Tornado Warning 44, NWS New Orleans, LA

000 
WWUS54 KLIX 171755
SVSLIX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE NEW ORLEANS LA
1255 PM CDT SUN MAY 17 2009

LAC075-171804-
/O.EXP.KLIX.TO.W.0044.000000T0000Z-090517T1800Z/
PLAQUEMINES LA-
1255 PM CDT SUN MAY 17 2009

...THE TORNADO WARNING FOR NORTHWESTERN PLAQUEMINES PARISH HAS
EXPIRED...

THE STORM THAT PROMPTED THE TORNADO WARNING IN THE RURAL MARSHES OF 
UPPER PLAQUEMINES PARISH HAS WEAKENED. OTHER STRONG STORMS CONTINUE 
TO MOVE INTO THE NEAR COASTAL WATERS NEAR BLACK BAY. WATERSPOUTS MAY 
OCCUR UNDER THESE STORMS THROUGH 130 PM. 

LAT...LON 2962 8988 2976 8998 2983 8988 2980 8987
      2980 8982 2979 8979 2977 8978 2977 8975
      2974 8970
TIME...MOT...LOC 1754Z 320DEG 6KT 2977 8989

$$


24/RR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEW ORLEANS LA
755 AM CDT SUN MAY 17 2009

.UPDATE...
...SOUNDING DISCUSSION...

EXTREMELY MOIST SOUNDING THIS MORNING...STILL UNSTABLE BUT NOT AS
MUCH INSTABILITY AS THE PAST FEW MORNING SOUNDINGS...PRECIPITABLE
WATER VALUE OF 1.75 INCHES AND A LIFTED INDEX VALUE OF -3.1. A
NORTHERLY WIND IS PRESENT AT THE SURFACE AND WESTERLY WINDS
THROUGHOUT THE ATMOSPHERE...OVERALL THE WINDS ARE VERY LIGHT AND
ANY CONVECTION THAT DEVELOPS WILL BE SLOW MOVING...0 TO 6 KM STORM
MOTION IS FROM THE WEST AT 4 KNOTS.

&&

.PREV DISCUSSION... /ISSUED 347 AM CDT SUN MAY 17 2009/

SYNOPSIS...
WIND FIELDS INDICATE THAT SURFACE FRONTAL BOUNDARY HAS EXITED THE
COAST. DRIER AIR...HOWEVER...STILL RESIDES NORTH OF INTERSTATE 20
OVER NORTHERN LOUISIANA AND CENTRAL MISSISSIPPI. A RELATIVE
MINIMUM OF PRECIPITATION CURRENTLY OVER THE FORECAST AREA...WITH
SCATTERED SHOWERS OVER THE COASTAL WATERS...AND MORE EXTENSIVE
AREA OF PRECIPITATION NORTH OF A MERIDIAN TO NATCHEZ LINE.
TEMPERATURES GENERALLY IN THE UPPER 60S AND LOWER 70S WITH DEW
POINTS BETWEEN 65 AND 70 UNDER LIGHT NORTH WINDS.

SHORT TERM...
BOUNDARY WILL CONTINUE TO SHIFT SOUTHWARD...GETTING A LITTLE
BETTER PUSH THIS AFTERNOON AND EVENING AS NORTHERN STREAM IMPULSE
MOVES INTO THE EASTERN TROF. ABUNDANT CLOUD COVER WILL LIMIT
SURFACE HEATING TODAY...WITH THE RESULT BEING WEAKER CONVECTION.
WILL CONTINUE THE LIKELY POPS...BUT THUNDER MAY NOT BE AS COMMON
AS ORIGINALLY EXPECTED. PRECIPITATION WILL GRADUALLY DEPART THE
AREA TONIGHT AS DRIER AIR MOVES IN. UPSTREAM AIRMASS WILL BRING
DEW POINTS IN THE 40S AND 50S TO THE AREA FOR THE FIRST TIME IN A
WHILE. NO PRECIPITATION EXPECTED OVER LAND AREAS THROUGH TUESDAY.

