Tropical Storm Champi

35 kt · 40 mph · 1001 hPa · W at 10 kt

Storm Mode · JTWC Warning 5 · 15 Oct 12:00Z

Historical advisory selected · current imagery and impacts are not attached

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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.

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JTWC forecast for Tropical Storm Champi, Warning 5; rendered by MaverickWX

Published advisory track · Warning 5

Observed imagery loads separately from the advisory. The base map is not observed satellite imagery.

JTWC supplies no cone for this issuance; none is invented.

MaverickWX map · Data: JTWC · not an official graphic

Use Forecast above to pin an official issuance and valid point. The forecast table and advisory history remain available below.

Coastal observations

Scheduled public-station observations

Water levels are relative to the named datum, not flood depth above ground. Observations keep their own report times.

Coverage and interpretation

Observed water level is relative to the named vertical datum, not flood depth above ground. Observed minus predicted tide is a matched-time residual, not a universal storm-surge or inundation forecast. Buoy wind is not a cyclone maximum; significant wave height is not coastal flood depth. Missing readings are not zero.

Only operator-configured public stations are collected. Coastal context includes stations inside the named monitoring area or within 100 nautical miles of a vertex of its published outline, so offshore buoys can be included; this is a proximity rule, not an impact footprint. Cyclone-only context is within 600 nautical miles of the selected advisory center. Shown center distances are not impact radii. Station-file history without a reported position is not assigned a historical location.

NOAA CO-OPS water levels and predicted tide

Source current · checked 2026-10-18 04:38:03.992Z. 0 configured stations in this view.

No configured station has been collected in this scope. This does not establish safe coastal conditions.

NOAA NDBC wind, pressure and waves

Source current · checked 2026-10-18 04:36:03.244Z. 0 configured stations in this view.

No configured station has been collected in this scope. This does not establish safe coastal conditions.

Complete cached coastal station directory · Source health

Storm details

JTWC Warning 5 · 15 Oct 12:00Z

Center position: 11.0°N, 157.4°E
Minimum pressure: 1001 hPa
Maximum sustained wind: 35 kt · 40 mph
Movement: W at 10 kt
Change from comparison: Wind +5 kt · pressure -1 hPa
Compared with Warning 4 · 15 Oct 06:00Z

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Forecast cycle 15 Oct 12:00Z. Center position belongs to the official state’s time, not imagery time.

Watched places

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Advisory comparison

Show previous forecast as a dashed line

Solid: Warning 5 · 15 Oct 12:00Z
Dashed: Warning 4 · 15 Oct 06:00Z

Compare positions and intensity

Solid: JTWC Warning 5 · 15 Oct 12:00Z
Dashed: JTWC Warning 4 · 15 Oct 06:00Z. Comparison uses each record’s own geometry. A revision is not a landfall or impact prediction.

Current-state revision (two separate official issuances)
Field	Selected issuance	Comparison issuance	Change
Maximum sustained wind	35 kt · 40 mph	30 kt · 35 mph	+5 kt
Minimum pressure	1001 hPa	1002 hPa	-1 hPa
Center position	11.0°N, 157.4°E	10.9°N, 158.4°E	Different observation times; not a forecast shift

Forecast comparison unavailable: these records have no matching forecast valid times. No interpolation or six-hour step is assumed.

Data coverage

JTWC has no NHC cone, NHC wind probabilities or NHC civil coastal warnings. Local national services remain the warning authorities.

Geographic context: Natural Earth boundaries and representative place labels. Radar coverage is limited offshore. Satellite pixels keep their source palette and actual observation time. Missing imagery is not clear weather.

Lightning activity — GOES GLM

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

Public event region Aggregation interval Show density on map

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

Cached lightning source details and text readings

Map layers, imagery opacity and source clocks

Interactive layer controls load on this device. Published products remain available below.

Potential impacts and monitoring context

Current NWS monitoring states: GU, MP

Coastal alertsNot retained with this historical record Flooding rainOfficial rainfall context and coverage Storm surgeAvailability and coastal-only product limits Nearby severe warnings0 severe/flash-flood warnings in the named monitoring area · source current

Current warnings in the monitoring area

U.S. territories JTWC’s forecast track passes within 300 nm of, Warning 5: Guam and Northern Mariana Islands. Current geographical context; these alerts are not attributed to the cyclone and are not part of the historical advisory.

