WPAC: CHABA - Severe Tropical Storm

[supercane]

Link to NRL 95W page
.95WINVEST.15kts-1010mb-156N-1695E.

[StormingB81]

From JMA:

Is this the same one?

LOW PRESSURE AREA 1010 HPA NEAR 17N 151E ALMOST STATIONARY.

[supercane]

Yes, from the NRL site:
.95WINVEST.15kts-1010mb-168N-1520E.

ASCAT only caught eastern edge, ?slight circulation but looks more troughy.

[supercane]

18Z JMA analysis:
LOW PRESSURE AREA 1008 HPA NEAR 16N 149E WNW 15 KT.



JTWC reissued significant tropical weather advisory to include this area, but development chances only poor.
ABPW10 PGTW 192000
MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC//
SUBJ/SIGNIFICANT TROPICAL WEATHER ADVISORY FOR THE WESTERN AND
/SOUTH PACIFIC OCEANS REISSUED/192000Z-200600ZOCT2010//
REF/A/MSG/NAVMARFCSTCEN PEARL HARBOR HI/191351ZOCT2010//
AMPN/REF A IS A TROPICAL CYCLONE WARNING.//
RMKS/
1. WESTERN NORTH PACIFIC AREA (180 TO MALAY PENINSULA):
A. TROPICAL CYCLONE SUMMARY:
(1) AT 191200Z, TYPHOON 15W (MEGI) WAS LOCATED NEAR 16.7N
117.9E, APPROXIMATELY 395 NM SOUTHEAST OF HONG KONG, AND HAD
TRACKED WEST-NORTHWESTWARD AT 05 KNOTS OVER THE PAST SIX HOURS.
MAXIMUM SUSTAINED SURFACE WINDS WERE ESTIMATED AT 100 KNOTS GUSTING
TO 125 KNOTS. SEE REF A (WTPN31 PGTW 191500) FOR FURTHER DETAILS.
(2) NO OTHER TROPICAL CYCLONES.
B. TROPICAL DISTURBANCE SUMMARY:
(1) AN AREA OF CONVECTION HAS PERSISTED NEAR 16.3N 148.8E,
APPROXIMATELY 280 NM NORTHEAST OF GUAM. ANIMATED INRARED IMAGERY
INDICATES PERSISTENT DEEP CONVECTION ASSOCIATED WITH A DEVELOPING
LOW LEVEL CIRCULATION CENTER (LLCC) EAST OF THE MARIANAS. A 191050Z
ASCAT PASS SHOWS A DEFINED LLCC WITH FRESH EASTERLIES ALONG THE
20TH LATITUDE. SURFACE OBSERVATIONS FROM ROTA AND SAIPAN SHOW LIGHT
WESTERLY WINDS, AS WELL AS 2.5MB 24 PRESSURE FALLS AT SAIPAN. A
191614Z AMSU 89GHZ MICROWAVE IMAGE SHOWS CONVECTION ORGANIZING
AROUND THE LLCC. THE 191200Z 200MB STREAMLINE ANALYSIS SHOWS LLCC
IS CURRENTLY UNDERNEATH AN AREA OF DIFFLUENCE AND MODERATE VERTICAL
WINDSHEAR (VWS), HOWEVER, WESTWARD MOVEMENT OF THE LLCC WILL BRING
THE SYSTEM UNDER INCREASING VWS ASSOCIATED WITH A BROAD TUTT CELL
CENTERED NEAR 18N 140E WHICH IS INDUCING SIGNIFICANT UPPER LEVEL
CONVERGENCE OVER THE MARIANAS. MAXIMUM SUSTAINED SURFACE WINDS ARE
ESTIMATED AT 10 TO 15 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 IS POOR.
(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: ADDED POOR AREA IN PARA 1.B.(1).//

[euro6208]

this is moving to an area with decreasing wind shear. I hope it develops

[StormingB81]

Well NOGAPS Develops it then brings it headed NW See what happends...They all need to stay away from PI though for the rest of the year they need time to recover!

[Chacor]

JMA
LOW PRESSURE AREA 1008 HPA NEAR 16N 149E WNW 15 KT.

[StormingB81]

this is moving to an area with decreasing wind shear. I hope it develops

Also remember what the people in PI went through to say this when peoples nerves are already shot because of Megi. just watch how you say things.

[euro6208]

i see this one recurving out to sea affecting no one

[cycloneye]

i see this one recurving out to sea affecting no one

What is your reasoning for that affirmation?

[euro6208]

just a forecast

[StormingB81]

NOGAPS Has 95 Recurving nad 97 going NW but stil lwayy to early to tell. long time between now and then and alot can happend..plus if (97) turns NW it will hit the waters that MEGI just went through and wont develop.

Personal Forecast Disclaimer:
The posts in this forum are NOT official forecast and should not be used as such. They are just the opinion of the poster and may or may not be backed by sound meteorological data. They are NOT endorsed by any professional institution or storm2k.org. For official information, please refer to the NHC and NWS products.

