Flash Flood Warning 74, NWS New Orleans, LA

Area Forecast Discussion
National Weather Service New Orleans LA
343 PM CDT MON AUG 22 2016

.DISCUSSION...
Generally only minor tweaks made to the forecast with this
package as latest short term guidance is in line with going
forecast and longer term forecast remains more uncertain.

Frontal boundary remains stalled north of the local area and will
remain there for the next few days as it dissipates. Despite upper
ridging building into the area, mid level warm nose does not
appear strong enough to completely preclude convection, so am
still expecting isolated to scattered showers and thunderstorms
each day through the period. Highest coverage looks to be on
Wednesday and Thursday as some enhanced moisture moves through the
area around the southern periphery of the ridge.

Going into the weekend, models continue to diverge concerning
whether the upper ridge will move far enough away from the local
area to allow tropical waves and associated moisture to affect the
local area. Have generally continued to carry a blend of available
guidance with a slight preference for the drier solutions. This
results in a continued 20 to 30 percent chance of showers and
thunderstorms each day.

Very little change in temperatures throughout the period. Expect
overnight lows to be near or slightly above normal with afternoon
highs right around normal.

&&

.AVIATION...
Isolated convection has started to develop around tidal lakes and
mainly around KASD...KHDC...KMSY and KNEW. Will maintain VCTS for
these sites through 01z. For Tuesday morning...some patchy fog may
develop again at a few terminals mainly KMCB...KHUM and possibly
KHDC...KASD.

&&

.MARINE...
A weak cold frontal boundary will remain stalled north of the
coastal waters today, dissipating by mid week. Expect winds to
remain generally 10 knots or less through mid week. By thursday
easterly flow should be set in, with some strengthening into the
10 to 15 knot range. Waves should be 2 feet or less through
Wednesday with some building during the latter part of the week.

&&

.DECISION SUPPORT...
DSS code: Yellow
Deployed: None.
Activation: None.
Activities: Flood recovery support

Decision Support Services (DSS) Code Legend
Green  = No weather impacts that require action.
Blue   = Long-fused watch, warning, or advisory in effect or
         high visibility event.
Yellow = Heightened impacts with short-fused watch, warning
         or advisory issuances; radar support.
Orange = High Impacts; Slight to Moderate risk severe; nearby
         tropical events; HazMat or other large episodes.
Red    = Full engagement for Moderate risk of severe and/or
         direct tropical threats; Events of National Significance.

&&

.PRELIMINARY POINT TEMPS/POPS...
MCB  73  92  74  92 /  20  30  20  50
BTR  74  92  74  92 /  20  30  20  40
ASD  74  93  74  94 /  20  30  20  40
MSY  77  91  77  91 /  20  30  20  40
GPT  76  92  76  91 /  20  30  20  40
PQL  74  93  74  93 /  20  20  20  40

&&

.LIX Watches/Warnings/Advisories...
LA...None.
GM...None.
MS...None.
GM...None.
&&

Aviation...18
Rest of Discussion...95/DM

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE NEW ORLEANS LA
516 PM CDT MON AUG 22 2016

GMZ530-532-534-536-538-550-552-555-557-570-572-575-577-LAZ034>037-
039-040-046>050-056>072-MSZ068>071-077-080>082-231030-
LAKE PONTCHARTRAIN AND LAKE MAUREPAS-MISSISSIPPI SOUND-
LAKE BORGNE-CHANDELEUR SOUND-BRETON SOUND-
COASTAL WATERS FROM PORT FOURCHON LA TO LOWER ATCHAFALAYA RIVER
LA OUT 20 NM-
COASTAL WATERS FROM THE SOUTHWEST PASS OF THE MISSISSIPPI RIVER
TO PORT FOURCHON LOUISIANA OUT 20 NM-
COASTAL WATERS FROM BOOTHVILLE LA TO SOUTHWEST PASS OF THE
MISSISSIPPI RIVER OUT 20 NM-
COASTAL WATERS FROM PASCAGOULA MISSISSIPPI TO STAKE ISLAND OUT
20 NM-
COASTAL WATERS FROM PORT FOURCHON LOUISIANA TO LOWER ATCHAFALAYA
RIVER LA FROM 20 TO 60 NM-
COASTAL WATERS FROM SOUTHWEST PASS OF THE MISSISSIPPI RIVER TO
PORT FOURCHON LOUISIANA FROM 20 TO 60 NM-
COASTAL WATERS FROM STAKE ISLAND LA TO SOUTHWEST PASS OF THE
MISSISSIPPI RIVER FROM 20 TO 60 NM-
COASTAL WATERS FROM PASCAGOULA MISSISSIPPI TO STAKE ISLAND
LOUISIANA OUT 20 TO 60 NM-POINTE COUPEE-WEST FELICIANA-
EAST FELICIANA-ST. HELENA-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-NORTHERN TANGIPAHOA-
SOUTHERN TANGIPAHOA-WILKINSON-AMITE-PIKE-WALTHALL-PEARL RIVER-
HANCOCK-HARRISON-JACKSON-
516 PM CDT MON AUG 22 2016

