WPAC: DIANMU - Post-Tropical

[stormwise]

95W INVEST 160814 0600 20.7N 114.4E WPAC 15 NA





Pressure in the region of the monsoon low.

[euro6208]

AN AREA OF CONVECTION (INVEST 95W) HAS PERSISTED NEAR
20.7N 114.5E, APPROXIMATELY 95 NM SOUTH OF HONG KONG. ANIMATED
MULTISPECTRAL SATELLITE IMAGERY DEPICTS A BROAD MID-LEVEL
CIRCULATION WITH CONVECTION AROUND THE PERIPHERY. A 140426Z RSCAT
PASS INDICATED A CLOSED CIRCULATION WITH 10-15 KNOT WINDS. AN
OBSERVATION 60 NM TO THE WEST REPORTS ONLY 5 KNOT WINDS. A 140954Z
CORIOLIS 37 GHZ MICROWAVE IMAGE REVELAS BROAD MONSOONAL TROUGHING.
SEVERAL MODELS ARE INITIALIZING WITH A WEAK LOW LEVEL CIRCULATION
CENTER (LLCC) THAT GRADUALLY DRIFTS WESTWARD. UPPER LEVEL ANALYSIS
INDICATES THE DISTUBANCE IS LOCATED IN A NARROW REGION OF LIGHT (10-
15 KNOTS) VERTICAL WIND SHEAR WITH GOOD DIFFLUENT OUTFLOW. MEAN SEA
LEVEL PRESSURES IN THE AREA ARE VERY LOW, NEAR 996 MB. MAXIMUM
SUSTAINED SURFACE WINDS ARE ESTIMATED AT 10 TO 15 KNOTS. MINIMUM SEA
LEVEL PRESSURE IS ESTIMATED TO BE NEAR 996 MB. THE POTENTIAL FOR THE
DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24
HOURS IS LOW.

[euro6208]

EURO moves this inland west of Hong Kong, though Leizhou Peninsula, strengthens to a peak of 983mb over the Gulf of Tonkin, and finally hits Vietnam...

GFS zilch...

[dexterlabio]

I don't know if this system is to be blamed for days of bad weather in Luzon (I guess it's just the active monsoon in general). Anyway, a band of thick convection spawned a tornado right into the center of the Philippines' capital city.

https://twitter.com/krizzy_kalerqui/status/764761342611906560

[euro6208]

95W INVEST 160814 1800 21.3N 115.8E WPAC 15 997

[euro6208]

EURO still forecasting some solid intensification for so little time it has. Track almost the same as previous run but now has a typhoon for Leizhou Peninsula.

GFS continues to be quiet with this...

[euro6208]

THE AREA OF CONVECTION (INVEST 95W) PREVIOUSLY LOCATED
NEAR 20.7N 114.5E IS NOW LOCATED NEAR 21.6N 116.1E, APPROXIMATELY
115NM EAST-SOUTHEAST OF HONG KONG. ANIMATED INFRARED SATELLITE
IMAGERY DEPICTS IMPROVED CONVECTIVE BANDING OVER THE SOUTHERN SEMI-
CIRCLE WITH DISORGANIZED CONVECTION OVER THE NORTHERN SEMI-CIRCLE. A
142015Z SSMIS 91GHZ IMAGE SHOWS A ELONGATED, CONSOLIDATING LOW-LEVEL
CIRCULATION CENTER WITH IMPROVED BANDING WRAPPING AROUND THE CENTER.
UPPER-LEVEL ANALYSIS INDICATES A MARGINALLY-FAVORABLE ENVIRONMENT
WITH LOW VERTICAL WIND SHEAR AND DIFFLUENCE ALOFT. DYNAMIC MODEL
GUIDANCE DEPICTS QUASI-STATIONARY TRACK MOTION NEAR THE COAST OF
CHINA OVER THE NEXT 24 HOURS WITH SLOW INTENSIFICATION ASSOCIATED
WITH A SOUTHWEST MONSOONAL SURGE. MAXIMUM SUSTAINED SURFACE WINDS
ARE ESTIMATED AT 15 TO 20 KNOTS. MINIMUM SEA LEVEL PRESSURE IS
ESTIMATED TO BE NEAR 996 MB. THE POTENTIAL FOR THE DEVELOPMENT OF A
SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24 HOURS IS UPGRADED TO
MEDIUM.

