WPAC: PODUL - Tropical Storm

[Nancy Smar]

99W INVEST 190822 0000 5.0N 160.0E WPAC 15 0

[Hayabusa]

We meet again mother of all invests

[Hayabusa]

JMA is more west and north

LOW PRESSURE AREA 1008 HPA NEAR 07N 154E ALMOST STATIONARY.

[euro6208]

Trending stronger on GFS and EURO.

[euro6208]

Generally fair weather is seen at Chuuk and Pohnpei this morning
despite the IR satellite imagery showing a lot of weather across the
region. The broad, weak circulation in the region much of this week
has shifted westward, now just south of Chuuk near 5N152E. Showers
and thunderstorms are found on the western semicircle of this
circulation, with all the action south to west of Weno. This weather
will continue west. More showers and thunderstorms are seen east and
southeast of the center within the area of convergence of trade
winds the east and south/southeast flow closer to the circulation.
This weather is near Kosrae and will close in on Pohnpei by tonight
as the mass shifts westward. Trade-wind convergence near and north
of Majuro is under the influence of a broad area of upper-level
divergence south of an upper-level low near Wake Island. Upper-level
support of thunderstorms will slowly diminish through tonight as the
upper low shifts WSW.

Little development is expected with the disturbance near Chuuk as it
heads west. However, an unsettled showery pattern will persist
through the end of the week at Pohnpei and Chuuk until this all
moves west. Expect improving weather on Friday at Kosrae. A quieter
weather pattern will follow in the wake of the disturbance, but
increased trade wind convergence Sunday and Monday could bring more
showers to the region then.

Looking ahead, a circulation near Chuuk will head generally west the
next couple days and be the primary weather feature this weekend.
Isolated showers and thunderstorms will move in at Yap and Koror
Saturday, likely becoming scattered by Sunday. Current forecast
reflects the increase in showers for Sunday and Monday.

The weekend forecast remains a low-confidence forecast at this time,
but model forecast trends have been showing a little more
development with this circulation than has been seen the last few
days. GFS tends to keep this circulation south of 10N until it
reaches Yap, then takes it over Yap Sunday and WNW toward the
Philippines. NAVGEM and ECMWF carry the circulation WNW the next
couple days and keep it north of Yap on Sunday, farther north than
the GFS. Will be watching the evolution of this circulation closely,
as well as subsequent model runs the next few days. At the least,
Yap and Koror should expect a showery weekend, lasting into the
coming week. Monsoonal southwest/west winds will strengthen
Sunday/Monday in the region as the circulation nears and passes by.
As a result seas and surf will build. Latest Wave Watch 3 model
shows higher seas than forecast the last few days. For now, bumped
up combined seas to between 5 and 6 feet by Sunday.

[Hayabusa]

If you look at the HWRF wide view version forecast for Bailu you'll see on the lower right side it also develops 99W, which as of now 99W isn't on the HWRF run list. But eh, the HWRF has been wacky this year when you bring up the previous invests/storms that HWRF hyped and didn't materialize. Let's see.

[Nancy Smar]

99W INVEST 190822 0000 6.1N 155.9E WPAC 15 1010

[doomhaMwx]

It appears that the environmental setup with 99W will be generally the same as with TC Bailu. So perhaps, a track and intensity which is more or less similar with Bailu can be anticipated. But of course, it's still too early to say at this point.

[Hayabusa]

ABPW10 PGTW 231000
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/SIGNIFICANT TROPICAL WEATHER ADVISORY FOR THE WESTERN AND
/SOUTH PACIFIC OCEANS REISSUED/231000Z-240600ZAUG2019//
REF/A/MSG/JOINT TYPHOON WRNCEN PEARL HARBOR HI/230751ZAUG2019//
AMPN/REF A IS A TROPICAL CYCLONE WARNING.//
RMKS/
(1) AN AREA OF CONVECTION (INVEST 99W) HAS PERSISTED NEAR 6.8N
145.1E, APPROXIMATELY 394 NM SOUTH OF GUAM. ANIMATED MULTISPECTRAL
SATELLITE IMAGERY, SUPPORTED BY A 230612Z SSMIS F-16 91GHZ MICROWAVE
IMAGE, SHOWS BUILDING DEEP CONVECTION OBSCURING A BROAD AND
DISORGANIZED LOW LEVEL CIRCULATION (LLC). A 230010Z METOP-B ASCAT
PASS SIMILARLY REVEALS THE LLC TO BE VERY DISORGANIZED AND SHOWS 10
TO 15 KNOT WINDS SURROUNDING THE LLC. 99W IS CURRENTLY IN A MARGINAL
ENVIRONMENT WITH VERY WARM (29 TO 30 CELSIUS) SEA SURFACE
TEMPERATURES BEING OFFSET BY MARGINAL UPPER LEVEL OUTFLOW AND
MODERATE (20 TO 25 KNOT) VERTICAL WIND SHEAR. GLOBAL MODELS ARE IN
GOOD AGREEMENT THAT 99W WILL TRACK GENERALLY WEST-NORTHWEST AND
INTENSIFY OVER THE NEXT SEVERAL DAYS. 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.