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

.DAY ONE...TONIGHT

ISOLATED SHOWERS AND THUNDERSTORMS WILL CONTINUE TO DEVELOP THIS
AFTERNOON AND INTO THE EARLY EVENING HOURS. SOME OF THESE STORMS
COULD PRODUCE LOCALLY HEAVY RAINFALL...FREQUENT LIGHTNING
STRIKES...AND GUSTY WINDS.

LOWER PORTIONS OF THE AMITE RIVER BASIN TOWARD LAKE MAUREPAS
CONTINUE TO BE IMPACTED BY FLOODING. SOME TRIBUTARIES IN EAST
BATON ROUGE...IBERVILLE...ASCENSION...LIVINGSTON...ST.
JAMES...AND ST. JOHN THE BAPTIST PARISHES ARE EXPERIENCING
BACKWATER FLOODING. PLEASE REFER TO FLOOD WARNINGS...ADVISORIES
AND STATEMENTS FOR THE LATEST INFORMATION.

.DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY

SCATTERED...MOSTLY LATE MORNING AND AFTERNOON SHOWERS AND
THUNDERSTORMS ARE EXPECTED THROUGH THURSDAY...THEN ONLY ISOLATED
SHOWERS AND THUNDERSTORMS ARE FORECAST FRIDAY AND SATURDAY.

A FEW STRONG THUNDERSTORMS COULD DEVELOP EACH DAY AND PRODUCE
LOCALLY HEAVY RAINFALL...FREQUENT LIGHTNING STRIKES...AND GUSTY
WINDS.

HEAT INDEX READINGS BETWEEN 100 AND 105 DEGREES ARE EXPECTED
DURING THE AFTERNOON EACH DAY THIS WEEK. THIS MAY PRODUCE HEAT
RELATED IMPACTS TO PEOPLE OUTDOORS...ESPECIALLY IN FLOOD AFFECTED
AREAS.

PLEASE REFER TO FLOOD WARNINGS...ADVISORIES AND STATEMENTS FOR
THE LATEST INFORMATION ON WHEN RIVERS ARE EXPECTED TO FALL BELOW
FLOOD STAGE.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS NOT ANTICIPATED.

CAB

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE NEW ORLEANS LA
436 PM CDT MON AUG 22 2016

LAZ059-060-222200-
UPPER LAFOURCHE-ST. CHARLES-
436 PM CDT MON AUG 22 2016

...A STRONG THUNDERSTORM WILL AFFECT NORTH CENTRAL LAFOURCHE AND
SOUTHWESTERN ST. CHARLES PARISHES...

AT 436 PM CDT...A STRONG THUNDERSTORM WAS LOCATED NEAR RACELAND...OR
15 MILES EAST OF THIBODAUX. THE STORM IS NEARLY STATIONARY.

WINDS IN EXCESS OF 30 MPH ARE POSSIBLE WITH THIS STORM.

LOCATIONS IMPACTED INCLUDE...
RACELAND...CHACKBAY...DES ALLEMANDS...BAYOU GAUCHE...MATHEWS...
PARADIS...BOUTTE AND SOUTH VACHERIE.

TORRENTIAL RAINFALL IS ALSO OCCURRING WITH THIS STORM...AND MAY CAUSE
LOCALIZED FLOODING. DO NOT DRIVE YOUR VEHICLE THROUGH FLOODED
ROADWAYS.

