WPAC: MERANTI - Post-Tropical

[Cunxi Huang]

AAXX 13181 98132 11460 83418 10268 49830 57000 60301 8657/ 333 56599 86616 88356

983.0 mb doesn't seem right because the Itbayat station was right in the eye and had no equipment failure.
I think it should be 883.0 mb. The number "7" in "57000" means "Decreasing steadily - resultant pressure lower", so the "000" after the "7" may refer to a 100.0 mb pressure decrease compares to 3 hours earlier.
And 1500z SYNOP recorded a pressure of 983 mb thus 1800z would result in a 883 mb pressure.

[Dave C]

I was just watching the radar loop from Taiwan and there appears to be feeder bands still feeding the inner eyewall so this could survive double structure longer than usual. Seems to be stair stepping north and west, at least outer eyewall effects for southern Taiwan.

[Cunxi Huang]

AAXX 13181 98132 11460 83418 10268 49830 57000 60301 8657/ 333 56599 86616 88356

983.0 mb doesn't seem right because the Itbayat station was right in the eye and had no equipment failure.
I think it should be 883.0 mb. The number "7" in "57000" means "Decreasing steadily - resultant pressure lower", so the "000" after the "7" may refer to a 100.0 mb pressure decrease compares to 3 hours earlier.
And 1500z SYNOP recorded a pressure of 983 mb thus 1800z would result in a 883 mb pressure.

in addition, a 35kt (60kph) sustained wind was recorded in the eye, the minimum pressure at 18z could down to 879.5 mb (883-35/10=879.5)

[Dave C]

AAXX 13181 98132 11460 83418 10268 49830 57000 60301 8657/ 333 56599 86616 88356

983.0 mb doesn't seem right because the Itbayat station was right in the eye and had no equipment failure.
I think it should be 883.0 mb. The number "7" in "57000" means "Decreasing steadily - resultant pressure lower", so the "000" after the "7" may refer to a 100.0 mb pressure decrease compares to 3 hours earlier.
And 1500z SYNOP recorded a pressure of 983 mb thus 1800z would result in a 883 mb pressure.

in addition, a 35kt (60kph) sustained wind was recorded, the minimum pressure at 18z could down to 879.5 mb (883-35/10=879.5)

WOW if your correct

[euro6208]

983.0 mb doesn't seem right because the Itbayat station was right in the eye and had no equipment failure.
I think it should be 883.0 mb. The number "7" in "57000" means "Decreasing steadily - resultant pressure lower", so the "000" after the "7" may refer to a 100.0 mb pressure decrease compares to 3 hours earlier.
And 1500z SYNOP recorded a pressure of 983 mb thus 1800z would result in a 883 mb pressure.

in addition, a 35kt (60kph) sustained wind was recorded, the minimum pressure at 18z could down to 879.5 mb (883-35/10=879.5)

WOW if your correct

Very interesting! Hope it verifies...

[mrbagyo]

in addition, a 35kt (60kph) sustained wind was recorded, the minimum pressure at 18z could down to 879.5 mb (883-35/10=879.5)

WOW if your correct

Very interesting! Hope it verifies...

The estimated pressure of 890 hpa is too deep by JMA's standards, but if that reading was correct... 890 hpa would still be an understimation. Wow

"Estimates are sometimes good but correct direct measurements/ observations are always the BEST"

[1900hurricane]

AAXX 13181 98132 11460 83418 10268 49830 57000 60301 8657/ 333 56599 86616 88356

983.0 mb doesn't seem right because the Itbayat station was right in the eye and had no equipment failure.
I think it should be 883.0 mb. The number "7" in "57000" means "Decreasing steadily - resultant pressure lower", so the "000" after the "7" may refer to a 100.0 mb pressure decrease compares to 3 hours earlier.
And 1500z SYNOP recorded a pressure of 983 mb thus 1800z would result in a 883 mb pressure.

Is that the METAR from Weather Underground?

[Cunxi Huang]

AAXX 13181 98132 11460 83418 10268 49830 57000 60301 8657/ 333 56599 86616 88356

983.0 mb doesn't seem right because the Itbayat station was right in the eye and had no equipment failure.
I think it should be 883.0 mb. The number "7" in "57000" means "Decreasing steadily - resultant pressure lower", so the "000" after the "7" may refer to a 100.0 mb pressure decrease compares to 3 hours earlier.
And 1500z SYNOP recorded a pressure of 983 mb thus 1800z would result in a 883 mb pressure.

