EPAC: IGNACIO - Post-Tropical

[Kingarabian]

The hurricane hunters must be licking their chops to finally fix a major hurricane in the central pacific.

[Extratropical94]

Ignacio is looking pretty healthy for a T4.0 hurricane, although it might be running into a slightly drier environment soon.

[Yellow Evan]

Seems to be making a run at major.

[Yellow Evan]

TXPN27 KNES 291204
TCSCNP

A. 12E (IGNACIO)

B. 29/1130Z

C. 15.6N

D. 146.0W

E. ONE/GOES-W

F. T5.0/5.0/D0.5/24HRS

G. IR/EIR

H. REMARKS...AFTER A PERIOD OF WEAKENING SYSTEM HAS ORGANIZED AND
REFORMED AN OFF WHITE EYE EMBEDDED AND SURROUNDED BY LIGHT GRAY FOR A
DT=5.0. MET ON STANDARD CURVE WOULD BE 5.5 BUT PAT=5.0. FT IS BASED ON DT.

I. ADDL POSITIONS

NIL


...SWANSON

[Alyono]

for what it is worth, GDDL and HWRF have shifted closer

[Yellow Evan]

Didn't expect this.


EP, 12, 2015082912, , BEST, 0, 157N, 1462W, 100, 961, HU, 34, NEQ, 90, 70, 80, 80, 1008, 240, 20, 0, 0, E, 0, , 0, 0, IGNACIO, D,
EP, 12, 2015082912, , BEST, 0, 157N, 1462W, 100, 961, HU, 50, NEQ, 50, 40, 40, 35, 1008, 240, 20, 0, 0, E, 0, , 0, 0, IGNACIO, D,
EP, 12, 2015082912, , BEST, 0, 157N, 1462W, 100, 961, HU, 64, NEQ, 30, 30, 30, 30, 1008, 240, 20, 0, 0, E, 0, , 0, 0, IGNACIO, D,

[Ntxw]

Major hurricane ignacio

[Yellow Evan]

----- Current Analysis -----
Date : 29 AUG 2015 Time : 130000 UTC
Lat : 15:50:21 N Lon : 146:18:24 W


CI# /Pressure/ Vmax
5.9 / 950.6mb/112.4kt


Final T# Adj T# Raw T#
5.9 5.9 6.5

Estimated radius of max. wind based on IR : 20 km

Center Temp : +10.1C Cloud Region Temp : -69.5C

Scene Type : EYE

[Yellow Evan]

Ignacio is annular.

Code: Select all

                    * EAST PACIFIC SHIPS INTENSITY FORECAST          *
                    * IR SAT DATA AVAILABLE,       OHC AVAILABLE     *
                    *  IGNACIO     EP122015  08/29/15  12 UTC        *

TIME (HR)          0     6    12    18    24    36    48    60    72    84    96   108   120
V (KT) NO LAND   100   105   108   108   103    96    82    74    65    64    61    60    57
V (KT) LAND      100   105   108   108   103    96    82    74    65    64    61    60    57
V (KT) LGE mod   100   105   106   104   101    91    79    71    63    58    55    54    53
Storm Type      TROP  TROP  TROP  TROP  TROP  TROP  TROP  TROP  TROP  TROP  TROP  TROP  TROP

SHEAR (KT)         5     2     3     8    12    10    16    20    21    17    17    18    20
SHEAR ADJ (KT)    -5    -5    -5    -4    -1     3     7     3     0    -1     2     0    -1
SHEAR DIR        309   329   279   257   257   236   242   206   218   209   225   238   260
SST (C)         27.9  27.7  27.5  27.4  27.3  27.3  27.3  27.5  27.4  27.2  27.2  27.3  27.1
POT. INT. (KT)   142   140   138   137   136   136   136   138   138   135   135   136   133
200 MB T (C)   -51.6 -51.6 -51.0 -50.9 -51.1 -50.8 -51.4 -51.4 -51.7 -51.2 -51.2 -50.8 -51.0
TH_E DEV (C)      10    10    10    10    10    10     9     9     8     8     8     8     8
700-500 MB RH     62    61    61    59    60    62    63    63    64    62    63    63    63
MODEL VTX (KT)    23    24    24    25    23    26    24    25    24    25    25    26    25
850 MB ENV VOR    35    34    34    36    29    50    54    56    58    60    50    50    48
200 MB DIV        22    20    16    12    17    26    12    43    37    29    19    17    12
700-850 TADV       0     1     4     6     7     6     6    12     9     7     4    10     9
LAND (KM)       1004   912   821   731   642   475   335   218   193   206   265   316   400
LAT (DEG N)     15.7  16.2  16.7  17.2  17.7  18.5  19.5  20.5  21.7  22.8  23.9  24.9  25.8
LONG(DEG W)    146.2 146.9 147.6 148.3 149.0 150.4 151.6 153.0 154.4 155.8 157.0 158.3 159.5
STM SPEED (KT)     8     8     8     8     8     8     8     9     9     8     8     7     7
HEAT CONTENT      28    28    27    28    34    28    26    30    19    19    17    11     9