MOST NOTABLE EFFECT OF THIS SYSTEM WILL BE THE COOLER AND DRIER
AIR MOVING IN. TODAYS TEMPERATURE FORECAST HAS A RATHER HIGH BUST
POTENTIAL...AS GUIDANCE HIGH TEMPS ARE ABOUT 5 DEGREES WARMER THAN
CURRENT TEMPERATURES OVER NORTHERN HALF OF THE AREA. A FEW HOURS
OF FILTERED SUNSHINE BEFORE THE DRIER AIR ARRIVES COULD ALLOW
TEMPERATURES TO JUMP WELL ABOVE FORECAST HIGHS...BUT EARLY MORNING
PRECIPITATION COULD ALSO FLATTEN TEMPERATURES FOR THE REMAINDER OF
THE DAY. WILL GO ABOVE GUIDANCE NORTH OF INTERSTATE 12...AND CLOSE
TO MAV GUIDANCE TO THE SOUTH TODAY. TEMPERATURES FOR TONIGHT
THROUGH TUESDAY WILL GENERALLY BE 5-10 DEGREES BELOW NORMAL. WITH
NORTH TO NORTHEAST WINDS EXPECTED...IT IS ENTIRELY POSSIBLE THAT
THE GULFPORT AREA COULD ACTUALLY END UP WARMER THAN ONE MIGHT
EXPECT MONDAY AND TUESDAY AS THERE SHOULD BE NO MARINE
MODIFICATION THERE. 35

LONG TERM...
COULD BE AN INTERESTING END OF THE WEEK AND WEEKEND. GFS AND ECMWF
ARE COMING INTO AGREEMENT ON A SOLUTION WITH THE UPPER LOW
EXPECTED TO FORM OVER THE SOUTHEAST GULF OF MEXICO. GENERAL TRACK
WOULD BE FROM NEAR TAMPA AREA ON WEDNESDAY TO THE MOBILE-PENSACOLA
AREA FRIDAY...THEN OVER CENTRAL MISSISSIPPI AND ALABAMA FOR THE
WEEKEND. ECMWF IS SLIGHTLY SLOWER AND STRONGER...BUT SAME GENERAL
TRACK. THIS TRACK WOULD HAVE OUR AREA ON THE DRIER SIDE OF THE
LOW TRACK.

WE WILL BEGIN TO SEE CLOUDS INCREASE WEDNESDAY WITH CHANCES FOR
PRECIPITATION RETURNING THURSDAY. FOR NOW...WILL KEEP 12 HOUR POPS
IN THE CHANCE RANGE FOR THURSDAY AND BEYOND UNTIL TIMING AND STRENGTH
IS A LITTLE BETTER DEFINED. MAIN CONCERNS WILL BE POTENTIAL FOR
VERY HEAVY RAIN...ESPECIALLY AROUND FRIDAY AND SATURDAY.

WILL GO GENERALLY CLOSE TO THE MEX GUIDANCE FOR THE EXTENDED PERIOD.
GFS SOLUTION IS DRIVING THE FORECAST FOR THE END OF THE WEEK. 35

AVIATION...
..06Z TAF ISSUANCE...
A CHANCE OF SCATTERED SHRA/ISOLATED TSRA IS EXPECTED IN THE
MORNING. THE COLD FRONT WILL PASS THROUGH THE AREA THIS MORNING
WITH MVFR TO POSSIBLE IFR CIGS DEVELOPING THIS MORNING THEN
LIFTING SLOWLY THIS AFTERNOON AND EVENING. MODERATE NORTH WINDS
ARE EXPECTED AT ALL FOUR TAF SITES TONIGHT. AT MSY...SIGNIFICANT
COLD AIR ADVECTION ACROSS LAKE WATER TEMPERATURES ARE IN THE LOWER
80S WILL PRODUCE BRISK WINDS AT MSY LATER THIS AFTERNOON THROUGH
12Z MONDAY. 18

