Area Forecast Discussion
Issued by NWS New Orleans/Baton Rouge, LA

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000
FXUS64 KLIX 140430
AFDLIX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEW ORLEANS LA
1130 PM CDT SUN JUL 13 2014

.AVIATION...
GENERALLY VFR CONDITIONS WILL PREVAIL AT THE TERMINALS THROUGH THE
TAF FORECAST PERIOD OUTSIDE ANY AREAS OF CONVECTION WHICH WILL BE
MOST PREVALENT DURING THE AFTERNOON HOURS. A FEW OF THE MORE FOG
PRONE TAF SITES MAY SEE A PERIOD OF MVFR VISIBILITIES DUE TO LIGHT
FOG DURING THE PRE-DAWN HOURS. 11

&&

.PREV DISCUSSION... /ISSUED 332 PM CDT SUN JUL 13 2014/

SHORT TERM...SCT SHRA AND TSRA HAVE IMPACTED ABOUT HALF OF THE
AREA. INTERESTING ISSUES HAVE DETERMINED WHAT AREAS HAVE SEEN RAIN
AND WHICH AREAS HAVENT AND MOST OF IT WAS DICTATED BY CLOUD COVER
THIS MORNING. MORNING CONVECTION OVER THE COASTAL AREAS QUICKLY LED
TO CLOUD COVER EXPANDING FURTHER WEST AND NORTH AND THIS HAS HAD TWO
ISSUES. FIRST AS CONVECTION MOVED INLAND IT DISSIPATED AS IS
EXPECTED EARLY IN THE MORNING BUT THE CLOUD COVER CONTINUED TO
EXPAND AND THE AREAS THAT WERE JUST AHEAD OF THE MORNING CONVECTION
BECAME OVERCAST AND THUS DID NOT QUITE WARM UP WHICH DID NOT ALLOW
CONVECTION TO FIRE. AND SECOND...AHEAD OF THE OVERCAST SKIES YOU SAW
TEMPS RISE AND A DIFFERENTIAL HEATING BNDRY SET UP CLOSER TWRDS THE
BTR AND MCB AREAS. IT IS THIS AREA THAT SAW CONVECTION FIRE AROUND
MIDDAY AND THROUGH MUCH OF THE AFTN SO FAR. SO WHAT YOU HAD WAS
CONVECTION SOUTH OF THE SELA COAST AND ALONG THE MS COAST AND UP
THROUGH MUCH OF THE SOUTHSHORE. THEN THERE WAS A VOID OF CONVECTION
UNTIL ABOUT A BAYOU SORRELL TO BATON ROUGE TO TYLERTOWN LINE. ALONG
AND NW OF THAT LINE ISLTD TO SCT CONVECTION HAS BEEN FIRING UP
THROUGH THE AFTN. TEMPS WERE ALSO A GOOD 3-6 DEGREES COOLER THAN
ANTICIPATED ACROSS THE SERN HALF OF THE CWA.

TONIGHT CONVECTION WILL SLOWLY DISSIPATE AND LIKE LAST NIGHT WORK
ITS WAY BACK TO THE COAST LIKELY MOVING COMPLETELY OFF LAND AND INTO
THE GULF DURING THE EARLY MORNING HRS. TOMORROW SHOULD BE MUCH LIKE
TODAY WITH A CHANCE OF SHRA AND TSRA BUT LIKE TODAY IT WILL BE
DIFFICULT TO DISCERN WHERE EXACTLY IT WILL RAIN AS CLOUD COVER COULD
BECOME A PROBLEM AGAIN. GENERAL TRENDS SUGGEST LOOK FOR CONVECTION
ALONG THE COAST EARLY AND SLOWLY SPREAD INLAND FROM SE TO NW THROUGH
THE MIDDAY AND AFTN HRS. A FEW STRONG STORMS WILL BE POSSIBLE BUT
NOT REALLY ANTICIPATING ANYTHING SEVERE. CONVECTION WILL SLOWLY
WEAKEN HEADING INTO MON NIGHT BUT MAY NEVER COMPLETELY DIE OFF AS AN
UNSEASONAL JULY COLD FRONT WORKS TWRDS THE REGION.

SPEAKING OF THAT COLD FRONT...MEDIUM RANGE MDLS ARE NOW IN VERY GOOD
AGREEMENT WITH BRINGING A JULY COLD FRONT (YES THAT IS CORRECT A
JULY COLD FRONT) INTO THE CWA TUE AND ALL THE WAY TO THE COAST TUE
NIGHT. THIS ALONG WITH SLIGHTLY INCREASING MID LVL FLOW AND ABUNDANT
MOISTURE SHOULD LEAD TO NUMEROUS SHRA AND TSRA TUE. THE INCREASE IN
FORCING BOTH IN THE LL AND MID LVLS ALONG WITH INSTABILITY COULD
LEAD TO A FEW POTENT STORMS TUE AFTN. THAT SAID...MID LVL FLOW IS
ONLY AROUND 20 KTS WHICH EVEN FOR THE SUMMER IS NOT A GREAT SO NOT
ANTICIPATING WIDESPREAD SVR WEATHER. IN ADDITION THE AREA MAY BECOME
CONTAMINATED WITH TOO MUCH CONVECTION BUT THERE WILL LIKELY BE A FEW
STRONG TO SVR STORMS.