Is that the METAR from Weather Underground?

i think it's SYNOP format...anyway you can see it on wx underground

[euro6208]

WDPN31 PGTW 132100
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR SUPER TYPHOON 16W (MERANTI) WARNING NR
21//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
SUPER TYPHOON (STY) 16W (MERANTI), LOCATED APPROXIMATELY 259 NM
SOUTH OF TAIPEI, TAIWAN, HAS TRACKED WEST-NORTHWESTWARD AT 09 KNOTS
OVER THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED (EIR) SATELLITE
IMAGERY SHOWS THAT THE SYSTEM HAS CONTINUED TO INTENSITY WITH A DEEP
EXPANSIVE CORE OF CONVECTION SURROUNDING A SHARP 15NM EYE. THE
TAIWAN RADAR LOOP AND A SERIES OF MICROWAVE IMAGES SHOW A VERY
INTENSE CONVECTIVE RING SURROUNDING THE EYE FEATURE WHICH SUPPORTS
THE CURRENT POSITION WITH HIGH CONFIDENCE. THE 131650Z AMSR-2 91GHZ
MICROWAVE IMAGE REVEALS THAT THE CYCLONE IS BEGINNING TO UNDERGO AN
EYEWALL REPLACEMENT CYCLE WITH A SECOND CONVECTIVE RING ALMOST
COMPLETELY SURROUNDING THE INNER RING. THE EIR AND THE RADAR LOOPS
BOTH DEPICT TROCHOIDAL EYE MOTION WHICH MAY IMPACT THE CPA TO
TAIWAN AS IT PASSES TO THE SOUTH. THE INITIAL INTENSITY IS BASED ON
AN ASSESSMENT OF CURRENT INTENSITY ESTIMATES FROM RJTD AND PGTW AS
WELL AS A SATCON INTENSITY ESTIMATE ABOVE 170 KNOTS. STY 16W
MAINTAINS A VERY FAVORABLE ENVIRONMENT WITH LOW VERTICAL WIND SHEAR
(VWS), STRONG RADIAL OUTFLOW, AND VERY WARM SEA SURFACE
TEMPERATURES. HOWEVER, BETWEEN THE LAND INTERACTION WITH TAIWAN AND
THE IMPENDING EYEWALL REPLACEMENT CYCLE, THE SYSTEM HAS REACHED ITS
PEAK INTENSITY. STY 16W IS UNDER THE STEERING INFLUENCE OF A
SUBTROPICAL RIDGE (STR) TO THE NORTH.
3. FORECAST REASONING.
A. NO CHANGE IN THE FORECAST PHILOSOPHY SINCE THE PREVIOUS
PROGNOSTIC REASONING MESSAGE.
B. STY 16W WILL TRACK GENERALLY WEST-NORTHWESTWARD THROUGHOUT THE
FORECAST UNDER THE STEERING INFLUENCE OF THE STR. THE COMBINED
EFFECTS OF INCREASING VWS, LAND INTERACTION, AND THE EYEWALL
REPLACEMENT CYCLE WILL ALL SERVE TO WEAKEN THE SYSTEM AS IT
APPROACHES CHINA. JUST AFTER TAU 24, STY MERANTI WILL MAKE LANDFALL
IN CHINA AS A STRONG TYPHOON. THE RUGGED TERRAIN AND INCREASED VWS
WILL RAPIDLY ERODE THE SYSTEM, DISSIPATING IT AS A SIGNIFICANT
CYCLONE OVER LAND BY TAU 48. DYNAMIC MODEL GUIDANCE REMAINS IN GOOD
AGREEMENT, LENDING HIGH CONFIDENCE IN THE JTWC TRACK FORECAST UP TO
LANDFALL IN CHINA WHERE TRACK VARIABILITY IS HIGH DUE TO THE
FORECASTED RAPID DISSIPATION.//
NNNN

[1900hurricane]

Looks like eyewall replacement and Taiwan reaction is beginning to take its toll on Meranti.

[1900hurricane]

983.0 mb doesn't seem right because the Itbayat station was right in the eye and had no equipment failure.
I think it should be 883.0 mb. The number "7" in "57000" means "Decreasing steadily - resultant pressure lower", so the "000" after the "7" may refer to a 100.0 mb pressure decrease compares to 3 hours earlier.
And 1500z SYNOP recorded a pressure of 983 mb thus 1800z would result in a 883 mb pressure.

Is that the METAR from Weather Underground?

i think it's SYNOP format...anyway you can see it on wx underground

Oops, yeah you're right, definitely not METAR.

Anyway, we're looking at the same thing then, which is what I wanted to know. Cool!

https://www.wunderground.com/history/station/98132/2016/9/14/DailyHistory.html?MR=1

[euro6208]

Meranti is now tied with obsolete Tip for 2nd strongest winds on record.

Of course Haiyan was likely stronger as well as Megi and storms after 1987 might very well be underestimated.

[Alyono]

that's nowhere close to 165 kts now. Looks to be weakening quickly as it undergoes the EWRC

[1900hurricane]

Morning vis is a bit frumpy.

[1900hurricane]

Even without Taiwan complicating things, this eyewall replacement looks like it would take a while.

[1900hurricane]

It looks to me that the mountains of Taiwan are dinging up Meranti way more than eyewall replacement is. Even with a 165 kt starting point, I'd drop down to at least 145 kt.

[euro6208]

[1900hurricane]

The outer eyewall has lost a lot of definition.

[dexterlabio]

The 120mph sustained winds (10-min ave) recorded in Basco Batanes support at least Cat4 condition in that area, aren't they? If so, then Itbayat surely had sustained Cat5 winds when the eye hit the island. Basco is a few kilometers south of Itbayat.

[NotoSans]

Seems to be weakening significantly as it interacts with the rugged terrains in Taiwan. I would go with 140 kt right now, but the intensity could be a little bit higher.