How much of the sky cloud will cover, in percent, hour by hour. Clear sky is the map itself; the thicker the cloud, the brighter it is drawn. Played, the cloud decks drift across the country. A frame every 3 hours to 3 days, then every 6 hours to 7 days, played from now as a loop of 1 to 7 days. More on this picture, and every picture the map shows.
Every storm the radars are tracking, the strongest first: hail, rotation, how high it reaches and where it is heading. Each is on the map above: a dot, or a ring for a strong or severe storm with a line to where it will be in an hour.
416 storms tracked: 0 severe, 1 rotating, 1 likely to hail. Listed: the strongest near a town, 30 at most; every storm is on the map.
| Sarasota, FL35 miles west | 0% | Rotating, strength 7 | 25,700 ft | 55 dBZ | northwest, 14 mph |
|---|---|---|---|---|---|
| Corpus Christi, TX51 miles south | 20% | - | 32,100 ft | 53 dBZ | southwest, 12 mph |
| Brunswick, GA61 miles east | 0% | Weak spin, strength 4 | 20,700 ft | 55 dBZ | northwest, 24 mph |
| Clemson, SC21 miles north northwest | 0% | Weak spin, strength 2 | 16,000 ft | 57 dBZ | east southeast, 2 mph |
| Galveston, TX57 miles south southwest | 10% | - | 26,000 ft | 52 dBZ | west, 18 mph |
| Sarasota, FL32 miles south southwest | 10% | - | 19,300 ft | 52 dBZ | west, 16 mph |
| Galveston, TX49 miles east southeast | 0% | Weak spin, strength 1 | 29,100 ft | 51 dBZ | southwest, 16 mph |
| Galveston, TX19 miles north northeast | 0% | Weak spin, strength 2 | 15,800 ft | 53 dBZ | west southwest, 26 mph |
| Sarasota, FL18 miles west northwest | 0% | - | 18,600 ft | 54 dBZ | northwest, 14 mph |
| Miami, FL17 miles southwest | 0% | Weak spin, strength 3 | 5,500 ft | 54 dBZ | - |
| Sarasota, FL42 miles west southwest | 0% | - | 25,400 ft | 52 dBZ | north northwest, 18 mph |
| Manistique, MI27 miles east southeast | 0% | - | 13,100 ft | 55 dBZ | east northeast, 59 mph |
| Tybee Island, GA17 miles south southeast | 0% | - | 20,100 ft | 53 dBZ | northeast, 16 mph |
| Tampa, FL34 miles west southwest | 0% | - | 7,800 ft | 56 dBZ | west northwest, 12 mph |
| Galveston, TX52 miles east southeast | 0% | Weak spin, strength 1 | 22,800 ft | 51 dBZ | west, 24 mph |
| Miami, FL21 miles southwest | 0% | Weak spin, strength 3 | 6,300 ft | 53 dBZ | northwest, 24 mph |
| Brunswick, GA53 miles east southeast | 0% | - | 17,700 ft | 53 dBZ | north northwest, 14 mph |
| Sarasota, FL23 miles south southwest | 0% | - | 19,500 ft | 52 dBZ | north northwest, 18 mph |
| Corpus Christi, TX33 miles east northeast | 0% | Weak spin, strength 2 | 18,100 ft | 50 dBZ | west southwest, 24 mph |
| Galveston, TX37 miles southwest | 0% | - | 9,400 ft | 54 dBZ | west southwest, 20 mph |
| Tybee Island, GA34 miles south southeast | 0% | - | 16,800 ft | 52 dBZ | north, 22 mph |
| Edisto Island, SC71 miles southeast | 0% | - | 20,300 ft | 51 dBZ | north, 16 mph |
| Tybee Island, GA30 miles south | 0% | - | 20,100 ft | 51 dBZ | northeast, 26 mph |
| Galveston, TX5 miles north northwest | 0% | Weak spin, strength 2 | 16,000 ft | 50 dBZ | west southwest, 26 mph |
| Sarasota, FL63 miles south southwest | 0% | - | 18,500 ft | 51 dBZ | northwest, 14 mph |
| Alexandria, LA4 miles west | 0% | Weak spin, strength 2 | 14,200 ft | 50 dBZ | west, 2 mph |
| Sarasota, FL27 miles southwest | 0% | - | 16,000 ft | 51 dBZ | west northwest, 22 mph |
| Sarasota, FL40 miles southwest | 0% | - | 19,900 ft | 50 dBZ | west northwest, 20 mph |
| Myrtle Beach, SC69 miles south southeast | 0% | - | 15,100 ft | 51 dBZ | north northwest, 5 mph |
| Marquette, MI7 miles south | 0% | - | 6,200 ft | 53 dBZ | northeast, 62 mph |
The radar ranks each spin it finds inside a storm from 1 to 25: 5 and over is a rotating storm, the kind that can bring large hail and tornadoes; under 5 is a weak spin. A tornado signature is a tight spin near the ground, where a tornado may be forming or on the ground. Read the warnings in force on Alerts, and the Field Book on a Supercell, a Tornado and How to read a warning. As data: /radar/cells.json.
