Severe Thunderstorm Warning 18, NWS Lake Charles, LA

SOUTHEAST TEXAS AND SOUTHWEST LOUISIANA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LAKE CHARLES LA
1020 AM CST SAT MAR 18 2000

SHWRS AND TSTMS OVR THE NW GULF THIS MRNG FOCUSED ALG WARM FRNT
LIFTING NORTHWARD. FRONT WILL MOVE INTO SOUTHERN LA AND EASTERN TX
AS LOW FM THE WEST MOVES INTO CNTRL TX THIS AFTN. THIS WILL ALLOW LOW
LVL INSTABILITY FM THE GULF INTO THE AREA AS MID AND UPR LVL
DYNAMIC'S MOVE INTO NE TX BY THIS AFTN SUPPORTING CONVECTIVE
DEVELOPMENT AND PSBL SQ LINE EARLY THIS EVE. LATEST STLT INDCG LARGE
CLD FIELD OVR THE NW GULF EXTENDING NORTHWARD... ALTHOUGH BREAKS IN
CLDS WILL ALLOW TEMPS TO RECOVER INTO THE UPPER 70S TO NEAR 80 WITH
DEW POINTS CLIMBING INTO THE MID 60S.

MRNG SOUNDING OUT OF LCH HAS HELICITY VALUES AROUND 174 M2/S2...CAPE
ABOUT 700 J/KG AND WET BULB ZERO AT 9500 ASL. PRECIP WATER VALUES
REMAINS LOW AT .83 INCHES BUT THIS SHLD IMPROVE WITH THE INJECTION OF
GULF MSTR. WARM AIR HAS MOVED OFF THE MEXICAN PLATEAU THIS MRNG AND
SHOWING UP NICELY AROUND 750 MB WITH INVERSION EXTENDING THROUGH 700
MB...  WITH ATMOSPHERE DRYING OUT ABV 750 MB. THIS WILL CHANGE
THROUGH THE AFTERNOON HOURS... FM THE WEST AS AMPLITUDE TROF AND
NORTHERN STREAM DIVES DOWN INTO TX. INTERACTION DEVELOPS BETWEEN
NORTHERN AND SOUTHERN STREAMS CREATING STRONG UPPER DIFLUENCE.
BELIEVE THAT THE MAIN THREAT APPEARS TO BE FM DAMAGING WINDS AND
LARGE HAIL.

ETA CONTINUES TO BE THE MDL {OF CHOICE. WILL LET ZONES STAND ATTM.

.LCH...
LA...NONE
TX...NONE

.PRELIM...
BPT 79/62/73/48 5530
LCH 76/64/71/51 5440
LFT 77/61/69/53 5440
AEX 78/58/67/50 6550

KUYPER/RUA

LAZ030-031-041-042-051-TXZ180>182-201-215-216-181800-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE LAKE CHARLES LA
724 AM CST SAT MAR 18 2000

...SEVERE WEATHER POSSIBLE THIS AFTERNOON...
...HEAVY RAINFALL ALSO EXPECTED THROUGH TONIGHT...

THERE IS A RISK OF SEVERE THUNDERSTORMS OVER SOUTHEAST TEXAS AND
SOUTHWEST LOUISIANA THIS AFTERNOON. A LOW PRESSURE SYSTEM IN WEST
TEXAS IS EXPECTED TO MOVE INTO NORTHEAST TEXAS THIS EVENING. THE
AIRMASS AHEAD OF THE THE TRAILING COLD FRONT IS PRIMED WITH MOISTURE
FROM THE GULF OF MEXICO.

IN ADDITION...A VIGOROUS UPPER LEVEL DISTURBANCE WILL INTRODUCE
SUFFICIENT COLDER AIR ALOFT TO CAUSE THE AIRMASS OVER THE REGION TO
BECOME UNSTABLE. THESE CONDITIONS WILL BE FAVORABLE FOR THE FORMATION
OF SQUALL-LINE THUNDERSTORMS WHICH ARE EXPECTED TO MOVE ACROSS THE
AREA THIS AFTERNOON.

