Saturday, September 3, 2011

Lessons Learned from 1943



Track of the Unnamed 1943 Hurricane/ Tropical Storm


This morning The Weather Channel reported that surge has flooded some areas near Chef Menteur, LA to a depth of around one foot. Prolonged easterly or southeasterly winds tend to pile up water in that area east of New Orleans.

This may be a similar setup in some ways to the 1943 surge event in SE Louisiana. An unnamed hurricane spun off the Texas Coast on Sept 17 and 18, then headed northeast towards Louisiana as a tropical storm on Sept 19 and 20. This setup provided prolonged onshore winds in portions of SE Louisiana. Around three feet of surge was reported in the Chef Menteur area, even though the storm track was hundreds of miles away.

Quote from Times Picayune, Sept 20, 1943:

Storm winds of 40 to 50 miles per hour which had been predicted for New Orleans as the hurricane hovered in the Gulf did not materialize Sunday, but rain throughout the day caused some streets to be flooded, though not as extensively as Saturday. From 6 p. m. Saturday to 1:13 p. m. Sunday, the weather bureau recorded .69 inches of rain here.

Lester Corley, district manager of the highway department, reported late Sunday afternoon that approximately 36 inches of water covered the New Orleans approaches to Pontchartrain bridge on Highway 11 and the road was closed to all traffic except heavy busses. Water, he said, partially covered Highway 90 between Highway 11 and Chef Menteur.

Unnamed 1943 Storm and Hurricane Juan (1985) May Provide Perspective on Lee's Surge Potential




The Unnamed 1943 hurricane spun off the Texas Coast, making a loop before heading NE into Louisiana.




Hurricane Juan (1985) made multiple loops as it approached the SW Louisiana Coast.


An unnamed 1943 Hurricane and Hurricane Juan (1985) may provide insight into TS Lee's storm surge potential. Although both of the previous storms were hurricanes, they spun off the Northern Gulf Coast, and were downgraded into tropical storms while still impacting the region.

The unnamed 1943 storm revealed one of the most interesting surge histories in the SURGEDAT dataset. Research originally looked for peak surge levels along the Texas Coast, however, the highest surge located for this storm occurred east of New Orleans, on Highway 11 near Chef Menteur. Prolonged onshore winds put around 3 feet of surge over Highway 11 in that storm, which translates to a surge level of approximately 6 feet. What is truly amazing is that this peak surge level occurred hundreds of miles from the storm's track.

Hurricane Juan generated a more typical storm surge, as the peak surge level was closer to the storm's track. Juan generated a peak surge of 8 feet at Cocodrie, LA.

These previous storms provide insight into the surge potential of TS Lee. The unnamed 1943 storm provides a great example of surge overwash occurring at considerable distance from the storm's track, especially in SE Louisiana, where prolonged east or southeast winds can pile up enough water to flood roadways.






Saturday, August 27, 2011

Surge Inundates Virginia; 8.5-foot surge reported in NC




Image Source: http://www.weather.com/weather/hurricanecentral/article/social-media-north-carolina-photos_2011-08-27

Quote from Source: A look at the flooding in Pamlico County. Early reports tell us the flooding is VERY bad here. http://twitpic.com/6c4x01 via @BrittanyyRice

Quote from The Weather Channel:
Coastal Concern: We've already seen a surge of 8.5 feet in parts of North Carolina. This doesn't bode well for the Hampton Roads and Norfolk metro areas during high tide. A storm surge of up to 5 to 9 feet above ground level is forecast in the Lower Chesapeake region, coinciding with a high tide. This could bring record flooding to parts of the cities of Norfolk and Chesapeake, Va.

Source: http://www.weather.com/weather/hurricanecentral/article/hurricane-irene-regional-impacts-mid-atlantic_2011-08-25

This evening NOAA Tides and Currents gauges are reporting surge levels between 4 and 5 feet in portions of North Carolina and Virginia. Surge levels are rising quickly in DE with surge levels approaching 3 feet at Lewes, Delaware. Keep in mind that storm surge is very localized and gauges often do not record the highest surge levels.

