WPAC: NALGAE - Post-Tropical

[euro6208]

:uarrow: ASCAT only shows 25kt winds for this one but at least 30kt winds for Emily.

So maybe 35 knots for 13W and 40 knots for Emily?

Gotta remember ASCAT was never mentioned when this was upgraded to a TS on the 2nd warning until the 6th and was only mentioned before and after the upgrade.

Underestimated.

[euro6208]

WDPN31 PGTW 012100
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL DEPRESSION 13W (THIRTEEN)
WARNING NR 04//
RMKS//
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
TROPICAL DEPRESSION 13W (THIRTEEN), LOCATED APPROXIMATELY 377 NM
NORTH-NORTHWEST OF WAKE ISLAND, HAS TRACKED EASTWARD AT 07 KNOTS
OVER THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED SATELLITE
IMAGERY SHOWS FLARING CONVECTION SHEARED TO THE EAST OF A PARTIALLY
EXPOSED LOW LEVEL CIRCULATION CENTER (LLCC). THE INITIAL POSITION IS
PLACED WITH HIGH CONFIDENCE BASED ON THE PGTW SATELLITE FIX POSITION
LLCC. A 011726Z SSMIS 91 GHZ MICROWAVE IMAGE DEPICTS WEAK CONVECTIVE
BANDING INTO THE LLCC WITH ALL DEEP CONVECTION LIMITED TO A NORTH-
SOUTH ORIENTED BAND ALONG THE EASTERN PERIPHERY OF THE SYSTEM. THE
INITIAL INTENSITY IS ASSESSED AT 30 KNOTS AND IS BASED ON MULTI
AGENCY DVORAK ESTIMATES RANGING FROM T1.0 TO T1.5 (25KTS), EDGED
SLIGHTLY HIGHER BASED ON A 011038Z METOP-B ASCAT IMAGE SHOWING A
SMALL AREA OF 30 KNOT WINDS IN THE NORTHEAST SECTOR. TD 13W LIES IN
AREA OF MODERATE TO HIGH (20-25 KNOTS) VERTICAL WIND SHEAR (VWS) AND
WARM SEA SURFACE TEMPERATURES (SST) (28 DEG CELSIUS). WHILE THE
SYSTEM IS STILL TAPPING INTO A MODERATELY STRONG EQUATORWARD OUTFLOW
CHANNEL, THIS IS BEING OFFSET BY THE HIGH VWS. TD 13W IS TRACKING
EASTWARD UNDER THE INFLUENCE OF A NORTHWARD-DISPLACED NEAR
EQUATORIAL RIDGE (NER) LOCATED TO THE SOUTHWEST.
3. FORECAST REASONING.
A. NO CHANGE TO THE FORECAST TRACK PHILOSOPHY SINCE THE PREVIOUS
PROGNOSTIC REASONING MESSAGE.
B. TD 13W WILL BECOME NEARLY QUASI-STATIONARY BY TAU 12 AS A
STRONG NORTH-SOUTH ORIENTED BLOCKING RIDGE DEVELOPS ALONG THE
DATELINE, BLOCKING ANY FURTHER EASTWARD MOVEMENT. THIS BLOCKING
PATTERN BECOMES THE DOMINATE STEERING MECHANISM THROUGH TAU 72.
AFTER COMPLETING THIS TURN TO THE NORTH, TD 13W WILL ACCELERATE
NORTHWARDS AND CONTINUE THIS TRACK FOR THE DURATION OF THE FORECAST
PERIOD. TD 13W WILL CONTINUE TO STEADILY INTENSIFY FOR THE NEXT 48
HOURS AS VWS DECREASES, EQUATORWARD OUTFLOW INCREASES AND THE SYSTEM
REMAINS OVER WARM WATERS. AFTER PEAKING AT TAU 48 THE SYSTEM WILL
START A SLOW WEAKENING TREND AS IT BEGINS TO TRACK OVER
PROGRESSIVELY COOLER WATERS, AND THE EQUATORWARD OUTFLOW CHANNEL IS
CUT OFF. DYNAMIC MODEL GUIDANCE IS IN STRONG AGREEMENT THAT THE
SYSTEM WILL TURN TO THE NORTH WITH LARGE DISPARITIES AS TO THE EXACT
TIMING AND SHARPNESS OF THE TURN, LEADING TO LOW CONFIDENCE IN THIS
PORTION OF THE FORECAST TRACK.
C. AFTER TAU 72, TD 13W IS FORECAST TO CONTINUE TRACKING NORTH-
NORTHWESTWARD ALONG THE WESTERN PERIPHERY OF A STRONG STR LOCATED TO
THE EAST. THE SYSTEM WILL BEGIN TO WEAKEN AFTER TAU 72 AS IT STARTS
TO TRACK UNDERNEATH AN UPPER-LEVEL LOW, LOSE ITS SOURCE OF OUTFLOW
AND BEGIN EXTRA-TROPICAL TRANSITION. THE SYSTEM IS FORECAST TO
COMPLETE EXTRA-TROPICAL TRANSITION BY TAU 96 AS IT MOVES BENEATH AN
UPPER-LEVEL MID-LATITUDE LOW. MODEL GUIDANCE IS IN AGREEMENT THAT
THE TRACK WILL CONTINUE TO THE NORTH-NORTHWESTWARD, BUT WITH LARGE
SPREAD IN THE EXACT TRACK BASED ON THE STRENGTH AND ORIENTATION OF
THE BLOCKING RIDGE TO THE EAST. DUE TO THE INCREASED MODEL SPREAD,
THERE IS OVERALL LOW CONFIDENCE IN THIS PORTION OF THE JTWC TRACK
FORECAST.//
NNNN

