A de-amplifying mid-level shortwave, interacting with a preceding sharp low level frontal zone across the area, produced 1 to 3 inches of wet snow across the northern Piedmont counties during the evening and early night hours of the 24th and 25th.
Every event with a place to put it; 11 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.
A de-amplifying mid-level shortwave, interacting with a preceding sharp low level frontal zone across the area, produced 1 to 3 inches of wet snow across the northern Piedmont counties during the evening and early night hours of the 24th and 25th.
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 Mar 24, 7:15 PM EST, 45 minutes earlier.
Area Forecast Discussion National Weather Service Raleigh NC 815 PM EDT Sat Mar 24 2018 .SYNOPSIS... An area of low pressure and upper level disturbance will move northwest to southeast over North Carolina through tonight. Chilly high pressure will build into the Carolinas from the north Sunday through Tuesday. This high will move to our southeast and off the coast Wednesday, bringing a warming trend. && .NEAR TERM /THROUGH TONIGHT/... As of 415 PM Saturday... Update: Based on new guidance, have expanded the winter weather advisory area to include northern portions of Alamance, Orange, and Durham counties for the potential for a half to a much as an inch of snow, mainly on grassy and elevated surfaces. The dampening mid level shortwave trough moving into IL will continue a SE motion, passing through the Carolinas late tonight into Sun morning. The associated surface low over SE MO will track SE along the strengthening low level frontal zone, moving toward SW NC tonight, followed by secondary cyclogenesis just off the SC coast late. Mostly light precip associated with a weak leading perturbation has spread across NC, and the initially high dewpoint depressions have begun to decrease as cloud bases lower. We've already seen a band of higher precip rates passing over the Triad produce a period of snow, despite wet bulb temps sitting just above freezing. That such cooling of the column is already occurring is concerning, in that it suggests that perhaps a larger area of the northern Piedmont may see a risk of snow bursts this evening into the overnight hours. It's expected that as the stronger forcing for ascent arrives this evening (including low level frontogenetic forcing, incoming mid level DPVA, and increasing upper divergence associated with the northwesterly jetlet moving from the W Ohio Valley through the Carolinas), precip rates will pick up, with any spotty areas filling in by mid evening. Where the rates are highest, dynamic cooling is likely to prompt a rain/snow mix to switch over to mostly snow, not unexpected given projections of a deep near freezing isothermal layer. Surface temps should in general stay just above freezing, however a period of surface cooling is apt to occur within the heaviest precip over the northern Piedmont, causing an accumulation of snow, primarily on grassy and elevated surfaces. But if snow comes down heavy enough, some accumulation on roads, especially bridges/overpasses, is not out of the question. Expect precip totals of around a half to one inch across central NC, with far northern Piedmont snowfall of one half to one inch, highest over northern portions of the advisory area. Once the mid level wave passes through late tonight, taking the heaviest precip to our east, temps should rebound a degree or two, such that icy roads won't be a big concern Sunday morning. Lows will be 31-38, again with the cooler readings occurring during the heavier precip in the predawn hours. -GIH && .SHORT TERM /SUNDAY THROUGH SUNDAY NIGHT/... As of 425 PM Saturday... The by-now-shearing shortwave trough will be exiting to our SE Sun morning, with the primary surface low dissolving to a weak inverted trough over the S Appalachians and the secondary surface low moving further offshore. Copious low level moisture will remain, particularly over the W and S CWA, although the chilly wedging surface high may allow for some low level drying over the NE CWA. Nevertheless, expect a cloudy to mostly cloudy and cool day over much of the area, and we may see lingering drizzle over the Piedmont, especially west sections. Highs 43-50. Nocturnal cooling with the wedge holding firm Sun night will prompt the low clouds to hold firm, especially over the S and W. Lows 30-37. -GIH && .LONG TERM /MONDAY THROUGH SATURDAY/... As of 200 PM Saturday... Longer range forecast remains on track with much warmer weather returning by mid week. Cold air advection will continue Monday as high pressure ridges down the Atlantic coast. The cool ridge holds through Tuesday, though gradually weakening and lifting north into New England. The surface high lifting out combined with a mid level ridge axis over the area edging east and offshore Tuesday night will result in deep SW return flow with strong warm air advection setting up early Wednesday and continuing into Thursday. Temperatures