WPAC: CHAN-HOM - Post-Tropical

[euro6208]

000
WTPQ31 PGUM 010901
TCPPQ1

BULLETIN
TROPICAL STORM CHAN-HOM (09W) ADVISORY NUMBER 4
NATIONAL WEATHER SERVICE TIYAN GU WP092015
800 PM CHST WED JUL 1 2015

...CHAN-HOM MAINTAINING INTENSITY NORTHEAST OF CHUUK...

WATCHES AND WARNINGS
--------------------
NONE.

SUMMARY OF 700 PM CHST...0900 UTC...INFORMATION
-----------------------------------------------
LOCATION...10.8N 155.5E

ABOUT 325 MILES NORTHWEST OF POHNPEI
ABOUT 335 MILES NORTHEAST OF CHUUK
ABOUT 720 MILES EAST-SOUTHEAST OF SAIPAN
ABOUT 725 MILES EAST-SOUTHEAST OF TINIAN
ABOUT 730 MILES EAST-SOUTHEAST OF ROTA
ABOUT 750 MILES EAST-SOUTHEAST OF GUAM

MAXIMUM SUSTAINED WINDS...45 MPH
PRESENT MOVEMENT...WEST...275 DEGREES AT 12 MPH

DISCUSSION AND OUTLOOK
----------------------
AT 700 PM CHST...0900 UTC...THE CENTER OF TROPICAL STORM CHAN-HOM
WAS LOCATED NEAR LATITUDE 10.8 DEGREES NORTH AND LONGITUDE 155.5
DEGREES EAST. CHAN-HOM IS MOVING WESTWARD AT 12 MPH. CHAN-HOM IS
EXPECTED TO CONTINUE WESTWARD THROUGH THURSDAY WHILE INCREASING
FORWARD SPEED.

MAXIMUM SUSTAINED WINDS REMAIN AT 45 MPH. TROPICAL STORM WINDS
EXTEND OUTWARD UP TO 60 MILES FROM THE CENTER. TROPICAL STORM CHAN-
HOM IS EXPECTED TO SLOWLY INTENSIFY OVER THE NEXT SEVERAL DAYS.

NEXT ADVISORY
-------------
THE NEXT SCHEDULED ADVISORY WILL BE ISSUED BY THE NATIONAL WEATHER
SERVICE AT 200 AM EARLY THURSDAY MORNING.

$$

WILLIAMS

[euro6208]

At this rate, I wouldn't be surprised if TS and TY warnings will be issued for the Marianas by tomorrow...

We just had our soft opening of Dusit 5 star hotel yesterday which was postpone by Typhoon Dolphin last May. Now another threat is looming.

Activities and festivities are also getting canceled like the 4th of July fireworks, Liberation Carnival (But that runs all month long till next month), and BBQ block party in the heart of Tumon.

Living in typhoon alley, we are accustomed to this although it's disappointing that things like i mentioned above gets affected...

[euro6208]

JMA passes this north of Guam near Saipan weaker as a tropical storm and peaks it at 973 mb east of Taiwan...

NAVGEM brings a strong tropical storm or weak typhoon right over Guam and peaks it also at 973 mb recurving...

CMC hits the Northern Islands!

EURO still aiming for Rota as a strengthening typhoon and a possible Cat 5 for Okinawa

WOW GFS has a midget looking intense typhoon that seems to hit Guam and peaks it at 905 mb and a massive strike for Japan

[euro6208]

