2021 NIO Cyclone Season

[TorSkk]

Very long-range GFS is showing some activity over the Arabian Sea which is also reflected in the new IMD outlook. We have not yet seen a cyclonic storm in either basin this season.

[TorSkk]

Potential is high for any TC that develops with above-average SSTs

[euro6208]

Not just the NIO but the SIO with possible twins on both side of the equator.

12z



18z

[DorkyMcDorkface]

Not just the NIO but the SIO with possible twins on both side of the equator.

12z

https://i.imgur.com/pLBPgyo.png

18z

https://i.imgur.com/u8hzvZk.png

https://i.imgur.com/Pw8mQKo.png

GFS spawns a significant WWB in the IO as a result. Don't see this everyday, although granted it's likely overdoing it:

It's on the Euro as well, albeit weaker:

[aspen]

Wow...I think it's safe to say the Indian Ocean is a ticking time bomb. These are among the highest SSTs and most intense model solutions I've ever seen for the basin.


The 902 mbar TC starts forming as early as this Friday, so there's a decent chance it's not a phantom.

[1900hurricane]

I bet we'll see some sort of development, though ultimate intensity is a big question mark. Partially due to time of year, I'm not too high on a SH twin, but it is possible. Kind of a similar situation to that observed with Surigae, where a TC is likely to develop with the aid of a strong westerly wind burst.

NIO sea surface temperatures are near their yearly maximum right now (the peak before the South Asian Monsoon switch) and are considerably above their average to boot. If a developing TC can take advantage of favorable conditions, it has the possibility to go big. We'll have to see though, speculating about the intensity of a future TC before the incipient disturbance is a pretty futile task, but there is potential there. Dry air is almost always a player in the Arabian Sea, so it'll be interesting to see how it might be offset by strong convergence and big -VP.

[Hayabusa]

lol 890 mb, Surigae was 888 mb

[doomhaMwx]

Today's 890mb cyclone on the GFS is probably the most intense modelled TC in the NIO ever. Hits Oman as a cat 5 and crosses into Saudi Arabia as a 960mb TC, lol .

[Kingarabian]

Fortunately there's very little support from the Euro and the CMC.

[mrbagyo]

[doomhaMwx]

DEMS-RSMC TROPICAL CYCLONES NEW DELHI DATED 10.05.2021

ARABIAN SEA:
BROKEN LOW AND MEDIUM CLOUDS WITH EMBEDDED INTENSE TO VERY INTENSE CONVECTION LAY OVER SOUTHWEST ARABIAN SEA ADJOINING INDIAN OCEAN BETWEEN LATITUDE 8.0N TO 2.0S LONGITUDE 50.0E TO 70.0E. SCATTERED LOW AND MEDIUM CLOUDS WITH EMBEDDED MODERATE TO INTENSE CONVECTION LAY OVER REST OF SOUTH ARABIAN SEA & MALDIEVES.
A CYCLONIC CIRCULATION EXTENDING UPTO 3.1 KM A.S.L. LIES OVER THE EQUATORIAL INDIAN OCEAN AND ADJOINING CENTRAL PARTS OF THE SOUTH ARABIAN SEA. IT IS LIKELY TO SHIFT EASTWARDS GRADUALLY AND UNDER ITS INFLUENCE A LOW PRESSURE AREA IS LIKELY TO FORM OVER SOUTHEAST ARABIAN SEA AND ADJOINING EQUATORIAL INDIAN OCEAN AROUND 14TH MAY. IT IS LIKELY TO BECOME MORE MARKED OVER THE SOUTHEAST ARABIAN SEA DURING THE SUBSEQUENT 48 HOURS.

