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

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805
FXUS64 KLIX 281323
AFDLIX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEW ORLEANS LA
823 AM CDT THU AUG 28 2014

.SOUNDING DISCUSSION...
CONDITIONS HAVEN/T CHANGED SIGNIFICANTLY FROM LAST EVENING/S
FLIGHT. STILL A VERY MOIST AIR MASS WITH PRECIPITABLE WATER OF
2.14 INCHES...OR ABOUT 120 PERCENT OF NORMAL FOR THIS TIME OF
YEAR. WITH THIS MUCH MOISTURE IN PLACE...ANY STORMS THAT DEVELOP
WILL BE CAPABLE OF PRODUCING VERY HIGH RAINFALL RATES. ALSO
AIDING IN RAINFALL PRODUCTION...LIGHT WINDS THROUGH MOST OF THE
COLUMN SHOULD RESULT IN A SLOW STORM MOTION. EXCEPTION WILL BE
ACROSS SOUTHWEST PORTIONS OF THE AREA WHERE THERE WILL BE MORE
INFLUENCE FROM THE UPPER LOW OVER THE NORTHWEST GULF. STORM MOTION
WILL BE CLOSER TO 15 KTS IN THIS AREA. ALSO STILL LOOKING AT AN
UNSTABLE AIR MASS WITH A LIFTED INDEX OF -4.4 AND CAPE OF AROUND
2600 J/KG. WITH DIURNAL HEATING BEING THE MAIN LIFTING MECHANISM
EXPECT MAINLY SHOWERS AND THUNDERSTORMS MAINLY IN THE AFTERNOON.

12Z BALLOON INFO: ROUTINE FLIGHT THIS MORNING WITH NO PROBLEMS.
THE BALLOON POPPED AT 7.1 MB...OR ABOUT 20.8 MILES ABOVE THE
GROUND. AT THE TIME IT POPPED...IT WAS LOCATED OVER NORTHERN LAKE
PONTCHARTRAIN.

&&

.PREV DISCUSSION... /ISSUED 346 AM CDT THU AUG 28 2014/

SHORT TERM...
NOT MUCH ON RADAR TO START OFF THE MORNING OTHER THAN A FEW SHOWERS
OFFSHORE. RAIN CHANCES WILL BE SIMILAR TO YESTERDAY FOR MOST
PORTIONS OF THE CWA EXPECT FOR LA COASTAL PARISHES WHERE POPS SHOULD
ONLY BE AROUND 30 PCT RATHER THAN 50S. THIS IS THE RESULT OF SURFACE
LOW IN THE WESTERN GULF CONTINUING TO TRACK FURTHER AWAY FROM THE
ARE. THE FCST IS IN THE MIDDLE BETWEEN THE GENERAL HRRR AND MODEST
GFS/ECMWF. EXPECTING HIGHER POPS TO BE IN THE WESTERN HALF OF THE
FORECAST AREA. MS COUNTIES MAY NOT SEE ANY CONVECTION.

LONG TERM...
AN UPPER LEVEL TROUGH MOVING EAST ACROSS THE CENTER OF THE ROCKY
MOUNTAINS THIS MORNING IS SPLITTING AN UPPER RIDGE THATS STRUGGLING
TO MAINTAIN ITSELF OVER THE SOUTHERN HALF OF THE COUNTRY AT THIS
TIME. BY DOING SO...THE GULF OF MEXICO WILL BE OPENED UP TO THE AREA
THROUGH THE WEEKEND WHICH WILL SET THE STAGE FOR EVEN HIGHER RAIN
CHANCES FRIDAY THROUGH SUNDAY. IMPULSES RIDING AROUND THE HIGH
CENTERED TO THE EAST WILL PASS OVER THE CWA THROUGH THIS PERIOD
WHICH WILL ENHANCE SHOWER AND THUNDERSTORM DEVELOPMENT. MODEL
SOUNDINGS SHOW ABUNDANT MOISTURE WILL BE IN PLACE WITH PRECIPITABLE
WATER VALUES ON THE ORDER OF 2 TO 2.25 INCHES. THUS THINKING
COVERAGE WILL BE FAIRLY WIDESPREAD AND RAINFALL RATES QUITE HEAVY.
HAVE INCREASED POPS ON SATURDAY TO 70 PERCENT AND THAT MAY NOT BE
HIGH ENOUGH. LOCALIZED FLOODING WILL LIKELY BE AN ISSUE IN SOME
AREAS. INCREASED CLOUD COVER AND WIDESPREAD CONVECTION SHOULD LIMIT
DAILY WARMING...SO HAVE KEPT HIGHS SLIGHTLY BELOW NORMAL.

