Equatorial Storm in the North Indian Ocean

[HURAKAN]

Invest 95A. is located around 0.6 N and part of its bands cross the Equator to the South Indian Ocean, the system has a fair look for development in the next 24 hours. If develops, it will be the closest storm to the Equator, taking the title from Typhoon Vamei.

27/2030 UTC 0.6N 69.7E T1.5/1.5 95A

[Hurricanehink]

Wow! And I thought Vamei was a once-in-a-lifetime event. This has some serious potential.

[Wnghs2007]

WOW. That looks very well organized. Im suprised it is not a depression atleast.

[Derek Ortt]

to maintain a closed circulation, the wind speed will need to increase to well over 100KT due to corolis parameters. Looking at the sat images, this may well happen in a couple of days.

Not entirely surprised since this is likely within a monsoon circulation and also wouldnt be surprised since the vorticity within the monsoon trough is allowing for the cross equatorial flow if this were to make it south of the equator

[Wnghs2007]

to maintain a closed circulation, the wind speed will need to increase to well over 100KT due to corolis parameters. Looking at the sat images, this may well happen in a couple of days.

Not entirely surprised since this is likely within a monsoon circulation and also wouldnt be surprised since the vorticity within the monsoon trough is allowing for the cross equatorial flow if this were to make it south of the equator

Wow. I did not know that Derek. Thanks again for providing great information. I looked forward to next years atlantic Hurricane season and your forecasts along with it.

[HurricaneBill]

So it could move south of the equator? But how would it be able to move counterclockwise? Wouldn't it get sheared apart if it suddenly had to switch to a clockwise motion?

Do you think equatorial storms have occurred before Vamei?

[Wnghs2007]

So it could move south of the equator? But how would it be able to move counterclockwise? Wouldn't it get sheared apart if it suddenly had to switch to a clockwise motion?

Do you think equatorial storms have occurred before Vamei?

Those are very good questions. I can answer 1 that there probally have been storms before Vamei. Because we have not been here for the whole life of the earth to see if its occured before and documented records only go back so far.

[Derek Ortt]

part of the circulation is CCW even south of the equator. The entire envelope is CCW. I would think that if it were to cross, it would continue to circulate CCW

[Wnghs2007]

part of the circulation is CCW even south of the equator. The entire envelope is CCW. I would think that if it were to cross, it would continue to circulate CCW

LOL....That would not destroy the Space time continum would it.

[Matt-hurricanewatcher]

This just proves if this where to develop on the 0 line. That we don't know every thing about tropical cyclones. Heck another south Atlantic hurricane could form this year...That to me looks like a tropical storm.

[Wnghs2007]

This just proves if this where to develop on the 0 line. That we don't know every thing about tropical cyclones. Heck another south Atlantic hurricane could form this year...That to me looks like a tropical storm.

Yes for all we know the SA could have 1,000 year cycles without development and then like 10-50 years it has 1 or 2 storms every other year. We just dont know.

[HURAKAN]

According to the JTWC the center is located at 1 North, which is still incredible.

[Wnghs2007]

According to the JTWC the center is located at 1 North, which is still incredible.

Thats still very cool. And incredible

[Matt-hurricanewatcher]

WTIO21 PGTW 280300
MSGID/GENADMIN/NAVPACMETOCCEN PEARL HARBOR HI/JTWC//
SUBJ/TROPICAL CYCLONE FORMATION ALERT 280251ZNOV2004//
RMKS/
1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN
150 NM EITHER SIDE OF A LINE FROM 1.0N1 70.0E7 TO 3.5N8 61.5E2
WITHIN THE NEXT 00 TO 24 HOURS. AVAILABLE DATA DOES NOT JUSTIFY
ISSUANCE OF NUMBERED TROPICAL CYCLONE WARNINGS AT THIS TIME.
WINDS IN THE AREA ARE ESTIMATED TO BE 25 TO 30 KNOTS. METSAT
IMAGERY AT 272330Z7 INDICATES THAT A CIRCULATION CENTER IS LOCATED
NEAR 1.0N1 69.0E5. THE SYSTEM IS MOVING WESTWARD AT 11 KNOTS.
2. REMARKS: THE AREA OF CONVECTION PREVIOUSLY LOCATED NEAR 01.6N7
70.9E6 IS NOW LOCATED NEAR 01.0N1 68.9E3, APPROXIMATELY 740 NM WEST-
SOUTHWEST OF COLOMBO, SRI LANKA. ANIMATED ENHANCED INFRARED SATELLITE
IMAGERY REVEALS INCREASING DEEP CONVECTION ORGANIZING OVER A LOW LEVEL
CIRCULATION CENTER (LLCC). UPPER LEVEL ANALYSIS INDICATES AN AREA OF
LOW VERTICAL WIND SHEAR AND GOOD DIFFLUENCE ALOFT. MAXIMUM SUSTAINED
SURFACE WINDS ARE ESTIMATED AT 25 TO 30 KNOTS. MINIMUM SEA LEVEL
PRESSURE IS ESTIMATED TO BE 1003 MB. THE POTENTIAL FOR THE DEVELOPMENT
OF A SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24 HOURS IS UPGRADED
TO GOOD.
3. THIS ALERT WILL BE REISSUED, UPGRADED TO WARNING OR CANCELLED BY
290300Z4.//
NNNN

That would be rare if this crossed over!

[HURAKAN]

THIS TROPICAL SYSTEM IS REALLY GETTING ITS ACT TOGETHER. ACCORDING TO NOGAPS, THIS SYSTEM WILL INTENSIFY AND MAKE LANDFALL IN YEMEN OR OMAN IN THE A WEEK OR SO.

[Matt-hurricanewatcher]

.5 north...With a 2.0/2.0 t number...

Say hello to a new record for tropical storms....

28/0230 UTC 0.5N 69.4E T2.0/2.0 95A -- Arabian Sea

[Hyperstorm]

Neat! I like the beauty of it. Doesn't it look magnificient? It reminds me of the beginnings of some the Atlantic storms this year.

On the other hand, I can't even imagine it moving south of the Equator and maintaining a CCW circulation. Derek, that coming from you, I really hope you're joking. That would be a meteorological improbability for all intended purposes. Coriolis/The force of the earth wouldn't allow it. Suppose you saw a CW circulation from this system south of the Equator, it will definitely not be a cloudy system any longer, but a high pressure system. Since any of the latter ones sound like a joke, then obviously the whole thing about moving south of the Equator, can't fit into my head.

Still, the fact that its feeder bands extend south of the equator, makes it a beauty that I don't want to miss...

[Derek Ortt]

monsoon spin.

we have been discussing this a lot at the office before this thing formed and we really would not be surprised to see something developing and moving cross equatorial. It would NOT be a high pressure since the surface pressures are being lowered due to the upper divergence, which takes mass from the column, causing the SLP to fall

all sat fixes show that the center is well south of where jtwc has it (closer to .5N.

if this would go south of the equator, corolis would be acting against the circulation; however, the contribuition due to the latitude is already .008726525 right now (only a little more than the omega term); thus, there is really no corolis present. The dominant feature is the monsoon circulation and will overcome any negative corolis

[Hyperstorm]

You have a point there, but until I see a research indicating this possibility, I will stand to what I know and have learned over the years...

[Derek Ortt]

no research is available because it has yet to have been documented to have occurred.

However, based upon the dynamical equations, this would seem to be possible, just with the corolis acting in the opposite direction, which would likely reduce the wind speed (unless I have made my quick calculation incorrectly)