FXUS64 KLIX 222156
AFDLIX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEW ORLEANS LA
356 PM CST TUE DEC 22 2009
.SHORT TERM...
SYNOPTIC FLOW BEGINNING TO RESPOND TO THE STRENGTHENING PRESSURE
GRADIENT OUT WEST. WIND SPEEDS SHOULD CONTINUE TO BE ELEVATED
THROUGH THE NIGHT KEEPING ANY CHANCE OF FOG AT BAY. WINDS WILL
CONTINUE TO ALSO BRING AN ABUNDANCE OF MOISTURE BACK TO THE AREA
FROM THE DEEP GULF. MOISTURE LOADING IS ALREADY OCCURRING OVER
EAST TX WHERE SH/TS ARE BREAKING OUT. ONLY LIGHT SHOWERS EXPECTED
FOR THE NORTHERN MOST TIER OF OUR AREA TONIGHT AND A GOOD PORTION
OF WED. THE MAIN TS AREAS WILL WAIT UNTIL THERE IS ENOUGH SUPPORT
UPSTAIRS TO GET STARTED. NICE 30H DIVERGENT SLOT MOVES ACROSS A
WARM FRONT THAT MANAGES TO MOVE TO NEAR THE MISS/LA EAST WEST
BORDER BY EARLY THU MORNING. THE WARM FRONT WILL BECOME A FOCUS
FOR TS ACTIVITY BUT MORESO HELPING THESE TS GET CONNECTED WITH
THIS SPLIT FLOW ALOFT FROM LFT TO BTR TO MCB. THE SLOWER MOVEMENT OF
THE WARM FRONT COULD CAUSE SOME HEAVIER PRECIP AMOUNTS AS WELL.
THIS ALL STARTS OUT AROUND MIDNIGHT WED NIGHT ALONG THE WARM FRONT
THAT WILL BE LOCATED FROM LFT TO SLIDELL TO NEAR MOBILE THEN OUT
INTO THE GULF. SHOWERS SHOULD BE THE MAIN FEATURE ALONG THE WARM
FRONT EAST OF THE LFT TO BTR AREA. BUT WHERE THE CONVECTION IS
ABLE TO TAP THE BETTER DYNAMICS ALOFT...THERE WILL BE A FEW THAT
COULD BECOME SEVERE. AS THE WARM FRONT MOVES NORTH WE SHOULD SEE
THE TS BECOME STRONGER AS IT APPROACHES THE MISS STATE LINE. NOW
FOR THE COLD FRONT AND ASSOCIATED SQUALL LINE.
A STRONG 50-55KT JET JUST ABOVE THE BOUNDARY LAYER WILL EXIST AND
THIS WILL GET CAUGHT UP IN SEVERAL TS DOWNBURSTS. DRY AIR WILL
QUICKLY MOVE IN BEHIND THIS SQUALL LINE FORCING IT EAST QUICKLY.
THE SPEED OF THE LINE...NEG BUOYANCY DUE TO DRY AIR INTRUSION AND RAIN
SHAFTS CAUSING THE 50KT JET TO DIVE TO THE SFC WILL CAUSE SEVERAL
IF NOT MANY TS TO BOW ALONG THE MAIN LINE. QUITE SIMPLY...THERE
SHOULD BE A VERY GOOD POTENTIAL TO SEE MANY SEVERE TS WITH STRAIGHT
LINE WIND DAMAGE. TORNADIC POTENTIAL WILL ALSO BE PRESENT. AS
STRONG SE WINDS FALL INTO THE VERY WEAK WIND SPEEDS OF THE TROUGH
AXIS...IT WILL CAUSE NUMEROUS MICROSCALE VORTICIES. THESE SMALL
SPINUPS WILL GET ADVECTED NORTHWARD ALONG THE SQUALL LINE WITH THE
MAIN SYNOPTIC FLOW(SOLENOIDAL ADVECTION). WHEN THESE AREAS FALL
INTO A LARGER BOWING SEGMENT...THEY CAN ADD TO THE STRENGTH OF THE
VORT CENTER LOCATED ON EITHER END OF THE BOW AND MAY CAUSE A
TEMPORARY SPINUP CREATING A TORNADO. ALL THAT SAID TO SIMPLY SAY THERE
WILL BE THE POSSIBILITY OF TORNADOES AHEAD AND ALONG THE MAIN LINE
OF TS.
.LONG TERM...
