WPAC: CHAMPI - Post-Tropical

[euro6208]

92W INVEST 151012 0600 11.5N 165.5E WPAC 15 1010



Impressive looking system near the dateline.

[euro6208]

NWS

IN ADDITION TO TROPICAL DISTURBANCE 91W...TROPICAL DISTURBANCE 92W
CURRENTLY NEAR 11N165E WILL BE OF CONCERN FOR THE MARIANAS IN THE
COMING DAYS. MODELS DEVELOP 92W OVER THE NEXT SEVERAL DAYS AND
BRING THE SYSTEM TO THE NORTHEAST OF THE FAR NORTHERN MARIANAS BY
THE END OF THE WEEK BEFORE CURVING IT NORTH OVER THE WEEKEND. THIS
COULD CERTAINLY IMPACT THE LONG TERM FORECAST WITH HEAVY RAINFALL
BEING THE MAIN CONCERN.

[1900hurricane]

IR structure is fantastic for an invest. I'm hesitant to go all in without microwave or scatterometer data to support, but 92W might already be worthy of being classified as a tropical depression.

[wxman57]

I agree - looks like it's just about a depression now. JMA may upgrade soon.

[cycloneye]

And it is now a TD.

TD
Issued at 19:30 UTC, 12 October 2015


<Analyses at 12/18 UTC>
Scale -
Intensity -
TD
Center position N11°00'(11.0°)
E162°50'(162.8°)
Direction and speed of movement NW Slowly
Central pressure 1004hPa
Maximum wind speed near the center 15m/s(30kt)
Maximum wind gust speed 23m/s(45kt)

<Forecast for 13/18 UTC>
Intensity -
Center position of probability circle N12°55'(12.9°)
E160°30'(160.5°)
Direction and speed of movement NW 15km/h(7kt)
Central pressure 1000hPa
Maximum wind speed near the center 18m/s(35kt)
Maximum wind gust speed 25m/s(50kt)
Radius of probability circle 220km(120NM)

[euro6208]

LOW

AN AREA OF CONVECTION (INVEST AREA 92W) HAS PERSISTED
NEAR 11.8N 164.4E, APPROXIMATELY 260 NM NORTHWEST OF KWAJALEIN
ATOLL. ANIMATED ENHANCED INFRARED SATELLITE IMAGERY DEPICTS
FRAGMENTED FORMATIVE BANDING BEGINNING TO WRAP INTO A DEVELOPING LOW
LEVEL CIRCULATION CENTER. SCATTEROMETRY INDICATES THIS DISTURBANCE
IS LOCATED WITHIN THE MONSOON TROUGH, WHICH EXTENDS EASTWARD TO THE
MARSHALL ISLANDS. UPPER LEVEL ANALYSIS INDICATES THE DISTURBANCE IS
IN A GENERALLY FAVORABLE ENVIRONMENT WITH LOW (05-10 KNOTS) VERTICAL
WIND SHEAR AND GOOD POLEWARD OUTFLOW. TROPICAL CYCLONE DEVELOPMENT
IS INDICATED IN SOME OF THE GLOBAL MODEL GUIDANCE. MAXIMUM SUSTAINED
SURFACE WINDS ARE ESTIMATED AT 10 TO 15 KNOTS. MINIMUM SEA LEVEL
PRESSURE IS ESTIMATED NEAR 1008 MB. THE POTENTIAL FOR THE
DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE IN THE NEXT 24 HOURS
IS LOW.

[euro6208]

NWS

AS 91W DEPARTS...OUR FOCUS SHIFTS TO 92W...WHICH GFS AND
ECMWF BRING THROUGH THE NORTHERN MARIANAS NORTH OF SAIPAN FRIDAY
OR FRIDAY NIGHT. IT'S TOO EARLY TO SAY EXACTLY HOW 92W WILL
DEVELOP...BUT IT IS GETTING IT'S START FURTHER EAST THAN 91W...AND
MAY HAVE MORE TIME TO DEVELOP AS IT APPROACHES.

