WPAC: NURI - Post-Tropical

[euro6208]

897 mb? Is that some kind of record for a post cyclone?

[somethingfunny]

:uarrow:

897 mb? Is that some kind of record for a post cyclone?

If it verified I believe it would be a record, but I don't know what the records are - I just know that I can't comprehend an extratropical cyclone that strong.

It's just one GFS ensemble member of course, but even the operational ECMWF is depicting 914mb.

[euro6208]

125 knots...

WDPN31 PGTW 040900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 20W (NURI) WARNING NR 18//
RMKS//
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
TYPHOON (TY) 20W (NURI), LOCATED APPROXIMATELY 358 NM WEST-
SOUTHWEST OF IWO TO, HAS TRACKED NORTH-NORTHEASTWARD AT 09 KNOTS
OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY,
ALONG WITH A 040402Z AMSU-B PARTIAL MICROWAVE PASS REVEALS THAT TY
NURI APPEARS TO BE COMPLETING THE PREVIOUSLY OBSERVED EYEWALL
REPLACEMENT CYCLE AS THE CORE CONVECTION HAS BECOME MORE SYMMETRIC
AND COMPACT AROUND THE SMALL 10 NM EYE FEATURE. THERE IS HIGH
CONFIDENCE IN THE CURRENT POSITION AND MOTION OF THE SYSTEM DUE TO
THIS WELL DEFINED EYE FEATURE. THE INITIAL INTENSITY HAS BEEN
SLIGHTLY DECREASED TO 125 KNOTS BASED ON AN ASSESSMENT OF DVORAK
INTENSITY ESTIMATES THAT RANGE FROM 115 TO 127 KNOTS AND THE
STRUCTURE OF THE SYSTEM WHILE THE CURRENT WINDFIELD HAS BEEN
INCREASED USING A 040118Z ASCAT PASS. UPPER LEVEL ANALYSIS REVEALS
AN OVERALL FAVORABLE ENVIRONMENT AS VIGOROUS POLEWARD OUTFLOW INTO A
JET MAX LOCATED TO THE NORTHEAST OF THE SYSTEM OFFSETS INCREASING
WESTERLY VERTICAL WIND SHEAR (VWS) WHICH IS NOW ASSESSED AT MODERATE
LEVELS (15 TO 25 KNOTS). TY 20W IS CURRENTLY TRACKING NORTHEAST
AROUND THE WESTERN PERIPHERY OF THE SUBTROPICAL RIDGE LOCATED TO THE
EAST OF THE SYSTEM.
3. FORECAST REASONING.
A. NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS
PROGNOSTIC REASONING MESSAGE.
B. TY 20W WILL CONTINUE TRACKING GENERALLY NORTHEASTWARD OVER THE
NEXT 36 TO 48 HOURS AS IT ROUNDS THE PERIPHERY OF THE CURRENT
STEERING RIDGE WHILE FURTHER INCREASING WESTERLY VWS AND DECREASING
ALONG-TRACK OCEAN HEAT CONTENT ARE EXPECTED TO INDUCE A STEADY
WEAKENING TREND. NEAR TAU 48, TY 20W WILL ROUND THE STEERING RIDGE
AND ENCOUNTER A BAROCLINIC ZONE AHEAD OF A DEVELOPING MID-LATITUDE
TROUGH THAT IS EXPECTED TO BE DIGGING ACROSS THE SEA OF JAPAN. THIS
WILL ACCELERATE THE SYSTEM MORE EASTWARD AS IT RAPIDLY TRANSITIONS
INTO A VERY STRONG EXTRATROPICAL LOW AS IT PASSES WELL TO THE EAST
OF MAINLAND JAPAN BETWEEN TAUS 48 AND 72. NUMERICAL MODEL GUIDANCE
CONTINUES TO SHOW SOME SLIGHT DISAGREEMENT IN REGARDS TO THE
TRANSLATIONAL SPEED OF SYSTEM AS IT PROCEEDS TO THE NORTHEAST.
HOWEVER, THE CONSENSUS MEMBERS REMAIN IN A TIGHT GROUPING IN REGARDS
TO TRACK. DUE TO THIS, HIGH CONFIDENCE REMAINS IN THE OVERALL TRACK
WHICH IS POSITIONED CLOSE TO MULTI-MODEL CONSENSUS IN THE EARLY
FORECAST AND SLIGHTLY FASTER THAN IN THE EXTENDED FORECAST TO OFFSET
THE SLOWER GUIDANCE AS THE SYSTEM BECOMES EMBEDDED IN THE MID-
LATITUDE WESTERLIES.//
NNNN

