WPAC: RAMMASUN - Post-Tropical

[dexterlabio]

06z GFS goes further south...something the Philippine capital must keep an eye on..

[stormcruisin]

no way is that sat-pic a TS on presentation its just not there yet maybe 30 knots.

[xtyphooncyclonex]

http://imageshack.com/a/img820/9294/lix.gif

no way is that sat-pic a TS on presentation its just not there yet maybe 30 knots.

It is now. Relocated center is RIGHT at the deep convection and outflow is impressive. DVORAK NOW at T2.5.
F. T2.5/2.5/D1.0/24HRS STT: D0.5/03HRS

[dexterlabio]

Doksuri 2012 even made it to 40kts but it was like a beheaded TC...it looked more sheared than this one.. Many times there were naked swirls declared by JTWC or JMA as TS. As for Rammasun, it looked really bad even as a TD last night. Now is the right timing for upgrade, IMO.




Well it seems like we have switched sides, stormcruisin.

[xtyphooncyclonex]

Doksuri 2012 even made it to 40kts but it was like a beheaded TC...it looked more sheared than this one.. Many times there were naked swirls declared by JTWC or JMA as TS. As for Rammasun, it looked really bad even as a TD last night. Now is the right timing for upgrade, IMO.




Well it seems like we have switched sides, stormcruisin.

Indeed. Right now, both JMA & JTWC also agree at the upgrade/position. This one looks like 40 kts on satellite.

[cycloneye]

Latest JMA warning.

TS 1409 (RAMMASUN)
Issued at 09:50 UTC, 12 July 2014
<Analyses at 12/09 UTC>
Scale -
Intensity -
Center position N13°30'(13.5°)
E141°40'(141.7°)
Direction and speed of movement W 30km/h(17kt)
Central pressure 1004hPa
Maximum wind speed near the center 18m/s(35kt)
Maximum wind gust speed 25m/s(50kt)
Area of 30kt winds or more ALL130km(70NM)

<Forecast for 12/21 UTC>
Intensity -
Center position of probability circle N13°25'(13.4°)
E138°55'(138.9°)
Direction and speed of movement W 25km/h(14kt)
Central pressure 1000hPa
Maximum wind speed near the center 20m/s(40kt)
Maximum wind gust speed 30m/s(60kt)
Radius of probability circle 90km(50NM)

<Forecast for 13/09 UTC>
Intensity -
Center position of probability circle N13°20'(13.3°)
E136°25'(136.4°)
Direction and speed of movement W 20km/h(12kt)
Central pressure 992hPa
Maximum wind speed near the center 25m/s(50kt)
Maximum wind gust speed 35m/s(70kt)
Radius of probability circle 140km(75NM)

<Forecast for 14/06 UTC>
Intensity Strong
Center position of probability circle N13°30'(13.5°)
E132°35'(132.6°)
Direction and speed of movement W 20km/h(12kt)
Central pressure 975hPa
Maximum wind speed near the center 35m/s(65kt)
Maximum wind gust speed 50m/s(95kt)
Radius of probability circle 260km(140NM)
Storm warning area ALL330km(180NM)

<Forecast for 15/06 UTC>
Intensity Strong
Center position of probability circle N14°05'(14.1°)
E127°40'(127.7°)
Direction and speed of movement W 20km/h(12kt)
Central pressure 955hPa
Maximum wind speed near the center 40m/s(80kt)
Maximum wind gust speed 60m/s(115kt)
Radius of probability circle 390km(210NM)
Storm warning area ALL480km(260NM)

[xtyphooncyclonex]

The topic has soo many pages now, at 12 pages which is typical of a major typhoon event. It has not even strengthened nor peaked yet hahaha.

[Alyono]

the center is NOT under the convection

JT made a really poor center fix

[cycloneye]

12z Best Track from JTWC upgrades to TS.