[euro6208]

[1900hurricane]

JMA has named Tropical Storm Nalgae.

TS 1711 (Nalgae)
Issued at 01:15 UTC, 2 August 2017

<Analysis at 00 UTC, 2 August>
Scale -
Intensity -
Center position N25°25' (25.4°)
E165°40' (165.7°)
Direction and speed of movement ESE 15 km/h (9 kt)
Central pressure 998 hPa
Maximum wind speed near center 18 m/s (35 kt)
Maximum wind gust speed 25 m/s (50 kt)
≥ 30 kt wind area S 330 km (180 NM)
N 220 km (120 NM)

<Forecast for 12 UTC, 2 August>
Intensity -
Center position of probability circle N25°40' (25.7°)
E166°00' (166.0°)
Direction and speed of movement NE Slow
Central pressure 998 hPa
Maximum wind speed near center 18 m/s (35 kt)
Maximum wind gust speed 25 m/s (50 kt)
Radius of probability circle 60 km (30 NM)

<Forecast for 00 UTC, 3 August>
Intensity -
Center position of probability circle N26°50' (26.8°)
E165°00' (165.0°)
Direction and speed of movement NW 15 km/h (7 kt)
Central pressure 998 hPa
Maximum wind speed near center 18 m/s (35 kt)
Maximum wind gust speed 25 m/s (50 kt)
Radius of probability circle 90 km (50 NM)

<Forecast for 00 UTC, 4 August>
Intensity -
Center position of probability circle N28°30' (28.5°)
E163°20' (163.3°)
Direction and speed of movement NW 15 km/h (7 kt)
Central pressure 996 hPa
Maximum wind speed near center 20 m/s (40 kt)
Maximum wind gust speed 30 m/s (60 kt)
Radius of probability circle 180 km (95 NM)

<Forecast for 00 UTC, 5 August>
Intensity -
Center position of probability circle N31°30' (31.5°)
E162°55' (162.9°)
Direction and speed of movement N 15 km/h (8 kt)
Central pressure 992 hPa
Maximum wind speed near center 23 m/s (45 kt)
Maximum wind gust speed 35 m/s (65 kt)
Radius of probability circle 240 km (130 NM)

[doomhaMwx]

Nalgae is already the 6th named storm to form/develop in the NW Pacific while Noru is still active, which is a new record according to Digital-Typhoon...

[euro6208]