[StormingB81]

Still looks like alot of shear out there anyways for anything right now.

[supercane]

JMA upgrades to a depression at 00Z:
TROPICAL DEPRESSION 1006 HPA AT 16N 148E WEST 10 KT.

[HURAKAN]

Latest

[supercane]

Latest microwave shows a low-level circulation but not a lot of convection:


Convincing circulation on ASCAT with 30kt winds:


12Z models:

[supercane]

From NWS Guam discussion looks like there is reluctance to upgrade in anticipation of a more sheared environment ahead:

000
FXPQ60 PGUM 192127
AFDPQ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TIYAN GU
727 AM CHST WED OCT 20 2010

.SYNOPSIS...
PGUA WSR-88D SHOWS SCATTERED SHOWERS ASSOCIATED WITH A TROPICAL
DISTURBANCE MOVING INTO THE MARIANAS FROM THE NORTHEAST. WINDS IN
THE MARIANAS HAVE TURNED TO THE SOUTHWEST AND PRESSURES HAVE
FALLEN AS THE WEAK CIRCULATION COMES NEAR.

&&

.DISCUSSION...
THIS WEAK CIRCULATION SHOULD BE AT ITS PEAK NOW...IT IS MOVING
INTO A REGION OF INCREASED VERTICAL WIND SHEAR AND SUBSIDENCE. IT
WOULD HAVE TO SIGNIFICANTLY MODIFY ITS ENVIRONMENT TO HAVE A GOOD
SHOT AT DEVELOPING FURTHER. WHILE THIS IS POSSIBLE...IT IS NOT
EXPECTED. NEVERTHELESS...ON RADAR AT 4 AM IT SEEMED LIKE A GOOD
IDEA TO UPGRADE TINIAN AND SAIPAN TO SCATTERED SHOWERS. MOST
LIKELY CAUSE FOR ANY UPDATES WOULD BE IF IT BECAME NECESSARY TO
EXTEND THE SCATTERED SHOWERS TO GUAM AND ROTA. AT THE NEXT
ISSUANCE IT MAY ALSO BE NECESSARY TO EXTEND THE SHOWERS IN TIME...
DEPENDING ON HOW THE SITUATION DEVELOPS ON RADAR AND SATELLITE.
THE SHEAR AND OTHER HAMPERING ENVIRONMENTAL FEATURES ARE WHY JTWC
HAS LISTED THIS AS A POOR AREA FOR TROPICAL DEVELOPMENT VS A FAIR.

[StormingB81]

JTWC UPGRADES TO FAIR:

1) THE AREA OF CONVECTION PREVIOUSLY LOCATED NEAR 16.3N
148.0E, IS NOW LOCATED NEAR 15.9N 147.8E, APPROXIMATELY 150 NM EAST-
NORTHEAST OF SAIPAN. THE AREA OF CONVECTION PREVIOUSLY LOCATED NEAR
16.3N 148.0E IS NOW LOCATED NEAR 15.9N 147.8E. ANIMATED
MULTISPECTRAL IMAGERY SHOWS INCREASED CONVECTION ASSOCIATED WITH A
DEVELOPING LOW LEVEL CIRCULATION CENTER (LLCC). ALSO, A 192055Z
37GHZ TRMM MICROWAVE PASS SHOWS IMPROVED CONVECTIVE ORGANIZATION.
SURFACE OBSERVATIONS FROM SAIPAN, ROTA, AND GUAM SHOW 24 HR
PRESSURE FALLS OF 4MB, 3MB, 2MB RESPECTIVELY. THE LLCC IS CURRENTLY
LOCATED IN AN AREA OF LOW VERTICAL WIND SHEAR. THE AREA OF UPPER
LEVEL CONVERGENCE SUPPRESSING CONVECTION OVER THE MARIANAS ISLANDS
HAS WEAKENED IN ASSOCIATION WITH A RETREATING TUTT CELL, ALLOWING
IMPROVEMENT IN THE UPPER LEVEL ENVIRONMENT. MAXIMUM SUSTAINED
SURFACE WINDS ARE ESTIMATED AT 12 TO 18 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 IS UPGRADED TO FAIR.

[euro6208]

wow this is so organized but not upgraded? this already looks like a mature ts

[StormingB81]

JMA issuing advisories now
TD
Issued at 07:25 UTC, 20 October 2010
<Analyses at 20/06 UTC>
Scale -
Intensity -
TD
Center position N15°55'(15.9°)
E146°50'(146.8°)
Direction and speed of movement W 20km/h(10kt)
Central pressure 1004hPa
Maximum wind speed near the center 15m/s(30kt)
Maximum wind gust speed 23m/s(45kt)

<Forecast for 21/06 UTC>
Intensity -
Center position of probability circle N16°00'(16.0°)
E142°00'(142.0°)
Direction and speed of movement W 20km/h(12kt)
Central pressure 1000hPa
Maximum wind speed near the center 18m/s(35kt)
Maximum wind gust speed 25m/s(50kt)
Radius of probability circle 220km(120NM)