WPAC: NORU - Low

[doomhaMwx]

NASA AQUA/MODIS High-Res RGB Imagery
08-03-17 4:43am UTC

[Digital-TC-Chaser]

Mets office forecasting another big ramp up to intense.
http://tgftp.nws.noaa.gov/data/raw/fx/fxxt03.egrr..txt

TYPHOON NORU ANALYSED POSITION : 27.5N 134.8E

VERIFYING TIME POSITION STRENGTH TENDENCY
-------------- -------- -------- --------
00UTC 03.08.2017 27.5N 134.8E STRONG
12UTC 03.08.2017 28.1N 133.3E STRONG LITTLE CHANGE
00UTC 04.08.2017 28.1N 132.0E STRONG LITTLE CHANGE
12UTC 04.08.2017 28.1N 131.0E STRONG INTENSIFYING SLIGHTLY
00UTC 05.08.2017 28.6N 130.3E INTENSE INTENSIFYING SLIGHTLY
12UTC 05.08.2017 29.2N 130.0E INTENSE INTENSIFYING SLIGHTLY
00UTC 06.08.2017 30.2N 129.9E INTENSE INTENSIFYING SLIGHTLY
12UTC 06.08.2017 31.5N 130.6E INTENSE LITTLE CHANGE
00UTC 07.08.2017 33.9N 132.0E INTENSE WEAKENING RAPIDLY
12UTC 07.08.2017 35.9N 133.5E STRONG WEAKENING RAPIDLY
00UTC 08.08.2017 36.7N 135.7E STRONG WEAKENING SLIGHTLY
12UTC 08.08.2017 38.5N 137.9E MODERATE WEAKENING SLIGHTLY
00UTC 09.08.2017 40.0N 139.4E MODERATE LITTLE CHANGE

[Alyono]

looks like it weakened some

A major fail by the models

[CrazyC83]

looks like it weakened some

A major fail by the models

Not surprising, since how often does a storm with an RMW of 70 nautical miles (or more?) deepen greatly? I don't know what they were smoking...

[euro6208]

WDPN31 PGTW 031500
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 07W (NORU) WARNING NR 56//
RMKS//
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
TYPHOON (TY) 07W (NORU), LOCATED APPROXIMATELY 307 NM EAST-
NORTHEAST OF KADENA AB, HAS TRACKED WEST-NORTHWESTWARD AT 08 KNOTS
OVER THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED SATELLITE
IMAGERY INDICATES A GRADUAL WEAKENING TREND WITH DEEP CONVECTIVE
BANDING WRAPPING INTO A BROAD, DEFINED CENTER. A 031224Z METOP-A
89GHZ IMAGE SHOWS THE BULK OF THE DEEP CONVECTIVE BANDING OVER THE
EASTERN SEMI-CIRCLE OF THE LOW-LEVEL CIRCULATION CENTER WITH SHALLOW
BANDING ELSEWHERE. THE INITIAL INTENSITY IS ASSESSED AT 75 KNOTS
BASED ON DVORAK CURRENT INTENSITY ESTIMATES OF 4.5 (77 KNOTS) FROM
PGTW AND KNES, AND A 030914Z SATCON ESTIMATE OF 76 KNOTS. UPPER-
LEVEL ANALYSIS REVEALS A FAVORABLE ENVIRONMENT WITH LOW VERTICAL
WIND SHEAR AND GOOD POLEWARD OUTFLOW. TY 07W IS TRACKING ALONG THE
SOUTHERN PERIPHERY OF A DEEP-LAYERED SUBTROPICAL RIDGE (STR)
POSITIONED OVER THE KOREAN PENINSULA AND WESTERN JAPAN.
3. FORECAST REASONING.
A. NO CHANGE TO THE FORECAST TRACK PHILOSOPHY SINCE THE PREVIOUS
PROGNOSTIC REASONING MESSAGE. THIS FORECAST REMAINS HIGHLY
CONSISTENT WITH THE PREVIOUS FORECAST. THE 34-KNOT WIND RADII OVER
THE EASTERN SEMI-CIRCLE WERE ADJUSTED / VERIFIED BASED ON A DETAILED
ANALYSIS OF A RECENT PARTIAL ASCAT IMAGE.
B. TY 07W IS FORECAST TO TURN SHARPLY NORTHWARD AFTER TAU 36 AS A
DEEP SUBTROPICAL SHORTWAVE TROUGH DIGS ACROSS THE EAST CHINA SEA AND
ERODES THE WESTERN PERIPHERY OF THE STR. THE SYSTEM IS EXPECTED TO
MAKE LANDFALL ALONG THE WESTERN CENTRAL COAST OF KYUSHU JUST PRIOR
TO TAU 72. AVAILABLE DYNAMIC GUIDANCE IS IN GOOD (MUCH IMPROVED)
AGREEMENT WITH A 90-NM SPREAD IN SOLUTIONS AT TAU 72 (WITH THE
EXCEPTION OF NAVGEM, WHICH IS TRACKING THE SYSTEM OVER SHIKOKU). TY
07W HAS WEAKENED DIURNALLY, HOWEVER, LOW-LEVEL STRUCTURE REMAINS
WELL ORGANIZED SO TY 07W IS EXPECTED TO RE-INTENSIFY AS IT TRACKS
SOUTH OF KYUSHU AND POLEWARD OUTFLOW IMPROVES AHEAD OF THE
AFOREMENTIONED SHORTWAVE TROUGH. NEAR TAU 48, SOME WEAKENING IS
EXPECTED AS THE SYSTEM APPROACHES KYUSHU DUE TO INCREASING
INTERACTION WITH LAND. OVERALL, THERE IS MODERATE CONFIDENCE IN THIS
PORTION OF THE FORECAST TRACK DUE TO THE TIMING OF THE SHARP
POLEWARD TRACK CHANGE AND TIMING / ORIENTATION OF THE APPROACHING
SHORTWAVE TROUGH.
C. AFTER TAU 72, TY 07W IS FORECAST TO TRACK NORTH-NORTHEASTWARD
ALONG THE WESTERN PERIPHERY OF THE POLEWARD-AMPLIFIED STR. THE
SYSTEM IS NOT EXPECTED TO UNDERGO SIGNIFICANT EXTRA-TROPICAL
TRANSITION (ETT) UNTIL IT TRACKS INTO THE SEA OF JAPAN DUE TO THE
LACK OF A DEEP MIDLATITUDE, BAROCLINIC TROUGH. INSTEAD THE STR IS
FORECAST TO RE-ORIENT IN A POLEWARD CONFIGURATION, WHICH WILL
PRODUCE A SLOWER, MORE ATYPICAL POLEWARD TRACK. TY 07W SHOULD WEAKEN
RAPIDLY AS IT TRACKS OVER COOLER SST IN THE SEA OF JAPAN AND IS
FORECAST TO COMPLETE ETT BY TAU 120. OVERALL, THERE IS MODERATE
CONFIDENCE IN THE JTWC FORECAST TRACK.//
NNNN

