{{Infobox Hurricane

| Name = Tropical Storm Arthur

| Type = Tropical storm

| Year = 2020

| Basin = Atl

| Image location = Arthur 2020-05-18 1605Z.jpg

| Image name = Arthur off the east coast of North Carolina near peak intensity on May 18

| Formed = May 16, 2020

| Dissipated = May 20, 2020

| Extratropical = May 19

| 1-min winds = 50

| Damages = Unknown

| Pressure = 991

| Fatalities = None

| Areas = [[Cuba]], [[South Florida]], [[The Bahamas]], [[North Carolina]]

| Hurricane season = [[2020 Atlantic hurricane season]]

}}

'''Tropical Storm Arthur''' was a relatively strong [[List of off-season Atlantic hurricanes|off-season tropical storm]] that impacted the U.S state of [[North Carolina]] in May 2020. The first depression and first named storm of the [[2020 Atlantic hurricane season]], Arthur marked the record sixth consecutive year in the Atlantic basin with an early start before June. Originating from a broad trough that formed on May 14 near [[Cuba]], the early system slowly drifted south of Florida through the [[Florida Strait]] for 2 days, before becoming a depression on May 16 north of [[The Bahamas]], starting the Atlantic season. A day later, the system would be named Arthur and slowly drift north towards the [[Outer Banks]] of North Carolina, before skirting the same area and weakening as it moved towards [[Bermuda]].

In its formative stages, Arthur delivered heavy rainfall to the [[Florida Keys]] and [[South Florida]], and also caused rough surf off the majority off the east coast of Florida. The system's outer bands would also begin to cause significant rainfall and gusty winds off the [[Outer Banks]] of North Carolina, as well as rip currents along the majority of the Southeastern Coast.

== Meteorological history ==

[[File:Arthur 2020 track.png|left|thumb|Map plotting the track and the intensity of the storm, according to the [[Saffir–Simpson scale]]]]

On May 12, the National Hurricane Center issued a Special Tropical Weather Outlook (STWO) to discuss the possibility of [[subtropical cyclone|subtropical]] development north of the Bahamas in the proceeding days related to a broad low pressure system that was expected to form near [[Cuba]].<ref>{{cite web |title=Special Tropical Weather Outlook 1005 AM EDT Tue May 12 2020 |url=https://www.nhc.noaa.gov/archive/xgtwo/gtwo_archive.php?current_issuance=202005121407&basin=atl&fdays=2 |website=National Hurricane Center |accessdate=May 17, 2020}}</ref> By May 13, thunderstorm activity began to increase in association with a developing [[Trough (meteorology)|Trough]] near the western tip of Cuba, and the NHC considered the developing system to have a 70% chance of subtropical formation in the next 5 days.<ref>{{cite web |title=Special Tropical Weather Outlook Special Tropical Weather Outlook |url=https://www.nhc.noaa.gov/archive/xgtwo/gtwo_archive.php?current_issuance=202005131244&basin=atl&fdays=2 |website=National Hurricane Center |accessdate=May 17, 2020}}</ref> Several hours later, the trough had fully developed south of the [[Florida Keys]] and began to spread disorganized shower and thunderstorm activity across the region.