COMPREHENSIVE     FORECAST & REVIEW

[VALIDITY: 20TH OCTOBER, 2018]

 

PAST WEEK EVENTS

“A Brief Review”

  • Cyclonic Formations in Arabian Sea (ARB) & Bay of Bengal (BOB)
  • Back-To-Back Western Disturbance (WD)
  • Drop In Temperatures
  • Karachi SO^2 Concentration
  • Drought In Southern Pakistan

Cyclonic Formations in Arabian Sea (ARB) & Bay of Bengal (BOB):

1. Cyclone Luban: An anti-clockwise circulation formed off the Kerala coast on 4th October, Thursday which gradually intensified in next 24 hours into Low Pressure Area (LPA) named “Invest 99A”  that drifted WNW and then towards West converting into Deep Depression/Tropical Storm by early Sunday, 7th October 2018. The storm was severely effected by dry air mass, timings of WD, low Sea Surface Temperature (SST) and High Pressure (HP) ridge over north Arabian sea.

Cyclone Luban on 11th October

Thus Cyclone of Cat-1 “TC 5A” formed by early Monday, 8th October off the coast of Oman-Yemen in SW Arabian Sea, seemed to be stationary while moving with very low pace, in west direction, because of disrupted jets upon strong WD arrival in Upper Pakistan and low SST along Oman-Yemen coasts pausing Luban to be strengthen. However the WD withdrew and Titli made landfall in BOB by 11th October, Thursday allowing Luban to continue its track &  gaining strength. The cyclone reached peak intensity late on Thursday night, with sustained winds over 140 km/h (87 mph).

Latest Luban Satellite Image on Friday, 12th October[1]

[1] Hence Cat-1 Cyclone Luban (lying 275 km ESE of Salalah, Oman) continued its track towards Yemen-Oman Coasts in W/WSW direction firstly strengthening continuously till Friday, 12th October, moving SW/WSW then loosing strength occasionally due to ‘vertical wind shear’ & ‘cool SST’, converting into Deep Depression. However Luban when reached near the coast by mid Saturday it again strengthen into Severe Cyclonic Storm with max. 102 kmph wind speed near its center.

Luban Track 10/14

Luban made landfall as ‘Tropical Storm’ on Al-Mahra coast of northern Yemen on Sunday, 14th October with max. sustained winds 74 kmph in Sea. The most effected regions were Southern Oman’s Dhofar province and Northern Yemen, while about all the parts of Yemen enjoyed rains till next two days [Tuesday] at times. The max. gust was recorded between 54 – 84 kmph with waves reaching 6 – 8 meter high. The support from gulf of Aden caused daily severe local thunderstorms in Southern Oman between 11 – 16 October. Moreover, southern and SW parts of Hizaj (injudicious KSA) witnessed occasional rains till 19th of October.

2. Cyclone Titli: Simultaneously another UAC formed in central BOB on 8th October that moved NW intensifying into Deep Depression turning into Cat-1 Cyclone Titli “TC 6B” by 9th October, continued its motion in NW direction while gradually intensifying from Cat-1 cyclone into Cat-2 cyclone by 10th October, moved with 10 kmph in NW direction making landfall on Indian Odisha’s Gopalpur Coast on early 11th October, Thursday (around 5:30 am). The maximum wind speed was recorded 145 kmph between NE Andhra Pradesh & Odisha. Under the influence of Sub Tropical Western Jets (STWJ), the system tended to re-curve in NE direction towards West Bengal & Bangladesh by friday, 12th October. The major affectants  were India’s eastern provinces of NE Andra Pradesh, Odisha, West Bengal, and Bangladeshi States.

Cyclone Titli Makes Lanfall in Odisha 

Back-To-Back Western Disturbance (WD) Causing Drops In Temperatures:

A weak WD was already in action between 3rd October – 6th October, as caused scattered developments in upper Pakistan. The total maximum rain of that spell recorded in; Punjab was 27.2 mm in Murree, KPK was 18 mm in Kalam, GB/AJK was 22 mm in Muzaffarabad. While the major cities recorded total of; Islamabad – 8 mm, Lahore – 6 mm.

The video broadcasting tornado was being reported from Lahore. 

Another moderately Strong WD lashed upper Pakistan by late-8th October. Widespread thunderstorm was formed accompanied with severe weather events of dust storms, hailstorms, tornado, rainfalls, snowfalls and lightnings (thunders were reported to lesser extent).

Abbotabad Before Sunset on 8th October, 2018

The total maximum rain recorded in the spell in; Punjab was fluctuating between 25 mm – 37 mm in different areas of Islamabad, KPK was 34.5 mm in Kakul, Gilgit Baltistan was 47.5 mm in Astore, and Azad Jammu & Kashmir was 33 mm in Muzaffarabad.

