WPAC: SINLAKU - Typhoon

[MarioProtVI]

If this becomes a CAT5 before the 17th, would it be the earliest storm to do so? I think Surigae was on April 17th, but this has room to beat that. But were there any earlier CAT5s that I am missing?

Typhoon Ophelia of 1958

Beware of 50s and 60s intensities as it’s been confirmed estimates during that period were too high, so I wouldn’t bet on that as a record setter.

[sasha_B]

Sinlaku's eye has cleared to OW now - starting to drift above 0°C in some frames - and it's surrounded by W with a widening CMG ring around it. ADT remains below T6.0, but mostly because it only started using the eye pattern at 2130z, fixing the center well to the west of its actual position for almost 6 hours after the eye first appeared - and the last raw fix was T7.3. Even NOAA acknowledged the T6.5 presentation on their 2330z bulletin:

11/2330Z: DG EYE SURROUNDED BY W AND EMBEDDED IN W RESULTS IN E# OF 6.0 AND EADJ OF +0.5 FOR A DT OF 6.5. 6 HR AVG GIVES A DT=6.3 SO CONSTRAINTS BROKEN. UPR-LVL OUTFLOW VERY GOOD-EXCELLENT ALQDS. MET AND PT=6.0. FT BASED ON 6 HR AVG DT.

I'd place Sinlaku's current intensity at 115 kt, 938 hPa as a lower bound; possibly it is approaching 125 kt.

The posts in this forum are NOT official forecasts and should not be used as such. They are just the opinion of the poster and may or may not be backed by sound meteorological data. They are NOT endorsed by any professional institution or STORM2K. For official information, please refer to products from the NHC and NWS.

[Yellow Evan]

If this becomes a CAT5 before the 17th, would it be the earliest storm to do so? I think Surigae was on April 17th, but this has room to beat that. But were there any earlier CAT5s that I am missing?

Just off official (semi-reliable) records, Typhoon Mitag 2002 and Typhoon Maysak 2015 and Typhoon Wutip 2019 all reached Category 5 before April.

[cycloneye]

A. 04W (SINLAKU)

B. 11/2330Z

C. 9.8N

D. 151.2E

E. ONE/HIMAWARI-9

F. T6.5/6.5

G. IR/EIR/VIS/SSMIS/WSFM

H. REMARKS...DG EYE SURROUNDED BY W AND EMBEDDED IN W RESULTS IN E#
OF 6.0 AND EADJ OF +0.5 FOR A DT OF 6.5. 6 HR AVG GIVES A DT=6.3 SO
CONSTRAINTS BROKEN. UPR-LVL OUTFLOW VERY GOOD-EXCELLENT ALQDS. MET AND
PT=6.0. FT BASED ON 6 HR AVG DT.

[mrbagyo]

[Yellow Evan]

CDO smoothing out but eye not fully cleared. Category 5 overnight barring an ERC.

[Hurricane2000]

The structure is quite amazing.

[cycloneye]

Track now is between Rota and Saipan.

[sasha_B]

As of 0230z, an OW (>15°C) eye surrounded by CMG (with an almost intact CDG ring & cloud tops below －90°C in the eyewall) supports a DT of 7.5 (before applying constraints, which I believe would preclude such an intensity). FT 7.0 doesn't even require constraints to be broken, and even if you treat a few white pixels in the NW quadrant as sufficient to rule out an E# of 6.5, an OW eye surrounded by W still yields DT7.0. Raw ADT has also reached T7.5, though ADT CI is "only" 6.3 (122 kt).

This should be 130～140 kt by 06z. It looks better than any storm we've seen this year, and there are no in situ data or nearby surface observations to suggest its intensity is any lower.

[Hurricane2022]

[Hurricane2022]

[Subtrop]

NMC:65m/s

Typhoon Message
20260412 11:15
National Meteorological Center No.115
Analysis Time: Apr. 12th 03 UTC
Name of TC: SINLAKU
Num. of TC: 2604
Current Location: 10.1°N 151.0°E
2-min. Average Max. Wind Speed: 65m/s（234km/h）
Central Pressure: 910hPa
Radius of 34knots Winds: NE 400km SE 380km SW 380km NW 400km
Radius of 50knots Winds: NE 120km SE 120km SW 120km NW 120km
Radius of 64knots Winds: NE 80km SE 80km SW 80km NW 80km
Forecast movement:next 24hrs SINLAKU will moving NW at speed of 17km/h

[Hurricane2022]

