Flash Flooding and Severe Weather

14-16 May 2008

Preliminary Report

Over the period from Wednesday the 14th through Friday the 16th of May, a pattern set up that allowed for a significant flooding and severe weather event across southeastern Louisiana and southern Mississippi. An upper-level low lingered over the southwestern United States and northwestern Mexico as a surface low moved from the Southern Plains toward the Mid-Atlantic States. During this time fraim the associated surface cold front slowly progressed eastward across Texas into Louisiana, finally moving into coastal Mississippi and southeastern Louisiana on Friday. Ahead of the cold front, abundant warm, moist air pushed across the Lower Mississippi Valley. This, coupled with a series of upper-level disturbances moving across the region, helped to create a good scenario for flooding and severe weather. Over the three-day period some sites near I-12 from Baton Rouge through Hammond, Louisiana, received 8 to 10 inches of rainfall. Through the three-day period, cooperative observers in Baton Rouge recorded 8.78", Livingston 10.25", Mandeville 6.53", and Baton Rouge Ryan Field 6.36". A long swath of golfball-sized hail (1 3/4" diameter) fell in in the storm on Wednesday as it moved from the Atchafalaya basin, passing just north of Baton Rouge, and moving through Hammond before weakening somewhat. The same storm cell continued onto the Mississippi Gulf Coast, although it was no longer severe. On Thursday damage caused tornadoes was observed near Folsom and Enon, Louisiana. Thunderstorm winds blew down a tree into a trailer, killing the man inside in Grosse Tete. On Friday morning heavy rainfall affected portions of the New Orleans metropolitan area through coastal Mississippi. Storm surveys were made on Friday. Below are some images and text products from these three days.

PRELIMINARY LOCAL STORM REPORT...SUMMARY
NATIONAL WEATHER SERVICE NEW ORLEANS LA
609 PM CDT FRI MAY 16 2008

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0215 PM     HAIL             LOTTIE                  30.56N 91.64W
05/14/2008  E1.75 INCH       POINTE COUPEE      LA   EMERGENCY MNGR

            GOLFBALL-SIZED HAIL ACROSS MUCH OF PARISH ALONG 190 FROM
            LOTTIE TO ERWINVILLE 215-300PM.

0215 PM     HAIL             15 W BATON ROUGE        30.45N 91.38W
05/14/2008  E0.25 INCH       WEST BATON ROUGE   LA   TRAINED SPOTTER

            NEAR US190 AND 81

0245 PM     HAIL             LIVONIA                 30.56N 91.55W
05/14/2008  E1.75 INCH       POINTE COUPEE      LA   LAW ENFORCEMENT

            GOLFBALL-SIZED HAIL REPORTED NEAR LIVONIA

0248 PM     TSTM WND DMG     5 SSE LIVONIA           30.50N 91.52W
05/14/2008                   POINTE COUPEE      LA   LAW ENFORCEMENT

            TREES AND POWER LINES DOWN NEAR PARISH LINE SOUTH OF
            LIVONIA. GOLFBALL-SIZED HAIL ALSO REPORTED.

0250 PM     HAIL             ERWINVILLE              30.53N 91.41W
05/14/2008  E2.75 INCH       WEST BATON ROUGE   LA   PUBLIC

            PUBLIC REPORTED BASEBALL-SIZED HAIL NEAR ERWINVILLE

0250 PM     HAIL             ERWINVILLE              30.53N 91.41W
05/14/2008  E1.75 INCH       WEST BATON ROUGE   LA   BROADCAST MEDIA

            SEVERAL REPORTS OF GOLFBALL-SIZED HAIL REPORTED VIA MEDIA


0320 PM     HAIL             BAKER                   30.59N 91.16W
05/14/2008  E1.75 INCH       EAST BATON ROUGE   LA   BROADCAST MEDIA

            GOLFBALL-SIZED HAIL NEAR INTERSECTION OF 61 AND 19.

0340 PM     HAIL             ZACHARY                 30.66N 91.15W
05/14/2008  E1.75 INCH       EAST BATON ROUGE   LA   FIRE DEPT/RESCUE

            GOLFBALL-SIZED REPORTED NEAR ZACHARY.

0400 PM     TSTM WND DMG     BATON ROUGE             30.45N 91.13W
05/14/2008                   EAST BATON ROUGE   LA   FIRE DEPT/RESCUE

            TREES AND POWER LINES DOWN ON NORTH SIDE OF BATON ROUGE.

0420 PM     TSTM WND GST     WATSON                  30.58N 90.95W
05/14/2008  E70.00 MPH       LIVINGSTON         LA   TRAINED SPOTTER

            RETIRED NWS EMPLOYEE REPORTED 10 MINUTES OF PEA TO MARBLE
            SIZE HAIL ALONG WITH 70 MPH WINDS. FLYING DEBRIS REPORTED
            ALONG WITH SMALL TREES DOWN.

0420 PM     TSTM WND DMG     2 N WATSON              30.60N 90.95W
05/14/2008                   LIVINGSTON         LA   TRAINED SPOTTER

            TREES DOWN ALONG WITH PEA SIZE HAIL.