<ref>{{cite web |title=Special Tropical Weather Outlook 725 PM EDT Wed May 13 2020 |url=https://www.nhc.noaa.gov/archive/xgtwo/gtwo_archive.php?current_issuance=202005132325&basin=atl&fdays=2 |website=National Hurricane Center |accessdate=May 17, 2020}}</ref> A day later, the system was given a medium chance of becoming a subtropical or possibly fully tropical cyclone in the next 48 hours.<ref>{{cite web |title=Special Tropical Weather Outlook 830 AM EDT Thu May 14 2020 |url=https://www.nhc.noaa.gov/archive/xgtwo/gtwo_archive.php?current_issuance=202005141255&basin=atlc&fdays=2 |website=National Hurricane Center |accessdate=May 17, 2020}}</ref> The disturbance began to accelerate eastward as conditions were deemed very favorable for at least some degree of subtropical cyclogenesis.<ref name="NearDevelopment">{{cite web |title=Special Tropical Weather Outlook 240 PM EDT Thu May 14 2020 |url=https://www.nhc.noaa.gov/archive/xgtwo/gtwo_archive.php?current_issuance=202005141839&basin=atl&fdays=2 |website=National Hurricane Center |accessdate=May 17, 2020}}</ref> At this time, the NHC scheduled a [[Hurricane Hunter]] aircraft to investigate the system by the next day,<ref name="NearDevelopment"></ref> however it was later cancelled at the time it was scheduled due to a lack of organization of the storm's convective activity.<ref>{{cite web |title=Special Tropical Weather Outlook 850 AM EDT Fri May 15 2020 |url=https://www.nhc.noaa.gov/archive/xgtwo/gtwo_archive.php?current_issuance=202005151327&basin=atl&fdays=2 |website=National Hurricane Center |accessdate=May 17, 2020}}</ref> Convection began to slowly build around the center by early May 16, and a well-defined low-level circulation (LLC) began to form displaced just slightly east of the main thunderstorms.<ref>{{Cite web|title=NHC Graphical Outlook Archive|url=https://www.nhc.noaa.gov/archive/xgtwo/gtwo_archive.php?current_issuance=202005161212&basin=atl&fdays=5|website=www.nhc.noaa.gov|access-date=2020-05-17}}</ref> The NHC in response to this increase of development sent a group of reconnaissance planes to investigate the system. During this flight, a well-defined circulation center was found with 30 kt (35 mph, 55 km/h) winds mostly wrapped around the circulation, allowing the NHC to upgrade the low to Tropical Depression One, the first storm of the season, at 5:00 PM EDT on May 16.<ref name=":0">{{Cite web|title=Tropical Depression One Discussion Number 1|url=https://www.nhc.noaa.gov/archive/2020/al01/al012020.discus.001.shtml?|last=Cangialosi|first=John|date=|website=National Hurricane Center|url-status=live|archive-url=|archive-date=|access-date=May 17, 2020}}</ref> The system was considered tropical instead of subtropical in nature due to persisting central deep convection and a tight radius of winds.<ref name=":0" />