Image may contain: mountain, sky, outdoor and nature

Lalusar Lake on 11th October, 2018

While Sindh & Balochistan remained hot & dry through out the decade. However the temperatures were lowered upon WD arrival & departure. The minimum temperature in Sindh was decreased by 1°C  – 1.5°C  while the maximum temperature was decrease by mean of 3°C – 4°C, specially after WD withdrawal by late 9th October, Tuesday.

Karachi SO^2 Concentration: 

Just after the WD withdrawal, the dual cyclones were present in seas of ARB & BOB the HP ridge was formed over northern Arabian sea while weak low level circulation (LLC) was present in West of metropolis therefore blocking the already jammed sea winds caused the citizens to suffer the medical conditions due to SO^2  concentrated pollutant slow winds blowing from the side of Fish Harbour (in SE) and Korangi Industrial Area (also SITE Area in West).  The winds, due to LLC, were not allowed to pass even most of it was circulating between late 9th October – 12th October. Over the night of 12th October, no winds were observed through out the plains of Sindh (meanwhile cyclone Luban lied in ESE of Salalah, Oman & cyclone Titli had made landfall & was pouring the region).

Drought in Southern Pakistan:

Pakistan had recorded -24.7% less rainfall departure from normal this year in peak Monsoon months of May – August; Sindh and Balochistan were measured to be -69.5% and -45.7% below rainfall than normal respectively. While KPK standed at -49.9% below than normal, hence the rainfall in Punjab & GB/AJK were +8.4% and +18.5% above than normal.

However the drought condition were balanced in upper Pakistan’s KPK and SE Balochistan. The current scenario remarks the ‘above normal rainfalls‘ in upper half of Pakistan while ‘moderate drought‘ conditions are expected to prevail in Sindh & Balochistan until the rain arrives.

Due to water level subside in Hub dam, the water pumping to western district was stopped for a while leaving people to suffer ‘moderate to severe’ water crisis. The conditions may worsen after mid-November, if no rain event occurs in vicinity.

Image may contain: ocean, sky, outdoor, text and water

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Weekly Forecast

(Valid Till 20th October, 2018)

Creative: Admin Mohammad Faizan Khan

Overview:

The moderately-strong WD has just left the country on 9th October,causing drop in temperature comprehensively through out the country. Also caused snow on elevated mountainous regions, the lowest minimum was recorded -16°C in Babusar Top, GB, Upper Pakistan.

Back to back WD are expected to lash Pakistan. A weak WD is expected to reach central Pakistan by 14th October. The HP currently lies in northern Arabian Sea in SSW of Karachi which is likely to move SE by 14th October allowing WD to dip more in South and move more in South by 16th & 19th October resulting in WD dipping into whole Pakistan’s region, while at the same moment another more-penetrating moderately Strong WD is likely to lash between 15th – 20th October, 2018; thus lowering the temperatures most by 2°C – 3°C (+/- 2°C) averagely through out the Pakistan. Hence it would be the first “Cold Wave” in the last of 2nd decade of October.

>Forecast:

  • Sindh: No significant chances of rain are in sight, however drop of   2°C – 3°C and 1.5°C – 2°C is expected in minimum and maximum temperatures respectively.  Sea breeze would resume in day times with cool dry winds in night times in coastal areas including Karachi. The night temperatures would tend to decrease more anomaly. Under the influence of WD, there are 20% – 40% chances of scattered developments in southern Sindh between 15 – 17 October while 50% chances persist between 18 – 21 October. There are upto  60% chances of scattered developments in upper, western and central Sindh, specifically region affiliated with Kirther & Suleman Ranges. Cool & Dry winds would prevail during night times, humid sea breeze would take its place in day times in coastal areas (Southern Sindh).
  • Balochistan:  There are 40% chances of isolated developments in NW & N Balochistan during 14th – 15th October, hence the chances would enhance on strong WD arrival by 16th October to 60% – 70% chances of scattered developments in northern, western, central & eastern Balochistan along Kirther ranges, specifically. The chances would persist till 19th October.
  • Punjab: The extreme norther Punjab along with northern KPK, Gilgit Baltistan and Kashmir  is likely to witness severe events through out the decades, experiencing heavy to very-heavy falls with snow on mountains. The cold wave would effect the region upmost as the threshold of WD would be max. in those regions. There are only 40% chances of developments in plains of Punjab between 12 – 15 October, however the chances would enhance upto 80% between 16 – 19 October resulting in isolated moderate falls, heavy at times through out the Punjab. Severe events like super-cell TS are moderately possible during the mentioned time.
  • KPK/FATA: Isolated moderate developments are anticipated on 14 – 15 October. Extreme northern areas would enjoy the most events. There would be maximum chances of widespread developments between 14 – 16 October causing heavy to very heavy falls with snow & hail events in majority part of province and FATA, more likely.

 

The Forecast is Prepared After Deep Parametric Observations, Hence Chances May Vary To All Extents As Changes Possible in Factors.

 

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Comprehensive Weekly Preview And Overview
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Haider Saqib

Posted by Haider Saqib

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