Low-pressure system (LPS) tracks in ERA5 over South Asia (1979-2025) v4.1

Low-Pressure System (LPS) tracks over South Asia — v4.1 Region: South Asia (India, Sri Lanka, Pakistan; tracks may extend beyond these borders)Data source: 3-hourly ERA5 reanalysisMethod: Automated LoG tracking following Hunt & Fletcher (2018, doi:10.1007/s00382-019-04744-x) and Hunt et al. (2016, doi:10.1175/MWR-D-15-0138.1) Coverage Temporal span: 1940-01-01 to 2025-08-31 (inclusive) Frame epoch: frame is hours since 1940-01-01 00:00 UTC Timestep: hourly detections Variables (columns) x — longitude (deg E) y — latitude (deg N) frame — hours since 1940-01-01 00:00 UTC (int) year, month, day, hour — UTC components of detection time max_vort — maximum relative vorticity within ~4° (~400–450 km) of the LPS centre from the 850–700 hPa mean; units 10⁻⁵ s⁻¹ mean_vort_850, mean_vort_700, mean_vort_500 — mean relative vorticity within ~4° at each level; units 10⁻⁵ s⁻¹ precip_1hr — mean precipitation rate within ~8° (~800–900 km) over the hour; mm h⁻¹ precip_24hr — mean of the calendar-day 24-h precipitation sum within ~8°; mm day⁻¹ mean_wind, max_wind — 10 m wind speed within ~4° (area-mean and maximum); m s⁻¹ min_mslp — minimum mean sea-level pressure within ~4°; hPa mslp_contours — count of closed 2 hPa isobars that enclose the LPS centre (dimensionless) over_land — 1 if the centre is over land (Natural Earth 1:50 m), else 0 category — intensity class (IMD-style): 1=L, 2=D, 3=DD, 4=CS, 5=SCS, 6=VSCS, 7=SuCS track_id — unique integer identifier for each track (all points with the same track_id belong to the same system) Intensity category (category) IMD-style classes, derived from the number of enclosing closed isobars and 10 m wind (over ocean) / combination with isobars (over land).Mapping used in figures/legends: 1 = L (Low) 2 = D (Depression) 3 = DD (Deep Depression) 4 = CS (Cyclonic Storm) 5 = SCS (Severe Cyclonic Storm) 6 = VSCS (Very Severe Cyclonic Storm) 7 = SuCS (Super Cyclonic Storm) Notes: Over ocean, thresholds follow IMD (knots converted to m s⁻¹): 17, 28, 34, 48, 64, 119 kt breakpoints. Over land, the number of enclosing closed isobars (2 hPa spacing) informs classification together with wind.