Several hours after designation as a tropical depression, the NHC sent another group of Hurricane Hunter aircraft to investigate the system further. According to reconnaissance, tropical storm-force winds had been confirmed to have sustained east and southeast of the center of circulation.<ref>{{Cite web|title=URNT12 KNHC 170014 VORTEX DATA MESSAGE AL012020|url=https://www.nhc.noaa.gov/archive/recon/2020/REPNT2/REPNT2-KNHC.202005170014.txt|last=|first=|date=|website=National Hurricane Center|url-status=live|archive-url=|archive-date=|access-date=May 17, 2020}}</ref> With this data in mind, the NHC upgraded the system to Tropical Storm Arthur at 11:00 PM EDT on May 17, making Arthur the first named storm of the season.<ref>{{Cite web|title=Tropical Storm Arthur Discussion Number 2|url=https://www.nhc.noaa.gov/archive/2020/al01/al012020.discus.002.shtml?|last=Stewart|first=Stacy|date=|website=National Hurricane Center|url-status=live|archive-url=|archive-date=|access-date=May 17, 2020}}</ref> Being steered generally north-northeast for the next several hours, Arthur would remain well offshore of the coasts of Florida and Georgia.<ref>{{Cite web|title=Tropical Storm Arthur Intermediate Advisory Number 2A|url=https://www.nhc.noaa.gov/archive/2020/al01/al012020.public_a.002.shtml?|last=Pasch|first=Richard|date=|website=National Hurricane Center|url-status=live|archive-url=|archive-date=|access-date=May 17, 2020}}</ref> A mid-level trough centered over the United States caused Arthur to slowly be pushed northeastwards over a section of relatively cool waters and as a result most of the storm's convection became limited to the east of the circulation in the form of a well-defined band, while the rest of the circulation remained mostly exposed.<ref>{{Cite web|title=Tropical Storm Arthur Discussion Number 3|url=https://www.nhc.noaa.gov/archive/2020/al01/al012020.discus.003.shtml?|last=Pasch|first=Richard|date=|website=National Hurricane Center|url-status=live|archive-url=|archive-date=|access-date=May 17, 2020}}</ref> Despite these unfavorable conditions, reconnaissance aircraft found Arthur slightly stronger with 48 kt flight-level winds and 37 kt near-surface winds, despite its appearance on satellite degrading significantly throughout the past few hours.<ref>{{Cite web|title=Tropical Storm Arthur Discussion Number 4|url=https://www.nhc.noaa.gov/archive/2020/al01/al012020.discus.004.shtml?|last=Brown|first=Daniel|date=|website=National Hurricane Center|url-status=live|archive-url=|archive-date=|access-date=May 18, 2020}}</ref> Little would change in Arthur's intensity and appearance until it moved on top of the warmer waters of the [[Gulf Stream]], where deep convection began to swiftly re-develop over the center.<ref name="Intensification">{{Cite web|title=Tropical Storm Arthur Discussion Number 8|url=https://www.nhc.noaa.gov/archive/2020/al01/al012020.discus.008.shtml?|last=Brown|first=Daniel|date=|website=National Hurricane Center|url-status=live|archive-url=|archive-date=|access-date=May 18, 2020}}</ref> In addition to a re-development in convection, Arthur intensified more to a minimum central pressure of 991 mb and with sustained winds of 45 kt (50 mph, 80 km/h).<ref name="Intensification></ref> As Arthur intensified, it's center skirted the coast of the [[Outer Banks]] in North Carolina, passing a mere 20 miles southeast from [[Cape Hatteras]].<ref>{{Cite web|title=Tropical Storm Arthur Advisory Number 8|url=https://www.nhc.noaa.gov/archive/2020/al01/al012020.public.008.shtml?|last=Brown|first=Daniel|date=|website=|url-status=live|archive-url=|archive-date=|access-date=May 18, 2020}}</ref> This was one of the earliest tropical cyclone impacts to the United States since [[Tropical Storm Ana (2015)|Tropical Storm Ana]] of [[2015 Atlantic hurricane season|2015]].<ref>{{Cite news|last=|first=|date=|title=Tropical Storm Arthur Spreads Rain and Gusty Winds Into Eastern North Carolina and Southeast Virginia on Monday|work=The Weather Channel|url=https://weather.com/storms/hurricane/news/2020-05-18-tropical-storm-arthur-forecast-north-carolina-atlantic-ocean|url-status=live|access-date=}}</ref> As a ridge strengthened to the north, Arthur began to be shoved away from the North Carolina coast and an increase in southwesterly shear as well as the beginning of [[Extratropical cyclone|extratropical transition]] began to separate the storm's main convective activity away from the LLC.<ref>{{Cite web|title=Tropical Storm Arthur Forecast Discussion Number 9|url=https://www.nhc.noaa.gov/text/refresh/MIATCDAT1+shtml/182039.shtml|last=|first=|date=|website=www.nhc.noaa.gov|url-status=live|archive-url=|archive-date=|access-date=2020-05-18}}</ref> The storm completed this process by early May 19, and became an extratropical cyclone as a trailing warm front developed behind the now almost fully exposed LLC, where the last advisory was issued on the system well northwest of Bermuda.<ref>{{cite web |last1=Blake |first1=Eric |title=Post-Tropical Cyclone Arthur Discussion Number 12 |url=https://www.nhc.noaa.gov/text/refresh/MIATCDAT1+shtml/191446.shtml |website=National Hurricane Center}}</ref>

