stronger just shows the ridge not as persistent.

[Kingarabian]

0z GFS a bit more north like 12z but not any stronger just shows the ridge not as persistent.

I'm estimating it nearly 7mb stronger this run. NHC and CPHC keep saying that strength is dictating the track.

[Yellow Evan]

Shear per CMISS may be diminishing, though I see no signs of such.

[Kingarabian]

Shear per CMISS may be diminishing, though I see no signs of such.

Mid level shear I'm assuming. Really may think that the Euro solution of a southerly track will eventually materialize. Doesn't look it can get stronger. Maybe maintain strength.

The posts in this forum are NOT official forecast and should not be used as such. They are just the opinion of the poster and may or may not be backed by sound meteorological data. They are NOT endorsed by any professional institution or storm2k.org. For official information, please refer to the NHC and NWS products.

[Yellow Evan]

WTPA43 PHFO 280852
TCDCP3

HURRICANE IGNACIO DISCUSSION NUMBER 14
NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI EP122015
1100 PM HST THU AUG 27 2015

IGNACIO CONTINUES TO RESIST INTENSIFICATION...WITH AN ASYMMETRIC CDO
SATELLITE PRESENTATION AND OUTFLOW WHICH APPEARS A BIT HINDERED
ACROSS ITS EASTERN QUADRANT. THE LLCC LIKELY LIES NEAR THE NORTHWEST
EDGE OF THE CDO...WITH DEEPEST CONVECTION TO ITS SOUTHEAST SHOWING
MINUS 80 DEGREE CELSIUS CLOUD TOP TEMPERATURES. NIGHTTIME CDO
POSITIONAL FIXES FOR THIS SYSTEM WILL BE PROBLEMATIC GIVEN THE LACK
OF A CONSISTENT INFRARED WARM SPOT SO FAR...BUT A TIMELY 0347 UTC
SSMIS PASS GREATLY INCREASES OUR 0600 UTC FIX CONFIDENCE. SUBJECTIVE
DVORAK INTENSITY ESTIMATES RANGE FROM 4.5...77 KT...FROM SAB TO
5.0...90 KT...FROM JTWC AND PHFO. CIMMS ADT DERIVED INTENSITY WAS 80
KT AT 0430 UTC AND THIS WILL BE OUR INITIAL INTENSITY FOR THIS
ADVISORY.

THE INITIAL MOTION FOR THIS ADVISORY IS 295/10 KT...WITH IGNACIO
POSSIBLY STARTING TO SLOW AS IT MOVES ALONG THE SOUTHWESTERN FLANK
OF A WEAKENING SUBTROPICAL RIDGE. TRACK GUIDANCE IS RATHER TIGHTLY
PACKED...SHOWING A CONTINUED MOTION INITIALLY TO THE WEST
NORTHWEST...THEN NORTHWEST...THROUGH THE FIVE DAY FORECAST PERIOD.
ECMWF AND GFS SHIFTED NOTICEABLY TO THE RIGHT...PULLING CONSENSUS TO
THE RIGHT AS WELL. HWRF HAS SHIFTED BACK TO THE RIGHT WHILE ALSO
INTRODUCING A BIT OF A CLOCKWISE CURVE TO THE TRACK BEYOND 48 HOURS.
WE WILL WAIT AT LEAST ONE MORE FORECAST CYCLE TO SEE IF CONSENSUS
SETTLES DOWN BEFORE MAKING ANY BIG CHANGES TO THE FORECAST TRACK.
THAT SAID...THE FORECAST TRACK FOR THIS ADVISORY WAS NUDGED SLIGHTLY
TO THE RIGHT AT 72...96 AND 120 HOURS IN A NOD TO THE GUIDANCE
TREND...WHILE REMAINING ALMOST UNCHANGED THROUGH 48 HOURS.

WHILE A SMALL AMOUNT OF EASTERLY SHEAR IS EVIDENT IN SATELLITE
LOOP...AND PRESENT IN SHIPS INTENSITY GUIDANCE...IGNACIO REMAINS IN
A RATHER FRIENDLY ENVIRONMENT WITH SSTS IN EXCESS OF 28 DEGREES
CELSIUS. SHIPS GUIDANCE CONTINUES TO SHOW SLOW INTENSIFICATION TO
ABOUT 95 KT AT 48 HOURS...FOLLOWED BY A WEAKENING TREND AFTERWARDS
AS THIS SYSTEM MOVES ACROSS SLIGHTLY COOLER WATER AND ENCOUNTERS
MORE SIGNIFICANT SHEAR. THE INTENSITY FORECAST FOR THIS ADVISORY
FOLLOWS THIS TREND...REPRESENTING LITTLE OR NO CHANGE FROM LAST
TIME. WHILE FUTURE FORECASTS MAY CHANGE...THIS ONE DEPICTS THE
CENTER OF IGNACIO PASSING QUITE CLOSE TO BUT JUST NORTHEAST OF THE
MAIN HAWAIIAN ISLANDS AS A HURRICANE EARLY NEXT WEEK.

