north indian ocean Severe Tropical Cyclone Lehar

[Somerset Squall]

The fifth tropical tropical cyclone of the 2013 North Indian Ocean season has formed in what has been an active period for this basin. 05B is located southeast of the Andaman Islands and has winds of 30kts. Conditions are highly favourable for strengthening as the cyclone crosses the Bay of Bengal from southeast to northwest towards India on the southern side of ridging over the northern Bay Of Bengal. Shear is low, waters are very warm if not hot in places along track, and outflow is good in all directions. This implies the potential for rapid intensification, and JTWC's estimated peak of 100kts before landfall in Eastern India could end up too low. Landfall is subject to change but Eastern India is most definitely in the firing line.

[Coast]

[Vorticity0123]

TC Lehar is currently intensifying steadily while moving generally northeastward toward eastern India. Satellite imagery shows that Lehar consists of a large blob of deep convection with little associated banding features. 

 

Dvorak satellite imagery of Lehar, showing the intense blob of convection and the lack of banding features.

 

There are currently no hints of an eye feature forming. This makes chances of RI occuring quite slim.

CIMSS MIMIC imagery also shows that the cyclone has currently no well-organized inner core, with an elongation northwest-southeast.

 

]Mim

MIMIC imagery of Lehar. The loop seems to be lagging behind a little.

 

Until the inner core of Lehar becomes better established, no RI will occur.

 

Shear analysis shows that Lehar is currently affected by 20 knots of shear from the southeast. This could explain the elongation seen in MIMIC imagery. However, shear tendency from CIMSS reveals that the shear has been decreasing somewhat in the last 24 hr, and it is forecast to decrease further in the next days, giving the cyclone an opportunity to establish a well-organized inner core.

 

Current shear tendency analysis over the past 24 hrs.

 

The current intensity is assessed at 55 knots, as from JTWC. The forecasted peak intensity of 100 kt still holds. The track forecast shows the cyclone making landfall south of Visakhpatnam, which will in this situation experience the strongest winds (northeast quadrant). However, the forecasted landfall is still 4 days out, so it will take some time until the exact landfall location is known.

 

 

The forecasted track and intensity, as from JTWC.

 

The forecast track and intensity do show quite some similarities with Phailin, which became a cat.5 TC in the bay of Bengal. The main difference is that Lehar is forecast to make landfall to the south of the location Phailin made landfall.

 

The track of Phailin, a devastating cat.5 cyclone which made landfall as a cat.3 cyclone in Northeastern India this year.

 

Unfortunately, the track of 05B takes it just to the north of the area Helen hit last week. This would increase the chances of heavy flooding over that area. 

 

Concluding, it will be a cyclone worth tracking, as it could potentially be quite a disastrous cyclone.

 

Sources: 

http://tropic.ssec.wisc.edu/

http://www.nhc.noaa.gov/

http://www.usno.navy.mil/JTWC/

http://en.wikipedia.org/wiki/Cyclone_Phailin

Edited November 24, 2013 by Vorticity0123

[Somerset Squall]

05B has been named Lehar by IMD. Winds have increased to 55kts according to JTWC. Lehar has developed a central dense overcast, indicative of a mature system. Lehar should further intensify, as shear continues to lessen, and outflow remains robust.

[Somerset Squall]

Lehar is really drenching the Andaman Islands currently:

 

 

 

[Su Campu]

148 mm have fallen in the last 24 hours at Port Blair. Pressure now 999.8 hPa, wind just 14 knots.

 

http://www.ogimet.com/cgi-bin/gsynres?ind=43333〈=en&decoded=yes&ndays=2&ano=2013&mes=11&day=24&hora=21

[Su Campu]

The eye passed Port Blair earlier, with 41-knot southwesterly winds, gusting to 70 knots.

The 3 am synop is interesting, reporting tornadoes/whirlwinds (unless it's a mistake - it also reports sudden drops in relative humidity (999-groups), which looks unlikely, given the constant temp/dewpoint readings).