on Wednesday will rise into the 60s and then soar into the 70s on Thursday. While all of this is going on locally, a long wave trof will be deepening over the Plains, with strong frontogenesis stretching out of the Gulf northeastward into the Ohio Valley during the mid week. The mid level ridge just east of the area will block and slow down the eastward progression of this surface front, allowing deeper layer moisture advection into the area, with precipitable waters edging above 1.5 inches prior to the front's passage early Friday. A lot of favorable ingredients will be also be present which would support stronger shower and thunderstorm activity, which would most likely manifest as a line of strong convection immediately ahead of the front. Timing will be key, as just a little delay of frontal passage from Thursday night into Friday would add increased instability to the mix. Highs Friday will be in the mid 60s north to mid 70s south. Ridging builds in Friday night into Saturday with cooler and dry weather. Highs Saturday will range from 55 north to 65 south. && .AVIATION /00Z SUNDAY THROUGH THURSDAY/... As of 815 PM Saturday... The system producing widespread rain/snow will continue to affect our region through the night. The main bulk of the precipitation will be a mix of snow and rain in the NW and rain in the SE. Widespread IFR to LIFR CIGS and VSBYS can be expected through 09z/Sunday. The precipitation will taper off to light mist and drizzle between 09z and 12z, with lingering low CIGS/VSBYS through 18z/Sunday. Looking beyond 18z Sun, within the cool surface ridge wedging down into central NC, cigs will stay mostly MVFR at INT/GSO, with a trend to VFR elsewhere Sun afternoon. MVFR conditions should dominate at INT/GSO through Sun night, with VFR conditions elsewhere. By midday Mon, VFR conditions are expected areawide, although sub-VFR conditions may linger at INT/GSO. As the surface high builds overhead and then drifts SE midweek, VFR conditions should dominate, although there are signs that the Piedmont terminals may see periods of sub-VFR clouds Tue into Wed as moisture increases aloft. Cigs should be VFR Thu with a chance of showers areawide, within southwest flow ahead of the next approaching storm system. -GIH && .RAH WATCHES/WARNINGS/ADVISORIES... Winter Weather Advisory from 8 PM this evening to 5 AM EDT Sunday for NCZ007-008-021>025. && SYNOPSIS...Hartfield NEAR TERM...Hartfield SHORT TERM...Hartfield LONG TERM...mlm/Franklin AVIATION...Badgett/Hartfield
Hazardous Weather Outlook...UPDATED National Weather Service Raleigh NC 450 PM EDT Sat Mar 24 2018 NCZ009>011-026>028-038>041-043-250900- Vance-Warren-Halifax-Franklin-Nash-Edgecombe-Davidson-Randolph- Chatham-Wake-Wilson- 450 PM EDT Sat Mar 24 2018 This Hazardous Weather Outlook is for central North Carolina. .DAY ONE...Tonight. A brief mix of rain and wet snow is possible from late evening through the overnight hours. No accumulation on roads is expected. .DAYS TWO THROUGH SEVEN...Sunday through Friday. Hazardous weather is not expected at this time. .SPOTTER INFORMATION STATEMENT... Spotter activation is not expected at this time. NCZ007-008-021>025-250900- Person-Granville-Forsyth-Guilford-Alamance-Orange-Durham- 450 PM EDT Sat Mar 24 2018 ...WINTER WEATHER ADVISORY IN EFFECT FROM 8 PM THIS EVENING TO 5 AM EDT SUNDAY... 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...Sunday through Friday. Hazardous weather is not expected at this time. .SPOTTER INFORMATION STATEMENT... Spotter activation is not expected at this time. NCZ042-073>078-083>086-088-089-250900- Johnston-Stanly-Montgomery-Moore-Lee-Harnett-Wayne-Anson-Richmond- Scotland-Hoke-Cumberland-Sampson- 450 PM EDT Sat Mar 24 2018 This Hazardous Weather Outlook is for central North Carolina. .DAY ONE...Tonight. No hazardous weather is expected at this time. .DAYS TWO THROUGH SEVEN...Sunday through Friday. 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.
10 winter weather, 1 winter storm. Local standard time, as filed.
One to three inches of wet snow fell across the county, with the highest amounts|across the northern tier.
One inch of snow fell across the county.
One to one and one half inches of snow fell across northern portions of the county.
One inch of snow fell across northern portions of the county.
One inch of snow fell across northern portions of the county.
One inch of snow fell across northern portions of the county.
One inch of snow fell across northern portions of the county.
One inch of snow fell across northern portions of the county.
One to two inches of snow fell across the county.
One inch of snow fell across the county.
One to two inches of snow fell across the county.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in North Carolina in 2018Every state in 2018This day in weather historyWarnings in North Carolina, March 2018
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: 747238, 747271, 747279, 747280, 747281, 747283, 747285, 747293, 747287, 747290, 747292.