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

Home | Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36
030
FXUS64 KLIX 010142
AFDLIX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEW ORLEANS LA
842 PM CDT THU JUL 31 2014

.SOUNDING DISCUSSION...

ROUTINE EVENING SOUNDING TERMINATED NEAR THE LAKE PONTCHARTRAIN
SHORELINE JUST SOUTHWEST OF LACOMBE AT ABOUT 110K FEET.

VERY LITTLE CHANGE IN MOISTURE FROM THE MORNING SOUNDING WITH A
PRECIPITABLE WATER VALUE OF 1.62 INCHES. NOT SEEING THE WARM NOSE
THAT WAS BETWEEN 800 AND 850 MB THIS MORNING...WHICH WILL MAKE THE
AIRMASS A LITTLE MORE CONDUCIVE TO CONVECTIVE DEVELOPMENT. CELL
MOVEMENT STILL LOOKS TO BE RATHER SLOW...325/6 KNOTS. FREEZING
LEVEL IS AT 15.9K FEET...AND -20C IS AT 26.5K FEET. CAPE IS AROUND
1000 J/KG AND LIFTED AROUND -2. WIND REGIME WAS RATHER LIGHT IN
THE LOWEST 2 KM...THEN WEST TO NORTHWEST THROUGH 150 MB. STRONGEST
WINDS WERE ACTUALLY ABOVE THE TROPOPAUSE ON THIS FLIGHT...WITH MAX
WIND BELOW 200 MB ONLY 26 KNOTS.

&&

.PREV DISCUSSION... /ISSUED 402 PM CDT THU JUL 31 2014/

DISCUSSION...
A WETTER THAN RECENT PATTERN STILL LOOKS TO BE IN STORE FOR THE
WEEKEND AND EARLY NEXT WEEK. CURRENT UPPER LEVEL PATTERN SHOWS A
LONG WAVE TROUGH SITUATED OVER THE EASTERN HALF OF THE UNITED
STATES...EXTENDING ALL THE WAY SOUTH TO THE GULF COAST. A RIDGE IS
CENTERED ACROSS THE US/MEXICAN BORDER AND PROTRUDES NORTH ACROSS THE
ROCKIE MOUNTAINS. A WEAK SURFACE LOW AND ASSOCIATED FRONTAL BOUNDARY
THAT IS SLOWLY MOVING ACROSS EASTERN TEXAS WILL FINALLY MAKE ITS WAY
TO LOUISIANA LATER TONIGHT INTO FRIDAY.

CURRENT RADAR SHOWS QUITE A BIT OF ACTIVITY MOVING SOUTHEAST ACROSS
NORTHERN PORTIONS OF LOUISIANA. HOWEVER...DRIER AIR IN PLACE HAS
BEEN EVAPORATING MUCH OF THE RAIN AS IT MOVES IN. LOCAL SOUNDING
CONFIRMS THIS SHOULD BE THE CASE WITH THERE STILL BEING A DRY LAYER
LEFT IN THE MID LEVELS. THIS TOP DOWN PROCESS IS TYPICALLY W/IN A
MORE STABLE ATMOSPHERE AND THUS LESS LIGHTNING ASSOCIATED WITH
STORMS. SO HAVE LOWER THUNDER PROB TO ISOLATED VS MATCHING POPS
THROUGH TOMORROW. AFOREMENTIONED FRONTAL BOUNDARY WILL SAG SOUTH
TOWARDS THE CWA AND STALL OVER THE WEEKEND. THIS WILL BE THE MAIN
FOCUS FOR INCREASE RAIN CHANCES AND HAVE NOT MADE MANY CHANGES IN
THE PREVIOUS FORECAST POPS. PRECIP WATER VALUES STILL LOOK LIKE THEY
WILL BE NEAR 2 INCHES...SO LOCALIZED FLASH FLOODING COULD BE AN
ISSUE AT TIMES AS RAINFALL RATES WILL BE QUITE HIGH.

BERMUDA RIDGE WILL BUILD WESTWARD ACROSS THE GULF OF MEXICO MIDDLE
OF THE WEEK AND ONWARD. THIS MAY BE ENOUGH TO CUTOFF MOISTURE FLOW
FROM THE SOUTHWEST WHICH WOULD LOWER RAIN CHANCES TO 20 PERCENT OR
LESS.

MEFFER

AVIATION...
VFR CONDITIONS ARE EXPECTED TO PREVAIL EVEN AS CLOUD LAYERS THICKEN
AT TIMES THROUGH MOST OF FRIDAY MORNING. CIGS AT OR ABOVE 090 ARE
EXPECTED...ALTHOUGH SOME LOWER CIGS AROUND 040 COULD OCCUR AROUND
KBTR BETWEEN 15-18Z FRIDAY AND SOME OTHER AIRPORTS AFTER 18Z. THERE
COULD BE SOME LIGHT RAIN AND A FEW LIGHT RAIN SHOWERS STARTING IN
NORTHWEST AREAS AND SPREADING SOUTHEAST LATER TODAY OR TONIGHT WITH
A BETTER CHANCE ON FRIDAY. AT THIS TIME...COVERAGE AND CONFIDENCE
ARE NOT HIGH ENOUGH TO INCLUDE IN THE TAFS. 22/TD

MARINE...
LIGHT WINDS AND LOW SEAS ARE EXPECTED TO PREVAIL THROUGH THE NEXT 5
DAYS. THE COASTAL WATERS UNDERGO TRANSITION TO A MORE TYPICAL
LAND/SEA BREEZE REGIME IN COMING DAYS AS A WEAK PRESSURE FIELD
REMAINS IN PLACE ACROSS THE NORTH GULF. 24/RR

MEFFER

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

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  67  87  69  90 /  40  40  40  40
BTR  70  88  71  90 /  40  50  40  40
ASD  68  88  71  90 /  30  40  40  40
MSY  73  87  75  90 /  30  40  40  40
GPT  68  90  73  90 /  30  40  40  40
PQL  66  88  71  89 /  30  40  40  40

&&

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

$$







USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.