WPAC: SINLAKU - Typhoon

[cycloneye]

PAGASA also up to TD.

[cycloneye]

12z GFS has a strong typhoon just south of Guam.

[Hayabusa]

WTPN21 PGTW 081800
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE FORMATION ALERT (INVEST 90W)//
RMKS/
1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN
120 NM EITHER SIDE OF A LINE FROM 8.6N 153.4E TO 9.3N 149.7E
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 18 TO 23 KNOTS. METSAT
IMAGERY AT 081730Z INDICATES THAT A CIRCULATION CENTER IS LOCATED
NEAR 9.2N 152.4E. THE SYSTEM IS MOVING NORTHWESTWARD AT 06 KNOTS.
2. REMARKS: THE AREA OF CONVECTION (INVEST 90W) PREVIOUSLY LOCATED NEAR
5.7N 153.4E IS NOW LOCATED NEAR 9.2N 152.4E, APPROXIMATELY 520 NM EAST-
SOUTHEAST OF GUAM. ANIMATED MULTISPECTRAL SATELLITE IMAGERY DEPICTS DEEP
CONVECTION OBSCURING THE BROAD LOW-LEVEL CIRCULATION CENTER (LLCC) WITH
CONVECTIVE BANDING WRAPPING ALONG THE SOUTHERN SEMICIRCLE. ENVIRONMENTAL
ANALYSIS REVEALS A FAVORABLE ENVIRONMENT FOR DEVELOPMENT WITH STRONG
EQUATORWARD OUTFLOW, LOW VERTICAL WIND SHEAR (10-15 KTS), AND WARM SEA
SURFACE TEMPERATURES (28-29 C). GLOBAL MODELS AGREE ON 90W SLOWLY
TRACKING GENERALLY WESTWARD AS IT CONSOLIDATES OVER THE NEXT 24-48
HOURS. MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 18 TO 23 KNOTS.
MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1005 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
091800Z.//
NNNN

[cycloneye]

WTPN21 PGTW 081800
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE FORMATION ALERT (INVEST 90W)//
RMKS/
1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN
120 NM EITHER SIDE OF A LINE FROM 8.6N 153.4E TO 9.3N 149.7E
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 18 TO 23 KNOTS. METSAT
IMAGERY AT 081730Z INDICATES THAT A CIRCULATION CENTER IS LOCATED
NEAR 9.2N 152.4E. THE SYSTEM IS MOVING NORTHWESTWARD AT 06 KNOTS.
2. REMARKS: THE AREA OF CONVECTION (INVEST 90W) PREVIOUSLY LOCATED NEAR
5.7N 153.4E IS NOW LOCATED NEAR 9.2N 152.4E, APPROXIMATELY 520 NM EAST-
SOUTHEAST OF GUAM. ANIMATED MULTISPECTRAL SATELLITE IMAGERY DEPICTS DEEP
CONVECTION OBSCURING THE BROAD LOW-LEVEL CIRCULATION CENTER (LLCC) WITH
CONVECTIVE BANDING WRAPPING ALONG THE SOUTHERN SEMICIRCLE. ENVIRONMENTAL
ANALYSIS REVEALS A FAVORABLE ENVIRONMENT FOR DEVELOPMENT WITH STRONG
EQUATORWARD OUTFLOW, LOW VERTICAL WIND SHEAR (10-15 KTS), AND WARM SEA
SURFACE TEMPERATURES (28-29 C). GLOBAL MODELS AGREE ON 90W SLOWLY
TRACKING GENERALLY WESTWARD AS IT CONSOLIDATES OVER THE NEXT 24-48
HOURS. MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 18 TO 23 KNOTS.
MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1005 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
091800Z.//
NNNN

[Hayabusa]

There's still no HWRF/HFSA runs for this system...

[mrbagyo]

[cycloneye]

There's still no HWRF/HFSA runs for this system...

They are running now. Guam in the crosshairs.





Hit to Guam as cat 4.

[DorkyMcDorkface]

Lot of expanse to this thing, seems primed to be a classic WPAC monster. Hoping Guam and the Marianas can escape this one...

[cycloneye]

A. TROPICAL DISTURBANCE (90W)

B. 08/2330Z

C. 8.8N

D. 152.0E

E. THREE/HIMAWARI-9

F. T2.0/2.0

G. IR/EIR/VIS/SSMIS

H. REMARKS...4.5/10 BANDING RESULTS IN A DT OF 2.5. MET AND PT=2.0. FT
BASED ON MET DUE TO IRREG/PULSING CONVECTION AND BANDING NOT CLR-CUT.

I. ADDL POSITIONS

08/2001Z 8.9N 152.5E SSMIS


...KONON

[Hurricane2022]

Now TD 04W!