[xtyphooncyclonex]

20W NURI 141104 1200 23.1N 136.3E WPAC 120 933

[euro6208]

WDPN31 PGTW 041500
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 20W (NURI) WARNING NR 19//
RMKS//
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
TYPHOON (TY) 20W (NURI), LOCATED APPROXIMATELY 293 NM WEST-
SOUTHWEST OF IWO TO, HAS TRACKED NORTHEASTWARD AT 12 KNOTS OVER THE
PAST SIX HOURS. ANIMATED ENHANCED INFRARED SATELLITE IMAGERY, ALONG
WITH A 040925Z TRMM MICROWAVE IMAGE REVEALS THAT TY NURI CONTINUES
TO BE UNDERGOING AN EYEWALL REPLACEMENT CYCLE ALTHOUGH THE
PREVIOUSLY OBSERVED EYE FEATURE HAS BECOME CLOUD FILLED AND LESS
DEFINED. THERE IS HIGH CONFIDENCE IN THE CURRENT POSITION AND MOTION
OF THE SYSTEM BASED ON PERSISTENCE FROM THE PREVIOUSLY OBSERVED EYE
FEATURE. THE INITIAL INTENSITY HAS BEEN SLIGHTLY DECREASED TO 120
KNOTS BASED ON AN ASSESSMENT OF DVORAK INTENSITY ESTIMATES THAT
RANGE FROM 115 TO 127 KNOTS AND THE WEAKENED STRUCTURE OF THE SYSTEM
OBSERVED IN THE AFOREMENTIONED IMAGERY. UPPER LEVEL ANALYSIS REVEALS
AN OVERALL FAVORABLE ENVIRONMENT AS VIGOROUS POLEWARD OUTFLOW INTO A
JET MAX LOCATED TO THE NORTHEAST OF THE SYSTEM OFFSETS INCREASING
WESTERLY VERTICAL WIND SHEAR (VWS) WHICH IS ASSESSED AT MODERATE
LEVELS (15 TO 25 KNOTS). TY 20W IS CURRENTLY TRACKING NORTHEAST
AROUND THE WESTERN PERIPHERY OF THE SUBTROPICAL RIDGE LOCATED TO THE
EAST OF THE SYSTEM.
3. FORECAST REASONING.
A. NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS
PROGNOSTIC REASONING MESSAGE.
B. TY 20W WILL CONTINUE TRACKING GENERALLY NORTHEASTWARD OVER THE
NEXT 36 TO 48 HOURS AS IT TRACKS AROUND THE PERIPHERY OF THE CURRENT
STEERING RIDGE WHILE FURTHER INCREASING WESTERLY VWS AND DECREASING
ALONG-TRACK OCEAN HEAT CONTENT ARE EXPECTED TO INDUCE A STEADY
WEAKENING TREND. NEAR TAU 48, TY 20W WILL ROUND THE STEERING RIDGE
AND ENCOUNTER A BAROCLINIC ZONE AHEAD OF A DEVELOPING MID-LATITUDE
TROUGH THAT IS EXPECTED TO BE DIGGING ACROSS THE SEA OF JAPAN. THIS
WILL ACCELERATE THE SYSTEM MORE EAST-NORTHEASTWARD AS IT RAPIDLY
TRANSITIONS INTO A STRONG EXTRATROPICAL LOW AS IT PASSES WELL TO THE
EAST OF THE JAPANESE MAINLAND BETWEEN TAUS 48 AND 72. NUMERICAL
MODEL GUIDANCE CONTINUES TO SHOW SOME SLIGHT DISAGREEMENT IN REGARDS
TO THE TRANSLATIONAL SPEED OF SYSTEM AS IT PROCEEDS TO THE
NORTHEAST. HOWEVER, THE CONSENSUS MEMBERS REMAIN IN A TIGHT GROUPING
IN REGARDS TO TRACK. DUE TO THIS, HIGH CONFIDENCE REMAINS IN THE
OVERALL TRACK WHICH IS POSITIONED CLOSE TO MULTI-MODEL CONSENSUS IN
THE EARLY FORECAST AND SLIGHTLY FASTER THAN IN THE EXTENDED FORECAST
TO OFFSET THE SLOWER GUIDANCE AS THE SYSTEM BECOMES EMBEDDED IN THE
MID-LATITUDE WESTERLIES.//
NNNN

[mrbagyo]

20W NURI 141104 1800 24.0N 136.9E WPAC 105 944

[RL3AO]

Very excited to track the downstream impacts of Nuri over North America next week.

