Bay of Bengal: Severe Cyclonic Storm AILA (02B)

[cycloneye]

ABIO10 PGTW 231800
MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC//
SUBJ/SIGNIFICANT TROPICAL WEATHER ADVISORY FOR THE INDIAN
/OCEAN/231800Z-241800ZMAY2009//
RMKS/
1. NORTH INDIAN OCEAN AREA (MALAY PENINSULA WEST TO COAST OF AFRICA):
A. TROPICAL CYCLONE SUMMARY: NONE.
B. TROPICAL DISTURBANCE SUMMARY:
(1) THE AREA OF CONVECTION PREVIOUSLY LOCATED NEAR 16.5N 88.2E
IS NOW NEAR 18.5N 88.9E, APPROXIMATELY 245 NM SOUTH OF KOLKATA,
INDIA. ANIMATED WATER VAPOR SATELLITE IMAGERY INDICATES A CONSOLI-
DATING SYSTEM WITH DEEP CONVECTIVE BANDING OVER THE SOUTHERN SEMI-
CIRCLE AND FORMATIVE BANDING ON THE NORTHEAST QUADRANT OF A
PARTIALLY EXPOSED LOW-LEVEL CIRCULATION CENTER (LLCC). A 231220Z
QUIKSCAT IMAGE SUPPORTS A 25-30 KNOT LLCC WITH STRONGER WINDS
EMBEDDED IN THE AREAS OF INTENSE CONVECTION. THIS LLCC HAS BECOME
STRONGER AND MORE DEFINED OVER THE PAST 12 HOURS. THE SYSTEM IS
LOCATED WITHIN A FAVORABLE ENVIRONMENT WITH GOOD EQUATORWARD
OUTFLOW AND DEVELOPING POLEWARD OUTFLOW, ENHANCED BY AN UPPER-LEVEL
SHORTWAVE TROUGH OVER NORTHERN INDIA. THE LLCC IS ALSO LOCATED OVER
VERY WARM SST AND HIGH OCEAN HEAT CONTENT WITH VERY HIGH TOTAL
PRECIPITABLE WATER VALUES. ALTHOUGH DEEP CONVECTION IS CURRENTLY
LACKING OVER THE LLCC, THE SYSTEM IS EXPECTED TO ORGANIZE QUICKLY IN
THE NEXT 06-12 HOURS. ADDITIONALLY, POLEWARD OUTFLOW IS FORECAST TO
IMPROVE AS THE MIDLATITUDE TROUGH DEEPENS OVER INDIA. MAXIMUM
SUSTAINED SURFACE WINDS ARE ESTIMATED AT 25 TO 30 KNOTS AND MINIMUM
SEA LEVEL PRESSURE AT 1000 MB. THE POTENTIAL FOR THE DEVELOPMENT OF
A SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24 HOURS REMAINS GOOD.

[Derek Ortt]

wasnt expecting this to get this large

behaving as I expected, consolidating during the last 24 hours... it is now primed to go quickly. Distressed that there is a trough to its west... means even faster intensification

[KWT]

Yep its certainly a big system, just got to hope that means it takes longer to spin itself up in this case but who knows, even if it doesn't ramp up like expected, its in an area where a large cyclone will still cause big issues.

Stills SST's are very toasty around it and models are agressive with it as well.

[cycloneye]

Its cranking up bigtime and that is bad news for all in that area.

[RL3AO]

If I didn't know better, I might think this is a tropical cyclone...

[Derek Ortt]

if I were making a forecast on this, it owuld be something like the following (note... please don't pay close attention to the coordinates, as I am home and don't have good access to all the models or the initial position

Initial: 16.2N 86.8E 40KT
12 Hour: 16.8N 86.8E 45KT
24 Hour: 17.5N 86.8E 60KT
36 Hour: 19.5N 86.8E 80KT
42 Hour: 21.0N 86.5E 90KT (near land)

[KWT]

Yeah I really can't see how this hasn't been upgraded yet to be honest.

90kts would be a very severe hit for this part of the world, if it can ramp up rapidly enough the scary thing is thats quite possible....

[HurricaneRobert]

I don't think it will be much greater than tropical storm strength. It will have a difficult time strengthening with all the land around it.

[Derek Ortt]

the land will not hinder this... almost no chance of land hindering intensification given these dynamics

[Normandy]

the land will not hinder this... almost no chance of land hindering intensification given these dynamics

How close is it suppose to get to the coast? What is the current forecast Re: track? NE motion?

