April 28, 2011 Tornadoes

Event Overview 

On the afternoon of April 28, 2011, strong thunderstorms moved across Eastern North Carolina producing 3 confirmed tornadoes and reports of large hail (Figure 1). The tornadoes destroyed a hog farm, damaged numerous other structures, and knocked down numerous trees in Duplin County, produced downed trees and power lines near Vanceboro in Craven County, and produced minor damage at Plymouth in Washington County. These storms were part of a larger complex of severe weather that produced over 100 tornadoes and more than 300 deaths the previous day over Mississippi, Alabama, Tennessee and Georgia. 

Figure 1. Severe Weather Reports from April 28, 2011

Synoptic Overview

A vigorous mid-level trough moved from the northern Plains April 27 to the Western Great Lakes by 12Z on April 28, 2011 (Figure 2). This advancing system was responsible for the worst tornado outbreak in the United States since 1974 with over 100 tornadoes and over 300 deaths reported on April 27. As result of the previous day’s tornado outbreak, awareness was high for tornadoes over the Region. As this system advanced eastward on the morningof April 28, deep moisture was advected north at 850 mb (Figure 3) with a 60 knot jet maximum poised just west of the area at 12Z. At the surface, a cold front pushed slowly across the state and was approaching from central North Carolina at 21Z (Figure 4), with very moist air over eastern North Carolina with dewpoint temperatures in the lower and middle 70s. Deep layer south to southwest wind shear and CAPE (Convective Available Potential Energy) values of 1000 to 2000 j/kg were enough to overcome the relatively weak mid level lapse rates. The 12Z Newport/Morehead City sounding (Figure 5) showed conditions favorable for tornadic development with 0 to 1 kilometer helicity values of 287 m²s², and a right-turning hodograph indicative of strong low-level wind shear. Conditions also favored large hail with the wet bulb zero height around 9570 feet.

The initial tornado report was from Warsaw in southwestern Duplin County and came in shortly after 3 pm (19Z) with the MHX radar showing strong rotation at the lowest levels (Figure 6). This same supercell thunderstorm would continue to the northeast and produce another tornado touchdown near Fort Barnwell in Craven County (Figure 7). A supercell that formed to the east of this storm would later produce a tornado with minor damage over Plymouth in Washington County.

Figure 2. 500 mb Analysis at 12Z April 28 showing a broad mid-level trough advancing east.

Figure 3. 850 mb Analysis at 12Z April 28 showing warm moist air being drawn northward into eastern North Carolina with a 60-knot jet maximum approaching from the west.

Figure 4. Surface Analysis at 21Z showing cold front approaching from the west. Dewpoints were in the 70s over Eastern North Carolina ahead of the front.

Figure 5. The 12Z Newport/Morehead City Sounding showed conditions favorable for tornadic and large hail development on April 28.

Figure 6. Newport/Morehead City Doppler radar indicated two areas of intense rotation over Duplin County shortly after 3 pm April 28. Warsaw in Western Duplin County, northwest of Kenansville reported the first tornado touchdown of the day.

Figure 7. Newport/Morehead City Doppler radar indicated strong but broad rotation over northern Craven County around 430 pm April 28.

PRELIMINARY LOCAL STORM REPORT...SUMMARY

NATIONAL WEATHER SERVICE NEWPORT/MOREHEAD CITY NC

1211 PM EDT FRI APR 29 2011

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...

..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....

            ..REMARKS..

0252 PM     TSTM WND DMG     TEACHEY                 34.77N  78.01W

04/28/2011                   DUPLIN             NC   PUBLIC         

            SEVERAL TREES DOWN. TIME ESTIMATED BY RADAR.

0301 PM     TSTM WND DMG     5 SE MAGNOLIA           34.84N  77.99W

04/28/2011                   DUPLIN             NC   FIRE DEPT/RESCUE

            TURKEY BARNS AND OUTBUILDINGS DAMAGED. TREES DOWN. NEAR

            NC903 AND HALLS POND RD.

0310 PM     TORNADO          8 SE WARSAW             34.92N  77.99W

04/28/2011                   DUPLIN             NC   EMERGENCY MNGR 

            HOG FARM AND TREES SNAPPED IN A 150 TO 200 FT WIDE PATH

            APPROX 0.5 MILES LONG.

0343 PM     HAIL             1 N FARMVILLE           35.61N  77.59W

04/28/2011  E0.75 INCH       PITT               NC   TRAINED SPOTTER

0345 PM     HAIL             1 N PINK HILL           35.07N  77.74W

04/28/2011  E1.00 INCH       LENOIR             NC   PUBLIC         

0415 PM     TSTM WND DMG     3 SE WILLIAMSTON        35.82N  77.02W

04/28/2011                   MARTIN             NC   PUBLIC         

            TWO TREES DOWN ON A SHED ON BELLTOWN RD. TIME ESTIMATED

            BASED ON RADAR.

0435 PM     HAIL             3 NE VANCEBORO          35.34N  77.12W

04/28/2011  E2.75 INCH       CRAVEN             NC   EMERGENCY MNGR 

0435 PM     TSTM WND DMG     1 E FORT BARNWELL       35.27N  77.31W

04/28/2011                   CRAVEN             NC   EMERGENCY MNGR 

            TREES AND POWERLINES DOWN ON BELLTOWN ROAD.

0440 PM     HAIL             1 SE WILMAR             35.39N  77.14W

04/28/2011  E1.00 INCH       CRAVEN             NC   PUBLIC         

            RELAYED FROM 911 CENTER

0500 PM     TORNADO          PLYMOUTH                35.86N  76.75W

04/28/2011                   WASHINGTON         NC   PUBLIC         

            TREE DOWN ON GARAGE. TIME ESTIMATED BY RADAR.

0500 PM     TORNADO          PLYMOUTH                35.86N  76.75W

04/28/2011                   WASHINGTON         NC   PUBLIC         

            TREE DOWN ON PORCH ON MAIN ST.

0506 PM     TSTM WND DMG     PLYMOUTH                35.86N  76.75W

04/28/2011                   WASHINGTON         NC   PUBLIC         

            POWERLINES DOWN ON CHERRY ST

0530 PM     TSTM WND DMG     WENONA                  35.73N  76.63W

04/28/2011                   WASHINGTON         NC   LAW ENFORCEMENT

            TREES DOWN ON PIKE ROAD IN ADDITION TO 1 INCH HAIL

0620 PM     FUNNEL CLOUD     3 SSW COLUMBIA          35.88N  76.27W

04/28/2011                   TYRRELL            NC   LAW ENFORCEMENT

            REPORTED OVER NEWLANDS ROAD HEADING NE TOWARD COLUMBIA.

            RELAYED FROM 911 CENTER

&&

Sources –

Storm Prediction Center

GR2 Analyst Software