[euro6208]

WDPN31 PGTW 050300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 20W (NURI) WARNING NR 21//
RMKS//
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
TYPHOON (TY) 20W (NURI), LOCATED APPROXIMATELY 213 NM WEST OF IWO
TO, HAS TRACKED NORTHEASTWARD AT 10 KNOTS OVER THE PAST SIX HOURS.
ANIMATED MULTISPECTRAL SATELLITE IMAGERY DEPICTS A SLIGHT WEAKENING
TREND; HOWEVER, THE SYSTEM HAS RETAINED TIGHTLY-CURVED BANDING (TCB)
WRAPPING INTO A WELL-DEFINED LOW-LEVEL CIRCULATION CENTER. A 050055Z
METOP-B 89GHZ IMAGE DEPICTS ORGANIZED, SYMMETRIC CORE CONVECTION
WITH TCB WRAPPING INTO THE CENTER. THE INITIAL INTENSITY IS ASSESSED
AT 100 KNOTS BASED ON DVORAK CURRENT INTENSITY ESTIMATES RANGING
FROM 90 TO 102 KNOTS. UPPER-LEVEL ANALYSIS REVEALS A FAVORABLE
ENVIRONMENT DUE TO VIGOROUS POLEWARD OUTFLOW INTO THE MIDLATITUDE
WESTERLIES, WHICH IS OFFSETTING MODERATE VERTICAL WIND SHEAR (VWS).
TY 20W IS CURRENTLY TRACKING POLEWARD AROUND THE NORTHWESTERN
PERIPHERY OF THE SUBTROPICAL RIDGE.
3. FORECAST REASONING.
A. NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS
PROGNOSTIC REASONING MESSAGE.
B. TY 20W IS FORECAST TO ACCELERATE NORTHEASTWARD AS IT TRACKS
POLEWARD OF THE SUBTROPICAL RIDGE AXIS, AND INTO THE STRONG
MIDLATITUDE WESTERLIES. NEAR TAU 12, TY NURI SHOULD BEGIN EXTRA-
TROPICAL TRANSITION (ETT) AS IT INTERACTS WITH THE BAROCLINIC ZONE.
TY 20W SHOULD COMPLETE ETT BY TAU 48 AS IT BECOMES EMBEDDED IN THE
MIDLATITUDE WESTERLIES AND GAINS FRONTAL CHARACTERISTICS. DYNAMIC
MODEL GUIDANCE IS IN TIGHT AGREEMENT, THEREFORE, THERE IS HIGH
CONFIDENCE IN THE JTWC FORECAST TRACK, WHICH IS POSITIONED SLIGHTLY
FASTER THAN THE MULTI-MODEL CONSENSUS. TY 20W IS FORECAST TO WEAKEN
RAPIDLY AFTER TAU 12 DUE TO STRONG VWS AND INTERACTION WITH THE
BAROCLINIC ZONE.//
NNNN

[euro6208]

