Severe Thunderstorm Warning 124, NWS New Orleans, LA

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE NEW ORLEANS/BATON ROUGE LA
915 PM CST SUN NOV 10 2002

LATEST UPPER AIR ANALYSIS AT 200MB CONTINUE TO SHOW A 125 KT JET MAX
FROM SOUTH INDIANA TO NORTH TEXAS. LOW LEVEL JET OF 40 KNOTS WAS
LOCATED ACROSS CENTRAL AND SOUTHEAST LOUISIANA TO THE MID ATLANTIC
STATES. WIND FLOW OVER THE FORECAST AREA WAS GENERALLY OUT OF THE
SOUTHWEST FROM THE SURFACE TO 200MB AND THE SPEED SHEAR WAS
PRODUCING LINEAR CONVECTION AT THIS TIME. THE 2ND RELEASE LIX
SOUNDING REVEALED AN IMPRESSIVE INVERSION FROM 820MB TO 775MB WITH
AN ISOTHERMAL LAYER. LIX SOUNDING STORM RELATIVE HELICITY FROM THE
SURFACE TO 3KM WAS 249 M2/S2 WHILE JACKSON SOUNDING SHOWED AN
IMPRESSIVE HELICITY VALUE OF 427 M2/S2. CONVECTION TO THE NORTH AND
WEST WAS JET INDUCED. AS THE UPPER LEVEL DYNAMICS APPROACH THE
FORECAST AREA...CONVECTION IS EXPECTED TO MOVE EAST...IGNORING THE
CAP. IN ADDITION...WESTERLY FLOW IN THE MID LAYER TOWARD MIDNIGHT
WILL HELP PRODUCE A MORE DIRECTIONAL SHEAR ENVIRONMENT. DO EXPECT
MORE ACTIVITY ACROSS THE NORTH HALF OF THE FORECAST AREA...POSSIBLY
SEVERE WITH ISOLATED TORNADOES AND BOW ECHOES OVERNIGHT ALONG THE
NORTHERN HALF OF THE FORECAST AREA. AFTERNOON FORECAST PACKAGE IS OK
FOR NOW.

.NEW...SMALL CRAFT ADVISORY PQL TO ATCHAFALAYA RIVER INCLUDING
       LAKES PONTCHARTRAIN AND MAUREPAS
LA...TORNADO WATCH NUMBER 752 FOR LAZ034>040-046>050 TIL 03Z.
MS...TORNADO WATCH NUMBER 752 FOR MSZ068>071-077-080>082 TIL 03Z.

18

LAZ034>040-046>050-056>070-MSZ068>071-077-080>082-111200-

HAZARDOUS WEATHER OUTLOOK...RETRANSMISSION...
NATIONAL WEATHER SERVICE NEW ORLEANS LA
1000 PM CST SUN NOV 10 2002

THIS HAZARDOUS WEATHER OUTLOOK IS FOR SOUTHEAST LOUISIANA AND
EXTREME SOUTHWEST AND COASTAL MISSISSIPPI.

.TONIGHT...
A TORNADO WATCH IS IN EFFECT UNTIL 3 AM MONDAY MORNING FOR EAST
CENTRAL LOUISIANA...SOUTHEAST LOUISIANA NORTH OF LAKE
PONTCHARTRAIN...EXTREME SOUTH MISSISSIPPI AND COASTAL MISSISSIPPI.
THUNDERSTORMS ARE EXPECTED TO DEVELOP ACROSS SOUTHEAST LOUISIANA AND
SOUTH MISSISSIPPI OVERNIGHT. SOME OF THE THUNDERSTORMS MAY BE
SEVERE AND PRODUCE DAMAGING WINDS...LARGE HAIL AND ISOLATED
TORNADOES. A MODERATE RISK OF SEVERE WEATHER EXISTS TONIGHT ACROSS
SOUTHEAST LOUISIANA NORTH OF INTERSTATE 12 AND SOUTH MISSISSIPPI
INCLUDING COASTAL SECTIONS. A SLIGHT RISK OF SEVERE WEATHER EXISTS
TONIGHT ACROSS THE REMAINDER OF SOUTHEAST LOUISIANA.

MARINE HAZARDS...
A SMALL CRAFT ADVISORY IS IN EFFECT ACROSS THE COASTAL WATERS OUT
60 NM TONIGHT FOR SOUTHWEST WINDS AROUND 20 KNOTS WITH GUSTS TO 25
KNOTS AND SEAS TO 7 FEET.

FLOODING...
THE LOWER PEARL RIVER BASIN REMAINS IN FLOOD. REFER TO THE LATEST
RIVER FLOOD STATEMENTS FOR MORE DETAILS.

.SPOTTER CALL TO ACTION STATEMENT...
ACTIVATION OF EMERGENCY MANAGEMENT OFFICIALS AND STORM SPOTTERS...IN
SUPPORT OF SEVERE WEATHER OPERATIONS...MAY BE REQUIRED OVERNIGHT.
STAY ABREAST OF THE LATEST FORECASTS CONCERNING POSSIBLE ACTIVATION.

.MONDAY THROUGH SATURDAY...
MARINE CONDITIONS MAY IMPROVE BRIEFLY MONDAY BUT STRONG NORTHERLY
WINDS AND HIGH SEAS ARE EXPECTED BY DAYBREAK TUESDAY AS STRONG COLD
HIGH PRESSURE BUILDS INTO THE GULF OF MEXICO. THERE IS ALSO A SLIGHT
RISK OF SEVERE THUNDERSTORMS POSSIBLY CAPABLE OF PRODUCING
ISOLATED TORNADOES MONDAY EVENING ACROSS PLAQUEMINES AND ST BERNARD
PARISHES AND THE MISSISSIPPI COASTAL COUNTIES.