WPAC: SONCA - Tropical Depression

[SuperMarioBros99thx]

Likely to be Kulap first. I am not so sure, but if it did i wouldn't be surprised.

[dexterlabio]

Euro got this first fwiw

[NotoSans]

JMA now expects it to become a TS within 24 hours. The Euro has also trended slightly stronger for this system.

[doomhaMwx]

Likely to be Kulap first. I am not so sure, but if it did i wouldn't be surprised.

Nahh, JMA has just assigned the name Kulap to 97W...
The next name's "Roke"...

[Sciencerocks]

Looks good. Likely tropical storm within the next 6-12 hours and afterwards this has a slight chance of becoming a typhoon.

[euro6208]

WDPN32 PGTW 210900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL DEPRESSION 08W (EIGHT)
WARNING NR 02/
RMKS//
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
TROPICAL DEPRESSION (TD) 08W (EIGHT), LOCATED APPROXIMATELY 271 NM
SOUTH OF HONG KONG, HAS TRACKED WEST-NORTHWESTWARD AT 11 KNOTS OVER
THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY DEPICTS
A CONSOLIDATING, COMPACT LOW-LEVEL CIRCULATION CENTER (LLCC) WITH
DEEP CONVECTIVE BANDING WRAPPING TIGHTLY INTO THE CENTER. A 210751Z
GPM MICROWAVE IMAGE SHOWS EXPOSED SHALLOW BANDING, JUST EAST OF THE
CORE CONVECTION, WRAPPING INTO THE LLCC. UPPER-LEVEL ANALYSIS SHOWS
A MARGINALLY-FAVORABLE ENVIRONMENT WITH A SLIGHT IMPROVEMENT IN
POLEWARD OUTFLOW ASSOCIATED WITH A TUTT CELL OVER TAIWAN. A 210137Z
ASCAT BULLS-EYE 25-KM IMAGE SHOWS 25 TO 30 KNOT WINDS AND SUPPORTS
THE CURRENT INTENSITY ASSESSMENT OF 30 KNOTS. TD 08W IS TRACKING
NORTHWESTWARD UNDER THE STEERING INFLUENCE OF THE LOW-LEVEL
SUBTROPICAL RIDGE (STR) POSITIONED TO THE NORTH.
3. FORECAST REASONING.
A. NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS
PROGNOSTIC REASONING MESSAGE.
B. TD 08W IS FORECAST TRACK WEST-NORTHWESTWARD UNDER THE STEERING
INFLUENCE OF THE EAST-WEST ORIENTED STR TO THE NORTH. THE SYSTEM
WILL TRACK OVER HAINAN ISLAND, MAKING LANDFALL NEAR TAU 30, THEN
CROSS OVER THE GULF OF TONKIN FOR A BRIEF PERIOD OF TIME BEFORE
MAKING ITS SECOND LANDFALL OVER NORTHERN VIETNAM NEAR 72. DYNAMIC
GUIDANCE IS VERY LIMITED DUE TO THE POOR INITIALIZATION OF THE
AVAILABLE GLOBAL MODELS, THEREFORE, THERE IS LOW CONFIDENCE
IN THE JTWC FORECAST TRACK. TD 08W IS FORECAST TO INTENSIFY STEADILY
TO A PEAK INTENSITY OF 50 KNOTS, HOWEVER, THERE IS CONSIDERABLE
UNCERTAINTY IN THE PEAK INTENSITY DUE TO THE MODEL'S POOR
INITIALIZATION AND THE SMALL SYSTEM SIZE (HISTORICALLY FAVORABLE FOR
RAPID INTENSIFICATION).
C. IN THE EXTENDED FORECAST PERIOD, TD 08W WILL DISSIPATE OVER
VIETNAM BY TAU 96.//
NNNN

[euro6208]

I'm praying this doesn't get the name Roke which was submitted by the U.S territory of Guam which is a Chamorro man's name to keep it around longer but that doesn't look likely.