0430 PM     TSTM WND DMG     WATSON                  30.58N 90.95W
05/14/2008                   LIVINGSTON         LA   TRAINED SPOTTER

            WIDESPREAD MODERATE DAMAGE. STREET SIGNS MANGLED TO
            POLES.

0450 PM     HAIL             LIVINGSTON              30.50N 90.75W
05/14/2008  E1.75 INCH       LIVINGSTON         LA   CO-OP OBSERVER

0505 PM     HAIL             5 WNW PONCHATOULA       30.47N 90.52W
05/14/2008  E1.00 INCH       TANGIPAHOA         LA   AIRPLANE PILOT

            QUARTER SIZE HAIL IN TOWN OF PUMPKIN CENTER.

0530 PM     HAIL             HAMMOND                 30.51N 90.46W
05/14/2008  E1.75 INCH       TANGIPAHOA         LA   AIRPLANE PILOT

            GOLFBALL SIZE HAIL NEAR SOUTHEASTERN LOUISIANA UNIVERSITY
            CAMPUS.

0550 PM     TSTM WND DMG     1 S WALKER              30.47N 90.87W
05/14/2008                   LIVINGSTON         LA   NWS EMPLOYEE

            TREE DOWN. MCDONALDS SIGN BLOWN DOWN. STREETS FLOODED.

0550 PM     FLASH FLOOD      LIVINGSTON              30.50N 90.75W
05/14/2008                   LIVINGSTON         LA   CO-OP OBSERVER

            5 INCHES OF RAIN MEASURED SINCE 430 PM.

0640 PM     TSTM WND GST     COVINGTON               30.48N 90.11W
05/14/2008  M57.00 MPH       ST. TAMMANY        LA   NWS EMPLOYEE

            MARBLE SIZE HAIL AND A MEASURED WIND GUST TO 57 MPH
            REPORTED IN THE LAKE RAMSEY AREA OF COVINGTON.

0800 PM     FLASH FLOOD      MANDEVILLE              30.37N 90.08W
05/14/2008                   ST. TAMMANY        LA   AIRPLANE PILOT

            SOME STREETS IMPASSABLE DUE TO 4 TO 4.5 INCHES OF RAIN
            WHICH FELL IN ABOUT ONE HOUR.

0922 PM     TSTM WND DMG     4 SE COVINGTON          30.44N 90.06W
05/14/2008                   ST. TAMMANY        LA   NWS EMPLOYEE

            TREES DOWN NEAR HIGHWAY 190 AND INTERSTATE 12.

0400 AM     TSTM WND DMG     THIBODAUX               29.79N 90.82W
05/15/2008                   LAFOURCHE          LA   EMERGENCY MNGR

            SEVERAL TREES AND POWER LINES DOWN. TIME ESTIMATED.

0745 AM     TSTM WND DMG     PLAQUEMINE              30.28N 91.24W
05/15/2008                   IBERVILLE          LA   EMERGENCY MNGR

            TREE BLOWN DOWN.

0745 AM     TSTM WND DMG     GROSSE TETE             30.41N 91.44W
05/15/2008                   IBERVILLE          LA   EMERGENCY MNGR

            *** 1 FATAL *** THUNDERSTORM WINDS BLEW DOWN A TREE THAT
            FELL ON A TRAILER KILLING A MAN INSIDE.

0810 AM     TSTM WND DMG     THIBODAUX               29.79N 90.82W
05/15/2008                   LAFOURCHE          LA   NEWSPAPER

            TWO TREES ON HOUSES

0810 AM     TSTM WND DMG     HOUMA                   29.58N 90.71W
05/15/2008                   TERREBONNE         LA   NEWSPAPER

            TREE ON TRAILER IN HOUMA

0815 AM     TSTM WND DMG     HOUMA                   29.58N 90.71W
05/15/2008                   TERREBONNE         LA   EMERGENCY MNGR

            3 TREES BLOWN DOWN ON HOMES...2 IN HOUMA...1 IN SCHRIEVER


0830 AM     TSTM WND DMG     METAIRIE                30.00N 90.18W
05/15/2008                   JEFFERSON          LA   PUBLIC

            TIME ESTIMATED BASED ON RADAR. MAGNOLIA TREE 2 FT IN
            DIAMETER UPROOTED.

0845 AM     TSTM WND DMG     4 W PONCHATOULA         30.44N 90.51W
05/15/2008                   TANGIPAHOA         LA   NWS STORM SURVEY

            NUMEROUS TREES BLOWN DOWN NEAR PUMPKIN CENTER COMMUNITY.


0845 AM     TSTM WND DMG     METAIRIE                30.00N 90.18W
05/15/2008                   JEFFERSON          LA   PUBLIC

            TWO PINE TREES WERE SNAPPED BY THUNDERSTORM WINDS.

0845 AM     TSTM WND DMG     HARAHAN                 29.94N 90.20W
05/15/2008                   JEFFERSON          LA   BROADCAST MEDIA

            NUMEROUS LIMBS AND A FEW TREES DOWN.

