Download awio20 fmee 191222 tropical cyclone center / rsmc la reunion

AWIO20 FMEE 191222
TROPICAL CYCLONE CENTER / RSMC LA REUNION / METEO-FRANCE
BULLETIN FOR CYCLONIC ACTIVITY AND SIGNIFICANT TROPICAL WEATHER IN
THE SOUTHWEST INDIAN OCEAN
DATE: 2016/08/19 AT 1200 UTC
PART 1:
WARNING SUMMARY:
Nil.
PART 2 :
TROPICAL WEATHER DISCUSSION:
The basin is in a Near Equatorial Trough (NET) pattern axed along 4-5°S and east of 75°E. The
associated convective activity is locally strong but fluctuating and disorganized over a broad area
between the equator and 10°S and 75°E and the Indonesian coastlines. No suspect area is present
currently.
A low may develop within the NET between 75°E and 85°E on late Sunday or Monday.
Environmental conditions appear marginally conducive for cyclogenesis but some slow
development is possible. The negative factors include a persistent moderate north-easterly
constraint during most part of next week and strong dry air advection in the 600-800 hPa layers just
south of the equatorial westerlies that may disrupt the humidity convergence within the northern
sector (suggest by ECMWF and GFS). The favorable factors are: enhancement of the equatorial
westerlies to the north and the tradewinds in the southwestern quadrant (from Tuesday), combined
with good SST (28°C).
The system is expected to move little at first before a gradual eastwards or east-south-eastwards
forward motion under the main steering influence of the equatorial dynamics.
During the next 5 days, the likelihood of the development of a tropical depression is low to
moderate over the north-eastern part of our AoR from Monday to Wednesday.
NOTA BENE: The likelihood is an estimate of the chance of the genesis of a tropical depression
over the basin and within the next five days:
Very low:
Low:
less than 10%
10% to 30%
Moderate:
High:
30% to 50%
50% to 90%
Very high:
over 90%
The Southwestern Indian Ocean basin extends from the equator to 40S and from the african
coastlines to 90E.