New Orleans Flood Watch and Discussion

[PTPatrick]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEW ORLEANS/BATON ROUGE LA
345 PM CDT SUN JUN 13 2004

.DISCUSSION...
SEVERAL CONCERNS WITH THIS PACKAGE AS WE WILL TRY TO ADDRESS THE
FLOODING AND COASTAL FLOODING THREATS FOR THE NEXT 48 HOURS AND
MAINTAIN A WATCHFUL EYE OF THE SYSTEM OVER THE GULF. VISIBLE
SATELLITE IMAGERY SHOWED AN UNORGANIZED SYSTEM OVER THE GULF BUT
REVEALED SOME OUTWARD SPREADING HIGHER CLOUDS NORTH OVER SOUTHEAST
LOUISIANA AND SOUTH MISSISSIPPI. RADAR IMAGERY SHOWED A COMBINATION
SEA BREEZE PRODUCED CONVECTION AND SOME AREAS OF RAIN OVER THE
COASTAL WATERS ASSOCIATED WITH THE SYSTEM. SURFACE ANALYSIS SHOWED
AN INVERTED TROUGH FROM SOUTHWEST GULF TO THE NORTH CENTRAL GULF
WITH A HIGH BROAD PRESSURE OVER THE NORTHEAST GULF. AT THIS
TIME...THERE IS A GREAT DEAL OF UNCERTAINTY WITH THIS SYSTEM'S SPEED
AND POSSIBLE INTENSIFICATION. HOWEVER...PRECIPITABLE WATER VALUES
ARE EXPECTED TO INCREASE FROM 1.5 INCHES TO NEAR 2.2
INCHES...ESPECIALLY ALONG THE COASTAL AREAS. SHORT RANGE MODELS HAD
SOME PROBLEMS INITIALIZING THE LOW OVER SOUTHWEST GULF. SHORT WAVE
OKLAHOMA AND NORTH TEXAS ON GFS...NGM AND ETA BECOMES CLOSED OFF BUT
MAINTAIN THE COLD CORE AND SETTLES OVER SOUTH TEXAS BY TUESDAY
MORNING. THE UPPER LEVEL ASSOCIATED WITH THE SYSTEM OVER SOUTHWEST
GULF ROTATES NORTH ACROSS THE LOUISIANA COAST MONDAY. ECMWF...NOGAPS
AND UKMET ARE SHOWING A SIMILAR PATTERN. IN ANY EVENT...FORECAST
AREA WILL BE EAST OF THE SYSTEM(S) THROUGH TUESDAY AND MAYBE INTO
WEDNESDAY. WITH AMOUNT OF MOISTURE AVAILABLE...ROUNDS AND ROUNDS OF
SHOWERS AND THUNDERSTORMS MAY CAUSE FLOODING AND CAN NOT PIN POINT
WHICH AREA MAY RECEIVE THE BULK OF THE RAIN. WITH RAIN CHANCES
INCREASING TONIGHT AND GREATER THAN 50 PERCENT THROUGH TUESDAY WILL
ISSUE AN FFA THROUGH TUESDAY AND ISOLATED AMOUNT UP TO 8 INCHES
THROUGH TUESDAY FOR NOW. LATER SHIFTS MAY ADD COUNTIES/PARISHES TO
FFA. WILL MAINTAIN SLIGHTLY HIGH THAN NORMAL POPS WEDNESDAY. UPPER
LEVEL HIGH TO THE EAST WILL REBUILD OVER THE CENTRAL GULF COAST
REGION THURSDAY KNOCKING POPS DOWN TO NORMAL.

SOUTHEAST SURFACE WINDS OVER THE COASTAL WATERS OF 20 TO 25 KNOTS
TONIGHT THROUGH TUESDAY MAY CAUSE TIDES TO INCREASE 2 FEET ABOVE
NORMAL. WILL ISSUE A COASTAL FLOOD STATEMENT AND KEEP A WATCHFUL EYE
IF COASTAL FLOODING BECOMES AN ISSUE.

&&

THE FLOOD WATCH IS IN EFFECT THROUGH TUESDAY FOR PORTIONS
OF EAST CENTRAL LOUISIANA NORTH OF LAKE PONCHARTRAIN...
SOUTHEAST LOUISIANA SOUTH OF LAKE PONTCHARTRAIN AND EXTREME
SOUTH MISSISSIPPI...

THE FLOOD WATCH IS IN EFFECT FOR THE FOLLOWING PARISHES IN
LOUISIANA...

WASHINGTON...SAINT TAMMANY...ORLEANS...JEFFERSON...
TANGIPAHOA...PLAQUEMINES...SAINT CHARLES AND SAINT BERNARD

AND THE FOLLOWING COUNTIES IN EXTREME SOUTH MISSISSIPPI...

PEARL RIVER...HANCOCK...HARRISON...WALTHALL...PIKE
AND JACKSON.

A WEAK AND BROAD LOW LEVEL CIRCULATION OVER THE WESTERN GULF OF
MEXICO...ALONG WITH A LARGE AREA OF DISTURBED WEATHER DISPLACED WELL
TO ITS EAST...IS EXPECTED TO MOVE NORTH TOWARD SOUTHEAST LOUISIANA
AND MISSISSIPPI COAST TONIGHT. A SURGE OF DEEP TROPICAL MOISTURE
WILL MOVE IN AND REMAIN IN PLACE ACROSS THE WATCH AREA TONIGHT
THROUGH TUESDAY. DUE TO THE ANTICIPATED MOVEMENT OF THE
SYSTEM...TRAINING OF SHOWERS AND THUNDERSTORM WILL CREATE A HIGH
RAINFALL EFFICIENCY FOR AREAS AROUND AND EAST OF LAKE PONTCHARTRAIN
AND THE MISSISSIPPI.

RAINFALL TOTALS OF 2 TO 4 INCHES CAN BE EXPECTED ACROSS EAST CENTRAL
LOUISIANA AND SOUTHEAST LOUISIANA WITH ISOLATED AMOUNTS APPROACHING 4
TO 4 INCHES THROUGH TUESDAY. RAINFALL TOTALS OF 3 TO 5
INCHES CAN BE EXPECTED ACROSS EXTREME SOUTH MISSISSIPPI WITH ISOLATED
AMOUNTS APPROACHING 8 INCHES THROUGH TUESDAY.

A FLOOD WATCH MEANS CONDITIONS ARE FAVORABLE FOR HEAVY RAINS AND
SUBSEQUENT FLOODING THAT MAY AFFECT HOMES AND BUSINESSES.
PREPARATIONS SHOULD BE TAKEN OR MAINTAINED TO PROTECT PROPERTY FROM
POTENTIAL FLOODING. IF FLOODING DOES DEVELOP...DO NOT DRIVE INTO
WATER COVERED AREAS.

STAY TUNED TO NOAA WEATHER RADIO...COMMERCIAL RADIO OR TELEVISION
STATIONS...OR YOUR CABLE TELEVISION PROVIDER FOR FURTHER DETAILS OR
UPDATES CONCERNING THIS POTENTIAL FLOOD SITUATION.