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

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FXUS64 KLIX 142127
AFDLIX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEW ORLEANS LA
327 PM CST SUN FEB 14 2016


.DISCUSSION...AIR MASS MODIFICATION RAPIDLY OCCURRING TODAY.
DEWPOINTS HAVE RISEN AS MUCH AS 25 DEGREES FROM THIS MORNING TO NOW
AS THE RESULT OF SOUTHEASTERLY ONSHORE FLOW BECOMING WELL
ESTABLISHED AS SURFACE RIDGE TO THE NORTH SHIFTED EAST AND STARTED
PUMPING MOISTURE BACK INTO THE AREA. TEMPERATURES HAVE BEEN MODERATING
AS WELL WITH 500MB HEIGHTS ON THE RISE. BLENDED MODELS CONTINUE TO
BE TOO COLD WITH FCST HIGHS SO ONCE AGAIN WILL KEEP MAX TEMPS AT TO
A COUPLE DEGREES ABOVE MAV GUIDANCE THROUGH MONDAY.

UPPER LEVEL TROUGH WILL BE RACING SOUTHEAST ACROSS THE CENTRAL
PLAINS MONDAY AND THEN THE GULF COAST MONDAY EVENING INTO THE
OVERNIGHT PERIOD. SFC TROUGH IN CENTRAL TEXAS WILL GET PICKED UP BY
THE UPPER LOW AND WILL TRACK ACROSS NORTHERN LA AND MS. MODELS STILL
NOT CONSISTENT ON HOW DEEP THE LOW WILL BE AND HOW FAST IT WILL BE
INTENSIFYING FROM MONDAY 18Z-00Z....WHEN IT WILL IMPACT THE LOCAL
CWA THE MOST.

MODEL SOUNDINGS HAD BEEN SHOWING A VERY DYNAMICALLY DRIVEN SYSTEM
WITH STRONG WINDS RIGHT OFF THE SFC AND 250MB WINDS AROUND 100KTS.
OVER THE LAST COUPLE DAYS FCST WIND VALUES HAVE BEEN GRADUALLY
DROPPING. NOW LATEST SHOWS 500MB WINDS OF BARELY 50 KTS AND BULK
SHEAR OF 30-40 KNOTS. BOTH VALUES MARGINAL NUMBERS FOR SEVERE. ON
THE OPPOSITE END OF THE SPECTRUM...FORECAST INSTABILITY IS HIGHER
THAN PREVIOUSLY SHOWN WITH GFS BUFR SOUNDINGS SHOWING SB AND MU CAPE
IN THE 800-1100 J/KG RANGE. OVERALL MOISTURE CONTENT DOES LOOK
MEAGER WITH PRECIP WATER NOT A WHOLE LOT HIGHER THAN AN INCH. SO
THINKING IS STILL THAT A FEW STRONG TO POSSIBLY SEVERE THUNDERSTORMS
WILL BE POSSIBLE MONDAY AFTERNOON. SPC DOES HAVE A SLIGHT RISK IN
PLACE FOR PORTIONS OF THE CWA...HOWEVER...THAT IS PROBABLY A LITTLE
TOO AGGRESSIVE WITH A MARGINAL RISK MORE APPROPRIATE BASED ON
FORECASTED SVR WX PARAMETERS. IN ADDITION...LOCATION OF ANY STRONGER
ACTIVITY IS MORE LIKELY ALONG AND NORTH OF I-12 WHERE INSTABILITY
WILL BE HIGHER. LOCATIONS CLOSER TO THE COAST WILL MORE LIKELY BE
HINDERED WITH BUOYANCY DUE TO COOLER GULF WATERS. KEPT PREVIOUS
FORECAST POPS MONDAY AFTERNOON OF UPWARDS OF 80 PERCENT.
REGARDLESS...THE SYSTEM SHOULD BE VERY PROGRESSIVE AND OUT OF THE
AREA QUICKLY. TRIMMED POPS OFF SLIGHTLY QUICKER THAN PREVIOUS
FORECAST BASED ON LATEST MEDIUM RANGE MODEL TRENDS.

