Hurricane Irene August 26-27, 2011

 

Event Overview 

Hurricane Irene was a large and powerful Atlantic hurricane that left extensive flood and wind damage along its path through the Caribbean, the United States East Coast and as far north as Canada (Figure 1). Irene made landfall near Cape Lookout, North Carolina at around 7:30 AM EDT on August 27, 2011 as a strong category 1 storm (Figure 2). Irene caused 5 deaths in North Carolina. On the evening of August 26, well ahead of landfall, Hurricane Irene also spawned several tornadoes. One EF-2 tornado near Columbia in Tyrrell County demolished at least 4 homes and overturned cars.

Precipitation totals associated with Irene were particularly high (Figure 3) with totals ranging from around 5 inches over the Northern Outer Banks, to around 15 inches in Beaufort County. Bunyan in Beaufort County reported 15.66 inches. Doppler Radar estimated totals of over 17 inches in portions of Beaufort, Craven and Pamlico Counties (Figure 4). Extensive storm surge and wind damage also occurred with Irene. The peak wind gust recorded was 115 mph at the Cedar Island Ferry Terminal in Carteret County as the eye was moving ashore (Figure 5). Trees were down throughout eastern North Carolina and thousands were left without electricity. Ocean and Sound overwash created numerous breaches of Highway 12 along the Outer Banks.

Figure 1. Track of Hurricane Irene, August 20 through 29, 2011. (Source: National Hurricane Center)

 

Figure 2. Eye of Hurricane Irene making landfall near Cape Lookout, NC at 749 AM EDT, August 27, 2011

 

 

Figure 3. Rainfall Totals from Hurricane Irene, August 26-27, 2011

 

Figure 4. Newport/Morehead City Doppler Radar Estimated Rainfall for Hurricane Irene. Note the large white area of over 17 inches over Beaufort, Craven and Pamlico Counties.

 

Figure 5. Peak Wind Gusts from Hurricane Irene, August 27, 2011.The peak wind gust recorded was 115 mph at the Cedar Island Ferry Terminal in Carteret County.

Evolution and Impacts 

Hurricane Irene evolved from a tropical wave that exited the African coast on August 15, 2011. With a favorable environment ahead of the wave, a Tropical Depression formed on August 20 as the wave approached the Lesser Antilles. By 23Z on August 20, the depression was upgraded to Tropical Storm Irene. On August 21, the surface center reformed closer to the deepest convection, as an anticyclone aloft provided supportive outflow over the cyclone. With the improved structure, as well as light wind shear and high sea surface temperatures, Irene was forecast to strengthen to near hurricane force prior to landfall in Hispaniola. Over the subsequent day (August 22), while passing near the island of Saint Croix in the U.S. Virgin Islands, Irene moved toward Puerto Rico, more northward than initially expected, where it underwent a considerable increase in strength and organization. Hours later, Irene moved ashore, approaching from the southeast at landfall near Punta Santiago, Puerto Rico, with estimated sustained winds of 70 mph. Despite the storm's interaction with land, radar imagery showed a ragged eye-like feature, and Doppler radar data indicated wind speeds in excess of hurricane force. Just after its initial landfall, Irene was accordingly upgraded to a Category 1 hurricane, the first of the 2011 Atlantic hurricane season.

After briefly weakening on August 23, Irene began to develop a distinct eye encircled by an area of deepening convection the next morning. Moving erratically through the southeast Bahamas over very warm waters, Irene quickly expanded as its outflow aloft became very well established. The hurricane intensified into a Category 3 major hurricane as it recurved toward the northwest along a weakness in the subtropical ridge. Irene would gradually weaken to a strong Category 1 storm as it approached the North Carolina coast as dry air wrapped into the hurricane.

Tropical-storm force winds began to affect the Outer Banks and Crystal Coast during the early evening hours of August 26. Additionally, Irene spawned several tornadoes during the late evening hours of August 26, producing significant damage in Tyrrell, Washington and Beaufort Counties. Figure 6 shows the strong rotational couplet associated with an EF-1 tornado near Creswell, North Carolina around 1055 pm August 26.