WDPN31 PGTW 051500
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 20W (NURI) WARNING NR 23//
RMKS//
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
TYPHOON (TY) 20W (NURI), LOCATED APPROXIMATELY 174 NM NORTHWEST
OF IWO TO, HAS TRACKED NORTHEASTWARD AT 10 KNOTS OVER THE PAST SIX
HOURS. ANIMATED ENHANCED INFRARED SATELLITE IMAGERY SHOWS THAT TY
NURI CONTINUES TO WEAKEN AS DEEP CONVECTION HAS FURTHER DIMINISHED
AS THE BANDING FEATURES HAVE WEAKENED AND THE LOW-LEVEL CIRCULATION
CENTER (LLCC) HAS BECOME LESS DEFINED. A 051002Z TRMM MICROWAVE
IMAGE ADDITIONALLY REVEALS THE LLCC IS BEGINNING TO UNRAVEL AS THE
DEEP CONVECTION HAS BECOME ISOLATED TO THE NORTHERN SEMI-CIRCLE
ALTHOUGH A WEAK MICROWAVE EYE FEATURE REMAINS PRESENT. THE INITIAL
POSITION AND MOTION OF THE SYSTEM IS BASED UPON PERSISTENCE FROM
THIS MICROWAVE EYE FEATURE WITH GOOD CONFIDENCE. THE INITIAL
INTENSITY HAS BEEN DECREASED TO 80 KNOTS BASED ON DVORAK INTENSITY
ESTIMATES THAT RANGE FROM 77 TO 90 KNOTS AND IS ADDITIONALLY
SUPPORTED BY THE DECREASING STRUCTURE OF THE SYSTEM OBSERVED IN THE
AFOREMENTIONED IMAGERY. UPPER-LEVEL ANALYSIS REVEALS A DECREASING
ENVIRONMENT AS VIGOROUS POLEWARD OUTFLOW INTO THE MIDLATITUDE
WESTERLIES IS NOW ONLY PARTIALLY OFFSETTING THE INCREASING VERTICAL
WIND SHEAR (VWS) WHICH IS ASSESSED AT MODERATE TO STRONG LEVELS (20
TO 30 KNOTS). TY 20W IS CURRENTLY TRACKING POLEWARD AROUND THE
NORTHWESTERN PERIPHERY OF THE SUBTROPICAL RIDGE.
3. FORECAST REASONING.
A. NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS
PROGNOSTIC REASONING MESSAGE.
B. TY 20W IS FORECAST TO ACCELERATE NORTHEASTWARD AS IT TRACKS
ALONG THE PERIPHERY OF THE SUBTROPICAL RIDGE AND INTO THE STRONG
MIDLATITUDE WESTERLIES WHICH WILL CONTINUE THE STEADY WEAKENING
TREND OF THE SYSTEM. NEAR TAU 12, TY 20W WILL BEGIN EXTRA-TROPICAL
TRANSITION (ETT) AS IT INTERACTS WITH THE BAROCLINIC ZONE AND SHOULD
COMPLETE ETT BY TAU 36 AS IT BECOMES EMBEDDED IN THE MIDLATITUDE
WESTERLIES AND GAINS FRONTAL CHARACTERISTICS. DYNAMIC MODEL GUIDANCE
IS IN TIGHT AGREEMENT, THEREFORE, THERE IS HIGH CONFIDENCE IN THE
JTWC FORECAST TRACK, WHICH IS POSITIONED SLIGHTLY FASTER THAN THE
MULTI-MODEL CONSENSUS.//
NNNN

[euro6208]

20W NURI 141105 1800 27.3N 139.6E WPAC 75 967

Down to 75 knots...

[euro6208]

WTPN31 PGTW 060300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE WARNING//
RMKS/
1. TROPICAL STORM 20W (NURI) WARNING NR 025
DOWNGRADED FROM TYPHOON 20W
01 ACTIVE TROPICAL CYCLONE IN NORTHWESTPAC
MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
WIND RADII VALID OVER OPEN WATER ONLY
---
WARNING POSITION:
060000Z --- NEAR 28.2N 140.1E
MOVEMENT PAST SIX HOURS - 035 DEGREES AT 12 KTS
POSITION ACCURATE TO WITHIN 060 NM
POSITION BASED ON CENTER LOCATED BY SATELLITE
PRESENT WIND DISTRIBUTION:
MAX SUSTAINED WINDS - 055 KT, GUSTS 070 KT
WIND RADII VALID OVER OPEN WATER ONLY
BECOMING EXTRATROPICAL
RADIUS OF 050 KT WINDS - 075 NM NORTHEAST QUADRANT
065 NM SOUTHEAST QUADRANT
000 NM SOUTHWEST QUADRANT
000 NM NORTHWEST QUADRANT
RADIUS OF 034 KT WINDS - 125 NM NORTHEAST QUADRANT
125 NM SOUTHEAST QUADRANT
085 NM SOUTHWEST QUADRANT
065 NM NORTHWEST QUADRANT
REPEAT POSIT: 28.2N 140.1E
---
FORECASTS:
12 HRS, VALID AT:
061200Z --- 32.2N 143.8E
MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT
WIND RADII VALID OVER OPEN WATER ONLY
EXTRATROPICAL
VECTOR TO 24 HR POSIT: 045 DEG/ 42 KTS
---
24 HRS, VALID AT:
070000Z --- 37.9N 151.3E
MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT
WIND RADII VALID OVER OPEN WATER ONLY
EXTRATROPICAL
---
REMARKS:
060300Z POSITION NEAR 29.2N 141.0E.
TROPICAL STORM (TS) 20W (NURI), LOCATED APPROXIMATELY 130 NM WEST-
NORTHWEST OF CHICHI JIMA, HAS TRACKED NORTHEASTWARD AT 12 KNOTS
OVER THE PAST SIX HOURS. TS 20W HAS NEARLY COMPLETED EXTRA-TROPICAL
TRANSITION, WITH CLEAR FRONTAL CHARACTERISTICS IN MULTI-SPECTRAL
SATELLITE IMAGERY. MODELS INDICATE THE SYSTEM WILL BE FULLY ABSORBED
INTO THE BAROCLINIC ZONE BY TAU 6. THIS SYSTEM IS EXPECTED TO BE A
STRONG EXTRA-TROPICAL LOW GIVEN THE GOOD UPPER LEVEL JET SUPPORT.
THIS IS THE FINAL WARNING ON THIS SYSTEM BY THE JOINT TYPHOON
WRNCEN PEARL HARBOR HI. THE SYSTEM WILL BE CLOSELY MONITORED FOR
SIGNS OF REGENERATION. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 060000Z
IS 25 FEET.//
NNNN