Heavier bands of rain are now over the Delmarva Peninsula, much of New Jersey and Southeast Pennsylvania. The NHC forecasts winds, and associated surge levels, to increase along the Delmarva Peninsula, Jersey Shore, Long Island, Long Island Sound, and southeastern New England tonight.

Although our coastal flooding research group primarily focuses on events that impact the Gulf of Mexico, some lessons that we learned along the Gulf Coast may apply to Irene's storm surge on the East Coast.

One lesson we learned is that sometimes surge does not show up where you may expect it, and then it does show up in the place or at the time you might not expect it. Take, for example, Tropical Storm Ida, which impacted the Gulf Coast in November, 2009. Ida's peak storm surge was actually located to the left of the storm track, which defies conventional wisdom about peak surge locations. Although Ida tracked just east of the Louisiana delta, and made landfall in Alabama, the peak surge from this event was actually a 6.53-foot surge at Bay Gardene, Louisiana.

A second lesson that Ida taught us had to do with the surge timing. In some locations, such as Shell Beach, LA, the storm surge peaked as Ida moved away from the area and winds shifted to the north. This pushed water that had built up towards the southern tip of Lake Borgne, generating peak surges for this event in some locations. It might seem impossible that a location could observe the peak surge during offshore winds, but that's what happened at Shell Beach during Ida.

As we watch Hurricane Irene march up the East Coast tonight, please take precaution and avoid areas vulnerable to storm surge. Remember that sometimes surge surprises us and if that cuts off an evacuation route or strands someone in a vehicle, the situation could quickly turn deadly. Stay tuned to the National Hurricane Center, the National Weather Service, and your local media outlets for the latest forecasts.




Friday, August 26, 2011

Surge Level Rising on NC Coast


Source: National Hurricane Center. Image downloaded approximately 1017PM EDT Aug 26, 2011.

Squalls have been pounding the NC Coast this evening, as winds have increased from the NE. This has helped push water towards the coast, raising surge levels.

Wrightsville Beach, NC is observing sustained winds around 36 MPH with gusts approaching 50 MPH from the NNE, according to NOAA Tides and Currents. Surge levels were around 2.8 feet around 10PM EDT, likely accompanied by large, destructive waves.

The National Hurricane Center forecasts increasing surge levels along the East Coast from NC north to New England this weekend. Stay tuned to the National Hurricane Center for the latest wind and surge forecasts.

Wednesday, August 24, 2011

Irene Pounds the Bahamas



Hurricane Irene pounds the Bahamas with 120MPH winds. Image source: http://www.ssd.noaa.gov/goes/flt/t2/avn-l.jpg

Hurricane Irene is strengthening as it crosses the Bahamas. The NHC reports that maximum sustained winds are now up to 120MPH, and it is possible that Irene will become a Category 4 hurricane, with winds exceeding 130MPH, according to the NHC.

SURGEDAT has identified 5 storm surge events in the Bahamas since 1880. Hurricane Andrew (1992) produced the highest surge in our database, a 4.88 m (16 ft) surge on Lower Bogue. Andrew was a Category 5 storm, packing winds as high as 172 MPH as it approached the Bahamas. (data source: http://www.weather.unisys.com/hurricane/atlantic/1992/index.html)

Irene is beginning to elevate sea levels along the East Coast of Florida and the Florida Keys. As of this afternoon, sea levels were about one-half foot above normal at Lake Worth Pier and over one foot above normal at times on Vaca Key, according to NOAA Tides and Currents.


Saturday, July 30, 2011

TS Don's Peak Storm Surge Was Generally 1-2 Feet



Image: NOAA Tides and Currents provided a webpage that provided quick access to water levels along the Gulf Coast as TS Don approached.