[Hurricane2022]

Lot of expanse to this thing, seems primed to be a classic WPAC monster. Hoping Guam and the Marianas can escape this one...
https://i.imgur.com/WqWlGWy.gif

Looking too large. May become another bust like Fung-Wong last year with this beauty but terribly big structure.

[Yellow Evan]

Lot of expanse to this thing, seems primed to be a classic WPAC monster. Hoping Guam and the Marianas can escape this one...
https://i.imgur.com/WqWlGWy.gif

Looking too large. May become another bust like Fung-Wong last year with this beauty but terribly big structure.

This has way more time than Fung-Wong, although worse conditions early on with more easterly shear.

We won’t know the core size until it attempts to form one. Plenty of WPAC monsters start out broad.

[cycloneye]

[cycloneye]

First JTWC track is no fun for Guam as they will get the strongest quadrant.

[dexterlabio]

Lot of expanse to this thing, seems primed to be a classic WPAC monster. Hoping Guam and the Marianas can escape this one...
https://i.imgur.com/WqWlGWy.gif

Looking too large. May become another bust like Fung-Wong last year with this beauty but terribly big structure.

Not only did it deal with its large size but the VWS was also relentless with Fung-wong.

[cycloneye]

FORECAST DISCUSSION: TD 04W IS LOCATED IN A WEAK STEERING
ENVIRONMENT WITH A NORTHWEST EXTENSION OF A NEAR-EQUATORIAL RIDGE
(NER) TO THE EAST AND A STRONG SUBTROPICAL RIDGE (STR) CENTERED NEAR
LUZON. AFTER TAU 36, THE NER WILL BUILD AND INDUCE A MORE
NORTHWESTWARD MOTION. THE RIDGE WILL CONTINUE TO STRENGTHEN AND
GUIDE THE SYSTEM TOWARDS THE MARIANA ISLANDS THROUGH TAU 120. THERE
REMAINS SIGNIFICANT CHALLENGES IN THE EXTENDED FORECAST TRACK. TD
04W WILL ENCOUNTER COMPETING STEERING INFLUENCES: FROM THE EXTENSION
OF THE NER TO THE EAST AND THE STR TO THE WEST. A STRONGER NER WILL
PUSH THE SYSTEM MORE POLEWARD, WHILE A WEAKER RIDGE WILL LEAD TO A
MORE ZONAL TRACK. THE FORECAST CURRENTLY FAVORS THE MORE ZONAL
FORECAST VICE THE STRONGLY POLEWARD TRAJECTORY AS DEPICTED IN SOME OF
THE MODEL GUIDANCE. THE INTENSITY FORECAST IS MORE STRAIGHTFORWARD.
THE ENVIRONMENTAL CONDITIONS WILL BE HIGHLY FAVORABLE FOR CONTINUED
DEVELOPMENT. LOW VWS, PLENTIFUL MID-LEVEL MOISTURE, AND WARM SST
WILL FUEL INTENSIFICATION. THE FORECAST RATE OF DEEPENING INITIALLY
FOLLOWS THE CLIMATOLOGICAL RATE, GIVEN THE SIZE OF THE CIRCULATION.
MORE SIGNIFICANT INTENSIFICATION TOWARDS A 115 KT PEAK IS THEN
FORECAST AS THE INNER CORE BECOMES ESTABLISHED BY TAU 48. IT IS
IMPORTANT TO NOTE THAT THE WIND FIELD WILL EXTEND FAR OUT FROM THE
CENTER, MAKING FOR FAR-REACHING IMPACTS. THE FORECAST HOLDS THE
INTENSITY AT TAU 120 WITH LOW CONFIDENCE DUE TO THE EFFECTS OF A
SLIGHTLY WORSE ENVIRONMENT.

MODEL DISCUSSION: THE FORECAST TRACK LARGELY FOLLOWS THE
MULTI-MODEL CONSENSUS, WHICH IS CLOSELY ALIGNED WITH THE ECMWF AND THE
ECEPS MEAN. THE EXPERIMENTAL AI MODELS, ALONG WITH THE GALWEM AND
UKMET SUGGEST A MORE POLEWARD TRACK, TRACKING EAST OF THE MARIANAS,
WHILE THE GFS FAVORS A MORE ZONAL MOTION. THERE IS CONSIDERABLE
UNCERTAINTY IN THE ENSEMBLE MEMBERS, WITH OUTLIERS SPREAD ACROSS OVER
1200 NM, BUT GENERALLY FOCUSED ON THE SOUTHERN MARIANAS. CROSS-TRACK
SPREAD IN THE CONSENSUS MEMBERS INCREASES TO 420 NM BY TAU 120. ALL
MODELS DEPICT INTENSIFICATION THROUGH TAU 96, AFTER WHICH TIME A
COMBINATION OF LESS IDEAL ENVIRONMENTAL CONDITIONS AND INTERNAL STORM
DYNAMICS MAY CAP THE INTENSITY. THE INTENSITY FORECAST FOLLOWS THE
CONSENSUS THROUGH TAU 48 WITH MEDIUM CONFIDENCE AT ROUGHLY THE
CLIMATOLOGICAL RATE. FROM TAU 48 TO TAU 120, THE INTENSITY IS HEDGED
CLOSER TO THE COAMPS-TC AND HAFS-A MODELS WITH MEDIUM CONFIDENCE. THE
HAFS-A INTERPOLATION NOTABLY DEPICTS A PEAK INTENSITY OF 130 KTS WHEN
THE STORM WILL BE AT ITS CLOSEST APPROACH TO GUAM, HIGHLIGHTING THE
UNCERTAINTY IN THE PEAK INTENSITY AT TAU 96.

