Severe Thunderstorm Warning 2, NWS Lake Charles, LA

SOUTHEAST TEXAS..SOUTHWEST AND CENTRAL LOUISIANA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LAKE CHARLES LA
225 AM CST TUE JAN 6 1998

A POTENTIALLY DANGEROUS FLOOD SITUATION SETTING UP ACROSS THE FA
TODAY AS HEAVY RAINS WILL FALL ON ALREADY SATURATED GROUNDS...
INCLUDING SWOLLEN RIVERS...DITCHES...AND STREAMS. THUS...WILL
NEED TO CONTINUE FLASH FLOOD WATCH FOR ENTIRE CWA.

LATEST WATER VAPOR IMAGERY SHOWING NEXT SHORT WAVE TROF APROACHING
FROM EAST TEXAS WITH WEAK ECHO RETURNS DEVELOPING ACROSS THE SE TX
ZONES. A SECOND AREA OF INTEREST IS THE INTENSE CONVECTION IN THE
LA CSTL WATERS SOUTH OF THE VERMILION BAY. THIS ACTIVITY APPEARS TO
BE ASSOCIATED WITH AN AREA OF PRONOUNCED UPPER DIVERGENCE BETWEEN THE
SUB TROP JET OVER THE GULF OF MEX AND THE UPPER TROF OVER THE SRN
PLAINS.  THIS AREA WILL MAINLY IMPACT SE PORTIONS OF THE CWA...ST
MARY AND ST MARTIN PARISHES.  PRIMARY FOCUS WILL NEED TO BE PLACED
ON DEVELOPING CONVECTION IN THE SE TX ZONES WHICH WILL PROGRESS
EASTWARD INTO THE WRN LA ZONES IN THE NEXT COUPLE OF HOURS.

MAIN INGREDIENTS COMING INTO PLAY WILL BE THE SLOW EASTWARD MOVEMENT
OF THE SFC TROF AND PARALLEL FLOW ALOFT...ALLOWING FOR TRAINING OF
SHOWERS AND THUNDERSTORMS. IN ADDITION...MODELS SUGGEST A DYNAMIC
COUPLING OF THE JET AXES OF THE SUB TROP JET AND SOUTHERN BRANCH.
IF THIS WERE TO COME TO FRUITION...VERY INTENSE RAINS COULD BE
EXPECTED TO CARRY ON INTO THE OVERNIGHT. QPF AMOUNTS OF 2 TO 4 INCHES
SEEM REASONABLE ACROSS THE REGION WITH THE HEAVIEST RAINFALL ORIENTED
ALONG THE THE SRN ZONES WHERE THE HIGHEST PWS AND THETA-E VALUES WILL
BE PRESENT.  THE COMBINATION OF DIFFLUENCE ALOFT AND STRONG
UNIDIRECTIONAL WINDS MAY RESULT IN SOME BOW-LIKE FEATURES...BUT FOR
NOW WOULD LIKE TO PLACE EMPHASIS ON THE HEAVY RAINFALL.

THE SFC FRONT WILL MOVE THROUGH SOMETIME ON WED WITH OVERRUNING
CLOUDS AND SHOWERS CONTINUING THROUGH MUCH OF THE DAY.

AS FOR TEMPS...NGM MOS LOOKS REASONABLE WITH ONLY MINOR TWEAKING.

5

BPT 70/63/65 +86
LCH 70/63/65 +86  LFT 70/65/67 887  AEX 69/62/64 887

LAZ027>033-041>045-051>055-TXZ180>182-201-215-216-062100-

HEAVY RAINFALL AND SEVERE WEATHER OUTLOOK
NATIONAL WEATHER SERVICE LAKE CHARLES LA
435 AM CST TUE JAN 6 1998

THE THREAT OF HEAVY RAINFALL WILL CONTINUE THROUGH WEDNESDAY FOR ALL
OF SOUTHEAST TEXAS...AND FOR SOUTHWEST...CENTRAL AND SOUTH CENTRAL
LOUISIANA. DUE TO THE ALREADY SATURATED GROUNDS AND SWOLLEN RIVERS...
CREEKS...AND DITCHES FROM THE RECENT HEAVY RAINFALL...A FLASH FLOOD
WATCH IS IN EFFECT FOR THE ABOVE MENTIONED AREAS.

THE INGREDIENTS COMING TOGETHER FOR THE HEAVY RAINFALL EVENT INCLUDE
A VERY MOIST TROPICAL AIRMASS...AN ACTIVE UPPER LEVEL JET...AND A
SLOW MOVING COLD FRONT APPROACHING FROM EAST TEXAS. WINDS AT BOTH THE
SURFACE AND ALOFT WILL BE FROM THE SOUTH ALLOWING THUNDERSTORMS TO
TRAIN OVER THE SAME AREA FOR SEVERAL HOURS CREATING THE POTENTIAL FOR
SIGNIFICANT FLOODING.

