WPAC: NORU - Low

[Kingarabian]

872 mb peak.

[img]http://i.imgur.com/fIcNi9k.png[img]

Verification time has come (just about), and this didn't exactly pan out...

Looks like it had the peak about a day too early?

[1900hurricane]

I mentioned this a little bit in my most recent blog post, but Noru has actually maintained a cyan ring on the 37 GHz microwave imagery for two days now. Maybe we shouldn't be quite as surprised about the intensification as we are now that the system has settled into a favorable area, but these intensification rates are still absurd.







 https://twitter.com/1900hurricane/status/891740259284910081

[1900hurricane]

872 mb peak.

[img]http://i.imgur.com/fIcNi9k.png[img]

Verification time has come (just about), and this didn't exactly pan out...

Looks like it had the peak about a day too early?

Try twelve hours, although even a non-functioning standard 12 hr analog clock still manages to be correct at two instances in a day.

[NotoSans]

I just did a Dvorak fix using the 1730Z satellite imagery. Instantaneous DT yields a 7.0 based on a WMG eye surrounded by W convective ring. FT was 3.5 (or arguably a 4.0) 24 hours ago so MET yields a 5.0 (or 5.5 if a value of 4.0 was used as the FT 24 hours prior). PT yields a 5.5 (or 6.0 if a value of 5.5 is chosen as the MET). Constraints would need to be broken in order to attain a T7.0, but 6-hour average DT calculated since 1230Z was only 6.58. FT would be 6.5 based on rapid intensification, in good agreement with the ADT estimate.

[NotoSans]

JTWC calling for a 145-knot peak intensity.

[Kingarabian]

I just did a Dvorak fix using the 1730Z satellite imagery. Instantaneous DT yields a 7.0 based on a WMG eye surrounded by W convective ring. FT was 3.5 (or arguably a 4.0) 24 hours ago so MET yields a 5.0 (or 5.5 if a value of 4.0 was used as the FT 24 hours prior). PT yields a 5.5 (or 6.0 if a value of 5.5 is chosen as the MET). Constraints would need to be broken in order to attain a T7.0, but 6-hour average DT calculated since 1230Z was only 6.58. FT would be 6.5 based on rapid intensification, in good agreement with the ADT estimate.

I think it's better the JTWC went bullish because they have no problem underestimating intensity.

[NotoSans]

JMA went with 950mb/85kt at their 18Z advisory, corresponding to a T5.5 on their Koba scale.

[1900hurricane]

Here's some very early morning visible imagery.

[1900hurricane]

JTWC sure is taking a while with their discussion.

[euro6208]

Oooo...Woke up to a Cat 5.

[1900hurricane]

 https://twitter.com/DanLindsey77/status/891768804598050825

[euro6208]

[euro6208]

