WPAC: LEKIMA - Post-Tropical

[euro6208]

Category 3 105 knots


WDPN32 PGTW 250900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 28W (LEKIMA) WARNING NR 20//
RMKS//
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
TYPHOON (TY) 28W (LEKIMA), LOCATED APPROXIMATELY 555 NM
SOUTH-SOUTHEAST OF YOKOSUKA, JAPAN, HAS TRACKED NORTHWARD AT 20 KNOTS
OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY
(MSI) SHOWS THE SYSTEM HAS MAINTAINED A 10-NM EYE AS IT BEGUN TO
ACCELERATE POLEWARD. CONCURRENTLY, THE OVERALL STRUCTURE HAS
ELONGATED AS CONVECTION BECAME MORE SHALLOW. THE INITIAL POSITION IS
BASED ON THE EYE FEATURE IN THE MSI ANIMATION WITH HIGH CONFIDENCE.
THE INITIAL INTENSITY OF 105 KNOTS IS AVERAGED FROM VERY CLOSE DVORAK
ESTIMATES FROM PGTW, KNES, AND RJTD. UPPER LEVEL ANALYSIS INDICATES
A POINT SOURCE ANTICYCLONE CONTINUES TO PROVIDE FAVORABLE RADIAL
OUTFLOW. HOWEVER, VERTICAL WIND SHEAR (VWS) HAS INCREASED TO 15-20
KNOTS. THE CYCLONE HAS CRESTED THE WESTERN PERIPHERY OF THE
DEEP-LAYERED SUBTROPICAL RIDGE TO THE EAST AND IS POISED TO
ACCELERATE NORTHEASTWARD.
3. FORECAST REASONING.
A. NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS
PROGNOSTIC REASONING.
B. TY LEKIMA IS EXPECTED TO ACCELERATE NORTHEASTWARD AS IT GETS
EMBEDDED IN THE MID-LATITUDE WESTERLIES. COOLING SEA SURFACE
TEMPERATURES, IN ADDITION TO INCREASING VWS, WILL RAPIDLY ERODE THE
SYSTEM. EXTRA-TROPICAL TRANSITION WILL COMMENCE AROUND TAU 12, WITH
COMPLETE TRANSITION TO A STORM-FORCE COLD-CORE LOW BY TAU 36. DYNAMIC
MODEL GUIDANCE REMAINS IN TIGHT AGREEMENT, LENDING HIGH CONFIDENCE IN
THE JTWC TRACK FORECAST THAT IS LAID JUST TO THE RIGHT OF AND
SLIGHTLY FASTER THAN THE MULTI-MODEL CONSENSUS. THIS STRATEGY IS USED
TO OFFSET KNOWN CLIMATOLOGICAL TRACK TENDENCIES. //
NNNN

[euro6208]

WDPN32 PGTW 251500
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 28W (LEKIMA) WARNING NR 22//
RMKS//
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
TYPHOON (TY) 28W (LEKIMA), LOCATED APPROXIMATELY 444 NM SOUTHEAST
OF YOKOSUKA, JAPAN, HAS TRACKED NORTH-NORTHEASTWARD AT 24 KNOTS OVER
THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED (EIR) SATELLITE
IMAGERY SHOWS THE EYE HAS SHRUNK TO A 04-NM PINHOLE AS THE SYSTEM
ACCELERATED POLEWARD. CONCURRENTLY, THE OVERALL STRUCTURE HAS
ELONGATED AS CONVECTION BECAME MORE SHALLOW. THE INITIAL POSITION IS
BASED ON THE EYE FEATURE IN THE EIR ANIMATION WITH HIGH CONFIDENCE.
THE INITIAL INTENSITY OF 100 KNOTS IS BASED ON THE LOW END OF VERY
CLOSE DVORAK ESTIMATES FROM PGTW, KNES, AND RJTD TO REFLECT THE
WEAKENING TREND. UPPER LEVEL ANALYSIS INDICATES A POINT SOURCE
ANTICYCLONE CONTINUES TO PROVIDE FAVORABLE RADIAL OUTFLOW. HOWEVER,
INCREASING VERTICAL WIND SHEAR (VWS) HAS BEGUN TO IMPACT THE SYSTEM.
THE CYCLONE HAS CRESTED THE WESTERN PERIPHERY OF THE DEEP-LAYERED
SUBTROPICAL RIDGE TO THE EAST AND IS NOW RECURVING NORTHEASTWARD.
3. FORECAST REASONING.
A. NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS
PROGNOSTIC REASONING.
B. TY LEKIMA IS EXPECTED TO CONTINUE ACCELERATING NORTHEASTWARD AS
IT GETS EMBEDDED DEEPER IN THE MID-LATITUDE WESTERLIES. COOLING SEA
SURFACE TEMPERATURES, IN ADDITION TO INCREASING VWS, WILL RAPIDLY
ERODE THE SYSTEM. EXTRA-TROPICAL TRANSITION HAS COMMENCED AND TY 28W
WILL BECOME A STORM-FORCE COLD-CORE LOW BY TAU 24. DYNAMIC MODEL
GUIDANCE REMAINS IN TIGHT AGREEMENT, LENDING HIGH CONFIDENCE IN THE
JTWC TRACK FORECAST THAT IS LAID JUST TO THE RIGHT OF AND SLIGHTLY
FASTER THAN THE MULTI-MODEL CONSENSUS. THIS STRATEGY IS USED TO
OFFSET KNOWN CLIMATOLOGICAL TRACK TENDENCIES. //
NNNN

