Severe Thunderstorm Warning 39, NWS Lake Charles, LA

SOUTHWEST...CENTRAL LOUISIANA AND SOUTHEAST TEXAS FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LAKE CHARLES LA
804 PM CST FRI MAR 12 1999

850 MB UPPER LEVEL CHART INDICATES JET WITH 35 TO 50 KNOT ALONG
SABINE RIVER THIS EVENING. MOISTURE CONTINUING TO POOL JUST WEST
OF SE TX COUNTY WARNING AREA WITH DEWPOINTS IN THE MID TO UPPER
60S. APPEARS TO BE DECENT LOW LEVEL CONVERGENCE WITH OPPOSING
WINDS MEETING NORTHWEST OF LUFKIN TO NEAR COLLEGE STATION TO
NEAR HONDO TX. SATELLITE AND RADAR INDICATING SUPERCELL DEVELOPMENT
ALONG SOUTHWEST FLANK OF THE CONVERGENCE LINE NEAR A 970 MB SFC
LOW NEAR KCOT. HOUSTON RADAR INDICATED A FEW CELLS DEVELOPING BUT
AT THIS MOMENT JUST IN BEGINNING STAGE. THEIR IS DEFINITELY A CAP
TONIGHT IN OUR CWA AREA BETWEEN 710 MB TO 640 MB. IT MAY TAKE SOME
TIME FOR DEVELOPMENT...BUT ALL THE INGREDIENTS ARE PRESENT FOR
SCATTERED SUPERCELL DEVELOPMENT TO OCCUR IN TORNADO WATCH AREA OVER SE
TX IN THE NEXT FEW HOURS. HEAVY RAIN A THREAT WITH PWS RUNNING
1.50 INCHES. COASTAL FLOOD WATCH LOOKS OK AS SE TO EAST FLOW
CONTINUES AT 15 KNOTS ALONG COASTAL AREA. WILL CONTINUE WITH
CURRENT PACKAGE. 06

BPT TA 067/075 045/060 040 6800
LCH TA 065/075 047/062 040 6800
LFT TA 063/072 050/057 040 3840
AEX TA 057/068 045/055 036 6820

AFTERNOON DISCUSSION 230 PM

BOTH THE MAPS GUIDANCE AND THE LAGRANGIAN TRAJECTORY GUIDANCE
MAXIMIZE THE UPDRAFT POTENTIAL (CAPE) AND THE ROTATIONAL POTENTIAL
(HELICITY) ACROSS THE EASTERN TEXAS COUNTIES BY EARLY TOMORROW
MORNING. THE MAIN DYNAMIC PLAYERS APPEAR TO BE THE BRANCHING CIRRUS-
LEVEL WESTERLIES AND THE EKMAN-LAYER INERTIAL JET (LOW LEVEL JET).
DEEPENING ISALLOBARS ACROSS LOUISIANA TOMORROW MORNING SUGGEST
THAT THIS CONVECTIVE EVENT WILL MARCH EASTWARD UNIMPEDED TROUGH THE
FCST AREA.

FROM A SATELLITE PERSPECTIVE...MY EYES FOCUS-IN ON THE CUT-OFF LOW
CURRENTLY OVER NEW MEXICO. THE MAPS GUIDANCE FORECASTS THIS CUT-OFF TO
TREK EAST-SOUTHEAST AND DEEPEN. A VIGOROUS BAROCLINIC ENERGY
CONVERSION IS ANTICIPATED AS THIS DEEP COLD POOL OF AIR OVER TEXAS
JUXTAPOSES THE DEEP WARM POOL OF AIR ACROSS THE REMAINING SOUTHEAST
UNITED STATES.

WHEN THE FIREWORKS END...THE TROPOPAUSE LEVEL WILL SINK TO THE
500 MB LEVEL...QUITE A TROPOPAUSE FOLD.

AFTER TALKING WITH SLIDELL...WE AGREE THAT A COASTAL FLOOD WATCH WILL
BE IN-EFFECT FOR TONIGHT. EASTERLY WINDS ACROSS THE COASTAL WATERS
ARE AROUND 20 KT. WITH TIDES RUNNING ABOVE NORMAL...SOME PILING-UP
OF THE WATER IS EXPECTED ALONG THE COAST. THE FLASH FLOOD WATCH
REMAINS IN-EFFECT.

21

BPT TA 067/075 045/060 040 6800
LCH TA 065/075 047/062 040 6800
LFT TA 063/072 050/057 040 3840
AEX TA 057/068 045/055 036 6820