FURTHER COMPLICATING THE SITUATION ARE THE ALREADY SATURATED GROUNDS
FROM THE SUNDAY NIGHT AND MONDAY MORNING RAINFALL EVENT WHICH
PRODUCED SEVERAL INCHES OF RAIN ACROSS THE FORECAST AREA. THE
HEAVIEST RAINFALL OCCURRED ACROSS SOUTH CENTRAL LOUISIANA WHERE
4 TO 7 INCHES WAS REPORTED BY NATIONAL WEATHER SERVICE COOPERATIVE
OBSERVERS AND DOPPLER RADAR. THIS CAUSED THE VERMILION RIVER IN
LAFAYETTE LOUISIANA TO RISE TO ABOVE FLOOD STAGE RESULTING IN THE
FLOODING OF SOME HOMES...WHILE ADDITIONAL FLASH FLOODING OF LOW-LYING
AREAS OCCURRED DUE TO RAPID RAINFALL RUNOFF.

RAINFALL TOTALS OF 2 TO 4 INCHES ARE EXPECTED BY WEDNESDAY MORNING
WITH ISOLATED AMOUNTS OF UP TO 6 INCHES POSSIBLE. SPECIAL EMPHASIS
IS PLACED ON THOSE RESIDENTS ALONG THE VERMILION RIVER WHERE
THE POTENTIAL FOR SERIOUS FLOODING EXISTS SHOULD HEAVY RAINS ONCE
AGAIN DEVELOP.

THERE IS ALSO A THREAT FOR SEVERE WEATHER AS THE COLD FRONT
APPROACHES TONIGHT. THE MAIN THREAT WILL BE LARGE HAIL AND DAMAGING
WINDS.

STAY TUNED TO NOAA WEATHER RADIO OR YOUR FAVORITE MEDIA SOURCE
FOR UPDATES ON THIS POTENTIALLY DANGEROUS WEATHER SITUATION.

LAZ027>033-041>045-051>055-TXZ180>182-201-215-216-062100-

HEAVY RAINFALL AND SEVERE WEATHER OUTLOOK
NATIONAL WEATHER SERVICE LAKE CHARLES LA
435 AM CST TUE JAN 6 1998

THE THREAT OF HEAVY RAINFALL WILL CONTINUE THROUGH WEDNESDAY FOR ALL
OF SOUTHEAST TEXAS...AND FOR SOUTHWEST...CENTRAL AND SOUTH CENTRAL
LOUISIANA. DUE TO THE ALREADY SATURATED GROUNDS AND SWOLLEN RIVERS...
CREEKS...AND DITCHES FROM THE RECENT HEAVY RAINFALL...A FLASH FLOOD
WATCH IS IN EFFECT FOR THE ABOVE MENTIONED AREAS.

THE INGREDIENTS COMING TOGETHER FOR THE HEAVY RAINFALL EVENT INCLUDE
A VERY MOIST TROPICAL AIRMASS...AN ACTIVE UPPER LEVEL JET...AND A
SLOW MOVING COLD FRONT APPROACHING FROM EAST TEXAS. WINDS AT BOTH THE
SURFACE AND ALOFT WILL BE FROM THE SOUTH ALLOWING THUNDERSTORMS TO
TRAIN OVER THE SAME AREA FOR SEVERAL HOURS CREATING THE POTENTIAL FOR
SIGNIFICANT FLOODING.

FURTHER COMPLICATING THE SITUATION ARE THE ALREADY SATURATED GROUNDS
FROM THE SUNDAY NIGHT AND MONDAY MORNING RAINFALL EVENT WHICH
PRODUCED SEVERAL INCHES OF RAIN ACROSS THE FORECAST AREA. THE
HEAVIEST RAINFALL OCCURRED ACROSS SOUTH CENTRAL LOUISIANA WHERE
4 TO 7 INCHES WAS REPORTED BY NATIONAL WEATHER SERVICE COOPERATIVE
OBSERVERS AND DOPPLER RADAR. THIS CAUSED THE VERMILION RIVER IN
LAFAYETTE LOUISIANA TO RISE TO ABOVE FLOOD STAGE RESULTING IN THE
FLOODING OF SOME HOMES...WHILE ADDITIONAL FLASH FLOODING OF LOW-LYING
AREAS OCCURRED DUE TO RAPID RAINFALL RUNOFF.

RAINFALL TOTALS OF 2 TO 4 INCHES ARE EXPECTED BY WEDNESDAY MORNING
WITH ISOLATED AMOUNTS OF UP TO 6 INCHES POSSIBLE. SPECIAL EMPHASIS
IS PLACED ON THOSE RESIDENTS ALONG THE VERMILION RIVER WHERE
THE POTENTIAL FOR SERIOUS FLOODING EXISTS SHOULD HEAVY RAINS ONCE
AGAIN DEVELOP.

THERE IS ALSO A THREAT FOR SEVERE WEATHER AS THE COLD FRONT
APPROACHES TONIGHT. THE MAIN THREAT WILL BE LARGE HAIL AND DAMAGING
WINDS.

STAY TUNED TO NOAA WEATHER RADIO OR YOUR FAVORITE MEDIA SOURCE
FOR UPDATES ON THIS POTENTIALLY DANGEROUS WEATHER SITUATION.