WPAC: NORU - Low

[Sciencerocks]

The JMA made the right choice upgrading this to a depression.

This has Nice convection and the LLC is obvious.

This is better looking then
Bret
Cindy
or Don

[euro6208]

Certainly a TS now...

[euro6208]

[Grifforzer]

50 knots - 998 hPa on the surface map outlook for "95W" in 48 hours.

[1900hurricane]

I'd probably wait for ASCAT before calling for an upgrade. I'm not confident enough in pulling the trigger based on the latest microwave imagery.

[euro6208]

WTPN21 PGTW 200530
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE FORMATION ALERT//
RMKS/
1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN
180 NM EITHER SIDE OF A LINE FROM 26.7N 160.0E TO 29.8N 154.3E
WITHIN THE NEXT 12 TO 24 HOURS. AVAILABLE DATA DOES NOT JUSTIFY
ISSUANCE OF NUMBERED TROPICAL CYCLONE WARNINGS AT THIS TIME. WINDS
IN THE AREA ARE ESTIMATED TO BE 20 TO 25 KNOTS. METSAT IMAGERY AT
200500Z INDICATES THAT A CIRCULATION CENTER IS LOCATED NEAR 27.0N
159.6E. THE SYSTEM IS MOVING NORTHWESTWARD AT 05 KNOTS.
2. REMARKS: THE AREA OF CONVECTION (INVEST 95W) PREVIOUSLY LOCATED
NEAR 26.3N 159.8E IS NOW LOCATED NEAR 27.0N 159.6E, APPROXIMATELY
1140 NM EAST-SOUTHEAST OF TOKYO, JAPAN. ANIMATED MULTISPECTRAL
SATELLITE IMAGERY DEPICTS A BROAD LOW-LEVEL CIRCULATION CENTER
(LLCC) WITH PERSISTENT CENTRAL CONVECTION AND DEFINED LOW-LEVEL
CLOUD LINES WRAPPING INO THE CENTER. A 192318Z METOP-A 89GHZ IMAGE
DEPICTS FRAGMENTED DEEP CONVECTIVE BANDS WITH SHALLOW BANDING
WRAPPING AROUND A DEFINED LLCC. A 192232Z PARTIAL ASCAT IMAGE SHOWS
20-25 KNOT WINDS OVER THE EASTERN SEMI-CIRCLE WITH ISOLATED 30-KNOT
WINDS TO THE SOUTHEAST. UPPER-LEVEL ANALYSIS INDICATES A POINT
SOURCE POSITIONED OVER THE CENTER PROVIDING GOOD OUTFLOW ALOFT AND
LOW VERTICAL WIND SHEAR. ADDITIONALLY, SST VALUES 29 TO 30C ARE
CONDUCIVE FOR FURTHER DEVELOPMENT. ALTHOUGH THE SYSTEM RETAINS SOME
SUBTROPICAL CHARACTERISTICS, IT APPEARS TO BE QUICKLY TRANSITIONING
TO A TROPICAL, WARM-CORE SYSTEM. GLOBAL MODELS INDICATE A
NORTHWESTWARD TRACK WITH WEAK DEVELOPMENT OVER THE NEXT TWO DAYS,
HOWEVER, SOME CONSOLIDATION APPEARS LIKELY DUE TO THE FAVORABLE
ENVIRONMENTAL CONDITIONS. MAXIMUM SUSTAINED SURFACE WINDS ARE
ESTIMATED AT 20 TO 25 KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED
TO BE NEAR 1004 MB. THE POTENTIAL FOR THE DEVELOPMENT OF A
SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24 HOURS IS HIGH.
3. THIS ALERT WILL BE REISSUED, UPGRADED TO WARNING OR CANCELLED BY
210530Z.//
NNNN

[euro6208]

TPPN10 PGTW 200642

A. TROPICAL DISTURBANCE 95W (E OF IWO TO)

B. 20/0600Z

C. 27.18N

D. 159.72E

E. FIVE/HMWRI8

F. T1.5/1.5 STT: D0.5/03HRS

G. IR/EIR/VIS/MSI

H. REMARKS: 40A/PBO SBC/ANMTN. .30 WRAP YIELDS A DT OF 1.5. PT
AND MET ARE CURRENTLY UNAVAILABLE. DBO DT.

I. ADDITIONAL POSITIONS: NONE


MARTINEZ

[euro6208]

TPPN10 PGTW 200901

A. TROPICAL DISTURBANCE 95W (NW OF WAKE ISLAND)

B. 20/0830Z

C. 27.42N

D. 159.45E

E. FIVE/HMWRI8

F. T1.5/1.5/D0.5/24HRS STT: S0.0/03HRS

G. IR/EIR

H. REMARKS: 38A/PBO SBC/ANMTN. .30 WRAP YIELDS A DT OF 1.5. PT
AND MET AGREE. DBO DT.

I. ADDITIONAL POSITIONS: NONE


MARTINEZ

[euro6208]

TXPQ23 KNES 200917
TCSWNP

A. TROPICAL DISTURBANCE (95W)

B. 20/0830Z

C. 27.6N

D. 159.8E

E. FIVE/HIMAWARI-8

F. T1.5/1.5/S0.0/24HRS

G. IR/EIR/SWIR

H. REMARKS...SYSTEM LLC IS DIFFICULT TO FIND IN BOTH MICROWAVE AND
IR IMAGERY. CONVECTION WRAPS ALMOST .3 ON LOG10 SPIRAL YIELDING A DT
OF 1.5. MET AND PT AGREE. FT IS BASED ON MET DUE TO DIFFICULTY FIND LLC.

