WPAC: Mun - Tropical Storm

[Nancy Smar]

96W.INVEST.15kts.1010mb.16N.115E

[Hayabusa]

LOW PRESSURE AREA 1002 HPA NEAR 19N 114E ALMOST STATIONARY.

Well it was already assigned as an LPA by JMA even before 96W was assigned.

[Nancy Smar]

WTPQ20 RJTD 010600
RSMC TROPICAL CYCLONE ADVISORY
NAME TD
ANALYSIS
PSTN 010600UTC 18.4N 114.2E POOR
MOVE WNW SLOWLY
PRES 998HPA
MXWD 030KT
GUST 045KT
FORECAST
24HF 020600UTC 18.7N 111.9E 80NM 70%
MOVE W SLOWLY
PRES 992HPA
MXWD 035KT
GUST 050KT =

[euro6208]

AN AREA OF CONVECTION (INVEST 96W) HAS PERSISTED NEAR
16.4N 114.8E, APPROXIMATELY 350 NM SOUTH OF HONG KONG. ANIMATED
MULTISPECTRAL SATELLITE IMAGERY SHOWS A BROAD AREA OF TURNING WITH
SCATTERED CONVECTION LOCATED IN THE SOUTHERN SEMI-CIRCLE. A 010213Z
METOP-A ASCAT IMAGE SHOWS A BROAD AREA OF TURNING WHICH HAS NOT YET
CONSOLIDATED. UPPER LEVEL ANALYSIS SHOWS FAVORABLE TO NEUTRAL
VERTICAL WIND SHEAR (15 TO 20 KNOTS). THERE IS NO POLEWARD OUTFLOW
CHANNEL, BUT THERE IS A DEVELOPING EQUATORWARD OUTFLOW CHANNEL. SEA
SURFACE TEMPERATURES ARE FAVORABLE FOR DEVELOPMENT, NEAR 30 DEGREES
CELSIUS. NUMERICAL MODEL GUIDANCE SHOWS INVEST 96W TRACKING WESTWARD
AND CONSOLIDATING OVER THE NEXT FEW DAYS AS ENVIRONMENTAL CONDITIONS
IMPROVE. MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 10 TO 15
KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1001 MB.
THE POTENTIAL FOR THE DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE
WITHIN THE NEXT 24 HOURS IS LOW.

[euro6208]

GFS and EURO has some modest strengthening before making landfall over Northern Hainan Island.

[wxman57]

JMA has called this mess a tropical depression. They are issuing advisories.

[euro6208]

JMA has called this mess a tropical depression. They are issuing advisories.

Not surprising. Don't they upgrade every LPA into a TD? Maybe if this were the Atlantic, I might believe.

[wxman57]

JMA has called this mess a tropical depression. They are issuing advisories.

Not surprising. Don't they upgrade every LPA into a TD? Maybe if this were the Atlantic, I might believe.

They call every low in the tropics a "TD", but they only issue advisories if the low is predicted to become a TS within 12 hrs (which I think is unlikely in this case).

[Nancy Smar]

(1) THE AREA OF CONVECTION (INVEST 96W) PREVIOUSLY LOCATED
NEAR 16.4N 114.8E, IS NOW LOCATED NEAR 18.2N 114.7E, APPROXIMATELY
247 NM SOUTH OF HONG KONG. ANIMATED ENHANCED INFRARED SATELLITE
IMAGERY SHOWS A BROAD AREA OF TURNING WITH SCATTERED CONVECTION
LOCATED IN THE SOUTHERN SEMI-CIRCLE. A 011054Z SSMIS 37GHZ MICROWAVE
IMAGE CONFIRMS THE BROAD NATURE OF THE CIRCULATION AND THAT THE
CONVECTION REMAINS CONFINED TO THE SOUTHERN SEMI-CIRCLE. UPPER LEVEL
ANALYSIS SHOWS FAVORABLE TO NEUTRAL VERTICAL WIND SHEAR (15 TO 20
KNOTS). THERE IS NO POLEWARD OUTFLOW CHANNEL BUT THERE IS A
DEVELOPING EQUATORWARD OUTFLOW CHANNEL. SEA SURFACE TEMPERATURES ARE
FAVORABLE FOR DEVELOPMENT, NEAR 30 DEGREES CELSIUS. NUMERICAL MODEL
GUIDANCE CONTINUES TO SHOW INVEST 96W TRACKING WESTWARD AND
CONSOLIDATING OVER THE NEXT FEW DAYS AS ENVIRONMENTAL CONDITIONS
IMPROVE. MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 15 TO 20
KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1001 MB.
THE POTENTIAL FOR THE DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE
WITHIN THE NEXT 24 HOURS IS UPGRADED TO MEDIUM.