  FORECAST TRACK FROM OFCI      INITIAL HEADING/SPEED (DEG/KT):300/  7      CX,CY:  -5/  4
  T-12 MAX WIND:  80            PRESSURE OF STEERING LEVEL (MB):  587  (MEAN=581)
  GOES IR BRIGHTNESS TEMP. STD DEV.  50-200 KM RAD:   8.2 (MEAN=14.5)
  % GOES IR PIXELS WITH T < -20 C    50-200 KM RAD:  95.0 (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         -1.  -2.  -4.  -5. -11. -17. -22. -27. -31. -35. -37. -39.
  VERTICAL SHEAR MAG     0.   1.   1.   0.   1.   0.  -1.  -2.  -3.  -4.  -6.  -8.
  VERTICAL SHEAR ADJ     0.   1.   1.   2.   1.   1.   0.   0.   0.   0.   0.   0.
  VERTICAL SHEAR DIR     0.  -1.  -2.  -2.  -4.  -5.  -6.  -6.  -5.  -4.  -3.  -1.
  PERSISTENCE            5.   8.   8.   7.   5.   3.   1.   0.   0.   0.  -1.  -1.
  200/250 MB TEMP.       0.  -1.  -2.  -3.  -5.  -7.  -8.  -9. -10.  -9.  -9.  -9.
  THETA_E EXCESS         0.   0.   1.   1.   1.   1.   1.   1.   1.   1.   1.   0.
  700-500 MB RH          0.   0.   0.   0.   1.   1.   1.   1.   2.   2.   2.   2.
  MODEL VTX TENDENCY     0.   1.   1.   1.   4.   1.   3.   2.   4.   3.   5.   3.
  850 MB ENV VORTICITY   0.   0.   0.   0.   0.   1.   1.   1.   2.   3.   3.   3.
  200 MB DIVERGENCE      0.   0.   0.   0.   0.   0.   0.   0.   0.   0.   0.   0.
  850-700 T ADVEC        0.   0.   0.   0.  -1.  -1.  -1.  -1.  -1.   0.   1.   3.
  ZONAL STORM MOTION     0.   0.   0.   0.  -1.  -1.  -1.  -1.  -1.  -1.  -1.  -1.
  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.   1.   2.   2.   2.
  GOES PREDICTORS        1.   1.   1.   2.   2.   3.   4.   3.   4.   4.   4.   4.
  OCEAN HEAT CONTENT     0.   0.   1.   1.   1.   1.   1.   1.   1.   1.   1.   0.
                        ----------------------------------------------------------
  TOTAL CHANGE           5.   8.   8.   3.  -4. -18. -26. -35. -36. -39. -40. -43.

   ** 2013 E. Pacific RI INDEX EP122015 IGNACIO    08/29/15  12 UTC **
           ( 30 KT OR MORE MAX WIND INCREASE IN NEXT 24 HR)
 
 12 HR PERSISTENCE (KT):  20.0 Range:-22.0 to  38.5 Scaled/Wgted Val:  0.7/  1.5
 850-200 MB SHEAR (KT) :   6.0 Range: 18.7 to   1.4 Scaled/Wgted Val:  0.7/  1.1
 POT = MPI-VMAX (KT)   :  38.9 Range: 40.3 to 141.7 Scaled/Wgted Val:  0.0/  0.0
 STD DEV OF IR BR TEMP :   8.2 Range: 38.9 to   2.4 Scaled/Wgted Val:  0.8/  0.9
 Heat content (KJ/cm2) :  29.0 Range:  3.6 to  75.9 Scaled/Wgted Val:  0.4/  0.3
 D200 (10**7s-1)       :  17.4 Range:-11.0 to 135.3 Scaled/Wgted Val:  0.2/  0.1
 % area w/pixels <-30 C:  93.0 Range: 41.4 to 100.0 Scaled/Wgted Val:  0.9/  0.4
 850-700 MB REL HUM (%):  67.0 Range: 57.6 to  96.8 Scaled/Wgted Val:  0.2/  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=     3% is   0.3 times the sample mean( 8.7%)
 Prob of RI for 35 kt RI threshold=     2% is   0.3 times the sample mean( 6.0%)
 Prob of RI for 40 kt RI threshold=     1% is   0.3 times the sample mean( 4.3%)

[CrazyC83]

Hawaii really has to watch this one...although stronger means more poleward?