I. ADDL POSITIONS

NIL


...KIBLER

[euro6208]

Another big burst of convection.

[euro6208]

Been Noru for a few days now...

[NotoSans]

Up to CI 2.0 at 18Z from JMA meaning that they would probably pull the trigger. I personally think that it's an appropriate time to name the system.

Edit: JMA kept it as a TD at their latest advisory.

[Sciencerocks]

http://www.ssd.noaa.gov/PS/TROP/floater ... imated.gif

I agree 100% with euro that this is a tropical storm. It is being impacted by some northerly shear but it is what it is.

[euro6208]

WDPN31 PGTW 202100
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL DEPRESSION 07W (SEVEN)
WARNING NR 001//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
TROPICAL DEPRESSION 07W (SEVEN), LOCATED APPROXIMATELY 1044 NM
EAST-SOUTHEAST OF YOKOSUKA, JAPAN, HAS TRACKED WESTWARD AT 07 KNOTS
OVER THE PAST SIX HOURS. ANIMATED INFRARED SATELLITE IMAGERY DEPICTS
FLARING DEEP CONVECTION PRIMARILY FOCUSED TO THE SOUTH OF THE LOW
LEVEL CIRCULATION CENTER (LLCC), WHICH IS CURRENTLY OBSCURED BY THE
UPPER LEVEL CIRRUS SHIELD. THE INITIAL POSITION IS PLACED WITH FAIR
CONFIDENCE AND IS BASED ON BOTH SATELLITE FIXES AND A 201745Z 89 GHZ
AMSU-B IMAGE CONFIRMING SOME WEAK CONVECTIVE BANDING INTO THE LLCC
WITH THE MAJORITY OF THE MOST INTENSE CONVECTION LIMITED TO THE
SOUTHEAST QUADRANT. THE INITIAL INTENSITY ASSESSMENT OF 25 KNOTS IS
BASED ON BOTH SUBJECTIVE CURRENT INTENSITY DVORAK ESTIMATES T2.0 (30
KNOTS) FROM PGTW, LOWERED BY FIVE KNOTS DUE TO THE DISPLACEMENT OF
THE DEEPEST CONVECTION FROM THE LLCC. ENVIRONMENTAL ANALYSIS SHOWS
FAVORABLE CONDITIONS WITH LOW VERTICAL WIND SHEAR (VWS), WARM SSTS
NEAR 30 CELSIUS, AND GOOD OUTFLOW DUE TO AN UPPER-LEVEL ANTICYCLONE
JUST NORTH OF THE SYSTEM. TD 07W IS TRACKING WEST-NORTHWESTWARD
ALONG THE SOUTHWESTERN PERIPHERY OF A DEEP-LAYER SUBTROPICAL RIDGE
(STR) CENTERED SOUTH OF THE ALEUTIAN ISLANDS.
3. FORECAST REASONING.
A. THIS IS THE FIRST WARNING ON THIS SYSTEM AND ESTABLISHES THE
FORECAST REASONING.
B. TD 07W WILL CONTINUE TRACKING TOWARDS THE WEST-NORTHWEST FOR
THE NEXT 72 HOURS UNDER THE INFLUENCE OF THE DEEP-LATER STR. TD 07W
IS FORECAST TO SLOWLY INTENSIFY THROUGH THE FIRST 72 HOURS OF THE
FORECAST AS ENVIRONMENTAL CONDITIONS WILL REMAIN MODERATELY
FAVORABLE. THE UPPER LEVEL ANTICYCLONE MENTIONED IN PARAGRAPH 2A
WILL REMAIN IN CLOSE PROXIMITY TO THE LLCC, PROVIDING MODERATE
EXHAUST AND LOW TO MODERATE VWS. SSTS CONTINUE TO BE SUPPORTIVE,
REMAINING IN 29-30 DEG CELSIUS RANGE. AFTER TAU 48, TD 07W SLOWS
SIGNIFICANTLY AS THE STEERING STR WEAKENS DUE TO THE APPROACH OF A
SUBTROPICAL SYSTEM (INVEST 97W) CURRENTLY LOCATED SOUTHWEST OF
MIDWAY ISLAND. BY TAU 72, TD 07W WILL COME WITHIN 600 NM OF THIS
SUBTROPICAL LOW WITH THE POTENTIAL FOR BINARY INTERACTION BEGINNING
AROUND TAU 72. AVAILABLE NUMERICAL GUIDANCE IS IN TIGHT AGREEMENT
THROUGH TAU 48, BUT BEGIN TO SHOW INCREASING DIVERGENCE BY TAU 72,
ATTRIBUTED TO THE POTENTIAL BINARY INTERACTION SCENARIO.
C. AFTER TAU 72, TD 07W IS FORECAST TO BECOME QUASI-STATIONARY AS
THE STEERING ENVIRONMENT WEAKENS AND THE SYSTEM BECOMES CAPTURED BY
THE SUBTROPICAL LOW. THE TRACK AFTER TAU 72 SHIFTS RAPIDLY TOWARDS
THE SOUTHEAST UNDER THE INFLUENCE OF THE BINARY INTERACTION WITH THE
SUBTROPICAL LOW AND ACCELERATES. TD 07W WILL CONTINUE TO INTENSIFY
THROUGH TAU 96, AS A UPPER-LEVEL POINT SOURCE DEVELOPS OVER TOP OF
THE SYSTEM BY THIS TIME, BEFORE BEGINNING TO SLOWLY WEAKEN THROUGH
THE REMAINDER OF THE FORECAST DUE TO INCREASING NORTHERLY VWS.
NUMERICAL MODEL GUIDANCE IS TRIFURCATED AFTER TAU 72, WITH COAMPS-TC
SHOWING THE SYSTEM CONTINUING STRAIGHT NORTHWEST AND NOT UNDERGOING
BINARY INTERACTION, AND ECMWF, GFS AND HWRF ALL SHOWING A SOUTHWARD
TURN TOWARDS THE SOUTHEAST AND THE REMAINDER OF THE MODELS SHOWING A
NORTHWARD TURN. THE JTWC TRACK LIES NEAR THE MULTI-MODEL CONSENSUS,
BUT SLIGHTLY CLOSER TOWARDS THE SOUTHERN GROUP OF MODEL TRACKERS. A
POTENTIAL ALTERNATE SCENARIO IS THAT THE SUBTROPICAL LOW TRACKS
FURTHER TO THE NORTH AT A SLOWER SPEED OF ADVANCE AND DOES NOT
CAPTURE TD 07W IN A BINARY INTERACTION SCENARIO. IN THE EVENT THIS
SCENARIO COMES ABOUT, TD 07W WILL TRACK NORTHWESTWARD AND EVENTUALLY
RECURVE TOWARDS THE NORTHEAST AS IT INTERACTS WITH THE MID-LATITUDE
WESTERLIES EAST OF JAPAN. DUE TO THE HIGH UNCERTAINTY RELATED TO THE
BINARY INTERACTION WITH THE SUBTROPICAL LOW AND THE DISTINCT MODEL
DIVERGENCE PAST TAU 72, THERE IS LOW CONFIDENCE IN THE OVERALL
FORECAST TRACK.//
NNNN