NORTH OF KOSRAE NEAR 12N164E WITH DEEP CONVECTION
FOUND MAINLY TO THE WEST AND NORTH OF ITS CENTER. UNSETTLED
CONDITIONS WITH SOUTHWEST TO WEST WINDS WILL PERSIST FOR MOST OF THE
NEXT 5 DAYS FROM CHUUK TO KOSRAE. WINDS WILL BE NORTHWEST AT MAJURO
AS ANOTHER DISTURBANCE APPROACHES IN THE COMING DAYS FROM THE EAST.
MODELS INDICATE WINDS WILL DECREASE AS INVEST 92W MOVES OFF TO THE
WEST-NORTHWEST.

[euro6208]

The disparity continues...

EURO showing only minor development as it crosses the Marianas while GFS is showing a 960 mb typhoon passing north of Saipan. Peaks it at 920 mb...

[1900hurricane]

JTWC upped to medium. With how this is looking right now, I can't help but think a TCFA will be coming soon.

In terms of intensity forecasts, I'd definitely lean aggressive. With how well put together 92W looks right now and if conditions are to be as favorable as I think they will be, it could go up in a hurry. Combined with the developing 91W, I'm liking Goni/Atsani-type intense simultaneous typhoons.

[Yellow Evan]

Looks pretty good to me, but a bit elongated north to south for my liking and most of the convention seems to the off to the left.

Thinking another minimal typhoon here. ECMWF is less bullish with the GFS, but with decent poleward and some equatorward outflow, this should slowly intensify despite moderate wind shear.

[cycloneye]

[euro6208]

WDPN32 PGTW 130900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL DEPRESSION 25W (TWENTYFIVE)
WARNING NR 01//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
TROPICAL DEPRESSION (TD) 25W (TWENTYFIVE), LOCATED APPROXIMATELY
380 NM NORTH-NORTHEAST OF POHNPEI, FSM HAS TRACKED WEST-
NORTHWESTWARD AT 11 KNOTS OVER THE PAST SIX HOURS. RECENT ANIMATED
MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS DEEP FORMATIVE BANDING
ALONG THE WESTERN PERIPHERY OF A CONSOLIDATING LOW LEVEL CIRCULATION
CENTER (LLCC). A 130528Z SSMIS 91GHZ MICROWAVE IMAGE SHOWS BROKEN
CURVED BANDING ALONG THE WESTERN SEMI-CIRCLE WRAPPING INTO THE
CONSOLIDATING LLCC. THE INITIAL POSITION IS PLACED WITH FAIR
CONFIDENCE BASED ON THE MSI LOOP AND THE AFOREMENTIONED MICROWAVE
IMAGE. THE CURRENT INTENSITY IS BASED ON CONCURRING DVORAK INTENSITY
ESTIMATES OF T1.5 (25 KNOTS) FROM ALL AGENCIES AND A RECENT ASCAT
PARTIAL PASS SHOWING 25 KNOT WINDS ALONG THE NORTHERN PERIPHERY.
UPPER LEVEL ANALYSIS INDICATES THE DISTURBANCE IS IN A MARGINALLY-
FAVORABLE ENVIRONMENT WITH 15 TO 20 KNOT EASTERLY VERTICAL WIND
SHEAR (VWS) BEING PARTIALLY OFFSET BY STRONG DIVERGENT OUTFLOW. TD
25W IS TRACKING WESTWARD UNDER THE INFLUENCE OF A SUB-TROPICAL RIDGE
(STR) TO THE NORTH.
3. FORECAST REASONING.
A. THIS IS THE INITIAL PROGNOSTIC REASONING AND SETS THE FORECAST
PHILOSOPHY.
B. TD 25W WILL TRACK ON A WEST-NORTHWESTWARD TRAJECTORY UNDER THE
INFLUENCE OF THE STEERING STR. ENVIRONMENTAL CONDITIONS REMAIN
MOSTLY UNCHANGED LEADING TO A MODEST INTENSIFICATION THROUGH TAU 48.
SEA SURFACE TEMPERATURES WILL INCREASE AND VWS WILL DECREASE
SLIGHTLY AS THE CYCLONE APPROACHES GUAM ALLOWING IT TO CONTINUE
INTENSIFICATION.
C. BEYOND TAU 72, TD 25W WILL CONTINUE TO TRACK GENERALLY WEST-
NORTHWESTWARD. AS THE SYSTEM GAINS LATITUDE, VWS WILL INCREASE ABOVE
15 KNOTS AND SSTS WILL REDUCE, LEADING TO A REDUCED RATE OF
INTENSIFICATION. LIMITED MODEL GUIDANCE IS IN POOR AGREEMENT WITH A
LARGE SPREAD IN BOTH THE NEAR TERM AND THE LONG TERM FORECAST. IN
ADDITION, THERE IS A BIFURCATION AT THE END OF THE FORECAST WITH
SOME MODELS SHOWING A RECURVE SCENARIO WHILE THE OTHER SHOW A
CONTINUED NORTHWESTWARD TRACK. DUE TO THE POOR MODEL AGREEMENT AND
THE UNCERTAINTY IN THE INITIAL POSITION OF THE SYSTEM, THERE IS LOW
CONFIDENCE IN THE JTWC FORECAST.//
NNNN

