Tropical Cyclone Phyan

[Somerset Squall]

Invest 92B has spawned the fourth tropical cyclone of the 2009 North Indian Ocean cyclone season. The storm is located in the Arabian Sea and intensity is at 35kts. Banding features continue to wrap around a healthy LLC. Conditions appear favourable for further strengthening, as shear is low and waters are very warm. 04A is forecast to push northwards, paralell to the west coast of India, along the western periphery of a steering ridge located in the western Bay of Bengal to the east of 04A. This will eventually take 04A inland north of Mumbai. At this point, 04A could be a 55-65kt storm, if the cyclone can get it's act together within the next 48hrs. Obviously therefore, northwestern India need to closely montior this new cyclone.

[Cookie]

thanks for the updates

[Cookie]

[Somerset Squall]

Some really intense convection firing over 04A at the moment, current intensity still at 35kts but expect a rise in that number if this continues:

[Cookie]

thanks for the updates

[Somerset Squall]

Intensity has increased to 40kts. Time is running out for 04A to intensify however, as shear is beginning to increase and landfall is about 36hrs away. Because of this, I will plump for somewhere between 45-55kts as being the peak intensity now. 04A is likely to bring several inches of rain north of Mumbai, which is bound to cause flooding. Unfortunately the steering pattern seems locked in so there is little chance of 04A missing land.

[Somerset Squall]

IMD have upgraded the system to Tropical Cyclone Phyan. Phyan is entering an area of higher shear, but this is being outweighed by superb outflow and very warm sea temps at the moment. However, shear is expected to increase to 40 or 50kts just prior to landfall, which will weaken the storm as it drifts onshore. Phyan will very rapidly dissipate overland as the high shear teams up with land interaction. Phyan will likely cause flooding and very high winds for a time however.

[Somerset Squall]

Phyan has intensified to 50kts, and has wobbled eastwards in response to an approaching trough to the west. This means that Phyan will probably make landfall near Mumbai rather than to the north. Phyan may intensify a little more as it stays away from the higher shear to the north. Landfall should occur in 24hrs if Phyan continues northeastwards rather than northwards.

Edited November 11, 2009 by Somerset Squall

[Cookie]

final warnings issued

JTWC Final Warning

WTIO31 PGTW 111500

MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC//

SUBJ/TROPICAL CYCLONE 04A (PHYAN) WARNING NR 008//

RMKS/

1. TROPICAL CYCLONE 04A (PHYAN) WARNING NR 008

01 ACTIVE TROPICAL CYCLONE IN NORTHIO

MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE

WIND RADII VALID OVER OPEN WATER ONLY

---

WARNING POSITION:

111200Z --- NEAR 19.2N 73.6E

MOVEMENT PAST SIX HOURS - 025 DEGREES AT 14 KTS

POSITION ACCURATE TO WITHIN 060 NM

POSITION BASED ON CENTER LOCATED BY SATELLITE

PRESENT WIND DISTRIBUTION:

MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT

WIND RADII VALID OVER OPEN WATER ONLY

DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER LAND

REPEAT POSIT: 19.2N 73.6E

---

FORECASTS:

12 HRS, VALID AT:

120000Z --- 22.0N 74.0E

MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT

WIND RADII VALID OVER OPEN WATER ONLY

DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER LAND

---

REMARKS:

111500Z POSITION NEAR 19.9N 73.7E.

TROPICAL CYCLONE (TC) 04A, LOCATED APPROXIMATELY 40 NM EAST-

NORTHEAST OF MUMBAI, INDIA, HAS TRACKED NORTH-NORTHEASTWARD AT

14 KNOTS OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE

IMAGERY AND A 111225Z AMSU IMAGE INDICATE THAT THE LOW-LEVEL

CIRCULATION CENTER HAS DECOUPLED FROM THE DEEP CONVECTION, WHICH HAS

DIMINISHED RAPIDLY UNDER STRONG VERTICAL WIND SHEAR. TC 04A PASSED

ABOUT 30NM SOUTHEAST OF MUMBAI WHICH REPORTED RELATIVELY LIGHT WINDS

RANGING FROM 10 TO 20 KNOTS WITH A MINIMUM SLP OF 993MB

(CORRESPONDING TO A 40-45 KNOT INTENSITY). CURRENT OBSERVATIONS

INDICATE RISING SLP (998MB) AND LIGHT WINDS. TC 04A IS FORECAST TO

CONTINUE TRACKING NORTHWARD TO NORTH-NORTHEASTWARD AND SHOULD

DISSIPATE WITHIN THE NEXT 12 HOURS DUE TO LAND INTERACTION AND STRONG

VERTICAL WIND SHEAR. MODEL GUIDANCE IS IN FAIR AGREEMENT WITH THE

MAJORITY OF MODELS TRACKING THE SYSTEM OVER LAND; THE UKMO IS THE

SOLE OUTLIER, TRACKING THE SYSTEM WESTWARD. THE OFFICIAL FORECAST

FAVORS THE OVER-LAND TRACK AND IS POSITIONED JUST EAST OF THE MODEL

CONSENSUS. THIS IS THE FINAL WARNING ON THIS SYSTEM BY THE JOINT

TYPHOON WARNING CENTER (NAVMARFCSTCEN). THE SYSTEM WILL BE CLOSELY

MONITORED FOR SIGNS OF REGENERATION. MAXIMUM SIGNIFICANT WAVE HEIGHT

AT 111200Z IS 15 FEET.//

NNNN

[Somerset Squall]

Indeed Cookie, Phyan made landfall a little sooner than expected, because of an acceleration towards the coast caused by the approaching trough. This trough really ramped up shear levels too, so much so that there was barely anything left of Phyan at landfall, and consequently, little damage has been reported thus far.

[Cookie]

thats always good news,

2 systems in a week that made landfall a lot faster then expected. this and Ida