LONG TERM...OVERALL NOT MUCH HAS CHANGED IN THE THINKING. MDLS
ACTUALLY APPEAR IN EVEN BETTER AGREEMENT WITH THE COLD FRONT AND
AGREE WITH THE FRONT SURGING BACK TO THE NORTH THU NIGHT/EARLY FRI.
L/W TROUGH SETS UP OVER THE ERN HALF OF THE CONUS BY LATE TUE AND
PUTS THE REGION UNDER WEAK NW FLOW WED WITH THE COLD FRONT STALLING
OVER OR JUST OFF THE COAST. THE AREA NEVER COMPLETELY WASHES OUT OF
MOISTURE SO DAILY RAIN CHANCES WILL CONTINUE. THE BIGGEST DIFFERENCE
WITH THE COLD FRONT WILL BE THAT IT WILL LEAD TO HIGHS ONLY IN THE
80S WED THROUGH FRI AND IN FACT HIGHS COULD ONLY BE IN THE LOWER TO
MID 80S SO THE CURRENT FCST MAY BE A TAD TOO WARM STILL. MORNING
LOWS WILL NOT SEE MUCH OF A CHANGE AS WE ARE NOT EXPECTING DRIER AIR
TO PUSH IN.

A STRONG PAC NW SYSTEM WILL DROP DOWN THE BACK SIDE OF THE L/W
TROUGH WED ACROSS THE SRN PLAINS THU. THIS WILL INDUCE WEAK
CYCLOGENESIS LATE THU AND EARLY FRI DRAWING THE STALLED FRONT BACK
TO THE NORTH. THIS S/W WILL THEN PUSH ACROSS THE LOWER MS VALLEY FRI
AND SHOULD LEAD TO NUMEROUS SHRA AND TSRA ONCE AGAIN.

THE S/W TROUGH WILL ACTUALLY REMAIN DRAPED OVER THE AREA HEADING
INTO SAT SO RAIN MAY CONTINUE OFF AND ON HEADING INTO THE WEEKEND.

AVIATION...VFR CONDITIONS SHOULD PREVAIL THROUGH THE FIRST PART OF
TONIGHT. AFTER THAT...MOIST GROUND CONDITIONS COMBINED WITH LIGHT
WINDS SHOULD ALLOW SOME PATCHY LIGHT FOG TO DEVELOP TOWARD DAYBREAK.
GENERALLY SPEAKING...FOG SHOULD ONLY REDUCE VISIBILITY TO MVFR
LEVELS AND SHOULD QUICKLY CLEAR AFTER 14Z. THERE WILL BE A CHANCE OF
SOME CONVECTION DEVELOPING AFTER 18Z.

MARINE...LIGHT SOUTHERLY WINDS OF AROUND 5 KNOTS WILL DOMINATE THE
COASTAL WATERS TONIGHT AND TOMORROW.  HOWEVER...A TIGHTENING
PRESSURE GRADIENT IN RESPONSE TO AN APPROACHING FRONT WHICH WILL
BECOME STATIONARY FRONT OVER THE DEEP SOUTH WILL SHIFT WINDS TO A
MORE WESTERN COMPONENT AND INCREASE WIND SPEEDS TO 10 TO 15 KNOTS
BEGINNING MONDAY NIGHT AND CONTINUING THROUGH THE END OF THE WEEK.
THIS INCREASE IN WINDS WILL PUSH SEAS FROM AROUND 1 FOOT TO 2 TO 3
FEET BY TUESDAY.

DECISION SUPPORT...
DSS CODE...GREEN.
DEPLOYED...NONE.
ACTIVATION...NONE.
ACTIVITIES...SLURRY SUPPORT

DECISION SUPPORT SERVICES (DSS) CODE LEGEND
GREEN  = NO WEATHER IMPACTS THAT REQUIRE ACTION
BLUE   = LONG FUSED WATCH/WARNING/ADVISORY IN EFFECT OR HIGH
         VISIBILITY EVENT
YELLOW = HEIGHTENED IMPACTS WITH SHORT FUSED
         WATCH/WARNING/ADVISORY ISSUANCES; RADAR SUPPORT
ORANGE = HIGH IMPACTS - SLIGHT TO MODERATE RISK SEVERE; NEARBY
         TROPICAL EVENTS; HAZMAT OR OTHER LARGE EPISODES
RED    = FULL ENGAGEMENT FOR MODERATE TO HIGH RISK SVR
         AND/OR DIRECT TROPICAL THREATS; EVENTS OF NATIONAL
         SIGNIFICANCE

&&

.PRELIMINARY POINT TEMPS/POPS...
MCB  72  89  73  87 /  30  40  30  60
BTR  73  91  74  89 /  30  40  30  60
ASD  73  90  74  89 /  20  40  30  60
MSY  76  89  75  89 /  20  40  30  60
GPT  77  88  78  88 /  20  40  30  60
PQL  72  87  73  87 /  20  40  30  60

&&

.LIX WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
GM...NONE.
MS...NONE.
GM...NONE.
&&

$$






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