ONCE THE COLD FRONT MOVES THROUGH...SOME VERY COLD AIR WILL BEGIN
TO MOVE INTO THE AREA. TEMPS SHOULD STRUGGLE TO REACH 50 IN MANY
AREAS FRI AND SAT. ANOTHER IN A LINE OF SEVERAL GULF LOWS WILL
BEGIN TO AFFECT THE AREA BY NEXT WEEKEND. WITH TWO MORE SYSTEMS
SLATED FOR THE AREA BEFORE THE END OF THE YEAR...WE SHOULD EASILY
BEAT THE ALL TIME WETTEST MONTH ON RECORD AT MSY SINCE WE ONLY
NEED ABOUT .18" OF RAIN FOR THE SITE..SHORT TERM...
&&
AVIATION...NO MAJOR ISSUES EXPECTED TONIGHT. EXPECT THICK CIRRUS
TO CONTINUE TO STREAM IN BUT LOW CLOUDS MAY ALSO DEVELOP AS LL
WINDS PICK UP BUT THERE SHOULD BE NO VSBY RESTRICTIONS THANKS TO
THE INCREASING WIND FIELD. AS FOR RAIN WE EXPECT THINGS TO MOSTLY
HOLD OFF BUT LIGHT SHRA MAY START TO RETURN TOMORROW AND MORE SO
TOMORROW EVENING. /CAB/
&&
MARINE...WINDS WILL START TO INCREASE THIS EVENING AS THE PRESSURE
GRADIENT TIGHTENS ACROSS THE REGION. THE COMBINATION OF STRONG HIGH
PRESSURE PUSHING TOWARDS THE ATLANTIC AND CYCLOGENESIS OCCURRING IN
THE SRN PLAINS - OK/TX PANHANDLES WILL CREATE MODERATE TO STRONG
SERLY FLOW. WINDS WILL APPROACH SCS CRITERIA THIS EVENING ACROSS THE
COASTAL WATERS AND SHOULD ENCOMPASS ALL OF THE COASTAL WATERS AND
TIDAL LAKE TOMORROW. BY TOMORROW NIGHT WINDS WILL INCREASE TO NEAR
SCY CONDITIONS AS THE SFC LOW CONTINUES TO DEEPEN AND APPROACH THE
RED RIVER VALLEY. A SCY HAS ALREADY BEEN ISSUED FOR ALL OF THE
COASTAL WATERS BEGINNING LATE TOMORROW EVENING AND THEN THE TIDAL
LAKES AFTER 12Z THU. A COLD FRONT WILL PUSH THROUGH THE ALL OF THE
MARINE ZONES BY LATE TOMORROW AFTN/EVN. WINDS WILL QUICKLY VEER
AROUND TO THE NORTH BUT SHOULD REMAIN QUITE STRONG. A SCY WILL
LIKELY NEED TO BE EXTENDED INTO THE OVERNIGHT HOURS THU. THE OTHER
ISSUE WITH THE FRONT WILL BE STRONG TO SVR STORMS AS A SQUALLINE
WILL DEVELOP ALONG IT. THESE STORMS WILL EASILY BE CAPABLE OF
PRODUCING WINDS OF 40-50KTS AND IF ANY STORMS CAN DEVELOP AHEAD OF
THE SQUALLINE THEN WATERSPOUTS WILL BE A PROBLEM AS WELL. ALL STORMS
WILL COME TO AN END AFTER THE COLD FRONT MOVES THROUGH. /CAB/
&&
.PRELIMINARY POINT TEMPS/POPS...
MCB 53 66 58 67 / 30 30 90 100
BTR 56 72 59 66 / 30 30 90 100
MSY 56 73 61 72 / 10 20 80 100
GPT 53 68 59 67 / 10 30 70 100
&&
.LIX WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
MS...NONE.
GM...SMALL CRAFT ADVISORY FROM 6 AM THURSDAY TO 6 AM
FRIDAY FOR THE FOLLOWING ZONES: AND LAKE PONTCHARTRAIN AND LAKE
MAUREPAS.
SMALL CRAFT ADVISORY FROM MIDNIGHT THURSDAY TO 6 AM FRIDAY FOR
THE FOLLOWING ZONES: COASTAL WATERS FROM PASCAGOULA MS TO
THE SOUTHWEST PASS OF THE MISSISSIPPI RIVER FROM 20 TO 60
NM...COASTAL WATERS FROM PASCAGOULA MS TO THE SOUTHWEST
PASS OF THE MISSISSIPPI RIVER OUT 20 NM...COASTAL WATERS
FROM THE SOUTHWEST PASS OF THE MISSISSIPPI RIVER TO LOWER
ATCHAFALAYA RIVER LA FROM 20 TO 60 NM...AND COASTAL WATERS
FROM THE SOUTHWEST PASS OF THE MISSISSIPPI RIVER TO LOWER
ATCHAFALAYA RIVER LA OUT 20 NM.
&&
$$