WDPN33 PGTW 020300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL DEPRESSION 13W (NALGAE)
WARNING NR 05//
RMKS//
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
TROPICAL DEPRESSION 13W (NALGAE), LOCATED APPROXIMATELY 392 NM
NORTH OF WAKE ISLAND, HAS TRACKED NORTHEASTWARD AT 07 KNOTS OVER THE
PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY SHOWS
FLARING CONVECTION CONSOLIDATING OVER A PARTIALLY EXPOSED LOW LEVEL
CIRCULATION CENTER (LLCC). THE INITIAL POSITION IS PLACED WITH HIGH
CONFIDENCE BASED ON THE PGTW SATELLITE FIX POSITION. A 012303Z AMSU
89 GHZ MICROWAVE IMAGE CONFIRMS THE POSITION FIX AND DEPICTS DEEP
CONVECTIVE BANDING INTO THE LLCC FROM THE SOUTHERN AND EASTERN
QUADRANTS. THE INITIAL INTENSITY IS ASSESSED AT 30 KNOTS AND IS ON
THE UPPER END OF MULTI AGENCY DVORAK ESTIMATES OF T1.5 TO T2.0 (25
TO 30 KNOTS) BASED ON A 012303Z SCATTEROMETER PASS SHOWING A BROAD
AREA OF 30 KNOT WINDS ALONG THE SOUTHEASTERN PERIPHERY, WITH SOME 30
KNOT WINDS INDICATED WRAPPING IN ALONG THE NORTHERN EDGE AS WELL. TD
13W LIES IN AREA OF LOW TO MODERATE (15-20 KNOTS) VERTICAL WIND
SHEAR (VWS) AND WARM SEA SURFACE TEMPERATURES (SST) (27-28 DEG
CELSIUS). THE SYSTEM IS TAPPING INTO A ROBUST EASTERLY OUTFLOW
CHANNEL INTO A TUTT CELL NEAR THE DATELINE. TD 13W IS TRACKING
NORTHEASTWARD ALONG THE NORTHWESTERN BOUNDARY OF A NEAR EQUATORIAL
RIDGE (NER) LOCATED TO THE SOUTHEAST.
3. FORECAST REASONING.
A. NO CHANGE TO THE FORECAST TRACK PHILOSOPHY SINCE THE PREVIOUS
PROGNOSTIC REASONING MESSAGE.
B. TD 13W WILL SLOW SIGNIFICANTLY, BECOMING NEARLY QUASI-
STATIONARY OVER THE NEXT 12 HOURS, AS A STRONG NORTH-SOUTH ORIENTED
BLOCKING RIDGE DEVELOPS ALONG THE DATELINE, BLOCKING FURTHER
EASTWARD MOVEMENT. THIS BLOCKING RIDGE BECOMES THE PRIMARY STEERING
MECHANISM AFTER TAU 24, PUSHING TD 13W ONTO A NORTH THEN
NORTHWESTWARD TRACK FROM TAU 24 THROUGH TAU 72. TD 13W WILL CONTINUE
TO STEADILY INTENSIFY THROUGH TAU 48 AS VWS CONTINUES TO DECREASE,
EASTWARD OUTFLOW REMAINS IN PLACE AND THE SYSTEM TRACKS OVER WARM
WATERS 26-28 DEG C). AFTER PEAKING AT TAU 48 THE SYSTEM WILL START A
SLOW WEAKENING TREND AS IT BEGINS TO TRACK OVER PROGRESSIVELY COOLER
WATERS, AND THE EASTWARD OUTFLOW CHANNEL DISSIPATES. THE SYSTEM IS
FORECAST TO BEGIN EXTRATROPICAL TRANSITION BY TAU 72, AS IT
INTERACTS WITH A DEEP UPPER-LEVEL TROUGH DIGGING SOUTHWARDS AND
STARTS TO LOSE ITS TROPICAL CHARACTERISTICS. DYNAMIC MODEL GUIDANCE
IS IN STRONG AGREEMENT THAT THE SYSTEM WILL TURN TO THE NORTH BUT
THERE REMAIN RELATIVELY MINOR VARIANCES IN THE EXACT TIMING AND
SHARPNESS OF THE TURN. OVERALL THERE IS HIGH CONFIDENCE IN THIS
PORTION OF THE FORECAST TRACK.
C. AFTER TAU 72, TD 13W IS FORECAST TO CONTINUE TRACKING NORTH-
NORTHWESTWARD ALONG THE WESTERN PERIPHERY OF A STRONG STR LOCATED TO
THE EAST. THE SYSTEM WILL BEGIN TO WEAKEN AFTER TAU 72 AS IT STARTS
TO TRACK UNDERNEATH AN UPPER-LEVEL LOW, LOSE ITS SOURCE OF OUTFLOW
AND COMPLETE EXTRA-TROPICAL TRANSITION BY TAU 96 AS IT BECOMES
ABSORBED INTO A BROAD AND DEEP UPPER-LEVEL LOW SYSTEM. MODEL
GUIDANCE IS IN AGREEMENT THAT THE TRACK WILL CONTINUE TO THE NORTH-
NORTHWESTWARD, WITH A LARGE SPREAD IN THE EXACT TRACK BASED ON THE
STRENGTH AND ORIENTATION OF THE BLOCKING RIDGE TO THE EAST. DUE TO
THE INCREASED MODEL SPREAD, THERE IS OVERALL LOW CONFIDENCE IN THIS
PORTION OF THE JTWC TRACK FORECAST.//
NNNN

[euro6208]