[xtyphooncyclonex]

Looks like we're seeing Sinlaku tonight.

How much ACE can she bring? I reckon more than any other storm last year. Seeing a big early-season boost now...

[cycloneye]

BULLETIN
Tropical Depression 04W Advisory Number 2
National Weather Service Tiyan GU WP042026
815 PM ChST Thu Apr 9 2026

...TROPICAL DEPRESSION 04W MOVING VERY SLOWLY WEST...

CHANGES WITH THIS ADVISORY
--------------------------
The Tropical Storm Watches for Fananu and Ulul in Chuuk State are
upgraded to a warning.

A Typhoon Watch is now in effect for Ulul in Chuuk State.

A Tropical Storm Watch is now in effect for Chuuk in Chuuk State.

WATCHES AND WARNINGS
--------------------
A Tropical Storm Warning is now in effect for Fananu and Ulul in
Chuuk State.

A Tropical Storm Warning means that tropical storm conditions,
including damaging winds of 39 to 73 mph, are expected within the
next 48 hours.

A Typhoon Watch is now in effect for Ulul in Chuuk State.

A Typhoon Watch means that typhoon conditions, including winds of
74 mph or greater, are possible within 48 hours.

A Tropical Storm Watch is in effect for Chuuk in Chuuk State.

A Tropical Storm Watch means that tropical storm conditions,
including damaging winds of 39 to 73 mph, are possible within the
next 48 hours.

SUMMARY OF 700 PM CHST...0900 UTC...INFORMATION
-----------------------------------------------
Location...8.1N 151.9E

About 40 miles southwest of Fananu
About 45 miles north of Chuuk
About 105 miles north-northwest of Losap
About 155 miles east-southeast of Ulul
About 205 miles east-northeast of Puluwat
About 610 miles southeast of Guam
About 640 miles southeast of Saipan
About 945 miles east of Yap

Maximum sustained winds...35 mph
Present movement...west...270 degrees at 3 mph

DISCUSSION AND OUTLOOK
----------------------
At 700 PM CHST...0900 UTC...the center of Tropical Depression 04W
was located near Latitude 8.1 degrees North and Longitude 151.9
degrees East. 04W is moving west at 3 mph. It is expected to
toward the northwest over the next few days with little change in
speed.

Maximum sustained winds have increased to 35 mph. 04W is forecast
to intensify over the next few days, possibly becoming a tropical
storm Friday and possibly becoming a typhoon Saturday.

Forecast track and wind speed probabilities graphics posted to WFO
Guam`s web page are currently unavailable. Please visit the Joint
Typhoon Warning Center web page at
https://www.metoc.navy.mil/jtwc/jtwc.html to see their latest
forecast track on TD 04W.

[cycloneye]

GUZ001-MPZ001>003-101145-
Guam-Rota-Tinian-Saipan-
934 PM ChST Thu Apr 9 2026

Tropical Depression 04W continues to organize north of Chuuk.
This system will continue to move very slowly northwest for
another 24 to 36 hours, before increasing forward speed as it
strengthens. The current forecasts have the system strengthening
into a typhoon or stronger, as it passes by Guam to the south. At
this time, at least Tropical Storm Force conditions are possible
for Guam and Typhoon Force conditions aren`t out of the question,
especially for southern portions of Guam. Current forecast tracks
from the Joint Typhoon Warning Center has the typhoon passing
south of Guam.

Additionally, locally heavy rainfall will develop. Initial
indications are for 10 to 15 inches of rainfall to develop for
Guam early next week, decreasing into the 4 to 8 inch range
further north towards Saipan. Locally higher amounts are probable.

WITH THAT SAID...this system doesn`t look to affecting the
Marianas until sometime in the Sunday afternoon through Monday
afternoon time frame, with possible deteriorating conditions
thereafter. NOW IS THE TIME to start preparations! Forecast
uncertainty in track and timing remains!

$$

Doll

[WaveBreaking]

I think Mawar (2023) could be a decent analog to this system based on the models showing TD 04:


- Form just before a string El Niño.

- Directly impact Guam from the SW.

- Peak W of the Philippines before going out to sea.

- Have a large TS-force wind field.