Severe Thunderstorm Warning 192, NWS New Orleans, LA

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEW ORLEANS LA
700 PM CST TUE NOV 15 2005

.UPDATE...TORNADO WATCH NUMBER 871 IS IN EFFECT FOR EAST CENTRAL
LOUISIANAN AND PORTIONS OF EXTREME SOUTH MISSISSIPPI TIL 07Z. UPDATED
HAZARD GRIDS AND UPDATED ZONES WILL BE TRANSMITTED SHORTLY.

&&

.PREV DISCUSSION... (ISSUED 213 PM CST TUE NOV 15 2005)

DISCUSSION...
MAIN CONCERN IN THE SHORT TERM IS THE POSSIBILITY OF SEVERE
WEATHER THROUGH THE FIRST PERIOD. CONVECTION HAS DEVELOP ALONG AND
IN ADVANCE OF A STRONG COLD FRONT EXTENDING FROM CENTRAL ARKANSAS
TO EXTREME NORTHWEST LOUISIANA AND EAST TEXAS EARLY THIS AFTERNOON.
THIS COLD FRONT WILL PUSH EAST ACROSS THE FORECAST AREA THIS
EVENING AND OVERNIGHT AS A SHARP UPPER TROUGH AND MID/UPPER LOW
OVER THE CENTRAL CONUS PULLS OFF TO THE NORTHEAST INTO THE GREAT
LAKES...OHIO VALLEY AND TENNESSEE VALLEY REGIONS OVERNIGHT AND
INTO WEDNESDAY. THE GREATEST THREAT FOR SEVERE WEATHER SHOULD
REMAIN TO THE NORTH OF THE FORECAST AREA WHERE THE BEST DYNAMICS
...MORE FAVORABLE UPPER AND LOWER JET CONFIGURATION...AND BEST
SHEAR WILL RESIDE. IT IS IN THIS AREA THAT THE GREATEST THREAT OF
TORNADIC STORMS WILL BE. THE GREATEST THREATS ACROSS THE LOCAL
FORECAST AREA WILL BE STRONG DAMAGING WINDS ASSOCIATED WITH THE
SQUALL LINE NEAR THE COLD FRONT AS IT PASSES THROUGH DURING THE
EVENING AND OVERNIGHT HOURS ASSUMING THAT SUBSTANTIAL INSTABILITY
REMAINS ACROSS THE AREA. ISOLATED TORNADOES WILL ALSO BE POSSIBLE...
HOWEVER VEERING WINDS IN THE LOW LEVELS WILL MAKE THIS LESS LIKELY
AS TIME PROGRESSES. THE BEST CHANCE FOR ANY TORNADIC ACTIVITY WILL
OCCUR EARLY IN THE PERIOD IN ASSOCIATION WITH CELLS OUT AHEAD OF
THE SQUALL LINE.

IN THE WAKE OF THE CONVECTION AND COLD FRONT DURING THE FIRST PERIOD...
THE MAIN NEWS WILL BE MUCH COLDER TEMPERATURES. SOME OF THE
COOLEST AIR OF THE SEASON SO FAR WILL BEGIN TO FILTER INTO THE
FORECAST AREA LATE TONIGHT AND WEDNESDAY WITH TEMPERATURES
EXPECTED TO REMAIN BELOW NORMAL THROUGH THE WEEKEND AND INTO EARLY
NEXT WEEK AS AN UPPER TROUGH DOMINATES THE EASTERN CONUS DURING
MUCH OF THE PERIOD WITH THE COOL AIR BEING REINFORCED FROM TIME
TO TIME. MINIMUM TEMPERATURES MAY FLIRT WITH THE FREEZING MARK
ACROSS THE NORTHERN ZONES WEDNESDAY NIGHT AND THURSDAY NIGHT WITH
HIGH TEMPERATURES BOTH WEDNESDAY AND THURSDAY BEING CONFINED TO
THE MID AND UPPER 50S.

STRONG GRADIENT WINDS AND COLD AIR DRAINAGE WILL RESULT IN SMALL
CRAFT ADVISORY CONDITIONS DEVELOPING BEHIND THE COLD FRONT LATER
TONIGHT AND CONTINUING INTO THURSDAY.

&&

.LIX WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
MS...NONE.
GM...SMALL CRAFT ADVISORY FROM MIDNIGHT TONIGHT TO 6 PM
     CST THURSDAY FOR GMZ550-GMZ555-GMZ570-GMZ575.

     SMALL CRAFT ADVISORY FROM MIDNIGHT TONIGHT TO 6 AM CST THURSDAY
     FOR GMZ530.

&&

11/18

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE NEW ORLEANS LA
1100 AM CST TUE NOV 15 2005

MSZ068>071-161100-
WILKINSON-AMITE-PIKE-WALTHALL-
1100 AM CST TUE NOV 15 2005

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF SOUTHERN
MISSISSIPPI.