MARINE...
LOWER PRESSURE AREA ACROSS THE SOUTH GULF AND HIGH OVER THE
MISSISSIPPI HAVE PRODUCED NORTHEAST WINDS ACROSS THE COASTAL WATERS
AHEAD OF THE FRONTAL BOUNDARY EARLY THIS MORNING. NORTHEAST WINDS
WILL INCREASE INTO SMALL CRAFT ADVISORY CRITERIA FOR TIDAL LAKES AND
COASTAL WATERS TONIGHT AND POSSIBLY CONTINUING THROUGH TUESDAY. AN
UPPER LEVEL LOW PRESSURE SYSTEM STILL LOOKS TO MOVE INTO THE GULF
LATER IN THE WEEK AND MAY TRANSLATE DOWN TO THE SURFACE AS A LOW.
UNCERTAINTY STILL EXISTS WITH THIS SYSTEM BUT WILL PROBABLY BE THE
MAIN INFLUENCE ON THE MARINE FORECAST IN THE UPCOMING WEEK. 18

&&

.PRELIMINARY POINT TEMPS/POPS...
MCB  72  52  77  50 /  60  10   0   0
BTR  76  54  78  52 /  60  10   0   0
MSY  80  60  76  62 /  60  30   0   0
GPT  79  57  77  54 /  60  30   0   0

&&

.LIX WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
GM...SMALL CRAFT ADVISORY FROM 7 PM THIS EVENING TO 7 AM CDT
     WEDNESDAY FOR GMZ550-555-570-575.

MS...NONE.
GM...SMALL CRAFT ADVISORY FROM 7 PM THIS EVENING TO 7 AM CDT
     WEDNESDAY FOR GMZ555-570-575.

&&

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE NEW ORLEANS LA
1118 AM CDT SUN MAY 17 2009

GMZ530-550-555-570-575-LAZ034>040-046>050-056>070-MSZ068>071-077-
080>082-181630-
LAKE PONTCHARTRAIN AND LAKE MAUREPAS-
COASTAL WATERS FROM THE SOUTHWEST PASS OF THE MISSISSIPPI RIVER
TO LOWER ATCHAFALAYA RIVER LA OUT 20 NM-
COASTAL WATERS FROM PASCAGOULA MS TO THE SOUTHWEST PASS OF THE
MISSISSIPPI RIVER OUT 20 NM-
COASTAL WATERS FROM THE SOUTHWEST PASS OF THE MISSISSIPPI RIVER
TO LOWER ATCHAFALAYA RIVER LA FROM 20 TO 60 NM-
COASTAL WATERS FROM PASCAGOULA MS TO THE SOUTHWEST PASS OF THE
MISSISSIPPI RIVER FROM 20 TO 60 NM-POINTE COUPEE-WEST FELICIANA-
EAST FELICIANA-ST. HELENA-TANGIPAHOA-WASHINGTON-ST. TAMMANY-
IBERVILLE-WEST BATON ROUGE-EAST BATON ROUGE-ASCENSION-LIVINGSTON-
ASSUMPTION-ST. JAMES-ST. JOHN THE BAPTIST-UPPER LAFOURCHE-
ST. CHARLES-UPPER JEFFERSON-ORLEANS-UPPER PLAQUEMINES-
UPPER ST. BERNARD-UPPER TERREBONNE-LOWER TERREBONNE-
LOWER LAFOURCHE-LOWER JEFFERSON-LOWER PLAQUEMINES-
LOWER ST. BERNARD-WILKINSON-AMITE-PIKE-WALTHALL-PEARL RIVER-
HANCOCK-HARRISON-JACKSON-
1118 AM CDT SUN MAY 17 2009

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF COASTAL WATERS
OF SOUTHEAST LOUISIANA AND SOUTH MISSISSIPPI...SOUTHEAST
LOUISIANA AND SOUTHERN MISSISSIPPI.

.DAY ONE...THIS AFTERNOON AND TONIGHT
THUNDERSTORMS...THERE WILL BE A CHANCE OF THUNDERSTORMS ACROSS THE
AREA THROUGH THIS EVENING AS A COLD FRONT CONTINUES TO MOVE
THROUGH THE REGION. WIDESPREAD SEVERE WEATHER IS NOT ANTICIPATED.
HOWEVER...A FEW OF THE STRONGER STORMS WILL BE CAPABLE OF
PRODUCING STRONG WIND GUSTS AND HAIL.