NOAA Tides and Currents provided a website to quickly access water levels along the Gulf Coast during Tropical Storm Don. Gauges along the Texas Coast reported elevated water levels as Don approached. The highest storm surge levels near Don's path ranged from 1-2 feet. Corpus Christi, TX reported a surge level of 1.83 feet at 9:06 PM CDT on 7/29/11, while the surge level at 8:48 PM reached 1.12 feet at Port O'Connor.

Friday, July 29, 2011

TS #1 (1960) and TS Arlene (1993) May Provide Helpful Context for TS Don's Surge



Infrared Satellite Image of TS Don (downloaded at 8:22AM CDT 7/29/11)



NHC forecast track for TS Don (downloaded at 8:22AM CDT 7/29/11)



Track of TS #1 (1960)



Track of TS Arlene (1993)


Image Source: Unisys Corporation (2011)

The National Hurricane Center's best track forecast for TS Don has shifted slightly south over the past 36 hours. This means that TS #1 (1960) and TS Arlene (1993) may provide the best historical context for TS Don's potential storm surge. Here is some information about those events:

Storm Name: TS #1
Storm Year: 1960
Landfall Location: S Texas
Maximum winds at landfall: ~ 46 MPH
Peak Surge: 3.5 feet
Peak Surge Location: Corpus Christi Bay

Storm Name: TS Arlene
Storm Year: 1993
Landfall Location: S Texas
Maximum winds at landfall: ~ 40 MPH
Peak Surge: 4 feet
Peak Surge Location: South and Central Texas Coast

Please stay tuned to your local media, local National Weather Service Forecast Office and the National Hurricane Center for official wind and storm surge forecasts.

Wednesday, July 27, 2011

Three tropical storms that generated surges in "Zone 2"







Images courtesy Unisys Corporation (2011)


Three tropical storms generated surges that reached their peak height in "Zone 2," which covers the Central Texas Coast. Here is a summary of these three events.

Name: Tropical Storm Abby
Year: 1964
Max winds at landfall: ~ 63 MPH
Peak Surge Height: 4 feet
Peak Surge Location: Matagorda to Freeport, Texas

Name: Tropical Storm Candy
Year: 1968
Max winds at landfall: ~ 69 MPH
Peak Surge Height: ~ 4.5 feet
Peak Surge Location: Palacios, Texas

Name: Tropical Storm Frances
Year: 1998
Max winds at landfall: ~ 63 MPH
Peak Surge Height: 8 feet
Peak Surge Location: Matagorda Locks, Texas


SURGEDAT identified 202 historical storm surge events along the U.S. Gulf Coast. Most tropical storms in this dataset generated surges in the 3-5 foot range. Tropical Storm Frances' 8-foot surge was very large for a tropical storm; this surge level is perhaps the highest generated by a tropical storm along the U.S. Gulf Coast.

These surge events may provide some general guidance regarding possible surge levels produced by Tropical Storm Don. Hopefully Don's surge will be closer to the typical storm surge levels generated by tropical storms in this region (3-5 feet), minimizing coastal damage.

Focus on Zone 2




The SCIPP program has recently divided the Gulf Coast into 10 storm surge zones for statistical analysis. Tropical Storm Don will likely impact "Zone 2," an area of the Central Texas Coast from near Port Lavaca to Freeport, Texas.

Surge research through the SCIPP program identified 14 surge events between 1900 and 2010 that peaked in Zone 2. The image above provides a snapshot of these surge events. The highest surge was 18.5 feet in Hurricane Carla (1961), the lowest was four feet in three separate events. Three of these events were generated by tropical storms: Tropical Storm Abby (1964), which produced a 4-foot surge between Matagorda and Freeport, TX; Tropical Storm Candy (1968), which produced a 4.5-foot surge in Palacios, TX; and Tropical Storm Frances (1998), which produced an 8-foot surge at Matagorda Locks.

