west pacific Tropical Storm Mangkhut

[Somerset Squall]

The tenth tropical depression of the West Pacific season formed in the central South China Sea (SCS) yesterday, and has since become Tropical Storm Mangkhut, with winds estimated to be at 35kts by JMA. The track is very similar to TS Jebi's, but just further to the southwest. The storm is very broad in nature, with sprawling bands and little deep centralised convection. This suggests strengthening will be slow- however it's worth noting that Jebi looked very similar and managed to strengthen quite rapidly to near typhoon intensity as it approached Hainan Island last week. I'm not saying Mangkhut will do the same but there is a small chance of a similar strengthening episode, as shear is low and waters warm. The most likely outcome however, is for slow strengthening, perhaps to a mid-range tropical storm of about 45 or 50kt intensity. Ridging to the northeast and east if expected to guide Mangkhut to the northwest over the coming days, through the northern SCS into the Gulf Of Tonkin, roughly parallel to the coast of central and northern Vietnam. As Mangkhut is a large storm, rains will be felt through northern Vietnam, Hainan Island and the neighbouring Chinese coast. Mangkhut is expected to make landfall in northern Vietnam in a couple days time.

Edited August 6, 2013 by Somerset Squall

[Coast]

 

 

 

JTWC Advisory:

 

 

WTPN31 PGTW 061500

MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//

SUBJ/TROPICAL CYCLONE WARNING//

RMKS/

1. TROPICAL STORM 10W (MANGKHUT) WARNING NR 004    

   UPGRADED FROM TROPICAL DEPRESSION 10W

   01 ACTIVE TROPICAL CYCLONE IN NORTHWESTPAC

   MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE

   WIND RADII VALID OVER OPEN WATER ONLY

    ---

   WARNING POSITION:

   061200Z --- NEAR 15.9N 110.1E

     MOVEMENT PAST SIX HOURS - 320 DEGREES AT 17 KTS

     POSITION ACCURATE TO WITHIN 040 NM

     POSITION BASED ON CENTER LOCATED BY SATELLITE

   PRESENT WIND DISTRIBUTION:

   MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT

   WIND RADII VALID OVER OPEN WATER ONLY

   REPEAT POSIT: 15.9N 110.1E

    ---

   FORECASTS:

   12 HRS, VALID AT:

   070000Z --- 17.8N 108.5E

   MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT

   WIND RADII VALID OVER OPEN WATER ONLY

   RADIUS OF 034 KT WINDS - 040 NM NORTHEAST QUADRANT

                            035 NM SOUTHEAST QUADRANT

                            035 NM SOUTHWEST QUADRANT

                            035 NM NORTHWEST QUADRANT

   VECTOR TO 24 HR POSIT: 320 DEG/ 12 KTS

    ---

   24 HRS, VALID AT:

   071200Z --- 19.6N 106.9E

   MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT

   WIND RADII VALID OVER OPEN WATER ONLY

   RADIUS OF 034 KT WINDS - 040 NM NORTHEAST QUADRANT

                            035 NM SOUTHEAST QUADRANT

                            035 NM SOUTHWEST QUADRANT

                            040 NM NORTHWEST QUADRANT

   VECTOR TO 36 HR POSIT: 315 DEG/ 10 KTS

    ---

   36 HRS, VALID AT:

   080000Z --- 20.9N 105.4E

   MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT

   WIND RADII VALID OVER OPEN WATER ONLY

   DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER LAND

   VECTOR TO 48 HR POSIT: 295 DEG/ 07 KTS

    ---

   EXTENDED OUTLOOK:

   48 HRS, VALID AT:

   081200Z --- 21.5N 104.1E

   MAX SUSTAINED WINDS - 020 KT, GUSTS 030 KT

   WIND RADII VALID OVER OPEN WATER ONLY

   DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER LAND

    ---

REMARKS:

061500Z POSITION NEAR 16.4N 109.7E.

TROPICAL STORM 10W (MANGKHUT), LOCATED APPROXIMATELY 104 NM

EASTWARD OF DA NANG, VIETNAM, HAS TRACKED NORTHWESTWARD AT 17

KNOTS OVER THE PAST SIX HOURS. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 

061200Z IS 14 FEET. NEXT WARNINGS AT 062100Z, 070300Z, 070900Z AND 

071500Z.  //

NNNN

[Somerset Squall]

Mangkhut peaked at 40kts. The storm is making landfall in Northern Vietnam. Because of the large and sprawling nature of the storm, dangerous flooding rains are widespread across Vietnam, southern China, Hainan Island and even Thailand. Mangkhut should weaken now over land but even when the circulation dissipates, the rain will likely continue for several days.