[euro6208]

THE AREA OF CONVECTION (INVEST 95W) PREVIOUSLY LOCATED
NEAR 21.6N 116.1E, IS NOW LOCATED NEAR 22.5N 115.4E, APPROXIMATELY
70 NM EAST OF HONG KONG. ANIMATED MULTI-SPECTRAL SATELLITE IMAGERY
AND A 160148Z METOP-B 89GHZ MICROWAVE PASS DEPICT A POORLY
ORGANIZED, FRAGMENTED, AND SHALLOW BANDING WRAPPING LOOSELY AROUND
AN ILL-DEFINED LOW-LEVEL CIRCULATION CENTER (LLCC), EVIDENT ON A
160150Z 50KM AND 160235Z 25KM METOP-A ASCAT PASSES. THE COMBINED
ASCAT PASSES REVEAL 10 TO 15 KNOT AT THE CENTER. THE 50KM ASCAT PASS
DEPICTS 20 KNOTS ON THE SOUTHERN EDGE OF THE LLCC. UPPER-LEVEL
ANALYSIS INDICATES A MARGINAL ENVIRONMENT WITH 5 TO 15 KNOT VERTICAL
WIND SHEAR (VWS) AND UPPER-LEVEL DIVERGENCE EXTENDING FROM A POINT
SOURCE IN THE REGION. MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED
AT 15 TO 20 KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE
NEAR 1006 MB. DUE TO THE MARGINAL ENVIRONMENTAL CONDITION, THE
POTENTIAL FOR THE DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE
WITHIN THE NEXT 24 HOURS REMAINS MEDIUM.

[euro6208]

DATE TIME LAT LON CLASSIFICATION ID NAME
20160816 0230 22.4 -115.6 Too Weak 95W 95W
20160815 2030 21.5 -115.0 T1.0/1.0 95W 95W
20160815 1430 21.6 -116.1 T1.0/1.0 95W 95W

[1900hurricane]

I don't have a bunch of confidence at the moment (than again, what about the current period has exuded confidence), but I do think this will end up becoming the next named storm, beating out whatever ends up developing first out of the mess further east. It probably won't have enough room to get very strong though.

[stormwise]

TROPICAL DEPRESSION 95W ANALYSED POSITION : 22.1N 113.6E



VERIFYING TIME POSITION STRENGTH TENDENCY

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

12UTC 16.08.2016 22.1N 113.6E MODERATE

00UTC 17.08.2016 20.9N 111.8E MODERATE LITTLE CHANGE

12UTC 17.08.2016 20.6N 111.8E MODERATE INTENSIFYING SLIGHTLY

00UTC 18.08.2016 21.1N 110.6E MODERATE LITTLE CHANGE

12UTC 18.08.2016 21.2N 108.2E MODERATE LITTLE CHANGE

00UTC 19.08.2016 20.8N 105.8E MODERATE LITTLE CHANGE

12UTC 19.08.2016 20.5N 102.5E MODERATE WEAKENING SLIGHTLY

00UTC 20.08.2016 20.8N 98.1E MODERATE LITTLE CHANGE

12UTC 20.08.2016 BELOW TROPICAL STORM STRENGTH

THIS INFORMATION IS PROVIDED AS GUIDANCE FOR TROPICAL CYCLONE

RSMCS. IT REQUIRES INTERPRETATION BY TROPICAL CYCLONE SPECIALISTS

AND SHOULD NOT BE CONSIDERED AS A FINAL PRODUCT.

