EPAC: GUILLERMO - Post-Tropical

[Kingarabian]

Surprised the pressure was 974. Pretty low for a storm with its looks and structure.

[Yellow Evan]

Surprised the pressure was 974. Pretty low for a storm with its looks and structure.

Pressure lags wind. This could imply the peak intensity was 90-95 knts.

[Kingarabian]

80kts for initial intensity?

[Yellow Evan]

80kts for initial intensity?

85 knt FL supports 75-80, but SFMR was slighlty lower (peak 70 knts or so). Given the low pressures, there is likely some 75 knt winds of the surface. 75 knt is good.

[Yellow Evan]

WTPA44 PHFO 022044
TCDCP4

HURRICANE GUILLERMO DISCUSSION NUMBER 16
NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI EP092015
1100 AM HST SUN AUG 02 2015

INCREASING NORTHWESTERLY UPPER LEVEL WINDS HAVE BEGUN TO AFFECT
GUILLERMO...AND ITS SATELLITE PRESENTATION HAS BECOME INCREASINGLY
RAGGED THIS MORNING. THE U.S. AIR FORCE 53RD WEATHER RECONNAISSANCE
SQUADRON CONDUCTED ITS FIRST RECONNAISSANCE MISSION...AND THEIR
DATA HAS BEEN CRITICAL IN LOCATING THE CENTER...DETERMINING THE
CURRENT INTENSITY...AND ADJUSTING THE WIND RADII. DVORAK CURRENT
INTENSITY ESTIMATES RANGE FROM A HIGH OF 5.0/90 KT FROM SAB TO
4.5/77 KT FROM HFO...JTWC...AND CIMSS ADT. RECONNAISSANCE FOUND A
MAXIMUM FLIGHT LEVEL WIND IN THE NORTHEAST QUADRANT OF 81
KT...WHICH SUGGESTS A SURFACE WIND OF 73 KT. GIVEN THE UNCERTAINTY
OF WHETHER OR NOT THE MAXIMUM WIND WAS SAMPLED...THE INITIAL
INTENSITY WILL BE LOWERED TO 80 KT...THOUGH THIS IS LIKELY
GENEROUS.

THE INITIAL MOTION IS TOWARD THE WEST-NORTHWEST OR 300 DEGREES AT 9
KT AS GUILLERMO HAS BEGUN TO MAKE A TURN TOWARD THE NORTHWEST. THE
HURRICANE HAS BEEN MOVING TOWARD THE WEST-NORTHWEST ALONG THE
WESTERN END OF A DEEP SUBTROPICAL RIDGE TO THE NORTH AND NORTHEAST.
A WEAKNESS IN THE RIDGE ALOFT IS BEING SLOWLY CARVED OUT NORTH OF
GUILLERMO BY A DEEPENING NORTH PACIFIC UPPER LEVEL TROUGH. IN
RESPONSE...GUILLERMO HAS BEGUN TO SLOWLY MOVE ON A MORE
NORTHWESTWARD TRACK INTO THE BREAK IN THE RIDGE. GUILLERMO IS
EXPECTED TO CONTINUE TO MOVE TOWARD THE NORTHWEST THROUGH THE
FORECAST PERIOD...PLACING IT NEAR THE HAWAIIAN ISLANDS BY WEDNESDAY.
THE UPDATED TRACK HAS BEEN CHANGED LITTLE FROM THE LAST ADVISORY AND
IS NEAR A RATHER TIGHT CLUSTER OF THE RELIABLE DYNAMICAL MODELS AND
THE CONSENSUS MODELS. NOTABLE OUTLIERS DEVIATE ON WEDNESDAY AND
BEYOND. BY WEDNESDAY...THE HRWF TAKES A MUCH WEAKER AND SHALLOWER
GUILLERMO FARTHER SOUTH...AND THE GFDL CARRIES A STRONGER SYSTEM
TO THE NORTH OF MOST GUIDANCE.

WEAKENING IS EXPECTED TO CONTINUE THROUGH THE FORECAST PERIOD. AS
GUILLERMO CONTINUES TO MOVE INTO THE BREAK IN THE MID TO UPPER
LEVEL RIDGE...OUTFLOW WITHIN THE NORTHWEST QUADRANT WILL BECOME
DISRUPTED FURTHER AND VERTICAL WIND SHEAR WILL SLOWLY INCREASE.
GUILLERMO HAS BEEN WEAKENED MORE AGGRESSIVELY COMPARED TO THE LAST
ADVISORY IN LIEU OF RECONNAISSANCE DATA AND THE RECENT SATELLITE
PRESENTATION. THE FORECAST CLOSELY FOLLOWS IVCN AND SHIPS THROUGH 72
HOURS...WITH SHIPS WEAKENING GUILLERMO FASTER ON DAYS FOUR AND FIVE.

