WPAC: NOUL - Post-Tropical

[euro6208]

WTPN21 PGTW 020830
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE FORMATION ALERT//
RMKS/
1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN
100 NM EITHER SIDE OF A LINE FROM 7.4N 144.2E TO 8.4N 140.6E
WITHIN THE NEXT 12 TO 24 HOURS. AVAILABLE DATA DOES NOT JUSTIFY
ISSUANCE OF NUMBERED TROPICAL CYCLONE WARNINGS AT THIS TIME.
WINDS IN THE AREA ARE ESTIMATED TO BE 15 TO 20 KNOTS. METSAT
IMAGERY AT 020600Z INDICATES THAT A CIRCULATION CENTER IS LOCATED
NEAR 7.4N 144.0E. THE SYSTEM IS MOVING WESTWARD AT 10 KNOTS.
2. REMARKS: THE AREA OF CONVECTION PREVIOUSLY LOCATED NEAR 6.7N
145.5E, IS NOW LOCATED NEAR 7.4N 144.1E, APPROXIMATELY 360 NM SOUTH
OF GUAM. RECENT ANIMATED MULTISPECTRAL SATELLITE IMAGERY SHOWS DEEP
CONVECTION DEVELOPING ALONG THE WESTERN PERIPHERY OF A LOW LEVEL
CIRCULATION CENTER (LLCC) ALSO EVIDENT IN RECENT MICROWAVE SATELLITE
IMAGERY INCLUDING A 020414Z AMSU PASS. THIS DISTURBANCE LIES
EQUATORWARD OF AN UPPER-LEVEL RIDGE AXIS, IN AN AREA OF LOW TO
MODERATE EASTERLY VERTICAL WIND SHEAR, INCREASING OUTFLOW ALOFT,
AND FAVORABLE SEA SURFACE TEMPERATURES. DYNAMIC MODEL GUIDANCE
INDICATES TROPICAL CYCLONE FORMATION WITHIN THE NEXT DAY OR TWO.
MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 15 TO 20 KNOTS.
MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1007 MB. BASED
ON LOW-LEVEL CONSOLIDATION, IMPROVING CONVECTIVE SIGNATURE, AND
FAVORABLE ENVIRONMENTAL SUPPORT, THE POTENTIAL FOR THE DEVELOPMENT
OF A SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24 HOURS IS HIGH.
3. THIS ALERT WILL BE REISSUED, UPGRADED TO WARNING OR CANCELLED BY
030830Z.//
NNNN

[euro6208]

TPPN10 PGTW 020601

A. TROPICAL DISTURBANCE 92W (SE OF GUAM)

B. 02/0532Z

C. 7.49N

D. 143.65E

E. FIVE/MTSAT

F. T1.0/1.0

G. IR/EIR/VIS/MSI

H. REMARKS: 40A/PBO SBC/ANMTN. CNVCTN WRAPS .30 ON LOG10 SPIRAL
YIELDING A DT OF 1.0. MET AND PT ARE UNAVAILABLE. DBO DT.

I. ADDITIONAL POSITIONS: NONE


LEMBKE

[euro6208]

TXPQ28 KNES 020914
TCSWNP

A. TROPICAL DISTURBANCE (92W)

B. 02/0832Z

C. 7.3N

D. 143.4E

E. THREE/MTSAT

F. T1.5/1.5/D1.5/24HRS

G. IR/EIR/SWIR

H. REMARKS...CONVECTION BAND WRAPS 3/10 FOR A DT OF 1.5. MET IS 1.0
AND PT IS 1.5. FT IS BASED ON DT.

I. ADDL POSITIONS

NIL


...VELASCO

[cycloneye]

JMA upgrades to minor TD.

TROPICAL DEPRESSION 1006 HPA AT 07N 145E WEST 10 KT

[euro6208]

000
WWPQ80 PGUM 021050 CCA
SPSPQ

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE TIYAN GU
850 PM CHST SAT MAY 2 2015

PMZ171-030600-
YAP-
850 PM CHST SAT MAY 2 2015

...TROPICAL DISTURBANCE IN YAP STATE LIKELY TO DEVELOP...

