Data health

Storm Mode / Tracked area

Other hazards: Guam

Wall mode

3 warnings total · 0 tornado warnings · 4 alerts including watches and advisories

Current alert feed · checked

Warnings in area

4 of 4 alerts
  1. Typhoon WarningGuam Coastal Waters; Rota Coastal Waters; Guam; RotaNWS Tiyan GU · until warning · alerts checked
  2. Coastal Flood WarningGuam; Rota; Tinian; SaipanNWS Tiyan GU · until warning · alerts checked
  3. High Surf WarningGuam; Rota; Tinian; SaipanNWS Tiyan GU · until warning · alerts checked
  4. Flood WatchGuam; Rota; Tinian; SaipanNWS Tiyan GU · until watch · radar-alerts checked

Watched places

Places saved on this device appear here with scripting enabled.

Find or save a place
Layers

Map

This map draws the contiguous United States, and Guam is beyond it. What is in force there is listed under “In force in this area”.

Agency warning geometry · no observed imagery displayed
North ↑

Interactive imagery loads separately. Missing radar does not remove warnings or imply clear weather.

Alert outlines: NOAA/NWS; cell points/observed segments: IEM/NEXRAD. A warning polygon is not a tornado footprint.

Lightning activity — GOES GLM

Total lightning, including in-cloud activity. Not ground-strike locations or a safe-to-go-outside signal.

Cached lightning observations have not loaded. An empty map is not zero lightning.

Cached lightning source details and text readings

Snow analysis — NOHRSC

Source-rendered snow depth and snow water equivalent for the lower 48. History changes this snow picture only; warnings and radar keep their own clocks.

Stored snow depth · footprint valid 2026-10-17 00:00:00 UTC, picture retrieved 2026-10-17 06:08:57.387 UTC.

No NOHRSC picture displayed on the interactive map.

  • 0 - 0.39 in
  • 0.39 - 2.0 in
  • 2.0 - 3.9 in
  • 3.9 - 9.8 in
  • 9.8 - 20 in
  • 20 - 39 in
  • 39 - 59 in
  • 59 - 98 in
  • 98 - 197 in
  • 197 - 295 in
  • 295 - 394 in
  • 394 - 787 in
NOHRSC snow analysis for the lower 48; see the adjacent source legend and time qualification
NOAA/NWS/NOHRSC’s original picture and legend. No station or address value is inferred.

NOHRSC footprint times are metadata; pixel analysis time is not independently verified. Snow-depth pixels have previously differed from the footprint time. This is modeled/assimilated snow analysis, not a measurement at a place. Unshaded and no-data areas do not establish zero snow.

Snow pictures, retained history and source provenance

Radar-derived cells (0) · unavailable

Collector checked not reported; feed generated not reported. Zero cells does not establish coverage or clear weather. Observations from different radars are not merged.

    Station and river observations (0)

    Surface source current; observed water-level source current. Each reading keeps its own time. Map markers show at most 500 stations and 500 gauges; the complete source directory is paginated.

    Circle: surface station; square: water-level gauge. Filled: current reading and source; hollow: stale, unconfirmed or missing observation. Marker color is not a hazard category. Enable “Stations and gauges” in Layers to inspect them on the map.

    • No readable station in this monitoring area. Missing does not mean calm or low water.

    Showing 0 of 0 listed sources. All surface stations and retained trends · All supported gauges and forecasts

    Selected details

    Close

    Current NWS warning

    Guam; Rota; Tinian; Saipan

    High Surf Warning

    Issued
    Updated
    Ends as issued
    Office
    NWS Tiyan GU
    Everyone should remain out of the water due to life-threatening surf conditions. Stay well away from the coast.

    Official NWS warning ↗

    The polygon is a warned area, not a tornado footprint. NWS detection tags are independent of radar algorithms and reports.

    Relevant watched places

    Save named places to check their point against every supported warning.
    Full official message

    High Surf Warning issued October 17 at 4:31PM ChST until October 19 at 4:00AM ChST by NWS Tiyan GU

    * WHAT...For the Coastal Flood Warning, significant coastal flooding
expected. For the High Surf Warning, dangerously large breaking
waves up to 35 feet for Guam, 20 to 25 feet for Rota, and 15 to 20
feet for Tinian and Saipan.

* WHERE...Guam, Rota, Tinian and Saipan.

* WHEN...From 5 PM this afternoon to 4 AM ChST Monday.

* IMPACTS...Numerous roads may be closed. Low-lying property
including homes, businesses, and some critical infrastructure will
be inundated. Shoreline erosion will occur. Breaking waves can
sweep people off their feet, and into dangerous seas. Life-
threatening swimming conditions and significant beach erosion can
be expected. Coastal inundation of 5 to 7 feet for Guam, 2 to 4
feet for Rota and 1 to 3 feet for Tinian and Saipan is possible
along with coastal flooding and beach erosion.

* ADDITIONAL DETAILS...Surf is expected to rise rapidly to dangerous
levels tonight. Coastal impacts to the western coasts of Guam and
Rota are highly dependent on the final track of Champi; passage
south of Guam would be reduced impacts whereas passage over Guam
would result in larger coastal inundation.
    Everyone should remain out of the water due to life-threatening
surf conditions. Stay well away from the coast.
    Warning-message history (4)

    Data: NOAA/NWS · PGUM.SU.W.0009

    Recent source changes

    Recording coverage and limits
    • warnings: retained from 2026-10-16T06:40:50.591Z through 2026-10-17T06:40:05.115Z
    • outlooks: retained from 2026-10-16T06:40:50.591Z through 2026-10-17T06:40:06.350Z
    • hydro: retained from 2026-10-16T06:40:50.591Z through 2026-10-17T06:35:04.889Z
    • analysis: retained from 2026-10-16T06:40:50.591Z through 2026-10-17T06:30:05.861Z
    • winter: retained from 2026-10-16T06:40:50.591Z through 2026-10-17T06:38:03.621Z

    Source-message history is not recorded imagery replay. Recorded radar/satellite imagery is not available in this view.

    Auto-updating checks this site’s cache every minute; each source keeps its own clock.

    Spotlight: Radar

    1 of 1

    Radar

    NOAA’s radar for the area, loaded by your browser as on the Radar page.

    Open the radar

    Live tiles; the radar keeps no last-good copy.

    What changed, last 60 minutes

    since , when this server began watching this area

    Nothing has changed since 06:38Z.

    The products’ own words and times, and what is no longer in force since the last read. Never written by AI.

    Monitoring area, legacy alert summary and selection rules
    Area
    Guam (NWS states: GU)
    Hazards
    Other warnings, watches and advisories, and the forecasts for them
    Window
    In force now, with the next days of SPC’s and WPC’s products
    Made by
    This address: anyone can make one, and nothing is stored. Change the area or hazards

    An area you chose, not a storm’s footprint: everything here is in force in this area, never “from this storm”.

    In force in this area 1

    1. High Surf Warning11 not yet in effect · until 18 Oct 18:00Z
    Every alert in this area, most urgent first
    1. High Surf WarningGuam; Rota; Tinian; SaipanFrom · until · NWS Tiyan GU

    Most urgent first, by the Briefing’s ranking. Checked .

    Sources

    Choose another storm or areaChange monitoring areaSource status

    Not an official warning service. Warnings and watches are the National Weather Service’s, outlooks and reports the Storm Prediction Center’s and the Weather Prediction Center’s (Data: NOAA/NWS, NOAA/SPC, NOAA/WPC). When a warning is issued for you, act on it, and use weather.gov or a NOAA Weather Radio for where you are.