Tornado Warning 35, NWS New Orleans, LA

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEW ORLEANS LA
332 PM CDT WED OCT 27 2010

.SYNOPSIS...
DEEP 974 MB SURFACE LOW IS CENTERED OVER SOUTHERN ONTARIO JUST
NORTHEAST OF MINNESOTA. A STATIONARY FRONT EXTENDS FROM SOUTHWEST
VIRGINIA THROUGH THE LOWER MISSISSIPPI VALLEY AND INTO SOUTHERN
TEXAS. A SECONDARY COLD FRONT IS CURRENTLY LOCATED ACROSS THE
MIDDLE MISSISSIPPI VALLEY...AND SURFACE HIGH PRESSURE IS CENTERED
OVER THE FOUR CORNERS REGION.

LOCALLY...MODERATE SOUTHERLY WINDS CONTINUE TO RESULT IN HIGHER THAN
NORMAL TEMPERATURES AND DEWPOINTS. SCATTERED SHOWERS ARE MOVING
NORTHEASTWARD ACROSS THE AREA.

&&

.SHORT TERM...
THE COLD FRONT WILL CONTINUE ITS PROGRESSION TOWARD THE AREA
TONIGHT. EXPECT WIND SHIFT TO ARRIVE FIRST...AROUND MIDNIGHT ACROSS
THE NORTHWESTERN PORTION OF THE FORECAST AREA...AND CLOSER TO DAY
BREAK ACROSS THE SOUTHEASTERN PORTION OF THE AREA. DRY AIR WILL LAG
BY A FEW HOURS...BUT EXPECT SIGNIFICANT DRY AIR ADVECTION DURING
DAYLIGHT HOURS THURSDAY. DEWPOINTS ARE FORECAST TO DROP
QUICKLY...FROM THE UPPER 50S AND 60S NEAR DAY BREAK TO 30S AND 40S
BY MID AFTERNOON. AFTERNOON HIGHS SHOULD TOP OUT IN THE UPPER 70S
AND LOWER 80S. STRONG NORTHERLY WINDS WILL ALSO CONTRIBUTE TO
DANGEROUS FIRE CONDITIONS. SEE FIRE WEATHER SECTION OF THE AFD FOR
MORE INFORMATION.

STRONG COLD AIR ADVECTION SETS IN THURSDAY NIGHT AS THE HIGH BUILDS
INTO THE AREA. COMPARED TO TONIGHT/S TEMPERATURES...OVERNIGHT LOWS
THURSDAY NIGHT AND FRIDAY NIGHT ARE FORECAST TO BE 20 TO 25 DEGREES
COLDER ACROSS THE NORTHERN HALF OF THE AREA AND 15 TO 20 DEGREES
COLDER ACROSS THE SOUTHERN HALF OF THE AREA. ADDITIONALLY...
AFTERNOON TEMPERATURES WILL STRUGGLE TO REACH EVEN THE LOW 70S ON
FRIDAY.

.LONG TERM...
EXPECT SOME MODIFICATION OF THE AIR MASS TO TAKE PLACE BY SUNDAY AS
WINDS BECOME SOUTHEASTERLY ONCE AGAIN. TEMPERATURES SHOULD INCREASE
BY A FEW DEGREES EACH DAY SUNDAY AND MONDAY.

BY TUESDAY...AN UPPER TROUGH/LOW WILL DIVE INTO THE LOWER
MISSISSIPPI VALLEY. MODEL GUIDANCE SUGGESTS THAT THE LOW WILL BECOME
CUT OFF AND REMAIN NEARLY STATIONARY FOR ABOUT A DAY BEFORE LIFTING
OUT. THE LOW SHOULD FORCE ANOTHER COLD FRONT THROUGH THE AREA SOME
TIME TUESDAY OR WEDNESDAY. THERE ARE SOME SIGNIFICANT MODEL
DIFFERENCES CONCERNING THE LOCATION AND STRENGTH OF THIS SYSTEM...
RESULTING IN LOWER THAN USUAL FORECAST CONFIDENCE IN THE FAR
EXTENDED PERIOD. FOR THE TIME BEING...WILL CARRY SLIGHT CHANCE POPS
FOR THE TUESDAY AND WEDNESDAY TIME FRAME KNOWING THAT THEY WILL NEED
TO BE TWEAKED AND NARROWED DOWN ONCE THE DETAILS OF THE SYSTEM
BECOME A BIT CLEARER.

&&

.AVIATION...
MVFR CATEGORY CIGS AND VIS DUE TO WX ARE THE MAIN AVIATION PROBLEMS
THIS AFTERNOON. TEMPO LOWER VSBYS WILL BE ASSOCIATED WITH SCATTERED
SHRA ACTIVITY AND AREAS WITH NO RAIN MAY SEE MIST AND LOW CLOUDS.
DRIER CONDITIONS AND CLEAR VFR FLYING WILL RETURN THURSDAY MORNING
IN THE WAKE OF A STRONG COLD FRONT. IN ADDITION...BRISK NORTH WINDS
OF 10 TO 15 KNOTS WITH GUSTS UP TO 25 KNOTS WILL OCCUR AT ALL TAF
SITES THURSDAY MORNING INTO THURSDAY AFTERNOON.