THE TROPICAL DISTURBANCE IN YAP STATE HAS GOOD POTENTIAL TO DEVELOP
AND IS NOW THE SUBJECT OF A TROPICAL CYCLONE FORMATION ALERT ISSUED
BY THE JOINT TYPHOON WARNING CENTER. AT 630 PM CHST...THE CENTER OF
THE DISTURBANCE WAS LOCATED BY SATELLITE NEAR 7.5 DEGREES NORTH AND
143.2 DEGREES EAST. THIS IS ABOUT 120 MILES SOUTHWEST OF FARAULEP...
50 MILES WEST OF WOLEAI AND 375 MILES EAST-SOUTHEAST OF YAP. IT IS
MOVING WEST AT ABOUT 12 MPH.

THE FUTURE DEVELOPMENT AND TRACK OF THIS DISTURBANCE IS STILL
UNCERTAIN...BUT THERE IS A GOOD CHANCE IT WILL MOVE TOWARD THE WEST-
NORTHWEST IN THE GENERAL DIRECTION OF YAP...ULITHI AND FAIS OVER THE
NEXT TWO OR THREE DAYS AS IT DEVELOPS.

RESIDENTS OF WESTERN YAP STATE...ESPECIALLY ON YAP...ULITHI AND
FAIS...SHOULD KEEP ADVISED ON THE DEVELOPMENT OF THIS DISTURBANCE.
LISTEN FOR ANY FURTHER STATEMENTS OR ADVISORIES FROM THE NATIONAL
WEATHER SERVICE AND YOUR LOCAL WEATHER OFFICE.

$$

MIDDLEBROOKE

[euro6208]

06Z Double wammy for Yap and Luzon...

[cycloneye]

JMA upgrades to bonifide TD.

TD
Issued at 13:20 UTC, 2 May 2015
<Analyses at 02/12 UTC>
Scale -
Intensity -
TD
Center position N7°25'(7.4°)
E142°35'(142.6°)
Direction and speed of movement W 20km/h(10kt)
Central pressure 1006hPa
Maximum wind speed near the center 15m/s(30kt)
Maximum wind gust speed 23m/s(45kt)

<Forecast for 03/12 UTC>
Intensity -
Center position of probability circle N8°30'(8.5°)
E139°25'(139.4°)
Direction and speed of movement WNW 15km/h(8kt)
Central pressure 1002hPa
Maximum wind speed near the center 18m/s(35kt)
Maximum wind gust speed 25m/s(50kt)
Radius of probability circle 220km(120NM)

[euro6208]

Still no upgrade...

92W INVEST 150502 1800 7.9N 141.9E WPAC 20 1007

[euro6208]

JMA tropical storm into Luzon



NAVGEM typhoon for Western Micronesia



CMC takes this to Yap and maybe Luzon




EURO is very conservative only sensing a TD/TS

[cycloneye]

TPPN10 PGTW 022127

A. TROPICAL DISTURBANCE 92W (SE OF PALAU)

B. 02/2032Z

C. 7.78N

D. 141.66E

E. FIVE/MTSAT

F. T2.0/2.0 STT: D0.5/03HRS

G. IR/EIR

H. REMARKS: 38A/PBO SBC/ANMTN. CNVCTN WRAPS .35 ON LOG10 SPIRAL
YIELDING A DT OF 2.0. MET & PT NOT AVAILABLE. DBO DT.

I. ADDITIONAL POSITIONS: NONE


BERMEA

[euro6208]

KNES also coming in at 2.0...

I expect an upgrade in 00Z...

