Monthly Archives: July 2015

Hurricane GUILLERMO Forecast Discussion Number 9 2015-07-31 22:58:20

1438397900
Issued at 800 PM PDT FRI JUL 31 2015


000
WTPZ44 KNHC 010258
TCDEP4

HURRICANE GUILLERMO DISCUSSION NUMBER   9
NWS NATIONAL HURRICANE CENTER MIAMI FL       EP092015
800 PM PDT FRI JUL 31 2015

Both microwave and conventional satellite imagery indicate that
Guillermo has not become any better organized during the past
several hours. In fact, the satellite presentation appears to have
deteriorated since earlier today with microwave data showing the
northwestern portion of the eyewall eroding.  Satellite intensity
estimates from TAFB and SAB and the latest objective intensity
estimate from UW-CIMSS ADT suggest that initial intensity remains 90
kt.

Guillermo continues to move rapidly to the west-northwest, with an
initial motion estimate of 285/18 kt. Little change to this motion
is expected for the next 24 hours, with the cyclone remaining to the
south of a mid-level subtropical ridge. Beyond 24 hours to around
72 hours, a deepening mid- to upper-level trough over the central
Pacific is forecast to create a break in the subtropical ridge,
which should cause the tropical cyclone to slow down and turn more
toward the northwest. The spread in the guidance suite increases
beyond 72 hours, but most of the models maintain a general
west-northwestward motion.  The new forecast track is basically an
update of the previous track through 72 hours, and is then nudged
slightly to the right or north of the previous track toward the
multi-model consensus thereafter.

The intensity forecast has become somewhat problematic. The reason
for the recent arrested development is unclear, although it might be
related to dry air entrainment into the northwestern quadrant of the
cyclone. However, there is still the opportunity for Guillermo to
strengthen a bit more during the next 12 to 24 hours, while the
system remains within a low-shear environment and over warm sea
surface temperatures. The new intensity forecast is adjusted
slightly downward to 95 kt at the 12- and 24-hour forecast times.
Thereafter, the cyclone is forecast to move into an upper-level
deformation zone between subtropical ridges to the east and west,
which is a less favorable environment.  Also, sea surface
temperatures gradually cool along the forecast track. We have
followed the previous forecast trend of gradual weakening, which is
in good agreement with the latest SHIPS/LGEM and IVCN consensus
guidance. When Guillermo approaches the Hawaiian Islands, it is
expected to encounter increasing westerly shear, and the new
intensity forecast follows the previous forecast in weakening
Guillermo to tropical storm strength.


FORECAST POSITIONS AND MAX WINDS

INIT  01/0300Z 13.2N 136.1W   90 KT 105 MPH
 12H  01/1200Z 13.7N 138.5W   95 KT 110 MPH
 24H  02/0000Z 14.3N 141.1W   95 KT 110 MPH
 36H  02/1200Z 15.0N 143.2W   90 KT 105 MPH
 48H  03/0000Z 15.8N 145.0W   80 KT  90 MPH
 72H  04/0000Z 17.0N 147.5W   65 KT  75 MPH
 96H  05/0000Z 19.0N 150.5W   60 KT  70 MPH
120H  06/0000Z 20.5N 153.5W   50 KT  60 MPH

$$
Forecaster Beven/Jacobson

http://www.nhc.noaa.gov/text/refresh/MIATCDEP4+shtml/010258.shtml

Hurricane GUILLERMO Forecast Discussion Number 9 2015-07-31 22:57:56

1438397876
Issued at 800 PM PDT FRI JUL 31 2015

ZCZC MIATCDEP4 ALL
TTAA00 KNHC DDHHMM

HURRICANE GUILLERMO DISCUSSION NUMBER   9
NWS NATIONAL HURRICANE CENTER MIAMI FL       EP092015
800 PM PDT FRI JUL 31 2015

Both microwave and conventional satellite imagery indicate that
Guillermo has not become any better organized during the past
several hours. In fact, the satellite presentation appears to have
deteriorated since earlier today with microwave data showing the
northwestern portion of the eyewall eroding.  Satellite intensity
estimates from TAFB and SAB and the latest objective intensity
estimate from UW-CIMSS ADT suggest that initial intensity remains 90
kt.