TROPICAL STORM CHAN-HOM EAST OF THE MARIANAS IS FORECAST TO MOVE
OVER THE MARIANAS AS EARLY AS SATURDAY MORNING. THIS WILL BRING IN
HEAVY WIND AND RAIN INTO THE AREA BY FRIDAY EVENING. AS CHAN-HOM
CONSOLIDATES FURTHER OVER THE NEXT DAY OR TWO THE TIMING OF EVENTS
WILL BE BETTER UNDERSTOOD. HOWEVER FOR NOW...POSITIONING AND
INTENSITY HAVE BEEN SOMEWHAT UNCERTAIN AS CHAN-HOM IS STILL
INTERACTING WITH THE MONSOON TROUGH TO ITS SOUTH AND WITH ANOTHER
CIRCULATION JUST NORTHWEST OF CHUUK...THIS HAS CREATED A DEGREE OF
UNCERTAINTY IN BOTH THE TIMING OF THE ARRIVAL OF THE STRONG WINDS
AND RAIN AND ALSO THE EXACT PATH. RECENT COMPUTER MODELS HAVE
VARIED SOLUTIONS FROM MOVING THE TC AS A TYPHOON JUST SOUTH OF GUAM
ON SATURDAY MORNING TO RECURVING AS A TROPICAL STORM EAST OF THE
MARIANAS...NEVER ACTUALLY REACHING THE ISLANDS. THE CURRENT FORECAST
FOLLOWS THE LATEST JTWC WARNING FROM WEDNESDAY NOON AND TRACKS CHAN-
NOM ACROSS THE GUAM SOUTHERN COASTAL WATERS...WHILE THE PREVIOUS
JTWC TRACKS WERE CLOSER TO ROTA AREA. IN ANY CASE...THUNDERSTORMS
AND GUSTY WINDS ARE LIKELY TO BEGIN AS EARLY AS FRIDAY AND LAST THE
WEEKEND FOR THE FOUR MAIN ISLANDS.

[euro6208]

Up to 45 knots!

09W CHAN-HOM 150701 1200 11.3N 155.5E WPAC 45 989

[euro6208]

Maybe a start for quicker strengthening?

Latest fix is right in the center of it's massive CDO with convection almost -90C...

[Alyono]

ASCAT is indicating that the center is probably on the eastern edge of the convection

[Alyono]

there is also no evidence of 45 kt winds. Based upon the limited available data, this is 35 kts at best

[Yellow Evan]

there is also no evidence of 45 kt winds. Based upon the limited available data, this is 35 kts at best

ASCAT missed the full storm and found 30 knot winds. That supports 35-40.

JTWC/SAB gave it a 3.0, so that's where there getting 45.

Given that the ASCAt pass was a few hours ago, 40 is good.

[cycloneye]

JMA upgrades to Severe Tropical Storm.

STS 1509 (CHAN-HOM)
Issued at 18:50 UTC, 1 July 2015
<Analyses at 01/18 UTC>
Scale -
Intensity -
Center position N11°25'(11.4°)
E153°50'(153.8°)
Direction and speed of movement W 30km/h(15kt)
Central pressure 985hPa
Maximum wind speed near the center 25m/s(50kt)
Maximum wind gust speed 35m/s(70kt)
Area of 30kt winds or more ALL280km(150NM)

<Forecast for 02/18 UTC>
Intensity Strong
Center position of probability circle N11°25'(11.4°)
E148°00'(148.0°)
Direction and speed of movement W 20km/h(10kt)
Central pressure 970hPa
Maximum wind speed near the center 35m/s(65kt)
Maximum wind gust speed 50m/s(95kt)
Radius of probability circle 130km(70NM)
Storm warning area ALL220km(120NM)

<Forecast for 03/18 UTC>
Intensity Strong
Center position of probability circle N11°55'(11.9°)
E145°55'(145.9°)
Direction and speed of movement W Slowly
Central pressure 965hPa
Maximum wind speed near the center 35m/s(70kt)
Maximum wind gust speed 50m/s(100kt)
Radius of probability circle 200km(110NM)
Storm warning area ALL310km(170NM)

<Forecast for 04/18 UTC>
Intensity Strong
Center position of probability circle N14°10'(14.2°)
E144°30'(144.5°)
Direction and speed of movement NNW 15km/h(7kt)
Central pressure 960hPa
Maximum wind speed near the center 40m/s(75kt)
Maximum wind gust speed 55m/s(105kt)
Radius of probability circle 300km(160NM)
Storm warning area ALL430km(230NM)

<Forecast for 05/18 UTC>
Center position of probability circle N16°40'(16.7°)
E140°20'(140.3°)
Direction and speed of movement WNW 20km/h(12kt)
Radius of probability circle 440km(240NM)

<Forecast for 06/18 UTC>
Center position of probability circle N19°05'(19.1°)
E135°55'(135.9°)
Direction and speed of movement WNW 20km/h(12kt)
Radius of probability circle 560km(300NM)

[euro6208]

The ocean only gets warmer along the track...