TXPQ28 KNES 022130
TCSWNP

A. TROPICAL DISTURBANCE (92W)

B. 02/2032Z

C. 7.6N

D. 142.3E

E. THREE/MTSAT

F. T2.0/2.0/D1.0/18HRS

G. IR/EIR/SWIR

H. REMARKS...DT OF 2.5 IS BASED ON 0.4 BANDING. MET IS 1.5 AND PT IS
2.0. FT IS BASED ON PT.

I. ADDL POSITIONS

NIL


...RAMIREZ

[euro6208]

OTHER THAN THE MONSOON TROUGH THAT STRETCHES ACROSS WESTERN
MICRONESIA...THE DOMINANT WEATHER FEATURE REMAINS JTWC INVEST AREA
92W...CENTERED SOUTHEAST OF YAP NEAR 7N142E. THIS CIRCULATION
REMAINS THE SUBJECT OF A TROPICAL CYCLONE FORMATION ALERT. ONLY
MINOR CHANGES WERE MADE IN THE SHORT TERM FORECASTS AT THE 3
LOCALES...HOWEVER THE FORECASTS FOR YAP AND KOROR WERE MODIFIED TO
SHOW THE PASSAGE OF A CIRCULATION PASSING NEAR AND JUST NORTH OF
YAP AROUND MIDWEEK. THE QUESTION IS NO LONGER IF SOMETHING WILL
DEVELOP FROM 92W...BUT WHEN AND HOW MUCH. MODELS STILL SUGGEST A
TROPICAL DEPRESSION-STRENGTH SYSTEM PASSING NEAR YAP SOMETIME
TUESDAY THRU THURSDAY. WILL MAINTAIN A MORE CONSERVATIVE BIAS IN
THE FORECAST IN THE LONG-TERM FOR NOW.

[euro6208]

18Z deepens Noul into a typhoon in just 42 hours and strikes Yap...

[euro6208]

06W is here...

06W SIX 150502 1800 7.9N 141.9E WPAC 20 1007

[cycloneye]

First JTWC warning. Peak is 80kts at the end.

[euro6208]

000
WTPQ31 PGUM 030202
TCPPQ1

BULLETIN
TROPICAL DEPRESSION 06W ADVISORY NUMBER 1
NATIONAL WEATHER SERVICE TIYAN GU WP062015
1200 PM CHST SUN MAY 3 2015

...TROPICAL DEPRESSION 06W FORMS OVER YAP STATE...

WATCHES AND WARNINGS
--------------------
A TROPICAL STORM WATCH IS NOW IN EFFECT FOR YAP ISLAND AND NGULU IN YAP STATE.

SUMMARY OF 100 PM CHST...0300 UTC...INFORMATION
-----------------------------------------------
LOCATION...8.1N 140.9E

ABOUT 155 MILES SOUTHEAST OF ULITHI
ABOUT 211 MILES WES-NORTHWEST OF WOLEAI
ABOUT 215 MILES EAST-SOUTHEAST OF YAP
ABOUT 235 MILES EAST OF NGULU
ABOUT 425 MILES EAST OF KAYANGEL
ABOUT 450 MILES EAST OF KOROR AND
ABOUT 450 MILES SOUTHWEST OF GUAM

MAXIMUM SUSTAINED WINDS...30 MPH
PRESENT MOVEMENT...WEST...280 DEGREES AT 8 MPH

DISCUSSION AND OUTLOOK
----------------------
AT 100 PM CHST...0300 UTC...THE CENTER OF TROPICAL DEPRESSION 6W IS
EXPECTED TO BE NEAR LATITUDE 8.1 NORTH AND LONGITUDE 140.9
EAST...MOVING WEST AT 8 MPH. A GENERAL WEST-NORTHWEST MOTION IS
EXPECTED FOR THE NEXT SEVERAL DAYS...TAKING THE TROPICAL DEPRESSION
NEAR YAP MONDAY NIGHT AS A TROPICAL STORM.

MAXIMUM SUSTAINED WINDS ARE AT 30 MPH. TROPICAL DEPRESSION 06W IS
EXPECTED TO CONTINUE TO INTENSIFY DURING THE NEXT FEW DAYS...AND MAY
BECOME A TROPICAL STORM LATER TONIGHT.