Guillermo continues to move rapidly to the west-northwest, with an
initial motion estimate of 285/18 kt. Little change to this motion
is expected for the next 24 hours, with the cyclone remaining to the
south of a mid-level subtropical ridge. Beyond 24 hours to around
72 hours, a deepening mid- to upper-level trough over the central
Pacific is forecast to create a break in the subtropical ridge,
which should cause the tropical cyclone to slow down and turn more
toward the northwest. The spread in the guidance suite increases
beyond 72 hours, but most of the models maintain a general
west-northwestward motion.  The new forecast track is basically an
update of the previous track through 72 hours, and is then nudged
slightly to the right or north of the previous track toward the
multi-model consensus thereafter.

The intensity forecast has become somewhat problematic. The reason
for the recent arrested development is unclear, although it might be
related to dry air entrainment into the northwestern quadrant of the
cyclone. However, there is still the opportunity for Guillermo to
strengthen a bit more during the next 12 to 24 hours, while the
system remains within a low-shear environment and over warm sea
surface temperatures. The new intensity forecast is adjusted
slightly downward to 95 kt at the 12- and 24-hour forecast times.
Thereafter, the cyclone is forecast to move into an upper-level
deformation zone between subtropical ridges to the east and west,
which is a less favorable environment.  Also, sea surface
temperatures gradually cool along the forecast track. We have
followed the previous forecast trend of gradual weakening, which is
in good agreement with the latest SHIPS/LGEM and IVCN consensus
guidance. When Guillermo approaches the Hawaiian Islands, it is
expected to encounter increasing westerly shear, and the new
intensity forecast follows the previous forecast in weakening
Guillermo to tropical storm strength.


FORECAST POSITIONS AND MAX WINDS

INIT  01/0300Z 13.2N 136.1W   90 KT 105 MPH
 12H  01/1200Z 13.7N 138.5W   95 KT 110 MPH
 24H  02/0000Z 14.3N 141.1W   95 KT 110 MPH
 36H  02/1200Z 15.0N 143.2W   90 KT 105 MPH
 48H  03/0000Z 15.8N 145.0W   80 KT  90 MPH
 72H  04/0000Z 17.0N 147.5W   65 KT  75 MPH
 96H  05/0000Z 19.0N 150.5W   60 KT  70 MPH
120H  06/0000Z 20.5N 153.5W   50 KT  60 MPH

$$
Forecaster Beven/Jacobson

NNNN

http://www.nhc.noaa.gov/text/refresh/MIATCDEP4+shtml/DDHHMM.shtml

Hurricane GUILLERMO Forecast Advisory Number 9 2015-07-31 22:45:16

1438397116
Issued at 0300 UTC SAT AUG 01 2015


000
WTPZ24 KNHC 010245
TCMEP4

HURRICANE GUILLERMO FORECAST/ADVISORY NUMBER   9
NWS NATIONAL HURRICANE CENTER MIAMI FL       EP092015
0300 UTC SAT AUG 01 2015

THERE ARE NO COASTAL WATCHES OR WARNINGS IN EFFECT.

HURRICANE CENTER LOCATED NEAR 13.2N 136.1W AT 01/0300Z
POSITION ACCURATE WITHIN  20 NM

PRESENT MOVEMENT TOWARD THE WEST-NORTHWEST OR 285 DEGREES AT  17 KT

ESTIMATED MINIMUM CENTRAL PRESSURE  970 MB
MAX SUSTAINED WINDS  90 KT WITH GUSTS TO 110 KT.
64 KT....... 20NE  20SE  15SW  20NW.
50 KT....... 40NE  40SE  30SW  40NW.
34 KT.......100NE 100SE  60SW  90NW.
12 FT SEAS..270NE 210SE 150SW 210NW.
WINDS AND SEAS VARY GREATLY IN EACH QUADRANT.  RADII IN NAUTICAL
MILES ARE THE LARGEST RADII EXPECTED ANYWHERE IN THAT QUADRANT.

REPEAT...CENTER LOCATED NEAR 13.2N 136.1W AT 01/0300Z
AT 01/0000Z CENTER WAS LOCATED NEAR 12.9N 135.5W

FORECAST VALID 01/1200Z 13.7N 138.5W
MAX WIND  95 KT...GUSTS 115 KT.
64 KT... 30NE  25SE  15SW  20NW.
50 KT... 50NE  40SE  40SW  50NW.
34 KT...110NE 100SE  60SW  90NW.

