PRISM & Terrain Data Planner

CPA Weather Lab · Tools · plan climate and elevation downloads for any area

AOI ready

Grid engine idle

1Location and center point

ADDRESS OR “LAT, LON”

LATITUDE

LONGITUDE

Click the map or drag the marker to move the center. Address search uses OpenStreetMap Nominatim. The marker is the geometric center or centroid of every generated shape.

2Area geometry

SHAPE

UNITS

RADIUS

EAST–WEST LENGTH

NORTH–SOUTH LENGTH

EQUAL LEG LENGTH

A true right-isosceles triangle. The chosen point is the triangle centroid, not a random vertex wandering off into a neighboring county.

NUMBER OF SIDES

EACH SIDE LENGTH

ROTATION / BEARING (DEGREES CLOCKWISE)

3PRISM grid and safe delivery

PRIMARY GRID FOR OUTPUTS

BOUNDARY RULE FOR GENERATED OUTPUT

Map grid overlayDraw selected cells when count is reasonableCell centersShow points instead of all outlines

PRISM 4 km

Touched—

Fully inside—

Edge-only—

PRISM 800 m

Touched—

Fully inside—

Edge-only—

REQUESTED PRISM OUTPUT

SAFE DELIVERY STRATEGY

POINT UNITS

BROWSER AUTOMATION

Interpolate point valuesUse PRISM inverse-distance interpolation instead of containing-cell values Unlock cloud-only source stagingRequired only when you deliberately select Cloud staging. National source grids must remain off the home connection and are deleted after clipping.

Point packageCSV, GeoJSON, Parquet and 500-location upload chunksElevation enrichmentSample the selected local 3DEP DEM

500-point filesOne PRISM upload CSV per batch0

Browser submissionsPoint batches × allowed time windows0

Earth Engine tasksServer-side point/raster exports0

Cloud-stage source filesNever transferred through the home connection0

LIVE DELIVERY ROUTING

Select products below

Routing will appear here.

LOCAL FULL-CONUS PRISM DOWNLOADS ARE DISABLED.
Auto-route never falls back to national-raster downloads. Raw national grids are available only after explicitly selecting and unlocking the guarded cloud-only route; otherwise unsupported raster requests are blocked.

4PRISM products and variables

BEGIN DATE

ENDING DATE

PRISM day: daily values represent the 24 hours ending at 12 UTC, not a local midnight calendar day.

5Terrain and derivatives

USGS 3DEP SOURCE RESOLUTIONS

1 meter DEMHighest detail; coverage varies 1/9 arc-sec · ~3 mLegacy, not nationally current 1/3 arc-sec · ~10 mNational seamless workhorse 1 arc-sec · ~30 mFast regional context

DERIVED PRODUCTS

Terrain sizes are planning estimates until the generated script queries actual 3DEP coverage and product metadata. One-meter tiles, naturally, can fill a hard drive quickly.

6Generate safe workflow bundle

BUNDLE / PROJECT NAME

RASTER OUTPUT

EARTH ENGINE CLOUD PROJECT

GOOGLE DRIVE EXPORT FOLDER

Three separate paths are generated:
1. PRISM Data Explorer Playwright jobs for 500-point batches.
2. Earth Engine scripts that clip or sample before export.
3. An optional cloud-only exact-raster fallback generated only after deliberate unlock; it still refuses to run without a second safety phrase.

Ready. Home raw-download exposure: zero.

AOI area

—

circle

Selected cells

—

800 m · touched

Browser jobs

0

500-point × time-window submissions

Home raw traffic

0 B

hard-locked at zero

Expected exports

0 B

point tables and clipped AOI rasters

Terrain output

0 B

selected DEMs and derivatives

Safe delivery and workload breakdown

no local national-raster path exists

Product	Variables	Periods	Assigned route	Browser jobs	Cloud tasks/files	Home raw transfer
Choose products and variables to populate the plan.

Browser jobs0

Home raw transfer0 B

Expected exports0 B

Point tables0 B

Generated bundle contents and run command

point-first · cloud-clipped · safety-gated

The ZIP contains:
manifest.json, AOI GeoJSON, complete point tables, 500-point upload files, a resumable Playwright PRISM browser runner, a Google Earth Engine export runner, an explicitly guarded cloud-stage raster clipper when needed, terrain tools, requirements, and precise commands. It does not contain the old local full-CONUS downloader.

unzip prism_terrain_aoi.zip cd prism_terrain_aoi bash prepare_environment.sh

Scientific and operational notes

because metadata eventually files a complaint

PRISM grid counts: the browser calculates both cells touched by the AOI and cells whose complete footprints fall inside it. Supported shapes are convex, so the full-cell test is exact for the generated geometry. Very large AOIs may switch to an explicitly marked estimate to keep a phone from becoming a hand warmer.

Safe transfer accounting: home raw-raster traffic is always zero. PRISM Data Explorer returns only requested point time series. Earth Engine clips and samples before export. Exact raster products unavailable in Earth Engine can be staged in a cloud runtime, where national source grids are deleted after AOI clipping and never traverse the home connection.

Current service basis: the PRISM bulk Data Explorer accepts no more than 500 locations per request, limits daily requests to 12 months and monthly requests to 15 years, and permits multiple variables in one request. Earth Engine currently carries official PRISM 4 km daily/monthly collections and the 928 m 1991–2020 monthly normals collection. Other 800 m time-series rasters require point extraction or guarded cloud staging.