&&

.MARINE...
A STRONG COLD FRONT IS EXPECTED TO PUSH THROUGH THE CENTRAL GULF
COAST REGION EARLY THURSDAY MORNING. STRONG NORTH TO NORTHEAST WINDS
OF 20 TO 25 KNOTS WITH HIGHER GUSTS ARE EXPECTED LATE THURSDAY
MORNING THROUGH MIDDAY FRIDAY AS THE MUCH COOLER AND DRIER AIRMASS
MOVES OFFSHORE. SMALL CRAFT ADVISORIES WILL BE ISSUED WITH THIS
PACKAGE FOR TIDAL LAKES AND COASTAL WATERS THURSDAY MORNING THROUGH
FRIDAY NOON. THE HIGH PRESSURE AREA AND COOL AIRMASS WILL SETTLE
OVER THE LOWER MISSISSIPPI VALLEY AND SOUTHEAST U.S. FRIDAY NIGHT
AND SATURDAY BEFORE MOVING EAST LATER SUNDAY INTO MONDAY. THE VERY
COOL AIR WILL LIKELY PRODUCE STRONGER WINDS THAN NORMALLY SUPPORTED
BY THE PRESSURE GRADIENT THROUGH EARLY SATURDAY MORNING BEFORE THE
AIRMASS GRADUALLY MODIFIES LATER SATURDAY THROUGH EARLY NEXT WEEK.

&&

.FIRE WEATHER...
STRONG FRONTAL PASSAGE IS EXPECTED THURSDAY MORNING BETWEEN 09 AND
13Z FOR SOUTHERN MISSISSIPPI AND 10 AND 14Z FOR SOUTHEAST
LOUISIANA. A VERY DRY AIR MASS WILL MOVE INTO THE AREA BEHIND THE
STRONG COLD FRONT. DEWPOINTS ARE FORECAST TO DROP INTO THE 30S
ACROSS MUCH OF THE AREA. WITH AFTERNOON TEMPERATURES FORECAST TO
RISE TO NEAR OR JUST ABOVE 80 DEGREES...AFTERNOON RELATIVE
HUMIDITY VALUES SHOULD PLUMMET TO NEAR 20 PERCENT ACROSS THE
NORTHERN HALF OF THE AREA AND TO NEAR 30 PERCENT ACROSS THE
SOUTHERN HALF OF THE AREA. SIMILAR CONDITIONS ARE EXPECTED FRIDAY
AFTERNOON. COMPOUNDING MATTERS ON THURSDAY WILL BE NORTHERLY WINDS
OF AROUND 15 MPH BEHIND THE FRONT WITH SLIGHTLY HIGHER WINDS SOUTH
OF THE TIDAL LAKES. THE COMBINATION OF LOW RELATIVE HUMIDITY AND
MODERATE TO STRONG WINDS WILL LEAD TO DANGEROUS FIRE CONDITIONS
ACROSS THE AREA.

A FIRE WEATHER WATCH HAS BEEN ISSUED FOR PORTIONS OF SOUTHEAST
LOUISIANA AND SOUTHERN MISSISSIPPI THAT ARE GENERALLY ALONG AND
NORTH OF THE INTERSTATE 10/12 CORRIDOR. ADDITIONALLY...BURN BANS
REMAIN IN EFFECT FOR THE ENTIRE STATES OF LOUISIANA AND MISSISSIPPI.

&&

.PRELIMINARY POINT TEMPS/POPS...
MCB  61  77  40  70 /  50  10   0   0
BTR  66  79  43  72 /  50  10   0   0
ASD  68  81  43  71 /  60  20   0   0
MSY  68  80  53  71 /  60  20   0   0
GPT  68  82  45  72 /  60  20   0   0
PQL  68  82  42  72 /  50  20   0   0

&&

.LIX WATCHES/WARNINGS/ADVISORIES...
LA...FIRE WEATHER WATCH FROM 6 AM THURSDAY TO 6 PM THURSDAY FOR THE
     FOLLOWING ZONES: ASCENSION...EAST BATON ROUGE...EAST
     FELICIANA...IBERVILLE...LIVINGSTON...POINTE COUPEE...ST.
     HELENA...ST. TAMMANY...TANGIPAHOA...WASHINGTON...WEST BATON
     ROUGE...AND WEST FELICIANA.

MS...FIRE WEATHER WATCH FROM 6 AM THURSDAY TO 6 PM THURSDAY FOR THE
     FOLLOWING ZONES:
     AMITE...HANCOCK...HARRISON...JACKSON...PEARL
     RIVER...PIKE...WALTHALL...AND WILKINSON.