Figure 6. Strong Rotational Couplet in the Doppler velocities from Creswell, NC around 1055 pm August 26. This couplet produced an EF-1 tornado.

 

Irene made landfall between 7:30 and 8 AM EDT Saturday August 27 near Cape Lookout, North Carolina. As the eye wall moved ashore, wind gusts to 115 mph were observed at the Cedar Island Ferry Terminal. The lowest pressure observed with the landfall of Irene was at Beaufort (Figure 7) with 28.11 inches of mercury or around 951 millibars at 8:56 AM. Strong winds and driving rains pounded most of Eastern North Carolina into the mid-afternoon hours on Saturday. As the eye moved inland, strong westerly winds on the backside of the storm gusted to near 100 mph at Atlantic Beach around 10:30 AM. Torrential rainfall amounts in excess of 10 inches were widespread. Storm surge levels of over 10 feet were observed at Ocracoke and several breaches of Highway 12 were noted all along the Outer Banks. A total of 5 people were killed in North Carolina as the result of Irene.

Figure 7. Barometric Pressure Graph from Beaufort, NC August 26-27, 2011. (Courtesy: National Ocean Service)

 

 

PUBLIC INFORMATION STATEMENT

NATIONAL WEATHER SERVICE NEWPORT/MOREHEAD CITY NC

550 PM EDT SUN AUG 28 2011

 

...PUBLIC INFORMATION STATEMENT...

 

THE FOLLOWING ARE UNOFFICIAL OBSERVATIONS TAKEN DURING HURRICANE IRENE.

APPRECIATION IS EXTENDED TO HIGHWAY DEPARTMENTS...COOPERATIVE

OBSERVERS...SKYWARN SPOTTERS...COCORAHS OBSERVERS AND MEDIA FOR

THESE REPORTS. THIS SUMMARY IS ALSO AVAILABLE ON OUR HOME PAGE AT

WEATHER.GOV/NEWPORT/

 

***********************PEAK WIND GUST***********************

 

LOCATION             MAX WIND     TIME/DATE   COMMENTS              

                         GUST            OF

                          MPH   MEASUREMENT     

                            

NORTH CAROLINA

 

...BEAUFORT COUNTY...

   WASHINGTON              45   435 AM  8/27  KOCW-DOWN AT 455 AM (8/27)

   AURORA                  90   845 AM  8/27  PCS PHOSPHATE

 

...CARTERET COUNTY...

   CEDAR ISLAND           115   750 AM  8/27  CEDAR ISLAND FERRY TERM                 

   BEAUFORT                70  1003 AM  8/27  KMRH-DOWN AT 1003 AM(8/27)

   FORT MACON              92  1110 AM  8/27  WEATHERFLOW

   CAPE LOOKOUT            78   400 AM  8/27  WEATHERFLOW

   MOREHEAD CITY           78   329 AM  8/27  MHC POLICE DEPT

   MOREHEAD CITY           70  1130 AM  8/27  WEATHERFLOW-DOWN AT 1103 AM(8/27)         

   NEWPORT                 64   849 AM  8/27  NWS NEWPORT

   STACY                   93   408 AM  8/27  TRAINED SPOTTER

   BEAUFORT                77   641 AM  8/27  TRAINED SPOTTER

   NEWPORT                 74  1015 AM  8/27  TRAINED SPOTTER

   BEAUFORT                76  1101 AM  8/27  TRAINED SPOTTER   

   ATLANTIC BEACH         101  1035 AM  8/27  TRAINED SPOTTER  

 

...CRAVEN COUNTY...

   CHERRY POINT            75  1154 PM  8/27  KNKT                 

   NEUSE RIVER             59   125 AM  8/27  WEATHERFLOW-DOWN AT 135 AM (8/27)

   NEW BERN                74   751 AM  8/27  KEWN-DOWN AT 849 AM (8/27)                 

 

...DARE COUNTY...

