In its latest warning, the National Hurricane Center said Horn was a tropical storm that formed in the North Pacific Ocean on Thursday afternoon Hawaii time.
The tropical storm had sustained winds of 40 mph.
All times on the map are in Hawaii time. Note: Some forecast data is currently unavailable. From The New York Times
What does a storm look like from above?
Satellite imagery helps determine the strength, size, and organization of a storm. The stronger the storm, the more likely it is to form an eye in the center. If the eye appears symmetrical, it often means the storm isn’t encountering anything that could weaken it.
Typically, storms that move into the north-central Pacific from near North America keep their original name as determined by the World Meteorological Association, and if the storm forms in the central Pacific, it gets a traditional Hawaiian name.
Storms often approach Hawaii and affect its weather, but the islands have a relatively small land area, so named storms rarely make direct landfall. Even the smallest impacts from these storms can cause problems. In 2020, Hurricane Douglas did not hit the islands directly, but it did bring destructive winds.
During El Niño years, a large-scale weather pattern in the equatorial Pacific Ocean, warm water is pushed eastward, bringing it closer to Hawaii and creating a breeding ground for storms in the central Pacific Ocean.
El Niño also increases the number of named storms in the eastern Pacific by reducing wind shear – the variation in wind speed and direction with height – which causes storms to break up and prevent them from intensifying and developing.
This year, a La Niña (the opposite of El Niño) is likely to develop during the season, which will reduce the number of named storms in the Central Pacific.
Sources and Notes
Tracking Map Tracking data is provided by the National Hurricane Center. The map shows at least a 5 percent probability. Forecasts are up to 5 days out, up to 3 hours before the storm is reported to reach its latest location. Wind speed probability data is not available north of 60.25 degrees north latitude.
Wind Arrival Table Arrival times are generated by New York Times analysis of National Hurricane Center data. Geographic locations are from the U.S. Census Bureau and Natural Earth data. Time zones are from Google. Table shows projected arrival times for specific cities that may be reached by sustained damaging winds of 58 mph or greater. If damaging winds reach a specific location, there is less than a 10 percent chance that they will arrive before the “earliest reasonable” time and a 50 percent chance that they will arrive before the “most likely” time.
Radar Maps Radar imagery is provided by the National Oceanic and Atmospheric Administration through Iowa State University. These mosaics are produced by combining the individual radar stations that make up the NEXRAD network.
Storm Surge Map Storm surge data is provided by the National Hurricane Center. Forecasts only cover the U.S. Gulf Coast, Atlantic Coast, Puerto Rico, and the U.S. Virgin Islands. Actual areas that may be flooded may differ from those shown on this map. This map takes into account tides, but does not account for flooding caused by waves or rainfall. This map also includes intertidal areas that are regularly flooded during normal high tides.
Satellite map imagery is provided by the National Oceanic and Atmospheric Administration and the Japan Meteorological Agency through the Cooperative Institute for Atmospheric Research.
Precipitation Maps Multi-day forecast or observed precipitation totals data is provided by the National Weather Service. Single-day forecasts are provided by the National Oceanic and Atmospheric Administration.