WDPN33 PGTW 020900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL DEPRESSION 13W (NALGAE)
WARNING NR 06//
RMKS//
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
TROPICAL DEPRESSION 13W (NALGAE), LOCATED APPROXIMATELY 401 NM
NORTH OF WAKE ISLAND, HAS TRACKED NORTHEASTWARD AT 03 KNOTS OVER
THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY SHOWS
PERSISTENT CONVECTION WRAPPING INTO A PARTIALLY EXPOSED LOW LEVEL
CIRCULATION CENTER (LLCC). THE INITIAL POSITION IS PLACED WITH HIGH
CONFIDENCE BASED ON THE PGTW SATELLITE FIX POSITION. A 020444Z SSMIS
91 GHZ MICROWAVE IMAGE SUPPORTS THE INITIAL POSITION AND DEPICTS
DEEP CONVECTION, PREDOMINANTLY IN THE EASTERN SEMI CIRCLE. THE
INITIAL INTENSITY ASSESSMENT OF 30 KNOTS IS BASED ON MULTI AGENCY
DVORAK ESTIMATES T2.0 (30 KNOTS). ENVIRONMENTAL ANALYSIS SHOWS THAT
TD 13W IS CURRENTLY LOCATED IN AN AREA OF MODERATE (15-20 KNOTS)
VERTICAL WIND SHEAR (VWS) AND IS TRACKING THROUGH WARM SEA SURFACE
TEMPERATURES (SST) (27-28 CELSIUS). THE SYSTEM IS CURRENTLY
EXPERIENCING ENHANCED EQUATORWARD OUTFLOW AS A RESULT OF THE TUTT
CELL LOCATED TO THE EAST. TD 13W IS TRACKING VERY SLOWLY
NORTHEASTWARD ALONG THE NORTHWESTERN BOUNDARY OF A NEAR EQUATORIAL
RIDGE (NER) LOCATED TO THE SOUTHEAST.
3. FORECAST REASONING.
A. NO CHANGE TO THE FORECAST TRACK PHILOSOPHY SINCE THE PREVIOUS
PROGNOSTIC REASONING MESSAGE.
B. TD 13W WILL REMAIN NEARLY QUASI-STATIONARY OVER THE NEXT 12
HOURS WHILE THE TRACK DIRECTION CHANGES FROM NORTHEAST TO NORTHWEST.
THE QUASI-STATIONARY MOTION IS THE RESULT OF A STRONG BLOCKING
RIDGE, ORIENTED NORTH-SOUTH, BUILDING TO THE EAST OF THE SYSTEM. THE
BLOCKING RIDGE IS INHIBITING FURTHER MOTION TO THE EAST AND CAUSING
THE STORM TO TURN BACK TO THE NORTHWEST. AFTER TAU 12 THE BLOCKING
RIDGE BECOMES THE PRIMARY STEERING FEATURE AS IT CAUSES THE SYSTEM
TO INITIALLY TRACK TO THE NORTH AND EVENTUALLY NORTHWEST BY TAU 24.
TD 13W WILL CONTINUE TO INTENSIFY THROUGH TAU 48 AS VWS VALUES
REMAIN LOW, THE SYSTEM IS OVER WARM SSTS, AND THE EQUATORWARD
OUTFLOW CHANNEL WILL BE ENHANCED BY THE TUTT TO THE EAST. AFTER TAU
48 THE SYSTEM WILL START A GRADUAL WEAKENING TREND AS IT TRACKS INTO
AN AREA OF COOLER SSTS AND THE OUTFLOW CHANNEL DISSIPATES. AFTER TAU
48 THE SYSTEM WILL BEGIN TROPICAL TRANSITION AS IT BEGINS TO
INTERACT WITH AN UPPER LEVEL TROUGH DEEPENING TO THE SOUTH. DYNAMIC
MODEL GUIDANCE REMAINS IN STRONG AGREEMENT THAT TD 13W WILL TURN TO
THE NORTHWEST, HOWEVER, SOME VARIATION REMAINS IN THE TIMING AND
SHARPNESS OF THE TURN. OVERALL THERE IS HIGH CONFIDENCE IN THIS
PORTION OF THE FORECAST TRACK.
C. AFTER TAU 72, TD 13W WILL CONTINUE TO TRACK TO THE NORTHWEST
ALONG THE WESTERN PERIPHERY OF A STR LOCATED TO THE NORTHEAST. THE
SYSTEM WILL ALSO BEGIN EXTRA-TROPICAL TRANSITION WHICH WILL BE
COMPLETE BY TAU 96 AS TD 13W IS ABSORBED INTO AN UPPER LEVEL TROUGH.
THE UPPER LEVEL TROUGH WILL ALSO CAUSE THE SYSTEM TO GRADUALLY
WEAKEN AFTER TAU 72 AS IT INHIBITS OUTFLOW. DYNAMIC MODEL IS IN
STRONG AGREEMENT THAT THE SYSTEM WILL CONTINUE TO TRACK TO THE NORTH
NORTHWEST FOR THE DURATION OF THE FORECAST PERIOD, HOWEVER,
VARIATION IN THE SIZE AND POSITION OF THE SUBTROPICAL STEERING RIDGE
ARE CAUSING A SIGNIFICANT SPREAD IN THE FORECAST TRACKS. THE SPREAD
IN MODEL FORECAST TRACKS LENDS LOW CONFIDENCE IN THIS PORTION OF THE
JTWC FORECAST TRACK.//
NNNN

[euro6208]

Center displaced southwest of the deepest convection. Looks like a high end TS if you ask me.

