About This Tool

Last updated: Sep 2025 • Version 1.0

The Weather Activity Planning Tool helps you quickly spot time windows over the next 7 days when your desired conditions are met—using hourly forecasts from the U.S. National Weather Service (NWS). It’s designed for prescribed burning and other field operations where temperature, humidity, wind, cloud cover, mixing height, transport wind, and precipitation probability matter.

ALL (every criterion met) Temperature Relative Humidity Wind Speed Wind Direction Mixing Height Transport Wind Sky Cover Probability of Precip

How to Use

1) Pick a location

Enter an address/place and click Find, or click the map to set Lat/Lon (drag marker to refine).
You can also click Use my location (browser geolocation).

Tip: The location determines your NWS forecast office and grid point.

2) Set your criteria

Temp (°F) and RH (%) ranges
Wind speed (mph) and Wind direction(s) (compass ranges)
Mixing height (ft AGL) range
Transport wind (mph) range
Max sky cover (%) and Max probability of precip (%)

3) Choose timeframe

Select Start on Day and End on Day (Day 1 = first forecast day; up to Day 7).
By default, Day 1 → Day 7.
Limiting the number of Days will result in a better display on ios devices.

4) Get the forecast

Click Get Forecast.
The top axis shows dates and 6-hour ticks; each row shows when that criterion is met.
Night hours are shaded for quick scanning.

Reading the Display

ALL row: green bars show hours where every chosen criterion is satisfied.
Each criterion has its own colored row. Bars are merged into contiguous blocks.
Night shading is computed from solar geometry at your lat/lon (local time).
Vertical lines:
- Solid lines at local midnight (day boundaries) with date labels.
- Dashed lines at 6-hour intervals (with small labels in the header).
- Dotted lines at 3-hour intervals (unlabeled).

Inputs & Formats

Field	Format	Notes
Latitude / Longitude	Decimal degrees	Accepts decimals; bounds −90..90 / −180..180.
Temperature	°F (range)	Hourly NWS temperature.
Relative Humidity	% (range)	From NWS hourly.
Wind Speed	mph (range)	Parses values like `10 mph` or `5 to 10 mph`.
Wind Direction	Compass points	Single point (e.g., `NE`) = ±11.25°. Ranges (e.g., `S-WSW`) wrap across 360° if needed. Multiple entries allowed.
Mixing Height	ft AGL (range)	From NWS grid `mixingHeight` (converted from meters to feet as needed).
Transport Wind	mph (range)	From NWS grid `transportWindSpeed` (converted to mph as needed).
Sky Cover	% (max)	Comes from NWS grid `skyCover` (forecastGridData).
Prob. of Precip	% (max)	NWS hourly `probabilityOfPrecipitation`. If missing, treated as 0.
Start/End Day	Day 1–7	Window relative to the first available hour in the NWS hourly series.

Data Sources

NWS Points API: maps lat/lon to forecast office & endpoints.
NWS Hourly Forecast: temperature, RH, wind speed/direction, PoP.
NWS Forecast Grid Data: skyCover, mixingHeight, transportWindSpeed time-slices matched to hours.
OpenStreetMap Nominatim: address/place geocoding.

All requests include a User-Agent with a contact email for responsible use.

Limitations & Notes

Forecasts are inherently uncertain and may change—always verify conditions on site.
Grid variables like mixing height and transport wind are time-sliced; alignment to hourly times uses interval matching.
Local time is used for axis labels and night shading, based on your device/browser.
Wind direction matching uses 16-point compass (22.5° steps); single points accept ±11.25°.
No data is stored server-side beyond the duration of each request.

Keyboard & Accessibility

All inputs are keyboard accessible; use Tab / Shift+Tab to move between fields.
Tooltips next to labels can be opened with keyboard focus.
Map interactions support keyboard alternatives via Lat/Lon fields.

Change Log (highlights)

Start/End Day windowing (Day 1 → Day 7)
Compass wind direction entry (NE, NNW-NE, comma-separated)
Night shading, 3-hour and 6-hour grid lines
Sky cover pulled from NWS forecast grid
NEW: Mixing Height & Transport Wind inputs and tracks
Address search & map selection with draggable marker

Questions or feedback? Click to Mail

Install Doc