WPAC: Tropical Depression Aere

[1900hurricane]

Invest 99W has been declared, and it may be the next in a growing line of Tropical Western Pacific systems (following Malakas, Megi, and Chaba) to develop from easterly waves born from an Intertropical Convergence Zone rather than a typical Monsoon Trough. Initial tag location as of 12Z is at 10.1*N, 160*E. Guidance is a little wishy-washy in developing 99W, probably due to dominating heights from subtropical ridging resulting in some subsidence in the vicinity of 99W's track, but I think development chances are rather good once it passes by the Marianas and enters the Philippine Sea, much like the previous few systems. After that, 99W may once again track towards the Luzon to southern Ryukyu area.

[euro6208]

Look what the EURO has in store.

[euro6208]

GFS still on the zilch wagon after showing runs of a powerful typhoon

[mrbagyo]

GFS is again showing a weak storm for Luzon then strengthens it in the SCS en route for Hainan.

[dexterlabio]

^Then it flipped back to nothing but a disorganized wave. Times like this, I switch to Euro hoping for more consistency. To be fair with the GFS, it was the first global model to pick up on this..the Euro only started to show a potent system out of this 2 runs ago.

[euro6208]

Much weaker on the 00Z EURO. 994 mb landfall near Hong Kong.

[euro6208]

Stronger with EURO. 989mb landfall west of Hong Kong.
'

[euro6208]

EURO 963 mb Hainan Island landfall...

[euro6208]

AN AREA OF CONVECTION (INVEST 99W) HAS PERSISTED NEAR
12.2N 146.6E, APPROXIMATELY 130 NM EAST-SOUTHEAST OF ANDERSON AB,
GUAM. ANIMATED MULTISPECTRAL IMAGERY SHOWS A BROAD AREA OF
CONVECTION THAT IS BEGINNING TO EXHIBIT LOW-LEVEL POSITIVE CURVATURE
VORTICITY. A 020415Z SSMI 85GHZ SATELLITE IMAGERY SHOWS BROKEN AND
SPOTTY CONVECTION. NO LOW LEVEL CIRCULATION CENTER (LLCC) IS
APPARENT YET, BUT SOME CURVATURE IN THE LOW-LEVEL CLOUD BANDS IS
EVIDENT. A 011206Z PARTIAL METOP-B ASCAT PASS SHOWS THE WESTERN
PERIPHERY OF A VERY BROAD CIRCULATION WITH WINDS BETWEEN 5-10 KNOTS.
THE SYSTEM IS LOCATED IN A FAVORABLE ENVIRONMENT WITH GOOD
DIVERGENCE ALOFT DUE TO EQUATORWARD OUTFLOW AND IS CURRENTLY IN AN
AREA OF LOW VERTICAL WIND SHEAR OF 5-10 KNOTS OVER WARM SEA SURFACE
TEMPERATURES. GLOBAL MODELS ARE IN MODERATE AGREEMENT THAT THE
SYSTEM WILL BEGIN TO CONSOLIDATE IN THE NEXT 48 HOURS AS IT MOVES TO
THE WEST-NORTHWEST. MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT
10 TO 15 KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR
1010 MB. THE POTENTIAL FOR THE DEVELOPMENT OF A SIGNIFICANT TROPICAL
CYCLONE WITHIN THE NEXT 24 HOURS IS LOW.

[euro6208]

NAVGEM seems to dissipate this into Luzon but later links it up with another system in the SCS where it further develops.

CMC recurves this before Taiwan and again the Japanese Islands in the brunt.

EURO with a mere 1001 mb striking Vietnam!

[euro6208]

GFS also weak. 1002 mb south of Hainan into Vietnam.