FORECAST POSITIONS AND MAX WINDS

INIT 28/0900Z 13.9N 143.1W 80 KT 90 MPH
12H 28/1800Z 14.5N 144.5W 85 KT 100 MPH
24H 29/0600Z 15.4N 146.1W 90 KT 105 MPH
36H 29/1800Z 16.2N 147.6W 95 KT 110 MPH
48H 30/0600Z 17.1N 149.1W 95 KT 110 MPH
72H 31/0600Z 18.9N 151.7W 85 KT 100 MPH
96H 01/0600Z 20.9N 154.3W 75 KT 85 MPH
120H 02/0600Z 23.0N 156.7W 65 KT 75 MPH

$$
FORECASTER POWELL

[Yellow Evan]

Code: Select all

                    * EAST PACIFIC SHIPS INTENSITY FORECAST          *
                    * IR SAT DATA AVAILABLE,       OHC AVAILABLE     *
                    *  IGNACIO     EP122015  08/28/15  12 UTC        *

TIME (HR)          0     6    12    18    24    36    48    60    72    84    96   108   120
V (KT) NO LAND    80    82    86    89    93    96    96    96    88    85    79    76    73
V (KT) LAND       80    82    86    89    93    96    96    96    88    85    79    76    73
V (KT) LGE mod    80    82    85    88    90    94    95    90    83    77    70    64    59
Storm Type      TROP  TROP  TROP  TROP  TROP  TROP  TROP  TROP  TROP  TROP  TROP  TROP  TROP

SHEAR (KT)         9     9     6     4     2     4     4     5    12    14    18    22    25
SHEAR ADJ (KT)     0    -2    -4    -2    -2    -5    -3     1     4     1     3     0     0
SHEAR DIR         76    78    84    83    92   335   271   199   239   214   235   222   248
SST (C)         28.5  28.4  28.2  28.1  27.9  27.6  27.4  27.3  27.4  27.5  27.5  27.3  27.2
POT. INT. (KT)   150   148   146   145   143   139   137   136   137   138   138   136   134
200 MB T (C)   -51.7 -51.8 -51.2 -51.1 -51.4 -50.8 -50.9 -50.7 -51.1 -51.1 -51.4 -50.9 -51.6
TH_E DEV (C)       8     8     9     9     9    10    10    10     9     9     9     9     8
700-500 MB RH     65    66    66    66    63    60    58    60    62    62    59    58    58
MODEL VTX (KT)    22    23    24    24    26    27    28    30    28    30    28    29    28
850 MB ENV VOR    47    40    39    45    41    42    44    58    64    81    61    65    70
200 MB DIV        55    39    26    29    18    14     3    41    34    43    35    36    16
700-850 TADV      -4    -3    -1     0     0     2     1     5     9     9     6     9     9
LAND (KM)       1363  1259  1154  1062   970   782   595   431   285   165   136   158   205
LAT (DEG N)     13.9  14.4  14.8  15.2  15.6  16.5  17.4  18.3  19.2  20.2  21.3  22.4  23.3
LONG(DEG W)    143.4 144.3 145.1 145.8 146.6 148.1 149.6 150.9 152.1 153.4 154.8 156.0 157.0
STM SPEED (KT)    10     9     8     8     8     8     8     7     8     8     8     7     6
HEAT CONTENT      23    29    29    28    29    28    35    30    32    36    25    23    24

