An area of low pressure tracked along a stalled frontal zone to the south of central NC and eventually north-northeastward along the North Carolina coast. Meanwhile, strong surface high pressure extended south-southwestward and into central North Carolina from the northeast United States.
Every event with a place to put it; 15 filed by county or forecast zone are drawn at its center, in a lighter ring. Tap one for its entry below.
Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.
The episode as NWS RAH wrote it up.
An area of low pressure tracked along a stalled frontal zone to the south of central NC and eventually north-northeastward along the North Carolina coast. Meanwhile, strong surface high pressure extended south-southwestward and into central North Carolina from the northeast United States. This setup resulted in widespread precipitation developing on the morning of the 12th and continuing into the 13th, with a cold air damming airmass developing. This allowed for temperatures to evaporatively cool, with temperatures falling below freezing across the northern Piedmont and northern Coastal Plain. This allowed for freezing rain to occur in this area. Ice accrual range from trace amounts to a couple of hundredths of an inch around the Triangle area, to a quarter to a half inch of ice accrual in Triad region and along/near the North Carolina-Virginia border. Impacts were limited to the Triad and North Carolina-Virginia border counties, where numerous accidents, power outages, and tress down were reported.
The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS Raleigh, NC wrote its last area forecast discussion before the first event at Feb 11, 9:47 PM EST, 3 hours 13 minutes earlier.
AREA FORECAST DISCUSSION National Weather Service Raleigh NC 947 PM EST Thu Feb 11 2021 .SYNOPSIS... Surface high pressure will wedge south down the eastern seaboard through the weekend. At the same time, a series of surface lows will develop and move along a stalled boundary extending across the southeast US through the weekend. && .NEAR TERM /THROUGH FRIDAY/... As of 945 PM Thursday... ...Winter Weather Advisory in effect through noon Saturday for the northern Piedmont and Coastal Plain... No significant changes made to the forecast for Friday and only a small tweak to the temps to blend with current obs. Otherwise, forecast remains the same and on track from this afternoon issuance. As of 02Z the surface high has built into central NC from the north, resulting in caa from the northeast. A steady drop in temperatures is still expected tonight, bottoming out around 31/32 degrees along and north of I-85 to mid/upper 30s south and east of I-95. Of course, if and how much freezing rain occurs/accumulates in the next 12 hours or so will depend on the temperature and continued precipitation. With the temperatures mentioned above, still expect at least a glaze with up to a tenth of an inch possible along the VA/NC border through Friday morning. Previous Discussion (As of 350 PM Thursday)... A recurring theme over the next 2 to 3 days will a very active and perturbed southern stream flow that will fuel periods of moderate precip across the region. Two such disturbances have/are currently tracking across the region and is responsible for some widely scattered elevated thunder. Additional disturbances will track through the region through late tonight. Expect a very wet and soggy afternoon compute, evening and overnight period with total rainfall amounts expected to average 0.75 to 1.25" across central NC, with some locally higher of 1.75" possible. The 12z/11 guidance has come in a touch colder. Renewed CAA will cool temperatures to near freezing(31-32F)across the far northern zones to upper 30s/near 40 south. Across the northern counties, temperatures are expected to hover right around freezing through mid to late morning, before rising to just above freezing by noon/early afternoon. These marginally freezing temperatures will support a period of light freezing rain/freezing drizzle and then drizzle across the far northern/Va bordering counties through late morning as the main area of precipitation shifts east of the area by early afternoon. Elsewhere it will be a cold rain. Ice accumulations are expected to range from a trace along the I-85 corridor to between 0.05 to 0.10" north of I-85, along the Virginia bordering counties. The bulk of the ice accrual should remain confined to elevated surfaces. But climatology suggests that more times than not, our far northern Va bordering counties usually over perform in terms of ice/snow accumulation. So, we could see patchy slick spots develop on bridges and overpasses. Thus, have decided to issue a Winter Weather Advisory for Person, Granville, Vance, Warren and Halifax counties tonight through noon Friday. Expect only a 2 to 3 degree recovery in temps throughout the day on Friday. Highs ranging from lower/mid 30s north to lower 40s SE. && .SHORT TERM /FRIDAY NIGHT THROUGH SATURDAY NIGHT/... As of 350 PM Wednesday... ...Winter Weather Advisory for the northern Piedmont and coastal plain counties through noon Saturday... With a mature CAD in place, modified cP airmass will remain in place as the energetic and perturbed southern stream will give rise to yet another coastal low development off the SE and NC coast. Models have trended slightly slower with the next wave/surge of moisture, lift, and precip into the area late Friday night/early Saturday morning. Given that marginally near sfc temps of 31 to 32 F expected across the far norther Piedmont, this slight delay