[Nancy Smar]

JMA has called this mess a tropical depression. They are issuing advisories.

Not surprising. Don't they upgrade every LPA into a TD? Maybe if this were the Atlantic, I might believe.

They call every low in the tropics a "TD", but they only issue advisories if the low is predicted to become a TS within 12 hrs (which I think is unlikely in this case).

No，it means that the low is predicted to become a Tropical Storm within 24hrs(sometimes 48hrs).

[euro6208]

(1) THE AREA OF CONVECTION (INVEST 96W) PREVIOUSLY LOCATED
NEAR 16.4N 114.8E, IS NOW LOCATED NEAR 18.2N 114.7E, APPROXIMATELY
247 NM SOUTH OF HONG KONG. ANIMATED ENHANCED INFRARED SATELLITE
IMAGERY SHOWS A BROAD AREA OF TURNING WITH SCATTERED CONVECTION
LOCATED IN THE SOUTHERN SEMI-CIRCLE. A 011054Z SSMIS 37GHZ MICROWAVE
IMAGE CONFIRMS THE BROAD NATURE OF THE CIRCULATION AND THAT THE
CONVECTION REMAINS CONFINED TO THE SOUTHERN SEMI-CIRCLE. UPPER LEVEL
ANALYSIS SHOWS FAVORABLE TO NEUTRAL VERTICAL WIND SHEAR (15 TO 20
KNOTS). THERE IS NO POLEWARD OUTFLOW CHANNEL BUT THERE IS A
DEVELOPING EQUATORWARD OUTFLOW CHANNEL. SEA SURFACE TEMPERATURES ARE
FAVORABLE FOR DEVELOPMENT, NEAR 30 DEGREES CELSIUS. NUMERICAL MODEL
GUIDANCE CONTINUES TO SHOW INVEST 96W TRACKING WESTWARD AND
CONSOLIDATING OVER THE NEXT FEW DAYS AS ENVIRONMENTAL CONDITIONS
IMPROVE. MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 15 TO 20
KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1001 MB.
THE POTENTIAL FOR THE DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE
WITHIN THE NEXT 24 HOURS IS UPGRADED TO MEDIUM.

Nice...

As an RSMC, Why can't JMA even provide something like this so we can't be guessing all the time? Or.....?

I see NHC doing it in the WHEM too...

[Grifforzer]

WTPQ30 RJTD 011200
RSMC TROPICAL CYCLONE PROGNOSTIC REASONING
REASONING NO. 2 FOR TD LOCATED AT 17.7N 113.1E

1.GENERAL COMMENTS
A TD IS LOCATED AT 17.7N, 113.1E. INFORMATION ON THE CURRENT POSITION IS BASED ON ANIMATED MSI AND SURFACE OBSERVATIONS. POSITIONAL ACCURACY IS POOR BECAUSE THE CSC IS OBSCURE. THE SYSTEM IS IN A FAVORABLE ENVIRONMENT FOR DEVELOPMENT UNDER THE INFLUENCE OF HIGH SSTS, HIGH TCHP AND WEAK VWS. THIS HAS CAUSED THE SYSTEM TO DEVELOP OVER THE LAST SIX HOURS. HOWEVER, THE INFLUENCE OF DRY AIR IS UNFAVORABLE FOR SYSTEM DEVELOPMENT. INFORMATION ON CURRENT INTENSITY IS BASED ON SURFACE OBSERVATIONS.