AS THESE THUNDERSTORMS APPROACH FROM THE WEST...UPPER LEVEL WINDS
WILL GIVE A SUFFICIENT BOOST FOR A FEW OF THE STORMS TO PRODUCE
LARGE HAIL AND DAMAGING WINDS.

HEAVY RAINS ARE ALSO LIKELY WITH THESE STORMS...WITH BETWEEN A
HALF INCH AND AN INCH OF RAINFALL OVER MOST OF THE AREA THROUGH
TONIGHT. SOME LOCATIONS MAY SEE UPWARDS OF TWO INCHES WHERE
THUNDERSTORMS WITH HEAVY RAINS REPEATEDLY MOVE OVER THE SAME
LOCATIONS. THE RAINFALL SHOULD COME TO AN END ON SUNDAY AS THE
COLD FRONT PUSHES EAST.

ACTIVATION OF STORM SPOTTERS MAY BE REQUIRED THIS AFTERNOON.
RESIDENTS WITH NOAA WEATHER RADIOS SHOULD SET THEIR RADIOS FOR
ALERT AND MONITOR FOR UPDATES.

STAY TUNED TO YOUR LOCAL MEDIA SOURCES AND CABLE TV WEATHER
OUTLETS FOR THE LATEST INFORMATION CONCERNING THESE THUNDERSTORMS.

ADDITIONAL WEATHER INFORMATION CAN ALSO BE OBTAINED THROUGH THE LAKE
CHARLES NATIONAL WEATHER SERVICE WEB SITE AT WWW.SRH.NOAA.GOV/LCH.

SWEENEY

LAZ027>033-041>045-051>055-TXZ180>182-201-215-216-182230-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE LAKE CHARLES LA
1130 AM CST SAT MAR 18 2000

...SEVERE WEATHER POSSIBLE THIS AFTERNOON...
...HEAVY RAINFALL ALSO EXPECTED THROUGH TONIGHT...

THERE IS A RISK OF SEVERE THUNDERSTORMS OVER SOUTHEAST TEXAS AND
SOUTHWEST LOUISIANA THIS AFTERNOON...IN ADVANCE OF A COLD FRONT
THAT WILL PUSH INTO EASTERN TEXAS. LOW LEVEL MOISTURE FROM THE GULF
COMBINED WITH A VIGOROUS UPPER LEVEL DISTURBANCE...WILL INTRODUCE
SUFFICIENT COLDER AIR ALOFT TO CAUSE THE AIRMASS OVER THE REGION TO
BECOME VERY UNSTABLE. THESE CONDITIONS WILL BE FAVORABLE FOR THE
FORMATION OF SQUALL-LINE THUNDERSTORM DEVELOPMENT.

AS THESE STORMS DEVELOP SOME STORMS WILL BECOME SEVERE. THE
GREATEST THREAT FROM STORMS TODAY WILL BE FROM LARGE HAIL AND
DAMAGING WINDS.

HEAVY RAINS ARE ALSO LIKELY WITH THESE STORMS...WITH BETWEEN ONE TO
THREE INCHES POSSIBLE. SOME LOCATIONS MAY SEE UPWARDS OF FOUR TO
FIVE INCHES IN HEAVIER STORMS...AS THEY REPEATEDLY AFFECT THE SAME
LOCATION. RAINFALL ACTIVITY WILL TAPER THROUGH THE EARLY MORNING
HOURS AS A COLD FRONT WILL MOVE INTO THE AREA LATE SUNDAY MORNING.

ACTIVATION OF STORM SPOTTERS MAY BE REQUIRED THIS AFTERNOON.
RESIDENTS WITH NOAA WEATHER RADIOS SHOULD SET THEIR RADIOS FOR
ALERT AND MONITOR FOR UPDATES.

STAY TUNED TO YOUR LOCAL MEDIA SOURCES AND CABLE TV WEATHER
OUTLETS FOR THE LATEST INFORMATION CONCERNING THESE THUNDERSTORMS.

ADDITIONAL WEATHER INFORMATION CAN ALSO BE OBTAINED THROUGH THE LAKE
CHARLES NATIONAL WEATHER SERVICE WEB SITE AT WWW.SRH.NOAA.GOV/LCH.

K. KUYPER