In force in this area 4

Typhoon Warning1until 16:45Z
Coastal Flood Warning1until 18:00Z
High Surf Warning1until 18:00Z
Flood Watch1until 08:00Z

Every alert in this area, most urgent first

Typhoon WarningGuam Coastal Waters; Rota Coastal Waters; Guam; Rotauntil 16:45Z · NWS Tiyan GU
Coastal Flood WarningGuam; Rotauntil 18:00Z · NWS Tiyan GU
High Surf WarningGuam; Rotauntil 18:00Z · NWS Tiyan GU
Flood WatchGuam; Rotauntil 08:00Z · NWS Tiyan GU

Most urgent first, by the Briefing’s ranking. Checked 04:38Z.

Typhoon Warning
Guam Coastal Waters; Rota Coastal Waters; Guam; Rota
Typhoon Warning issued October 18 at 12:31PM ChST by NWS Tiyan GU
Issued 17 Oct 12:39Z · ends 16:45Z
Official Typhoon Warning bulletin
Coastal Flood Warning
Guam; Rota
Coastal Flood Warning issued October 18 at 12:00PM ChST until October 19 at 4:00AM ChST by NWS Tiyan GU
Issued 17 Oct 21:55Z · ends 18:00Z
Official Coastal Flood Warning bulletin
High Surf Warning
Guam; Rota
High Surf Warning issued October 18 at 12:00PM ChST until October 19 at 4:00AM ChST by NWS Tiyan GU
Issued 17 Oct 21:55Z · ends 18:00Z
Official High Surf Warning bulletin
Flood Watch
Guam; Rota
Flood Watch issued October 18 at 4:12AM ChST until October 18 at 6:00PM ChST by NWS Tiyan GU
Issued 17 Oct 18:12Z · ends 08:00Z
Official Flood Watch bulletin

Official forecast table

Official forecast positions and intensity

JTWC Warning 5 · advisory 15 Oct 12:00Z · forecast cycle 15 Oct 12:00Z. Forecast positions are future estimates, not observed imagery. Classification is shown only where published.

Published official forecast; no interpolated positions or winds
Valid time / lead	Position	Classification	Sustained wind
16 Oct 00:00Z +12 h from forecast cycle	11.5°N, 154.9°E	tropical storm	40 kt · 46 mph
16 Oct 12:00Z +24 h from forecast cycle	11.9°N, 152.1°E	tropical storm	50 kt · 58 mph
17 Oct 00:00Z +36 h from forecast cycle	12.4°N, 149.5°E	tropical storm	60 kt · 69 mph
17 Oct 12:00Z +48 h from forecast cycle	12.9°N, 147.0°E	typhoon	75 kt · 86 mph
00:00Z +60 h from forecast cycle	13.5°N, 144.5°E	typhoon	90 kt · 104 mph
12:00Z +72 h from forecast cycle	14.0°N, 142.3°E	typhoon	105 kt · 121 mph
19 Oct 12:00Z +96 h from forecast cycle	15.7°N, 137.7°E	typhoon	125 kt · 144 mph
20 Oct 12:00Z +120 h from forecast cycle	17.7°N, 133.1°E	typhoon	125 kt · 144 mph

Advisory history and records

Retained advisory records

Return to latest advisory

Each entry selects one immutable snapshot. Intermediate, special and corrected records are separate identities where retained. Current NWS context is labelled separately. Historical impact manifests are not retained by this index; newer impacts are never attached to an earlier advisory. Same-time corrections replaced in the publisher’s index cannot be selected unless still listed.