[euro6208]

13W NALGAE 170802 1200 26.6N 165.8E WPAC 35 999

[euro6208]

TPPN11 PGTW 021222

A. TROPICAL STORM 13W (NALGAE)

B. 02/1200Z

C. 26.60N

D. 165.89E

E. FIVE/HMWRI8

F. T2.5/2.5 STT: D0.5/03HRS

G. IR/EIR

H. REMARKS: 38A/PBO SBC/ANMTN. .45 WRAP ON LOG10 SPIRAL YIELDS
2.5 DT. MET/PT 2.5. DBO DT.

I. ADDITIONAL POSITIONS: NONE


DAVIS

TXPQ25 KNES 020905
TCSWNP

A. 13W (NALGAE)

B. 02/0830Z

C. 26.1N

D. 165.4E

E. THREE/HIMAWARI-8

F. T2.5/2.5/D1,5/24HRS

G. IR/EIR/SWIR/WINDSAT

H. REMARKS...DT=2.5 BASED ON CLASSICAL SHEAR PATTERN WITH LOW LEVEL
CENTER LESS THAN .75 DG FROM OVERCAST. PT=2.5. MET=2.5. FT IS BASED ON DT.

I. ADDL POSITIONS

02/0631Z 25.6N 165.5E WINDSAT


...SCHWARTZ

[Sciencerocks]

WTPN33 PGTW 030300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE WARNING//
RMKS/
1. TROPICAL STORM 13W (NALGAE) WARNING NR 009
02 ACTIVE TROPICAL CYCLONES IN NORTHWESTPAC
MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
WIND RADII VALID OVER OPEN WATER ONLY
---
WARNING POSITION:
030000Z --- NEAR 26.6N 164.8E
MOVEMENT PAST SIX HOURS - 300 DEGREES AT 04 KTS
POSITION ACCURATE TO WITHIN 020 NM
POSITION BASED ON CENTER LOCATED BY SATELLITE
PRESENT WIND DISTRIBUTION:
MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 034 KT WINDS - 030 NM NORTHEAST QUADRANT
030 NM SOUTHEAST QUADRANT
025 NM SOUTHWEST QUADRANT
035 NM NORTHWEST QUADRANT
REPEAT POSIT: 26.6N 164.8E
---
FORECASTS:
12 HRS, VALID AT:
031200Z --- 27.4N 164.0E
MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 034 KT WINDS - 045 NM NORTHEAST QUADRANT
045 NM SOUTHEAST QUADRANT
040 NM SOUTHWEST QUADRANT
050 NM NORTHWEST QUADRANT
VECTOR TO 24 HR POSIT: 320 DEG/ 05 KTS
---
24 HRS, VALID AT:
040000Z --- 28.1N 163.3E
MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 034 KT WINDS - 065 NM NORTHEAST QUADRANT
065 NM SOUTHEAST QUADRANT
060 NM SOUTHWEST QUADRANT
065 NM NORTHWEST QUADRANT
VECTOR TO 36 HR POSIT: 340 DEG/ 05 KTS
---
36 HRS, VALID AT:
041200Z --- 29.1N 162.9E
MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 034 KT WINDS - 065 NM NORTHEAST QUADRANT
065 NM SOUTHEAST QUADRANT
060 NM SOUTHWEST QUADRANT
065 NM NORTHWEST QUADRANT
VECTOR TO 48 HR POSIT: 355 DEG/ 11 KTS
---
EXTENDED OUTLOOK:
48 HRS, VALID AT:
050000Z --- 31.3N 162.7E
MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT
WIND RADII VALID OVER OPEN WATER ONLY
BECOMING EXTRATROPICAL
RADIUS OF 034 KT WINDS - 070 NM NORTHEAST QUADRANT
065 NM SOUTHEAST QUADRANT
060 NM SOUTHWEST QUADRANT
065 NM NORTHWEST QUADRANT
VECTOR TO 72 HR POSIT: 350 DEG/ 17 KTS
---
72 HRS, VALID AT:
060000Z --- 37.9N 161.1E
MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT
WIND RADII VALID OVER OPEN WATER ONLY
EXTRATROPICAL
RADIUS OF 034 KT WINDS - 045 NM NORTHEAST QUADRANT
040 NM SOUTHEAST QUADRANT
040 NM SOUTHWEST QUADRANT
040 NM NORTHWEST QUADRANT
---
REMARKS:
030300Z POSITION NEAR 26.8N 164.6E.
TROPICAL STORM 13W (NALGAE), LOCATED APPROXIMATELY 449 NM NORTH-
NORTHWEST OF WAKE ISLAND, HAS TRACKED WEST-NORTHWESTWARD AT 04
KNOTS OVER THE PAST SIX HOURS.
MAXIMUM SIGNIFICANT WAVE HEIGHT AT 030000Z IS 12 FEET. NEXT
WARNINGS AT 030900Z, 031500Z, 032100Z AND 040300Z.
REFER TO TYPHOON 07W (NORU) WARNINGS (WTPN31 PGTW)
FOR SIX-HOURLY UPDATES.
//
NNNN