NEXT ADVISORY
-------------
AN INTERMEDIATE ADVISORY WILL BE ISSUED BY THE NATIONAL WEATHER
SERVICE AT 500 PM...FOLLOWED BY THE NEXT SCHEDULED ADVISORY AT 800
PM THIS EVENING.

$$

ZIOBRO

[euro6208]

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

----- Current Analysis -----
Date : 03 MAY 2015 Time : 013000 UTC
Lat : 8:02:44 N Lon : 141:03:04 E


CI# /Pressure/ Vmax
1.6 /1009.0mb/ 26.0kt


Final T# Adj T# Raw T#
1.6 1.7 2.3

Center Temp : -12.7C Cloud Region Temp : -30.5C

Scene Type : CURVED BAND with 0.29 ARC in DK GRAY
Maximum CURVED BAND with 0.60 ARC in DK GRAY
at Lat: 8:02:23 N Lon: 140:03:00 E

Positioning Method : FORECAST INTERPOLATION

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

Tno/CI Rules : Constraint Limits : 0.2T/hour
Weakening Flag : OFF
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 : 10.5 degrees

[euro6208]

WDPN31 PGTW 030300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL DEPRESSION 06W WARNING NR 1//
RMKS//
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
TROPICAL DEPRESSION 06W (SIX), LOCATED APPROXIMATELY 205 NM EAST-
SOUTHEAST OF YAP, HAS TRACKED WESTWARD AT 07 KNOTS OVER THE PAST
SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) SHOWS THE
SYSTEM HAS CONSOLIDATED AS CONVECTIVE BANDS, ALBEIT FRAGMENTED AND
SHALLOW, WRAPPED TIGHTER INTO A BROAD AND ILL-DEFINED LOW LEVEL
CIRCULATION CENTER. THE INITIAL POSITION IS BASED ON THE MSI LOOP
AND EXTRAPOLATED FROM A LOW REFLECTIVITY NOTCH FEATURE ON A 022222Z
SSMIS MICROWAVE PASS WITH FAIR CONFIDENCE. THE INITIAL INTENSITY OF
25 KNOTS IS BASED ON AN OVERALL ASSESSMENT OF DVORAK ESTIMATES FROM
PGTW, KNES, AND RJTD. UPPER LEVEL ANALYSIS INDICATES TD 06W IS JUST
SOUTH OF THE RIDGE AXIS IN AN AREA OF MODERATE (15-20 KNOT) EASTERLY
VERTICAL WIND SHEAR (VWS). HOWEVER, THE VWS IS SUBSTANTIALLY OFFSET
BY GOOD RADIAL OUTFLOW, WITH A STRONG POLEWARD BIAS. THE CYCLONE IS
CURRENTLY TRACKING ALONG THE SOUTHERN PERIPHERY OF AN EXTENSION OF
THE SUBTROPICAL RIDGE (STR) TO THE NORTHEAST.
3. FORECAST REASONING.
A. THIS IS THE INITIAL PROGNOSTIC REASONING BULLETIN AND SETS THE
FORECAST PHILOSOPHY FOR THIS SYSTEM.
B. TD 06W IS EXPECTED TO SLOW DOWN OVER THE NEXT 36 HOURS AS IT
APPROACHES A BREAK BETWEEN THE AFOREMENTIONED STR LEAF AND A NEW STR
LEAF TO THE NORTHWEST. AFTERWARDS, THE NEW STR LEAF WILL ASSUME
STEERING AND DRIVE THE CYCLONE ON A WEST-NORTHWESTWARD (WNW)
TRAJECTORY TOWARDS LUZON, PHILIPPINES. THE VWS IS EXPECTED TO WEAKEN
AND OUTFLOW TO REMAIN ROBUST. THESE, PLUS THE PERENNIAL WARM WATERS
OF THE PHILIPPINE SEA WILL FUEL STEADY INTENSIFICATION.
C. IN THE EXTENDED TAUS, TD 06W WILL CONTINUE TO INTENSIFY AND
REMAIN ON A WNW TRACK UNDER THE STEERING INFLUENCE OF THE NEW STR
LEAF. BY END OF FORECAST, THE SYSTEM WILL BE AT TYPHOON INTENSITY OF
8O KNOTS, POSSIBLY STRONGER. THE INITIAL SET OF NUMERIC GUIDANCE IN
LOOSE AGREEMENT AND GIVEN THE UNCERTAIN STORM MOTION AS THE CYCLONE
APPROACHES A WEAK STEERING ENVIRONMENT, THERE IS LOW CONFIDENCE IN
THE FIRST JTWC FORECAST TRACK ON THIS SYSTEM.//
NNNN

[euro6208]

000
WTPQ81 PGUM 030512
HLSPQ1

URGENT - IMMEDIATE BROADCAST REQUESTED
TROPICAL DEPRESSION 06W LOCAL STATEMENT
NATIONAL WEATHER SERVICE TIYAN GU
300 PM CHST SUN MAY 3 2015

...TROPICAL DEPRESSION 06W FORMS EAST-SOUTHEAST OF YAP...

