WPAC, Indian Ocean, and Southern Hemisphere Tropical Cyclones

[Chinook]

Pretty interesting Youtube video

 

[vortex95]

Arnab looks quite good as it approaches land.  I bet it is 125-130 kt given it pinhole eye and small size (115 kt at 06z).

One things that has bugged me w/ JTWC wind fcst once a system is inland.  Look at the 28/06z fcst position on the graphic attached.  It is a good 30 nm inland by that point, and still 100 kt sustained?  That is unrealistic given how coefficient of friction over land is much higher over than water, so winds drop very quickly.  And the TC will be quickly weakening at the same time.  And still 65 kt sustained 12 hr later farther inland?  No way.

Now, for this two fcst positions, 100 kt and 65 kt *gusts* at these times are reasonable, but that's a huge difference in sensible wx than these sustained values!

Look at the HAFS-A fcst for landfall and when it is just inland.  The model shows how big the effects of land friction are!

[vortex95]

It seems the disturbance NE of Arnab (90B) has quite the organization and IMHO is a minimal TS as it is about to make landfall as I type this.

 

3 microwave passes since 27/2000z clearly show a well-defined center w/ impressive curved banding (attached).  Nascent CDO w/ cloud tops as cold as -87 C and a fairly quick NW motion would support minimal TS-force winds.

Radar shows a well-defined system at landfall.

Look a the amended 03z TWO update from JTWC.  See below.

 

"Dissipated?"  I find that disingenuous and a lie.  Yes, I know JTWC is not the RSMC and IMD takes care of it, but it just goes to show the issues outside NHC's AOR w/ "shorties" not counted still these days.  And sometimes they are not just weaksystems these shorties!  Either way, locally there would be sig impacts where 90B makes landfall.  Is that not important?

 

If this was NHC AOR, they would have declared it a TC, and I would agree 100%.  It is what it is!

 

ABIO10 PGTW 280300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/SIGNIFICANT TROPICAL WEATHER ADVISORY FOR THE INDIAN OCEAN 
REISSUED/280300Z-281800ZOCT2026//
REF/A/MSG/JOINT TYPHOON WRNCEN PEARL HARBOR HI/280152ZOCT2026//
AMPN/REF A IS A TROPICAL CYCLONE WARNING.//
RMKS/
1. NORTH INDIAN OCEAN AREA (MALAY PENINSULA WEST TO COAST OF AFRICA):
   A. TROPICAL CYCLONE SUMMARY:
      (1) AT 28OCT26 0000Z, TROPICAL CYCLONE 02B (ARNAB) WAS LOCATED 
NEAR 16.2N 81.6E, APPROXIMATELY 543 NM SOUTHWEST OF KOLKATA, INDIA, AND 
HAD TRACKED SOUTHWARD AT 02 KNOTS OVER THE PAST SIX HOURS. MAXIMUM 
SUSTAINED SURFACE WINDS WERE ESTIMATED AT 65 KNOTS GUSTING TO 80 KNOTS. 
SEE REF A (WTIO31 PGTW 280300) FOR FURTHER DETAILS.
      (2) NO OTHER TROPICAL CYCLONES.
   B. TROPICAL DISTURBANCE SUMMARY:
      (1) THE AREA OF CONVECTION (INVEST 90B) PREVIOUSLY LOCATED NEAR 
17.7N 85.1E HAS DISSIPATED AND IS NO LONGER SUSPECT FOR THE DEVELOPMENT 
OF A SIGNIFICANT TROPICAL CYCLONE IN THE NEXT 24 HOURS.
      (2) NO OTHER SUSPECT AREAS.
   C. SUBTROPICAL SYSTEM SUMMARY: NONE.
2. SOUTH INDIAN OCEAN AREA (135E WEST TO COAST OF AFRICA):
   A. TROPICAL CYCLONE SUMMARY: NONE.
   B. TROPICAL DISTURBANCE SUMMARY: NONE.
   C. SUBTROPICAL SYSTEM SUMMARY: NONE.
3. JUSTIFICATION FOR REISSUE: DISSIPATED AREA IN PARA. 1.B.(1).//
NNNN