BOB: Tropical Cyclone Komen

[Yellow Evan]

This is the one to watch.

[Alyono]

flooding rainfall will occur at a minimum. At worst, we could have an intense, slow moving TC producing days of tidal surge and heavy rainfall

[Alyono]

the environment is actually quite favorable. There is very low shear north of 20N, with a southward outflow jet

[Alyono]

looks close to a depression on visible

also, GFS now shows a significant TC as it moves it farther over the water

[Alyono]

officially a depression

http://www.rsmcnewdelhi.imd.gov.in/imag ... n/rsmc.pdf

[Alyono]

and JTWC does not even have it as a disturbance...

[Yellow Evan]

and JTWC does not even have it as a disturbance...

Probs two weak for them to Dvorak, and JTWC=Dvorak oretty much.

[Alyono]

been reports that the depression has already caused severe flooding for Bangladesh

[Alyono]

starting to organize fairly quickly. Wouldn't be surprised to see a TC by this time tomorrow

[jaguarjace]

AN AREA OF CONVECTION HAS PERSISTED NEAR 22.3N 90.6E,
APPROXIMATELY 69 NM WEST OF CHITTAGONG, BANGLADESH. ANIMATED
INFRARED SATELLITE IMAGERY DEPICTS A BROAD AREA OF LOW PRESSURE
ALONG THE BANGLADESH COASTLINE, WITH CONVECTIVE BANDING OVER
THE BAY WRAPPING INTO THE CENTER. THE CONVECTIVE ORGANIZATION
HAS IMPROVED SIGNIFICANTLY OVER THE PAST 12 HOURS AND THE 850 MB
VORTICITY SIGNATURE IS BECOMING MORE SYMMETRIC. A 261533Z ASCAT
PARTIAL PASS REVEALED 30 KNOT WINDS UNDERNEATH THE DEEP CONVECTION.
THIS CONVECTION IS BEING ENHANCED BY STRONG UPPER LEVEL DIFFLUENCE;
HOWEVER, FUTHER ORGANIZATION IS HAMPERED BY MODERATE TO STRONG
VERTICAL WINDSHEAR (20-30 KNOTS) IN ADDITION TO FRICTIONAL EFFECTS
WHILE THE LOW LEVEL CIRCULATION CENTER REMAINS OVER LAND. NUMERICAL
GUIDANCE SOLUTIONS DEPICT THIS DISTURBANCE TRACKING VERY SLOWLY
WESTWARD ALONG THE COASTLINE INTO INDIA OVER THE NEXT THREE DAYS.
IF THE DISTURBANCE WERE TO TRACK JUST SLIGHTLY FURTHER SOUTH,
THE WARM WATERS OF THE BAY AND GOOD OUTFLOW MAY ALLOW FOR RAPID
DEVELOPMENT OF A TROPICAL CYCLONE. MAXIMUM SUSTAINED SURFACE WINDS
ARE ESTIMATED AT 25 TO 30 KNOTS. MINIMUM SEA LEVEL PRESSURE IS
ESTIMATED TO BE NEAR 997 MB. THE POTENTIAL FOR THE DEVELOPMENT OF
A SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24 HOURS IS MEDIUM.

[wxman57]

Satellite indicates that the center remains inland, located just to the east of Calcutta.

[Alyono]

looks like its around 22N, 89.8E. Should move offshore in 24 hours or so according to the guidance

That said, ASCAT is indicating the center is closer to 90.5E

[euro6208]

THE AREA OF CONVECTION PREVIOUSLY LOCATED NEAR 22.3N 90.6E
IS NOW LOCATED NEAR 22.5N 90.1E, APPROXIMATELY 95 NM WEST OF
CHITTAGONG, BANGLADESH. RECENT ANIMATED MULTISPECTRAL SATELLITE
IMAGERY SHOWED A PARTIALLY EXPOSED AND WELL-DEFINED LOW LEVEL
CIRCULATION CENTER (LLCC) THAT REMAINS OVER LAND. ANIMATED ENHANCED
INFRARED SATELLITE IMAGERY SHOWS ALL SIGNIFICANT CONVECTION IS
LOCATED ALONG THE PERIPHERY OF THE LLCC AND WITHIN THE FORMATIVE
BANDING OVER THE BAY OF BENGAL. A 271242Z SSMIS 91GHZ MICROWAVE
IMAGE SHOWS FRAGMENTED CONVECTION WITHIN THE FORMATIVE BANDING. AN
OLDER ASCAT PASS SHOWED 25 TO 30 KNOT WINDS OVER THE BAY OF BENGAL,
WHICH IS BEING ENHANCED BY THE SOUTHWEST MONSOON, AND LIGHTER WINDS
AS YOU APPROACH THE COASTLINE. IN ADDITION, OBSERVATIONS IN
BANGLADESH SHOW WEAK (5-10 KNOT) WINDS NEAR THE CENTER. UPPER LEVEL
ANALYSIS INDICATES A MARGINAL ENVIRONMENT WITH STRONG NORTHEASTERLY
FLOW ENHANCING THE CONVECTIVE BANDING BUT ALSO CREATING 20 TO 30
KNOT VERTICAL WIND SHEAR. DYNAMIC MODEL GUIDANCE INDICATES THAT THE
DISTURBANCE WILL REMAIN QUASI-STATIONARY OVER THE NEXT TWO DAYS
PRIOR TO TRACKING WESTWARD INTO INDIA. IF THE DISTURBANCE WERE TO
TRACK FURTHER SOUTH, THE WARM WATERS OF THE BAY AND GOOD OUTFLOW MAY
ALLOW FOR RAPID DEVELOPMENT OF A TROPICAL CYCLONE. MAXIMUM SUSTAINED
SURFACE WINDS ARE ESTIMATED AT 25 TO 30 KNOTS. MINIMUM SEA LEVEL
PRESSURE IS ESTIMATED TO BE NEAR 997 MB. THE POTENTIAL FOR THE
DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24
HOURS REMAINS MEDIUM.