[euro6208]

THE AREA OF CONVECTION (INVEST 95W) PREVIOUSLY LOCATED
NEAR 21.6N 116.1E, IS NOW LOCATED NEAR 21.4N 113.4E, APPROXIMATELY
68 NM SOUTHWEST OF HONG KONG, CHINA. ANIMATED MULTI-SPECTRAL
SATELLITE IMAGERY AND A 161914Z 85GHZ MICROWAVE PASS DEPICT POORLY
ORGANIZED, FRAGMENTED, AND SHALLOW CONVECTION WRAPPING LOOSELY
AROUND AN ILL-DEFINED LOW-LEVEL CIRCULATION CENTER (LLCC), EVIDENT
ON THE 161344Z METOP-A ASCAT PASS WHICH DEPICTS WINDS OF 10 TO 15
KNOTS NEAR THE LLCC WITH 20 KNOTS ALONG THE SOUTHERN PERIPHERY OF
THE CIRCULATION. UPPER-LEVEL ANALYSIS INDICATES LOW VERTICAL WIND
SHEAR (5 TO 15 KNOTS) WITH GOOD EQUATORWARD OUTFLOW BUT RESTRICTED
POLEWARD. MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 15 TO 20
KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1006 MB.
THE POTENTIAL FOR THE DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE
WITHIN THE NEXT 24 HOURS REMAINS MEDIUM.

[kala]

Both ECMWF and GFS really like this thing's chances in the Gulf of Tonkin:

[Typhoon Hunter]

THE AREA OF CONVECTION (INVEST 95W) PREVIOUSLY LOCATED
NEAR 21.6N 116.1E, IS NOW LOCATED NEAR 21.4N 113.4E, APPROXIMATELY
68 NM SOUTHWEST OF HONG KONG, CHINA. ANIMATED MULTI-SPECTRAL
SATELLITE IMAGERY AND A 161914Z 85GHZ MICROWAVE PASS DEPICT POORLY
ORGANIZED, FRAGMENTED, AND SHALLOW CONVECTION WRAPPING LOOSELY
AROUND AN ILL-DEFINED LOW-LEVEL CIRCULATION CENTER (LLCC), EVIDENT
ON THE 161344Z METOP-A ASCAT PASS WHICH DEPICTS WINDS OF 10 TO 15
KNOTS NEAR THE LLCC WITH 20 KNOTS ALONG THE SOUTHERN PERIPHERY OF
THE CIRCULATION. UPPER-LEVEL ANALYSIS INDICATES LOW VERTICAL WIND
SHEAR (5 TO 15 KNOTS) WITH GOOD EQUATORWARD OUTFLOW BUT RESTRICTED
POLEWARD. MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 15 TO 20
KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1006 MB.
THE POTENTIAL FOR THE DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE
WITHIN THE NEXT 24 HOURS REMAINS MEDIUM.

Do JTWC not look at nearby weather observations?! Pressure has been hovering around 992hPa all day in Hong Kong...

[NotoSans]

JMA now expects this to become a TS within 24 hours.
And, again, their intensity estimate (992 hPa) seems more accurate.

TD
Issued at 13:30 UTC, 17 August 2016
<Analysis at 12 UTC, 17 August>
Scale -
Intensity -
TD
Center position N20°30' (20.5°)
E112°20' (112.3°)
Direction and speed of movement NW Slow
Central pressure 992 hPa
Maximum wind speed near center 15 m/s (30 kt)
Maximum wind gust speed 23 m/s (45 kt)

<Forecast for 12 UTC, 18 August>
Intensity -
Center position of probability circle N20°05' (20.1°)
E109°10' (109.2°)
Direction and speed of movement W 15 km/h (7 kt)
Central pressure 990 hPa
Maximum wind speed near center 18 m/s (35 kt)
Maximum wind gust speed 25 m/s (50 kt)
Radius of probability circle 200 km (110 NM)

[wxman57]

JMA is now issuing advisories on this depression.

http://www.jma.go.jp/en/typh/b.html

[NotoSans]

TCFA issued.



