WPAC: NANMADOL - Post-Tropical

[euro6208]

Another weak short lived system.

[1900hurricane]

I haven't been watching Nanmadol extremely closely today until the past two hours or so, but it wouldn't surprise me if it was already a moderate strength tropical storm right now, just based on current satellite presentation. JMA probably has the leg up on JTWC at the moment with the tropical storm classification (vs a TD). Still awaiting ASCAT.

[euro6208]

WDPN31 PGTW 020300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL DEPRESSION 05W (NANMADOL)
WARNING NR 01//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
TROPICAL DEPRESSION 05W (NANMADOL), LOCATED APPROXIMATELY 351 NM
SOUTH OF KADENA AB, HAS TRACKED NORTH-NORTHWESTWARD AT 22 KNOTS
OVER THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED SATELLITE
IMAGERY DEPICTS A RAPIDLY CONSOLIDATING SYSTEM WITH FORMATIVE
BANDING AND SIGNIFICANT MID-LEVEL TURNING. THE INITIAL POSITION IS
BASED ON AGENCY SATELLITE FIXES, BUT WITH LOW CONFIDENCE DUE TO A
BROAD LOW LEVEL CIRCULATION STILL CONSOLIDATING EVIDENCED IN RECENT
SATELLITE AND MICROWAVE IMAGERY. THE INITIAL INTENSITY ASSESSMENT OF
30 KNOTS IS BASED ON MULTI-AGENCY DVORAK ESTIMATES RANGING FROM T1.0-
T2.0 (25 TO 30 KNOTS). A 011259Z METOP-B ASCAT IMAGE SHOWS A REGION
OF STRONGER GRADIENT WINDS TO THE NORTHEAST OF THE SYSTEM. UPPER-
LEVEL CONDITIONS ARE CURRENTLY FAVORABLE AS A TUTT CELL JUST TO THE
WEST OF THE SYSTEM HAS AIDED OUTFLOW OVER THE LAST SIX HOURS, AND
WIND SHEAR VALUES ARE LOW. SSTS IN THE REGION ARE ALSO VERY WARM
NEAR 30 CELSIUS. A DEEP-LAYER SUBTROPICAL RIDGE TO THE NORTHEAST IS
CURRENTLY STEERING TD 05W ON A NORTH-NORTHWESTWARD TRACK.
3. FORECAST REASONING.
A. THIS IS THE INITIAL FORECAST AND SETS THE FORECAST PHILOSOPHY
FOR THIS SYSTEM.
B. THE SUBTROPICAL RIDGE WILL STEER TD 05W NORTHWARD OVER THE
NEXT 12 TO 24 HOURS BEFORE ROUNDING THE RIDGE AXIS AND ACCELERATING
TO THE NORTHEAST. TD 05W IS EXPECTED TO INTENSIFY OVER THE NEXT 24
HOURS AS AN APPROACHING UPPER-LEVEL TROUGH FROM THE WEST WILL
ENHANCE OUTFLOW. BEYOND TAU 24 SSTS WILL DROP SIGNIFICANTLY AND WIND
SHEAR WILL BEGIN TO INCREASE AS TD 05W INTERACTS WITH THE WESTERLIES
ASSOCIATED WITH THE TROUGH. TD 05W WILL TRANSITION TO AN
EXTRATROPICAL SYSTEM AS IT TRACKS ACROSS HONSHU BECOMING FULLY
EXTRATROPICAL BY TAU 72. DYNAMIC MODEL GUIDANCE SHOWS VERY TIGHT
AGREEMENT, LENDING HIGH CONFIDENCE TO THE FORECAST TRACK.//
NNNN

[1900hurricane]

Big difference in Dvorak fixes between JTWC and SAB. I'm more inclined to agree with SAB.

TPPN10 PGTW 020303

A. TROPICAL DEPRESSION 05W (NANMADOL)

B. 02/0230Z

C. 21.25N

D. 126.55E

E. FIVE/HMWRI8

F. T1.5/1.5/D0.5/24HRS STT: D0.5/03HRS

G. IR/EIR/VIS/MSI

H. REMARKS: 40A/PBO SBC/ANMTN. CNVCTN WRAPS .35 ON LOG10 SPIRAL
YIELDING A DT OF 1.5. MET AND PT YIELD 1.5. DBO DT OF 1.5.

I. ADDITIONAL POSITIONS: NONE


LOWE

TXPQ28 KNES 020305
TCSWNP

A. 05W (NANMADOL)

B. 02/0230Z

C. 21.5N

D. 125.9E

E. THREE/HIMAWARI-8

F. T2.5/2.5/D2.0/24HRS

G. IR/EIR/VIS

H. REMARKS...6/10 BANDING RESULTS IN A DT OF 3.0. MET IS 1.5 BASED
ON RAPID DEVELOPMENT OVER THE LAST 24 HOURS AND THE PT IS ADJUSTED TO
2.0. FT IS BASED ON CONSTRAINTS, WHICH RESTRICT THE FT TO NO MORE THAN
2.5 24 HOURS AFTER THE INITIAL T1.0.

I. ADDL POSITIONS

NIL


...TURK

[1900hurricane]

METOB-B is showing solid structure.



It also appears that a couple of good inflow bands are streaming in from the south. Palau appears to be very near one of them around 00Z, so it is no surprise that the 00Z PTRO sounding shows good low level moisture, especially below 700 mb. That sounding is also sampling Nanmadol's equatorial outflow channel.

[Alyono]

how does JTWC get a 1.5 when there is a formative banding eye on visible?