[euro6208]

WDPN33 PGTW 030900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 13W (NALGAE)
WARNING NR 10//
RMKS//
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
TROPICAL STORM (TS) 13W (NALGAE), LOCATED APPROXIMATELY 521 NM
NORTH-NORTHWEST OF WAKE ISLAND, HAS TRACKED NORTH-NORTHWESTWARD AT 12
KNOTS OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE
IMAGERY DEPICTS A BROAD, PARTIALLY-EXPOSED LOW-LEVEL CIRCULATION
CENTER (LLCC) WITH ISOLATED CONVECTIVE BANDING OVER THE EASTERN SEMI-
CIRCLE. DESPITE THE LIMITED DEEP CONVECTIVE BANDING, A 030431Z SSMIS
37GHZ COMPOSITE IMAGE SHOWS SHALLOW BANDING WRAPPING INTO A DEFINED,
OBLONG CENTER, WHICH SUPPORTS THE INITIAL POSITION WITH GOOD
CONFIDENCE. THE INITIAL INTENSITY REMAINS ASSESSED AT 35 KNOTS BASED
ON DVORAK CURRENT INTENSITY ESTIMATES OF 35 KNOTS FROM PGTW AND
RJTD. UPPER-LEVEL ANALYSIS INDICATES THAT THE SYSTEM IS LOCATED
UNDER AN UPPER LOW, WHICH IS HINDERING CONVECTIVE DEVELOPMENT. TS
13W IS TRACKING ALONG THE SOUTHWEST PERIPHERY OF A LOW- TO
MID-LEVEL SUBTROPICAL RIDGE (STR) POSITIONED TO THE NORTHEAST.
3. FORECAST REASONING.
A. NO CHANGE TO THE FORECAST TRACK PHILOSOPHY SINCE THE PREVIOUS
PROGNOSTIC REASONING MESSAGE.
B. TS 13W IS FORECAST TO CONTINUE TRACKING NORTH-NORTHWESTWARD
ALONG THE WESTERN PERIPHERY OF THE STR THROUGH THE FORECAST PERIOD.
NEAR TAU 48, THE SYSTEM WILL TRACK WITHIN THE LEADING PERIPHERY OF A
SHARP SHORTWAVE TROUGH AND WILL BEGIN A GRADUAL EXTRA-TROPICAL
TRANSITION (ETT). AFTER TAU 48, TS 13W WILL TRACK OVER COOLER SST
(24 TO 25C) AND WILL GAIN WEAK FRONTAL CHARACTERISTICS, COMPLETING
ETT BY TAU 72. DYNAMIC GUIDANCE IS IN TIGHT AGREEMENT, THEREFORE,
THERE IS HIGH CONFIDENCE IN THE JTWC FORECAST TRACK.//
NNNN

[euro6208]

WDPN33 PGTW 031500
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 13W (NALGAE)
WARNING NR 11//
RMKS//
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
TROPICAL STORM (TS) 13W (NALGAE), LOCATED APPROXIMATELY 519 NM
NORTH-NORTHWEST OF WAKE ISLAND, HAS TRACKED NORTHWESTWARD AT 07 KNOTS
OVER THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED SATELLITE
IMAGERY AND A 031111Z GPM IMAGE DEPICT FORMATIVE CONVECTIVE BANDING
OVER THE EASTERN SEMI-CIRCLE OF THE BROAD LOW-LEVEL CIRCULATION
CENTER (LLCC). A 030955Z ASCAT IMAGE SHOWS 35 TO 40 KNOT WINDS OVER
THE NORTHEAST QUADRANT OF THE CIRCULATION WITH 30 TO 35 KNOT WINDS
ELSEWHERE. THIS ASCAT IMAGE SHOWS A WELL-DEFINED CENTER AND SUPPORTS
THE INITIAL POSITION AND INITIAL INTENSITY ASSESSMENT OF 40 KNOTS
WITH GOOD CONFIDENCE. UPPER-LEVEL ANALYSIS INDICATES THAT THE SYSTEM
IS LOCATED UNDER AN UPPER LOW, WHICH IS HINDERING CONVECTIVE
DEVELOPMENT. TS 13W IS TRACKING ALONG THE SOUTHWEST PERIPHERY OF A
LOW- TO MID-LEVEL SUBTROPICAL RIDGE (STR) POSITIONED TO THE
NORTHEAST.
3. FORECAST REASONING.
A. NO CHANGE TO THE FORECAST TRACK PHILOSOPHY SINCE THE PREVIOUS
PROGNOSTIC REASONING MESSAGE. THE 34-KNOT WIND RADII HAVE BEEN
ADJUSTED SIGNIFICANTLY LARGER BASED ON A DETAILED ANALYSIS OF A
RECENT ASCAT IMAGE.
B. TS 13W IS FORECAST TO CONTINUE TRACKING NORTH-NORTHWESTWARD
ALONG THE WESTERN PERIPHERY OF THE STR THROUGH THE FORECAST PERIOD.
NEAR TAU 48, THE SYSTEM WILL TRACK WITHIN THE LEADING PERIPHERY OF A
SHARP SHORTWAVE TROUGH AND WILL BEGIN A GRADUAL EXTRA-TROPICAL
TRANSITION (ETT). AFTER TAU 48, TS 13W WILL TRACK OVER COOLER SST
(24 TO 25C) AND WILL GAIN WEAK FRONTAL CHARACTERISTICS, COMPLETING
ETT BY TAU 72. DYNAMIC GUIDANCE IS IN TIGHT AGREEMENT, THEREFORE,
THERE IS HIGH CONFIDENCE IN THE JTWC FORECAST TRACK.//
NNNN