Advisory history; retained records only
Official issuance	Revision kind	Record
JTWC Warning 15 · 00:00Z	advisory	Snapshot 8da30f44
JTWC Warning 14 · 17 Oct 18:00Z	advisory	Snapshot 066b411c
JTWC Warning 13 · 17 Oct 12:00Z	advisory	Snapshot 7b6b7d88
JTWC Warning 12 · 17 Oct 06:00Z	advisory	Snapshot adcb8e93
JTWC Warning 11 · 17 Oct 00:00Z	advisory	Snapshot 0bf22ebc
JTWC Warning 10 · 16 Oct 18:00Z	advisory	Snapshot eea89e7f
JTWC Warning 8 · 16 Oct 06:00Z	advisory	Snapshot ff92eaa6
JTWC Warning 7 · 16 Oct 00:00Z	advisory	Snapshot 9d193cf4
JTWC Warning 6 · 15 Oct 18:00Z	advisory	Snapshot 4d09f045
JTWC Warning 5 · 15 Oct 12:00Z	advisory	Snapshot 7447d924 · Selected
JTWC Warning 4 · 15 Oct 06:00Z	advisory	Snapshot 2d609133
JTWC Warning 3 · 15 Oct 00:00Z	advisory	Snapshot d96ff9c8
JTWC Warning 2 · 14 Oct 18:00Z	advisory	Snapshot d99cea2d
JTWC Warning 1 · 14 Oct 12:00Z	first	Snapshot 99aef0d4

Monitoring geography and current changes

Area: U.S. territories JTWC’s forecast track passes within 300 nm of, Warning 5: Guam and Northern Mariana Islands (NWS states: GU, MP)
JTWC issues no cone and no coastal segments, so the area is the territories its track reaches.
Hazards: Tornado, severe thunderstorm, flash flood, river flood, areal flood, coastal flood, tropical and other warnings, watches and advisories, and the forecasts for them
Window: In force now, with this warning’s forecast
Made by: JTWC’s own products, as this site’s pipeline published them, read again with each new warning. Watch another area

The storm’s area, by its warning centre’s products: everything listed is in force in this area, never “from this storm”.

Map

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

What changed, last 60 minutes

since 04:23Z, when this server began watching this area

Nothing has changed since 04:23Z.

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

All published products and source descriptions

Forecast track

The official forecast track, drawn by this site from JTWC’s Warning 5 (12:00Z). Not an official JTWC product. Data: JTWC. JTWC’s own.

Intensity forecast

The official intensity forecast, drawn by this site from JTWC’s Warning 5 (12:00Z). Not an official JTWC product. Data: JTWC. JTWC’s own.

Satellite

The storm’s page shows it on the satellite, loaded by your browser.

Open the storm’s page

Imagery from NASA GIBS: NOAA GOES and JMA Himawari.

Model guidance

The models’ tracks, which are not a forecast for Tropical Storm Champi, JTWC Warning 5

The models’ tracks, which are not a forecast, drawn by this site from JTWC’s Warning 5 (12:00Z). Not an official JTWC product. Data: JTWC. JTWC’s own.

Flash-flood risk, Day 1

Marginal
Slight

WPC’s excessive rainfall outlook, 01:00Z to 12:00Z, issued 00:35Z: a chance of flash flooding, in four categories. Data: NOAA/WPC.

River gauges in flood

No river, coastal or lake gauge in this area is in flood, observed or forecast.

NWS’s gauges at flood stage or above in the area, worst first, each with its forecast hydrograph on Rain & rivers. Data: NOAA/NWPS.

Rain expected and rain that fell

WPC’s rain forecast and MRMS’s radar estimate of the rain that fell, on the Briefing’s map for the area.

Open Rain & rivers

Data: NOAA/WPC, NOAA/NSSL MRMS.

SPC Day 1 outlook

General Thunderstorms Risk

SPC’s Day 1 categorical outlook, valid 01:00Z to 12:00Z, issued 00:54Z. SPC’s categories, as drawn. Data: NOAA/SPC.

Watches

No tornado or severe thunderstorm watch in force in this area.

SPC’s watches, by number, matched by the counties they list. Data: NOAA/SPC.

Mesoscale discussions

No mesoscale discussion reaches this area.

SPC’s mesoscale discussions whose outline reaches the area. Data: NOAA/SPC.

Storm ingredients

SPC’s hourly mesoanalysis, observed soundings and model guidance for the area, on the Analysis tab with its own clocks.

Open the Analysis tab

Drawn by the Analysis tab’s own renderer. Data: NOAA/SPC, NOAA/NCEP.

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.

Sources

JTWC warning, as published checked 04:37Z
NWS warnings and SPC watches checked 04:38Z
NWS watches and advisories checked 04:38Z
SPC mesoscale discussions checked 04:38Z
SPC Day 1 outlook checked 04:35Z
WPC excessive rainfall checked 04:35Z
NWPS river gauges checked 04:35Z
Radar live tiles, no last-good copy

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.