Seven pictures of the same storms. The radar shows where rain and snow are now; the tops, how tall the storms stand; the rate, how hard it falls; the totals, how much has come down.
Reflectivity
Latest
How strongly rain, snow and hail send the radar’s pulse back, from every radar in the national network joined into one picture. The stronger the return, the heavier the fall. Each picture is checked against the national analysis, and echo it does not confirm is left out.
A picture every 5 minutes, played as a loop of 1 to 24 hours.
Show on the mapField Book: WSR-88D radar
Echo tops
Latest
How high each storm reaches, in thousands of feet: the highest the radar still finds rain or hail. Ordinary showers stop near 20,000 ft; a top over 45,000 ft is a towering storm, the kind that brings hail and damaging wind.
A picture every 5 minutes, played as a loop of the last hour.
Show on the mapField Book: Overshooting top and above anvil plume, Cumulonimbus architecture
Falling now
Latest
How hard it is raining or snowing at this moment, in inches of water an hour. Under 0.1 inch an hour is light rain; over 0.3 is heavy; an inch an hour is a downpour that can flood streets.
A picture every 2 minutes, played as a loop of 1 to 24 hours.
Show on the mapField Book: Thunderstorm
Rain total, 1 hour
Latest
All the rain that fell in the last hour, in inches, totalled by the radar network. Snow counts as the water it melts to. The quickest way to see where a downpour is falling.
A frame each hour, played as a loop of 6 hours to 3 days.
Show on the mapField Book: Flash flood
Rain total, 24 hours
Latest
The rain of the last 24 hours, in inches. The map to read after a storm: where the heaviest totals fell, and which ground is soaked. Played, it shows the rain gathering where the storms pass.
A frame each hour, played as a loop of 6 hours to 3 days.
Show on the mapField Book: Flash flood
Rain total, 48 hours
Latest
The rain of the last 48 hours, in inches: a slow storm, or two in a row, added up. Played, each frame is the two days to its own hour, so the swaths of rain move across the country.
A frame each hour, played as a loop of 6 hours to 3 days.
Show on the mapField Book: Flash flood
Rain total, 72 hours
Latest
The rain of the last three days, in inches: a long storm whole, and the totals that lead to river flooding. Played, each frame is the three days to its own hour.
A frame each hour, played as a loop of 6 hours to 3 days.
Show on the mapField Book: Flash flood
The forecast for the lower 48, to seven days ahead: the temperature hour by hour, the day’s highs and the night’s lows, the wind and its gusts, the chance of rain, how much rain and snow will fall, the sky, and the chance of thunder. Each plays forward from now, on the same map as the radar.
Forecast, hour by hour
For
The temperature ahead across the lower 48, hour by hour to seven days. Played, it shows the day warming and the night cooling, and cold and warm air moving across the country behind the fronts.
A frame every 3 hours to 3 days, then every 6 hours to 7 days, played from now as a loop of 1 to 7 days.
Show on the mapField Book: Lapse rates and stability, Stevenson screen and siting
Forecast, each day
For
The highest temperature of each day for the next seven days, the hours from 7 AM to 7 PM Eastern Standard Time across the country. Where the heat builds, and where cold air holds.
