WPAC: HALONG - Post-Tropical

[aspen]

I wouldn’t be surprised if 99W is already a tropical storm. It’s producing some massive bursts of convection and has excellent outflow in the northern quadrants. It could be possible that 99W will exceed model expectations and intensify faster and greater than anticipated, based on how well it appears to be developing within a favorable environment.

[wxman57]

Plenty of 35kt winds on the recent ASCAT-C pass. This is a TS. JMA uses 10-min winds, so they won't upgrade it until winds are stronger.

[mrbagyo]

Bullseye 1112z ASCAT MetOp C pass caught some 40 knots - definitely a TS now - circulation looks quite open to the west though - might be closed by now given the current rate of organization .

[mrbagyo]

Amazing convective explosion

[Highteeld]

https://s4.gifyu.com/images/rbtop_lalo-animated2.gif


https://s4.gifyu.com/images/rb_lalo-animated.gif
Amazing convective explosion

Some of those overshooting tops look ~ -100*C

[aspen]

https://s4.gifyu.com/images/rbtop_lalo-animated2.gif


https://s4.gifyu.com/images/rb_lalo-animated.gif
Amazing convective explosion

Some of those overshooting tops look ~ -100*C

Agreed, it’s maxed out the color scale on WeatherNerds’ infrared floater and just about every other filter. I haven’t seen a depression this vigorous before, and based on its satellite appearance, this is probably Tropical Storm Halong by now.

[Nancy Smar]

WTPQ20 RJTD 021500
RSMC TROPICAL CYCLONE ADVISORY
NAME TS 1923 HALONG (1923) UPGRADED FROM TD
ANALYSIS
PSTN 021500UTC 13.3N 156.9E POOR
MOVE NW 12KT
PRES 1000HPA
MXWD 035KT
GUST 050KT
30KT 180NM NORTHEAST 90NM SOUTHWEST
FORECAST
24HF 031500UTC 17.0N 153.9E 60NM 70%
MOVE NW 10KT
PRES 990HPA
MXWD 055KT
GUST 080KT =

[aspen]

Given its rapid development and convective blossoming today, is it possible for Halong to explosively intensify over the next few days? The current JTWC track does show significant intensification (65 to 105 kt in just 24 hours between 11/4 and 11/5), but I don’t know if the environment is that conductive for Halong to reach Category 4 or 5 intensity before it starts becoming post-tropical in 4-5 days.

[Hayabusa]

The JMA forecast track for Halong only goes up to 1 day instead of 5 days despite being named, they don't expect much from it?

[Hayabusa]

WDPN31 PGTW 021500
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL DEPRESSION 24W (TWENTYFOUR)
WARNING NR 01//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
TROPICAL DEPRESSION (TD) 24W (TWENTYFOUR), LOCATED APPROXIMATELY
713 NM EAST OF ANDERSEN AFB, GUAM, HAS TRACKED NORTHWESTWARD AT 08 KNOTS
OVER THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED SATELLITE IMAGERY
DEPICTS A LARGE AREA OF ASYMMETRIC DEEP CONVECTION LOCATED OVER AN
OBSCURED, ELONGATED LOW-LEVEL CIRCULATION CENTER (LLCC). A 021031Z MHS
89GHZ MICROWAVE IMAGE DEPICTS A PARTIALLY-EXPOSED, BROAD LLCC WITH THE
BULK OF THE DEEP CONVECTION DISPLACED OVER THE EASTERN SEMICIRCLE. A
021112Z ASCAT-C IMAGE INDICATES THAT THE WINDFIELD HAS STRENGTHENED
QUICKLY AND FORMED INTO A CLOSED CIRCULATION WITH A LARGE SWATH OF
30 KNOT WINDS OVER THE EASTERN SEMICIRCLE AND AN ISOLATED POCKET OF
35-40 KNOT WINDS OVER THE SOUTHEAST QUADRANT. DUE TO THE BROAD LLCC,
THERE IS FAIR CONFIDENCE IN THE CURRENT POSITION AND TRACK MOTION. THE
CURRENT INTENSITY IS ASSESSED AT 30 KNOTS BASED ON AN OVERALL EVALUATION
OF THE WINDFIELD. UPPER-LEVEL ANALYSIS REVEALS A FAVORABLE ENVIRONMENT
WITH NEAR-RADIAL OUTFLOW AND LOW VERTICAL WIND SHEAR. ADDITIONALLY, SST
VALUES OF 29-30C ARE CONDUCIVE FOR DEVELOPMENT. TD 24W IS TRACKING ALONG
THE SOUTHWESTERN PERIPHERY OF A DEEP-LAYERED SUBTROPICAL RIDGE (STR).
3. FORECAST REASONING.
A. THIS IS THE FIRST PROGNOSTIC REASONING MESSAGE AND SETS THE
FORECAST PHILOSOPHY.
B. TD 24W IS FORECAST TO TRACK NORTHWESTWARD TO NORTH-NORTHWESTWARD
THROUGH TAU 72 AS IT TRACKS ALONG THE WESTERN PERIPHERY OF THE STR AND
APPROACHES THE STR AXIS. THE SYSTEM WILL INTENSIFY UNDER FAVORABLE
CONDITIONS TO A PEAK OF 105 KNOTS WITH INCREASING POTENTIAL FOR RAPID
INTENSIFICATION AFTER TAU 48 DUE TO ENHANCED POLEWARD OUTFLOW INTO THE
MIDLATITUDE WESTERLIES.
C. IN THE EXTENDED PERIOD, TD 24W WILL RECURVE NORTHEASTWARD AND IS
FORECAST TO BEGIN EXTRA-TROPICAL TRANSITION (ETT) AS IT INTERACTS WITH
THE MIDLATITUDE WESTERLIES. THE SYSTEM SHOULD COMPLETE ETT BY TAU 120
AS IT GAINS FRONTAL CHARACTERISTICS AND BECOMES EMBEDDED WITHIN THE
MIDLATITUDE WESTERLIES. TD 24W WILL WEAKEN RAPIDLY DUE TO INCREASING
VERTICAL WIND SHEAR AND COOLER SST BY TAU 120. DUE TO THE BROAD NATURE
OF THE LLCC AND LARGE SPREAD IN SOLUTIONS IN THE EXTENDED PERIOD, THERE
IS OVERALL LOW CONFIDENCE IN THE JTWC FORECAST TRACK.//
NNNN