   MANTEO                  74   755 AM  8/27  KMQI                 

   FRISCO WOODS            76   610 AM  8/27  WEATHERFLOW-DOWN AT 1010 PM(8/28)

   HATTERAS HIGH           68   710 AM  8/27  WEATHERFLOW-DOWN AT 1020 PM(8/27)

   HATTERAS                88   851 AM  8/27  KHSE                 

   BUXTON                  79   930 AM  8/27  WEATHERFLOW-DOWN AT 920 PM (8/27)

   MANTEO CSWY             69  1118 AM  8/27  WEATHERFLOW

   ALLIGATOR BRIDGE        66   847 AM  8/27  WEATHERFLOW

   OREGON INLET            78   856 AM  8/27  WEATHERFLOW

   AVON (OCEAN SIDE)       77   725 AM  8/27  WEATHERFLOW-DOWN AT 903 AM (8/26)

   AVON (SOUND SIDE)       67   635 AM  8/27  WEATHERFLOW-DOWN AT 836 AM (8/27)

   WAVES                   57   713 AM  8/27  WEATHERFLOW

   SALVO                   69   755 AM  8/27  WEATHERFLOW

   BUXTON                  79   600 AM  8/27  WEATHERFLOW          

   PAMLICO SOUND           58  1050 AM  8/27  WEATHERFLOW-DOWN AT 1130 PM(8/26)

   REAL SLICK              77  1020 AM  8/27  WEATHERFLOW-DOWN AT 654 PM (8/27)

   WAVES                   63   725 AM  8/27  WEATHERFLOW-DOWN AT 921 AM (8/27)

   OREGON INLET            77   210 PM  8/27  WEATHERFLOW-DOWN AT 618 PM (8/27)

   MANTEO                  74   435 PM  8/27  WEATHERFLOW-DOWN AT 537 PM (8/27)

   MANTEO CSWY             68  1015 AM  8/27  WEATHERFLOW-DOWN AT 537 PM (8/27)

   JOCKEYS RIDGE           69   400 PM  8/27  WEATHERFLOW-DOWN AT 646 PM (8/27)

   PEA ISLAND              83   950 AM  8/27  KPEI

   DUCK                    85  1036 AM  8/27  DUCK COE PIER

  

...DUPLIN COUNTY...

   2 N KENANSVILLE         58   915 AM  8/27  KDPL                  

 

...HYDE COUNTY...

   OCRACOKE                69   439 AM  8/27  WEATHERFLOW-DOWN AT 616 AM (8/27)

 

...JONES COUNTY...

   WYSE FORKS              70  1131 AM  8/27  TRAINED SPOTTER

 

...ONSLOW COUNTY...

   JACKSONVILLE            50   355 AM  8/27  KOAJ-DOWN AT 415 AM (8/27)                  

   NEW RIVER               61   356 AM  8/27  KNCA-DOWN AT 429 AM (8/27)                 

   JACKSONVILLE            94   615 AM  8/27  TRAINED SPOTTER

 

...PITT COUNTY...

   GREENVILLE              64   835 AM  8/27  KPGV   

   GREENVILLE              73   700 AM  8/27  PITT EOC

 

...TYRRELL COUNTY...  

   ALLIGATOR BRIDGE        71  1050 AM  8/27  WEATHERFLOW-DOWN AT 328 PM (8/27)

 

...NDBC BUOY...

   DUCK PIER               79   512 PM  8/27  DUKN7

   OREGON INLET MARINA     80   400 PM  8/27 

   HATTERAS                79   536 AM  8/27

   CAPE LOOKOUT            78   400 AM  8/27  CLKN7

   BEAUFORT                67   612 AM  8/27  BFTN7

   41036                   69   820 AM  8/27 

***********************BAROMETRIC PRESSURE***********************

 

LOCATION     LOWEST PRESSURE    DATE/       COMMENTS

                      INCHES    TIME

 

HATTERAS       28.65           8/27  135 PM    KHSE

BEAUFORT       28.11           8/27  856 AM    KMRH

CHERRY POINT   28.18           8/27  854 AM    KNKT

GREENVILLE     28.84           8/27 1235 PM    KPGV

 

...NDBC BUOYS...

 

41036          28.25           8/27  620 AM  

44014          29.20           8/27 1150 AM

CLKN7          28.15           8/27  800 AM

ORIN7          28.80           8/27 1218 PM

 

 

*******************STORM TOTAL RAINFALL REPORTS***********************

 

LOCATION            TOTAL PRECIP      COMMENTS

 

...BEAUFORT...

