Tag: Arthur 2020

May 18, 2020 – NASA Finds a Disorganized Tropical Storm Arthur Near North Carolina Coast

Infrared imagery from NASA’s Aqua satellite and radar imagery revealed that Tropical Storm Arthur remains poorly organized. Strongest storms, according to the Aqua data, appeared along and off the southeastern coast of North Carolina.

Warnings and Watches

On May 18, a Tropical Storm Warning is in effect from Surf City to Duck, North Carolina, and for the Pamlico and Albemarle Sounds.

Satellite Imagery

NASA’s Aqua satellite used infrared light to analyze the strength of storms and found the center of circulation was displaced from the bulk of them. Infrared data provides temperature information, and the strongest thunderstorms that reach high into the atmosphere have the coldest cloud top temperatures.

On May 18 at 2:35 a.m. EDT (0635 UTC), the MODIS instrument that flies aboard NASA’s Aqua satellite showed strongest storms in Tropical Storm Arthur were along the southeastern coast of North Carolina and just off-shore. Those strong storms contained cloud top temperatures were as cold as minus 63 degrees Fahrenheit (minus 52.7 Celsius). Cloud top temperatures that cold indicate strong storms with the potential to generate heavy rainfall.

MODIS imagery showed the low-level center located near the southwestern edge of a complex of ragged convective bands.

Status on May 18, 2020

At 8 a.m. EDT (1200 UTC), the National Hurricane Center (NHC) reported the center of Tropical Storm Arthur was located near latitude 34.5 north, longitude 75.9 west. Arthur was moving toward the north-northeast near 15 mph (24 kph).  A turn toward the northeast with an increase in forward speed is expected later today, followed by a turn toward the east on Tuesday.

Maximum sustained winds are near 45 mph (75 kph) with higher gusts. While some strengthening is forecast during the next 48 hours, Arthur is likely to lose its tropical characteristics on Tuesday. Tropical-storm-force winds extend outward up to 90 miles (150 km) mainly to the east of the center.

The estimated minimum central pressure reported from an Air Force Reserve Hurricane Hunter aircraft is 1001 millibars.

Rip Currents and Life-Threatening Surf Along Coastal Areas

Swells generated by Arthur are affecting portions of the southeast U.S. coast and are expected to spread northward along the U.S. mid-Atlantic coast during the next day or two. NHC cautioned, “These swells could cause life-threatening surf and rip current conditions.”

Arthur’s Forecast Path

At 5 a.m. EDT on May 18, 2020, NOAA’s National Hurricane Center noted that Arthur’s movement is going to be affected by two factors: “A baroclinic trough (elongated area of low pressure) and associated surface front approaching from the west should cause Arthur to turn northeastward during the next several hours. The forecast track shows the center passing near or just offshore of the North Carolina Outer Banks.  By Tuesday and Tuesday night, Arthur will be entering the strong mid-latitude Westerlies, which will steer cyclone eastward in a day or two.”

For updated forecasts, visit: https://www.nhc.noaa.gov

By Rob Gutro
NASA’s Goddard Space Flight Center

May 17, 2020 – NASA Sees Development of Atlantic’s First Tropical Storm

Tropical Storm Arthur formed off the east coast of Florida from a low-pressure system (90L) that developed days before in the Straits of Florida. NASA-NOAA’s Suomi NPP satellite provided forecasters with an image of the new storm.

On Saturday, forecasters at the National Hurricane Center were closely watching System 90L, an area of low pressure that was located just offshore of the southeast coast of Florida. It continued to produce shower activity and gusty winds from portions of southeast and east-central Florida eastward across the northwestern Bahamas and the adjacent Atlantic waters.

Overnight and early on May 17, that low-pressure system became better defined and organized and it became a tropical storm over the Atlantic waters east of Florida.

Visible imagery from NASA satellites help forecasters understand if a storm is organizing or weakening. The Visible Infrared Imaging Radiometer Suite (VIIRS) instrument aboard Suomi NPP provided a visible image of Arthur late on May 16 when it had been classified as Tropical Depression 1. The shape of a tropical cyclone provides forecasters with an idea of its organization and strength, and NASA-NOAA’s Suomi NPP satellite provided a visible image of Arthur and it appeared more circular in nature.

At 5 p.m. EDT (2100 UTC) on May 16, the center of Tropical Depression 1 was located near latitude 28.4 north, longitude 78.6 west, about 505 miles or 810 kilometers south-southwest of Cape Hatteras, North Carolina. By 11 p.m. EDT, Tropical Depression 1 strengthened into a tropical storm and was renamed Arthur.

On May 17, a Tropical Storm Warning was in effect from Surf City to Duck, NC and for the Pamlico and Albemarle Sounds.

NOAA’s National Hurricane Center said, at 8 a.m. EDT (1200 UTC) on May 17), the center of Tropical Storm Arthur was located near latitude 30.3 north, longitude 77.4 west. Arthur is moving toward the north-northeast near 9 mph (15 kph).  Maximum sustained winds are near 40 mph (65 kph) with higher gusts. Tropical-storm-force winds extend outward up to 80 miles (130 km) from the center. The estimated minimum central pressure is 1002 millibars.

Some strengthening is forecast during the next 48 hours. Arthur is likely to lose its tropical characteristics on Tuesday.

A turn toward the northeast with an increase in forward speed is expected during the next 24 to 48 hours. On the forecast track, Arthur will remain well offshore the east coast of Florida, Georgia, and South Carolina today, and then move near or just east of the coast of North Carolina on Monday.

Tropical cyclones/hurricanes are the most powerful weather events on Earth. NASA’s expertise in space and scientific exploration contributes to essential services provided to the American people by other federal agencies, such as hurricane weather forecasting.

For updated forecasts, visit: www.nhc.noaa.gov

By Rob Gutro 
NASA’s Goddard Space Flight Center