The month of spring is beginning on a stormy note for Northern India

 

The weather has been very dry lately after a nearly winter drought due to the absence of winter rains in the region. There were weaker & less frequent active Western Disturbances which brought some rains but some of them traversed in lower latitudes as compared to their normal track. These lower latitude systems brought active spells over West, Central, and parts of Eastern India while sparing Northern India. The winter produce in the region has not been good! Now, the pattern is expected to get wet and stormy due to the active impulse of NAO coupled with favorable dynamics for the first half of the month of March. A very active Western Disturbance is set to end the dry spell with a bang across many parts of Northern India and it will bring the season’s first rainfall in many places that have been devoid of any rainfall for the past 2-3 months.

Weather synopsis 

•Western Disturbance: A Western Disturbance (WD) as an upper-level disturbance is present over North Pakistan and adj Afghanistan region with a height of 500hpa and extending up to 200hpa and magnitude of (9/10) and a trough extending from the system to the Northern Arabian Sea at a level between 500-600hpa and the system is expected to move Eastwards between 1-5th March.

•Cyclonic Circulation: An induced Cyclonic Circulation (CC) is expected to develop A Pakistan and Adjoining SW Rajasthan on 1st March. This system will further aid in pulling the moisture and enhancing the instability over the plains of Northern Indiandueing the weather watch period 

•Moisture feed: The majority of moisture will be pulled from the Arabian Sea, The WD moisture pull will converge over the foothills of the Himalayas and some orographic lifting will be done over the Aravalli range. 

•Dryline: A dryline exists at the tail end of the system and will further strengthen over the plains. This is where the most active thunderstorms will flare up. The dryline is represented by high variation in dew points between the dew points and levels of moist & dry air. The strong winds at the dryline will kick up dust in the air which might produce dust storms also high instability and cape at few spots might spin up vorticity (water/land sprouts) and low risk of tornadoes is present. 

•High instability: There is high instability in the atmosphere due to high moisture, warmer & cool air interaction, upper-level divergence, and topographic will fuel more storm development between 1-3rd March 

Weather effects

The effects of this WD will start to pop-up by the night of 29th February itself with beginning of on/off varied intensity snowfall over the Western Himalayas, Jammu, Kashmir, Leh, Himachal Pradesh and adjoing area. The outer bands form the system will start to dominate the plains in form of high level cloud.

•1st March: Instability will rise quickly as the day progresses and the dynamics will start to settle in over majority of SW-N Plains. The local topography will flare up strong thunderstorms over Aravalli, Foothills of N Himalayas. 

-Intense thunderstorms will start to develop over the parts of SW Rajasthan, Bhilwara, Jodhpur, Jaipur, Tonk, Alwar, Churu, Loharu, and parts of Madhya Pradesh and Gujarat and these spell will manifest themself with moderate to heavy rains with isolated hailstorm and loud thunder accompanied by gusty winds up to 20-60km/h

-Isolated light rains are also expected to occur over the Western Ghats, Mumbai, and MMR region in the morning and during evening/ night hours

-Places like Delhi, NCR, Parts of Haryana, and Punjab will start to see some varied intensity thunderstorm development during late afternoon into night hours with only increasing probability as the night sets in.

-Scattered thunderstorms will be producing light-nod rains with isolated heavy spells and hailstorm with thunder, lightning and gusty winds over NW Punjab, South Haryana and Various parts of Rajasthan and MadhyaPradesh and few parts of Delhi.

•2nd March: The thunderstorms spread and frequency will increase as we get towards the morning of 2nd March. T-storms of moderate intensity capable of producing moderate to heavy rains with hailstorms and gusty winds are expected to occur along the foothills of Punjab, Haryana, Chandigarh, Mohali, Panchkula, Tri-city and parts of NE Rajasthan, Aravalli and Madhya Pradesh and W-C UttarPradesh. 

-Fresh strong thunderstorms will develop during the forenoon into late afternoon hours of 2nd March over the R-C-S Rajasthan and parts of Gujarat and Maharashtra. the sets of thunderstorms towards the evening will be severe as they will directly develop over the dryline & convergence and also there are high chances for the development of an squall line. 

-Strong thunderstorms will start to form over various parts of Gujarat, Rajasthan, Punjab, and parts of W-SW Haryana during the afternoon and they all will move eastwards with a slight SW-NE movement tilt. 

-Intense moderate to heavy rains with scattered hailstorm along with gusty winds upro 35-80km/h and intense lightning and loud thunder is likely to occur in Jodhpur, Bikaner, Jaipur, Churu, Sirsa, Bathinda, Ludhiana, Parts of SW Haryana between 10 AM-1 PM.

-The development of storm will get stronger under afternoon heat, high Cape, instability and supportive dynamics. Stray Cumlonimbus will bring isolated rains in above mentioned areas post the straight line storm.

-Severe storms with dust storms will reach Punjab, Bathinda, Gurdaspur, Hoshiarpur, Rajpura, Jalandhar, Ludhiana, Patiala, Panipat, Sonipat, Rohtak, Delhi, Gurgaon, Faridabad, Ghaziabad, and adj areas between 2-7 PM and will continue to bring spells of moderate to heavy rains with isolated-scattered hailstorm and thunder and lightning between 3-8 PM

-The spell will manifest itself with growing darkness along the Southern to Western to NW horizon followed by an approaching shelf/arcus cloud and dust storm with winds gusting up to 35-80km/h

-The spell will move further Eastwards, affecting E Rajasthan, NE Madhya Pradesh, W Uttar Pradesh, Ghaziabad, Baghpat, Karnal, Kurukshetra, Ambala, Tricity, Mohali, Panchkula, Eastern Punjab, Saharanpur and Foothills of Haryana, Punjab, and NW U.P and these places are likely to get very intense spells with good spread hailstorm.

-There are good chances of occurrence of hailstorm with hailstone size up to pea size and all the way up to golf ball size.

-Crop damage at large scale very likely

•The weather will start to settle down from 3rd March and all the spells will subside by late evening. There are chances of localized development over the plains during the afternoon hours of 3rd March 

•Highly precise Nowcasts and Hyperlocal forecasts will be issues a few hours prior to the spells and will be published on our social media handles.