GM...SMALL CRAFT ADVISORY FROM 9 AM THURSDAY TO 1 PM FRIDAY FOR THE
     FOLLOWING ZONES: BRETON SOUND...CHANDELEUR SOUND...COASTAL
     WATERS FROM BOOTHVILLE LA TO THE SOUTHWEST PASS OF THE
     MISSISSIPPI RIVER OUT 20 NM...COASTAL WATERS FROM
     PASCAGOULA MS TO STAKE ISLAND LA FROM 20 TO 60 NM...COASTAL
     WATERS FROM PASCAGOULA MS TO STAKE ISLAND LA OUT 20
     NM...COASTAL WATERS FROM STAKE ISLAND LA TO THE SOUTHWEST
     PASS OF THE MISSISSIPPI RIVER FROM 20 TO 60 NM...COASTAL
     WATERS FROM THE PORT FOURCHON TO LOWER ATCHAFALAYA RIVER
     FROM 20 TO 60 NM...COASTAL WATERS FROM THE PORT FOURCHON TO
     LOWER ATCHAFALAYA RIVER OUT 20 NM...COASTAL WATERS FROM THE
     SOUTHWEST PASS OF THE MISSISSIPPI RIVER TO PORT FOURCHON
     FROM 20 TO 60 NM...COASTAL WATERS FROM THE SOUTHWEST PASS
     OF THE MISSISSIPPI RIVER TO PORT FOURCHON OUT 20 NM...LAKE
     BORGNE...LAKE PONTCHARTRAIN AND LAKE MAUREPAS...AND
     MISSISSIPPI SOUND.

&&

AVIATION/MARINE...18
REST OF DISCUSSION...95/DM

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE NEW ORLEANS LA
1105 AM CDT WED OCT 27 2010

GMZ530-532-534-536-538-550-552-555-557-570-572-575-577-LAZ034>040-
046>050-056>070-MSZ068>071-077-080>082-281615-
LAKE PONTCHARTRAIN AND LAKE MAUREPAS-MISSISSIPPI SOUND-
LAKE BORGNE-CHANDELEUR SOUND-BRETON SOUND-
COASTAL WATERS FROM THE PORT FOURCHON TO LOWER ATCHAFALAYA RIVER
OUT 20 NM-
COASTAL WATERS FROM THE SOUTHWEST PASS OF THE MISSISSIPPI RIVER
TO PORT FOURCHON OUT 20 NM-
COASTAL WATERS FROM BOOTHVILLE LA TO THE SOUTHWEST PASS OF THE
MISSISSIPPI RIVER OUT 20 NM-
COASTAL WATERS FROM PASCAGOULA MS TO STAKE ISLAND LA OUT 20 NM-
COASTAL WATERS FROM THE PORT FOURCHON TO LOWER ATCHAFALAYA RIVER
FROM 20 TO 60 NM-
COASTAL WATERS FROM THE SOUTHWEST PASS OF THE MISSISSIPPI RIVER
TO PORT FOURCHON FROM 20 TO 60 NM-
COASTAL WATERS FROM STAKE ISLAND LA TO THE SOUTHWEST PASS OF THE
MISSISSIPPI RIVER FROM 20 TO 60 NM-
COASTAL WATERS FROM PASCAGOULA MS TO STAKE ISLAND LA 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-
1105 AM CDT WED OCT 27 2010

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...
ISOLATED TO SCATTERED THUNDERSTORMS WILL BE POSSIBLE TODAY AHEAD
OF AN APPROACHING COLD FRONT. SEVERE WEATHER IS NOT EXPECTED...BUT
A FEW STORMS COULD BECOME STRONG...PRODUCING GUSTY WINDS AND
FREQUENT LIGHTNING.

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY
THUNDERSTORMS...
SCATTERED TO NUMEROUS THUNDERSTORMS WILL BE POSSIBLE THURSDAY
MORNING AS A COLD FRONT MOVES THROUGH THE AREA. SEVERE WEATHER IS
NOT EXPECTED...BUT A FEW STORMS MAY BECOME STRONG...PRODUCING
GUSTY WINDS AND FREQUENT LIGHTNING.

FIRE WEATHER...
A VERY DRY AIR MASS COMBINED WITH STRONG WINDS BEHIND A COLD FRONT
WILL PRODUCE DANGEROUS FIRE CONDITIONS...ESPECIALLY ON THURSDAY
AND FRIDAY. BURN BANS REMAIN IN EFFECT FOR THE STATES OF LOUISIANA
AND MISSISSIPPI.

MARINE...
SMALL CRAFT ADVISORIES MAY BE NEEDED THURSDAY AND FRIDAY DUE TO
STRONG WINDS FOLLOWING A COLD FRONTAL PASSAGE.

.SPOTTER INFORMATION STATEMENT...
SPOTTER ACTIVATION WILL NOT BE NEEDED.

95/DM

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE NEW ORLEANS LA
457 PM CDT WED OCT 27 2010

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

0438 PM     FUNNEL CLOUD     GULFPORT                30.39N 89.07W
10/27/2010                   HARRISON           MS   LAW ENFORCEMENT

            GULFPORT POLICE DEPARTMENT ALONG WITH A TRAINED SPOTTER
            REPORTED A FUNNEL CLOUD JUST NORTH OF MILE MARKER 32 ON
            INTERSTATE 10 IN GULFPORT. THIS IS NEAR THE SPORTSPLEX
            AND WATERPARK.

&&

PGRIGSBY