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Atmospheric Observation

Pressure Observation Trend

Plot time-stamped pressure observations and calculate an endpoint change rate.

Use this tool

Preparing interactive controls…

Paste CSV or open a local file. Nothing is uploaded or stored. Limit: 1 MB and 1,000 data rows. Changes recalculate the report; keep a copy of your original data.

Use one pressure convention, station and unit throughout. The endpoint rate uses actual elapsed hours, not row count; this is not a forecast.

Analysis result

Samples
3
Elapsed hours
3
Pressure change (hPa)
-3
Endpoint mean rate (hPa/hour)
-1
Minimum (hPa)
1,009
Maximum (hPa)
1,012
0, 1,0121, 1,0113, 1,009031,0121,009Pressure (hPa)Hours since first sample
Lines join supplied points for readability; they do not establish continuous observations, including within gaps.
Input or flagged rows (all 3)
Time UTCPressure (hPa)
2026-06-21T09:00Z1012
2026-06-21T10:00Z1011
2026-06-21T12:00Z1009
Introduction & principle

Change=P_last−P_first; endpoint rate=change/elapsed hours. Timestamps must be valid UTC and strictly increasing. Pressure range 300–1100 hPa is an input screen, not a quality certification. No forecast is inferred.

Worked example

1012 hPa at 09:00Z and 1009 hPa at 12:00Z give −3 hPa over 3 hours, or −1 hPa/hour, regardless of intermediate sample spacing.

Detailed usage guide
  1. 1Paste or open CSV with time_utc,pressure_hpa and at least two rows.
  2. 2Keep station pressure or sea-level pressure consistent; use one location and valid UTC timestamps.
  3. 3Read the chart, range and endpoint rate. The table preserves sample times and values.
Common problems & FAQ

Can this predict a storm?

No. It summarizes supplied pressure observations only. Location, pressure-reduction convention, instrument changes and other weather evidence matter; a falling line is not a storm prediction.

Methods & references

Method reviewed November 4, 2026. These tools support learning and recording, not safety-critical decisions.

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Station Pressure Estimator

Estimate station pressure from sea-level pressure and altitude using a standard troposphere.

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Observation CSV Quality Check

Inspect a local observation CSV for missing values, duplicate or unordered UTC times and range flags.

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