FXUS64 KLIX 070154
AFDLIX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEW ORLEANS LA
754 PM CST SUN DEC 6 2009
.UPDATE...
...SOUNDING DISCUSSION...
NO PROBLEMS WITH THE FLIGHT THIS EVENING. MOISTURE BACK ON THE
INCREASE ONCE AGAIN WITH A PW OF 0.78 INCHES. STILL FAIRLY DRY
ABOVE 850 MILLIBARS...HOWEVER AN AREA OF 100 PERCENT HUMIDITY LIES
AROUND 725 MILLIBARS WHERE A BROKEN DECK OF ALTO STRATUS CLOUDS HAS
MOVED IN. WINDS ARE LIGHT FROM SOUTHEAST IN THE LOWER LEVELS AND
MODERATE FROM THE WEST ALOFT.
&&
.PREV DISCUSSION... /ISSUED 349 PM CST SUN DEC 6 2009/
DISCUSSION...
LATEST UPPER AIR ANALYSIS CONTINUE TO SHOW A SLIGHTLY NEGATIVELY
TILTED WAVE OVER SOUTHEAST TEXAS TO NORTHWEST GULF. IR SAT IMAGERY
SOME MID LAYER CLOUD MASS OVER EAST TEXAS...LOUISIANA AND
MISSISSIPPI BUT WARMING HAS BEEN THE TREND THIS AFTERNOON. SURFACE
ANALYSIS SHOWED A SLOW RETREATING HIGH OVER NORTH ALABAMA WITH THE
MAIN HIGH ALONG THE EASTERN SEABOARD. MODEL SOUNDINGS AND PLANER
THATA-E SURFACES FOR TONIGHT THROUGH EARLY MONDAY SHOWED A SLIGHT
DECREASING LAPSE RATES DEVELOPING AHEAD OF THE SHORT WAVE...MAINLY
OVER WEST ZONES LATE TONIGHT. HAVE INSERTED SLIGHT CHANCE OF
THUNDER LATE TONIGHT INTO MONDAY. PASSAGE OF THIS SHORT WAVE WILL
LEAVE RESIDUAL MOISTURE IN PLACE MONDAY. IN ADDITION...THE MAIN
TROUGH OUT WEST WILL DEEPEN ALLOWING THE RIDGE TO AMPLIFY SLIGHTLY
OVER EASTERN CONUS. AS A RESULT...WARM AIR ADVECTION WILL TAKE
PLACE STARTING TONIGHT. MANY AREAS WILL SEE LOW TEMPS THIS EVENING
AND STEADY/RISING TEMPS AFTER MIDNIGHT. MAIN RIDGE WILL CONTINUE
WAA THROUGH MONDAY AND DEEP MOISTURE WILL BE IN PLACE BY MONDAY
NIGHT...PW ABOVE 1.8 INCHES MONDAY NIGHT THROUGH TUESDAY. THUS
RAIN CHANCES INCREASE TO CATEGORICALLY. DISTURBANCE WILL ROTATE
AROUND THE MAIN TROUGH TUESDAY INTO TUESDAY NIGHT...SOMEWHAT
NEGATIVELY TILTED. THIS TIME SURFACE INSTABILITY WILL BE IN PLACE
TUESDAY AND TUESDAY NIGHT. HAVE CONTINUED POSSIBLE SEVERE IN HWO
BUT NOT IN ZONES...BULK OF DYNAMICS SHOULD REMAIN NORTH...SEVERE
THREAT IS SLIGHT TUESDAY AND TUESDAY NIGHT. PACIFIC WAVE WILL
CLEAR THE AREA EARLY WEDNESDAY AND KNOCK TEMPS BACK TO NORMS
THURSDAY AND FRIDAY. NO REAL PUSH WITH THE FRONTAL BOUNDARY SOUTH
INTO THE GULF. A THIRD WAVE WILL PRODUCE A SURFACE INVERTED TROUGH
OVER NORTHWEST GULF WEST LATE FRIDAY AND TRACK EAST. WARM SECTOR
IS NOT EXPECTED OVER THE LAND AREAS LATE FRIDAY INTO SATURDAY.
WILL KEEP RAIN FOR FRIDAY NIGHT THROUGH EARLY SATURDAY.
AVIATION...
SURFACE HIGH PRESSURE WILL MOVE EAST TONIGHT RETURN FLOW TO DEVELOP
LATE TONIGHT. CEILINGS ARE EITHER UNRESTRICTED OR AROUND 10 THOUSAND
FEET. CEILINGS SHOULD LOWER TO 4 TO 5 THOUSAND FEET AFTER MIDNIGHT
WITH A RISK OF PATCHY LIGHT FOG DEVELOPING AFTER MIDNIGHT BECAUSE
EAST WINDS AROUND 10 MPH ARE EXPECTED TONIGHT. SCATTERED SHOWERS
EXPECTED TO MOVE INTO AREA FROM WEST LATE TONIGHT AS THE COLD FRONT
APPROACHES THE AREA FROM THE WEST. SHOWERS SHOULD BECOME MORE
NUMEROUS AS THE FRONT BECOMES STATIONARY ACROSS SOUTHERN MS AND
SOUTHEAST LA ON MONDAY WHICH SHOULD LOWER CEILINGS BETWEEN 1 AND 2
THOUSAND FEET AND VISIBILITY SHOULD BE 3 TO 5 MILES IN RAIN SHOWERS.
COASTAL...
AS THE SURFACE RIDGE MOVES EAST TONIGHT A COLD FRONT WILL APPROACH
FROM THE WEST AND BECOME STATIONARY ON MONDAY. THE FRONT WILL EXTEND
FROM AS A LOW PRESSURE AREA OFF THE TEXAS COAST INTO LA AND MS.
ANOTHER STRONGER LOW PRESSURE AREA WILL DEVELOP IN THE TX PANHANDLE
ON TUESDAY WHICH WILL INCREASE SOUTHERLY FLOW AND SEAS IN THE
COASTAL WATERS. THE COLD FRONT WILL FINALLY MOVE THROUGH THE COASTAL
WATERS TUESDAY NIGHT ALLOWING HIGH PRESSURE TO DOMINATE THE AREA
WEDNESDAY AND THURSDAY. ANOTHER LOW PRESSURE AREA WILL DEVELOP OFF
THE TEXAS COAST AND MOVE THROUGH THE LA AND MS COASTAL WATERS ON
FRIDAY INCREASING EAST AND SOUTHEAST WINDS OF 2O TO 25 KNOTS AND
ROUGH SEAS TO THE COASTAL WATERS.
&&
.PRELIMINARY POINT TEMPS/POPS...
MCB 49 60 55 69 / 40 60 70 80
BTR 54 66 58 74 / 50 60 70 80
MSY 55 69 61 75 / 40 60 70 80
GPT 50 66 58 70 / 20 50 50 80
&&
.LIX WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
GM...NONE.
MS...NONE.
GM...NONE.
&&
$$
