000
FXUS64 KLIX 272125
AFDLIX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEW ORLEANS LA
325 PM CST MON DEC 27 2010
.SYNOPSIS...
HIGH PRESSURE CENTERED OVER THE LOWER MISSISSIPPI RIVER VALLEY AT
MID AFTERNOON. CLEAR SKIES AND MUCH BELOW NORMAL TEMPERATURES ARE
THE RULE ACROSS THE AREA. CURRENT TEMPERATURES GENERALLY IN THE
MIDDLE 40S...EXCEPT NEAR 40 AT LAKEFRONT AIRPORT AND
BOOTHVILLE...DUE TO LAND HEATING BETTER THAN WATER. DEW POINTS
GENERALLY IN THE LOWER 20S.
&&
.SHORT TERM...
HIGH PRESSURE SLIDES OFF TO THE EAST OVER THE NEXT 48
HOURS...ALLOWING AN ONHSORE WIND COMPONENT TO BEGIN...MODERATING
TEMPERATURES. MOISTURE WILL GRADUALLY RETURN TO THE AREA ON
WEDNESDAY. A SHORTWAVE WILL MOVE ACROSS THE AREA WEDNESDAY
AFTERNOON AND WEDNESDAY NIGHT...PRODUCING A GOOD CHANCE OF SHOWERS
AND THUNDERSTORMS...MAINLY WEDNESDAY NIGHT. THIS WILL NOT BE A
COLD FRONTAL PASSAGE AND ONSHORE FLOW WILL CONTINUE THURSDAY...AND
WILL HOLD SMALL POPS IN THE FORECAST.
ONE LAST COLD NIGHT TONIGHT. TEMPERATURES WILL DROP OFF RAPIDLY
AFTER SUNSET TONIGHT. CURRENT DEWPOINTS SUPPORT LOWS NEAR LAST
NIGHTS LEVELS...MAYBE A DEGREE OR TWO WARMER. THIS STILL SUPPORTS
HARD FREEZE/FREEZE CRITERIA AND WILL UPGRADE WATCHES TO WARNINGS.
THIS WILL BE THE LAST SUBFREEZING NIGHT OF THIS SPELL.
TEMPERATURES WILL MODERATE TO NEAR SEASONAL LEVELS ON
TUESDAY...AND ABOVE NORMAL FOR WEDNESDAY AND THURSDAY...WITH MOST
AREAS CLIMBING ABOVE 70 DEGREES. 35
&&
.LONG TERM...
MEDIUM RANGE MODELS COMING INTO SOMEWHAT BETTER AGREEMENT FOR
WEEKEND SCENARIO. UPPER SYSTEM OVER 4 CORNERS AREA THURSDAY WILL
LIFT NORTHEAST THROUGH THE NORTHERN PLAINS TO LAKE SUPERIOR BY
SATURDAY. ECMWF IS SLIGHTLY SLOWER WITH SCENARIO...BUT PRETTY
CLOSE ON PATH. SURFACE LOW AND BEST FORCING WILL BE NORTH OF THE
AREA...BUT WILL NEED TO MONITOR THINGS AS GFS FORECAST SOUNDINGS
INDICATE CAPES AROUND 1000-1500 AND LIFTED INDICES AROUND -5. BEST
TIME FOR CONVECTION APPEARS CENTERED ON FRIDAY NIGHT AND SATURDAY
MORNING. UPPER SYSTEM SHOULD DRAG FAR ENOUGH EAST OF THE AREA TO
ALLOW US TO DRY OUT FOR SUNDAY AND MONDAY.
TEMPERATURES AHEAD OF THE FRONT WILL BE MUCH ABOVE NORMAL ON
FRIDAY. LOOKING AT 15-20 DEGREES OF COOLING BEHIND THE FRONT...AND
VERIFICATION OF SATURDAY HIGHS WILL BE DEPENDENT ON EXACT
PLACEMENT OF FRONT SATURDAY MORNING. SUNDAY WILL BE SLIGHTLY BELOW
NORMAL WITH TEMPERATURES MODERATING MONDAY AS BOUNDARY BEGINS
RETURNING TO THE NORTH. 35
&&
.AVIATION...
VFR CONDITIONS TO PREVAIL NEXT 24-30 HOURS ALL TERMINALS AS COLD
DRY AIR REMAINS ENTRENCHED OVER SOUTHEAST LOUISIANA AND SOUTH
MISSISSIPPI.
&&
.MARINE...
AXIS OF SURFACE RIDGE HAS MOVED OVER THE AREA WHICH HAS CAUSED WINDS
TO RELAX. THE RIDGE WILL MOVE SLOWLY EAST OF THE NEXT COUPLE OF DAYS
ALLOWING A WEAK RETURN FLOW TO DEVELOP BY TUESDAY NIGHT. WINDS AND
SEAS WILL INCREASE WEDNESDAY THROUGH SATURDAY AS A SERIES OF UPPER
LEVEL DISTURBANCES MOVES THROUGH THE AREA. THE FIRST DISTURBANCE
WILL MOVE ACROSS THE LOWER MISSISSIPPI VALLEY AND ADJACENT COASTAL
WATERS WEDNESDAY NIGHT. WINDS AND SEAS MAY DECREASE A LITTLE ON
THURSDAY BUT ANOTHER UPPER LEVEL TROUGH WILL BE PASSING THROUGH THE
REGION ON FRIDAY NIGHT AND SATURDAY. THIS WILL CAUSE SOUTHEAST FLOW
TO INCREASE TO 20 KNOTS AND GUSTY WITH SEAS BUILDING 6 TO 9 FEET IN
THE OUTER COASTAL WATERS FROM 20 TO 60 MILES OFF SHORE.
&&
.PRELIMINARY POINT TEMPS/POPS...
MCB 22 57 34 62 / 0 10 10 40
BTR 27 59 40 66 / 0 10 10 40
ASD 23 57 39 63 / 0 0 10 30
MSY 30 57 42 66 / 0 0 10 30
GPT 24 57 38 62 / 0 0 10 20
PQL 23 57 33 63 / 0 0 10 20
&&
.LIX WATCHES/WARNINGS/ADVISORIES...
LA...FREEZE WARNING FROM 9 PM MONDAY TO 9 AM TUESDAY FOR THE
FOLLOWING ZONES: ASSUMPTION...LOWER JEFFERSON...LOWER
LAFOURCHE...LOWER PLAQUEMINES...LOWER ST. BERNARD...LOWER
TERREBONNE...ORLEANS...ST. CHARLES...ST. JAMES...ST. JOHN
THE BAPTIST...UPPER JEFFERSON...UPPER LAFOURCHE...UPPER
PLAQUEMINES...UPPER ST. BERNARD...AND UPPER TERREBONNE.
HARD FREEZE WARNING FROM 9 PM MONDAY TO 9 AM TUESDAY FOR THE
FOLLOWING ZONES: ASCENSION...EAST BATON ROUGE...EAST
FELICIANA...IBERVILLE...LIVINGSTON...POINTE COUPEE...ST.
HELENA...ST. TAMMANY...TANGIPAHOA...WASHINGTON...WEST BATON
ROUGE...AND WEST FELICIANA.
GM...NONE.
MS...HARD FREEZE WARNING FROM 9 PM MONDAY TO 9 AM TUESDAY FOR THE
FOLLOWING ZONES:
AMITE...HANCOCK...HARRISON...JACKSON...PEARL
RIVER...PIKE...WALTHALL...AND WILKINSON.
GM...NONE.
&&
$$