[euro6208]

This one is in no rush to leave. GFS keeps it around for 9 days or so and like EURO has a Fujiwhara effect with 97W.

[euro6208]

[euro6208]

GFS explodes this big time. Bottoms at 884 mb

[euro6208]

I wonder how much ACE is getting lost.

[1900hurricane]

Now named Tropical Storm Noru.

TS 1705 (Noru)
Issued at 01:00 UTC, 21 July 2017

<Analysis at 00 UTC, 21 July>
Scale -
Intensity -
Center position N27°20' (27.3°)
E158°30' (158.5°)
Direction and speed of movement W 10 km/h (6 kt)
Central pressure 1008 hPa
Maximum wind speed near center 18 m/s (35 kt)
Maximum wind gust speed 25 m/s (50 kt)
≥ 30 kt wind area ALL 220 km (120 NM)

<Forecast for 00 UTC, 22 July>
Intensity -
Center position of probability circle N28°05' (28.1°)
E155°10' (155.2°)
Direction and speed of movement WNW 15 km/h (8 kt)
Central pressure 1004 hPa
Maximum wind speed near center 20 m/s (40 kt)
Maximum wind gust speed 30 m/s (60 kt)
Radius of probability circle 90 km (50 NM)

<Forecast for 00 UTC, 23 July>
Intensity -
Center position of probability circle N28°30' (28.5°)
E153°50' (153.8°)
Direction and speed of movement WNW Slow
Central pressure 992 hPa
Maximum wind speed near center 23 m/s (45 kt)
Maximum wind gust speed 35 m/s (65 kt)
Radius of probability circle 180 km (95 NM)

<Forecast for 00 UTC, 24 July>
Intensity -
Center position of probability circle N28°40' (28.7°)
E153°10' (153.2°)
Direction and speed of movement Almost stationary
Central pressure 990 hPa
Maximum wind speed near center 25 m/s (50 kt)
Maximum wind gust speed 35 m/s (70 kt)
Radius of probability circle 240 km (130 NM)

[NotoSans]

Upgraded to TS Noru by the JMA.