[euro6208]

WDPN33 PGTW 040900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 13W (NALGAE)
WARNING NR 14//
RMKS//
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
TROPICAL STORM 13W (NALGAE), LOCATED APPROXIMATELY 536 NM NORTHEAST
OF MINAMI TORI SHIMA, HAS TRACKED NORTH-NORTHWESTWARD AT 06 KNOTS
OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY
DEPICTS A PARTIALLY EXPOSED LOW LEVEL CIRCULATION CENTER WITH
BANDING CONVECTION ISOLATED TO THE NORTHERN PERIPHERY. THERE IS HIGH
CONFIDENCE IN THE INITIAL POSITION BASED ON THE EXPOSED LOW LEVEL
AND RECENT SATELLITE FIXES. THE INITIAL
INTENSITY OF 40 KNOTS IS BASED ON A PREVIOUS 032222Z METOP-B ASCAT
IMAGE SHOWING 40 KNOT WIND BARBS ON THE NORTHERN PERIPHERY, WHILE
SUBJECTIVE DVORAK ESTIMATES HAVE BEEN CONSISTENTLY LOW WITH AGENCIES
REPORTING T2.0 TO 2.5 (30 TO 35 KNOTS). UPPER-LEVEL ANALYSIS
IMPROVING POLEWARD OUTFLOW WITH RESTRICTED EQUATORWARD OUTFLOW DUE
TO A WEAK UPPER-LEVEL TROUGH TO THE SOUTHWEST. OTHERWISE, VERTICAL
WIND SHEAR IS LOW AND SSTS MODERATELY SUPPORT DEVELOPMENT AT 27 TO
28 CELSIUS. TS 13W IS TRACKING ALONG THE SOUTHWEST PERIPHERY OF A
LOW TO MID-LEVEL SUBTROPICAL RIDGE (STR) POSITIONED
TO THE NORTHEAST.
3. FORECAST REASONING.
A. NO CHANGE TO THE FORECAST TRACK PHILOSOPHY SINCE THE PREVIOUS
PROGNOSTIC REASONING MESSAGE.
B. TS NALGAE IS FORECAST TO CONTINUE TRACKING NORTH-NORTHWESTWARD
ALONG THE WESTERN PERIPHERY OF THE STR THROUGH THE FORECAST PERIOD.
NEAR TAU 36, THE SYSTEM WILL TRACK WITHIN THE LEADING PERIPHERY OF A
SHARP SHORTWAVE TROUGH AND WILL BEGIN EXTRA-TROPICAL TRANSITION
(ETT). AFTER TAU 24, TS 13W WILL TRACK OVER COOLER SST (24 TO 25C)
AND WILL GAIN WEAK FRONTAL CHARACTERISTICS, COMPLETING ETT BY TAU 48.
DYNAMIC MODEL GUIDANCE IS IN VERY GOOD AGREEMENT, LENDING HIGH
CONFIDENCE IN THE JTWC FORECAST TRACK.//
NNNN

[euro6208]