FREQUENT CLOUD TO GROUND LIGHTNING IS OCCURRING WITH THIS STORM.
LIGHTNING CAN STRIKE 10 MILES AWAY FROM A THUNDERSTORM. SEEK A SAFE
SHELTER INSIDE A BUILDING OR VEHICLE.

LAT...LON 2990 9085 2990 9068 2989 9067 2990 9063
      2988 9061 2989 9059 2989 9036 2971 9034
      2965 9060
TIME...MOT...LOC 2136Z 145DEG 2KT 2977 9057

CAB

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE NEW ORLEANS LA
521 PM CDT MON AUG 22 2016

LAZ046-048>050-222300-
LIVINGSTON-IBERVILLE-EAST BATON ROUGE-ASCENSION-
521 PM CDT MON AUG 22 2016

...A STRONG THUNDERSTORM WILL AFFECT WEST CENTRAL LIVINGSTON...EAST
CENTRAL IBERVILLE...SOUTHWESTERN EAST BATON ROUGE AND NORTHWESTERN
ASCENSION PARISHES...

AT 518 PM CDT...A STRONG THUNDERSTORM WAS LOCATED OVER
WESTMINSTER...OR OVER BATON ROUGE. THE STORM IS NEARLY STATIONARY.

LOCATIONS IMPACTED INCLUDE...
BATON ROUGE...BAKER...DENHAM SPRINGS...OAK HILLS PLACE...
ST. GABRIEL...GREENWELL SPRING...SHENANDOAH...INNISWOLD...
OLD JEFFERSON...PRAIRIEVILLE...MERRYDALE...GARDERE...WESTMINSTER...
BROWNFIELDS...VILLAGE ST. GEORGE AND BATON ROUGE AIRPORT.

TORRENTIAL RAINFALL IS THE MAIN CONCERN AND MAY CAUSE LOCALIZED
FLOODING. DO NOT DRIVE YOUR VEHICLE THROUGH FLOODED ROADWAYS. 1 TO 2
INCHES OF RAINFALL MAY OCCUR IN LESS THAN AN HOUR.

FREQUENT LIGHTNING IS ALSO OCCURRING!

LAT...LON 3061 9098 3026 9088 3021 9105 3047 9120
      3051 9120 3052 9121 3052 9123 3054 9125
      3056 9125 3057 9126
TIME...MOT...LOC 2218Z 170DEG 4KT 3042 9109

CAB

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE NEW ORLEANS LA
538 PM CDT MON AUG 22 2016

LAZ049-050-057-058-222315-
LIVINGSTON-ST. JOHN THE BAPTIST-ASCENSION-ST. JAMES-
538 PM CDT MON AUG 22 2016

...A STRONG THUNDERSTORM WILL AFFECT SOUTH CENTRAL LIVINGSTON...
EASTERN ST. JAMES...ST. JOHN THE BAPTIST AND EAST CENTRAL ASCENSION
PARISHES...

AT 537 PM CDT...A STRONG THUNDERSTORM WAS LOCATED OVER GARYVILLE...OR
NEAR RESERVE...MOVING NORTH AT 10 MPH.

LOCATIONS IMPACTED INCLUDE...
RESERVE...LAPLACE...GRAMERCY...LUTCHER...NORTH VACHERIE...
GARYVILLE...EDGARD...SOUTH VACHERIE AND WALLACE.

MAIN CONCERN IS TORRENTIAL RAINFALL WHICH IS OCCURRING WITH THIS
STORM...AND MAY CAUSE LOCALIZED FLOODING. DO NOT DRIVE YOUR VEHICLE
THROUGH FLOODED ROADWAYS.

FREQUENT CLOUD TO GROUND LIGHTNING IS OCCURRING WITH THIS STORM.
LIGHTNING CAN STRIKE 10 MILES AWAY FROM A THUNDERSTORM. SEEK A SAFE
SHELTER INSIDE A BUILDING OR VEHICLE.

LAT...LON 3023 9058 3021 9058 3020 9060 3018 9058
      3017 9056 3017 9049 3002 9053 3002 9054
      3000 9054 3000 9055 2997 9054 2992 9055
      2992 9070 3024 9075
TIME...MOT...LOC 2237Z 179DEG 10KT 3006 9064

CAB