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

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary Off
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

290
FXUS64 KLIX 190104
AFDLIX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEW ORLEANS LA
804 PM CDT FRI JUL 18 2014

.SOUNDING DISCUSSION...
TO SAY THE SOUNDING THIS EVENING IS MOISTURE RICH WOULD BE AN
UNDERSTATEMENT. PRECIP WATER VALUE IS OVER 2.25 INCHES WHICH IS IN
THE 85TH PERCENTILE FOR THIS TIME OF YEAR. THIS DEEP TROPICAL
MOISTURE HAS BEEN TRANSPORTED IN BY WEST SOUTHWEST MID LEVEL WINDS
OF JUST UNDER 50 KNOTS. ALTHOUGH MOST OF THE INSTABILITY IN THE
LOWER LEVELS DOES NOT EXIST...THERE STILL SOME ELEVATE CAPE ABOVE
750MB. SO COULD GET A FEW THUNDERSTORMS THROUGHOUT THE NIGHT.
OTHERWISE...THE POTENTIAL WILL EXIST FOR HEAVY RAIN AT LEAST FROM
A MOISTURE CONTENT SIDE.

&&

.DECISION SUPPORT...


&&

.PREV DISCUSSION... /ISSUED 328 PM CDT FRI JUL 18 2014/

SYNOPSIS...
LATEST REGIONAL RADARS SHOWED A LARGE AREA OF RAIN WITH EMBEDDED
THUNDERSTORMS EXTENDING FROM SOUTHWEST ALABAMA TO THE FORECAST
AREA TO NORTHWEST GULF. LATEST SATELLITE IMAGERY SHOWED MASS OF
CONVECTION OVER THE CENTRAL GULF WITH THE TREND OF COLDER CLOUD
TOPS MOVING EAST BUT DEVELOPING ALONG THE COAST AND OVER EXTREME
NORTHERN GULF. UPPER AIR ANALYSIS SHOWED THE SHORT WAVE FROM
SOUTHERN INDIANA TO NORTH MISSISSIPPI. PRECIPITABLE WATER VALUES
ON A PLANER VIEW AT 12Z SHOWED A MOISTURE AXIS ABV 2 INCHES FROM
CORPUS CHRISTI TO SOUTHWEST MISSISSIPPI. LATEST SURFACE MAPS
SHOWED A 1013MB LOW OVER CENTRAL LOUISIANA AND THE OLD FRONTAL
BOUNDARY NORTH OF THE FORECAST AREA. 18

DISCUSSION...
SHORT WAVE WILL CONTINUE TO LIFT NORTHEAST BUT LEAVE DEEP MOISTURE
OVER THE FORECAST AREA AND CENTRAL GULF COAST. A SLIGHT PUSH WILL
SHIFT THE FOCUS OF CONVECTION ACROSS THE MISSISSIPPI COAST AND SOUTHEAST
LOUISIANA SOUTH OF LAKE PONTCHARTRAIN TONIGHT AND SATURDAY. THE
MOISTURE AXIS WILL BE DISPLACED TO COASTAL AREAS THE THREAT OF
CONVECTION WILL REMAIN SCATTERED TO NUMEROUS IN NATURE THIS
EVENING. THEREFORE...THE FLASH FLOOD WATCH WILL BE DROPPED WITH
THIS PACKAGE. BEST HELICITIES REMAINED NORTH OF THE FORECAST AREA.
CAPE VALUES WERE AROUND 1500 TO 2000 OVER THE FORECAST AREA TO THE
COAST. STRONG STORMS DID DEVELOP BUT WIND PROFILES WERE MORE
LINEAR FARTHER SOUTH AND GUSTY STRAIGHT-LINED WINDS WERE THE
THREAT. HOWEVER...HEAVY RAINFALL DUE TO ELEVATED PW VALUES AND
SOUTHWEST FLOW THROUGHOUT THE COLUMN AHEAD OF THE MAIN SHORT WAVE
ALLOW FOR WIDESPREAD RAIN AND TRAIN A BIT. THE WAVE LIFTING
NORTHEAST...COVERAGE WILL BE SLIGHTLY LESS FOR SATURDAY AND
SUNDAY.

UPPER LEVER RIDGE WILL SLOWLY AMPLIFY OVER THE PLAINS AND ROCKIES
MONDAY THROUGH THURSDAY. THIS WILL CREATE A WEAKNESS ALONG THE EAST
SIDE OF THE RIDGE OVER THE LOWER MISSISSIPPI VALLEY. SOME
INFLUENCE OF THIS RIDGE MAY SUPPRESS STORMS MORE ACROSS THE WEST
ZONES EACH AFTERNOON TUESDAY THROUGH THURSDAY. 18

MARINE...
MODERATE WINDS EAST OF THE MISSISSIPPI RIVER WILL PROMPT A FEW EXERCISE
CAUTION HEADLINES. AS THE LOW DEEPENS OVER CENTRAL LOUISIANA AND
TRACK EAST...THE PRESSURE GRADIENT WILL TIGHTEN EAST OF THE RIVER
TONIGHT. OTHERWISE...GRADIENT WILL COLLAPSE BY SATURDAY NIGHT AND
WINDS AND WAVES WILL EASE THROUGH NEXT WEEK. 18

AVIATION...
IN GENERAL...EXPECT TO SEE MVFR CEILINGS TAKE HOLD ACROSS THE
AREA TONIGHT. CEILINGS WILL RANGE FROM 1500-2500 FEET. THERE WILL
ALSO BE SOME LINGERING LIGHT RAIN SHOWER ACTIVITY THROUGH THE
NIGHT...AND POSSIBLY SOME LIGHT PATCHY FOG FORMATION. AS A
RESULT...HAVE KEPT VISIBILITIES AT AROUND 5 MILES FOR ALL OF THE
TERMINALS TO REFLECT THIS. THE THREAT OF SIGNIFICANT CONVECTION
WITH LOWER VISIBILITIES AND CEILINGS WILL BE VERY LOW DURING
OVERNIGHT PERIODS. HOWEVER...THERE MAY BE SOME HEAVIER CONVECTION
DEVELOPING AFTER 15Z TOMORROW. THIS CONVECTION WILL TEND TO BE
FOCUSED ALONG A WEAK MESOSCALE BOUNDARY NEAR
KHUM...KMSY...KNEW...AND KGPT. 32

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  70  85  71  89 /  50  50  30  30
BTR  73  86  73  90 /  60  50  30  30
ASD  72  86  74  89 /  60  60  40  40
MSY  75  86  76  89 /  60  60  40  40
GPT  75  86  74  88 /  60  60  40  40
PQL  72  86  73  88 /  60  60  40  50

&&

.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.