Hurricane Katrina — intensity timeline (2005)¶

Pull the North Atlantic best track around late August 2005, isolate Hurricane Katrina, and chart its wind and pressure over time. Point-mode query against the HURDAT2 reanalysis via the tropycal backend. See Usage.

Setup¶

Consolidate the imports up front. earthlens provides the unified EarthLens entry point; matplotlib draws the intensity timeline. We also prepare an output directory for the best-track features.

In [ ]:

from pathlib import Path

import matplotlib.pyplot as plt

from earthlens import EarthLens

OUT_DIR = Path('tropycal_output')
OUT_DIR.mkdir(exist_ok=True)

from pathlib import Path import matplotlib.pyplot as plt from earthlens import EarthLens OUT_DIR = Path('tropycal_output') OUT_DIR.mkdir(exist_ok=True)

1 · Best-track query¶

tropycal is a vector backend, so we build the request first — source, basin (variables), date window, and a bounding box over the Gulf of Mexico and western Atlantic. Keeping the construction on its own line makes the request easy to read and re-run.

In [ ]:

track = EarthLens(
    variables=['north_atlantic'],
    data_source='tropycal',
    start='2005-08-23',
    end='2005-08-31',
    aoi=[-95.0, 15.0, -60.0, 35.0],
    source='hurdat',
    path=str(OUT_DIR),
)

track = EarthLens( variables=['north_atlantic'], data_source='tropycal', start='2005-08-23', end='2005-08-31', aoi=[-95.0, 15.0, -60.0, 35.0], source='hurdat', path=str(OUT_DIR), )

Download the fixes¶

download() fetches the best-track fixes in the window. The call is wrapped in a try/except so the notebook stays safe under nbval-lax when run offline or without the [tropycal] extra.

In [ ]:

fixes = None
try:
    fixes = track.download(progress_bar=False)
    print(len(fixes), 'fixes in window')
except Exception as exc:
    print(f'skipped live query: {type(exc).__name__}: {exc}')

fixes = None try: fixes = track.download(progress_bar=False) print(len(fixes), 'fixes in window') except Exception as exc: print(f'skipped live query: {type(exc).__name__}: {exc}')

2 · Isolate Hurricane Katrina¶

Filter the fixes to the KATRINA track, sort them in time, and report the peak intensity (the strongest wind fix and its pressure/category).

In [ ]:

if fixes is not None and len(fixes):
    katrina = fixes[fixes['name'] == 'KATRINA'].sort_values('time')
    peak = katrina.loc[katrina['vmax_kt'].idxmax()]
    print(
        f"Katrina: {len(katrina)} fixes, peak {peak['vmax_kt']:.0f} kt / "
        f"{peak['mslp_hpa']:.0f} hPa (cat {int(peak['category'])})"
    )

if fixes is not None and len(fixes): katrina = fixes[fixes['name'] == 'KATRINA'].sort_values('time') peak = katrina.loc[katrina['vmax_kt'].idxmax()] print( f"Katrina: {len(katrina)} fixes, peak {peak['vmax_kt']:.0f} kt / " f"{peak['mslp_hpa']:.0f} hPa (cat {int(peak['category'])})" )

3 · Intensity timeline¶

Chart maximum sustained wind and minimum sea-level pressure over time on a shared time axis (twin y-axes), so the classic wind-up / pressure-down signature of an intensifying hurricane is visible at a glance.

In [ ]:

if fixes is not None and len(fixes):
    katrina = fixes[fixes['name'] == 'KATRINA'].sort_values('time')
    fig, ax1 = plt.subplots(figsize=(9, 5))
    ax1.plot(katrina['time'], katrina['vmax_kt'], 'o-', color='crimson')
    ax1.set_ylabel('Max sustained wind (kt)', color='crimson')
    ax2 = ax1.twinx()
    ax2.plot(katrina['time'], katrina['mslp_hpa'], 's--', color='navy')
    ax2.set_ylabel('Min sea-level pressure (hPa)', color='navy')
    ax1.set_title('Hurricane Katrina (2005) intensity timeline')
    ax1.set_xlabel('Time (UTC)')
    fig.autofmt_xdate()
    plt.tight_layout()
    plt.show()

if fixes is not None and len(fixes): katrina = fixes[fixes['name'] == 'KATRINA'].sort_values('time') fig, ax1 = plt.subplots(figsize=(9, 5)) ax1.plot(katrina['time'], katrina['vmax_kt'], 'o-', color='crimson') ax1.set_ylabel('Max sustained wind (kt)', color='crimson') ax2 = ax1.twinx() ax2.plot(katrina['time'], katrina['mslp_hpa'], 's--', color='navy') ax2.set_ylabel('Min sea-level pressure (hPa)', color='navy') ax1.set_title('Hurricane Katrina (2005) intensity timeline') ax1.set_xlabel('Time (UTC)') fig.autofmt_xdate() plt.tight_layout() plt.show()