BoB: Very Severe Cyclonic Storm SIDR

[Derek Ortt]

the only thing official about the IMD is that their estimate is officially comical

[CrazyC83]

the only thing official about the IMD is that their estimate is officially comical

I agree, 986mb in a Cat 3 is unrealistic even in the Atlantic with its higher ambient pressures (that would normally support a Cat 1 at best). Even in an environment of super-high ambient pressures, 986 would equate to about 75-80 kt. The 992mb earlier was even more laughable - that typically supports a tropical storm, maybe a weak Cat 1.

Typically, a storm of 105-110 kt winds in the Atlantic supports a pressure in the 945-957 range. In the Indian Ocean ambient pressures are lower so it should be lower still - probably in the 930s or low 940s.

[HURAKAN]

Eye begins to clear.

[Crostorm]

[RattleMan]

90kt now:

DEMS-RSMC TROPICAL CYCLONES NEW DELHI DATED 13-11-2007

TROPICAL STORM “SIDR” ADVISORY NO. EIGHT ISSUED AT 0300 UTC OF 13 NOVEMBER, 2007.

THE VERY SEVERE CYCLONIC STORM “SIDR” OVER SOUTHEAST BAY OF BENGAL MOVED NORTHWESTWARDS AND LAY CENTRED AT 0000 UTC OF 13TH NOVEMBER 2007 OVER SOUTHEAST BAY OF BENGAL NEAR LAT. 12.00 N AND LONG 89.50 E, ABOUT 350 KM WEST OF PORT BLAIR (43333 ).

ESTIMATED CENTRAL PRESSURE: 968 HPA MOVEMENT NORTHWESTERLY 8 KT RPT 8 KT DURING PAST 6 HOURs. THE “EYE” IS VISSIBLE IN SATELLITE IMAGERIES.CURRENT INTENSITY: T5.0 RPT T5.0. MAXIMUM SUSTAINED SURFACE WIND SPEED 90-100 KTS AROUND THE STROM CENTRE. SEA PHENOMENAL.

FORECAST: THE STORM IS LIKELY TO MOVE IN A NORTHWESTERLY DIRECTION AT ABOUT 6 KT. INTENSIFY T6.0 RPT T6.0 WITH WINDS OF 115 KT GUSTING TO 130 KT NEAR THE CENTRE OF THE STORM AT 0000 UTC OF 14TH NOVEMBER 2007.

[HURAKAN]

Back to excellent.

[Sanibel]

950 range, intensifying to 115KTS sounds reasonable. The storm could have a perfect overhead and look stronger than it is. On the other hand the satellite and IR look like similar storms in the category 3-5 range.

[wxmann_91]

Watch for the dry air to its west. IR loops show cloud tops rapidly warming in the western semicircle of the storm. Latest PW analysis shows some pretty dry air advancing toward SIDR - may put a dent in the storm if trends continue.

[CrazyC83]

UW - CIMSS
ADVANCED DVORAK TECHNIQUE
ADT-Version 7.2.1
Tropical Cyclone Intensity Algorithm

----- Current Analysis -----
Date : 13 NOV 2007 Time : 060000 UTC
Lat : 12:18:00 N Lon : 89:30:00 E

CI# /Pressure/ Vmax
6.2 / 921.8mb/119.8kt

6hr-Avg T# 3hr-Avg T# Adj T# Raw T#
5.6 5.6 5.5 4.6

Latitude bias adjustment to MSLP : +0.0mb

Center Temp : -72.9C Cloud Region Temp : -69.7C

Scene Type : UNIFORM CDO CLOUD REGION

Positioning Method : FORECAST INTERPOLATION

Ocean Basin : INDIAN
Dvorak CI > MSLP Conversion Used : PACIFIC

Tno/CI Rules : Constraint Limits : 0.7T/6hr
Weakening Flag : ON
Rapid Dissipation Flag : FLAG

****************************************************

CIMSS thinks this is about to rapidly weaken...

[P.K.]

The previous forecast was only up to 115kts as opposed to 125kts.

DEMS-RSMC TROPICAL CYCLONES NEW DELHI DATED 13-11-2007

TROPICAL STORM “SIDR” ADVISORY NO. NINE ISSUED AT 0600 UTC OF 13 NOVEMBER, 2007.