[Sciencerocks]

TPN32 PGTW 212100
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE WARNING//
RMKS/
1. TROPICAL DEPRESSION 08W (EIGHT) WARNING NR 004
04 ACTIVE TROPICAL CYCLONES IN NORTHWESTPAC
MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
WIND RADII VALID OVER OPEN WATER ONLY
---
WARNING POSITION:
211800Z --- NEAR 18.1N 112.6E
MOVEMENT PAST SIX HOURS - 280 DEGREES AT 05 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: 18.1N 112.6E
---
FORECASTS:
12 HRS, VALID AT:
220600Z --- 18.7N 111.5E
MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT
WIND RADII VALID OVER OPEN WATER ONLY
VECTOR TO 24 HR POSIT: 315 DEG/ 02 KTS
---
24 HRS, VALID AT:
221800Z --- 19.0N 111.2E
MAX SUSTAINED WINDS - 025 KT, GUSTS 035 KT
WIND RADII VALID OVER OPEN WATER ONLY
VECTOR TO 36 HR POSIT: 295 DEG/ 04 KTS
---
36 HRS, VALID AT:
230600Z --- 19.3N 110.5E
MAX SUSTAINED WINDS - 025 KT, GUSTS 035 KT
WIND RADII VALID OVER OPEN WATER ONLY
DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER LAND
VECTOR TO 48 HR POSIT: 280 DEG/ 07 KTS
---
EXTENDED OUTLOOK:
48 HRS, VALID AT:
231800Z --- 19.5N 109.1E
MAX SUSTAINED WINDS - 020 KT, GUSTS 030 KT
WIND RADII VALID OVER OPEN WATER ONLY
DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER LAND
---
REMARKS:
212100Z POSITION NEAR 18.3N 112.3E.
TROPICAL DEPRESSION 08W (EIGHT), LOCATED APPROXIMATELY 130 NM
EAST-SOUTHEAST OF HAINAN, CHINA, HAS TRACKED WESTWARD AT 05 KNOTS
OVER THE PAST SIX HOURS. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 211800Z
IS 10 FEET. NEXT WARNINGS AT 220300Z, 220900Z, 221500Z AND 222100Z.
REFER TO TROPICAL STORM 07W (NORU) WARNINGS (WTPN31 PGTW) FOR SIX-
HOURLY UPDATES. REFER TO TROPICAL STORM 09W (KULAP) WARNINGS (WTPN33
PGTW) FOR SIX-HOURLY UPDATES. REFER TO TROPICAL CYCLONE 10W (TEN)
WARNINGS (WTPN34 PGTW) FOR SIX-HOURLY UPDATES.//
NNNN

[Sciencerocks]

WDPN32 PGTW 212100
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL DEPRESSION 08W (EIGHT)
WARNING NR 04/
RMKS//
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
TROPICAL DEPRESSION (TD) 08W (EIGHT), LOCATED APPROXIMATELY 130 NM
EAST-SOUTHEAST OF HAINAN, CHINA, HAS TRACKED WESTWARD AT 05 KNOTS
OVER THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED SATELLITE (EIR)
IMAGERY DEPICTS AN OVERALL WEAKENING TREND WITH ISOLATED DEEP
CONVECTION FLARING OVER THE COMPACT LOW-LEVEL CIRCULATION. UPPER-
LEVEL ANALYSIS INDICATES A MARGINALLY-FAVORABLE ENVIRONMENT WITH
MODERATE POLEWARD OUTFLOW. THE INITIAL POSITION IS BASED ON THE EIR
LOOP WITH LOW CONFIDENCE. THE INITIAL INTENSITY IS ASSESSED AT 25
KNOTS BASED ON DVORAK ESTIMATES FROM PGTW AND RJTD. TD 08W IS
TRACKING WEST-NORTHWESTWARD UNDER THE STEERING INFLUENCE OF THE LOW-
LEVEL SUBTROPICAL RIDGE (STR) TO THE NORTHEAST.
3. FORECAST REASONING.
A. NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS
PROGNOSTIC REASONING MESSAGE.
B. TD 08W IS FORECAST TO CONTINUE TRACKING GENERALLY WEST-
NORTHWESTWARD UNDER THE STEERING INFLUENCE OF THE STR, MAKING
LANDFALL OVER HAINAN AFTER TAU 24. THE SYSTEM WILL INTENSIFY
SLIGHTLY OVER THE NEXT 12 HOURS, PEAKING AT 30 KNOTS BEFORE
LANDFALL. AFTERWARDS, INTERACTION WITH THE RUGGED TERRAIN OF HAINAN
WILL CAUSE RAPID DECAY AND EVENTUAL DISSIPATION BY TAU 48. DYNAMIC
GUIDANCE IS NOW SIGNIFICANTLY SPREAD OUT AFTER TAU 24. IN VIEW OF
THIS, PLUS GIVEN THE ERRATIC MOTION OF A DECAYING SYSTEM, THERE IS
LOW CONFIDENCE IN THE JTWC FORECAST TRACK.//
NNNN

[1900hurricane]

Latest radar for 08W:

[mrbagyo]

[Sciencerocks]