[euro6208]

THE AREA OF CONVECTION (INVEST 99W) PREVIOUSLY LOCATED
NEAR 12.2N 146.6E, IS NOW LOCATED NEAR 14.4N 139.5E, APPROXIMATELY
300 NM WEST OF ANDERSEN AB, GUAM. ANIMATED MULTISPECTRAL SATELLITE
IMAGERY DEPICTS A BROAD TURNING LOW LEVEL CIRCULATION CENTER (LLCC)
WITH AN AREA OF CONVECTION DIRECTLY OVER IT. A 030017Z AMSU-B 89GHZ
SATELLITE IMAGE SHOWS SEVERAL SMALL AREAS OF CONVECTION SURROUNDING
THE BROAD, ELONGATED LLCC. THE SYSTEM IS LOCATED IN A FAVORABLE
ENVIRONMENT WITH WARM SEA SURFACE TEMPERATURES, 5-10 KNOTS OF
VERTICAL WIND SHEAR, AND GOOD DIVERGENCE ALOFT PROVIDING UPPER LEVEL
OUTFLOW. GLOBAL MODELS ARE IN GOOD AGREEMENT THAT THE SYSTEM WILL
CONTINUE TO MOVE TO THE NORTHWEST AND FURTHER CONSOLIDATE OVER THE
NEXT 2-3 DAYS. MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 10
TO 15 KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1006
MB. DUE TO THE BROAD LLCC, THE POTENTIAL FOR THE DEVELOPMENT OF A
SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24 HOURS REMAINS LOW.

[euro6208]

THE AREA OF CONVECTION (INVEST 99W) PREVIOUSLY LOCATED
NEAR 12.2N 146.6E, IS NOW LOCATED NEAR 15N 137.9E, APPROXIMATELY 410
NM WEST-NORTHWEST OF ANDERSEN AB, GUAM. ANIMATED ENHANCED INFRARED
SATELLITE IMAGERY DEPICTS A BROAD AND ELONGATED LOW LEVEL
CIRCULATION CENTER (LLCC) WITH POCKETS OF CONVECTION SLOWLY
CONSOLIDATING AROUND IT. A 030912Z SSMIS 91GHZ MICROWAVE IMAGE SHOWS
INCREASED CONVECTION AROUND THE EASTERN EDGE OF THE LLCC. THE SYSTEM
IS CURRENTLY LOCATED IN AN AREA OF LOW VERTICAL WIND SHEAR (5-10
KNOTS), WARM SEA SURFACE TEMPERATURES, AND STRONG DIVERGENCE ALOFT
AS INDICATED IN THE UPPER LEVEL WIND OUTFLOW TO THE WEST. GLOBAL
MODELS ARE IN GOOD AGREEMENT IN SHOWING THE SYSTEM’S MOVEMENT TO THE
NORTHWEST OVER THE NEXT 2-3 DAYS WHILE CONSOLIDATING AND
STRENGTHENING. MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 10
TO 15 KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1006
MB. DUE TO THE IMPROVED CONSOLIDATION, THE POTENTIAL FOR THE
DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24
HOURS IS UPGRADED TO MEDIUM.

[euro6208]

EURO and GFS agrees on a track south of Hainan Island into Vietnam.

[euro6208]

TXPQ24 KNES 032111
TCSWNP

A. TROPICAL DISTURBANCE (99W)

B. 03/2030Z

C. 16.3N

D. 134.2E

E. THREE/HIMAWARI-8

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

G. IR/EIR/SWIR

H. REMARKS...CURVED BANDING WRAPS SLIGHTLY GREATER THAN .2 FOR
DT=1.0. MET AND PT AGREE. FT IS BASED ON DT.

I. ADDL POSITIONS

NIL


...VELASCO

[euro6208]

12Z EURO has a Meranti like track but veers it further west near Hong Kong. Typhoon in 48 hours.

[1900hurricane]

An F-17 pass from a few hours ago shows a well organized wave with good vorticity.

[1900hurricane]

SAB with the elusive DT of 0.

TXPQ24 KNES 040354
TCSWNP

A. TROPICAL DISTURBANCE (99W)

B. 04/0230Z

C. 17.7N

D. 133.1E

E. FIVE/HIMAWARI-8

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

G. IR/EIR/VIS

H. REMARKS...UNCERTAIN OF THE LOCATION OF THE CLOSED LOW. LT 0.2 CURVED
CONVECTIVE BANDING YIELDS A DT OF 0. MET AND PT ARE 1.0. FT IS BASED
ON MET.

