WPAC: NESAT - Post-Tropical

[euro6208]

WDPN34 PGTW 260300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL DEPRESSION 11W (ELEVEN)
WARNING NR 01//
RMKS//
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
TROPICAL DEPRESSION (TD) 11W (ELEVEN), LOCATED APPROXIMATELY 440
NM EAST OF MANILA, PHILIPPINES, HAS TRACKED NORTH-NORTHEASTWARD AT
07 KNOTS OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE
IMAGERY DEPICTS A CONSOLIDATING, PARTIALLY-EXPOSED LOW-LEVEL
CIRCULATION CENTER (LLCC) WITH IMPROVED CONVECTIVE BANDING WRAPPING
INTO THE SOUTH QUADRANT OF THE LLCC. A 260132Z METOP-B 89GHZ IMAGE
SHOWS CURVED DEEP CONVECTIVE BANDING OVER THE SOUTHERN SEMI-CIRCLE
WITH DEFINED SHALLOW BANDING ELSEWHERE WRAPPING INTO THE CENTER.
ENVIRONMENTAL ANALYSIS REVEALS EXCELLENT EQUATORWARD OUTFLOW, GOOD
POLEWARD OUTFLOW ENHANCED BY A TUTT TO THE NORTH, WARM SST 30-31C,
AND HIGH OCEAN HEAT CONTENT VALUES. OVERALL, THERE IS FAIR
CONFIDENCE IN THE INITIAL POSITION BASED ON THE BROAD NATURE OF THE
CENTER. THE INITIAL INTENSITY IS ASSESSED AT 30 KNOTS BASED ON
DVORAK INTENSITY ESTIMATES RANGING FROM T1.5 TO T2.0 (25 TO 30
KNOTS) AND RECENT ASCAT DATA SHOWING NUMEROUS 30 KNOT WINDS OVER THE
SOUTHERN SEMI-CIRCLE OF THE SYSTEM. TD 11W IS TRACKING SLOWLY
NORTHWARD ALONG THE WESTERN PERIPHERY OF A NORTH-SOUTH ORIENTED
STEERING RIDGE.
3. FORECAST REASONING.
A. THIS IS THE FIRST PROGNOSTIC REASONING MESSAGE AND SETS THE
FORECAST PHILOSOPHY.
B. TD 11W IS FORECAST TO TRACK NORTHWARD ALONG THE WESTERN
PERIPHERY OF THE STEERING RIDGE THROUGH TAU 48 BUT SHOULD TURN NORTH-
NORTHWESTWARD AND SLOW SLIGHTLY AS IT TRANSITIONS TO THE SUBTROPICAL
RIDGE TO THE NORTH. DYNAMIC GUIDANCE IS IN POOR AGREEMENT WITH A
BIFURCATION IN SOLUTIONS. GENERALLY, NAVGEM, ECMWF AND UKMO DEPICT A
WEAKER SYSTEM WHICH GETS PULLED INTO THE WESTERN PERIPHERY OF TY 07W-
-THESE SOLUTIONS ARE DEEMED UNLIKELY DUE TO THE 1000-NM SEPARATION
DISTANCE BETWEEN TD 11W AND TY 07W. GFS AND THE GFS ENSEMBLE SHOW
SOME WEAK INTERACTION WITH A DEVELOPING LOW IN THE NORTHERN SOUTH
CHINA SEA AND ARE SKEWED ON A MORE NORTHWESTWARD TRACK BEFORE
TRACKING NORTHWARD. HWRF AND THE ECMWF ENSEMBLE DEPICT A MORE
REALISTIC POLEWARD TRACK AND REASONABLE INTENSIFICATION RATE,
THEREFORE, THIS FORECAST FAVORS THOSE MODELS, ESPECIALLY HWRF. TD
11W IS EXPECTED TO INTENSIFY AT A CLIMATOLOGICAL RATE THROUGH TAU 72
TO 85 KNOTS.
C. IN THE EXTENDED FORECAST PERIOD, TD 11W IS FORECAST TO TURN
WESTWARD AS STEERING TRANSITIONS TO THE DEEP-LAYERED SUBTROPICAL
RIDGE ENTRENCHED OVER EASTERN CHINA AND WESTERN JAPAN. TD 11W IS
EXPECTED TO SLOW ITS INTENSIFICATION RATE AS IT BEGINS TO ENCOUNTER
INCREASING NORTHEASTERLY VERTICAL WIND SHEAR AND INTERACTS WITH THE
MOUNTAINOUS TERRAIN OF TAIWAN. OVERALL, THERE IS LOW CONFIDENCE
(HIGH UNCERTAINTY) IN THE JTWC FORECAST TRACK DUE TO THE WIDE SPREAD
(BIFURCATION) IN DYNAMIC MODEL SOLUTIONS.//
NNNN

[euro6208]

Up to 40 knots

99W ELEVEN 170726 0000 15.8N 128.2E WPAC 40 993

[dexterlabio]

Had doubts that this would grow into something significant, but now seeing this develop nicely makes me think Nesat can top off Noru.