09W RAMMASUN 140712 1200 13.5N 141.7E WPAC 35 996

[cycloneye]

New warning by JMA:

TS 1409 (RAMMASUN)
Issued at 12:45 UTC, 12 July 2014
<Analyses at 12/12 UTC>
Scale -
Intensity -
Center position N13°30'(13.5°)
E141°05'(141.1°)
Direction and speed of movement W 30km/h(16kt)
Central pressure 1002hPa
Maximum wind speed near the center 18m/s(35kt)
Maximum wind gust speed 25m/s(50kt)
Area of 30kt winds or more ALL170km(90NM)

<Forecast for 13/00 UTC>
Intensity -
Center position of probability circle N13°20'(13.3°)
E138°05'(138.1°)
Direction and speed of movement W 30km/h(15kt)
Central pressure 998hPa
Maximum wind speed near the center 20m/s(40kt)
Maximum wind gust speed 30m/s(60kt)
Radius of probability circle 90km(50NM)

<Forecast for 13/12 UTC>
Intensity -
Center position of probability circle N13°05'(13.1°)
E135°55'(135.9°)
Direction and speed of movement W 20km/h(11kt)
Central pressure 990hPa
Maximum wind speed near the center 25m/s(50kt)
Maximum wind gust speed 35m/s(70kt)
Radius of probability circle 140km(75NM)

<Forecast for 14/12 UTC>
Intensity Strong
Center position of probability circle N13°30'(13.5°)
E131°30'(131.5°)
Direction and speed of movement W 20km/h(11kt)
Central pressure 970hPa
Maximum wind speed near the center 35m/s(70kt)
Maximum wind gust speed 50m/s(100kt)
Radius of probability circle 260km(140NM)
Storm warning area ALL330km(180NM)

<Forecast for 15/12 UTC>
Intensity Very Strong
Center position of probability circle N14°20'(14.3°)
E127°05'(127.1°)
Direction and speed of movement W 20km/h(11kt)
Central pressure 950hPa
Maximum wind speed near the center 45m/s(85kt)
Maximum wind gust speed 60m/s(120kt)
Radius of probability circle 390km(210NM)
Storm warning area ALL480km(260NM)

[Alyono]

cannot understand the intensity forecast. This is still a highly sheared system and the shear is showing no signs of abating.

Perhaps a TS or a minimal typhoon for the Philippines

[euro6208]

oh my...re upgraded back to tropical storm status of 35 knots!

[cycloneye]

15:00z warning by JTWC:

[euro6208]

15:00z warning by JTWC:

Possible Major Typhoon landfall...

[Alyono]

not likely. Their center position is too far west, which is affecting the whole forecast

[dexterlabio]

^JMA position much farther west than JTWC. Where do you think is the center located?

[euro6208]

Rammasun was submitted by Thailand which means God of Thunder.

The name was used twice, 2002 and 2008 for a 110 knots Category 3 and a 135 knots Super Typhoon.

The 2002 one hammered the Ryukyu islands and caused 12 deaths and 100 million dollars (2002) and later made landfall over the koreas. China was affected too and the 2008 one aimlessly drove out to sea southeast of Japan...

2014's Rammasun?

[cycloneye]

15:00z JTWC warning discussion:

WDPN32 PGTW 121500
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 09W (RAMMASUN) WARNING
NR 09//
RMKS//
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
TROPICAL STORM (TS) 09W (RAMMASUN), LOCATED APPROXIMATELY 187 NM
WEST OF ANDERSEN AFB, GUAM, HAS TRACKED WESTWARD AT 15 KNOTS OVER
THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED SATELLITE IMAGERY
(EIR) REVEALS DEEPENING CENTRAL CONVECTION AS THE BROKEN FORMATIVE
BANDING ALONG THE LEADING WESTERN EDGE HAS BECOME MORE PERSISTENT
AND THE LOW LEVEL CIRCULATION CENTER (LLCC) IS BEGINNING TO
CONSOLIDATE. A 121205Z AMSU-B MICROWAVE IMAGE ADDITIONALLY SHOWS
IMPROVED LOW LEVEL STRUCTURE AS IMPROVED BANDING CAN BE OBSERVED
DESPITE AN OVERALL SMALL CONVECTIVE SIGNATURE. UPPER-LEVEL ANALYSIS
REVEALS AN UNCHANGED, MARGINAL ENVIRONMENT CHARACTERIZED BY WEAKLY
DIFFLUENT EASTERLY OUTFLOW AND LOW TO MODERATE (10 TO 15 KNOTS)
VERTICAL WIND SHEAR (VWS). THERE IS LOW CONFIDENCE IN THE INITIAL
POSITION DUE TO THE SOME AMBIGUITY IN THE EIR LOOP WHILE POSITION
FIXES FROM ALL REPORTING AGENCIES REMAIN WIDELY SPREAD. THE CURRENT
INTENSITY HAS BEEN INCREASED TO TROPICAL STORM STRENGTH (35 KNOTS)
BASED ON THE IMPROVED LOW LEVEL STRUCTURE OF THE SYSTEM SEEN IN THE
AFOREMENTIONED SATELLITE IMAGERY AND AS DVORAK INTENSITY ESTIMATES
FROM PGTW AND RJTD HAVE INCREASED TO 35 KNOTS AS WELL. TS 09W
CONTINUES TO TRACK ALONG THE SOUTHERN PERIPHERY OF A DEEP-LAYERED
SUBTROPICAL RIDGE (STR) THAT IS ANCHORED TO THE NORTH OF THE SYSTEM.
3. FORECAST REASONING.
A. THERE IS NO CHANGE TO THE FORECAST TRACK PHILOSOPHY FROM THE
PREVIOUS PROGNOSTIC REASONING BULLETIN.
B. TS 09W IS FORECAST TO TRACK WESTWARD FOR THE NEXT 72 HOURS
ALONG THE SOUTHERN PERIPHERY OF THE ENTRENCHED STR. ENVIRONMENTAL
CONDITIONS WILL REMAIN MARGINAL FOR THE NEXT 36 TO 48 HOURS, LEADING
TO A SLOW INTENSIFICATION PROCESS. NEAR TAU 72, VWS WILL BEGIN TO
DECREASE AND OUTFLOW WILL BEGIN TO IMPROVE ALLOWING FOR INCREASED
INTENSIFICATION AS THE SYSTEM APPROACHES THE SOUTHWESTERN EDGE OF
THE STR.
C. AFTER TAU 72, A MID-LATITUDE TROUGH IS FORECAST TO DIG OVER
EASTERN CHINA, WHICH WILL MODIFY THE STR, LEADING TO A MORE WEST-
NORTHWEST TRACK TOWARDS LUZON. FAVORABLE SEA SURFACE TEMPERATURES IN
THE PHILIPPINE SEA ALONG WITH INCREASED OUTFLOW WILL LEAD TO A
MAXIMUM INTENSITY AS THE SYSTEM APPROACHES LAND, REACHING 95 KNOTS
BEFORE LANDFALL. AFTER LANDFALL, THE TERRAIN OF LUZON WILL
SIGNIFICANTLY WEAKEN THE SYSTEM AS IT MOVES INTO THE SOUTH CHINA
SEA. MODEL GUIDANCE IS IN GOOD AGREEMENT; HOWEVER, DUE TO THE LOW
CONFIDENCE IN THE INITIAL POSITIONING, THE OVERALL CONFIDENCE IN THE
FORECAST REMAINS LOW.//

[euro6208]

THERE IS LOW CONFIDENCE IN THE INITIAL
POSITION DUE TO THE SOME AMBIGUITY IN THE EIR LOOP WHILE POSITION
FIXES FROM ALL REPORTING AGENCIES REMAIN WIDELY SPREAD.

hmm...

Wind shear is expected to decrease after 72 hours which would allow for faster intensification despite the very favorable ocean...

Also there seems to be a bit of dry air to the North and Northwest of Rammasun which could potentially weaken the storm...

[Alyono]

^JMA position much farther west than JTWC. Where do you think is the center located?

east edge of the convection