[Extratropical94]

TS Watch for Hawaii

HURRICANE IGNACIO ADVISORY NUMBER 19
NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI EP122015
500 AM HST SAT AUG 29 2015

...IGNACIO RAPIDLY INTENSIFIES TO A MAJOR HURRICANE...


SUMMARY OF 500 AM HST...1500 UTC...INFORMATION
----------------------------------------------
LOCATION...15.9N 146.5W
ABOUT 625 MI...1005 KM ESE OF HILO HAWAII
ABOUT 835 MI...1340 KM ESE OF HONOLULU HAWAII
MAXIMUM SUSTAINED WINDS...115 MPH...185 KM/H
PRESENT MOVEMENT...WNW OR 300 DEGREES AT 8 MPH...13 KM/H
MINIMUM CENTRAL PRESSURE...961 MB...28.38 INCHES


WATCHES AND WARNINGS
--------------------
CHANGES WITH THIS ADVISORY...

A TROPICAL STORM WATCH HAS BEEN ISSUED FOR HAWAII COUNTY.

SUMMARY OF WATCHES AND WARNINGS IN EFFECT...

A TROPICAL STORM WATCH IS IN EFFECT FOR...
* HAWAII COUNTY

A TROPICAL STORM WATCH MEANS THAT TROPICAL STORM CONDITIONS ARE
POSSIBLE WITHIN THE WATCH AREA...GENERALLY WITHIN 48 HOURS.

INTERESTS ELSEWHERE IN THE MAIN HAWAIIAN ISLANDS SHOULD CONTINUE TO
CLOSELY MONITOR THE PROGRESS OF IGNACIO. WATCHES MAY BE REQUIRED
FOR ADDITIONAL ISLANDS LATER TODAY OR TONIGHT.

FOR STORM INFORMATION SPECIFIC TO YOUR AREA...PLEASE MONITOR
PRODUCTS ISSUED BY THE NATIONAL WEATHER SERVICE OFFICE IN
HONOLULU HAWAII.


DISCUSSION AND 48-HOUR OUTLOOK
------------------------------
AT 500 AM HST...1500 UTC...THE CENTER OF HURRICANE IGNACIO WAS
LOCATED NEAR LATITUDE 15.9 NORTH...LONGITUDE 146.5 WEST. IGNACIO IS
MOVING TOWARD THE WEST-NORTHWEST NEAR 8 MPH...13 KM/H...AND THIS
GENERAL MOTION IS EXPECTED TO CONTINUE OVER THE NEXT COUPLE OF
DAYS. ON THE FORECAST TRACK...THE OUTER WINDS OF IGNACIO COULD
AFFECT THE BIG ISLAND OF HAWAII BY EARLY MONDAY.

MAXIMUM SUSTAINED WINDS ARE NEAR 115 MPH...185 KM/H...WITH HIGHER
GUSTS. IGNACIO IS A CATEGORY THREE HURRICANE ON THE SAFFIR-SIMPSON
HURRICANE WIND SCALE. SOME ADDITIONAL STRENGTHENING IS FORECAST
TODAY...FOLLOWED BY GRADUAL WEAKENING ON SUNDAY AND MONDAY.

HURRICANE FORCE WINDS EXTEND OUTWARD UP TO 35 MILES...55 KM...FROM
THE CENTER...AND TROPICAL STORM FORCE WINDS EXTEND OUTWARD UP TO 105
MILES...165 KM.

THE ESTIMATED MINIMUM CENTRAL PRESSURE IS 961 MB...28.38 INCHES.


HAZARDS AFFECTING LAND
----------------------
WIND...TROPICAL STORM CONDITIONS ARE POSSIBLE ON THE BIG ISLAND OF
HAWAII ON MONDAY.