AT THIS TIME...IT IS IMPORTANT FOR THOSE IN THE MAIN HAWAIIAN
ISLANDS NOT TO FOCUS TOO CLOSELY ON THE EXACT FORECAST TRACK OF
GUILLERMO. WITH AN AVERAGE 72 HOUR FORECAST TRACK ERROR OF ABOUT
150 STATUTE MILES...IT IS STILL TOO SOON TO DETERMINE WITH CERTAINTY
WHICH ISLANDS MOST LIKELY TO EXPERIENCE THE GREATEST IMPACTS FROM
GUILLERMO. IT IS ALSO IMPORTANT TO NOTE THAT SIGNIFICANT IMPACTS
FROM TROPICAL CYCLONES CAN EXTEND WELL AWAY FROM THE CENTER.

THE NOAA G-IV AIRCRAFT WILL CONDUCT A SYNOPTIC SAMPLING MISSION
NORTH OF GUILLERMO DURING ITS TRANSIT TO HAWAII THIS AFTERNOON.
THIS SAMPLING SHOULD IMPROVE THE MODEL INITIALIZATION OF THE
ENVIRONMENT AFFECTING GUILLERMO. THE NEXT U.S. AIR FORCE MISSION
INTO GUILLERMO IS SCHEDULED FOR THIS EVENING.




FORECAST POSITIONS AND MAX WINDS

INIT 02/2100Z 15.2N 144.1W 80 KT 90 MPH
12H 03/0600Z 15.8N 145.3W 75 KT 85 MPH
24H 03/1800Z 16.6N 147.0W 65 KT 75 MPH
36H 04/0600Z 17.3N 148.7W 60 KT 70 MPH
48H 04/1800Z 17.9N 150.4W 50 KT 60 MPH
72H 05/1800Z 19.5N 153.8W 45 KT 50 MPH
96H 06/1800Z 21.4N 157.1W 35 KT 40 MPH
120H 07/1800Z 23.6N 162.0W 30 KT 35 MPH

$$
FORECASTER WROE

[Kingarabian]

[Yellow Evan]

Ragged eye trying to come back?

[Kingarabian]

Outflow is established everywhere except to the south.

[Kingarabian]

Looks like it could've reintensified somewhat.

[Yellow Evan]

The CDO looks ragged still. Probs a high-end Cat 1.

[Kingarabian]

The CDO looks ragged still. Probs a high-end Cat 1.

It's crazy how bad the CDO looks yet microwave paints a different story.

[Yellow Evan]

The CDO looks ragged still. Probs a high-end Cat 1.

It's crazy how bad the CDO looks yet microwave paints a different story.

Yea. Recon data however suggested a very ragged system.

[Kingarabian]

SAB is @ 5.0 FWIW.

[CrazyC83]

Still since Recon was generous (I'd have gone 70 or 75 kt), I wouldn't raise it back about 80 kt until the next flight.

[Yellow Evan]

Why return to curved band?

TXPN23 KNES 030008
TCSCNP

A. 09E (GUILLERMO)

B. 02/2330Z

C. 15.0N

D. 144.5W

E. THREE/GOES-W

F. T4.0/5.0/W1.0/12HRS

G. IR/EIR/VIS

H. REMARKS...DT OF 4.0 IS BASED ON 1.1 BANDING. MET AND PT ARE 4.0. FT
IS BASED ON DT.

I. ADDL POSITIONS

NIL


...RAMIREZ

[Kingarabian]

Still since Recon was generous (I'd have gone 70 or 75 kt), I wouldn't raise it back about 80 kt until the next flight.

Agreed.

[Yellow Evan]

Eye still looks open. Probs steady state.

[cycloneye]

Down to 75kts.

09E GUILLERMO 150803 0000 15.3N 144.6W EPAC 75 982

[Yellow Evan]

WTPA44 PHFO 030247
TCDCP4

HURRICANE GUILLERMO DISCUSSION NUMBER 17
NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI EP092015
500 PM HST SUN AUG 02 2015

THE SATELLITE PRESENTATION OF GUILLERMO CONTINUES TO SLOWLY
DEGRADE. DEEP CONVECTION IS PULSING AROUND A DIFFICULT TO LOCATE
CENTER WITH THE MOST PERSISTENT COLD TOPS CONFINED TO THE NORTHEAST
QUADRANT. A 2346 UTC SSMI PASS AND A 0013 UTC AMSU PASS WERE HELPFUL
IN DETERMINING A CENTER POSITION. DVORAK CURRENT INTENSITY ESTIMATES
WERE 5.0/90 KT FROM SAB AND 4.5/77 KT FROM HFO AND JTWC...WHILE
FINAL T NUMBERS WERE LOWER AT 4.0 TO 4.5. CIMSS ADT SUGGESTED 70
KT...AND GIVEN RECONNAISSANCE DATA FROM EARLIER IN THE DAY...THE
OFFICIAL INTENSITY HAS BEEN LOWERED TO 75 KT.