[mrbagyo]

Given its rapid development and convective blossoming today, is it possible for Halong to explosively intensify over the next few days? The current JTWC track does show significant intensification (65 to 105 kt in just 24 hours between 11/4 and 11/5), but I don’t know if the environment is that conductive for Halong to reach Category 4 or 5 intensity before it starts becoming post-tropical in 4-5 days.

[Highteeld]

Given its rapid development and convective blossoming today, is it possible for Halong to explosively intensify over the next few days? The current JTWC track does show significant intensification (65 to 105 kt in just 24 hours between 11/4 and 11/5), but I don’t know if the environment is that conductive for Halong to reach Category 4 or 5 intensity before it starts becoming post-tropical in 4-5 days.

If it forms a pinhole eye, anything is possible really. If, being the operative word, of course.

[Hayabusa]

Ok new updated forecast now includes 5 days

TS 1923 (Halong)
Issued at 18:50 UTC, 2 November 2019

<Analysis at 18 UTC, 2 November>
Scale -
Intensity -
Center position N13°35' (13.6°)
E156°50' (156.8°)
Direction and speed of movement WNW 20 km/h (11 kt)
Central pressure 1000 hPa
Maximum wind speed near center 18 m/s (35 kt)
Maximum wind gust speed 25 m/s (50 kt)
≥ 30 kt wind area NE 330 km (180 NM)
SW 170 km (90 NM)

<Forecast for 06 UTC, 3 November>
Intensity -
Center position of probability circle N15°30' (15.5°)
E155°20' (155.3°)
Direction and speed of movement NW 20 km/h (12 kt)
Central pressure 992 hPa
Maximum wind speed near center 25 m/s (50 kt)
Maximum wind gust speed 35 m/s (70 kt)
Radius of probability circle 60 km (30 NM)

<Forecast for 18 UTC, 3 November>
Intensity -
Center position of probability circle N17°00' (17.0°)
E153°50' (153.8°)
Direction and speed of movement NW 20 km/h (10 kt)
Central pressure 985 hPa
Maximum wind speed near center 30 m/s (60 kt)
Maximum wind gust speed 45 m/s (85 kt)
Radius of probability circle 110 km (60 NM)
Storm warning area ALL 160 km (85 NM)

<Forecast for 18 UTC, 4 November>
Intensity -
Center position of probability circle N19°10' (19.2°)
E152°30' (152.5°)
Direction and speed of movement NNW 10 km/h (6 kt)
Central pressure 960 hPa
Maximum wind speed near center 40 m/s (80 kt)
Maximum wind gust speed 60 m/s (115 kt)
Radius of probability circle 190 km (100 NM)
Storm warning area ALL 260 km (140 NM)

<Forecast for 18 UTC, 5 November>
Intensity Very strong
Center position of probability circle N22°05' (22.1°)
E152°25' (152.4°)
Direction and speed of movement N 15 km/h (7 kt)
Central pressure 955 hPa
Maximum wind speed near center 45 m/s (85 kt)
Maximum wind gust speed 60 m/s (120 kt)
Radius of probability circle 300 km (160 NM)
Storm warning area ALL 390 km (210 NM)

<Forecast for 18 UTC, 6 November>
Intensity -
Center position of probability circle N25°10' (25.2°)
E157°30' (157.5°)
Direction and speed of movement ENE 25 km/h (14 kt)
Central pressure 975 hPa
Maximum wind speed near center 35 m/s (70 kt)
Maximum wind gust speed 50 m/s (100 kt)
Radius of probability circle 430 km (230 NM)
Storm warning area ALL 480 km (260 NM)

<Forecast for 18 UTC, 7 November>
Intensity -
Center position of probability circle N25°30' (25.5°)
E164°30' (164.5°)
Direction and speed of movement E 30 km/h (16 kt)
Central pressure 992 hPa
Maximum wind speed near center 25 m/s (50 kt)
Maximum wind gust speed 35 m/s (70 kt)
Radius of probability circle 600 km (325 NM)

[Hayabusa]

24W TWENTYFOUR 191102 1800 13.7N 156.5E WPAC 35 998

[Tailspin]

https://imgur.com/xnEY2ru

8hr loop https://imgur.com/uvXejYH

EC
http://www.atmos.albany.edu/student/tbu ... 2019110212

[1900hurricane]

The JMA forecast track for Halong only goes up to 1 day instead of 5 days despite being named, they don't expect much from it?

I'm not entirely sure, but the initial forecast might have been only one day because the upgrade came at an off-hour fix (15Z). Depending on their protocol, JMA might only do full forecast packages/updates at the main fix times.

[Tailspin]

https://imgur.com/eDy5UlF

[mrbagyo]

Half naked

[mrbagyo]

There's a chance this could explode tonight.

[1900hurricane]

 https://twitter.com/1900hurricane/status/1190996586630914049