in the higher precip amounts is critical to the forecast, as ice accrual will be more conducive at night, before the sun rises and the temps rise to or just above freezing. Saturday and Saturday night will be another soaker, with another 0.75-1.25" of liquid precip overspreading the area. May need to expand the Winter Weather Advisory a row of counties to the south. The bulk of the ice accrual will likely occur early Saturday morning and again Saturday evening/early Sunday morning. Ice accumulation of a trace to 0.2" of an inch are possible across the far northern zones, I-85 corridor. South of I-85 corridor, predominate p-type will fall as a cold rain. Lows Friday night and again Saturday night ranging around freezing across the north to mid/upper 30s south. Highs Saturday in the lower/mid 30s north to near 40 south. && .LONG TERM /SUNDAY THROUGH THURSDAY/... As of 320 PM Thursday... Active pattern continues into the latter half of the weekend/early next week, with broad southwesterly flow across the region and a weak embedded shortwave trough forecast to move through the Southeast Sunday afternoon. Both the EC and GFS and their respective ensembles indicate increasing rain chances during the day Sunday as this wave moves from FL off the SC coast and east of NC during the day, with the highest precip chances along and east of US-1. Fortunately, P-type should not be an issue with this event despite modest onshore flow/northeast winds and +5 to +7C temperatures at 850mb. As the wave departs Sunday night, some cooler air will drain into the area from the north. Will be a race to see how quickly precip comes to an end vs arrival of BL cold air from the north. I have a few hours of freezing rain in the forecast right along the NC/VA border from Person to Halifax Co early Monday morning but impacts (if any) will be limited. Looking at Monday, this period was the source of considerable uncertainty days ago and there are still some differences among the major players, albeit it less than what was seen a few days ago. As an upper wave ejects out of the Rockies, it will deepen on Monday and move into the Ohio Valley Tuesday morning. Both EC and GFS indicate a Miller-B type setup with the main upper low moving into the Great Lakes with a weak secondary surface low forming off the coast. With a surface ridge to the north, we should have a decent supply of drier/cooler air available to start the event and there is a chance rain/freezing rain across the northern tier counties early Tuesday morning. However the upper low and associated forcing for ascent will rapidly move northward through the day with a noteworthy drying trend in the models noted by 18Z Tuesday, not to mention a brief period where temps could potentially warm up significantly into the 60s across the Coastal Plain (the NW Piedmont will likely stay socked in with highs barely getting to 40). Any mention of FZRA in the forecast will be confined to the northern counties north of I- 85 and quickly removed by late morning as temps warm above the freezing mark. Elsewhere temps will be marginal for FZRA with early morning lows only reaching the mid 30s. Tuesday night as the surface low moves off shore of the northern Mid- Atlantic, there could be some lingering scattered showers over the Coastal Plain. High pressure over the Ohio Valley will build north and east of NC bringing in cooler temperatures with lows in the low 30s across the NW and upper 30s across the SE. Wednesday morning as the upper level trough over the Rockies deepens over the Four Corners a upper level ridge builds over the Ohio Valley. Finally after numerous days of multiple rounds of disturbances moving across the area we will have a break and dry out Wednesday before yet another disturbance moves up from the Gulf and across Central NC. Wednesday night the upper level trough moves into the southern Central Plains and begins to bring lift and moisture back into our region late Wednesday night. Long range models begin to diverge with the GFS bringing an abundance of moisture into the area Wednesday night, where as the ECMWF keeps things dry a little longer. Currently have increasing slight chance PoPs beginning Wednesday night from the SW and increasing into Thursday morning. Both deterministic models, and the majority of GEFS and EC ensemble members agree that by late Thursday morning the surface low pressure will have moved from the Gulf up along the Appalachians bringing precipitation into the entire CWA. The aforementioned low brought warm moist air from the Gulf resulting in lows Wednesday night/Thursday morning to be in the mid/upper 30s across the area and continue the warming pattern with highs in the 50s Thursday, thus all precipitation for Thursday and into Thursday night will be liquid for this event. && .AVIATION /00Z FRIDAY THROUGH TUESDAY/... As of 635 PM Thursday... 24 hour TAF period: High confidence aviation conditions will remain sub-VFR through the TAF period. Widespread IFR cigs and MVFR vsbys will persist through tonight as rain continues across central NC. Northeasterly winds will remain around 10 kts, with intermittent gusts of 15-18 kts through Friday. Do not expect any more thunder at the central NC terminals tonight, though if it were to occur it would be at KFAY. Still expect a chance for some FZRA/FZDZ along and north of I-85 (KINT/KGSO) in the 08Z to 12Z Friday time frame, though better chances will be points a bit farther east and north. Rain should move out of the area Friday morning/early afternoon, with visbys returning to VFR (except for KRWI which may remain MVFR through 00Z Saturday), but cigs remaining IFR/MVFR through much if not all of the remainder of the TAF period. -KC Looking ahead: Ceilings and visibilities will likely remain sub-VFR through Tuesday. Another wave of rain will develop early Saturday, with freezing rain again possible at GSO/INT. Another break in unsettled weather takes hold Sunday, before another round of sub-VFR precipitation develops Monday through Tuesday. -Kren && .RAH WATCHES/WARNINGS/ADVISORIES... Winter Weather Advisory from midnight tonight to noon EST Saturday for NCZ007>011. && SYNOPSIS...KC/CBL NEAR TERM...KC/CBL SHORT TERM...CBL LONG TERM...Leins/CA AVIATION...KC/Kren