[Nancy Smar]

ABPW10 PGTW 240200
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/SIGNIFICANT TROPICAL WEATHER ADVISORY FOR THE WESTERN AND
/SOUTH PACIFIC OCEANS REISSUED/240200Z-240600ZAUG2019//
REF/A/MSG/JOINT TYPHOON WRNCEN PEARL HARBOR HI/231951ZAUG2019//
AMPN/REF A IS A TROPICAL CYCLONE WARNING.//
RMKS/
1. WESTERN NORTH PACIFIC AREA (180 TO MALAY PENINSULA):
A. TROPICAL CYCLONE SUMMARY:
(1) AT 23AUG19 1800Z, TROPICAL STORM 12W (BAILU) WAS LOCATED NEAR
20.7N 123.3E, APPROXIMATELY 200 NM EAST-SOUTHEAST OF KAOHSIUNG, TAIWAN,
AND HAD TRACKED NORTHWESTWARD AT 12 KNOTS OVER THE PAST SIX HOURS.
MAXIMUM SUSTAINED SURFACE WINDS WERE ESTIMATED AT 55 KNOTS GUSTING TO 70
KNOTS. SEE REF A (WTPN31 PGTW 232100) FOR FURTHER DETAILS.
(2) NO OTHER TROPICAL CYCLONES.
B. TROPICAL DISTURBANCE SUMMARY:
(1) THE AREA OF CONVECTION PREVIOUSLY LOCATED NEAR 6.8N 145.1E, IS
NOW LOCATED NEAR 7.9N 139.8E, APPROXIMATELY 140 NM SOUTHEAST OF YAP.
ANIMATED MULTISPECTRAL SATELLITE IMAGERY, SUPPORTED BY A 232349Z MHS
METOP-B 89 GHZ MICROWAVE IMAGE, DEPICTS A BROAD, MIDLEVEL TURNING WITH
EXPANSIVE, DISORGANIZED CONVECTION AND A WEAK, SLOWLY CONSOLIDATING
CIRCULATION. A 232351Z METOP-B ASCAT PASS SIMILARLY REVEALS A
DISORGANIZED AND BROAD LOW LEVEL CIRCULATION SURROUNDED BY 10-15 KNOT
WIND BARBS. 99W IS IN A MARGINAL ENVIRONMENT WITH VERY WARM (29 TO 31
CELSIUS) SEA SURFACE TEMPERATURES, OFFSET BY MARGINAL UPPER LEVEL
OUTFLOW AND MODERATE (15 - 25 KNOT) VERTICAL WIND SHEAR. GLOBAL MODELS
ARE IN GOOD AGREEMENT THAT 99W WILL TRACK GENERALLY WEST-NORTHWEST AND
INTENSIFY OVER THE NEXT SEVERAL DAYS. MAXIMUM SUSTAINED SURFACE WINDS
ARE ESTIMATED AT 15 TO 20 KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED
TO BE NEAR 1007 MB. THE POTENTIAL FOR THE DEVELOPMENT OF A SIGNIFICANT
TROPICAL CYCLONE WITHIN THE NEXT 24 HOURS IS UPGRADED TO MEDIUM.
(2) NO OTHER SUSPECT AREAS.
2. SOUTH PACIFIC AREA (WEST COAST OF SOUTH AMERICA TO 135 EAST):
A. TROPICAL CYCLONE SUMMARY: NONE.
B. TROPICAL DISTURBANCE SUMMARY: NONE.
3. JUSTIFICATION FOR REISSUE: UPGRADED TO MEDIUM//
NNNN

[Hayabusa]

Convection has significantly waned compared to just before last midnight... diurnal cycle?

[euro6208]

726
WWPQ82 PGUM 240809
SPSPQ2

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE TIYAN GU
609 PM ChST Sat Aug 24 2019

PMZ161-171-172-250815-
KOROR PALAU-YAP-CHUUK-
609 PM ChST Sat Aug 24 2019

...TROPICAL DISTURBANCE MOVING SLOWLY INTO EASTERN YAP STATE...

A WEAKLY DEFINED TROPICAL DISTURBANCE IS CENTERED EAST OF YAP NEAR
8N143E. THIS SYSTEM IS EXPECTED TO DRIFT SLOWLY TOWARD THE WEST-
NORTHWEST WITH LITTLE CONSOLIDATION OVER THE NEXT COUPLE OF DAYS.
LATEST GUIDANCE HAS IT PASSING JUST NORTH OF YAP SOMETIME ON SUNDAY.
ALTHOUGH LITTLE INTENSIFICATION IS EXPECTED...PERIODS OF HEAVY
SHOWERS AND THUNDERSTORMS ARE LIKELY ACROSS PORTIONS OF WESTERN YAP
STATE AND PALAU...ESPECIALLY JUST WEST AND SOUTH OF THE BROAD CENTER
IN THE WESTERLY WINDS WHERE GUSTS OF 20 TO 30 MPH ARE POSSIBLE.


