Satellite
The storm’s page shows it on the satellite, loaded by your browser.
Imagery from NASA GIBS: NOAA GOES and JMA Himawari.
Tropical Storm Choi-Wan
Current advisory context · 40 kt · 46 mph · 997 hPa · W at 11 kt
Storm Mode · JTWC Warning 6 ·
Historical advisory selected · current imagery and impacts are not attached
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)No forecast-track graphic is retained for this issuance. The advisory and semantic forecast table remain available below.
Published advisory track · Warning 6
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.
Retained advisory records
Return to latest advisoryEach 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 comparison details
Solid: JTWC Warning 6 ·
Dashed: JTWC Warning 5 · . Comparison uses each record’s own geometry. A revision is not a landfall or impact prediction.
| Field | Selected issuance | Comparison issuance | Change |
|---|---|---|---|
| Maximum sustained wind | 40 kt · 46 mph | 40 kt · 46 mph | 0 kt |
| Minimum pressure | 997 hPa | 997 hPa | 0 hPa |
| Center position | 16.9°N, 146.8°E | 16.7°N, 147.9°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.
Potential impacts and monitoring context
Current NWS monitoring states: GU, MPCurrent warnings in the monitoring area
U.S. territories JTWC’s forecast track passes within 300 nm of, Warning 6: 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 7
- Flash Flood Warning11 new · until 21:30Z
- Typhoon Warning1until 18 Oct 02:45Z
- Tropical Storm Warning1until 18 Oct 02:45Z
- Coastal Flood Warning1until 18 Oct 18:00Z
- High Surf Warning1until 18 Oct 18:00Z
- Typhoon Watch1until 18 Oct 02:45Z
- Flood Watch1until 18 Oct 08:00Z
Every alert in this area, most urgent first
- Flash Flood WarningGuam County, GUuntil · NWS Tiyan GU
- Typhoon WarningGuam; Rota; Guam Coastal Waters; Rota Coastal Watersuntil · NWS Tiyan GU
- Tropical Storm WarningTinian; Saipan; Tinian Coastal Waters; Saipan Coastal Watersuntil · NWS Tiyan GU
- Coastal Flood WarningGuam; Rota; Tinian; Saipanuntil · NWS Tiyan GU
- High Surf WarningGuam; Rota; Tinian; Saipanuntil · NWS Tiyan GU
- Typhoon WatchTinian; Saipanuntil · NWS Tiyan GU
- Flood WatchGuam; Rotauntil · NWS Tiyan GU
Most urgent first, by the Briefing’s ranking. Checked .
Flash Flood Warning
Guam County, GU
Flash Flood Warning issued October 18 at 5:29AM ChST until October 18 at 7:30AM ChST by NWS Tiyan GU
Issued · ends
Official Flash Flood Warning bulletinTyphoon Warning
Guam; Rota; Guam Coastal Waters; Rota Coastal Waters
Typhoon Warning issued October 18 at 4:40AM ChST by NWS Tiyan GU
Issued · ends
Official Typhoon Warning bulletinTropical Storm Warning
Tinian; Saipan; Tinian Coastal Waters; Saipan Coastal Waters
Tropical Storm Warning issued October 18 at 4:40AM ChST by NWS Tiyan GU
Issued · ends
Official Tropical Storm Warning bulletinCoastal Flood Warning
Guam; Rota; Tinian; Saipan
Coastal Flood Warning issued October 17 at 4:31PM ChST until October 19 at 4:00AM ChST by NWS Tiyan GU
Issued · ends
Official Coastal Flood Warning bulletinHigh Surf Warning
Guam; Rota; Tinian; Saipan
High Surf Warning issued October 17 at 4:31PM ChST until October 19 at 4:00AM ChST by NWS Tiyan GU
Issued · ends
Official High Surf Warning bulletinTyphoon Watch
Tinian; Saipan
Typhoon Watch issued October 18 at 4:40AM ChST by NWS Tiyan GU
Issued · ends
Official Typhoon Watch bulletinFlood Watch
Guam; Rota
Flood Watch issued October 18 at 4:12AM ChST until October 18 at 6:00PM ChST by NWS Tiyan GU
Issued · ends
Official Flood Watch bulletin
Official forecast table
Official forecast positions and intensity
JTWC Warning 6 · advisory · forecast cycle . Forecast positions are future estimates, not observed imagery. Classification is shown only where published.
| Valid time / lead | Position | Classification | Sustained wind |
|---|---|---|---|
+12 h from forecast cycle | 17.1°N, 145.4°E | tropical storm | 45 kt · 52 mph |
+24 h from forecast cycle | 17.6°N, 144.7°E | tropical storm | 55 kt · 63 mph |
+36 h from forecast cycle | 18.6°N, 144.7°E | typhoon | 70 kt · 81 mph |
+48 h from forecast cycle | 19.9°N, 145.2°E | typhoon | 80 kt · 92 mph |
+60 h from forecast cycle | 21.1°N, 145.8°E | typhoon | 95 kt · 109 mph |
+72 h from forecast cycle | 22.6°N, 146.1°E | typhoon | 105 kt · 121 mph |
+96 h from forecast cycle | 26.2°N, 145.3°E | typhoon | 100 kt · 115 mph |
+120 h from forecast cycle | 31.8°N, 145.9°E | typhoon | 85 kt · 98 mph |
Monitoring geography and current changes
- Area
- U.S. territories JTWC’s forecast track passes within 300 nm of, Warning 6: 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 , when this server began watching this area- Extreme Wind Warning no longer in force: Guam County, GU
- Flash Flood Warning extended in time by NWS Tiyan GU: Guam County, GU
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
Flash-flood risk, Day 1
- Marginal
- Slight
WPC’s excessive rainfall outlook, to , issued : 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.
Data: NOAA/WPC, NOAA/NSSL MRMS.
SPC Day 1 outlook
- General Thunderstorms Risk
SPC’s Day 1 categorical outlook, valid to , issued . 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.
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.
Live tiles; the radar keeps no last-good copy.
Sources
JTWC warning, as published checked
NWS warnings and SPC watches checked
NWS watches and advisories checked
SPC mesoscale discussions checked
SPC Day 1 outlook checked
WPC excessive rainfall checked
NWPS river gauges checked
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.