FXUS64 KLCH 270013
AFDLCH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LAKE CHARLES LA
613 PM CST SAT DEC 26 2009
.UPDATE...NEW AVIATION DISCUSSION AVAILABLE.
&&
.AVIATION...CLOUDS FROM 5-7K FEET BLANKET THE AREA THIS EVENING
ASSOCIATED WITH LOW PRESSURE ADVANCING EAST ACROSS THE CENTRAL
GULF. MAIN RAINS WITH THIS SYSTEM WILL REMAIN OFFSHORE BUT COULD
NOT RULE OUT A FEW SPRINKLES ALONG AND SOUTH OF THE INTERSTATE 10
CORRIDOR. CLOUDS/SPRINKLES TO CLEAR OUT WEST TO EAST LATE
TONIGHT/SUNDAY MORNING.
MARCOTTE
&&
.PREV DISCUSSION... /ISSUED 340 PM CST SAT DEC 26 2009/
DISCUSSION...
ANOTHER CHILLY DAY ACROSS THE FORECAST AREA WITH TEMPERATURES
CURRENTLY IN THE LOW TO MID 50S. CLOUDS HAVE STARTED TO THICKEN UP
AGAIN AND LOWER AS SHORT WAVE IN THE ACTIVE SOUTHERN STREAM
APPROACHES THE WESTERN GULF OF MEXICO. LONG RANGE OF KLCH RADAR
DOES SHOW SOME WEAK RETURNS BEGINNING TO SHOW UP OVER THE OUTER
COASTAL WATERS AND TO THE SOUTHWEST. OBSERVATIONS ALONG THE MIDDLE
AND LOWER TEXAS COAST DUE SHOW SOME SPRINKLES REACHING THE GROUND.
LATEST MSAS ANALYSIS ALSO SHOWS A WEAK LOW PRESSURE SYSTEM HAS
FORMED EAST OF KBRO.
THE UPPER LEVEL SHORT WAVE AND SURFACE LOW PRESSURE SYSTEM WILL
MOVE QUICKLY ACROSS THE NORTHERN GULF OF MEXICO TONIGHT. BEST LOW
LEVEL CONVERGENCE AND ISENTROPIC LIFT WITH THE LOW REMAIN WELL
OFFSHORE...AND AIR MASS OVER THE FORECAST AREA REMAINS RELATIVELY
DRY WITH PWAT NEARING ONE INCH OVERNIGHT IN THE COASTAL AREAS.
THEREFORE...ANY RAINFALL TONIGHT SHOULD CONFINED SOUTH OF THE I-10
CORRIDOR AND BE RATHER LIGHT WITH AMOUNTS RANGING FROM A TRACE TO
A LESS THAN ONE TENTH OF AN INCH.
HIGH PRESSURE AND A DRY AIRMASS WILL AGAIN MOVE INTO THE FORECAST
AREA ON SUNDAY BEHIND THE DEPARTING LOW PRESSURE SYSTEM GIVING THE
FORECAST AREA RATHER COOL CONDITIONS.
ON TUESDAY ANOTHER UPPER LEVEL DISTURBANCE MOVES OUT OF THE BAJA
AREA IN THE ACTIVE SOUTHERN STREAM THAT WILL AGAIN INDUCE A
SURFACE LOW TO DEVELOP OFF THE LOWER TEXAS COAST. AT THIS
TIME...SURFACE LOW IS EXPECTED TO BE STRONGER AND FURTHER TO THE
NORTH THAN THE ONE TONIGHT.
THIS LOW PRESSURE SYSTEM WILL MOVE ACROSS THE COASTAL WATERS AND
JUST OFF THE LOUISIANA COAST LATE TUESDAY NIGHT AND THE FIRST PART
OF WEDNESDAY. AS THIS DISTURBANCE WILL BE STRONGER...MOISTURE
SURGE WILL BE HIGHER...WITH PWAT OVER 1 INCH TO AROUND 1.25 INCHES
AND MEAN RH OVER 80 PERCENT. LOW CONVERGENCE AND ISENTROPIC LIFT
AS WELL WILL BE GOOD AND THUS RAIN SHOULD ENTER THE FORECAST
TUESDAY AFTERNOON...BECOMING LIKELY TUESDAY NIGHT...BEFORE
TAPERING OFF WEST TO EAST DURING WEDNESDAY. PROGGS ALSO SHOW SOME
ELEVATED INSTABILITY NEAR THE SURFACE LOW...SO WILL AS SOME
ISOLATED THUNDER FOR THE COASTAL WATERS DURING THAT TIME FRAME.
EXTENDED PROGGS SHOW A BIT OF A PATTERN SHIFT BY THE END OF THE
WEEK WITH A RIDGE BUILDING OUT OF THE PACIFIC AND ALONG THE
WESTERN U.S. THIS WILL ALLOW A DEEP NORTH FLOW TO DEVELOP EAST OF
THE ROCKIES WITH AIR MASS WITH POLAR ORIGINS SPILLING DOWN THE
COUNTRY TO THE GULF COAST. COLD FRONT WITH THE LEADING EDGE OF THE
AIR MASS WILL MOVE ACROSS THE FORECAST AREA ON NEW YEARS EVE WITH
A SLIGHT CHANCE FOR SHOWERS. A DRY AND COLD NEW YEARS DAY INTO
NEXT WEEKEND IS THEN EXPECTED.
RUA
MARINE...
AN UPPER LEVEL DISTURBANCE WILL CARRY A WEAK LOW PRESSURE SYSTEM
ACROSS THE NORTHERN GULF OF MEXICO TONIGHT. THE RESULT WILL BE
SOME LIGHT RAIN DEVELOPING OVER THE COASTAL WATERS WITH A MODERATE
EAST WIND. MODERATE OFFSHORE WINDS WILL THEN DEVELOP BEHIND THE
LOW ON SUNDAY WITH THE POSSIBILITY OF AT-LEAST SMALL CRAFT EXERCISE
CAUTION CRITERIA ON SUNDAY NIGHT INTO MONDAY.
BY TUESDAY...ANOTHER SURFACE LOW IS EXPECTED TO FORM OFF THE TEXAS
COAST AND MOVE ACROSS THE COASTAL WATERS ON TUESDAY NIGHT AND
EARLY WEDNESDAY. THIS LOW PRESSURE SYSTEM IS EXPECTED TO BE A
LITTLE DEEPER WITH A TIGHTER PRESSURE GRADIENT. THUS SMALL CRAFT
ADVISORY CONDITIONS WILL BE LIKELY FOR PORTIONS OF THE COASTAL
WATERS FROM LATE TUESDAY INTO WEDNESDAY. THIS LOW WILL ALSO BRING
RAIN WITH A FEW THUNDERSTORMS.
RUA
&&
.PRELIMINARY POINT TEMPS/POPS...
KLCH 39 57 33 53 34 / 20 10 0 0 10
KBPT 39 57 33 53 36 / 20 10 0 0 10
KAEX 33 54 30 51 30 / 10 10 0 0 10
KLFT 39 56 34 53 32 / 20 10 0 0 10
&&
.LCH WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
TX...NONE.
GM...NONE.
&&
$$
