莫桑比克海峡热带气旋第5号“切内索”(08S.Cheneso) - 风眼开出 - JTWC:85KT

ygsj24

96S INVEST 230109 1800 7.6S 71.5E SHEM 20 1009

superstorm

EC等数值18Z支持一点程度发展，趋向马达加斯加。

superstorm

稍早风场显示东侧20—25Kt。

superstorm

GFS00Z调强，直扑马达加斯加。

8801Roy

数值报出不同幅度的东折……

8801Roy

中心狭长

renzhetegong

AWIO20 FMEE 101307

TROPICAL CYCLONE CENTER / RSMC LA REUNION / METEO-FRANCE

BULLETIN FOR CYCLONIC ACTIVITY AND SIGNIFICANT TROPICAL WEATHER IN
THE SOUTHWEST INDIAN OCEAN

DATE: 2023/01/10 AT 1200 UTC

PART 1:
WARNING SUMMARY:
Nil.

PART 2 :
TROPICAL WEATHER DISCUSSION:

The basin remains in a Monsoon trough (MT) pattern centered between 8oS and 10oS and between 50E and 80E. The associated convective activity is moderate and concentrated mainly on the equatorial side of the MT and south of Diego-Garcia near a low pressure circulation. The convection has become more compact around the low pressure system south of Diego-Garcia.

South of Diego-Garcia:

Current scatterometer observations allow us to see a closed but elongated shape circulation, centered around 9.8S/73.7E, confirmed by the satellite image.
The environmental conditions are mixed as to the strengthening of this vorticity precursor.

The latest ECMWF run (00 UTC) models a trade wind intrusion of dry air near the precursor, which may explain why this model tends to attenuate it, while GFS continues a good supply of moisture and strengthens the deepening of this precursor. Over the next weekend, the already good upper level divergence on the equatorial side could also strengthen on the polar side.
The different models (ECMWF/ARP/GFS) start to diverge from Thursday: ARP shows a new low over the Seychelles while ECMWF 00UTC develops another one between Algalega and Diego-Garcia. These different scenarios are reflected in the EPS and GEFS ensemble forecasts. The probabilities of development of these new lows into tropical storms seem to occur next week.
The scenario of development of the first precursor currently south of Diego-Garcia remains the predominant option but other alternative scenarios are to be considered, reflected by the dispersion in the models and runs.
The previous ECMWF runs agreed more with GFS, making the precursor deepen south of Diego-Garcia, but the last run (00UTC) moderates this deepening, which takes us to a still low probability (not moderate) of tropical storm formation.
During the next 5 days, there is a low risk of formation of a tropical storm from Friday south of Diego-Garcia.

NOTA BENE: The likelihood is an estimate of the chance of the genesis of a moderate tropical storm over the basin and within the next five days:

Very low:       less than 10%              Moderate:        30% to 60%        Very high:      over 90%
Low:             10% to 30%                  High:               60% to 90%

The Southwestern Indian Ocean basin extends from the equator to 40S and from the african coastlines to 90E.

renzhetegong

GFS新报认为将强势影响马达加斯加，高强度登陆东北部并纵贯全国。

renzhetegong

GEFS系集整体支持高强度

renzhetegong

ECMWF认为未来5天有明显东移，而后西南行进登陆马达加斯加