.AREAS AFFECTED...
THIS LOCAL STATEMENT PROVIDES INFORMATION AND RECOMMENDED ACTIONS
FOR PEOPLE ON YAP AND NGULU ISLANDS OF YAP STATE.

.WATCHES/WARNINGS...
A TROPICAL STORM WATCH IS NOW IN EFFECT FOR YAP ISLAND AND NGULU IN
YAP STATE.

SUMMARY OF 100 PM CHST...0300 UTC...INFORMATION
-----------------------------------------------
LOCATION...8.1N 140.9E

ABOUT 155 MILES SOUTHEAST OF ULITHI
ABOUT 211 MILES WEST-NORTHWEST OF WOLEAI
ABOUT 215 MILES EAST-SOUTHEAST OF YAP
ABOUT 235 MILES EAST OF NGULU
ABOUT 425 MILES EAST OF KAYANGEL
ABOUT 450 MILES EAST OF KOROR AND
ABOUT 450 MILES SOUTHWEST OF GUAM

MAXIMUM SUSTAINED WINDS...30 MPH
PRESENT MOVEMENT...WEST...280 DEGREES AT 8 MPH

.SITUATION OVERVIEW...
TROPICAL DEPRESSION 06W IS CURRENTLY MOVING WESTWARD BUT IS EXPECTED
TO TURN TOWARD THE WEST-NORTHWEST THIS EVENING. THE CURRENT TRACK HAS
TD 06W PASSING BETWEEN NGULU AND YAP ISLAND MONDAY NIGHT INTO TUESDAY
MORNING. SLOW INTENSIFICATION IS EXPECTED OVER THE NEXT FEW DAYS WITH
06W POSSIBLY BECOMING A TROPICAL STORM TONIGHT.

...YAP...

...PRECAUTIONARY/PREPAREDNESS ACTIONS...
PREPARATIONS FOR DAMAGING TROPICAL STORM FORCE WINDS OF 35 MPH OR
MORE SHOULD BE COMPLETED BY MONDAY AFTERNOON. TROPICAL STORM
CONDITIONS ARE EXPECTED MONDAY NIGHT AND TUESDAY MORNING. MAKE
SURE YOU HAVE ADEQUATE FOOD AND WATER FOR THE NEXT SEVERAL DAYS.
LISTEN FOR UPDATED INFORMATION. IF NECESSARY...BE PREPARED TO GO
TO A SHELTER. DO NOT ATTEMPT INTER-ISLAND TRAVEL OVER THE NEXT FEW
DAYS.

...WIND INFORMATION...
NORTHEAST WINDS OF 10 TO 20 MPH TONIGHT WILL INCREASE TO 15 TO 30
MPH MONDAY. WINDS WILL SHIFT TO EAST MONDAY NIGHT AND INCREASE TO
NEAR TROPICAL STORM FORCE OF 40 MPH. AS 06W PASSES BY TO THE SOUTH
EARLY TUESDAY MORNING...WINDS WILL SHIFT TO THE SOUTH AND GRADUALLY
DIMINISH THROUGH THE DAY AND TUESDAY NIGHT.