2.SYNOPTIC SITUATION
THE SYSTEM IS MOVING WESTWARD DUE TO WEAK STEERING FLOW. ANIMATED MSI SHOWS CB CLUSTERS ARE SCATTERED AROUND THE CSC. WATER VAPOR IMAGERY SHOWS DRY AIR AROUND THE SYSTEM. DMSP-F18/SSMIS 89 GHZ MICROWAVE IMAGERY SHOWS THE SYSTEM HAS ACTIVE CONVECTIVE CLOUD CLUSTERS AROUND THE CSC.

3.TRACK FORECAST
THE SYSTEM WILL MOVE WESTWARD DUE TO WEAK STEERING FLOW UNTIL FT24. THE JMA TRACK FORECAST IS BASED ON GSM PREDICTIONS, AND REFERENCE TO OTHER NWP MODELS. JMA TRACK FORECAST CONFIDENCE IS FAIR BECAUSE ALL NUMERICAL MODELS ARE IN CLOSE AGREEMENT.

4.INTENSITY FORECAST
THE SYSTEM WILL DEVELOP UNTIL FT24 DUE TO THE INFLUENCE OF INTERACTION WITH HIGH SSTS, HIGH TCHP AND WEAK VWS. THE SYSTEM WILL BE UPGRADED TO TS INTENSITY BY FT24. THE JMA INTENSITY FORECAST IS BASED ON A CONSENSUS OF GUIDANCE DATA INCLUDING GSM.

[Hayabusa]

Could this finally become the first decent TC since Wutip? Sorry I can't consider 94W (Sepat), 95W (04W) as a decent TC, even if 94W was considered a TS I just can't see it as a TS nor 95W

WTPN21 PGTW 012100
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE FORMATION ALERT//
RMKS/
1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN
170 NM EITHER SIDE OF A LINE FROM 17.4N 113.8E TO 20.9N 107.3E
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 18 TO 23 KNOTS. METSAT
IMAGERY AT 011800Z INDICATES THAT A CIRCULATION CENTER IS LOCATED
NEAR 17.8N 113.3E. THE SYSTEM IS MOVING NORTHWESTWARD AT 03
KNOTS.
2. REMARKS: THE AREA OF CONVECTION (INVEST 96W) PREVIOUSLY LOCATED
NEAR 18.2N 114.7E, IS NOW LOCATED NEAR 17.8N 113.3E, APPROXIMATELY
270 NM SOUTH OF HONG KONG. ANIMATED ENHANCED INFRARED SATELLITE
IMAGERY DEPICTS BROAD TURNING. A 011320Z METOP-A 89GHZ MICROWAVE
IMAGE SHOWS MINIMAL CONVECTION OVER THE ELONGATED CENTER AND
FORMATIVE LOW LEVEL BANDING WRAPPING IN. WINDS ARE STRONGER TO THE
SOUTH OVER THE SOUTH CHINA SEA DUE TO SOUTHWESTERLY MONSOONAL FLOW.
THE OVERALL ENVIRONMENT IS MARGINALLY UNFAVORABLE FOR FURTHER
DEVELOPMENT. THE SYSTEM IS ON THE BORDER OF A HIGH VERTICAL WIND
SHEAR AREA (25-35 KTS) TO THE SOUTHEAST. SEA SURFACE TEMPERATURES
ARE FAVORABLE, 30-32 CELSIUS, BUT THERE IS MARGINAL DIFFLUENCE
ALOFT. GLOBAL MODELS AGREE THAT THE SYSTEM WILL TRACK GENERALLY
WESTWARD OVER THE NEXT SEVERAL DAYS WITH SOME UNCERTAINTY IN THE
NEAR TERM. MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 18 TO 23
KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR
997 MB. 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
022100Z.
//
NNNN

[Nancy Smar]

WP, 96, 2019070118, , BEST, 0, 178N, 1133E, 20, 997, MD, 0, , 0, 0, 0, 0, 999, 145, 90, 0, 0, W, 0, , 0, 0, INVEST, S,

[wxman57]

I don't buy JMA's designation as a TD. Visible imagery shows a weak low-level swirl near 18.6N / 113.3E. No convection anywhere near it. Doesn't qualify for TD status.