RAINFALL...TOTAL RAINFALL AMOUNTS OF 2 TO 4 INCHES...WITH ISOLATED
MAXIMUM AMOUNTS NEAR 6 INCHES MAINLY IN AREAS OF HIGHER TERRAIN...
ARE POSSIBLE IN THE WATCH AREA.

SURF...LARGE SWELLS GENERATED BY IGNACIO WILL ARRIVE ALONG EAST AND
SOUTHEAST FACING SHORES OF THE MAIN HAWAIIAN ISLANDS OVER THE NEXT
SEVERAL DAYS. RESULTANT SURF WILL BE LARGE AND POTENTIALLY
LIFE-THREATENING...ESPECIALLY ON THE BIG ISLAND LATER THIS WEEKEND
AND EARLY NEXT WEEK.


NEXT ADVISORY
-------------
NEXT INTERMEDIATE ADVISORY...800 AM HST.
NEXT COMPLETE ADVISORY...1100 AM HST.

$$

FORECASTER BIRCHARD

[Alyono]

not annular at all. Banding very evident

[Yellow Evan]

WTPA43 PHFO 291500
TCDCP3

HURRICANE IGNACIO DISCUSSION NUMBER 19
NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI EP122015
500 AM HST SAT AUG 29 2015

THE SATELLITE PRESENTATION OF IGNACIO HAS IMPROVED DRAMATICALLY
OVER THE PAST SEVERAL HOURS...AND THE HURRICANE HAS RAPIDLY
INTENSIFIED SINCE THE PREVIOUS ADVISORY. THE EYE OF THE HURRICANE
HAS BEEN PERSISTENT AND WARMING IN INFRARED IMAGERY...WHILE
SURROUNDING COLD CLOUD TOPS NOW NEARLY ENCIRCLE THE CENTER. THE
INCREASED GRADIENT IN TEMPERATURES BETWEEN THE EYE AND EYE WALL LED
TO A SIGNIFICANT INCREASE IN SUBJECTIVE AND OBJECTIVE DVORAK DATA-T
NUMBERS. THESE SATELLITE-BASED INTENSITY ESTIMATES NOW RANGE FROM
T5.0/90 KT TO T6.0/115 KT...AND SUPPORT INCREASING THE INITIAL
INTENSITY TO 100 KT FOR THIS ADVISORY...WHICH MAKES IGNACIO A
CATEGORY 3 MAJOR HURRICANE.

THE INITIAL MOTION ESTIMATE FOR THIS ADVISORY IS 300/07 KT...WITH
THE EYE WOBBLING ALONG ON A TRACK SLIGHTLY SLOWER...AND TO THE LEFT
OF...THE PREVIOUS FORECAST. DESPITE THIS...THE TRACK FORECAST
PHILOSOPHY HAS CHANGED LITTLE...WITH IGNACIO FORECAST TO TRACK
GENERALLY NORTHWESTWARD TOWARD A BREAK IN A MID-LEVEL RIDGE THAT IS
CENTERED TO THE DISTANT NORTHEAST. THE TRACK GUIDANCE IS ONCE AGAIN
TIGHTLY CLUSTERED...BUT THE TVCN CONSENSUS HAS SHIFTED CLOSER TO THE
NEARLY UNCHANGED OFFICIAL FORECAST TRACK...AS LATEST ITERATIONS
OF BOTH THE GFS AND GFDL HAVE SHIFTED TOWARD THE LEFT.

WATER VAPOR IMAGERY...AS WELL AS UPPER-AIR AND UW-CIMSS ANALYSES...
INDICATE THAT IGNACIO CONTINUES TO TRAVERSE AN AREA OF VERY WEAK
SHEAR...IN A COL BETWEEN UPPER-LEVEL RIDGES CENTERED TO THE
EAST-NORTHEAST...AND TO THE WEST. THIS SETUP IS PROVIDING
FAVORABLE OUTFLOW CHANNELS FOR THE HURRICANE...ESPECIALLY IN THE
NORTHERN SEMICIRCLE. IN THE SHORT-TERM...SUFFICIENTLY WARM WATER
TEMPERATURES AND LIGHT SHEAR LIE ALONG THE FORECAST TRACK...AND THE
OFFICIAL FORECAST CLOSELY FOLLOWS TRENDS PRESENTED BY THE INTENSITY
CONSENSUS IVCN IN ANTICIPATING ADDITIONAL STRENGTHENING TODAY. AFTER
THE FIRST 24 HOURS...SOUTHWESTERLY SHEAR IS FORECAST TO GRADUALLY
INCREASE...WITH ONLY SMALL CHANGES IN UNDERLYING WATER TEMPERATURES
AND OCEAN HEAT CONTENT. THE FACT THAT IGNACIO MAY BECOME ANNULAR
COMPLICATES THE INTENSITY FORECAST AS IT MAY BECOME LESS PRONE TO
WEAKENING DUE TO NEGATIVE ENVIRONMENTAL FACTORS. ADDITIONALLY...
SHORT TERM FLUCTUATIONS IN INTENSITY REMAIN POSSIBLE DUE TO
DIFFICULT TO FORECAST EYE WALL REPLACEMENT CYCLES. ASIDE FROM THESE
COMPLICATING FACTORS...A GRADUAL WEAKENING TREND FORECAST TO
COMMENCE ON SUNDAY IS EXPECTED TO PERSIST THROUGH DAY 5.