FOR CHUUK STATE...CONVERGENCE EAST OF THE CENTER WILL PRODUCE
PERIODS OF HEAVY SHOWERS AND THUNDERSTORMS THROUGH SUNDAY OVER
PORTIONS OF WESTERN CHUUK STATE INCLUDING THE ISLANDS OF PULUWAT AND
ULUL.

THE DISTURBANCE WILL BE CLOSELY MONITORED FOR THE NEXT FEW DAYS.
RESIDENTS OF WESTERN CHUUK STATE...YAP STATE AND PALAU SHOULD MONITOR
THE LATEST FORECASTS AND ADVISORIES. HEED INSTRUCTIONS FROM LOCAL
EMERGENCY MANAGEMENT AND WEATHER SERVICE OFFICES. FOR MORE
INFORMATION ON THE LATEST FORECAST AND ADVISORIES...VISIT THE WFO
GUAM WEBSITE AT WWW.WEATHER.GOV/GUM/

$$

ZIOBRO

[euro6208]

Taiwan again?

[euro6208]

GFS being GFS.

Had a typhoon for Vietnam but 06Z barely even develops it.

[Hayabusa]

Upgraded to non warning TD

WWJP27 RJTD 250000
WARNING AND SUMMARY 250000.
WARNING VALID 260000.
WARNING IS UPDATED EVERY 6 HOURS.
TROPICAL DEPRESSION 1006 HPA AT 11N 139E WEST SLOWLY.

[Hayabusa]

HWRF looks more defined in this 00z.

[Nancy Smar]

2019/8/25 05:30:36: [TCFA]
WTPN21 PGTW 250600
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE FORMATION ALERT (INVEST 99W)//
RMKS/
1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN
140 NM EITHER SIDE OF A LINE FROM 9.6N 138.3E TO 13.4N 131.4E 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 20 TO 25 KNOTS. METSAT IMAGERY AT 250530Z
INDICATES THAT A CIRCULATION CENTER IS LOCATED NEAR 10.0N 138.0E.
THE SYSTEM IS MOVING NORTHWESTWARD AT 11 KNOTS.
2. REMARKS: THE AREA OF CONVECTION (INVEST 99W) PREVIOUSLY LOCATED
NEAR 7.9N 139.5E, IS NOW LOCATED NEAR 10.0N 138.0E, APPROXIMATELY 30
NM NORTH-NORTHWEST OF YAP. ANIMATED MULTISPECTRAL SATELLITE IMAGERY
AND A 242353Z MHS 89GHZ MICROWAVE IMAGE DEPICT A BROAD LOW LEVEL
CIRCULATION WITH FLARING CONVECTION OVER THE WESTERN SEMICIRCLE. A
250035Z PARTIAL ASCAT-C IMAGE SHOWS 20-25 KNOT WINDS OVER THE
EASTERN SEMICIRCLE. UPPER LEVEL ANALYSIS REVEALS A MARGINALLY
FAVORABLE ENVIRONMENT WITH MODERATE TO HIGH (20-25 KNOTS) VERTICAL
WIND SHEAR OFFSET BY STRONG DIFFLUENCE ALOFT. GLOBAL MODELS ARE IN
GOOD AGREEMENT SHOWING 99W TRACKING WEST-NORTHWESTWARD TOWARD LUZON
WITH SLOW CONSOLIDATION OVER THE NEXT TWO DAYS. MAXIMUM SUSTAINED
SURFACE WINDS ARE ESTIMATED AT 20 TO 25 KNOTS. MINIMUM SEA LEVEL
PRESSURE IS ESTIMATED TO BE NEAR 1004 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
260600Z.//
NNNN

[Hayabusa]

Yup...

[Hayabusa]

TD warning

TD
Issued at 01:20 UTC, 26 August 2019

<Analysis at 00 UTC, 26 August>
Scale -
Intensity -
TD
Center position N13°20' (13.3°)
E131°55' (131.9°)
Direction and speed of movement WNW 20 km/h (10 kt)
Central pressure 1004 hPa
Maximum sustained wind speed 15 m/s (30 kt)
Maximum wind gust speed 23 m/s (45 kt)

[Nancy Smar]

WTPQ20 RJTD 260000
RSMC TROPICAL CYCLONE ADVISORY
NAME TD
ANALYSIS
PSTN 260000UTC 13.3N 131.9E POOR
MOVE WNW 10KT
PRES 1004HPA
MXWD 030KT
GUST 045KT
FORECAST
24HF 270000UTC 14.7N 126.6E 80NM 70%
MOVE WNW 14KT
PRES 1000HPA
MXWD 035KT
GUST 050KT =