...STORM SURGE AND SURF INFORMATION...
COMBINED SEAS OF 4 TO 6 FT TONIGHT WILL BUILD TO BETWEEN 6 TO 9 FT
MONDAY. SEAS ARE EXPECTED TO PEAK AT BETWEEN 9 AND 13 FT MONDAY
NIGHT AND TUESDAY BEFORE GRADUALLY SUBSIDING BEGINNING TUESDAY
NIGHT. SURF OF 5 TO 7 FT ALONG EAST FACING REEFS WILL STEADILY
INCREASE MONDAY TO BETWEEN 8 AND 11 FT. SURF WILL REACH HAZARDOUS
LEVELS OF 12 FT ALONG EAST FACING REEFS MONDAY EVENING. SURF IS
EXPECTED TO PEAK BETWEEN 11 AND 14 FT MONDAY NIGHT AND TUESDAY.
SURF ALONG SOUTH FACING REEFS IS EXPECTED TO REACH HAZARDOUS LEVELS
OF 9 FT MONDAY NIGHT AND PEAK AT BETWEEN 11 AND 14 FT TUESDAY.
MINOR COASTAL INUNDATION IS POSSIBLE...ESPECIALLY DURING TIMES OF
HIGH TIDE.

...OTHER STORM EFFECTS...
RAINFALL OF 4 TO 6 INCHES IS EXPECTED BEGINNING MONDAY AND LASTING
THROUGH TUESDAY AFTERNOON.

...NGULU...

...PRECAUTIONARY/PREPAREDNESS ACTIONS...
PREPARATIONS FOR DAMAGING TROPICAL STORM FORCE WINDS OF 35 MPH OR
MORE SHOULD BE COMPLETED BY MONDAY AFTERNOON. TROPICAL STORM
CONDITIONS ARE POSSIBLE MONDAY NIGHT AND TUESDAY MORNING. MAKE
SURE YOU HAVE ADEQUATE FOOD AND WATER FOR THE NEXT SEVERAL DAYS.
LISTEN FOR UPDATED INFORMATION. IF NECESSARY...BE PREPARED TO GO
TO A SHELTER. DO NOT ATTEMPT INTER-ISLAND TRAVEL OVER THE NEXT FEW
DAYS.

...WIND INFORMATION...
NORTHEAST WINDS OF 10 TO 15 MPH TONIGHT WILL INCREASE TO 15 TO 25
MPH MONDAY. WINDS WILL SHIFT TO THE NORTHWEST MONDAY AND INCREASE TO
NEAR TROPICAL STORM FORCE OF 40 MPH. AS 06W PASSES BY TO THE NORTH
EARLY TUESDAY MORNING...WINDS WILL SHIFT TO THE WEST AND GRADUALLY
DIMINISH THROUGH THE DAY AND TUESDAY NIGHT.

...STORM SURGE AND SURF INFORMATION...
COMBINED SEAS OF 4 TO 6 FT TONIGHT WILL BUILD TO BETWEEN 6 TO 9 FT
MONDAY. SEAS ARE EXPECTED TO PEAK AT BETWEEN 9 AND 13 FT MONDAY
NIGHT AND TUESDAY BEFORE GRADUALLY SUBSIDING BEGINNING TUESDAY
NIGHT. SURF OF 5 TO 7 FT ALONG NORTH AND EAST FACING REEFS WILL
STEADILY INCREASE TO HAZARDOUS LEVELS OF 8 TO 12 FT MONDAY. SURF IS
EXPECTED TO PEAK BETWEEN 11 AND 14 FT MONDAY NIGHT AND TUESDAY.
MINOR COASTAL INUNDATION IS POSSIBLE...ESPECIALLY DURING TIMES OF
HIGH TIDE.

...OTHER STORM EFFECTS...
RAINFALL OF 3 TO 5 INCHES IS EXPECTED BEGINNING MONDAY AND LASTING
THROUGH TUESDAY AFTERNOON.

&&

.NEXT UPDATE...
THE NEXT LOCAL STATEMENT WILL BE ISSUED BY THE NATIONAL WEATHER
SERVICE THIS EVENING AT 900 PM.

$$

W. AYDLETT

[euro6208]

Peak intensity increased significantly up to 110 knots, category 3...

Yap is in for a pounding...