That's my good old jtwc academy

TPPN10 PGTW 120309

A. TYPHOON 04W (SINLAKU)

B. 12/0230Z

C. 10.02N

D. 150.89E

E. ONE/GK2A

F. T6.5/6.5/D2.0/24HRS STT: D0.5/03HRS

G. IR/EIR/VIS/MSI

H. REMARKS: 03A/PBO EYE/ANMTN. EYE EMBEDDED 55NM IN CDO YIELDS AN
E# OF 5.5. ADDED 0.5 FOR A WELL-DEFINED EYE AND ADDED 0.5 FOR BF TO
YIELD A DT OF 6.5. MET YIELDS 5.5. PT YIELDS 6.0. DBO DT.

I. ADDITIONAL POSITIONS: NONE


LINDGREN

[sasha_B]

NMC:65m/s

Typhoon Message
20260412 11:15
National Meteorological Center No.115
Analysis Time: Apr. 12th 03 UTC
Name of TC: SINLAKU
Num. of TC: 2604
Current Location: 10.1°N 151.0°E
2-min. Average Max. Wind Speed: 65m/s（234km/h）
Central Pressure: 910hPa
Radius of 34knots Winds: NE 400km SE 380km SW 380km NW 400km
Radius of 50knots Winds: NE 120km SE 120km SW 120km NW 120km
Radius of 64knots Winds: NE 80km SE 80km SW 80km NW 80km
Forecast movement:next 24hrs SINLAKU will moving NW at speed of 17km/h

Much closer to the mark than 110 kt / 944 hPa, at least...

But in all seriousness - and regardless of quibbles about intensity - this must be a particularly concerning situation for Rota & the Northern Mariana Islands as a whole. Even if Sinlaku weakens considerably before it gets there (which is by no means given), significant typhoon impacts in the days ahead seem more likely than not.

The posts in this forum are NOT official forecasts and should not be used as such. They are just the opinion of the poster and may or may not be backed by sound meteorological data. They are NOT endorsed by any professional institution or STORM2K. For official information, please refer to products from the NHC and NWS.

[Yellow Evan]

Almost fully clear. Category 5 by 6z if it isn't already.

[Hayabusa]

Raw T#s near 8.0

2026APR12 020000 6.3 934.3 122.2 6.3 6.3 7.5 1.3T/6hr OFF OFF OFF OFF 2.65 -80.68 EYE 17 IR 64.9 10.02 -151.00 ARCHER HIM-9 16.8
2026APR12 022000 6.3 934.3 122.2 6.3 6.3 7.7 1.3T/6hr OFF OFF OFF OFF 11.44 -81.05 EYE 17 IR 64.9 10.10 -150.96 ARCHER HIM-9 16.8
2026APR12 031000 6.3 934.3 122.2 6.3 6.3 7.7 1.3T/6hr OFF OFF OFF OFF 16.04 -80.67 EYE 18 IR 64.9 10.10 -150.90 ARCHER HIM-9 16.8
2026APR12 033000 6.3 934.3 122.2 6.3 6.3 7.7 1.3T/6hr OFF OFF OFF OFF 18.81 -80.08 EYE 18 IR 64.9 10.10 -150.81 ARCHER HIM-9 16.7
2026APR12 040000 6.3 934.3 122.2 6.3 6.3 7.8 1.3T/6hr OFF OFF OFF OFF 18.95 -81.09 EYE 19 IR 64.9 10.15 -150.80 ARCHER HIM-9 16.7

[Sciencerocks]

[sasha_B]

Remarkably, Sinlaku's eye temperature on LWIR imagery has now passed 21°C, with little appreciable warming in the stable and symmetrical CDO. UW-CIMSS ADT CI remains 6.3 due to constraints, but raw T# is up to 7.8, which is fairly rare in any basin, at any time of year. Ragasa '25 didn't get there, and that was (officially) a 145 kt typhoon with empirically observed central pressure ≦900 hPa; Hurricane Milton's highest evaluated ADT# was 7.7.

Given that conditions are expected to remain conducive to intensification for at least 24h yet, the only factors holding this storm back for during that time will be internal dynamics (& MPI). Sinlaku has outperformed virtually all model forecasts with time to spare.

[MarioProtVI]

This is basically Mawar and Bolaven from three years ago wrapped into one. Would not rule out it actually getting that strong officially - can see a 155-160 kt peak here if all goes well, which it has been doing so far.

[mrbagyo]

Aren't they gonna send a recon into this?
This is a pretty significant threat to US installation