THE INITIAL MOTION IS TOWARD THE WEST-NORTHWEST...OR 295 DEGREES...
AT 9 KT. A LOW LEVEL RIDGE SITS ABOUT 1500 NM TO THE NORTHWEST OF
GUILLERMO...WHILE A NORTH PACIFIC UPPER LEVEL TROUGH HAS CARVED OUT
A WEAKNESS IN THE MID TO UPPER LEVEL RIDGE JUST NORTH OF THE
HURRICANE. GUILLERMO WILL CONTINUE TO MOVE ON A SIMILAR BEARING FOR
THE NEXT FEW DAYS INTO THE WEAKNESS ALOFT...TAKING THE SYSTEM NEAR
OR POSSIBLY OVER THE HAWAIIAN ISLANDS ON WEDNESDAY AND THURSDAY.
THE TRACK FORECAST HAS BEEN CHANGED LITTLE FROM THE LAST ADVISORY
AND REMAINS NEAR A RATHER TIGHT CLUSTER OF GFS...ECMWF...AND THE
CONSENSUS MODELS. THE HRWF HAS MOVED BACK SLIGHTLY CLOSER TO THE
CONSENSUS...WHILE THE GFDL CONTINUES TO SEND A STRONGER SYSTEM
NORTHWARD ON WEDNESDAY.

WEAKENING IS EXPECTED TO CONTINUE THROUGH THE FORECAST PERIOD. AS
GUILLERMO CONTINUES TO MOVE INTO THE BREAK IN THE MID TO UPPER
LEVEL RIDGE...OUTFLOW WITHIN THE NORTHWEST QUADRANT WILL BECOME
DISRUPTED FURTHER AND VERTICAL WIND SHEAR WILL SLOWLY INCREASE. THE
RATE OF WEAKENING HAS BEEN CHANGED LITTLE SINCE THE LAST
ADVISORY...AND THE FORECAST CLOSELY FOLLOWS THE ICON...WITH SHIPS
PREDICTING MORE RAPID WEAKENING BEYOND 48 HOURS.

AS GUILLERMO MOVES CLOSER TO HAWAII...WATCHES MAY BE ISSUED AS
EARLY AS MONDAY MORNING FOR PORTIONS OF THE STATE. HOWEVER...IT IS
STILL TOO SOON TO DETERMINE WITH CERTAINTY WHICH ISLANDS ARE MOST
LIKELY TO EXPERIENCE THE GREATEST IMPACTS FROM GUILLERMO. IT IS
ALSO IMPORTANT TO NOTE THAT SIGNIFICANT IMPACTS CAN EXTEND WELL
AWAY FROM THE CENTER.

THE NOAA G-IV JET CONDUCTED A SYNOPTIC MISSION NORTH OF GUILLERMO
EARLIER THIS AFTERNOON. THIS SAMPLING SHOULD IMPROVE THE MODEL
INITIALIZATION OF THE ENVIRONMENT AFFECTING GUILLERMO. THE NEXT
G-IV MISSION IS SCHEDULED FOR TOMORROW MORNING...AND THE NEXT U.S.
AIR FORCE MISSION INTO GUILLERMO IS SCHEDULED FOR THIS EVENING.






FORECAST POSITIONS AND MAX WINDS

INIT 03/0300Z 15.5N 145.0W 75 KT 85 MPH
12H 03/1200Z 16.1N 146.2W 70 KT 80 MPH
24H 04/0000Z 16.9N 147.7W 65 KT 75 MPH
36H 04/1200Z 17.5N 149.5W 60 KT 70 MPH
48H 05/0000Z 18.2N 151.2W 50 KT 60 MPH
72H 06/0000Z 19.9N 154.8W 45 KT 50 MPH
96H 07/0000Z 21.9N 158.5W 35 KT 40 MPH
120H 08/0000Z 24.1N 163.3W 30 KT 35 MPH

$$
FORECASTER WROE

[Kingarabian]

Looks like it weakened more based on a new AMSU pass.

Interesting to see if recon finds a hurricane.