  FORECAST TRACK FROM OFCI      INITIAL HEADING/SPEED (DEG/KT):290/ 10      CX,CY:  -8/  3
  T-12 MAX WIND:  80            PRESSURE OF STEERING LEVEL (MB):  464  (MEAN=581)
  GOES IR BRIGHTNESS TEMP. STD DEV.  50-200 KM RAD:   6.7 (MEAN=14.5)
  % GOES IR PIXELS WITH T < -20 C    50-200 KM RAD:  99.0 (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.   1.   1.   0.  -3.  -7. -10. -12. -14. -16. -17.
  VERTICAL SHEAR MAG     0.   0.   0.   1.   4.   6.   7.   8.   7.   5.   3.   0.
  VERTICAL SHEAR ADJ     0.   0.   1.   1.   2.   2.   2.   1.   1.   1.   1.   1.
  VERTICAL SHEAR DIR     1.   1.   2.   3.   3.   2.   1.   1.   0.   0.   0.   1.
  PERSISTENCE            0.   0.   0.  -1.  -1.  -1.  -1.  -1.  -1.  -1.   0.   0.
  200/250 MB TEMP.       0.  -1.  -2.  -3.  -5.  -7.  -9. -10. -11. -11. -11. -11.
  THETA_E EXCESS         0.   0.   0.   0.   0.   1.   1.   1.   1.   1.   1.   1.
  700-500 MB RH          0.   0.   0.   1.   1.   1.   1.   2.   2.   2.   2.   2.
  MODEL VTX TENDENCY     0.   1.   1.   4.   6.   8.  12.   9.  11.   9.  10.   9.
  850 MB ENV VORTICITY   0.   0.   0.   0.   0.   1.   1.   2.   2.   3.   4.   5.
  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.   1.   2.
  ZONAL STORM MOTION     0.   0.   0.   1.   1.   1.   1.   1.   1.   1.   1.   1.
  STEERING LEVEL PRES    0.   0.   0.   0.  -1.  -1.  -1.  -2.  -2.  -2.  -2.  -2.
  DAYS FROM CLIM. PEAK   0.   0.   0.   0.   0.   0.   0.   1.   2.   2.   2.   2.
  GOES PREDICTORS        1.   3.   3.   4.   5.   5.   5.   4.   4.   3.   3.   3.
  OCEAN HEAT CONTENT     0.   0.   0.   1.   1.   2.   1.   1.   2.   2.   1.   1.
                        ----------------------------------------------------------
  TOTAL CHANGE           2.   6.   9.  13.  16.  16.  16.   8.   5.  -1.  -4.  -7.

   ** 2013 E. Pacific RI INDEX EP122015 IGNACIO    08/28/15  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) :   6.2 Range: 18.7 to   1.4 Scaled/Wgted Val:  0.7/  1.0
 POT = MPI-VMAX (KT)   :  66.1 Range: 40.3 to 141.7 Scaled/Wgted Val:  0.3/  0.3
 STD DEV OF IR BR TEMP :   6.7 Range: 38.9 to   2.4 Scaled/Wgted Val:  0.9/  0.9
 Heat content (KJ/cm2) :  27.6 Range:  3.6 to  75.9 Scaled/Wgted Val:  0.3/  0.3
 D200 (10**7s-1)       :  33.4 Range:-11.0 to 135.3 Scaled/Wgted Val:  0.3/  0.2
 % area w/pixels <-30 C:  97.0 Range: 41.4 to 100.0 Scaled/Wgted Val:  0.9/  0.5
 850-700 MB REL HUM (%):  67.8 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=    25% is   2.9 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   3.3 times the sample mean( 4.3%)

[Alyono]

seeing signs of the hawaii shear

[cycloneye]

HURRICANE IGNACIO DISCUSSION NUMBER 15
NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI EP122015
500 AM HST FRI AUG 28 2015

OVERALL SATELLITE PRESENTATION FOR IGNACIO HAS CHANGED LITTLE
OVERNIGHT...WITH AN OBLONG 180 NM WIDE CDO HIDING THE LLCC. A VERY
COLD MINUS 90 DEGREE CELSIUS CONVECTIVE TOP POPPED UP JUST SOUTH OF
THE SUSPECTED CENTER WITHIN THE PAST FEW HOURS...WHILE THE FIRST
GOOD HINT AT A CONSISTENT WARM SPOT IS NOTED BEGINNING WITH 1300 UTC
IMAGERY. AN 1130 UTC AMSU PASS ADDS CONFIDENCE TO THE 1200 UTC
POSITIONAL FIX. SUBJECTIVE DVORAK SATELLITE INTENSITY ESTIMATES
RANGED ONCE AGAIN FROM 4.5...77 KT...FROM SAB TO 5.0...90 KT FROM
JTWC AND PHFO. UW-CIMSS ADT SHOWS AN UNCHANGING 80 KT AND...GIVEN
THE ALMOST STEADY STATE SATELLITE PRESENTATION...WE WILL MAKE 80 KT
OUR INITIAL INTENSITY FOR THIS ADVISORY.