EURO has a direct hit 967 mb and bottoms it at 914 mb...




GFS is Rota bound...



891mb for Japan?

[euro6208]

I'd imagine if f 94W wasn't there, this would be a whopper of a typhoon, possibly cat 5 , barreling to the islands. Wherever this goes, it will be significant...

WDPN31 PGTW 012100
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 09W (CHAN-HOM) WARNING
NR 06//
RMKS//
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
TROPICAL STORM (TS) 09W (CHAN-HOM), LOCATED APPROXIMATELY 582 NM
EAST-SOUTHEAST OF ANDERSEN AFB, GUAM HAS TRACKED WESTWARD AT 10
KNOTS OVER THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED SATELLITE
IMAGERY DEPICTS A DEEP CENTRAL DENSE OVERCAST FEATURE OBSCURING THE
LOW LEVEL CIRCULATION CENTER (LLCC). A 011606Z SSMI 85GHZ MICROWAVE
PARTIAL PASS IMAGE SHOWS A WELL DEFINED LLCC WITH TIGHT CURVED
BANDING JUST EAST OF THE DEEPEST CONVECTION. THE INITIAL POSITION IS
BASED ON THE AFOREMENTIONED MICROWAVE IMAGE AND SUPPORTED BY THE
PGTW FIX WITH GOOD CONFIDENCE. THE INITIAL INTENSITY IS HELD AT 45
KNOTS BASED ON CONCURRING DVORAK INTENSITY ESTIMATES FROM ALL
AGENCIES. UPPER LEVEL ANALYSIS INDICATES THAT THE SYSTEM IS LOCATED
IN A MARGINALLY FAVORABLE ENVIRONMENT WITH LOW TO MODERATE (10 TO 20
KNOT) VERTICAL WIND SHEAR (VWS) AND EXCELLENT DIFFLUENT OUTFLOW
ALOFT. TS 09W IS CURRENTLY TRACKING ALONG THE SOUTHERN PERIPHERY OF
A SUB-TROPICAL RIDGE (STR) TO THE NORTH.
3. FORECAST REASONING.
A. NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS
PROGNOSTIC REASONING MESSAGE.
B. TS 09W WILL MAINTAIN A WESTWARD TRAJECTORY THROUGH TAU 36
UNDER THE INFLUENCE OF THE STEERING STR. MARGINALLY FAVORABLE
CONDITIONS WILL PERSIST, ALLOWING GRADUAL INTENSIFICATION. BEYOND
TAU 36, THE STEERING ENVIRONMENT BECOMES MORE COMPLEX AS TS CHAN-HOM
INTERACTS WITH TROPICAL DISTURBANCE (94W) MENTIONED IN THE ABPW10
PGTW 010600. THIS INTERACTION WILL CAUSE TS 09W TO SLOW AND MAINTAIN
CURRENT INTENSITY WITH A POTENTIAL WEAKENING PHASE. CONCURRENTLY,
THE STR WILL BEGIN TO RETREAT TO THE EAST AS A MID-LATITUDE TROUGH
PASSES TO THE NORTH, FORCING TS CHAN-HOM TO TURN NORTHWESTWARD. THE
SYSTEM WILL BEGIN TO INTENSIFY AGAIN DUE TO FAVORABLE SEA SURFACE
TEMPERATURES AND LOW VWS.
C. TS 09W IS EXPECTED TO CONTINUE TRACKING NORTHWESTWARD THROUGH
THE REMAINDER OF THE FORECAST PERIOD TOWARDS A BREAK IN THE STR AND
CONTINUE TO INTENSIFY DUE TO FAVORABLE CONDITIONS. AVAILABLE MODEL
GUIDANCE IS IN EXCELLENT AGREEMENT THROUGH TAU 36; HOWEVER, AS THE
TS 09W INTERACTS WITH 94W, THE TRACK GUIDANCE FANS OUT REACHING
150NM AS THE SYSTEM PASSES THE MARIANA ISLANDS. DUE TO THE
UNCERTAINTY DURING THE INTERACTION PHASE, THERE IS LOW CONFIDENCE IN
THE JTWC FORECAST.//
NNNN

[euro6208]

UW - CIMSS
ADVANCED DVORAK TECHNIQUE
ADT-Version 8.2.1
Tropical Cyclone Intensity Algorithm

