This map draws the contiguous United States, and Northern Mariana Islands 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.
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.
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
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.
Collector checked not reported; feed generated not reported. Zero cells does not establish coverage or clear weather. Observations from different radars are not merged.
Prepare for tropical storm
force conditions Sunday morning. Secure all vessels. Conditions
are expected to be catastrophic for small craft, and extremely
dangerous for any vessels of larger size. As Tropical Storm Champi
approaches the Marianas, stay in safe harbor.
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
Tropical Storm Warning issued October 17 at 11:12AM ChST by NWS Tiyan GU
* WHAT...Tropical storm conditions, including winds of 34 to 63
knots, are expected. Typhoon conditions, including winds of 64
knots or more are possible within the next 48 hours.
* WHERE...Tinian and Saipan Coastal Waters.
* WHEN...Onset of damaging winds beginning late tonight, continuing
into at least Sunday night, possibly longer if conditions warrant.
* IMPACTS...Destructive winds will produce dangerous seas that
could damage, capsize or sink vessels, along with drastically
reducing visibilities in heavy rain.
* ADDITIONAL DETAILS...Typhoon Champi (29W) continues to move quickly
toward the Marianas. The exact path of 29W remains subject to
change. However, guidance supports a passage through Guam coastal
waters, with damaging winds moving into Tinian and Saipan tonight
and lasting into at least Sunday night. Champi is expected to
strengthen further today as it approaches, then move through the
region as a typhoon Sunday morning. Seas will quickly rise, with
significant sea heights reaching as high as 25 feet during closest
passage of Champi. Dangerous sea conditions may continue into
Monday.
Prepare for tropical storm
force conditions Sunday morning. Secure all vessels. Conditions
are expected to be catastrophic for small craft, and extremely
dangerous for any vessels of larger size. As Tropical Storm Champi
approaches the Marianas, stay in safe harbor.
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.”
WPC’s Probabilistic Winter Precipitation Forecast, to , issued . Outlines, as WPC draws them. Data: NOAA/NWS/WPC.
Winter watches, warnings and advisories
No winter or cold watch, warning or advisory in force in this area.
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.
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.
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.
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