Data health

Storm Mode / Tracked area

Winter: Michigan

Wall mode

1 warning total · 0 tornado warnings · 4 alerts including watches and advisories

Current alert feed · checked

Change time or forecast product

Replay uses retained source bytes. Recording begins with activation; missing history is not clear weather.

Live sources keep independent clocks.

Replay coverage and interpretation

Rolling target: 24 hours; cells: six hours. Radar: NOAA MRMS national overview, 8-minute tolerance. Satellite: original GOES GeoColor day/night picture, hourly sampling, 75-minute tolerance. No interpolation or latest-image fallback. Warning and source checks retain their own clocks. “Recorded by” is collector acquisition evidence, not exact browser publication history.

Current GLM density, velocity and specialist layers are hidden during replay. Snow uses retained footprint metadata with unverified pixel time. Forecast uses one pinned issuance/run and exact valid time.

No observed replay frame displayed.

Open the complete replay reader (works without scripting or WebGL)

Warnings in area

4 of 4 alerts
  1. Freeze WarningLagrange; Steuben; Noble; De Kalb; Whitley; Allen; Miami; Wabash; Huntington; Wells; Adams; Grant; Blackford; Jay; Northern Kosciusko; Southern Kosciusko; Williams; Fulton; Defiance; Henry; Paulding; Putnam; Van Wert; AllenNWS Northern Indiana · until warning · alerts checked
  2. Frost AdvisoryAllegan; Barry; Eaton; Ingham; Van Buren; Kalamazoo; Calhoun; JacksonNWS Grand Rapids MI · until advisory · radar-alerts checked
  3. Frost AdvisorySanilac; Lapeer; St. Clair; Livingston; Oakland; Macomb; Washtenaw; Wayne; Lenawee; MonroeNWS Detroit/Pontiac MI · until advisory · radar-alerts checked
  4. Frost AdvisoryElkhart; Starke; Pulaski; Marshall; Fulton; White; Cass; Northern La Porte; Eastern St. Joseph; Southern La Porte; Western St. Joseph; Cass; St. Joseph; Branch; Hillsdale; Northern Berrien; Southern BerrienNWS Northern Indiana · until advisory · radar-alerts checked

Watched places

Places saved on this device appear here with scripting enabled.

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Layers

Map

  • Freeze Warning 1
  • Frost Advisory 3

NWS’s polygons as issued, or the zones a zone-issued alert names; SPC’s watches by their counties. Checked . Data: NOAA/NWS, NOAA/SPC.

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 18:00:00 UTC, picture retrieved 2026-10-18 03:23:05.460 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) · current

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

    Station and river observations (61)

    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.

    Showing 61 of 61 listed sources. All surface stations and retained trends · All supported gauges and forecasts

    Inspector

    Choose a warning, cell or place

    Select a row or map feature for its official details. Overlapping features offer a choice; all peer warnings remain in the list.

    Recent source changes

    Recording coverage and limits
    • warnings: retained from 2026-10-17T04:55:48.190Z through 2026-10-18T04:55:06.202Z
    • outlooks: retained from 2026-10-17T04:55:48.190Z through 2026-10-18T04:55:07.065Z
    • hydro: retained from 2026-10-17T04:55:48.190Z through 2026-10-18T04:55:05.918Z
    • analysis: retained from 2026-10-17T04:55:48.190Z through 2026-10-18T04:45:08.397Z
    • winter: retained from 2026-10-17T04:55:48.190Z through 2026-10-18T04:53:05.076Z

    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.

    SPC preliminary storm reports

    0 matching reports · 0 in this monitoring area

    Source current · checked 2026-10-18T04:55:05.737Z. Convective day: 2026-10-17T12:00:00.000Z to 2026-10-18T12:00:00.000Z (12–12 UTC). Reports are filtered to the monitoring geography.

    All reports are preliminary. Counts are reports, not unique storms or confirmed tornadoes. Measured versus estimated values and observer identity are not separate fields in the SPC file; the original comment is preserved. Warning polygons and radar-cell detections are separate evidence.

    No readable reports match this scope and type in this cached convective-day file. Missing reports do not establish safe conditions.

    Spotlight: Winter Storm Severity Index

    1 of 7

    Winter Storm Severity Index

    WPC: “WSSI does not depict official warnings and should always be used in context with official NWS forecasts and warnings.”