These comparisons may help provide a very general guidance of surge potential from Tropical Storm Don, as Don should approach the Central Texas Coast as a tropical storm. Stay tuned to the National Hurricane Center, your local National Weather Service Forecast Office and local media outlets for the latest forecasts.

Tropical Storm Don forms in the Southern Gulf of Mexico





Tropical Storm Don formed in the Southern Gulf of Mexico this afternoon. The National Hurricane Center expects Don to the NW or WNW and approach the Central Texas Coast by Friday evening. They predict that Don will remain a tropical storm.

Stay tuned to Hurricane Hal's Storm Surge Blog for historical storm surge comparison to Don. I reference historical storm surge data on this blog to provide context for active surge events.

Tuesday, June 28, 2011

Tropical Storm Arlene kicks off 2011 Atlantic Hurricane Season



Tropical Storm Arlene formed in the Bay of Campeche this evening, kicking off the 2011 Atlantic Hurricane Season. The National Hurricane Center predicts that Arlene will remain a tropical storm as it drifts westward. Arlene should stay well south of the Texas/ Mexico border, however, onshore winds in South Texas could produce slightly elevated water levels and waves. Storm surge along the South Texas Coast should remain less than 3 feet above Mean Sea Level.

Stay tuned to Hurricane Hal's Storm Surge Blog for further updates.

Thursday, May 26, 2011

Cat 5 Super Typhoon Songda kicks off season in Western North Pacific


Source: http://www.wunderground.com/tropical/tracking/wp201104_sat.html?MR=1

Category-5 Super Typhoon Songda kicked off the typhoon season in the Western North Pacific this week. As of 0500 JST on Thursday, May 27, Songda was packing winds of 160 mph off the east coast of the Philippines. Songda is generating very high waves throughout much of East Asia, including the Philippines, Taiwan, and Southern Japan.

SURGEDAT has identified the maximum surge height and location of 66 surge events in East Asia between 1880 and 2010, however, lacks surge data for the Philippines. If you have information about the surge or wave heights for Songda or any other typhoons that have impacted the Philippines, please send observations, photos or video to Hurricane Hal at hneedh1@lsu.edu.

Stay safe and stay tuned to Hurricane Hal's Storm Surge Blog throughout this tropical season!

2011 Hurricane Season


Source: http://www.osdpd.noaa.gov/data/sst/anomaly/2011/anomw.5.5.2011.gif



The 2011 Atlantic Hurricane Season is nearly upon us! Hurricane season officially begins on June 1 and lasts until the end of November. This hurricane season should be a busy one as the National Oceanic and Atmospheric Administration (NOAA) predicts that the 2011 season will be more active than normal. NOAA is forecasting 12 to 18 named storms, 6 to 10 hurricanes, and 3 to 6 major hurricanes this season (National Oceanic and Atmospheric Administration, 2011).

The image posted to this blog depicts why this season may be more active than normal. This image indicates sea surface temperature anomalies, or how much warmer or colder sea surface temperatures are compared to normal, as of May 5, 2011. Much of the Atlantic basin, particularly the main development region for hurricane formation, is warmer than normal, which can lead to increased hurricane activity, as warm waters fuel hurricane development and growth. Much of the Equatorial Pacific Ocean, however, remains cooler than normal, setting up a La Nina pattern that generally reduces wind sheer in the Atlantic basin, providing a more conducive atmosphere for Atlantic hurricanes.

If the Atlantic hurricane season turns out to be an active one, stay tuned to the storm surge blog frequently. Although the focus of this blog is surge discussion for the U.S. Gulf Coast, look for a few surprises this year as the blog branches out to shed light on other high-profile surge events in other parts of the world too!

Reference:

National Oceanic and Atmospheric Administration, 2011: NOAA hurricane outlook indicates an above-normal Atlantic season. Publication available on the Web at: http://www.noaanews.noaa.gov/stories2011/20110519_atlantichurricaneoutlook.html.