I. ADDL POSITIONS

NIL


...RAMIREZ

[euro6208]

THE AREA OF CONVECTION (INVEST 99W) PREVIOUSLY LOCATED
NEAR 15N 137.9E, IS NOW LOCATED NEAR 17.7N 134.5E, APPROXIMATELY 650
NM SOUTHEAST OF OKINAWA. ANIMATED ENHANCED INFRARED
SATELLITE IMAGERY DEPICTS A BROAD AND ELONGATED LOW LEVEL
CIRCULATION CENTER (LLCC) WITH POCKETS OF CONVECTION SLOWLY
CONSOLIDATING AROUND IT. A 040526Z SSMI MICROWAVE IMAGE SHOWS
CONTINUED CONVECTION AROUND THE WESTERN AND SOUTHERN EDGES OF THE
LLCC. THE SYSTEM IS CURRENTLY LOCATED IN AN AREA OF LOW VERTICAL
WIND SHEAR (5-10 KNOTS), WARM SEA SURFACE TEMPERATURES, AND STRONG
DIVERGENCE ALOFT AS INDICATED IN THE UPPER LEVEL WIND OUTFLOW TO THE
WEST. GLOBAL MODELS ARE IN GOOD AGREEMENT IN SHOWING THE SYSTEM'S
MOVEMENT TO THE NORTHWEST OVER THE NEXT 2-3 DAYS WHILE CONSOLIDATING
AND STRENGTHENING. MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT
15 TO 20 KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR
1005 MB. DUE TO THE IMPROVED CONSOLIDATION, THE POTENTIAL FOR THE
DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24
HOURS IS MEDIUM.

[1900hurricane]

JMA is now classifying 99W as a Tropical Depression.

WWJP25 RJTD 041200
WARNING AND SUMMARY 041200.
WARNING VALID 051200.
WARNING IS UPDATED EVERY 6 HOURS.
STORM WARNING.
DEVELOPING LOW 974 HPA
AT 46N 156E SEA EAST OF KURILS MOVING EAST 15 KNOTS.
WINDS 30 TO 50 KNOTS WITHIN 800 MILES OF LOW SOUTHEAST SEMICIRCLE AND
600 MILES ELSEWHERE.
FORECAST POSITION FOR 050000UTC AT 48N 163E WITH UNCERTAINTY OF 50
MILES RADIUS.
FORECAST POSITION FOR 051200UTC AT 49N 170E WITH UNCERTAINTY OF 85
MILES RADIUS.
ANOTHER LOW 976 HPA AT 47N 163E
MOVING EASTNORTHEAST 25 KNOTS.
GALE WARNING.
TROPICAL DEPRESSION 1006 HPA
AT 16.5N 176.5E MIDWAYS MOVING WEST 10 KNOTS.
POSITION FAIR.
MAX WINDS 30 KNOTS NEAR CENTER.
EXPECTED MAX WINDS 35 KNOTS NEAR CENTER FOR NEXT 24 HOURS.
FORECAST POSITION FOR 050000UTC AT 17.1N 174.6E WITH 60 MILES RADIUS
OF 70 PERCENT PROBABILITY CIRCLE.
FORECAST POSITION FOR 051200UTC AT 17.7N 172.7E WITH 110 MILES RADIUS
OF 70 PERCENT PROBABILITY CIRCLE.
WARNING.
DENSE FOG OBSERVED LOCALLY OVER SEA OF OKHOTSK WESTERN PART OF SEA OF
JAPAN BOHAI YELLOW SEA.
WARNING.
DENSE FOG OBSERVED LOCALLY OVER WATERS BOUNDED BY 44N 147E 50N 156E
51N 168E 60N 167E 60N 180E 40N 180E 39N 170E 40N 162E 44N 160E 43N
151E 44N 147E.
SUMMARY.
LOW 988 HPA AT 57N 177E NE 20 KT.
TROPICAL DEPRESSION 1004 HPA AT 19N 130E WNW 15 KT.
HIGH 1022 HPA AT 41N 135E EAST 10 KT.
HIGH 1018 HPA AT 28N 148E EAST 10 KT.
STATIONARY FRONT FROM 33N 131E TO 31N 137E 31N 142E.
OCCLUDED FRONT FROM 47N 163E TO 47N 165E 47N 168E.
WARM FRONT FROM 47N 168E TO 46N 171E 44N 175E.
COLD FRONT FROM 47N 168E TO 40N 163E 35N 150E.
REMARKS.
TYPHOON 1618 CHABA (1618) 940 HPA AT 31.1N 125.9E : SEE TROPICAL
CYCLONE WARNING.

JAPAN METEOROLOGICAL AGENCY.=