[Derek Ortt]

primarily to the north and is should make landfall on Monday

what should let it blow up very quickly is an upper trough to its west. It is already creating that second outflow jet. Dual outflow jets over warm waters with a very moist environment means one thing

[Derek Ortt]

and let us remember, if this does come in as a cat 2 as i suspect, due to its size (it takes up the entire BOB), and the shallow waters of the river deltas, we could see a tidal surge over 20 feet. Remember what Ike did

[Derek Ortt]

how is this not classified as more than a depression?

http://www.ssd.noaa.gov/mtsat/flt/t1/loop-avn.html. This looks like a 35KT storm on sat imagery and with the QS, we know it is higher

[Derek Ortt]

http://www.ssd.noaa.gov/PS/TROP/tdpositions.html

T 2.5 as of 6 hours ago... looks more like a 3.0 now

[CrazyC83]

There is no reason to go less than 50 kt at this point (using QuikSCAT, it may be a bit higher but I'll stick with that for now). Pressure probably around 986mb - observations at two stations are 996 and 997 far away so the background pressure is probably lower than normal.

[wyq614]

Upgraded to 02B now

[HURAKAN]

[Derek Ortt]

where do you see the upgrade to 02B? NRL is still 98B

[HURAKAN]

DEMS–RSMC TROPICAL CYCLONES NEW DELHI 23-05-2009

Tropical weather outlook for north Indian ocean (The bay of Bengal and Arabian sea) valid for next 24 hours issued at 2100 utc OF 23 MAY, 2009 based on 1800 UTC of 23 MAY, 2009 (.)

THE DEPRESSION OVER WEST CENTRAL BAY OF BENGAL MOVED NORTHEASTWARDS AND LAY CENTRED AT 1800 UTC OF TODAY, THE 23RD MAY 2009 OVER WEST CENTRAL & ADJOINING EAST CENTRAL BAY OF BENGAL NEAR LAT. 17.00 N AND LONG. 88.50 E, ABOUT 430 KM SOUTHEAST OF PARADIP (42976), 530 KM SOUTH SOUTHEAST OF SAGAR ISLAND (42903) AND 590 KM SOUTH-SOUTHWEST OF KHEPUPARA (41984).

SATELLITE IMAGeRY INDICATES PERSISTANT ORGANISED CONVECTION. THE INTENSITY OF THE SYSTEM IS T1.5. ASSOCIATED BROKEN INTENSE TO VERY INTENSE CONVECTION OBSERVED OVER AREA BETWEEN LAT. 11.00 N AND 18.50 N AND WEST OF LONG. 90.00 E. THE LOWEST CLOUD TOP TEMPERATURE (CTT) DUE TO CONVECTION IS AROUND -700C AROUND THE SYSTEM.

sustained maximum SURFACE wind speed is estimated to be about 25 KNOTS. the state of the sea is rough to VERY rough around the system centre. the estimated CENTRAL pressure is about 996 hpa.

VERTICAL WIND SHEAR OF HORIZONTAL WIND OVER THE REGION IS AROUND 15-20 KNOTS. THE SYSTEM LIES VERY CLOSE TO THE UPPER TROPOSPHERIC RIDGE, WHICH ROUGHLY RUNS ALONG 170N IN ASSOCIATION WITH THE ANTICYCLONIC CIRCULATION OVER EAST CENTRAL BAY LOCATED TO THE EAST-NORTHEAST OF THE SYSTEM CENTRE. THERE IS A FEEBLE UPPER TROPOSPHERIC TROUGH IN WESTERLIES ROUGHLY RUNNING ALONG 800 E TO THE NORTH OF 200 N. SEA SURFACE TEMPRATURES ARE ALSO FAVOURABLE FOR INTENSIFICATION AS IT IS 0.50 TO 1.00 C ABOVE NORMAL. MAJORITY OF NWP MODELS ALSO SUGGEST INTENSIFICATION OF THE SYSTEM AND LANDFALL OVER WEST BENGAL AND ADJOINING BANGLADESH COAST.

CONSIDERING ALL THE ABOVE, THE SYSTEM IS LIKELY TO INTENSIFY FURTHER AND MOVE IN A NEAR NORTHERLY DIRECTION AND CROSS WEST BENGAL-BANGLADESH COAST NEAR 890 E (ABOUT 100 KM EAST OF SAGAR ISLAND) BETWEEN 1200 AND 1500 UTC OF 25TH MAY 2009.

[Derek Ortt]

The IMD... not surprised they did not consider the QS...