Probably more like 35 knots

WTPN32 PGTW 220300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE WARNING//
RMKS/
1. TROPICAL DEPRESSION 08W (EIGHT) WARNING NR 005
04 ACTIVE TROPICAL CYCLONES IN NORTHWESTPAC
MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
WIND RADII VALID OVER OPEN WATER ONLY
---
WARNING POSITION:
220000Z --- NEAR 18.2N 112.2E
MOVEMENT PAST SIX HOURS - 285 DEGREES AT 04 KTS
POSITION ACCURATE TO WITHIN 020 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: 18.2N 112.2E
---
FORECASTS:
12 HRS, VALID AT:
221200Z --- 18.5N 111.7E
MAX SUSTAINED WINDS - 025 KT, GUSTS 035 KT
WIND RADII VALID OVER OPEN WATER ONLY
VECTOR TO 24 HR POSIT: 325 DEG/ 03 KTS
---
24 HRS, VALID AT:
230000Z --- 19.0N 111.3E
MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT
WIND RADII VALID OVER OPEN WATER ONLY
VECTOR TO 36 HR POSIT: 290 DEG/ 04 KTS
---
36 HRS, VALID AT:
231200Z --- 19.3N 110.5E
MAX SUSTAINED WINDS - 025 KT, GUSTS 035 KT
WIND RADII VALID OVER OPEN WATER ONLY
DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER LAND
VECTOR TO 48 HR POSIT: 275 DEG/ 05 KTS
---
EXTENDED OUTLOOK:
48 HRS, VALID AT:
240000Z --- 19.4N 109.4E
MAX SUSTAINED WINDS - 020 KT, GUSTS 030 KT
WIND RADII VALID OVER OPEN WATER ONLY
DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER LAND
---
REMARKS:
220300Z POSITION NEAR 18.3N 112.1E.
TROPICAL DEPRESSION 08W (EIGHT), LOCATED APPROXIMATELY 107 NM
EAST-SOUTHEAST OF HAINAN, CHINA, HAS TRACKED WEST-
NORTHWESTWARD AT 04 KNOTS OVER THE PAST SIX HOURS.
MAXIMUM SIGNIFICANT WAVE HEIGHT AT 220000Z IS 10 FEET. NEXT
WARNINGS AT 220900Z, 221500Z, 222100Z AND 230300Z. REFER TO TROPICAL
STORM 07W (NORU) WARNINGS (WTPN31 PGTW) FOR SIX-HOURLY UPDATES. REFER
TO TROPICAL STORM 09W (KULAP) WARNINGS (WTPN33 PGTW) FOR SIX-HOURLY
UPDATES. REFER TO TROPICAL DEPRESSION 10W (TEN) WARNINGS (WTPN34
PGTW) FOR SIX-HOURLY UPDATES.
//
NNNN

[euro6208]

WDPN32 PGTW 220300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL DEPRESSION 08W (EIGHT)
WARNING NR 05/
RMKS//
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
TROPICAL DEPRESSION (TD) 08W (EIGHT), LOCATED APPROXIMATELY 107 NM
EAST-SOUTHEAST OF HAINAN, CHINA, HAS TRACKED WEST-NORTHWESTWARD AT
04 KNOTS OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE
IMAGERY SHOWS DIURNAL FLARING CONVECTION OVER THE COMPACT LOW-LEVEL
CIRCULATION (LLC). UPPER-LEVEL ANALYSIS INDICATES A MARGINALLY-
FAVORABLE ENVIRONMENT WITH LIGHT NORTHERLY VERTICAL WINDSHEAR OFFSET
BY MODERATE POLEWARD OUTFLOW. THE INITIAL POSITION IS BASED ON A LOW
REFLECTIVITY CIRCULATION FEATURE IN THE 212258Z 37GHZ SSMIS PASS
WITH FAIR CONFIDENCE. THE SSMIS IMAGE ALSO HIGHLIGHTS THE CENTRAL
CONVECTION DISPLACED SOUTHWARD OF THE LLC. THE INITIAL INTENSITY OF
25 KNOTS IS HELD SLIGHTLY LOWER THAN DVORAK ESTIMATES TO REFLECT THE
SHEARED AND WEAK CONVECTION. TD 08W IS TRACKING WEST-NORTHWESTWARD
UNDER THE STEERING INFLUENCE OF THE LOW-LEVEL SUBTROPICAL RIDGE
(STR) TO THE NORTHEAST.
3. FORECAST REASONING.
A. NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS
PROGNOSTIC REASONING MESSAGE.
B. TD 08W IS FORECAST TO CONTINUE TRACKING GENERALLY WEST-
NORTHWESTWARD UNDER THE STEERING INFLUENCE OF THE STR, MAKING
LANDFALL OVER HAINAN AFTER TAU 24. THE SYSTEM WILL INTENSIFY
SLIGHTLY OVER THE NEXT 12 HOURS, PEAKING AT 30 KNOTS BEFORE
LANDFALL. AFTERWARDS, INTERACTION WITH THE RUGGED TERRAIN OF HAINAN
WILL CAUSE RAPID DECAY AND EVENTUAL DISSIPATION BY TAU 36. DYNAMIC
GUIDANCE IS SIGNIFICANTLY SPREAD. IN VIEW OF THIS, PLUS GIVEN THE
ERRATIC MOTION OF A DECAYING SYSTEM, THERE IS LOW CONFIDENCE IN THE
JTWC FORECAST TRACK.//
NNNN

