Flash Flood Warning 25, NWS New Orleans, LA

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEW ORLEANS/BATON ROUGE LA
325 PM CDT THU JUN 7 2001

...HEAVY RAINFALL EXPECTED TO CONTINUE WITH FLASH FLOOD/FLOOD WATCH
EXTENDED THROUGH FRIDAY...

BREVITY WILL BE THE RULE THIS AFTERNOON AS RECORD RAINFALL TOTALS
CONTINUE TO BUILD ACROSS SOUTHERN MISSISSIPPI AND SOUTHEASTERN
LOUISIANA. THE AVN 310K ISENTROPIC CHART/CONDITIONAL PRESSURE
DIFFERENTIAL AND 200 MB JET FORECAST CHARTS HAVE PERFORMED VERY WELL
FOR THE PAST TWO DAYS IN DEPICTING THE AREAS OF HEAVY RAINFALL AND
WILL GO WITH THIS COMBO AGAIN. HAVE USED THE 30-50MB OF LIFT
REQUIRED AREAS FROM THE CONDITIONAL PRESSURE DIFFERENTIAL CHART AS
THE DEMARCATION OF 70 PERCENT OR GREATER POPS. ADDITIONALLY WITH THE
SUPER SATURATED AIRMASS HAVE ALSO USED THESE AREAS AS THE FOCUS
LOCATION FOR HEAVY RAINFALL. THE 250 MB JET FORECAST SHOWS WANING
SUPPORT FRI NIGHT BUT THEN THE SUPPORT REBOUNDS QUICKLY WITH AN AREA
OF 250 MB DIFFLUENCE AND 500/700MB VORTICITY MAX PHASING TOGETHER AT
18Z SATURDAY. ADDITIONALLY THE CWA FALLS UNDER WEAK BUT TRICKY
NORTHWEST FLOW ON SATURDAY WHICH HOLDS THROUGH THURSDAY. WILL KEEP
RAINFALL CHANCES FROM 50 PERCENT TO 80 PERCENT THROUGH SATURDAY AND
CHANCE CATEGORY THROUGH EXTENDED FORECAST.

KMCB 70/84/69/86 8657   KBTR 72/84/70/86 8657
KMSY 74/85/74/87 8657   KGPT 72/85/72/84 8867

.NEW...NONE.
LA...FLOOD WATCH LAZ034>040-046>050-056>070.
MS...FLOOD WATCH MSZ068>071-077-080.

13

LAZ034>040-046>050-056>070-MSZ068>071-077-080>082-081200-

HAZARDOUS WEATHER OUTLOOK...UPDATED
NATIONAL WEATHER SERVICE NEW ORLEANS LA
1000 AM CDT THU JUN 7 2001

.SYNOPSIS...THE REMNANTS OF TROPICAL STORM ALLISON ARE EXPECTED TO
DRIFT SOUTHWEST OVER SOUTHEAST TEXAS TONIGHT. DEEP TROPICAL MOISTURE
AND UPPER LEVEL DISTURBANCES MOVING NORTH OUT OF THE GULF OF MEXICO
WILL CONTINUE TO BRING SCATTERED AREAS OF HEAVY RAIN ACROSS MUCH OF
THE CENTRAL GULF COAST REGION THROUGH TONIGHT.

.THUNDERSTORMS...
THERE IS A GENERAL THREAT FOR THUNDERSTORMS FOR THE REMAINDER OF
TONIGHT. VERY HEAVY RAINFALL...OCCASIONAL CLOUD TO GROUND LIGHTNING
STRIKES AND WIND GUSTS UP TO 25 MILES AN HOUR WILL BE THE MAIN
THREAT.

.HEAVY RAIN AND FLOODING...
PERIODIC HEAVY RAIN WILL OCCUR ACROSS THE ENTIRE AREA AFTER MIDNIGHT.
A FEW OF THE HEAVY RAIN AREAS WILL BECOME STATIONARY...CAUSING
RAINFALL RATES OF 2 TO 3 INCHES PER HOUR. ADDITIONAL RAINFALL AMOUNTS
OF 4 INCHES WILL BE POSSIBLE THROUGH TONIGHT WITH LESSER AMOUNTS
EXPECTED ALONG THE MISSISSIPPI COAST EAST OF GULFPORT. ANY ADDITIONAL
HEAVY RAIN ON SATURATED GROUND WILL LIKELY CAUSE FLOODING.

.ACTIONS...REFER TO THE LATEST FLOOD RELATED WATCHES...WARNINGS AND
STATEMENTS. THE ACTIVATION OF STORM SPOTTERS MAY BE NEEDED IF
ORGANIZED THUNDERSTORM DEVELOPMENT IS OBSERVED.

FOR MORE INFORMATION PLEASE VISIT OUR HOME PAGE ON THE INTERNET AT
THE FOLLOWING ADDRESS...HTTP://WWW.SRH.NOAA.GOV/LIX (ALL LETTERS
SHOULD BE LOWER CASE).