== Preparations and impact ==

=== Florida, Georgia and South Carolina ===

Although Arthur never directly impacted Florida as a tropical system, the precursor system to Arthur caused heavy rainfall and gusty winds in the [[Florida Keys]] and South Florida throughout May 13-14. Over 4 inches (101.6 mm) of rain fell in many sections of the [[Middle Keys]] and a peak rainfall total of 5.35 inches (135.8 mm) fell in [[Marathon, Florida|Marathon]] on May 14, where it was the tenth highest rainfall amount for the city on record and second most for May.<ref>{{Cite news|last=|first=|date=|title=First Depression or Storm of 2020 Atlantic Hurricane Season, Possibly Arthur, To Form Off Southeast Coast This Weekend|work=The Weather Channel|url=https://weather.com/storms/hurricane/news/2020-05-14-first-storm-2020-hurricane-season-arthur-possible|url-status=live|access-date=}}</ref><ref>{{Cite web|title=The rainfall record in #MarathonFL was crushed today! As of 6 pm, 5.35" had been recorded, which is over 4" more than the previous record of 1.20" set in 1988! It's also the 2nd wettest day in May and the 10th wettest day ever. #flwx #FloridaKeys #KeyWest #RecordRainfall #weatherpic.twitter.com/SosQ92zOpm|url=https://twitter.com/NWSKeyWest/status/1261059206402109440/photo/1|date=2020-05-14|website=@NWSKeyWest|language=en|url-status=live|archive-url=|archive-date=|access-date=2020-05-18}}</ref> [[Flash flood warning|Flash flood warnings]] were issued for large portions of [[Miami-Dade County, Florida|Miami-Dade County]] on May 14, where street flooding was reported.<ref>{{Cite web|title=Arthur, the first named storm of the hurricane season, could form Saturday|url=https://www.cnn.com/2020/05/15/weather/tropical-storm-arthur-forecast-weekend-friday/index.html|last=Meteorologist|first=Allison Chinchar, CNN|website=CNN|access-date=2020-05-18}}</ref> Tropical storm-force wind gusts as well as [[Waterspout|waterspouts]] caused [[Gale warning|gale warnings]] and [[Special marine warning|special marine warnings]] to be issued across the majority of [[South Florida]].<ref>{{Cite web|title=Flood and wind advisories issued for South Florida, and the storms could spawn tornadoes|url=https://www.miamiherald.com/news/weather-news/article242757876.html|last=Cohen|first=Howard|date=|website=The Miami Herald|url-status=live|archive-url=|archive-date=|access-date=May 18, 2020}}</ref> [[Rip current|Rip currents]] in Florida led to the water rescues of 70 people in [[Volusia County, Florida|Volusia County]], 3 of which who were hospitalized.<ref>{{Cite web|title=This year's first Atlantic storm Arthur will bring high surf, strong winds and heavy rains to the North Carolina coast|url=https://www.wrcbtv.com/story/42140100/this-years-first-atlantic-storm-arthur-will-bring-high-surf-strong-winds-and-heavy-rains-to-the-north-carolina-coast|website=www.wrcbtv.com|language=en|access-date=2020-05-18}}</ref> Purple and red flags were raised along the coasts of Georgia and South Carolina to alert the public for rip currents and dangerous surf conditions.<ref>{{Cite web|title=Tropical Storm Arthur Churning Off Georgia Coast|url=https://atlanta.cbslocal.com/2020/05/18/tropical-storm-arthur-churning-off-georgia-coast/|date=2020-05-18|language=en-US|access-date=2020-05-18}}</ref> 3-6 ft (0.9-1.8 m) high waves occurred off the coast of Georgia on May 17.<ref>{{Cite web|title=Wetter weather returns this week!|url=https://www.wtoc.com/2020/05/17/wetter-weather-returns-this-week/|website=www.wtoc.com|access-date=2020-05-18}}</ref>

=== Cuba and the Bahamas ===

Reports of heavy rain occurred in the northern portions of [[Granma Province]] in Cuba throughout May 15 due to the broad system.<ref name=":1">{{Cite web|title=Lluvias intensas provocan inundaciones en Bayamo|url=https://adncuba.com/noticias-de-cuba/actualidad/lluvias-intensas-provocan-inundaciones-en-bayamo|website=ADN Cuba|language=es|access-date=2020-05-18}}</ref> Media of flooded streets and homes showed significant damage in certain areas of the province, where 78 mm (3.07 in) of rainfall fell in [[Bayamo]] in only 4 hours.<ref name=":1"></ref> In the Bahamas, [[squall]] conditions occurred on [[Grand Bahama]] island, where many were still recovering from the adverse effects of [[Hurricane Dorian]]. Gusty winds damaged tents and other temporary shelters across the island, and rainfall caused some minimal flooding.<ref>{{Cite web|title=Tropical weather conditions expected to hit Grand Bahama|url=http://www.tribune242.com/news/2020/may/15/tropical-weather-conditions-expected-to-hit-grand/|website=www.tribune242.com|language=en|access-date=2020-05-18}}</ref> Impacts were relatively limited, since the strongest winds of the disturbance were located to the east of the center which was hundreds of miles north of the island.<ref>{{Cite web|title=Messy system near South Florida still forecast to organize|url=https://www.local10.com/weather/2020/05/15/messy-system-near-south-florida-still-forecast-to-organize/|last=Norcross|first=Bryan|date=2020-05-15|website=WPLG|language=en|access-date=2020-05-18}}</ref>