[euro6208]

WDPN32 PGTW 260300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 28W (LEKIMA) WARNING NR 23//
RMKS//
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
TYPHOON (TY) 28W (LEKIMA), LOCATED APPROXIMATELY 457 NM EAST OF
YOKOSUKA, JAPAN, HAS TRACKED NORTHEASTWARD AT 31 KNOTS OVER THE PAST
SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY DEPICTS A
PARTIALLY-EXPOSED LOW-LEVEL CIRCULATION CENTER POSITIONED ALONG THE
WESTERN EDGE OF THE DEEP CONVECTION, WHICH HAS DECAYED SIGNIFICANTLY
OVER THE PAST SIX HOURS. A 252249Z SSMIS IMAGE ALSO INDICATES A WELL-
ORGANIZED LOW-LEVEL CIRCULATION CENTER WITH DEEP CONVECTIVE BANDING
CONFINED TO THE EASTERN SEMI-CIRCLE. THERE IS GOOD CONFIDENCE IN THE
INITIAL POSITION BASED ON THIS RECENT MICROWAVE IMAGE AS WELL AS THE
VISIBLE IMAGERY. THE INITIAL INTENSITY IS ASSESSED AT 75 KNOTS BASED
ON CURRENT INTENSITY ESTIMATES OF 77 KNOTS FROM PGTW AND KNES. TY 28W
IS TRACKING UNDER STRONG (30 TO 40 KNOTS) WESTERLY VERTICAL WIND
SHEAR (VWS) AND HAS BEGUN EXTRA-TROPICAL TRANSITION (ETT) AS IT BEGINS
TO INTERACT WITH THE MIDLATITUDE WESTERLIES.
3. FORECAST REASONING.
A. NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS
PROGNOSTIC REASONING.
B. TY LEKIMA IS EXPECTED TO WEAKEN QUICKLY OVER THE NEXT 12 HOURS
AS THE SYSTEM ENCOUNTERS INCREASING VWS AND COOLER SST. TY 28W
SHOULD COMPLETE ETT BY TAU 18 AS IT GAINS FRONTAL CHRACTERISTICS.
DYNAMIC MODEL GUIDANCE REMAINS IN TIGHT AGREEMENT, LENDING HIGH
CONFIDENCE IN THE JTWC TRACK FORECAST, WHICH IS POSITIONED JUST TO
THE RIGHT OF AND SLIGHTLY FASTER THAN THE MULTI-MODEL CONSENSUS.
THIS STRATEGY IS USED TO OFFSET KNOWN CLIMATOLOGICAL TRACK
TENDENCIES.//
NNNN

[Grifforzer]

last advisory on Lekima..

** WTPQ21 RJTD 261200 ***
RSMC TROPICAL CYCLONE ADVISORY
NAME DEVELOPED LOW FORMER TY 1328 LEKIMA (1328)
ANALYSIS
PSTN 261200UTC 39N 155E
MOVE NE 35KT
PRES 980HPA
MXWD 055KT
30KT 400NM SOUTHEAST 200NM NORTHWEST =

[Meow]

Based on 10-minute maximum sustained winds from RSMC Tokyo, Lekima (115 knots) was the most intense tropical cyclone in the northwest Pacific Ocean since Megi (125 knots) in 2010.

[xtyphooncyclonex]

Lekima interacted with Francisco's remnants already and is an upper-level low.