[euro6208]

There goes our once monster category 5...

Thanks to Nuri, season ACE is up to 238.743

Total ACE for nuri, 26.9675...

[RL3AO]

We've just hit the midpoint for Nuri's show. Its about to start something very amazing. Could become the strongest extratropical storm ever recorded in the North Pacific.

[somethingfunny]

I don't suppose NOAA has the presence of mind/finance/organization to send a reconnaissance plane/drone into this extratropical monster, do they?

[talkon]

Nuri is now a 924 mb extratropical cyclone, a record low for the NPAC

WWJP25 RJTD 080000
WARNING AND SUMMARY 080000.
WARNING VALID 090000.
WARNING IS UPDATED EVERY 6 HOURS.
STORM WARNING.
DEVELOPING LOW 924 HPA
AT 55N 169E SEA EAST OF KAMCHATKA MOVING NORTHNORTHEAST 25 KNOTS.
OCCLUDED FRONT FROM 55N 169E TO 54N 178E 50N 178W.
WARM FRONT FROM 50N 178W TO 45N 175W 40N 176W.
COLD FRONT FROM 50N 178W TO 44N 180E 37N 170E 31N 158E.
WINDS 30 TO 70 KNOTS WITHIN 1100 MILES OF LOW SOUTH SEMICIRCLE AND
900 MILES ELSEWHERE.
FORECAST POSITION FOR 090000UTC AT 55N 174E WITH UNCERTAINTY OF 85
MILES RADIUS.
WARNING.
DENSE FOG OBSERVED LOCALLY OVER WATERS BOUNDED BY 55N 169E 60N 163E
60N 180E 53N 180E 55N 169E.
SUMMARY.
LOW PRESSURE AREA 1010 HPA NEAR 06N 103E WEST SLOWLY.
LOW PRESSURE AREA 1010 HPA NEAR 09N 145E WNW SLOWLY.
HIGH 1030 HPA AT 38N 138E EAST 20 KT.
JAPAN METEOROLOGICAL AGENCY.=

[mrbagyo]

Bring it down even more... now @ 920 mb as per JMA

EMERGENCY WARNING 080300.
WARNING VALID 090300.
STORM WARNING.
DEVELOPING LOW 920 HPA
AT 55N 169E SEA EAST OF KAMCHATKA MOVING NORTH 15 KNOTS.
OCCLUDED FRONT FROM 55N 169E TO 54N 180E 49N 176W.
WARM FRONT FROM 49N 176W TO 45N 174W 41N 175W.
COLD FRONT FROM 49N 176W TO 43N 180E 36N 170E 30N 159E.
WINDS 30 TO 70 KNOTS WITHIN 1200 MILES OF LOW SOUTH SEMICIRCLE AND
900 MILES ELSEWHERE.
FORECAST POSITION FOR 090300UTC AT 54N 177E WITH UNCERTAINTY OF 85
MILES RADIUS.