[euro6208]

000
WTPQ32 PGUM 130916
TCPPQ2

BULLETIN
TROPICAL DEPRESSION (25W) ADVISORY NUMBER 1
NATIONAL WEATHER SERVICE TIYAN GU WP252015
800 PM CHST TUE OCT 13 2015

...TROPICAL DEPRESSION 25W FORMS EAST OF THE MARIANAS...

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

SUMMARY OF 700 PM CHST...0900 UTC...INFORMATION
-----------------------------------------------
LOCATION...12.7N 160.8E

ABOUT 1090 MILES EAST-SOUTHEAST OF AGRIHAN
ABOUT 1065 MILES EAST-SOUTHEAST OF PAGAN
ABOUT 1030 MILES EAST OF SAIPAN
ABOUT 1080 MILES EAST OF GUAM

MAXIMUM SUSTAINED WINDS...30 MPH
PRESENT MOVEMENT...WEST-NORTHWEST...295 DEGREES AT 13 MPH.

DISCUSSION AND OUTLOOK
----------------------
AT 700 PM CHST...0900 UTC...TROPICAL DEPRESSION 25W WAS CENTERED
NEAR LATITUDE 12.7 NORTH AND LONGITUDE 160.8 EAST. THE TROPICAL
DEPRESSION IS MOVING WEST-NORTHWEST AT 13 MPH. IT IS EXPECTED TO
CONTINUE IN THIS GENERAL DIRECTION WITH LITTLE CHANGE IN FORWARD
SPEED OVER THE NEXT FEW DAYS.

MAXIMUM SUSTAINED WINDS ARE 30 MPH. THE TROPICAL DEPRESSION IS
FORECAST TO SLOWLY INTENSIFY AND MAY BECOME A TROPICAL STORM
SOMETIME ON WEDNESDAY.

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

$$

ZIOBRO

[euro6208]

For the past three runs, 18Z, 00Z, and 06Z, GFS likes a Saipan typhoon but trend is weaker only 987 mb now.

[euro6208]

25W TWENTYFIVE 151013 1200 13.0N 159.3E WPAC 25 1004

[1900hurricane]

ASCAT keeps missing the center of 25W, but this last pass did at least pick up a few 30 kt barbs along the edge closest to the center.

[NotoSans]

CI 2.0 from JMA, corresponding to 36 kt on their scale. But they decided to keep it as a TD at 12Z.

[euro6208]