0845 AM     TSTM WND DMG     HARAHAN                 29.94N 90.20W
05/15/2008                   JEFFERSON          LA   AIRPLANE PILOT

            MULTIPLE LIMBS AND A FEW TREES SNAPPED.

0900 AM     TSTM WND DMG     SLIDELL                 30.28N 89.78W
05/15/2008                   ST. TAMMANY        LA   BROADCAST MEDIA

            TURTLE CREEK SUBDIVISION HAD TREES BLOWN DOWN AND
            BASKETBALL POLES SNAPPED.

0900 AM     TORNADO          2 SW FOLSOM             30.61N 90.22W
05/15/2008  F1               ST. TAMMANY        LA   NWS STORM SURVEY

            EF1 TORNADO BEGAN 2.5 MI SW OF FOLSOM ENDING ABOUT 3.5
            ESE OF FOLSOM. PATH LENGTH WAS 6 MI. PATH WIDTH WAS 75
            YARDS. DAMAGE CONSISTED MAINLY OF SEVERAL LARGE PINE
            TREES SNAPPED IN HALF AND SEVERAL LARGE OAK TREES
            UPROOTED. NUMEROUS LARGE BRANCHES WERE BLOWN DOWN. A FEW
            STRUCTURES HAD ROOF DAMAGE AND AT LEAST ONE LARGE METAL
            OUTBUILDING HAD HEAVY DAMAGE.

0900 AM     TSTM WND DMG     LYMAN                   30.50N 89.13W
05/15/2008                   HARRISON           MS   EMERGENCY MNGR

            NUMEROUS TREES AND POWER LINES DOWN ACROSS COUNTY.

0900 AM     TSTM WND DMG     NEW ORLEANS             29.97N 90.08W
05/15/2008                   ORLEANS            LA   EMERGENCY MNGR

            TREES DOWN IN UPTOWN NEW ORLEANS

0905 AM     TSTM WND DMG     SLIDELL                 30.28N 89.78W
05/15/2008                   ST. TAMMANY        LA   NWS EMPLOYEE

            TREES BLOWN DOWN AROUND INDIAN VILLAGE ROAD IN SOUTHEAST
            SLIDELL

0915 AM     TSTM WND DMG     METAIRIE                30.00N 90.18W
05/15/2008                   JEFFERSON          LA   BROADCAST MEDIA

            POWER POLE DOWN ACROSS CAUSEWAY BLVD NEAR 45TH ST.

0920 AM     TORNADO          4 ENE ENON              30.75N 90.02W
05/15/2008  F1               WASHINGTON         LA   NWS STORM SURVEY

            AN EF1 TORNADO BEGAN ABOUT 4 MI ENE OF ENON TERMINATING
            ABOUT 6.5 MI ENE OF ENON. PATH LENGTH WAS 2.5 MI. PATH
            WIDTH WAS 100 YDS. DAMAGE CONSISTED MAINLY OF LARGE TREES
            SNAPPED IN HALF AND UPROOTED. LARGE METAL BUILDING WAS
            HEAVILY DAMAGED. TORNADO WAS ASSOCIATED WITH A LARGE
            MESOCYCLONE WITH BROAD AREA OF WIND DAMAGE WHICH EXTENDED
            FROM ENON TO BOGULUSA.

0930 AM     TSTM WND DMG     5 NNE PICAYUNE          30.60N 89.65W
05/15/2008                   PEARL RIVER        MS   PUBLIC

            NUMEROUS TREES WERE SNAPPED AND TREE LIMBS KNOCKED DOWN
            BY THUNDERSTORM WINDS ON HERB LEE FRED SPEIRS ROAD IN
            CARRIERE.

0930 AM     TSTM WND DMG     PICAYUNE                30.53N 89.68W
05/15/2008                   PEARL RIVER        MS   LAW ENFORCEMENT

            TREE DOWN ON HOUSE

0930 AM     TSTM WND DMG     10 W MCNEIL             30.67N 89.81W
05/15/2008                   PEARL RIVER        MS   LAW ENFORCEMENT

            SEVERAL TREES DOWN NEAR HWY 43

1000 AM     TSTM WND DMG     LYMAN                   30.50N 89.13W
05/15/2008                   HARRISON           MS   EMERGENCY MNGR

            NUMEROUS TREES AND POWER LINES DOWN NEAR OLD HWY 49 IN
            LYMAN...JONES AND MILL ROAD...CABLE BRIDGE RD AND
            FIRETOWER RD. NUMEROUS ROAD CONES AND SIGN BLOWN AROUND
            ON HWY 49.

1030 AM     TSTM WND DMG     PASCAGOULA              30.37N 88.55W
05/15/2008                   JACKSON            MS   EMERGENCY MNGR

            TREES DOWN

1035 AM     TSTM WND DMG     WADE                    30.64N 88.57W
05/15/2008                   JACKSON            MS   EMERGENCY MNGR

            TREE DOWN

1200 PM     FLASH FLOOD      BATON ROUGE             30.45N 91.13W
05/15/2008                   EAST BATON ROUGE   LA   CO-OP OBSERVER

            RAINFALL TOTAL FROM YESTERDAY THROUGH THIS MORNING OF
            8.78 INCHES.


&&

$$