   BUNYAN             15.66           RAWS - BNYN7

   WASHINGTON         13.11           HYDRO - TRAN7

 

...CARTERET COUNTY...

   CROATAN FOREST     11.13           RAWS - NPTN7

   NEWPORT            10.41           WFO MHX  

   NEWPORT             9.41           NEWPORT 0.2 SW                

   MOREHEAD CITY       8.11           MOREHEAD CITY 6.0 WNW

   NEWPORT             7.81           NEWPORT 2.0 WSW 

   BEAUFORT            7.00           BEAUFORT 5.3 N   

   CEDAR ISLAND        6.68           RAWS - TS788

   MOREHEAD CITY       6.65           MOREHEAD CITY 0.6 NW

   BEAUFORT            6.31           ASOS - KMRH

 

...CRAVEN COUNTY...

   NEW BERN           14.79           NEW BERN 1.3 NNE   

   NEW BERN           12.86           RAWS - NBRN7

   HAVELOCK           10.70           HAVELOCK 1.4 SW   

   NEW BERN            7.79           ASOS - KEWN

   TRENT WOODS         5.94           TRENT WOODS 1.3 SSE

   PERRYTOWN           5.04           COOP - PYTN7 (8/27)

 

...DARE COUNTY...

   DARE BOMB RANGE     7.57           RAWS - STCN7

   HATTERAS            6.77           ASOS - KHSE

   KILL DEVIL HILLS    2.43           KILL DEVIL HILLS 0.9 WNW

 

...DUPLIN COUNTY...

   BEAULAVILLE         9.61           BEAULAVILLE 0.5 NE   

   MOUNT OLIVE         5.68           COOP - MTON7

   MOUNT OLIVE         4.66           MOUNT OLIVE 2.4 SW

 

...HYDE COUNTY...

   FAIRFIELD           7.61           RAWS - TS161

   OCRACOKE            2.72           COOP - OCRN7 (8/27)

 

...LENOIR COUNTY...

   KINSTON             9.53           KINSTON 3.7 WNW

 

...MARTIN COUNTY...

   WILLIAMSTON        14.27           WILLIAMSTON 0.9 SSW

 

...ONSLOW COUNTY...

   JACKSONVILLE       11.70           JACKSONVILLE 5.5 WSW

   SWANSBORO           9.76           SWANSBORO 3.3 NW              

   CAMP LEJUENE        9.57           HYDRO - CLJN7

   HUBERT              9.36           HUBERT 4.3 SE

   HUBERT              9.12           HUBERT 4.9 SE

   RICHLANDS           8.87           RICHLANDS 2.8 SSE

   JACKSONVILLE        8.36           JACKSONVILLE 1.7 W

   HOFMANN FOREST      7.95           RAWS - HFMN7

   JACKSONVILLE        6.80           COOP - JEON7

 

...PAMLICO COUNTY...

   BAYBORO            15.74           COOP - BAYN7

 

...PITT COUNTY...

   GRIFTON            12.69           HYDRO - GRTN7

   GREENVILLE         12.32           GREENVILLE 7.1 SSE

   GREENVILLE         11.64           COOP - GREN7

   GREENVILLE         10.57           GREENVILLE 8.2 SSE

   GREENVILLE         10.50           HYDRO - PGVN7

   GREENVILLE         10.25           GREENVILLE 1.1 S

   WINTERVILLE         9.74           WINTERVILLE 3.5 W

   GREENVILLE          8.69           GREENVILLE 1.4 SE

   GREENVILLE          7.23           AWOS - KPGV

 

...WASHINGTON COUNTY...

   POCOSIN LAKES      11.20           HYDRO - POCN7

 

 

$$

Sources –

National Hurricane Center

National Ocean Service

WITN TV

WCTI TV

Wikipedia

GR2 Analyst Software

Damage Pictures from Eastern North Carolina 
Photos courtesy of: Storm Survey Team

 

 

 

 

 

 

 

 

Case Study Team:
MHX Case Study Team