[euro6208]

THE AREA OF CONVECTION PREVIOUSLY LOCATED NEAR 18.2N 114.7E,
IS NOW LOCATED NEAR 18.8N 112.3E, APPROXIMATELY 90 NM EAST OF HAINAN
ISLAND. ANIMATED ENHANCED MULTI-SPECTRAL SATELLITE IMAGERY DEPICTS
BROAD TURNING WITH LIMITED FLARING CONVECTION. A 020232Z METOP-C ASCAT
IMAGE SHOWS A CLOSED LOW LEVEL CIRCULATION CENTER (LLCC) WITH 20 KNOT
WINDS LOCATED WITHIN AN AREA OF FLARING CONVECTION. WINDS ARE STRONGER
TO THE SOUTHEAST OVER THE SOUTH CHINA SEA DUE TO SOUTHWESTERLY
MONSOONAL FLOW. THE OVERALL ENVIRONMENT IS MARGINALLY FAVORABLE FOR
FURTHER DEVELOPMENT WITH MODERATE TO HIGH (15-25 KNOTS) VERTICAL WIND
SHEAR IN THE VICINITY OF THE LLCC. SEA SURFACE TEMPERATURES IN THE
SOUTH CHINA SEA ARE FAVORABLE AT 30-32 CELSIUS HOWEVER THERE IS
MARGINAL DIFFLUENCE ALOFT. GLOBAL MODELS AGREE THAT THE SYSTEM WILL
TRACK GENERALLY WESTWARD AND INTENSIFY OVER THE NEXT SEVERAL DAYS WITH
SOME UNCERTAINTY IN THE DIRECTION IN THE NEAR TERM. MAXIMUM SUSTAINED
SURFACE WINDS ARE ESTIMATED AT 18 TO 23 KNOTS. MINIMUM SEA LEVEL
PRESSURE IS ESTIMATED TO BE NEAR 998 MB. THE POTENTIAL FOR THE
DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24 HOURS
REMAINS HIGH.

[Nancy Smar]

WTPQ20 RJTD 021200
RSMC TROPICAL CYCLONE ADVISORY
NAME TS 1904 MUN (1904) UPGRADED FROM TD
ANALYSIS
PSTN 021200UTC 18.9N 111.5E FAIR
MOVE W 09KT
PRES 994HPA
MXWD 035KT
GUST 050KT
30KT 400NM SOUTHEAST 240NM NORTHWEST
FORECAST
24HF 031200UTC 20.2N 108.4E 50NM 70%
MOVE WNW 08KT
PRES 992HPA
MXWD 035KT
GUST 050KT
48HF 041200UTC 21.5N 105.8E 90NM 70% TROPICAL DEPRESSION =

Excuse me? Why？

[euro6208]

Guessing games. They need to fix their 3rd world warnings.

I like how JTWC and NHC do their reasoning and discussion...

[euro6208]

I know there the RSMC but just imagine living in a very poor country and you had to rely on them...Guessing games and this simple map. Don't you need more information?

[Grifforzer]

WTPQ30 RJTD 021200
RSMC TROPICAL CYCLONE PROGNOSTIC REASONING
REASONING NO. 6 FOR TS 1904 Mun (1904)

1.General comments
A TD previously located at 18.8N 112.4E has been upgraded to TS (MUN). TS MUN is located at 18.9N, 111.5E. Information on the current position is based on animated msi and surface observations. Positional accuracy is fair. The system is in a favorable environment for development under the influence of high SSTs and high TCHP This has caused the system to develop over the last six hours. Information on current intensity is based on surface observations.

2.Synoptic situation
The system is moving westward due to weak steering flow. Animated msi shows cb clusters are scattered around the csc.

3.Track forecast
The system will move west-northwestward due to weak steering flow until ft48. The JMA track forecast is based on gsm predictions, and reference to other NWP models. JMA track forecast confidence is fair because all numerical models are in close agreement.

4.Intensity forecast
The system will develop until ft24 due to the influence of interaction with high SSTs and high TCHP. The system will the weaken until ft48 due to its landfall. The system will weaken to tropical depression intensity by ft48. The JMA intensity forecast is based on a consensus of guidance data including gsm.