AAXX 25034 43333 21493 82541 10246 20246 49971 76398 8672/

333 20222 56599 59139 6213/ 84712 85617 88458 91025 91954 99957 91070 91941 99957=

The 91954 and 91941 groups mean whirlwinds of "moderate intensity to the south" and "slight intensity to the northeast", respectively. Maybe there were?

[Coast]

Tropical storm Lehar is forecast to strike India as a severe cyclonic storm at about 06:00 GMT on 28 November.

 

Tropical storm Lehar is forecast to strike India as a severe cyclonic storm at about 06:00 GMT on 28 November. Data supplied by the US Navy and Air Force Joint Typhoon Warning Center suggest that the point of landfall will be near 16.9 N, 82.8 E. Lehar is expected to bring 1-minute maximum sustained winds to the region of around 175 km/h (109 mph). Wind gusts in the area may be considerably higher.

 

According to the Saffir-Simpson damage scale the potential property damage and flooding from a storm of Lehar's strength (category 2) at landfall includes: Storm surge generally 1.8-2.4 metres (6-8 feet) above normal. Some roofing material, door, and window damage of buildings. Considerable damage to shrubbery and trees with some trees blown down. Considerable damage to mobile homes, poorly constructed signs, and piers. Coastal and low-lying escape routes flood 2-4 hours before arrival of the storm center. Small craft in unprotected anchorages break moorings. There is also the potential for flooding further inland due to heavy rain.

 

 

http://www.trust.org/item/20131124124842-w2n29/?source=hppartner

[Somerset Squall]

Lehar has continued to strengthen, and now has an intensity of 70kts. Moderate shear has prevented rapid intensification, but warm waters and good outflow have allowed a slow intensity gain. Lehar doesn't have a visible eye yet, though the convection in the slightly elongated central dense overcast remains very deep. Rapid strengthening is no longer expected.

Despite this, Lehar is still a dangerous cyclone that is set to impact eastern India as a category 2 or 3 on the Saffir-Simpson scale.

Edited November 25, 2013 by Somerset Squall

[Coast]

 

The Andaman Islands received an unwelcome visitor on November 25 in the form of Tropical Cyclone Lehar. NASA's Terra satellite captured a picture of the visitor as it was making its exit from the islands and into the Bay of Bengal.

 

Tropical Depression 05B formed off the west coast of the Malay Peninsula on November 23 and strengthened into Tropical Cyclone Lehar as it moved from the Andaman Sea over the Andaman Islands and is now working its way into the Bay of Bengal and toward India. The Andaman Islands are located in the eastern Bay of Bengal. Burma lies north and east of the island group and India lies to the west.

 

Tropical Cyclone Lehar was over the Andaman and Nicobar Islands at the time NASA's Terra satellite flew overhead and captured a visible image of the storm. On November 25, 2013 at 04:25 UTC/Nov. 24 11:25 p.m. EST, the Moderate Resolution Imaging pectroradiometer or MODIS instrument that flies aboard Terra took a picture of the tropical cyclone as the eastern side of the storm covered the island. Most of Cyclone Lehar was west of the island in the Bay of Bengal, although the northeastern edge of the storm extended over west-central Burma, bringing clouds to Yangon, capital city of the Yangon region. By November 26, Lehar was bringing rainfall and gusty winds to the region.

 

At 1500 UTC/10 a.m. EST on November 25, Tropical Cyclone Lehar had maximum sustained winds near 65 knots/74.8 mph/120.4 kph, achieving hurricane-force. It was centered near 12.6 north and 90.6 east, about 550 nautical miles/633 miles/1,019 km southeast of Visakhapatnam, India. Lehar is moving away from Burma and toward the west-northwest at 7 knots/8 mph/12.9 kph. Lehar is generating 20-foot/6.0 meter high seas Forecasters at the Joint Typhoon Warning Center expect that warm water temperatures and low wind shear will assist Lehar in intensifying as it moves in a west-northwesterly direction across the Bay of Bengal. Forecasters expect maximum sustained winds to peak near 100 knots/115.1 mph/185.2 kph before making landfall in eastern India. As a result warnings are already in effect for India. Lehar's winds area expected to affect Northern Andhra Pradesh and southern Odisha by Wednesday, November 27.