REMARKS:
THE MADDEN JULIAN INDEX (MJO) CURRENTLY LIES IN PHASE 4 WITH AMPLITUDE CLOSE TO ONE. IT IS LIKELY TO CONTINUE IN THE SAME PHASE FOR THE NEXT 4-5 DAYS WITH GRADUAL REDUCTION IN AMPLITUDE. THE PHASE OF MJO IS CONDUCIVE FOR ENHANCED CONVECTION OVER THE ARABIAN SEA & BAY OF BENGAL DURING THE FORECAST PERIOD. THE AREA OF CONVECTION DEVELOPED OVER SOUTHWEST ARBIAN SEA & ADJOINING EQUATORIAL INDIAN OCEAN AND ALONG & OFF SOMALIA COAST AROUND 8TH MAY IS PERSISTING CURRENTLY OVER SOUTHWEST & ADJOINING SOUTHEAST ARABIAN SEA AND EQUATORIAL INDIAN OCEAN. THE CROSS EQUATORIAL FLOW IN THE NEAR EQUATORIAL BELT IS LIKELY TO GET ENHANCED DURING THE NEXT 5 DAYS. LOW LEVEL CONVERGENCE OF 20-30 X10 (-5) / S AND AN UPPER LEVEL DIVERGENCE OF THE ORDER OF 30 X 10 (-5) /S IS PREVAILING CURRENTLY OVER THE REGION OF CONVECTION. WIND SHEAR IS FAVOURING CONVECTION TO PERSIST AND IT IS LIKELY TO CONTINUE SO OVER THE REGION. NUMERICAL MODELS ARE INDICATING PROBABLE CYCLOGENESIS OVER BOTH HEMISPHERES IN THE EQUATORIAL BELT TOWARDS THE END OF THE FORECAST PERIOD. HENCE WE ARE ASSIGNING A 'LOW' PROBABILITY FOR CYCLOGENESIS OVER SOUTHEAST ARABIAN SEA AND ADJOINING EQUATORIAL INDIAN OCEAN TOWARDS THE END OF THE FORECAST PERIOD.

[Kingarabian]

00z Euro is in the middle of the GFS and CMC solutions:

[TorSkk]

For reference, the lowest pressure recorded in the basin is 920 hPa

[aspen]

I’m getting Surigae flashbacks with these continuously aggressive GFS runs.

The 06z GFS has a peak of 906 mbar and a Cat 4/5 landfall in the Arabian Peninsula. The time of development remains the same, with a Cat 1 being shown on Friday. Given the dry air always lurking around the Arabian Peninsula and all of the warm SSTs before it, I think it’s much more likely this system peaks well before it reaches Yemen/Oman. If the development time frame plays out like the GFS is saying, I would bet the system goes nuclear over the weekend.

[euro6208]

EURO strengthens the Arabian Sea system to 915 mb.

[doomhaMwx]

 https://twitter.com/jnmet/status/1393318383291146253

[doomhaMwx]

IMD now expects a disturbance to form over the Andaman Sea / BoB in the next few days and intensify to a cyclonic storm while approaching the coasts of northern BoB next week. Model support is high and like with TC Tauktae, background conditions are favorable under the influence of the MJO.

DEMS-RSMC TROPICAL CYCLONES NEW DELHI DATED 19.05.2021

BAY OF BENGAL:
SCATTERED LOW AND MEDIUM CLOUDS WITH EMBEDDED INTENSE TO VERY INTENSE CONVECTION LAY OVER SOUTH BAY OF BENGAL (BOB). SCATTERED LOW AND MEDIUM CLOUDS WITH EMBEDDED WEAK TO MODERATE CONVECTION LAY OVER NORTH BOB AND SOUTH ANDAMAN SEA.
A LOW PRESSURE AREA IS VERY LIKELY TO FORM OVER NORTH ANDAMAN SEA AND ADJOINING EASTCENTRAL BOB AROUND 22ND MAY, 2021. IT IS VERY LIKELY TO INTENSIFY GRADUALLY INTO A CYCLONIC STORM DURING SUBSEQUENT 72 HOURS. IT IS VERY LIKELY TO MOVE NORTHWESTWARDS AND REACH ODISHA - WEST BENGAL COASTS AROUND 26TH MAY EVENING.

PROBABILITY OF CYCLOGENESIS (FORMATION OF DEPRESSION) DURING NEXT 120 HRS:
24 HOURS 24-48 HOURS 48-72 HOURS 72-96 HOURS 96-120 HOURS
NIL NIL NIL LOW MODERATE