IGNACIO CONTINUES TO SLIDE WEST NORTHWESTWARD ALONG THE SOUTHEAST
FLANK OF A WEAKENING SUBTROPICAL RIDGE. INITIAL MOTION FOR THIS
ADVISORY IS SET AT 290/09 KT...INDICATING A SLIGHT DECREASE IN
FORWARD SPEED OVER THE PAST 12 HOURS. TRACK GUIDANCE REMAINS TIGHTLY
PACKED...GENERALLY SHOWING A CONTINUED MOTION INITIALLY TOWARD THE
WEST NORTHWEST...THEN NORTHWEST...THROUGH THE FIVE DAY FORECAST
PERIOD. GFS SHIFTED SLIGHTLY TO THE LEFT AT 120 HOURS AND
BEYOND...BUT WAS NEARLY UNCHANGED ELSEWHERE ALONG THE TRACK.
CONSENSUS GUIDANCE IS ALSO ALMOST UNCHANGED SINCE THE LAST ECMWF RUN
WAS AT 0000 UTC. IN CONTRAST...HWRF AND GFDL CONTINUE SHIFTING
NOTICEABLY TO THE RIGHT...WITH HWRF NOW TURNING IGNACIO SHARPLY
NORTHWARD BEYOND 72 HOURS. THE FORECAST TRACK FOR THIS ADVISORY IS
UNCHANGED FROM THE PREVIOUS ONE...FOLLOWING THE CONSENSUS ARC BUT
REMAINING ON THE LEFT EDGE OF THE GUIDANCE ENVELOPE.

SHIPS GUIDANCE SHOWS THE WINDOW FOR SYSTEM INTENSIFICATION CLOSING
AFTER 36 HOURS...WITH SLIGHTLY COOLER SSTS AND INCREASING SHEAR
TAKING A STEADY TOLL ON INTENSITY AFTER 48 HOURS. THAT
SAID...IGNACIO IS IN A FRIENDLY ENVIRONMENT RIGHT NOW...WITH LOW
SHEAR AND SSTS ABOVE 28 DEGREES CELSIUS. FOLLOWING THE SHIPS
GUIDANCE TREND...IGNACIO IS FORECAST TO SLOWLY STRENGTHEN TO 95 KT
AT 36 HOURS...MAINTAIN THAT STRENGTH THROUGH 48 HOURS...THEN
STEADILY WEAKEN THROUGH THE REST OF THE FORECAST PERIOD. TO STAY IN
LINE WITH SHIPS...THE RATE OF WEAKENING WAS DECREASED SLIGHTLY FOR
THIS ADVISORY...KEEPING IGNACIO AT 70 KT AT 120 HOURS. THIS TREND
ALSO CLOSELY FOLLOWS HWRF...BUT IS WEAKER THAN GFDL. THE FORECAST
HAS THE CENTER OF IGNACIO PASSING CLOSE TO...BUT JUST NORTHEAST
OF...THE MAIN HAWAIIAN ISLANDS AS A HURRICANE EARLY NEXT WEEK.

FORECAST POSITIONS AND MAX WINDS

INIT 28/1500Z 14.1N 143.8W 80 KT 90 MPH
12H 29/0000Z 14.7N 145.1W 85 KT 100 MPH
24H 29/1200Z 15.6N 146.7W 90 KT 105 MPH
36H 30/0000Z 16.5N 148.1W 95 KT 110 MPH
48H 30/1200Z 17.3N 149.5W 90 KT 105 MPH
72H 31/1200Z 19.2N 152.2W 80 KT 90 MPH
96H 01/1200Z 21.2N 154.7W 75 KT 85 MPH
120H 02/1200Z 23.3N 157.1W 70 KT 80 MPH

$$
FORECASTER POWELL

[Alyono]

the models may not be considering the disturbance south of Hawaii

[Kingarabian]

the models may not be considering the disturbance south of Hawaii

As a threat or in terms of Ignacio's track?

12z GFS more north.

[Alyono]

this looks to be running into the Hawaiian shear already

[Yellow Evan]

this looks to be running into the Hawaiian shear already

SHIPS lowers the shear at upper-levels. My only issue in the short-term is mid-level shear.

[Alyono]

the storm has transitioning from a CCC to a banding pattern

[Kingarabian]

Doubt recon will find an 80kt storm at this rate.