POST FRONTAL HIGH PRESSURE COMING FROM THE WEST TUESDAY WILL NOT
HAVE ANY COOLER TEMPS WITH THAT AIR MASS...JUST DRY CONDITIONS. SO
WILL EXPERIENCE WARMER TEMPS TUESDAY. THE TREND WILL CONTINUE
THROUGHOUT THE WEEK AND INTO THE WEEKEND AS UPPER LEVEL RIDGE TRACKS
FROM WEST TO EAST ACROSS THE CWA. HIGHS WILL MODERATE INTO THE MID
70S FRIDAY ONWARD.

MEFFER
&&

.AVIATION... VFR CONDITIONS WILL PREVAIL AT THE TERMINALS THROUGH
THE REMAINDER OF AFTERNOON AND EVENING. CEILINGS WILL LOWER INTO THE
MVFR AND IFR CATEGORIES AFTER MIDNIGHT AND PERSIST INTO MONDAY
MORNING. LIGHT FOG WILL BE POSSIBLE AT SOME LOCATIONS LATE TONIGHT
AND THROUGH THE MID MORNING HOURS. RAIN CHANCES WILL BE ON THE
INCREASE AFTER DAYBREAK...ALTHOUGH THE BEST CHANCE FOR SHOWERS AND
THUNDERSTORMS WILL HOLD OFF UNTIL AFTER 18Z. CEILINGS WILL MAINLY BE
IN THE MVFR CATEGORY MONDAY AFTERNOON. 11

&&

.MARINE...ONSHORE FLOW WILL PREVAIL THROUGH MONDAY IN ADVANCE OF AN
AREA OF LOW PRESSURE AND ASSOCIATED COLD FRONT THAT WILL MOVE ACROSS
THE COASTAL WATERS MONDAY NIGHT. EXERCISE CAUTION HEADLINES WILL
REMAIN IN THE FORECAST FOR AREAS EAST OF THE MISSISSIPPI RIVER THIS
EVENING...AND IN THE OUTER WATERS EAST OF THE RIVER THROUGH THE
NIGHT. THESE SAME HEADLINES WILL LIKELY BE NEEDED ACROSS MOST OF THE
COASTAL WATERS MONDAY. IN THE WAKE OF THE LOW AND FRONTAL
BOUNDARY...MODERATE NORTH WINDS CAN BE EXPECTED LATE MONDAY NIGHT
AND TUESDAY MORNING. A RIDGE OF HIGH PRESSURE WILL THEN PREVAIL
ACROSS THE NORTH GULF FOR THE REMAINDER OF THE WEEK WITH LIGHT TO
OCCASIONALLY MODERATE WINDS EXPECTED ACROSS THE COASTAL WATERS. 11

&&

.DECISION SUPPORT...
DSS CODE....BLUE.
DEPLOYED...NONE.
ACTIVATION...NONE.
ACTIVITIES...RIVER FLOODING CONTINUES ON THE PEARL RIVER AND
             MISSISSIPPI RIVER AT RED RIVER LANDING.
             MARGINAL/SLIGHT RISK OF SEVERE WEATHER MONDAY.

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 RISK SVR AND/OR DIRECT
         TROPICAL THREATS; EVENTS OF NATIONAL SIGNIFICANCE

&&

.PRELIMINARY POINT TEMPS/POPS...
MCB  55  69  44  70 /  30  80  20   0
BTR  56  72  48  72 /  40  80  10   0
ASD  55  71  48  70 /  30  80  30   0
MSY  56  72  52  68 /  40  80  20   0
GPT  54  68  48  67 /  30  80  40  10
PQL  50  70  45  68 /  20  80  40  10

&&

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

$$


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