[Alyono]

may be a cyclone now based upon satellite imagery and earlier data

[Alyono]

clearly offshore and intensifying now

[jaguarjace]

[Alyono]

if this is in fact closer to 20N, this will be the horrific thing the UKMET was forecasting last week.

[Alyono]

http://www.ucanews.com/news/at-least-7- ... oods/73987

7 dead in Bangladesh already. Also saw 17 dead in Myanmar. I expect these numbers to increase greatly

[Alyono]

40 kts on ASCAT-B. A bit higher than the ASCAT-A

Not sure why there is not a TCFA out from JTWC or this is not at least a deep depression as per IMD

[euro6208]

WTIO21 PGTW 281930
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE FORMATION ALERT//
RMKS/
1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN
A 125 NM RADIUS OF 21.1N 91.1E WITHIN THE NEXT 06 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 281800Z INDICATES THAT A
CIRCULATION CENTER IS LOCATED NEAR 21.1N 91.1E. THE SYSTEM IS
MOVING EASTWARD AT 05 KNOTS.
2. REMARKS: THE AREA OF CONVECTION PREVIOUSLY LOCATED NEAR 21.5N
90.1E IS NOW LOCATED NEAR 21.1N 91.1E, APPROXIMATELY 85 NM SOUTH-
SOUTHWEST OF CHITTAGONG, BANGLADESH. ANIMATED ENHANCED INFRARED
SATELLITE IMAGERY SHOWS A BROAD AREA OF CYCLONIC TURNING WITH
CONVECTION BUILDING OVER THE LOW LEVEL CIRCULATION CENTER (LLCC). A
281454Z ASCAT PASS SHOWED A DEFINED CIRCULATION WITH 30 KNOT WINDS
WRAPPING AROUND THE NORTHERN SEMI-CIRCLE AND STRONGER GRADIENT WINDS
TO THE SOUTH ENHANCED BY THE SOUTHWEST MONSOON. UPPER LEVEL ANALYSIS
INDICATES A MARGINAL ENVIRONMENT WITH STRONG NORTHEASTERLY FLOW
PROVIDING GOOD EQUATORWARD OUTFLOW; HOWEVER, A TUTT LOCATED TO THE
NORTHEAST IS ADVECTING DRY AIR AND SUBSIDENCE OVER THE NORTHERN
PORTION OF THE SYSTEM. VERTICAL WIND SHEAR IS LOW (5-10 KNOT) ALONG
THE BANGLADESH COASTLINE BUT INCREASES TO MODERATE LEVELS (20-25
KNOT) FURTHER SOUTH INTO THE BAY OF BENGAL. SEA SURFACE TEMPERATURES
(SSTS) ABOVE 31 CELSIUS ARE VERY CONDUCIVE FOR FURTHER DEVELOPMENT.
DYNAMIC MODEL GUIDANCE INDICATES THAT THE DISTURBANCE WILL REMAIN
QUASI-STATIONARY OVER THE NEXT 24 TO 36 HOURS AND HAS THE POTENTIAL
TO FURTHER DEVELOP INTO A TROPICAL CYCLONE. MAXIMUM SUSTAINED
SURFACE WINDS ARE ESTIMATED AT 25 TO 30 KNOTS. MINIMUM SEA LEVEL
PRESSURE IS ESTIMATED TO BE NEAR 995 MB. DUE TO THE DEFINED LLCC IN
ASCAT AND THE VERY WARM SSTS, THE POTENTIAL FOR THE DEVELOPMENT OF A
SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24 HOURS IS HIGH.
3. THIS ALERT WILL BE REISSUED, UPGRADED TO WARNING OR CANCELLED BY
291930Z.//
NNNN