[euro6208]

UW - CIMSS
ADVANCED DVORAK TECHNIQUE
ADT-Version 8.2.1
Tropical Cyclone Intensity Algorithm

----- Current Analysis -----
Date : 03 AUG 2017 Time : 171000 UTC
Lat : 28:19:21 N Lon : 132:29:46 E


CI# /Pressure/ Vmax
4.5 / 970.2mb/ 77.0kt


Final T# Adj T# Raw T#
4.5 4.4 4.4

Center Temp : +15.4C Cloud Region Temp : -49.3C

Scene Type : IRREGULAR CDO*

Positioning Method : SPIRAL ANALYSIS

Ocean Basin : WEST PACIFIC
Dvorak CI > MSLP Conversion Used : CKZ Method

Tno/CI Rules : Constraint Limits : NO LIMIT
Weakening Flag : OFF
Rapid Dissipation Flag : OFF

C/K/Z MSLP Estimate Inputs :
- Average 34 knot radii : N/A
- Environmental MSLP : 1008mb

Satellite Name : HIM-8
Satellite Viewing Angle : 34.3 degrees

****************************************************

[euro6208]

EURO and GFS now agrees on track and still stubbornly strengthens Noru quite rapidly.

[euro6208]

861 mb right before landfall...

[euro6208]

HWRF seems to be on track...

[euro6208]

Very large eye appearing on radar.

[euro6208]