WHILE THE FORECAST TRACK KEEPS THE CENTER OF IGNACIO NORTHEAST OF
THE MAIN HAWAIIAN ISLANDS...UNCERTAINTY SURROUNDING THE TRACK AND
INTENSITY FORECAST NECESSITATES THE ISSUANCE OF A TROPICAL STORM
FOR THE BIG ISLAND. ADDITIONAL ISLANDS MAY NEED TO BE ADDED TO THE
WATCH LATER TODAY.

ANOTHER RECONNAISSANCE FLIGHT BY THE HURRICANE HUNTERS IS SCHEDULED
TO INVESTIGATE IGNACIO LATER THIS MORNING...FOLLOWED BY 12 HOURLY
FLIGHTS UNTIL SUNDAY MORNING...AFTER WHICH TIME FLIGHTS WILL OCCUR
AT 6 HOURLY INTERVALS.


FORECAST POSITIONS AND MAX WINDS

INIT 29/1500Z 15.9N 146.5W 100 KT 115 MPH
12H 30/0000Z 16.6N 147.6W 110 KT 125 MPH
24H 30/1200Z 17.6N 149.0W 105 KT 120 MPH
36H 31/0000Z 18.6N 150.3W 100 KT 115 MPH
48H 31/1200Z 19.7N 151.9W 85 KT 100 MPH
72H 01/1200Z 21.7N 154.8W 75 KT 85 MPH
96H 02/1200Z 24.0N 157.5W 65 KT 75 MPH
120H 03/1200Z 26.5N 160.0W 60 KT 70 MPH

$$

FORECASTER BIRCHARD

[Yellow Evan]

not annular at all. Banding very evident

I recalling reading somewhere that technically banding is not part of the annular criteria per SHIPS.

[Extratropical94]

If the current trend continues and the eye becomes even more symmetrical and surrounded by thick convection, I see Ignacio reaching category 4 strength (115, maybe 120 knots) at 2100Z. Raw ADT values support this and are already at the same level as Jimena's, near T6.5.

The last frame in the sat loop shows major improvements in Ignacio's structure:

[supercane]

Ignacio is annular.

Agree with alyono that this is not really annular. You left out the very end of the SHIPS diagnostic message saying so.

## ANNULAR HURRICANE INDEX (AHI) EP122015 IGNACIO 08/29/15 12 UTC ##
## PASSED SCREENING STEP, MIGHT BE ANNULAR, CALCULATE AHI FROM DISCRIMINANT ANALYSIS ##
## AHI= 1 (AHI OF 100 IS BEST FIT TO ANN. STRUC., 1 IS MARGINAL, 0 IS NOT ANNULAR) ##

It is true that the objective criteria don't include banding, though the 2002 Knaff, Kossin, and DeMaria paper introducing the term annular hurricane states, "the hurricane has little or no convective activity beyond this annulus of convection." See the powerpoint explaining the AHI or the 2008 Knaff et al paper for more details.

[Alyono]

almost looks like it is about to start an eyewall replacement

[Alyono]

12Z MU through 39 hours NE of the 6Z. Becoming more confident this will in fact be a miss

[Kingarabian]

12Z MU through 39 hours NE of the 6Z. Becoming more confident this will in fact be a miss

But it's not a comfortable miss yet. Actually pretty close through 72 hours. Maybe 50 miles off the coast? Maybe it'll shift to the Euros track at 18z.

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.

[Kingarabian]