WDPN33 PGTW 050900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 13W (NALGAE) WARNING NR
18//
RMKS//
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
TROPICAL DEPRESSION 13W (NALGAE), LOCATED APPROXIMATELY 739 NM
NORTH-NORTHEAST OF MINAMI TORI SHIMA, HAS TRACKED NORTHWARD AT 19
KNOTS OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE
IMAGERY SHOWS WEAK CONVECTIVE BANDING SHEARED TO THE NORTHWEST OF A
BROAD LOW LEVEL CIRCULATION CENTER (LLCC). THE INITIAL POSITION IS
BASED ON ANIMATED VISIBLE IMAGERY AND A 050328Z SSMI 85GHZ MICROWAVE
IMAGE WITH HIGH CONFIDENCE. THE INITIAL INTENSITY OF 30 KNOTS IS
BASED ON MULTI AGENCY DVORAK ESTIMATES OF T2.0 FROM PGTW AND RJTD.
ENVIRONMENTAL ANALYSIS SHOWS THE SYSTEM IS IN AN UNFAVORABLE AREA
WITH STRONG POLEWARD OUTFLOW BEGIN OFFSET BY MODERATE (15-20 KNOTS)
VERTICAL WIND SHEAR (VWS) AND LOW SEA SURFACE TEMPERATURES (25
CELSIUS). TD NALGAE IS CURRENTLY TRACKING NORTH-NORTHWEST ALONG THE
WESTERN PERIPHERY OF A SUBTROPICAL RIDGE LOCATED TO THE NORTHEAST OF
THE SYSTEM.
3. FORECAST REASONING.
A. NO CHANGE TO THE FORECAST TRACK PHILOSOPHY SINCE THE PREVIOUS
PROGNOSTIC REASONING MESSAGE.
B. TD NALGAE IS FORECAST TO CONTINUE TRACKING NORTH-NORTHWEST FOR
THE DURATION OF THE FORECAST PERIOD ALONG THE WESTERN PERIPHERY OF A
SUB TROPICAL STEERING RIDGE LOCATED TO THE NORTHEAST. THE SYSTEM
WILL CONTINUE TO TRACK THROUGH COOL SEA SURFACE TEMPERATURES AS IT
UNDERGOES EXTRA-TROPICAL TRANSITION. BY THE END OF THE FORECAST
PERIOD THE SYSTEM WILL BE A COLD-CORE LOW. DYNAMIC MODEL GUIDANCE
REMAINS IN STRONG AGREEMENT LENDING HIGH CONFIDENCE IN THE JTWC
FORECAST TRACK.//
NNNN

[euro6208]

WTPN33 PGTW 051500
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE WARNING//
RMKS/
1. TROPICAL DEPRESSION 13W (NALGAE) WARNING NR 019
02 ACTIVE TROPICAL CYCLONES IN NORTHWESTPAC
MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
WIND RADII VALID OVER OPEN WATER ONLY
---
WARNING POSITION:
051200Z --- NEAR 36.0N 161.4E
MOVEMENT PAST SIX HOURS - 340 DEGREES AT 18 KTS
POSITION ACCURATE TO WITHIN 025 NM
POSITION BASED ON CENTER LOCATED BY SATELLITE
PRESENT WIND DISTRIBUTION:
MAX SUSTAINED WINDS - 025 KT, GUSTS 035 KT
WIND RADII VALID OVER OPEN WATER ONLY
REPEAT POSIT: 36.0N 161.4E
---
FORECASTS:
12 HRS, VALID AT:
060000Z --- 39.2N 159.5E
MAX SUSTAINED WINDS - 025 KT, GUSTS 035 KT
WIND RADII VALID OVER OPEN WATER ONLY
BECOMING EXTRATROPICAL
VECTOR TO 24 HR POSIT: 335 DEG/ 15 KTS
---
24 HRS, VALID AT:
061200Z --- 42.0N 157.8E
MAX SUSTAINED WINDS - 020 KT, GUSTS 030 KT
WIND RADII VALID OVER OPEN WATER ONLY
EXTRATROPICAL
---
REMARKS:
051500Z POSITION NEAR 36.8N 160.9E.
TROPICAL DEPRESSION 13W (NALGAE), LOCATED APPROXIMATELY 805 NM
NORTH-NORTHEAST OF MINAMI TORI SHIMA, HAS TRACKED NORTH-
NORTHWESTWARD AT 18 KNOTS OVER THE PAST SIX HOURS.
THIS IS THE FINAL WARNING ON THIS SYSTEM BY THE JOINT TYPHOON
WRNCEN PEARL HARBOR HI. THE SYSTEM WILL BE CLOSELY MONITORED FOR
SIGNS OF REGENERATION. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 051200Z
IS 10 FEET. REFER TO TYPHOON 07W (NORU) WARNINGS (WTPN31 PGTW)
FOR SIX-HOURLY UPDATES.
//
NNNN

[euro6208]

Only 40-45 knots peak from JTWC and JMA however due to their reliance on dvorak, it seems like Nalgae was underestimated. I've seen hurricanes in the atlantic worser.

ASCAT actually showed 55 to 60 knots.

[NotoSans]

JMA actually bumped up the intensity to 45 kt before declaring Nalgae as an extratropical system, even though their Dvorak CI number was down to 2.0 at that time (which would normally yield an intensity of 35 kt on the Koba scale). Although their intensity estimate still looks a bit low to me, I don't think JMA is heavily dependent on Dvorak analysis in this case.