[euro6208]

TPPN13 PGTW 260635

A. TROPICAL DEPRESSION 11W (ELEVEN)

B. 26/0600Z

C. 16.15N

D. 128.18E

E. FIVE/HMWRI8

F. T3.0/3.0 STT: D1.0/03HRS

G. IR/EIR/VIS/MSI

H. REMARKS: 40A/PBO SBC/ANMTN. .65 WRAP YIELDS A DT OF 3.0. PT
AND MET ARE CURRENTLY UNAVAILABLE. DBO DT. BROKE CONSTRAINTS
(CHANGE OF 0.5 OVER 6HRS) DUE TO THE OVERALL BETTER STRUCTURE
AND WRAPPING OF THE CONVECTION.

I. ADDITIONAL POSITIONS: NONE


MARTINEZ

[euro6208]

Aiming for Taipei.

WDPN34 PGTW 260900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL DEPRESSION 11W (ELEVEN)
WARNING NR 02//
RMKS//
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
TROPICAL STORM 11W (NESAT), LOCATED APPROXIMATELY 427 NM EAST-
NORTHEAST OF MANILA, PHILIPPINES, HAS TRACKED NORTHWARD AT 04
KNOTS OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE
IMAGERY DEPICTS A RAPIDLY CONSOLIDATING SYSTEM WITH DEEP CENTRAL
CONVECTION AND DENSE OVERCAST PARTIALLY OBSCURING THE LLCC. THE
INITIAL POSITON IS PLACED WITH FAIR CONFIDENCE BASED ON SATELLITE
FIXES. THE INITIAL INTENSITY ASSESSMENT OF 45 KNOTS IS BASED RECENT
DVORAK ESTIMATES OF T3.0 (45 KNOTS) AND ON A 260133Z METOP-B ASCAT
IMAGE SHOWING AN AREA OF 40 KNOT WINDS ON THE SOUTHEASTERN PERIPHERY
WITH A FEW EMBEDDED 45 KNOT BARBS. THE ASCAT IMAGE ALSO SHOWS THE
WIND FIELD MUCH MORE EXTENSIVE ON THE SOUTHERN PERIPHERY.
ENVIRONMENTAL CONDITIONS ARE CURRENTLY MARGINAL TO FAVORABLE WITH
ROBUST EQUATORWARD OUTFLOW UNDER VERY WARM (31 CELSIUS) BEING OFFSET
BY MODERATE NORTHERLY WIND SHEAR. CURRENTLY TS NESAT IS TRACKING
NORTHWARD ALONG A MID TO LOW LEVEL RIDGE TO THE EAST OF THE
SYSTEM.
3. FORECAST REASONING.
A. NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS
PROGNOSTIC REASONING MESSAGE.
B. TD 11W IS FORECAST TO TRACK NORTHWARD ALONG THE WESTERN
PERIPHERY OF THE STEERING RIDGE THROUGH TAU 48 BUT SHOULD TURN NORTH-
NORTHWESTWARD AND SLOW SLIGHTLY AS IT TRANSITIONS TO A SUBTROPICAL
RIDGE TO THE NORTH. ENVIRONMENTAL CONDITIONS ARE EXPECTED TO IMPROVE
SLIGHTLY ALLOWING TS NESAT TO STEADILY INTENSIFY OVER THE NEXT FEW
DAYS. DYNAMIC GUIDANCE IS SHOWING BETTER AGREEMENT OVER THE NEXT 72
HOURS AND THERE IS MUCH BETTER CONFIDENCE IN THE JTWC FORECAST
TRACK.
C. IN THE EXTENDED FORECAST PERIOD, TD 11W IS FORECAST TO TURN
WESTWARD AS STEERING TRANSITIONS TO THE DEEP-LAYERED SUBTROPICAL
RIDGE ENTRENCHED OVER EASTERN CHINA AND WESTERN JAPAN. TD 11W IS
EXPECTED TO SLOW ITS INTENSIFICATION RATE AS IT BEGINS TO ENCOUNTER
INCREASING NORTHEASTERLY VERTICAL WIND SHEAR. LAND INTERACTION OVER
THE MOUNTAINOUS TERRAIN OF TAIWAN WILL LEAD TO SIGNIFICANT WEAKENING
BY TAU 120. AVAILABLE MODEL GUIDANCE SHOWS DIVERGING SOLUTIONS IN
THE EXTENDED FORECAST WITH A POSSIBILITY OF TS NESAT RECURVING
NORTHEASTWARD DUE TO A WEAKENING NORTHERN RIDGE. OVERALL THERE IS
LOW CONFIDENCE IN THE FORECAST TRACK//
NNNN