MARINE HAZARDS...THUNDERSTORMS OVER THE GULF WATERS WILL BE
CAPABLE OF PRODUCING ISOLATED WATERSPOUTS THROUGH THIS EVENING.
ADDITIONALLY...STRONG NORTH TO NORTHEAST WINDS BEHIND THE COLD
FRONT WILL RESULT IN SMALL CRAFT ADVISORY CONDITIONS OVER THE
TIDAL LAKES AND GULF WATERS TONIGHT. A SMALL CRAFT ADVISORY IS IN
EFFECT BEGINNING AT 7 PM CDT THIS EVENING.

RIVER FLOODING...MINOR TO MODERATE FLOODING WILL CONTINUE ON THE
MISSISSIPPI RIVER NEAR RED RIVER LANDING AND BATON ROUGE. MINOR
FLOODING WILL ALSO CONTINUE ON THE ATCHAFALAYA RIVER NEAR MORGAN
CITY. PLEASE REFER TO THE LATEST RIVER FLOOD STATEMENTS FOR
DETAILS.

.DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY
MARINE HAZARDS...A SMALL CRAFT ADVISORY WILL REMAIN IN EFFECT
MONDAY THROUGH TUESDAY NIGHT DUE TO STRONG NORTHERLY OR
NORTHEASTERLY WINDS AND SEAS OF UP TO 9 FEET. THE MOST DANGEROUS
CONDITIONS CAN BE EXPECTED IN THE OUTER GULF WATERS.

A SURFACE LOW IS FORECAST TO DEVELOP OVER THE CENTRAL OR EASTERN
GULF OF MEXICO TOWARD MIDWEEK. BY THURSDAY OR FRIDAY...DEPENDING
ON THE PATH THAT THIS LOW TAKES...IT MAY BE CAPABLE OF PRODUCING
HEAVY RAINFALL AND SOME COASTAL FLOODING PROBLEMS ACROSS THE
NORTHERN GULF COAST. FUTURE FORECASTS WILL REFINE THE DETAILS OF
THE WEATHER ASSOCIATED WITH THIS SYSTEM. ADDITIONALLY...THE WINDS
ASSOCIATED WITH THIS LOW MAY RESULT IN SMALL CRAFT ADVISORY
CONDITIONS OVER THE COASTAL WATERS.

RIVER FLOODING...MINOR TO MODERATE FLOODING WILL CONTINUE ON THE
MISSISSIPPI RIVER NEAR RED RIVER LANDING AND BATON ROUGE.
ADDITIONALLY...THE MISSISSIPPI RIVER IS EXPECTED TO RISE ABOVE
FLOOD STAGE NEAR DONALDSONVILLE ON THURSDAY AND REMAIN ABOVE FLOOD
STAGE THROUGH THE END OF THE WEEK. MINOR FLOODING WILL ALSO
CONTINUE ON THE ATCHAFALAYA RIVER NEAR MORGAN CITY. PLEASE REFER
TO THE LATEST RIVER FLOOD STATEMENTS FOR DETAILS.

.SPOTTER INFORMATION STATEMENT...
SPOTTER ACTIVATION IS NOT EXPECTED AT THIS TIME.

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE NEW ORLEANS LA
909 AM CDT SUN MAY 17 2009

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

0750 AM     WATER SPOUT      39 E VENICE             29.28N 88.71W
05/17/2009                   GMZ555             LA   TRAINED SPOTTER

            2 SOUTH OF MAIN PASS BLOCK 142C /MAIN PASS 299/. MEMBER
            OF SPOTTERNETWORK.ORG REPORTED PERSISTENT WATERSPOUT
            LASTED AT LEAST 15 MINUTES BEFORE DISSIPATING. MOVED VERY
            SLOWLY WESTWARD NOT MORE THAN 0.5 MILES DURING LIFETIME
            OF EVENT. RECEIVED VIA WEB ENTRY AT 850 AM CDT.

&&

24/RR