Damaging Wind in Louisiana, January 19, 2001

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEW ORLEANS/BATON ROUGE LA
345 AM CST FRI JAN 19 2001

THREAT OF BOTH FLASH FLOODING AND SEVERE THUNDERSTORMS IS DECREASING
AT THE MOMENT...BUT WILL STILL WARRANT KEEPING LINGERING HEADLINES
FOR AT LEAST 2-3 MORE HOURS. OF PARTICULAR INTEREST...A SECONDARY JET
MAX LIFTING NE OVER NE MEXICO AND E OF THE LOWER TX COAST APPEARS TO
BE PROVIDING A SURGE OF UVV AS EVIDENT BY THE INTENSIFYING
CONVECTIVE LINE IN THE COLD SECTOR FROM W OF KBTR NORTHWARD JUST E
OF THE MS RIVER. CHECKING SURFACE REPORTS...AN AWOS STATION AT
HAMMOND LA RECENTLY HAD A COLD FRONTAL PASSAGE...SO THE RUC/MESOETA
FORECAST OF THE FRONT NEAR A SLIDELL/EAST NEW ORLEANS LINE AT 6 AM
LOOKS ABOUT RIGHT. CURRENT THINKING IS THE LINE OF CONVECTION IN OUR
EXTREME NW FORECAST AREA WILL HAVE A HARD TIME CATCHING UP TO THE
WARM SECTOR...BUT THERE MAY BE A SLIGHT POTENTIAL FOR HAIL IF MID
LEVEL COLD AIR ADVECTION IS STRONG ENOUGH WITH THE APPROACHING
TROUGH. DEVELOPING SHOWERS JUST W OF THE TIDAL LAKES BETWEEN KBTR
AND KASD ARE MUCH CLOSER TO THE WARM SECTOR...SO WILL KEEP A CLOSE
WATCH ON THIS ACTIVITY.

WITH THE SYSTEM ACCELERATING THIS MORNING...THE THREAT OF FLASH
FLOODING WILL MAINLY BE IN THE EARLY MORNING HOURS IN THE SAME
PORTION OF E CENTRAL LA AND SW MS AS EARLIER OUTLINED. POINTS EAST
AND SOUTH WILL SEE SOME HEAVY RAIN...BUT THE PROGRESSION OF THE
UPPER SYSTEM SHOULD KEEP ANY ECHO TRAINING BRIEF. SHOWERS AND
THUNDERSTORMS THIS MORNING WILL MOVE EAST BY AFTERNOON WITH
LINGERING RAIN EXPECTED AND GRADUALLY DIMINISHING THROUGH THE
AFTERNOON.

BEYOND THE SHORT TERM...THE UPPER TROUGH OVER TX IS EXPECTED TO
SLOWLY WEAKEN AS IT MOVES ENE ACROSS THE LOWER MS VALLEY LATE TODAY.
A STRONGER NORTHERN STREAM SHORTWAVE TROUGH IS FORECAST TO DROP SE
INTO THE LOWER MS VALLEY TONIGHT PUSHING THE MEAN TROUGH AXIS TO OUR
E SATURDAY MORNING. DRY AIR FROM 850 MB UP WILL SURGE THROUGH MOST
OF THE FORECAST AREA TODAY WITH LINGERING 850 MB MOISTURE NEAR THE
COAST CLEARING OUT EARLY TONIGHT WITH THE TROUGH PASSAGE. BELOW 850
MB IS WHERE THERE IS SOME CONCERN FOR LOW CLOUDS AND SNOW FLURRIES
IN THE COLDER AIR ACROSS OUR N ZONES. AT THIS TIME...IT APPEARS LOW
LEVEL CYCLONIC FLOW AND THE ABSENCE OF STRONG MOISTURE FLUX
DIVERGENCE WILL REMAIN NORTH OF OUR FORECAST AREA FROM NE LA INTO
N/CENTRAL MS...SO WILL LEAVE THE FORECAST DRY IN THE COLDER AIR THIS
EVENING. WILL HOLD ONTO SMALL POPS FOR LINGERING LIGHT RAIN IN THE
EASTERN ZONES THIS EVENING. CONFIDENCE IN CLEARING OF LOW CLOUDS IS
NOT GREAT...BUT WILL WORD FORECAST DECREASING CLOUDINESS LATE
TONIGHT. WILL HOLD TEMPERATURES A BIT ABOVE MOS TONIGHT WITH THE
SLOWER CLEARING AND NW WINDS STAYING UP 10 TO 15 MPH INLAND AND 15
TO 25 MPH AND GUSTY NEAR THE COAST.

STRONG COLD AIR ADVECTION ON SATURDAY SHOULD KEEP DIURNAL RANGES
QUITE LOW...FAVORING THE COLDER MAV HIGHS. WARMER FWC LOWS FOR
SATURDAY NIGHT ARE PREFERRED AT THE MOMENT WITH THE MAV NUMBERS
LOOKING TOO ARCTIC FOR THIS PATTERN. WILL KEEP THE EXTENDED FORECAST
DRY THROUGH TUE AS CURRENTLY WORDED BEFORE THE NEXT UPPER SYSTEM
AFFECTS THE CENTRAL GULF COAST REGION ABOUT WEDNESDAY.

MCB 45/31/42/24 +100  BTR 46/33/43/25 +100
MSY 57/36/46/29 +200  GPT 61/34/45/25 +300

.NEW...SCA FROM KPQL TO THE ATCHAFALAYA RIVER INCLUDING LAKES
PONTCHARTRAIN AND MAUREPAS .
LA...FFA THROUGH 10 AM THIS MORNING 034>037-046>050-056.
MS...FFA THORUGH 10 AM THIS MORNING 068>070.

22