----- Current Analysis -----
Date : 01 JUL 2015 Time : 193000 UTC
Lat : 11:09:10 N Lon : 154:29:23 E


CI# /Pressure/ Vmax
3.5 / 994.6mb/ 55.0kt


Final T# Adj T# Raw T#
3.2 3.0 3.0

Center Temp : -50.8C Cloud Region Temp : -59.5C

Scene Type : UNIFORM CDO CLOUD REGION

Positioning Method : FORECAST INTERPOLATION

Ocean Basin : WEST PACIFIC
Dvorak CI > MSLP Conversion Used : PACIFIC

Tno/CI Rules : Constraint Limits : NO LIMIT
Weakening Flag : ON
Rapid Dissipation Flag : FLAG

C/K/Z MSLP Estimate Inputs :
- Average 34 knot radii : 47km
- Environmental MSLP : 1009mb

Satellite Name : MTSAT2
Satellite Viewing Angle : 17.1 degrees

[euro6208]

000
WTPQ31 PGUM 012049
TCPPQ1

BULLETIN
TROPICAL STORM CHAN-HOM (09W) ADVISORY NUMBER 6
NATIONAL WEATHER SERVICE TIYAN GU WP092015
800 AM CHST THU JUL 2 2015

...CHAN-HOM CONTINUING WEST TOWARD THE MARIANAS...

WATCHES AND WARNINGS
--------------------
NONE.

SUMMARY OF 700 AM CHST...2100 UTC...INFORMATION
-----------------------------------------------
LOCATION...11.2N 153.8E

ABOUT 420 MILES NORTHWEST OF POHNPEI
ABOUT 285 MILES NORTH-NORTHEAST OF CHUUK
ABOUT 605 MILES EAST-SOUTHEAST OF SAIPAN
ABOUT 610 MILES EAST-SOUTHEAST OF TINIAN
ABOUT 615 MILES EAST-SOUTHEAST OF ROTA
ABOUT 630 MILES EAST-SOUTHEAST OF GUAM

MAXIMUM SUSTAINED WINDS...50 MPH
PRESENT MOVEMENT...WEST...270 DEGREES AT 12 MPH

DISCUSSION AND OUTLOOK
----------------------
AT 700 AM CHST...2100 UTC...THE CENTER OF TROPICAL STORM CHAN-HOM
WAS LOCATED NEAR LATITUDE 11.2 DEGREES NORTH AND LONGITUDE 153.8
DEGREES EAST. CHAN-HOM IS MOVING WESTWARD AT 12 MPH. CHAN-HOM IS
EXPECTED TO CONTINUE WESTWARD THROUGH FRIDAY WITH A SLIGHT INCREASE
IN FORWARD SPEED BEFORE SLOWING DOWN JUST SOUTHEAST OF THE MARIANAS.

MAXIMUM SUSTAINED WINDS REMAIN AT 50 MPH. TROPICAL STORM WINDS
EXTEND OUTWARD UP TO 60 MILES FROM THE CENTER. TROPICAL STORM
CHAN-HOM IS EXPECTED TO SLOWLY INTENSIFY OVER THE NEXT SEVERAL DAYS.

NEXT ADVISORY
-------------
THE NEXT SCHEDULED ADVISORY WILL BE ISSUED BY THE NATIONAL WEATHER
SERVICE AT 200 PM THIS AFTERNOON.

$$

W. AYDLETT

[Yellow Evan]

01/2032 UTC 11.1N 153.7E T3.0/3.0 CHAN-HOM -- West Pacific

[Alyono]

its not 94W causing this to struggle. It's strong easterly wind shear

[cycloneye]

09W CHAN-HOM 150702 0000 11.2N 152.5E WPAC 55 982

[euro6208]

A TYPHOON WATCH IS NOW IN EFFECT FOR GUAM...ROTA...TINIAN AND
SAIPAN. TYPHOON CONDITIONS...INCLUDING WINDS OF 74 MPH OR MORE...
ARE POSSIBLE WITHIN 48 HOURS.

[Alyono]

rapidscat confirms at least 50 kts

[Yellow Evan]

rapidscat confirms at least 50 kts

I don't disagree with the estimate, just that RapidScat isn't very reliable.