WDPN32 PGTW 131500
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL DEPRESSION 25W (TWENTYFIVE)
WARNING NR 02//
RMKS//
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
TROPICAL DEPRESSION (TD) 25W (TWENTYFIVE), LOCATED APPROXIMATELY
842 NM EAST OF ANDERSEN AFB, GUAM HAS TRACKED WESTWARD AT 16 KNOTS
OVER THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED SATELLITE
IMAGERY DEPICTS A SLIGHT WEAKENING AND DISORGANIZATION IN THE
CONVECTION ASSOCIATED WITH THE LOW LEVEL CIRCULATION CENTER (LLCC).
A 131311Z GPM 36GHZ MICROWAVE IMAGE SHOWED A BETTER DEFINED LLCC AND
CURVED CONVECTIVE BANDING LOCATED ALONG THE WESTERN PERIPHERY. THE
CURRENT POSITION IS BASED ON THE LLCC IN THE MICROWAVE IMAGE AND
SUPPORTED BY AGENCY SATELLITE FIXES FROM PGTW AND RJTD WITH FAIR
CONFIDENCE. THE INTENSITY HAS BEEN HELD AT 25 KNOTS BASED ON AN
ASSESSMENT OF DVORAK INTENSITY ESTIMATES AND SUPPORTED BY THE MOSTLY
UNCHANGED CONVECTIVE STRUCTURE. UPPER LEVEL ANALYSIS INDICATES THAT
THE SYSTEM IS IN A MARGINALLY-FAVORABLE ENVIRONMENT WITH 15 TO 20
KNOT EASTERLY VERTICAL WIND SHEAR (VWS) BEING PARTIALLY OFFSET BY
STRONG DIVERGENT OUTFLOW. TD 25W IS TRACKING WESTWARD UNDER THE
INFLUENCE OF A SUB-TROPICAL RIDGE (STR) TO THE NORTH.
3. FORECAST REASONING.
A. NO CHANGE TO FORECAST PHILOSOPHY SINCE THE PREVIOUS PROGNOSTIC
REASONING MESSAGE.
B. TD 25W WILL TRACK WEST-NORTHWESTWARD UNDER THE INFLUENCE OF
THE STEERING STR THROUGHOUT THE FORECAST PERIOD. ENVIRONMENTAL
CONDITIONS WILL REMAIN MARGINALLY-FAVORABLE LEADING TO A SLIGHT
INTENSIFICATION THROUGH TAU 48. SEA SURFACE TEMPERATURES WILL
INCREASE AND VWS WILL SLIGHTLY DECREASE AS THE CYCLONE APPROACHES
GUAM ALLOWING THE INTENSIFICATION RATE TO INCREASE.
C. BEYOND TAU 72, TD 25W WILL CONTINUE TO TRACK ON A WEST-
NORTHWESTWARD TRAJECTORY. AS THE SYSTEM GAINS LATITUDE, VWS WILL
INCREASE ABOVE 15 KNOTS AND SSTS WILL DECREASE, LEADING TO A REDUCED
RATE OF INTENSIFICATION. LIMITED MODEL GUIDANCE IS IN POOR AGREEMENT
WITH A LARGE SPREAD IN BOTH THE NEAR TERM AND THE LONG TERM
FORECAST. IN ADDITION, THERE IS A BIFURCATION AT THE END OF THE
FORECAST WITH SOME MODELS SHOWING A RECURVE SCENARIO WHILE THE
OTHERS SHOW A CONTINUED NORTHWESTWARD TRACK. DUE TO THE POOR MODEL
AGREEMENT AND THE UNCERTAINTY IN THE INITIAL POSITION OF THE SYSTEM,
THERE IS LOW CONFIDENCE IN THE JTWC FORECAST.//
NNNN

[1900hurricane]

I'm frankly a little surprised models aren't more bullish with 25W right now. Taking a look at them, it looks like they have easterly shear keeping it in check, but I'm not so sure that's what is going to result. With a very deep tropopause (evidenced by sounding data and cloudtops consistently between -80 and -90*C) and the second most heat laden waters in the entire WPac ahead of it (only after the waters Koppu will be traversing), it wouldn't surprise me to see outflow from the vigorous convection keep shear in check. 25W certainly won't have dry air to contend with since it's shrouded in about as deep a PW field as you can get. I realize I'm somewhat going against guidance, but I'm still feeling bullish with intensity. The setup just looks ripe to me.

[euro6208]

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

----- Current Analysis -----
Date : 13 OCT 2015 Time : 143000 UTC
Lat : 13:04:58 N Lon : 158:52:24 E


CI# /Pressure/ Vmax
1.9 /1008.9mb/ 29.0kt


Final T# Adj T# Raw T#
1.7 2.2 2.2

Center Temp : -35.6C Cloud Region Temp : -36.2C

Scene Type : CURVED BAND with 0.42 ARC in LT GRAY
Maximum CURVED BAND with 0.48 ARC in LT GRAY
at Lat: 13:28:47 N Lon: 159:04:12 E

Positioning Method : FORECAST INTERPOLATION

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

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

C/K/Z MSLP Estimate Inputs :
- Average 34 knot radii : N/A
- Environmental MSLP : 1011mb

Satellite Name : MTSAT2
Satellite Viewing Angle : 22.2 degrees