I do not understand how one messes up a Dvorak estimate that badly

[euro6208]

CIMSS AMSU: 1005 hPa 34 knots

[doomhaMwx]

Unfortunately, the latest ASCAT pass missed the center. Only caught that band in the eastern semicircle...

[Alyono]

CIMSS AMSU: 1005 hPa 34 knots

probably using the JTWC forecast interpolation, which is a BS way of making an ADT

[1900hurricane]

how does JTWC get a 1.5 when there is a formative banding eye on visible?

I do not understand how one messes up a Dvorak estimate that badly

SAB's 6/10 banding continues to look good. I as well am not sure how JTWC got .35.

[euro6208]

Really intense convection showing up on radar.

[1900hurricane]

 https://twitter.com/EarthUncutTV/status/881367805781696512

[euro6208]

Impressive system that's only classified as a weak TD/TS. That looks very much like a typhoon or very close to one.

[euro6208]

05W NANMADOL 170702 0600 22.1N 125.6E WPAC 35 996

Also up to 35 knots now.

[Yellow Evan]

WP, 05, 2017070206, , BEST, 0, 220N, 1257E, 35, 1005, TS, 34, NEQ, 90, 80, 45, 60, 1008, 170, 35, 0, 0, W, 0, , 0, 0, NANMADOL, S,

Still a bit too low lol

[euro6208]

Agencies busting big time. It's clearly a typhoon now.

[mrbagyo]

Agencies busting big time. It's clearly a typhoon now.

surprise surprise.
That's clearly an eye.


Northern periphery of the eye still looks open in vis imagery - but it's clearly there.

[euro6208]

WDPN31 PGTW 020900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 05W (NANMADOL)
WARNING NR 02//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
TROPICAL STORM (TS) 05W (NANMADOL), LOCATED APPROXIMATELY 293 NM
SOUTH-SOUTHWEST OF KADENA AB, HAS TRACKED NORTHWESTWARD AT 17 KNOTS
OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY
DEPICTS A CONSOLIDATING LOW-LEVEL CIRCULATION CENTER WITH TIGHTLY-
WRAPPED CONVECTIVE BANDING WRAPPING INTO A WELL-DEFINED CENTER.
DESPITE THE IMPROVED OVERALL CONVECTIVE STRUCTURE, DEEP CONVECTION
HAS CONTINUED TO CYCLE RAPIDLY ALONG THE FRAGMENTED DEEP CONVECTIVE
BANDS. ANIMATED RADAR IMAGERY FROM THE MIYAKO-JIMA RADAR SHOWS A
WELL-DEFINED, SHALLOW (LIGHT TO MODERATE RAINFALL), AND COMPACT
EYEWALL. ADDITIONALLY, A 020545Z SSMI 85GHZ IMAGE SHOWS IMPROVED
CONVECTIVE BANDING AND CORE CONVECTION. OVERALL, THERE IS GOOD
CONFIDENCE IN THE CURRENT POSITION AND RECENT TRACK MOTION. UPPER-
LEVEL ANALYSIS CONTINUES TO INDICATE ROBUST OUTFLOW AND FAVORABLE
ENVIRONMENTAL CONDITIONS TO INCLUDE LOW VERTICAL WIND SHEAR. SST
VALUES ARE FAVORABLE AT 30 TO 31C. TS 05W IS TRACKING QUICKLY
POLEWARD ALONG THE WESTERN EDGE OF THE DEEP SUBTROPICAL RIDGE (STR).
3. FORECAST REASONING.
A. THERE IS NO SIGNIFICANT CHANGE TO THE FORECAST PHILOSOPHY,
HOWEVER, PEAK INTENSITY HAS BEEN INCREASED TO 55 KNOTS.
B. TS 05W IS FORECAST TO CONTINUE TO TRACK POLEWARD ALONG THE
WESTERN PERIPHERY OF THE STR THROUGH TAU 24. ENVIRONMENTAL
CONDITIONS REMAIN FAVORABLE, THEREFORE, 05W IS EXPECTED TO INTENSIFY
TO A PEAK OF 55 KNOTS BY TAU 24. THERE IS SOME UNCERTAINTY IN THE
PEAK INTENSITY WITH SOME GUIDANCE INDICATING A PEAK OF 65 KNOTS. THE
BULK OF THE RELIABLE INTENSITY GUIDANCE RANGES FROM 45 TO 57 KNOTS,
INCLUDING HWRF, WHICH PEAKS AT 57 KNOTS. BY TAU 36, THE SYSTEM IS
FORECAST TO RE-CURVE AND ACCELERATE NORTHEASTWARD AS IT BEGINS EXTRA-
TROPICAL TRANSITION (ETT) WHILE INTERACTING WITH THE MIDLATITUDE
WESTERLIES. AFTER TAU 48, TS 05W WILL ACCELERATE EAST-NORTHEASTWARD
WITHIN ZONAL WESTERLY FLOW AND IS EXPECTED TO COMPLETE ETT BY TAU 72
AS IT TRACKS ACROSS HONSHU AND WEAKENS SIGNIFICANTLY. THE DYNAMIC
AIDS ARE IN UNUSUALLY TIGHT AGREEMENT FOR A RE-CURVE SCENARIO
LENDING HIGH CONFIDENCE TO THE FORECAST TRACK.//
NNNN

[Digital-TC-Chaser]

likely to be 64kts on sat appearance.

[euro6208]

First typhoon of the season is here and the agencies are ignoring radar let alone satellite imagery. Hate to say it but both JTWC and JMA disappoints. They also like to ignore ASCAT for many other systems.