[euro6208]

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

----- Current Analysis -----
Date : 26 JUL 2017 Time : 094000 UTC
Lat : 16:34:14 N Lon : 128:11:34 E


CI# /Pressure/ Vmax
2.8 / 997.2mb/ 41.0kt


Final T# Adj T# Raw T#
2.8 2.8 3.4

Center Temp : -57.0C Cloud Region Temp : -56.9C

Scene Type : IRREGULAR CDO*

Positioning Method : FORECAST INTERPOLATION

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

Tno/CI Rules : Constraint Limits : 0.7T/6hr
Weakening Flag : OFF
Rapid Dissipation Flag : OFF

C/K/Z MSLP Estimate Inputs :
- Average 34 knot radii : N/A
- Environmental MSLP : 1008mb

Satellite Name : HIM-8
Satellite Viewing Angle : 24.4 degrees

****************************************************

[euro6208]

Not only will this traverse over the warmest waters in the world, 31C, the pressure and wind speed maximum is phenomenal.

[NotoSans]

Somehow reminds me of Typhoon Matmo in 2014. I'm expecting similar peak and landfall intensity attm.

[euro6208]

Only 992 mb at landfall for Taiwan but things get crazier. Maybe a typhoon for Shanghai? (The world's largest city?).

[euro6208]

GFS 937 mb southern Taiwan.

[euro6208]

[euro6208]

TROPICAL DEPRESSION 11W ANALYSED POSITION : 16.0N 128.1E



VERIFYING TIME POSITION STRENGTH TENDENCY

-------------- -------- -------- --------

00UTC 26.07.2017 16.0N 128.1E WEAK

12UTC 26.07.2017 17.6N 128.2E WEAK LITTLE CHANGE

00UTC 27.07.2017 18.9N 128.6E MODERATE LITTLE CHANGE

12UTC 27.07.2017 19.5N 127.6E MODERATE LITTLE CHANGE

00UTC 28.07.2017 21.5N 127.5E MODERATE LITTLE CHANGE

12UTC 28.07.2017 22.2N 126.7E MODERATE LITTLE CHANGE

00UTC 29.07.2017 23.2N 126.2E MODERATE LITTLE CHANGE

12UTC 29.07.2017 23.9N 125.4E MODERATE LITTLE CHANGE

00UTC 30.07.2017 24.0N 125.8E MODERATE INTENSIFYING SLIGHTLY

12UTC 30.07.2017 24.3N 125.9E STRONG INTENSIFYING SLIGHTLY

00UTC 31.07.2017 24.1N 126.4E STRONG INTENSIFYING SLIGHTLY

12UTC 31.07.2017 23.9N 127.2E INTENSE INTENSIFYING SLIGHTLY

00UTC 01.08.2017 24.1N 128.7E INTENSE LITTLE CHANGE

[euro6208]

[NotoSans]

The latest Euro run shows Nesat interacting with another system in the South China Sea. Doesn't make much sense to me tbh.

[1900hurricane]

Looks like it's taking on the CCC pattern. Bands 9and 10 from Himawari- 8 seem to indicate some light northerly shear occurring below the anvil level. The latest GPM pass also seems to support.

[mrbagyo]

[euro6208]