FORECAST VALID 02/0000Z 14.3N 141.1W
MAX WIND  95 KT...GUSTS 115 KT.
64 KT... 30NE  25SE  15SW  20NW.
50 KT... 50NE  40SE  40SW  50NW.
34 KT...110NE 100SE  60SW  90NW.

FORECAST VALID 02/1200Z 15.0N 143.2W
MAX WIND  90 KT...GUSTS 110 KT.
64 KT... 30NE  25SE  15SW  20NW.
50 KT... 50NE  40SE  40SW  50NW.
34 KT...110NE 100SE  60SW  90NW.

FORECAST VALID 03/0000Z 15.8N 145.0W
MAX WIND  80 KT...GUSTS 100 KT.
50 KT... 50NE  40SE  40SW  50NW.
34 KT...110NE 100SE  60SW  90NW.

FORECAST VALID 04/0000Z 17.0N 147.5W
MAX WIND  65 KT...GUSTS  80 KT.
50 KT... 50NE  40SE  40SW  50NW.
34 KT...100NE  90SE  60SW  90NW.

EXTENDED OUTLOOK. NOTE...ERRORS FOR TRACK HAVE AVERAGED NEAR 125 NM
ON DAY 4 AND 150 NM ON DAY 5...AND FOR INTENSITY NEAR 15 KT EACH DAY

OUTLOOK VALID 05/0000Z 19.0N 150.5W
MAX WIND  60 KT...GUSTS  75 KT.

OUTLOOK VALID 06/0000Z 20.5N 153.5W
MAX WIND  50 KT...GUSTS  60 KT.

REQUEST FOR 3 HOURLY SHIP REPORTS WITHIN 300 MILES OF 13.2N 136.1W

NEXT ADVISORY AT 01/0900Z

$$
FORECASTER BEVEN/JACOBSON


http://www.nhc.noaa.gov/text/refresh/MIATCMEP4+shtml/010245.shtml

Hurricane GUILLERMO Public Advisory Number 9 2015-07-31 22:46:18

1438397178
Issued at 800 PM PDT FRI JUL 31 2015

ZCZC MIATCPEP4 ALL
TTAA00 KNHC DDHHMM

BULLETIN
HURRICANE GUILLERMO ADVISORY NUMBER   9
NWS NATIONAL HURRICANE CENTER MIAMI FL       EP092015
800 PM PDT FRI JUL 31 2015

...GUILLERMO MOVING RAPIDLY WEST-NORTHWESTWARD...
...NO LONGER STRENGTHENING...


SUMMARY OF 800 PM PDT...0300 UTC...INFORMATION
----------------------------------------------
LOCATION...13.2N 136.1W
ABOUT 1335 MI...2150 KM ESE OF HILO HAWAII
MAXIMUM SUSTAINED WINDS...105 MPH...165 KM/H
PRESENT MOVEMENT...WNW OR 285 DEGREES AT 20 MPH...31 KM/H
MINIMUM CENTRAL PRESSURE...970 MB...28.65 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 Hurricane Guillermo was
located near latitude 13.2 North, longitude 136.1 West. Guillermo is
moving toward the west-northwest near 20 mph (31 km/h), and this
motion is expected to continue tonight with a gradual decrease in
forward speed on Saturday.

Maximum sustained winds are near 105 mph (165 km/h) with higher
gusts.  Guillermo has not strengthened during the past several
hours. However, some strengthening is possible tonight and Saturday.
Weakening is expected to begin on Sunday.

Hurricane force winds extend outward up to 25 miles (35 km) from the
center and tropical storm force winds extend outward up to 115 miles
(185 km).

The estimated minimum central pressure is 970 mb (28.65 inches).


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


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

$$
Forecaster Beven/Jacobson

NNNN

http://www.nhc.noaa.gov/text/refresh/MIATCPEP4+shtml/DDHHMM.shtml

Summary for Hurricane GUILLERMO (EP4/EP092015) 2015-07-31 22:45:55

1438397155
…GUILLERMO MOVING RAPIDLY WEST-NORTHWESTWARD… …NO LONGER STRENGTHENING…
As of 8:00 PM PDT Fri Jul 31
the center of GUILLERMO was located near 13.2, -136.1
with movement WNW at 20 mph.
The minimum central pressure was 970 mb
with maximum sustained winds of about 105 mph.

http://www.nhc.noaa.gov/text/refresh/MIATCPEP4+shtml/DDHHMM.shtml