Heavy Snow — Bertie, North Carolina

2025-01-21 to 2025-01-22 · Bertie, North Carolina

Event narrative

Snowfall totals generally ranged from 3 to 5 inches across Bertie County. A snowfall total of 4.5 inches was reported in Merry Hill.

Wider weather episode

At the surface, the center of a strong arctic high (1040mb) extending from the central CONUS to the East Coast gradually moved from the Mississippi Valley on January 21 to the East Coast on January 22. Meanwhile, an area of low pressure formed in central Gulf along a stationary front extending from the central Gulf to offshore of the East Coast. Aloft, a sharpening but positively tiled shortwave trough crossed the area during the evening of the January 21 through the early morning of January 22. A very cold and dry low-level Arctic airmass was in place over the entire area with temperatures in the lower-mid 20s (with dew points around 0F) during the afternoon on January 22 before any snow had started to fall. Even though the surface low tracked well to the southeast of the area, mid to upper level forcing for ascent was strong given decent warm air advection aloft. The sloping mid to upper level frontogenesis zone was over the area, with the strongest frontogenesis in the dendritic growth zone (700-550mb) residing over southeast Virginia during the evening into early overnight hours on January 21. Despite the very cold and dry antecedent airmass, light snow began falling as far west as the Richmond Metro by 7 PM. The low-levels then quickly saturated area-wide by 8-9 PM. Most of the snow was light in intensity, but a band of moderate to heavy snow (likely with 1-2'/hour rates) set up across extreme southeast Virginia and northeast North Carolina on the warm side of the mid-level frontogenesis zone. In addition, given the very cold temperatures (and forcing for ascent concentrated in the dendritic growth zone), snow-to-liquid ratios were 15-20:1 even across northeast North Carolina. Also, given the cold low-level temperatures (925mb temperatures of -13 to -16C) and the northerly flow, some additional enhancement of the snow was observed across Norfolk into portions of interior northeast North Carolina due to moisture flow off the bay. The steady snow ended between midnight and 4 AM on January 22 as the shortwave quickly pushed offshore, but totals across northeast North Carolina ranged from 3-7 inches (locally 8 inches). Southern portions of Hampton Roads saw around 3 inches, with localized totals around 4 inches in that area of Norfolk that saw bay-enhanced snow. After the steady synoptic snow ended, a bay-effect snow band developed given minimal shear from the surface to 900mb (with the top of that layer in the dendritic growth zone). In addition, the difference between the water temperature (38F/3C) and the 900mb temperature (around -15C) was more than enough for a few hundred J/kg of bay-induced instability. This combination of factors set the stage for a true bay effect snow event that likely produced localized snow totals of 0.5 inches on top of what had already fallen. The bay effect band drifted west and weakened by 5-6 AM as the fetch over the bay was disrupted with the low-level flow shifting from due north to north-northeast. However, another band of bay-effect snow showers developed from late morning into the afternoon on January 22 near the Norfolk area before tapering off.

Source: NOAA Storm Events Database, event_id 1234123. Narrative written by the NWS forecast office that issued the report.