WDPN31 PGTW 032100
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 07W (NORU) WARNING NR 57//
RMKS//
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
TYPHOON (TY) 07W (NORU), LOCATED APPROXIMATELY 314 NM
SOUTH-SOUTHEAST OF SASEBO, JAPAN, HAS TRACKED WESTWARD AT 07 KNOTS
OVER THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED SATELLITE IMAGERY
INDICATES A GRADUAL WEAKENING TREND WITH DEEP CONVECTIVE BANDING
WRAPPING INTO A BROAD AND RAGGED 50-NM EYE. THE INITIAL POSITION IS
BASED ON THE EYE FEATURE WITH HIGH CONFIDENCE. THE INITIAL INTENSITY
OF 75 KNOTS IS BASED ON OBJECTIVE AND AGENCY DVORAK CURRENT INTENSITY
ESTIMATES OF T3.9 TO T4.5. UPPER-LEVEL ANALYSIS INDICATES A
MARGINALLY FAVORABLE ENVIRONMENT WITH LOW TO MODERATE (10-15 KNOT)
VERTICAL WIND SHEAR (VWS) AND GOOD POLEWARD OUTFLOW. TY 07W IS
TRACKING ALONG THE SOUTHERN PERIPHERY OF A DEEP-LAYERED SUBTROPICAL
RIDGE (STR) OVER THE KOREAN PENINSULA AND WESTERN JAPAN.
3. FORECAST REASONING.
A. NO CHANGE TO THE FORECAST TRACK PHILOSOPHY SINCE THE PREVIOUS
PROGNOSTIC REASONING MESSAGE.
B. TY 07W IS FORECAST TO TURN SHARPLY NORTHWARD AFTER TAU 36 AS A
DEEP SUBTROPICAL SHORTWAVE TROUGH DIGS ACROSS THE EAST CHINA SEA AND
ERODES THE WESTERN PERIPHERY OF THE STR. THE SYSTEM IS EXPECTED TO
MAKE LANDFALL ALONG THE WESTERN CENTRAL COAST OF KYUSHU JUST PRIOR
TO TAU 72. THE SYSTEM IS EXPECTED TO GRADUALLY RE-INTENSIFY OVER THE
NEXT 36 HOURS AS POLEWARD OUTFLOW INCREASES WITH THE APPROACH OF THE
SUBTROPICAL WAVE TROUGH AND THE PREVAILING WESTERLIES ASSOCIATED WITH
IT. AFTERWARDS, LAND INTERACTION AND INCREASING VWS WILL RAPIDLY
ERODE THE SYSTEM. AVAILABLE DYNAMIC GUIDANCE REMAINS IN GOOD
AGREEMENT. OVERALL, THERE IS LOW TO MODERATE CONFIDENCE IN THIS
PORTION OF THE FORECAST TRACK DUE TO THE TIMING OF THE SHARP
POLEWARD TRACK CHANGE AND TIMING/ORIENTATION OF THE APPROACHING
SHORTWAVE TROUGH.
C. AFTER TAU 72, TY 07W IS FORECAST TO TRACK NORTH-NORTHEASTWARD
ALONG THE WESTERN PERIPHERY OF THE STR. THE SYSTEM IS NOT EXPECTED TO
UNDERGO SIGNIFICANT EXTRA-TROPICAL TRANSITION (ETT) UNTIL IT TRACKS
INTO THE SEA OF JAPAN BY TAU 96 DUE TO THE LACK OF A DEEP
MIDLATITUDE, BAROCLINIC TROUGH. INSTEAD THE STR IS FORECAST TO
RE-ORIENT IN A POLEWARD CONFIGURATION, WHICH WILL PRODUCE A SLOWER,
MORE ATYPICAL POLEWARD TRACK. TY 07W SHOULD CONTINUE TO WEAKEN
RAPIDLY WITH STRONG VWS AND COOLER SST IN THE SEA OF JAPAN AND IS
FORECAST TO COMPLETE ETT BY TAU 120. OVERALL, THERE IS MODERATE
CONFIDENCE IN THE JTWC FORECAST TRACK.//
NNNN

[euro6208]

Closing in...

[euro6208]

Josh Morgerman aka iCyclone will be chasing this.

https://www.facebook.com/iCyclone

[Alyono]

if we don't see structural improvements, this may weaken to a TS before reaching Kyushu

[Digital-TC-Chaser]

Land fall wind data will be interesting, tbh with the size (friction) and current sat-present
and radar not thinking Noru will be much.


rain rates is not high either on this radar with what i can see.Can't see the back end tho.

[euro6208]

Hmm. Look at this. A much larger eye likely to appear? The inner eyewall looks to have collapsed. EWC?

[Digital-TC-Chaser]

YR is EC data made easy for the public to use into a general forecast.
Naze looks to be maybe the closest point to the system until it landfall on the mainland.
ssw of the cyclone.

https://www.yr.no/place/Japan/Kagoshima/Naze/
forecast.

[dexterlabio]

Josh Morgerman aka iCyclone will be chasing this.

https://www.facebook.com/iCyclone

I saw his tweets about Nesat not worthy to chase because of it being just a Cat1. The way things are going Noru may just be a low-end Cat1 (or perhaps a TS) upon landfall, just like Lionrock which had also been wildly overblown by the models last year. This one keeps on growing a larger (but more unstable) eye. I'm interested to know how strong the winds around that humongous eye could be. I always wonder if a distinct eye is a sureball indication of wind speed of at least 64 knots, or if there are cases where the winds around a visible eye are short of typhoon/hurricane strength.

[1900hurricane]

Clearly a dry air curl.

[mrbagyo]

Has there been any tropical cyclone before that went from being a Big eyed annular into a pinhole compact?

Probably not. Pinhole storms form in relatively high-SST, high-instability environments. Big eyed annular storms form in relatively low-SST, low-instability environments. It's easy to go from the former to the latter, but unusual to go in the opposite direction.

not pinhole compact, but it looks like Noru's eye is actually contracting atm