Hazardous Weather Outlook National Weather Service Raleigh NC 410 PM EST Thu Feb 11 2021 NCZ007>011-121300- Person-Granville-Vance-Warren-Halifax- 410 PM EST Thu Feb 11 2021 ...WINTER WEATHER ADVISORY IN EFFECT FROM MIDNIGHT TONIGHT TO NOON EST SATURDAY... This Hazardous Weather Outlook is for central North Carolina. .DAY ONE...Tonight. Please listen to NOAA Weather Radio or go to weather.gov on the Internet for more information about the following hazards. Winter Weather Advisory. .DAYS TWO THROUGH SEVEN...Friday through Wednesday. Please listen to NOAA Weather Radio or go to weather.gov on the Internet for more information about the following hazards. Winter Weather Advisory. .SPOTTER INFORMATION STATEMENT... Spotter activation is not expected at this time. NCZ021>026-038>041-121300- Forsyth-Guilford-Alamance-Orange-Durham-Franklin-Davidson-Randolph- Chatham-Wake- 410 PM EST Thu Feb 11 2021 This Hazardous Weather Outlook is for central North Carolina. .DAY ONE...Tonight. Hazardous weather is not expected at this time. .DAYS TWO THROUGH SEVEN...Friday through Wednesday. A brief period of light freezing rain is possible late Friday night and early Saturday. Rain is expected to possibly mix with or change to light freezing rain late Friday night as temperatures fall into the lower 30s. Any icing should be limited to elevated surfaces where the temperatures fall below freezing. Some spotty slick spots may develop especially on elevated bridges and overpasses centered between 500 am and 900 am Saturday. Rain and slowly rising temperatures into the mid 30s should end the icing threat by late Saturday morning. .SPOTTER INFORMATION STATEMENT... Spotter activation is not expected at this time. NCZ027-028-042-043-073>078-083>086-088-089-121300- Nash-Edgecombe-Johnston-Wilson-Stanly-Montgomery-Moore-Lee-Harnett- Wayne-Anson-Richmond-Scotland-Hoke-Cumberland-Sampson- 410 PM EST Thu Feb 11 2021 This Hazardous Weather Outlook is for central North Carolina. .DAY ONE...Tonight. No hazardous weather is expected at this time. .DAYS TWO THROUGH SEVEN...Friday through Wednesday. No hazardous weather is expected at this time. .SPOTTER INFORMATION STATEMENT... Spotter activation is not expected at this time.
The national radar mosaic for the moment the first event began.
9 winter weather, 6 winter storm. Local standard time, as filed.
One-quarter to one-half of an inch of ice from freezing rain downed numerous trees across the county, causing numerous power outages.
One-quarter to one-half of an inch of ice from freezing rain downed numerous trees across the county, causing numerous power outages.
One-quarter to one-half of an inch of ice from freezing rain downed numerous trees across the county, causing numerous power outages.
One-quarter to one-half of an inch of ice from freezing rain downed numerous trees across the county, causing numerous power outages.
One-quarter to one-half of an inch of ice from freezing rain downed numerous trees across the county, causing numerous power outages.
One-quarter to one-half of an inch of ice from freezing rain downed numerous trees across the county, causing numerous power outages.
A trace to one-tenth of an inch of ice from freezing rain was reported across the county.
A trace to one-tenth of an inch of ice from freezing rain was reported across the county, with the most ice accrual reported across northern portions of the county.
A trace to one-tenth of an inch of ice from freezing rain was reported across the county, with the most ice accrual reported across northern portions of the county.
A trace to one-tenth of an inch of ice from freezing rain was reported across the county, with the most ice accrual reported across northern portions of the county.
One-tenth of an inch to two-tenths of inch of ice from freezing rain was reported across the county, with the most ice accrual reported across northern portions of the county.
A trace to one-tenth of an inch of ice from freezing rain was reported across the county, with the most ice accrual reported across northern portions of the county.
A trace to one-tenth of an inch of ice from freezing rain was reported across the county, with the most ice accrual reported across northern portions of the county.
A trace to one-tenth of an inch of ice from freezing rain was reported across the county, with the most ice accrual reported across northern portions of the county.
A trace to couple hundredths of an inch of ice from freezing rain was reported across the county, with the most ice accrual reported across northern portions of the county.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in North Carolina in 2021Every state in 2021This day in weather historyWarnings in North Carolina, February 2021
NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 946391, 946392, 946393, 946394, 946395, 946396, 946397, 946398, 946408, 946412, 946414, 946406, 946407, 946416, 946401.