    • Winter Weather Area
    • Minor Impacts
    • Moderate Impacts
    • Major Impacts
    • Extreme Impacts

    Highest in this area, by day and by cause

    Day 1
    nothing drawn
    Day 2
    nothing drawn
    Day 3
    nothing drawn
    Snow amount, Days 1–3
    nothing drawn
    Snow load, Days 1–3
    nothing drawn
    Ice, Days 1–3
    nothing drawn
    Blowing snow, Days 1–3
    nothing drawn

    Each day and cause on the Winter tab, with its own issue time

    WPC’s WSSI, overall impact, Days 1–3, valid to , issued . WPC issues each day and cause on its own clock. Not a warning, and not a chance. Data: NOAA/NWS/WPC.

    Chance of Moderate impacts or worse, Day 1

    WPC: “WSSI does not depict official warnings and should always be used in context with official NWS forecasts and warnings.”

    • 5–10%
    • 10–20%
    • 20–30%
    • 30–40%
    • 40–50%
    • 50–60%
    • 60–70%
    • 70–80%
    • 80–90%
    • 90–95%
    • 95% or more

    Each level and day on the Winter tab

    WPC’s WSSI-P: no chance drawn for Day 1. Data: NOAA/NWS/WPC.

    Chance of at least 4 inches of snow, Day 1

    WPC gives no chance of 4 inches of snow or more in this area over the next three days, so Day 1’s 4 inches is shown.

    • Slight: at least 10%
    • Moderate: at least 40%
    • High: at least 70%

    Every day and amount on the Winter tab

    WPC’s Probabilistic Winter Precipitation Forecast, to , issued . Outlines, as WPC draws them. Data: NOAA/NWS/WPC.

    Winter watches, warnings and advisories

    • Freeze Warning 1 1 not yet in effect · until · NWS Northern Indiana
    • Frost Advisory 3 3 not yet in effect · until · NWS Detroit/Pontiac MI, NWS Grand Rapids MI, NWS Northern Indiana

    NWS’s winter and cold alerts in force in the area, by event as issued, each counted once, with the offices that issued them and the latest end. Data: NOAA/NWS.

    Snow on the ground

    NOHRSC snow depth and snow water equivalent use the source’s original pictures and legends, with qualified footprint times. Open the cached source page for availability and retained history. This wall has no snow picture to rotate; missing imagery does not mean no snow.

    NOHRSC snow analysis and retained pictures

    Data: NOAA/NWS/NOHRSC. Snow analysis, not a measurement at a place.

    WPC’s heavy snow and icing discussion

    The whole discussion

    Issued , for to . WPC’s words, as written. Data: NOAA/NWS/WPC.

    Radar, winter preset

    The Radar page’s winter preset over the area: HRDPS forecast snow with NWS’s warnings on top, loaded by your browser. A forecast, labelled as one there.

    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 04:22Z.

    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
    Michigan (NWS states: MI)
    Hazards
    Winter 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 4

    1. Freeze Warning11 not yet in effect · until 13:00Z
    2. Frost Advisory33 not yet in effect · until 13:00Z
    Every alert in this area, most urgent first
    1. Freeze WarningLagrange; Steuben; Noble; De Kalb; Whitley; Allen; Miami; Wabash; Huntington; Wells; Adams; Grant; Blackford; Jay; Northern Kosciusko; Southern Kosciusko; Williams; Fulton; Defiance; Henry; Paulding; Putnam; Van Wert; AllenFrom · until · NWS Northern Indiana · drawn over this area
    2. Frost AdvisoryAllegan; Barry; Eaton; Ingham; Van Buren; Kalamazoo; Calhoun; JacksonFrom · until · NWS Grand Rapids MI
    3. Frost AdvisorySanilac; Lapeer; St. Clair; Livingston; Oakland; Macomb; Washtenaw; Wayne; Lenawee; MonroeFrom · until · NWS Detroit/Pontiac MI
    4. Frost AdvisoryElkhart; Starke; Pulaski; Marshall; Fulton; White; Cass; Northern La Porte; Eastern St. Joseph; Southern La Porte; Western St. Joseph; Cass; St. Joseph; Branch; Hillsdale; Northern Berrien; Southern BerrienFrom · until · NWS Northern Indiana

    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.