WDPN34 PGTW 262100
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 11W (NESAT)
WARNING NR 04//
RMKS//
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
TROPICAL STORM 11W (NESAT), LOCATED APPROXIMATELY 421 NM EAST-
NORTHEAST OF MANILA, HAS TRACKED NORTHWARD AT 06 KNOTS OVER THE
PAST SIX HOURS. ANIMATED ENHANCED INFRARED SATELLITE IMAGERY
DEPICTS A CONSOLIDATING SYSTEM, WITH INTENSIFYING CENTRAL
CONVECTION. THE INITIAL POSITON IS PLACED WITH MODERATE CONFIDENCE
BASED ON SUBJECTIVE SATELLITE FIXES AND A NASCENT MICROWAVE EYE
FEATURE VISIBLE IN A 261631Z 37 GHZ GPM MICROWAVE IMAGE. THE
INITIAL OF 50 KNOTS IS SET SLIGHTLY HIGHER THAN DVORAK CURRENT
INTENSITY OF T3.0 FROM ALL AGENCIES IN LIGHT OF THE DEVELOPMENT OF
THE MICROWAVE EYE FEATURE AND THE GENERALLY IMPROVING DEPICTION OF
THE SYSTEM. ENVIRONMENTAL ANALYSIS INDICATES THE SYSTEM IS IN A
HIGHLY FAVORABLE AREA. TS 11W HAS MOVED INTO AN AREA WITH LOW (10-
15 KNOTS) VERTICAL WIND SHEAR (VWS), VERY HIGH SEA SURFACE
TEMPERATURES OF 31 DEG CELSIUS OR WARMER AND VERY HIGH OCEAN HEAT
CONTENT. THE SYSTEM LIES UNDER A SHARP UPPER LEVEL RIDGE AXIS, AND
THERE ARE HINTS OF A DEVELOPING POINT SOURCE, BUT FOR THE MOMENT
THE SYSTEM HAS ONLY ONE STRONG EQUATORWARD OUTFLOW CHANNEL, WHICH
IS LIMITING ITS INTENSIFICATION. TS 11W IS CURRENTLY TRACKING
NORTHWARD ALONG THE WESTERN EDGE OF A NORTH-SOUTH ORIENTED
EXTENSION OF THE SUBTROPICAL RIDGE (STR) TO THE EAST OF THE SYSTEM.
3. FORECAST REASONING.
A. NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS
PROGNOSTIC REASONING MESSAGE.
B. TS 11W IS FORECAST TO TRACK NORTHWARD ALONG THE WESTERN
PERIPHERY OF THE STEERING STR THROUGH TAU 24. BY TAU 36, THE SYSTEM
WILL BEGIN TRACKING MORE NORTHWESTERLY AS IT COMES UNDER THE
STEERING INFLUENCE OF A BUILDING STR OVER THE EAST CHINA SEA.
ENVIRONMENTAL CONDITIONS ARE EXPECTED TO REMAIN HIGHLY FAVORABLE,
WITH LOW VWS, HIGH SSTS AND STRONG OUTFLOW ALLOWING TS NESAT TO
STEADILY INTENSIFY, REACHING A PEAK INTENSITY OF 85 KNOTS AT TAU
48. AFTER TAU 48 HOWEVER, INCREASING VWS WILL COUNTERACT THE HIGH
SSTS AND SINGLE CHANNEL OUTFLOW, RESULTING IN A WEAKENING TREND
PRIOR TO LANDFALL.
C. IN THE EXTENDED FORECAST PERIOD, TS 11W IS FORECAST TO
CONTINUE TRACKING NORTHWESTWARD TOWARDS TAIWAN UNDER THE INFLUENCE
OF THE STR OVER THE EAST CHINA SEA. AFTER MAKING LANDFALL IN TAIWAN
JUST AFTER TAU 72, THE SYSTEM WILL SLOW SIGNIFICANTLY DUE TO
INTERACTION WITH THE MOUNTAINOUS TERRAIN, REEMERGING IN THE TAIWAN
STRAIT AROUND TAU 96 AND MAKING A SECOND LANDFALL OVER MAINLAND
CHINA BETWEEN TAUS 96 AND 120. SIMULTANEOUSLY, THE STEERING STR
WILL REORIENT TO A SHARP NORTH-SOUTH AXIS, STEERING TS 11W TOWARDS
THE NORTH AS IT CROSS INTO CHINA. TS 11W IS FORECAST TO STILL BE A
TYPHOON UPON MAKING LANDFALL IN CENTRAL TAIWAN, BUT WILL RAPIDLY
WEAKEN DUE TO TERRAIN INTERACTION AND REAPPEARING IN THE TAIWAN
STRAIT AS A WEAK TROPICAL STORM. DYNAMIC MODEL GUIDANCE HAS SHOWN
DECREASING SPREAD OVER THE PAST SIX HOURS, WITH ALL MODELS NOW IN
GOOD AGREEMENT ON THE FORECAST TRACK THROUGH LANDFALL, WITH
SIGNIFICANT UNCERTAINTY IN THE LATER TAUS, AFTER LANDFALL. OVERALL
THERE IS HIGH CONFIDENCE IN THE FORECAST TRACK.//
NNNN

[mrbagyo]

bulk of convection is displaced by northerly shear

[wxmann_91]

GFS shear projections do not look favorable for Nesat through landfall in Taiwan. Not sure why it strengthens this so much.

[doomhaMwx]

Now a Severe TS by JMA...


There is good agreement among the warning agencies that it will make landfall somewhere in Taiwan as a Typhoon this coming weekend...