WDPN31 PGTW 302100
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR SUPER TYPHOON 07W (NORU) WARNING NR
41//
RMKS//
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
SUPER TYPHOON (STY) 07W (NORU), LOCATED APPROXIMATELY 122 NM
SOUTH OF IWO TO, HAS TRACKED WESTWARD AT 05 KNOTS OVER THE PAST SIX
HOURS. STY 07W HAS RAPIDLY INTENSIFIED OVER THE PAST 24 HOURS
INCREASING 80 KNOTS FROM 60 KNOTS TO THE CURRENT INTENSITY OF 140
KNOTS. ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY INDICATES
THAT THE SYSTEM IS ANNULAR WITH A SYMMETRIC RING OF DEEP CONVECTION
SURROUNDING A 15-NM CLEAR EYE AND FAIRLY UNIFORM CLOUD TOP
TEMPERATURES. THE INITIAL INTENSITY IS ASSESSED AT 140 KNOTS BASED
ON A DVORAK INTENSITY ESTIMATE OF T7.0 (140 KNOTS) FROM PGTW.
ENVIRONMENTAL CONDITIONS ARE FAVORABLE WITH RADIAL OUTFLOW, ENHANCED
BY A POLEWARD OUTFLOW CHANNEL INTO THE TUTT AND SUBTROPICAL JET TO
THE EAST-NORTHEAST. ADDITIONALLY, SST VALUES HAVE INCREASED TO 29 TO
30C AS THE SYSTEM TRACKED SOUTH OVER THE PREVIOUS DAY. STY 07W IS
DRIFTING WESTWARD WITHIN A COMPETING STEERING ENVIRONMENT.
3. FORECAST REASONING.
A. NO CHANGE TO THE FORECAST TRACK PHILOSOPHY SINCE THE PREVIOUS
PROGNOSTIC REASONING MESSAGE. HOWEVER, FORECAST INTENSITY VALUES
HAVE INCREASED SIGNIFICANTLY.
B. STY 07W IS FORECAST TO TURN ONTO A NORTHWARD TRACK AFTER TAU
24 AS THE EASTERN SUBTROPICAL RIDGE (STR) STRENGTHENS AND THE
WESTERN STR WEAKENS OVER WESTERN JAPAN. THE EXACT TRACK IS DIFFICULT
TO ASCERTAIN WITH AVAILABLE DYNAMIC MODEL TRACKERS INDICATING A WIDE
SPREAD IN SOLUTIONS AT TAU 72, APPROXIMATELY 300NM. NAVGEM IS THE
WESTERN MOST OUTLIER AND SHOWS A WEST-NORTHWESTWARD TRACK INTO THE
RIDGE SO IS CONSIDERED SUSPECT. THE BULK OF THE NUMERICAL GUIDANCE
IS ACTUALLY IN BETTER AGREEMENT WITH A 100NM SPREAD--GFS HAS TRENDED
WESTWARD AND NOW SHOWS A MORE NORTHWARD TRACK VICE NORTHEASTWARD.
THE INTENSITY FORECAST REMAINS UNCERTAIN IN LIGHT OF THE RECENT
UNEXPECTED AND POORLY FORECAST RAPID INTENSIFICATION PHASE BUT, IN
GENERAL, CONDITIONS APPEAR CONDUCIVE FOR INTENSITIES TO REMAIN
GREATER THAN 120 KNOTS THROUGH TAU 72. THROUGH TAU 72, CONFIDENCE
HAS INCREASED BUT REMAINS LOW DUE TO POOR TO FAIR AGREEMENT AMONGST
THE MODEL VORTEX TRACKERS.
C. AFTER TAU 72, UNCERTAINTY INCREASES WITH A 450NM SPREAD IN
SOLUTIONS. IN GENERAL, THE MODELS HAVE BEGUN TO INDICATE DIFFERING
DEGREES OF A WESTWARD TO NORTHWESTWARD TURN LATE IN THE FORECAST
PERIOD. ANALYSIS OF MODEL FIELDS INDICATE THE STR OVER JAPAN WILL RE-
BUILD IN RESPONSE TO A BUILDING MIDLATITUDE SHORTWAVE RIDGE.
FORECASTS BEYOND TAU 120 ARE HIGHLY UNCERTAIN AND DEEMED TENUOUS AT
THIS TIME. STY 07W IS FORECAST TO WEAKEN AFTER TAU 72 AS IT BEGINS
TO TRACK OVER COOLER SST 26 TO 28C. OVERALL, THERE IS LOW CONFIDENCE
IN THE JTWC FORECAST TRACK, HOWEVER, INTERNATIONAL FORECASTS HAVE
REMAINED CONSISTENT AND IN CLOSE AGREEMENT WITH THE JTWC FORECAST
DESPITE THE COMPLEX STEERING ENVIRONMENT.//
NNNN

[1900hurricane]

Not bad, but the eyewall looks a little broad and without particularly sharp brightness gradients. Perhaps the early stages of a transition closer to something annular?

[Digital-TC-Chaser]

Annular Tropical Cyclone.

[euro6208]

07W NORU 170731 0000 22.8N 140.5E WPAC 130 922

Down to a cat 4.

[doomhaMwx]

SuperTyphoon Noru is the NW Pacific's main attraction right now...

[Digital-TC-Chaser]

12Z EC run has Noru wandering about for another week as a robust Cyclone.
Not uncommon for Annular doughnuts to hold intensity over lower sst's.



https://weather.us/satellite/1409-e-226 ... .html#play
doughnut king.

[NotoSans]

JMA still lagging behind with their intensities. They have a Dvorak estimate of T6.0 and an intensity estimate of 90kt at their latest advisory. I would say a T6.5 would be more reasonable, which corresponds to 100kt on their Koba scale.