THE VERY SEVERE CYCLONIC STORM “SIDR” OVER SOUTHEAST BAY OF BENGAL REMAINED PRACTICALLY STATIONARY AND LAY CENTRED AT 0300 UTC OF 13TH NOVEMBER 2007 OVER SOUTHEAST BAY OF BENGAL NEAR LAT. 12.00 N AND LONG 89.50 E, ABOUT 350 KM WEST OF PORT BLAIR (43333 ).

ESTIMATED CENTRAL PRESSURE: 968 HPA. THE “EYE” IS VISSIBLE IN SATELLITE IMAGERIES. INTENSE TO VERY INTENSE CONVECTIVE CLOUDS ARE SEEN AROUND THE SYSTEM CENTRE. CURRENT INTENSITY: T5.0 RPT T5.0. MAXIMUM SUSTAINED SURFACE WIND SPEED 90-100 KTS AROUND THE STROM CENTRE. SEA: PHENOMENAL.

FORECAST: THE STORM IS LIKELY TO MOVE IN A NORTHWESTERLY DIRECTION AT ABOUT 6 KT. INTENSIFY T6.0 RPT T6.0 WITH WINDS OF 125 KT GUSTING TO 140 KT NEAR THE CENTRE OF 2THE STORM AT 0300 UTC OF 14TH NOVEMBER 2007.

[wxmann_91]

Watch for the dry air to its west. IR loops show cloud tops rapidly warming in the western semicircle of the storm. Latest PW analysis shows some pretty dry air advancing toward SIDR - may put a dent in the storm if trends continue.

It seems that that is occurring right now... western side looks really anemic now and the eye has become slightly less defined.

[Squarethecircle]

Eye filled by clouds now actually, although the storm still looks fairly healthy. What are the T-numbers now, again?

[badkhan]

Is there anything the WMO can do (better yet will do) about the IMD? Like replace them with a new RSMC (don't know if there is anyone else out there)?

Pakistan Meteorological Department can do the job. Its advisories are pretty accurate for Arabian sea. PMD had started issuing advisories on Yemyin from June 22, when it was deep depression in the Bay of Bengal, also the frequency of advisories was much higher in comparison (advisories were issued in every 2-3 hours).
But whether it can do the job for Bay of Bengal is questionable. So i guess we are stuck with IMD.

[RL3AO]

Uh oh.

[P.K.]

The official forecast is a bit higher than the JTWC one posted above taking this to a super cyclonic storm.

TROPICAL CYCLONE ADVISORY

RSMC-TROPICAL CYCLONES, NEW DELHI

TROPICAL STORM “SIDR” ADVISORY NO. ELEVEN ISSUED AT 1200 UTC OF 13TH NOVEMBER, 2007. THE VERY SEVERE CYCLONIC STORM “SIDR” OVER SOUTHEAST BAY OF BENGAL MOVED NORTHWARDS AND LAY CENTRED AT 0900 UTC OF 13TH NOVEMBER 2007 OVER SOUTHEAST AND ADJOINING CENTRAL BAY OF BENGAL NEAR LAT. 13.00 N AND LONG 89.50 E, ABOUT 380 KM WEST-NORTHWEST OF PORT BLAIR (43333 ).

ESTIMATED CENTRAL PRESSURE: 964hPa.

THE “EYE” IS VISIBLE IN SATELLITE IMAGERIES. INTENSE TO VERY INTENSE CONVECTIVE CLOUDS ARE SEEN AROUND THE SYSTEM CENTRE.

CURRENT INTENSITY: T5.0 RPT T5.0.

MAXIMUM SUSTAINED SURFACE WIND SPEED IS 90-100 KTS AROUND THE STORM CENTRE.


SEA: VERY ROUGH TO HIGH.


FORECAST: THE STORM IS LIKELY TO MOVE IN A NORTH-NORTHWESTERLY DIRECTION AT ABOUT 06 KT.


INTENSITY T6.0 RPT T6.0 WITH WINDS OF 125 KTS GUSTING TO 140 KTS NEAR THE CENTRE OF THE STORM AT 0900 UTC OF 14TH NOVEMBER 2007.

[Squarethecircle]

If this thing intensifies to 125 knots, then it will probably retain huge storm surge and category four winds until landfall. However, it looks like there could be a possibility of de-intensification in the not to distant future. We can only hope.

[hcane27]

[Sanibel]

Joint Typhoon Warning Graphic takes it right for the shallows of Bangladesh after peaking at 120KTS!

[HURAKAN]

[Coredesat]

NRL seems to be having technical problems as everything but 97S is gone from it.

AFWA satellite image:



I posted 06Z models in the model thread, the 12Z models should be out soon.