=== North Carolina ===

On May 16, Tropical Storm Watches were issued from [[Surf City, North Carolina|Surf City]] to [[Duck, North Carolina|Duck]] and [[Pamlico Sound]] to [[Albemarle Sound]] with the designation of Tropical Depression One.<ref>{{Cite web|title=Tropical Depression One Advisory Number 1|url=https://www.nhc.noaa.gov/archive/2020/al01/al012020.public.001.shtml?|last=Cangialosi|first=John|date=|website=|url-status=live|archive-url=|archive-date=|access-date=}}</ref> A day later, these watches were upgraded to tropical storm warnings as Arthur moved closer towards the [[Outer Banks]].<ref>{{Cite web|title=Tropical Storm Arthur Advisory Number 3|url=https://www.nhc.noaa.gov/archive/2020/al01/al012020.public.003.shtml?|last=|first=|date=|website=|url-status=live|archive-url=|archive-date=|access-date=}}</ref> By late May 17, rough surf conditions were already being experienced on the southern portion of the Outer Banks.<ref name=":2">{{Cite web|title=Tropical Storm Arthur crawls closer to North Carolina coast|url=https://www.nbcnews.com/news/weather/tropical-storm-arthur-crawls-closer-north-carolina-coast-n1209031|last=|first=|date=|website=The Associated Press|url-status=live|archive-url=|archive-date=|access-date=}}</ref> The National Weather Service also noted that storm surge could cause some coastal flooding and dangerous marine conditions.<ref name=":2"></ref> Governor [[Roy Cooper]] urged all residents in Eastern North Carolina to keep "very aware" on the storm, and that you shouldn't "take any chances" with the rough sea conditions.<ref>{{Cite web|title=Gov. Cooper urges caution as Tropical Storm Arthur approaches NC coast|url=https://myfox8.com/news/gov-cooper-urges-caution-as-tropical-storm-arthur-approaches-nc-coast/|last=|first=|date=|website=Fox 8 News|url-status=live|archive-url=|archive-date=|access-date=}}</ref>

[[File:Tropical Storm Arthur on Radar.jpg|thumb|Arthur on its closest approach to North Carolina on radar on May 18]]

