A strong mid-level
shortwave moved out of the Desert Southwest and progressed eastward taking
on a bit more of a neutral tilt as it crossed east Texas late Thursday
evening February 11th (Figure 2) as surface low development occurred across
the western Gulf of Mexico. Widespread snow developed from east Texas
across central and northern sections of Louisiana and Mississippi Thursday
evening. Dallas, TX had a record storm total snowfall of 12.6 inches. As the storm progressed eastward,
widespread 6 to 8 inch snow amounts were noted over central and northern Louisiana
and Mississippi Thursday night into early Friday morning February 12th.
Continued development of
the northern Gulf surface low, accompanied by intensification of a
mid-level jet streak over the western Gulf of Mexico, led to
increasing development of heavy
snow by Friday morning across parts of east central and southeast
Mississippi through parts of central and southern Alabama. Light snow accumulations were noted
as far south as Mobile, Alabama and the far western Florida Panhandle.
Another strong mid-level
shortwave over Louisiana and Mississippi continued east and increased lift
across Central Alabama through Central Georgia Friday afternoon (Figure 3).
As the surface low over the Gulf developed east and deepened toward evening
off the east coast of Florida, snowfall amounts of 3 to 6 inches were noted
over Central and Northern
Georgia and snow spread into much of South Carolina late Friday afternoon.
An intense vorticity maximum moved from southeastern Georgia and
lifted northeastward into the eastern Carolinas Friday evening (Figure
4). As the surface low crossed
Florida and moved up the coast, the vorticity
center resulted in deepening cyclogenesis off the South Carolina
coast. As the storm developed,
very impressive 7-8 mb hourly pressure falls were observed just off the
North Carolina coast Friday evening. Snow started to fall in the
Newport/Morehead City County Warning Area (CWA), between 8 and 9 pm (01z
and 02z) Friday evening February 12th.
Forecast soundings showed that snow developed in the favorable
temperature dendritic growth zone. A mesoscale
discussion from the Storm Prediction Center noted that “snow rates
around 1 inch were possible within heavier snow bands...and would possibly
persist for 3 to 6 hours. “
Figure 2. 500 mb Heights at 7 am February 12th showing
upper trough over eastern Texas.
Figure 3. Storm Prediction Center Composite Chart from Friday
Afternoon Feb 12th, 2010 showing area of moderate snow.
Figure 4. Storm Prediction Center Composite Chart from Friday Evening
February 12th shows strong Vorticity center moving offshore with
rapid strengthening of surface low pressure off the northeast Florida
The surface low deepened
and moved off the Carolina coast by early Saturday morning (Figure 5) with
the snowfall gradually ending from the west by mid morning as the low
accelerated away from the area. When skies cleared by Saturday afternoon,
visible satellite showed the widespread snow cover over the region (Figure
Figure 5. Surface Analysis at 7 am February 13th, 2010
showing deepening low pressure off the North Carolina coast.
Figure 6. Visible satellite imagery from Saturday February 13th
showing widespread snow cover across Eastern North Carolina.
NOAA Daily Weather Maps
Storm Prediction Center