WPAC: RAMMASUN - Post-Tropical

[Alyono]

I know I'm ripping JTWC... but some of the mistakes being made are just bizarre. I'd trust many posters here before JT as I know they wouldn't miss some of the things being missed

[CrazyC83]

I'd say the landfall intensity was 110 kt. Perhaps land interaction kept it from reaching the Dvorak estimates as fast...

[euro6208]

WOW! up to 110 knots per the latest best track!

likely this represents the landfalling intensity which i believe Rammasun made landfall with...

[Alyono]

weakening now based upon the latest imagery. As expected as this moves over land. Real intensity is now probably in the 85-90 kt range.

The bad news is it is starting to turn WNW... aiming for Manila. I'd expect gusts to 90 mph in the center of the city

[euro6208]

Latest best track has winds up to 110 knots which i believe was the landfalling intensity had it come out sooner before landfall but rammasun has now weaken due to land interaction probrably down to 85 to 90 knots when the 18Z update comes out later...

[CrazyC83]

Yeah I think Cat 1 conditions in Manila seem reasonable. That is still scary for a major metropolitan area...

[dexterlabio]

I'd say the landfall intensity was 110 kt. Perhaps land interaction kept it from reaching the Dvorak estimates as fast...

I was going for 115 kts but I doubt there will ever be a report from a reliable station to support this intensity. It looks like an intense Category 3 typhoon when it first hit Albay province.

The arrival of the eye in Albay was covered by the local media, and IMO it's nothing like a Cat1-2 typhoon footage. Almost the same scene when Xangxane hit the Philippines in 2006.

[dexterlabio]

weakening now based upon the latest imagery. As expected as this moves over land. Real intensity is now probably in the 85-90 kt range.

The bad news is it is starting to turn WNW... aiming for Manila. I'd expect gusts to 90 mph in the center of the city

Moving more WNW is a bit of good news IMO, it will track along the mountainous area of Quezon province and Camarines...it will spend more time weakening over rugged terrain before touchdown in Manila..


Haaa, I'm just hoping the electric lines and posts around Manila are better now than the time of Xangxane...

[Alyono]

I'd say the landfall intensity was 110 kt. Perhaps land interaction kept it from reaching the Dvorak estimates as fast...

I was going for 115 kts but I doubt there will ever be a report from a reliable station to support this intensity. It looks like an intense Category 3 typhoon when it first hit Albay province.

The arrival of the eye in Albay was covered by the local media, and IMO it's nothing like a Cat1-2 typhoon footage. Almost the same scene when Xangxane hit the Philippines in 2006.

Here is the issue with using media reports to judge intensity

The media almost certainly did not record the worst of Xangxane. Many media reports from a cat 4 only have TS winds.

Being in an upper cat 2 is the same as being in a low end EF3 tornado due to the gusts. Those winds will destroy most structures. It is just that few actually experience the strongest winds

[dexterlabio]

Here is the issue with using media reports to judge intensity

The media almost certainly did not record the worst of Xangxane. Many media reports from a cat 4 only have TS winds.

Being in an upper cat 2 is the same as being in a low end EF3 tornado due to the gusts. Those winds will destroy most structures. It is just that few actually experience the strongest winds

I was comparing the scene of Xangxane that I personally witnessed here in Manila, to the media footage of Rammasun in Albay this afternoon....granted though, Xangxane weakened to a Cat3 then...

I also got your point, a strong Cat2 is savage enough. My question though is what difference it will make if the eye passes just north or south of Metro Manila?

[cycloneye]

[Alyono]

if it passes just north of Manila, Manila would be on the weaker side of the storm. Could see a difference of about 15 kts in wind speed if it passes north vs south

[euro6208]

Latest discussion...