.DAY ONE...THIS AFTERNOON AND TONIGHT

SEVERE WEATHER...
THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS THIS EVENING
MAINLY BETWEEN 5 PM AND 9 PM. THE PRIMARY THREAT WILL BE ISOLATED
TORNADOES SPAWNED FROM ISOLATED SUPERCELLS MOVING AHEAD OF A
SQUALL LINE THAT IS EXPECTED TO DEVELOP AND MOVE ACROSS THE AREA
THIS EVENING. DAMAGING WINDS GUSTS OF 55 TO 70 MPH...LARGE HAIL
UP TO GOLFBALL DIAMETERS...FREQUENT LIGHTNING AND LOCALLY HEAVY
RAINFALL ARE ALSO POSSIBLE. THE THREAT OF SEVERE WEATHER WILL END
WITH A STRONG COLD FRONTAL PASSAGE BY MIDNIGHT TONIGHT.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY

MARINE HAZARDS...
A SMALL CRAFT ADVISORY WILL BE IN EFFECT WEDNESDAY THROUGH
THURSDAY AS COLD HIGH PRESSURE BUILDS BEHIND THE COLD
FRONT...BRINGING STRONG NORTH WINDS AND OCCASIONAL GALE FORCE
GUSTS OVER THE COASTAL WATERS.

.SPOTTER INFORMATION STATEMENT...
THE ACTIVATION OF STORM SPOTTERS...HAM RADIO OPERATORS AND
EMERGENCY MANAGEMENT PERSONNEL IS BEING REQUESTED FOR LATER THIS
AFTERNOON AND THIS EVENING IN SUPPORT OF SEVERE WEATHER
OPERATIONS. LAW ENFORCEMENT OFFICIALS AND EMERGENCY MANAGERS ARE
URGED TO NOTIFY THE NATIONAL WEATHER SERVICE IN SLIDELL IF ANY
SEVERE WEATHER IS NOTED IN YOUR JURISDICTIONS. CITIZENS SHOULD
REVIEW PREPAREDNESS MEASURES AND BE PREPARED TO TAKE ACTIONS IF
WARNINGS ARE ISSUED LATER THIS AFTERNOON AND EVENING.
ALSO...REMEDIAL ROOF REPAIRS SHOULD BE SECURELY FASTENED TO AVOID
ADDITIONAL WATER DAMAGE TO PROPERTY.

LAZ034>040-046>050-056>070-MSZ077-080>082-161100-
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-PEARL RIVER-HANCOCK-HARRISON-
JACKSON-
1100 AM CST TUE NOV 15 2005

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

.DAY ONE...THIS AFTERNOON AND TONIGHT

SEVERE THUNDERSTORMS...
THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS DEVELOPING LATE
THIS AFTERNOON...MAINLY BETWEEN 5 PM AND 8 PM IN EAST-CENTRAL
LOUISIANA AND BETWEEN 8 PM AND 2 AM IN SOUTHEAST LOUISIANA AND
SOUTHERN MISSISSIPPI. THE PRIMARY THREAT WILL BE DAMAGING WIND
GUSTS OF 55 TO 70 MPH AND LARGE HAIL BETWEEN PENNY AND QUARTER
DIAMETERS. ISOLATED BRIEF TORNADOES SPAWNED ALONG THE SQUALL LINE
OR FROM ISOLATED SUPERCELLS AHEAD OF THE SQUALL LINE MAY ALSO
OCCUR. FREQUENT LIGHTNING AND LOCALLY HEAVY RAINFALL ARE ALSO
POSSIBLE. THE THREAT OF SEVERE WEATHER WILL END WITH A STRONG COLD
FRONTAL PASSAGE BETWEEN MIDNIGHT AND DAYBREAK.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY

MARINE HAZARDS...
A SMALL CRAFT ADVISORY WILL BE IN EFFECT WEDNESDAY THROUGH
THURSDAY AS COLD HIGH PRESSURE BUILDS BEHIND THE COLD
FRONT...BRINGING STRONG NORTH WINDS AND OCCASIONAL GALE FORCE
GUSTS OVER THE COASTAL WATERS.

.SPOTTER INFORMATION STATEMENT...
THE ACTIVATION OF STORM SPOTTERS...HAM RADIO OPERATORS AND
EMERGENCY MANAGEMENT PERSONNEL IS BEING REQUESTED FOR LATER THIS
AFTERNOON AND THIS EVENING IN SUPPORT OF SEVERE WEATHER
OPERATIONS. LAW ENFORCEMENT OFFICIALS AND EMERGENCY MANAGERS ARE
URGED TO NOTIFY THE NATIONAL WEATHER SERVICE IN SLIDELL IF ANY
SEVERE WEATHER IS NOTED IN YOUR JURISDICTIONS. CITIZENS SHOULD
REVIEW PREPAREDNESS MEASURES AND BE PREPARED TO TAKE ACTIONS IF
WARNINGS ARE ISSUED LATER THIS EVENING. ALSO...REMEDIAL ROOF
REPAIRS SHOULD BE SECURELY FASTENED TO AVOID ADDITIONAL WATER
DAMAGE TO PROPERTY.