WTPN22 PGTW 171730
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE FORMATION ALERT//
REF/A/JOINT TYPHOON WRNCEN PEARL HARBOR HI/171551Z AUG 16//
AMPN/REF IS TROPICAL CYCLONE FORMATION ALERT (WTPN21 PGTW 171600)//
RMKS/
1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN
150 NM EITHER SIDE OF A LINE FROM 21.2N 114.6E TO 20.2N 108.0E
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 15 TO 20 KNOTS. METSAT
IMAGERY AT 171200Z INDICATES THAT A CIRCULATION CENTER IS LOCATED
NEAR 20.8N 113.0E. THE SYSTEM IS MOVING WEST-SOUTHWESTWARD AT 03
KNOTS.
2. REMARKS: THE AREA OF CONVECTION (INVEST 95W) PREVIOUSLY LOCATED
NEAR 21.2N 113.7E, IS NOW LOCATED NEAR 20.8N 113.0E, APPROXIMATELY
115 NM SOUTHWEST OF HONG KONG. ANIMATED ENHANCED INFRARED SATELLITE
IMAGERY DEPICTS INCREASED CENTRAL CONVECTION ASSOCIATED WITH A
CONSOLIDATING LOW LEVEL CIRCULATION CENTER (LLCC). A 171326Z ASCAT
PASS SHOWED A DEFINED LLCC WITH STRONG (25-30 KNOT) SOUTHWEST
MONSOON WINDS WRAPPING UP INTO THE LLCC WITH 15 TO 20 KNOT WINDS
ALONG THE NORTHERN PERIPHERY. ADDITIONALLY HONG KONG OBSERVATIONS
SHOW A 4MB DROP IN PRESSURE OVER THE PAST 24 HOURS WITH WINDS
GUSTING TO 23 KNOTS. THE UPPER LEVEL ENVIRONMENT IS FAVORABLE FOR
FURTHER DEVELOPMENT WITH LOW VERTICAL WIND SHEAR AND STRONG
DIVERGENCE ALOFT. GLOBAL MODELS SHOW FURTHER DEVELOPMENT AS THE
DISTURBANCE TRACKS WESTWARD. MAXIMUM SUSTAINED SURFACE WINDS ARE
ESTIMATED AT 15 TO 20 KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED
TO BE NEAR 990 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
181730Z.
4. SEE REF A FOR DETAILS ON A TROPICAL CYCLONE FORMATION ALERT
(INVEST 99W) LOCATED NEAR 15.2N 140.6E.//
NNNN

That's a MUCH MORE reasonable estimate.

[euro6208]

TPPN13 PGTW 171830

A. TROPICAL DISTURBANCE 95W (SW OF HONG KONG)

B. 17/1800Z

C. 20.89N

D. 112.30E

E. FIVE/HMWRI8

F. T1.0/1.0 STT: S0.0/03HRS

G. IR/EIR

H. REMARKS: 38A/PBO SBC/ANMTN. CNVCTN WRAPS .25 ON LOG10
SPIRAL, YIELDING A DT OF 1.0. MET AND PT ARE UNAVAILABLE. DBO
DT.

I. ADDITIONAL POSITIONS: NONE


CHAPPOTIN

[euro6208]

TXPQ29 KNES 171753
TCSWNP

A. TROPICAL DISTURBANCE (95W)

B. 17/1430Z

C. 20.7N

D. 112.6E

E. THREE/HIMAWARI-8

F. T1.0/1.0/D1.0/24HRS

G. IR/EIR/SWIR

H. REMARKS...SHEARED SYSTEM CHARACTERIZED BY SPIRAL/LOOSELY DEFINED
CLOUD LINES AND A CENTER THAT IS LOCATED LESS THAN 1.25 DEGREES FROM A
SMALL COLD OVERCAST. THIS YIELDS A DT OF 1.0. MET=1.0 AND PT=1.5. FT IS
BASED ON DT.

I. ADDL POSITIONS

NIL

[1900hurricane]

ATCF has it as 11W now.