WDPN32 PGTW 151500
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 09W (RAMMASUN) WARNING NR 21//
RMKS//
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
TYPHOON (TY) 09W (RAMMASUN), LOCATED APPROXIMATELY 152 NM EAST-
SOUTHEAST OF MANILA, PHILIPPINES, HAS TRACKED WEST-NORTHWESTWARD
AT 14 KNOTS OVER THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED
(EIR) SATELLITE IMAGERY DEPICTS A WELL-STRUCTURED SYSTEM AS TY 09W
MOVES OVER LAND. THE CURRENT POSITION IS BASED ON A HIGH CONFIDENCE
SATELLITE EYE FIX ON A CLEAR, 20 NM DIAMETER EYE EVIDENT ON THE EIR
ANIMATION AND 150912Z SSMIS MICROWAVE IMAGERY. THE INITIAL INTENSITY
HAS INCREASED TO 110 KNOTS, SLIGHTLY LOWER THAN CONSISTENT DVORAK
ESTIMATES FROM PGTW, KNES, AND RJTD DUE TO THE CYCLONE BEING ON
LAND. UPPER-LEVEL ANALYSIS CONTINUE TO INDICATE
TY 09W REMAINS IN FAVORABLE ENVIRONMENT WITH LOW (05 TO 10 KNOT)
VERTICAL WIND SHEAR (VWS) AND EXCELLENT POLEWARD AND WESTWARD
OUTFLOW. TY 09W IS CURRENTLY TRACKING WEST-NORTHWESTWARD ALONG THE
SOUTHERN PERIPHERY OF THE SUBTROPICAL RIDGE (STR) TO THE NORTH.
3. FORECAST REASONING.
A. THE INTENSITY FORECAST HAS BEEN INCREASED FOR EVERY POSITION
THROUGH TAU 72 DUE TO THE RAPID INTENSIFICATION OF A WELL-DEFINED
SYSTEM AND AN OVERALL INCREASE IN OBJECTIVE AID INTENSITY GUIDANCE.
B. TY 09W IS FORECAST TO REMAIN ON WEST-NORTHWESTWARD TRACK OVER
THE NEXT 06 HOURS UNDER THE STEERING INFLUENCE OF THE STR. THE
TYPHOON WILL TURN SLIGHTLY MORE POLEWARD BY TAU 12 AS IT
ENCOUNTERS A WEAKNESS IN THE STR INDUCED BY A SHORTWAVE TROUGH
PASSING OVER EASTERN CHINA. TYPHOON RAMMASUN WILL WEAKEN
CONSIDERABLY AS IT TRACKS ACROSS SOUTHERN LUZON AND INTO MANILA OVER
THE NEXT 12 HOURS. HOWEVER, TY 09W IS EXPECTED TO REINTENSIFY AFTER
REEMERGING OVER THE SOUTH CHINA SEA (SCS) TO A CONTINUATION OF THE
AFOREMENTIONED FAVORABLE ENVIRONMENT. WARM SEA SURFACE TEMPERATURES
IN THE SCS AND CONTINUED FAVORABLE UPPER-LEVEL CONDITIONS WILL FAVOR
FURTHER RAPID RE-INTENSIFICATION, PEAKING AT 120 KNOTS PRIOR MAKING
LANDFALL OVER NORTHERN HAINAN ISLAND AROUND TAU 72.
C. IN THE EXTENDED TAUS, THE SYSTEM WILL MAINTAIN A NORTHWESTWARD
TRAJECTORY AS IT CROSSES THE GULF OF TONKIN. LAND INTERACTION WILL
PRIMARILY CAUSE ITS WEAKENING; HOWEVER, TY 09W WILL MAINTAIN TYPHOON
STRENGTH AS IT MAKES THE FINAL LANDFALL INTO NORTHERN VIETNAM NEAR
HANOI. AVAILABLE MODEL GUIDANCE IS IN GOOD AGREEMENT WITH SOME
DIFFERENCES IN TRACK SPEED BUT IS OTHERWISE TIGHTLY GROUPED, LENDING
TO HIGH CONFIDENCE IN THE FORECAST TRACK. HOWEVER, THERE IS STILL
UNCERTAINTY IN THE INTENSITY FORECAST DUE TO THE EXTENT OF THE
WEAKENING ANTICIPATED WITH THE LAND INTERACTION, THEREFORE, THERE IS
OVERALL LOW CONFIDENCE IN THE JTWC FORECAST.//
NNNN

[euro6208]

Euro showing a powerful typhoon for hainan island and vietnam...

The philippines ain't in the clear yet so hoping for this to rapidly weaken and turns out weaker...

[CrazyC83]

I know Legaspi had 966mb as the eyewall passed with 25 kt winds (and those are hourly obs), then 971mb after the flip with 48 kt winds. I would guess 954mb was the minimum pressure as a result, accounting for the obs not being real time and the distance to the eye.

http://www.wunderground.com/history/sta ... story.html

[wxman57]

I'm looking at high-res ECMWF output and see a forecast of 55 to 60 kts for landfall in Hainan. Euro has yet to forecast Rammasun to be a typhoon. It had Rammasun as a 50kt TS at landfall in the Philippines.

[euro6208]

I'm looking at high-res ECMWF output and see a forecast of 55 to 60 kts for landfall in Hainan. Euro has yet to forecast Rammasun to be a typhoon. It had Rammasun as a 50kt TS at landfall in the Philippines.

wow what's wrong with my euro? 50 knots?

[euro6208]

so i guess this 961 mb earlier posted was not from the eye but from the eyewall...

[Alyono]

the 961 could have been from the eye. We had 966 just outside of the eye. Also, a 10 minute wind (likely) not too far from the eye of 51 mph. 10 min wind not that meaningful though as I'm sure strongest winds were not over any area for 10 minutes

[wxman57]

I'm looking at high-res ECMWF output and see a forecast of 55 to 60 kts for landfall in Hainan. Euro has yet to forecast Rammasun to be a typhoon. It had Rammasun as a 50kt TS at landfall in the Philippines.

wow what's wrong with my euro? 50 knots?

It initialized Rammasun at 55kts for 00Z on last night's run - way too low.