[euro6208]

WDPN31 PGTW 310300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR SUPER TYPHOON 07W (NORU) WARNING NR
42//
RMKS//
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
SUPER TYPHOON (STY) 07W (NORU), LOCATED APPROXIMATELY 128 NM
SOUTH-SOUTHWEST OF IWO TO, HAS TRACKED WESTWARD AT 04 KNOTS OVER THE
PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY DEPICTS AN
ANNULAR SYSTEM WITH A SYMMETRIC RING OF DEEP CONVECTION SURROUNDING
A 17-NM CLEAR EYE AND FAIRLY UNIFORM CLOUD TOP TEMPERATURES. THE
INITIAL INTENSITY IS ASSESSED AT 130 KNOTS BASED ON DVORAK INTENSITY
ESTIMATES OF T6.5 (127 KNOTS) FROM PGTW AND KNES. ENVIRONMENTAL
CONDITIONS ARE FAVORABLE WITH RADIAL OUTFLOW, ENHANCED BY A POLEWARD
OUTFLOW CHANNEL INTO THE TUTT AND SUBTROPICAL JET TO THE EAST-
NORTHEAST. ADDITIONALLY, SST VALUES HAVE INCREASED TO 29 TO
30C AS THE SYSTEM TRACKED SOUTH OVER THE PREVIOUS DAY. STY 07W IS
DRIFTING WESTWARD WITHIN A COMPETING STEERING ENVIRONMENT.
3. FORECAST REASONING.
A. NO CHANGE TO THE FORECAST TRACK PHILOSOPHY SINCE THE PREVIOUS
PROGNOSTIC REASONING MESSAGE. HOWEVER, FORECAST INTENSITY VALUES
HAVE INCREASED SIGNIFICANTLY.
B. STY 07W IS FORECAST TO TURN ONTO A NORTHWARD TRACK AFTER TAU
24 AS THE EASTERN SUBTROPICAL RIDGE (STR) STRENGTHENS AND THE
WESTERN STR WEAKENS OVER WESTERN JAPAN. THE EXACT TRACK IS DIFFICULT
TO ASCERTAIN WITH AVAILABLE DYNAMIC MODEL TRACKERS INDICATING A WIDE
SPREAD IN SOLUTIONS AT TAU 72, APPROXIMATELY 300NM. NAVGEM AND
COAMPS-TC ARE THE WESTERN MOST OUTLIERS AND SHOW A NORTHWESTWARD
TRACK INTO THE RIDGE SO ARE CONSIDERED SUSPECT. THE BULK OF THE
NUMERICAL GUIDANCE IS ACTUALLY IN BETTER AGREEMENT WITH A 90NM
SPREAD--GFS HAS TRENDED WESTWARD AND NOW SHOWS A MORE NORTHWARD
TRACK VICE NORTH-NORTHEASTWARD. THE INTENSITY FORECAST REMAINS
UNCERTAIN IN LIGHT OF THE RECENT UNEXPECTED AND POORLY FORECAST
RAPID INTENSIFICATION PHASE BUT, IN GENERAL, CONDITIONS APPEAR
CONDUCIVE FOR INTENSITIES TO REMAIN GREATER THAN 110 KNOTS THROUGH
TAU 72. THROUGH TAU 72, CONFIDENCE HAS INCREASED BUT REMAINS LOW DUE
TO POOR TO FAIR AGREEMENT AMONGST THE MODEL VORTEX TRACKERS.
C. AFTER TAU 72, UNCERTAINTY INCREASES WITH A 425NM SPREAD IN
SOLUTIONS AT TAU 120. IN GENERAL, THE MODELS HAVE BEGUN TO INDICATE
DIFFERING DEGREES OF A WESTWARD TO NORTHWESTWARD TURN LATE IN THE
FORECAST PERIOD. ANALYSIS OF MODEL FIELDS INDICATE THE STR OVER
JAPAN WILL RE-BUILD IN RESPONSE TO A BUILDING MIDLATITUDE SHORTWAVE
RIDGE--THIS SHOULD PRODUCE A NORTHWESTWARD TURN AS THE SYSTEM SLOWS
AND COMES UNDER THE STEERING INFLUENCE OF THE RIDGE OVER WESTERN
JAPAN. FORECASTS BEYOND TAU 120 ARE HIGHLY UNCERTAIN AND DEEMED
TENUOUS AT THIS TIME. STY 07W IS FORECAST TO WEAKEN AFTER TAU 72 AS
IT BEGINS TO TRACK OVER COOLER SST 27 TO 28C. OVERALL, THERE IS LOW
CONFIDENCE IN THE JTWC FORECAST TRACK, HOWEVER, INTERNATIONAL
FORECASTS HAVE REMAINED CONSISTENT AND IN CLOSE AGREEMENT WITH THE
JTWC FORECAST DESPITE THE COMPLEX STEERING ENVIRONMENT.//
NNNN