A frame each day for 7 days, played from today.
Show on the mapField Book: Heat wave and heat dome, Radiation budget
Forecast, each night
For
The lowest temperature of each night for the next seven days, the hours from 7 PM to 7 AM Eastern Standard Time. Where frost and freezing can reach, and where the night stays warm.
A frame each night for 7 days, played from tonight.
Show on the mapField Book: Radiation budget
Forecast, hour by hour
For
The wind ahead, 33 ft above the ground, in miles an hour, with lines that flow the way it blows and as fast. Strong wind turns the map amber and red; the lines show where it comes from and where it goes.
A frame every 3 hours to 3 days, then every 6 hours to 7 days, played from now as a loop of 1 to 7 days.
Show on the mapField Book: High wind, Coriolis as geometry
Forecast, hour by hour
For
The strongest gusts ahead, in miles an hour: the brief bursts above the steady wind that bring down limbs and power lines. Gusts over 58 mph are what a severe thunderstorm or high wind warning names.
A frame every 3 hours to 3 days, then every 6 hours to 7 days, played from now as a loop of 1 to 7 days.
Show on the mapField Book: High wind
Forecast, each 12 hours
For
The chance of at least 0.01 inch of rain or melted snow in each 12 hours, day and night, for seven days. A 70% chance means rain falls at that place on seven of ten days forecast like it.
A frame every 12 hours for 7 days, played as a loop of 3 or 7 days.
Show on the mapField Book: Water vapour as a gas
Forecast amount
For
How much rain will fall in each 6 hours, in inches, with snow counted as the water it melts to. Played, the bands of rain cross the country storm by storm.
A frame every 6 hours for 7 days, played as a loop of 1 to 7 days.
Show on the mapField Book: Flash flood
Forecast total
For
All the rain forecast from now to each frame, in inches, snow as its water: the week’s rain adding up as it plays. The map to read before a flood: where the totals build highest.
A frame every 6 hours, each the total to then, played as a loop of 1 to 7 days.
Show on the mapField Book: Flash flood
Forecast amount
For
How much snow will fall in each 6 hours, in inches of snow on the ground. Played, it shows where a storm turns to snow and how the snow moves through the mountains and the plains.
A frame every 6 hours for 7 days, played as a loop of 1 to 7 days.
Show on the mapField Book: Blizzard, Snowpack strata
Forecast total
For
All the snow forecast from now to each frame, in inches: a storm’s whole snowfall, and the week’s, adding up as it plays.
A frame every 6 hours, each the total to then, played as a loop of 1 to 7 days.
Show on the mapField Book: Blizzard, Snowpack strata
Forecast, hour by hour
For
How much of the sky cloud will cover, in percent, hour by hour. Clear sky is the map itself; the thicker the cloud, the brighter it is drawn. Played, the cloud decks drift across the country.
A frame every 3 hours to 3 days, then every 6 hours to 7 days, played from now as a loop of 1 to 7 days.
Show on the mapField Book: Cloud classification
Forecast, each 12 hours
For
The chance of a thunderstorm in each 12 hours for seven days, in percent: where storms are likely to form, before any radar can see them.
A frame every 12 hours for 7 days, played as a loop of 3 or 7 days.
Show on the mapField Book: Thunderstorm, Supercell
Every radar in the national network sweeps the sky every few minutes. The sweeps are joined into one picture of the country on a grid about a third of a mile across, and from the same sweeps the rain falling now, and the rain that has fallen, are worked out. Storm Station draws each picture in its own colours, in the browser, at every zoom, so the map stays sharp as it is enlarged.
The forecast maps are drawn from the national blend of the forecast models: the models joined into one forecast and corrected against what each place has measured, on a grid 1.6 miles across, the forecast the country’s forecasters start from. Each of its main runs, four a day, is read whole, laid onto the same grid of latitude and longitude as the radar at 2.8 miles a cell, and played forward hour by hour.
The same pictures, as tiles: /radar/now.json gives the times of the latest frames, /radar/now.json?show=p24h those of a total, and /radar/now.json?show=ft those of the forecast.