[euro6208]

Another missed TS that's been one for quite some time now.

[euro6208]

So this will be named Sonca soon...

[NotoSans]

I would say this system becomes a TS at around 00 to 06Z. Previous ASCAT passes don't provide enough evidence for a TS upgrade even taking in account the under-sampling.

[euro6208]

WDPN32 PGTW 220900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL DEPRESSION 08W (EIGHT)
WARNING NR 06/
RMKS//
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
TROPICAL DEPRESSION (TD) 08W (EIGHT), LOCATED APPROXIMATELY 238 NM
EAST-NORTHEAST OF DA NANG, VIETNAM, HAS TRACKED WESTWARD AT 06
KNOTS OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE
IMAGERY DEPICTS IMPROVED CONVECTIVE ORGANIZATION WITH CURVED
CONVECTIVE BANDING WRAPPING INTO A PARTIALLY-EXPOSED LOW-LEVEL
CIRCULATION CENTER (LLCC), WHICH SUPPORTS THE CURRENT POSITION WITH
GOOD CONFIDENCE. A 220201Z METOP-A 89GHZ IMAGE SHOWS A COMPACT LLCC
WITH DEEP CONVECTIVE BANDING OVER THE WEST AND SOUTH QUADRANTS AND
SHALLOW BANDING ELSEWHERE. UPPER-LEVEL ANALYSIS INDICATES A
MARGINALLY-FAVORABLE ENVIRONMENT WITH LOW TO MODERATE VERTICAL WIND
SHEAR (15-20 KNOTS) OFFSET BY GOOD EQUATORWARD OUTFLOW AND WEAK
POLEWARD OUTFLOW. THE CURRENT INTENSITY IS ASSESSED AT 30 KNOTS
BASED ON DVORAK ESTIMATES OF T2.0 (30 KNOTS) FROM PGTW AND RJTD. TD
08W IS TRACKING SLOWLY WESTWARD UNDER THE STEERING INFLUENCE OF THE
LOW-LEVEL SUBTROPICAL RIDGE (STR) POSITIONED TO THE NORTH.
3. FORECAST REASONING.
A. NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS
PROGNOSTIC REASONING MESSAGE.
B. TD 08W IS FORECAST TO CONTINUE TRACKING GENERALLY WEST-
NORTHWESTWARD UNDER THE STEERING INFLUENCE OF THE STR, MAKING
LANDFALL OVER HAINAN AFTER TAU 24. THE SYSTEM WILL INTENSIFY
SLIGHTLY OVER THE NEXT 12 HOURS, PEAKING AT 35 KNOTS BEFORE
LANDFALL. AFTERWARDS, INTERACTION WITH THE RUGGED TERRAIN OF HAINAN
WILL CAUSE RAPID DECAY AND EVENTUAL DISSIPATION BY TAU 72. DYNAMIC
GUIDANCE IS IN POOR AGREEMENT, THEREFORE, THERE IS LOW CONFIDENCE IN
THE JTWC FORECAST TRACK.//
NNNN

[doomhaMwx]

Tropical Depression 08W and Tropical Storm Roke Approaching Southern China
NASA MODIS Imagery
07-22-2017 05:55 UTC

[euro6208]

Looks like a moderate TS already. Small and compact and more powerful than what JTWC and JMA thinks. It's there.

[Sciencerocks]

Looks about 45 knots to me. I compare all storms to Atlantic storms that had recon so I guess I have different standards from the JMA. Looks like Tropical storm Macro of 2008 in the southern BOC...

http://www.ssd.noaa.gov/PS/TROP/floater ... imated.gif