WDPN31 PGTW 030900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL DEPRESSION 06W WARNING NR 02//
RMKS//
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
TROPICAL DEPRESSION (TD) 06W (SIX), LOCATED APPROXIMATELY 212 NM
EAST-SOUTHEAST OF YAP, HAS TRACKED NORTHWESTWARD AT 05 KNOTS OVER THE
PAST SIX HOURS. THE PREVIOUS POSITION HAS BEEN ADJUSTED EASTWARD
SLIGHTLY BASED ON NEWLY-AVAILABLE SATELLITE DATA. THE CURRENT
POSITION IS BASED ON A RECENT PGTW SATELLITE POSITION FIX AND
ANIMATED MULTISPECTRAL SATELLITE IMAGERY. THE CURRENT INTENSITY OF
25 KNOTS IS CONSISTENT WITH DVORAK SATELLITE INTENSITY ESTIMATES
FROM MULTIPLE REPORTING AGENCIES. FRAGMENTED DEEP CONVECTION IS
CONFINED PRIMARILY TO THE NORTHERN PORTION OF THE PARTIALLY-EXPOSED
LOW-LEVEL CIRCULATION CENTER (LLCC). THE LLCC LIES EQUATORWARD OF AN
UPPER-LEVEL RIDGE AXIS, IN AN AREA OF LOW TO MODERATE EASTERLY
VERTICAL WIND SHEAR AND FAVORABLE POLEWARD OUTFLOW. STORM MOTION HAS
DECREASED IN THE PAST 12 HOURS IN RESPONSE TO A DEVELOPING WEAKNESS
IN THE SUBTROPICAL STEERING RIDGE TO THE NORTH OF THE SYSTEM.
3. FORECAST REASONING.
A. FORECAST TRACK SPEEDS HAVE DECREASED SINCE THE PREVIOUS
WARNING IN ANTICIPATION OF A WEAKENED STEERING ENVIRONMENT DURING
NEXT 48 TO 72 HOURS. MEDIUM TO EXTENDED RANGE FORECAST INTENSITIES
HAVE INCREASED BASED ON FAVORABLE UPPER-LEVEL SUPPORT.
B. TD 06W IS EXPECTED TO TRACK SLOWLY WEST-NORTHWESTWARD OVER THE
NEXT 48 TO 72 HOURS AS IT ENCOUNTERS A WEAKNESS IN THE SUBTROPICAL
RIDGE. THEREAFTER, A MID-LATITUDE TROUGH INDUCING THE WEAKNESS WILL
MOVE EASTWARD, ALLOWING THE SUBTROPICAL RIDGE TO REBUILD AND STEER
THE SYSTEM MORE RAPIDLY INTO THE PHILIPPINE SEA. VERTICAL WIND SHEAR
SHOULD REMAIN LOW AND UPPER-LEVEL OUTFLOW IS EXPECTED TO IMPROVE,
ENABLING TD 06W TO STEADILY INTENSIFY AFTER AN INITIAL PERIOD OF
CONSOLIDATION DURING THE NEXT 12 HOURS. NUMERIC MODELS ARE GENERALLY
IN GOOD AGREEMENT REGARDING TRACK DIRECTION BUT LESS AGREEMENT
REGARDING TRACK SPEED DURING THE FIRST 72 HOURS OF THE FORECAST.
GIVEN HIGH UNCERTAINTY ASSOCIATED WITH THE DEVELOPING WEAKNESS IN
THE STEERING RIDGE, THE LOW-CONFIDENCE JTWC FORECAST IS PLACED NEAR
THE MULTI-MODEL CONSENSUS.
C. IN THE EXTENDED TAUS, TD 06W WILL TRACK STEADILY WEST-
NORTHWESTWARD UNDER THE STEERING INFLUENCE OF THE REORIENTED
SUBTROPICAL RIDGE. THE SYSTEM SHOULD CONTINUE TO INTENSIFY AS
ENVIRONMENTAL INFLUENCES REMAIN FAVORABLE. NUMERIC MODEL GUIDANCE IS
IN BETTER AGREEMENT REGARDING TRACK DIRECTION AND SPEED IN THE
EXTENDED TERM, LENDING HIGHER CONFIDENCE TO THE JTWC 96 AND 120 HOUR
FORECAST POSITIONS.//
NNNN