On May 18, Arthur began to scrape the southern North Carolina coast, where the National Hurricane Center warned of life-threatening inundation.<ref>{{Cite web|title=Tropical Storm Arthur expected to brush North Carolina, bring "life-threatening surf"|url=https://myfox8.com/news/tropical-storm-arthur-expected-to-brush-north-carolina-cause-possible-life-threatening-surf/|last=|first=|date=|website=Fox 8 News|url-status=live|archive-url=|archive-date=|access-date=}}</ref> Torrential rainfall occurred as Arthur's outer rainbands scraped eastern North Carolina.<ref name=":3">{{Cite news|last=Cappucci|first=Matthew|date=2020-05-18|title=Tropical Storm Arthur lashes Outer Banks with heavy rain, high surf|language=en-US|work=Washington Post|url=https://www.washingtonpost.com/weather/2020/05/18/tropical-storm-arthur-lashes-outer-banks-with-heavy-rain-high-surf/|access-date=2020-05-18|issn=0190-8286}}</ref> 4.92" of rain fell in [[Newport, North Carolina|Newport]], NC within 6 hours, and many other locations recorded atleast 3" of rain from the storm.<ref>{{Cite web|title=Public Information Statement: PRECIPITATION REPORTS 1055 AM EDT Mon May 18 2020|url=https://forecast.weather.gov/product.php?site=NWS&issuedby=MHX&product=PNS&format=CI&version=3&glossary=0|last=|first=|date=|website=National Weather Service|url-status=live|archive-url=|archive-date=|access-date=}}</ref> Tropical storm-force wind gusts in [[Cape Hatteras]] were also recorded, but most of the higher sustained winds remained offshore due to Arthur's lopsided nature.<ref>{{Cite web|title=Public Information Statement: HIGHEST WIND REPORTS 237 PM EDT Mon May 18 2020|url=https://forecast.weather.gov/product.php?site=NWS&issuedby=MHX&product=PNS&format=CI&version=1&glossary=0|last=|first=|date=|website=National Weather Service|url-status=live|archive-url=|archive-date=|access-date=}}</ref><ref name=":3"></ref> Other sections of [[Carteret County, North Carolina|Carteret County]] in North Carolina recorded at least 4-5 inches of rain on May 18.<ref>{{cite web |title=Daily Precipitation Map 5/18/2020 Carteret County, NC |url=https://www.cocorahs.org/Maps/ViewMap.aspx?state=usa |website=CoCoRaHS}}</ref> Wave heights as high as 12.5 ft (3.8 m) were recorded from buoys along the coast of the Outer Banks from Arthur.<ref>{{cite news |title=Tropical Storm Arthur flirts with landfall over NC Outer Banks |url=https://www.accuweather.com/en/hurricane/tropical-storm-arthur-makes-close-approach-to-north-carolina/741838?utm_campaign=breakingweather&utm_medium=social&utm_source=twitter&utm_content=1589816192 |issue=May 18, 2020 |publisher=AccuWeather}}</ref> Due to flooding from Arthur, many highways in the Outer Banks and into mainland North Carolina were closed.<ref>{{cite news|last=|first=|date=|title=Tropical Storm Arthur hits North Carolina coast with rain|work=The Sun Sentinel|url=https://www.sun-sentinel.com/news/weather/hurricane/fl-ne-ap-tropical-storm-arthur-north-carolina-20200518-wxgkdryzyvf2hnyajdkmraykua-story.html|url-status=live|access-date=}}</ref> [[SpaceX]] was also forced to delay the launch of several [[Starlink]] internet satellites due to adverse weather from Arthur affecting the recovery fleet.<ref>{{Cite web|title=SpaceX postpones Starlink satellite fleet launch due to Tropical Storm Arthur|url=https://www.space.com/spacex-starlink-launch-delayed-by-tropical-storm-arthur.html|last=May 2020|first=Chelsea Gohd 18|website=Space.com|language=en|access-date=2020-05-18}}</ref> As Arthur moved away from the coast, tropical storm warnings were lifted as conditions gradually improved later in the evening.<ref>{{Cite news|last=|first=|date=|title=Tropical storm warning lifted as Arthur moves away from North Carolina's Outer Banks|work=The News & Observer|url=https://www.newsobserver.com/news/state/north-carolina/article242796541.html|url-status=live|access-date=}}</ref>

== See also ==

* [[Tropical Storm Arthur|Other tropical cyclones named Arthur]]

* [[Hurricane Arthur|Hurricane Arthur (2014)]] – took a similar track and made a landfall in a similar location

* [[Tropical Storm Ana (2015)]] – made landfall at a similar time

* [[Tropical Storm Arthur (1996)]] – another storm with the same name and a similar track

* [[Tropical Storm Beryl (2012)]] – the strongest storm to make landfall in the United States in May

* [[List of North Carolina hurricanes]]

* [[List of off-season Atlantic hurricanes]]

== References ==

<!--- See http://en.wikipedia.org/wiki/Wikipedia:Footnotes on how to create references using <ref></ref> tags, these references will then appear here automatically -->

{{Reflist}}

<!--- Categories --->

{{DEFAULTSORT:Arthur}}

[[Category:Off-season Atlantic tropical cyclones]]

[[Category:Hurricanes in North Carolina]]

[[Category:May 2020 events in the United States]]

[[Category:Atlantic tropical storms]]

[[Category:Tropical cyclones in 2020]]