RAIN CHANCES SHOULD START TO COME BACK DOWN STARTING NEXT WEEK AS
THE TROUGH TO THE NORTH FINALLY LIFTS AND UPPER RIDGE BUILDS BACK IN
ACROSS THE SOUTH. GFS AND ECMWF ARE SHOWING A TROPICAL WAVE MOVING
ACROSS THE YUCATAN PENINSULA GOING INTO THE MIDDLE OF NEXT WEEK. IT
REMAINS TO BE SEEN IF THIS SOLUTION MATERIALIZES. STILL WAY TOO FAR
OUT TO HAVE ANY CONCERN AT THIS POINT.

AVIATION...

VFR CONDITIONS WILL PREVAIL AT ALL OF THE TERMINALS THROUGH THE
FORECAST PERIOD WITH A SCATTERED TO BROKEN CU FIELD RUNNING AROUND
4-5K FEET. THERE MAY BE SOME LIGHT FOG DEVELOPMENT AROUND 10-12Z
THIS MORNING AT KASD...KHDC...AND KMCB WHICH COULD REDUCE
VISIBILITIES TO AROUND 4-5 MILES. ANY FOG SHOULD QUICKLY CLEAR AFTER
13Z...AS DAYTIME HEATING MIXES OUT THE BOUNDARY LAYER. SOME
SCATTERED CONVECTION MAY ALSO IMPACT KHUM BETWEEN 17Z AND 23Z. HAVE
INCLUDED VCTS WORDING TO REFLECT THIS RISK.

MARINE...

EAST-SOUTHEAST FLOW OF 10 TO 15 KNOTS AND SEAS OF 2 TO 4 FEET CAN BE
EXPECTED TODAY AS AN INVERTED TROUGH EXTENDING ACROSS THE WESTERN
GULF OF MEXICO SLOWLY MOVES INTO TEXAS.  THIS INITIAL TROUGH WILL
MOVE INTO TEXAS TONIGHT...BUT ANOTHER INVERTED TROUGH AXIS WILL MOVE
NORTH INTO THE COASTAL WATERS TOMORROW.  THIS TROUGH WILL KEEP
SOUTHEAST FLOW OF 10 TO 15 KNOTS IN PLACE THROUGH SATURDAY.  SEAS
WILL INCREASE INTO THE 3 TO 5 FEET RANGE IN THE OFFSHORE WATERS AS A
1 TO 2 FOOT SWELL TRAIN DEVELOPS IN THE GULF.  RIDGING WILL BUILD
WESTWARD FROM THE EASTERN GULF FOR THE LATTER HALF OF THE
WEEKEND...KEEPING SOUTHEAST FLOW OF 10 TO 15 KNOTS IN PLACE.  THESE
CONDITIONS WILL PERSIST INTO 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  91  71  92  74 /  20  10  30  30
BTR  93  74  92  76 /  30  20  40  40
ASD  92  74  91  78 /  30  20  50  40
MSY  90  78  90  78 /  30  20  50  40
GPT  91  75  90  79 /  20  10  50  40
PQL  91  73  90  78 /  20  10  40  30

&&

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

$$

SOUNDING...95/DM
AVIATION/MARINE...32
SHORT/LONG...MEFFER






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