 

 

 

http://phys.org/news/2013-11-nasa-tropical-cyclone-lehar-andaman.html#jCp

[Somerset Squall]

Lehar strengthened to 75kts earlier, but has weakened back to 70kts. Despite the tremendous area of convection present, the inner core is not well organised, with no signs of an eye. Moderate shear has prevented this cyclone from strengthening further, and JTWC now forecast little intensity change prior to landfall, as good outflow battles moderate shear to provide an environment not ideal for strengthening, but supportive of a storm of Lehar's intensity.

[Coast]

'Severe' cyclone Lehar set to hit Andhra Pradesh coast soon

 

Just week after being hit by cyclone Helen, Andhra Pradesh is again preparing to face another 'very severe' cyclone, Lehar, located in the Bay of Bengal.

 

NASA’s Tropical Rainfall Measuring Mission satellite called TRMM satellite passed over Lehar and measured rainfall and cloud heights to give scientists an understanding of how the storm is behaving.  The TRMM instruments found that rain was falling at a rate greater than 64 mm per 2.5 inches per hour in Lehar’s center and in a band of intense rain wrapping around Lehar’s northwestern side. Some strong thunderstorms within Lehar were reaching heights above 15.25 km per 9.5 miles.

 

Northern Andhra Pradesh and southern Odisha are expected to feel Lehar’s effects on Wednesday, when winds are expected to reach up to 91.7 knots per 105.6 mph per 170 kph. The Joint Typhoon Warning Center (JTWC) have predicted that Lehar’s sustained wind speeds will reach 95 knots per 109 mph on Thursday and then decrease to about 85 knots per 98 mph before hitting India’s east-central coast.

 

 

http://www.dnaindia.com/india/report-severe-cyclone-lehar-set-to-hit-andhra-pradesh-coast-soon-1925618

[Somerset Squall]

Lehar has further weakened, to 65kts. The convective canopy has shrunk and the LLC has further elongated due to ever increasing shear. Further weakening is expected before landfall, so although rain is still a serious threat to eastern India, Lehar is not quite the beast it was expected to be at landfall.

[Somerset Squall]

Lehar is falling apart, fast. Winds are down to 40kts. Dry air and shear are causing the convection associated with Lehar to rapidly dissipate. There won't be much left of Lehar at landfall in the next 24 hours at this rate, which is very good news for India, but not expected.

[Coast]

 

As Lehar moves west-northwestwards towards Andhra Pradesh from the Bay of Bengal, it turned into deep depression and the wind speed has been reduced to 20 kmph. According to an IMD bulletin on Thursday morning, Lehar lay centred at about 120 km east-southeast of Machilipatnam and 160 km south of Kakinada. Experts say the reason the intensity has come down is because of cold temperature, wind shear and also cold wind from central India. The storm has lost much of its energy.

"There's no danger," head of the cyclone warning system in the weather office, M Mohapatra, said.

 

However, the weather department has said that squally winds speed reaching 50-70 kmph are likely to prevail along the coastal regions of Andhra Pradesh during next 12 hours. It also forecast rainfall at most places with isolated heavy to very heavy falls in coastal Andhra Pradesh and Yanam district of Puducherry (geographically a part of Andhra) till Friday. Rainfall at most places with isolated heavy to very heavy falls would also occur over Telangana during next 36 hours. About 35,000 people have been evacuated in the coastal districts of Andhra Pradesh where the storm was set to make landfall.

 

 

http://www.ndtv.com/article/cheat-sheet/lehar-weakens-further-cyclone-warning-for-andhra-pradesh-lifted-451837?curl=1385624544