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

Home | Current Version | Previous Version | Text Only | 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
867
FXUS64 KLIX 121329
AFDLIX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEW ORLEANS LA
829 AM CDT SUN APR 12 2015

...SOUNDING DISCUSSION...
THE SOUNDING THIS MORNING REPRESENTS A TROPICAL TYPE AIRMASS. THE
PROFILE IS NEARLY SATURATED THROUGHOUT WITH PW 1.78 INCHES...
WHICH IS CLOSE TO THE DAILY MAX IN THE CLIMATOLOGY. WINDS ARE
SOUTHERLY FROM THE SFC TO 770 MB AND UNLIKE YESTERDAY THERE IS NO
LONGER AN ELEVATED INVERSION. THE SFC FRONT IS DIFFUSE AND LIKELY
BEGINNING TO ADVANCE TO THE NORTH AS A WARM FRONT. THERE IS
INSTABILITY PRESENT WITH 500 J/KG MU CAPE IN THE PROFILE AND 1300
J/KG FORECAST CAPE. PEAK WIND 100 KTS FROM THE WEST AT 175 MB.
KRAUTMANN

&&

.PREV DISCUSSION... /ISSUED 338 AM CDT SUN APR 12 2015/

TODAY...SWATH OF -RA WITH A FEW AREAS OF RA AND SHRA CONTINUED
TO MOVE NORTH INTO THE FORECAST AREA OVERNIGHT FROM THE SOUTH.
HRRR SHOWS CONTINUED -RA WITH SOME EMBEDDED HEAVIER SHOWERS
THROUGH THE DAY.

OVERALL WET PATTERN AS THE SOUTHERN STREAM REMAINS ACTIVE WITH
IMPULSES ENHANCING RAIN CHANCES THROUGH THE ENTIRE FORECAST
PACKAGE. A STALLED FRONT OVER THE COASTAL WATERS WILL RETURN
NORTH IN RESPONSE TO A DEVELOPING TROUGH IN THE WEST CONUS. AT
THE BASE OF THE TROUGH A LOW PRESSURE CENTER BEGINS TO CLOSE OFF
THIS MORNING OVER PUERTO PENASCO, MEX. DEEP GULF MOISTURE REMAINS
WITH PW VALUES AT OR ABOVE 1.70 INCHES.

FLASH FLOOD GUIDANCE AVERAGES AROUND 3 INCHES...UP TO 4 IN SOME
MS COUNTIES. AS THE WEST PATTERN CONTINUES...THESE VALUES WILL
LOWER SOME. SOME RAIN WILL BE HEAVY AT TIMES AND GET CLOSE TO
THESE FFG VALUES IN SOME AREAS. CONFIDENT IN RAINY PATTERN...NOT
AS CONFIDENT AS TO HOW MUCH AND HOW QUICKLY RAIN WILL FALL. WILL
HOLD OFF ON FLASH FLOOD WATCH... HOWEVER THAT WILL HAVE TO BE
CONSIDERED DEPENDING ON TODAYS RAIN. MARGINAL INSTABILITY AND I
HAVE NOT NOTICED LIGHTNING OVERNIGHT. ONCE THE WARM FRONT IS ON
THE MOVE AND YET ANOTHER UPPER IMPULSE MOVES IN FROM THE WEST...
THERE IS A GREATER POSSIBILITY OF TSRA THIS AFTERNOON. /KEG/

LONG TERM...ACTIVE PATTERN CONTINUES MONDAY ALL THE WAY INTO NEXT
WEEKEND. THERE WILL BE A FEW BREAKS BETWEEN IMPULSES... HOWEVER
RAIN CHANCES...MAINLY RA WITH EMBEDDED TSTMS WILL REMAIN IN THE
FORECAST ALL WEEK. ONE SUCH IMPULSE MOVES THROUGH MONDAY AHEAD OF
THE LOW CLOSED OFF PER THE GFS AROUND HOBBS NM AT 18Z MONDAY. WV
IMAGERY WILL BE A GOOD TOOL THIS WEEK TO PICK OUT AND TIME THOSE
IMPULSES MOVING THROUGH THE SOUTHERN STREAM AHEAD OF THE LOW
PRESSURE SYSTEMS MOVING FROM WEST TO EAST. ANOTHER TROUGH DIVES
DOWN THROUGH THE ROCKIES MID WEEK CLOSING OFF A LOW AROUND CHINLE
AZ AROUND 12Z THU. SIMILAR TO THIS ROUND... SEVERAL IMPULSES MOVE
OUT AHEAD OF THE LOW AND KEEP OUR RAIN CHANCES HIGH THROUGH
SATURDAY NIGHT. THIS LOW LOOKS TO BE A TAD STRONGER AS DO THE
RESPECTIVE IMPULES THUS SOME AREAS OF HEAVY RAIN LOOKS POSSIBLE.
SOME UPPER SUPPORT FOR SOME ENHANCED RAIN AREAS AS SOME UPPER
LEVEL DIVERGENCE IS EVIDENT THU. AGAIN...WE WILL HAVE TO WATCH
EACH CONSECUTIVE ROUND OF RAIN TO GAUGE THE ISSUANCE OF A FLASH
FLOOD WATCH. REGARDLESS... SOME AREAS COULD SEE HEAVY RAIN
THROUGHOUT THE FORECAST PERIOD. /KEG/

AVIATION...MVFR TO OCCASIONAL IFR CEILINGS WILL IMPACT MOST IF NOT
ALL TERMINALS DURING THE EARLY MORNING HOURS AND THROUGH THE
REMAINDER OF THE TAF FORECAST PERIOD AS SHRA AND TSRA INCREASE IN
COVERAGE. LIGHT TO MODERATE RAIN IS ALREADY IMPACTING A GOOD PORTION
OF SELA AND INTO SWRN MS AND WILL GRADUALLY EXPAND OVER THE REST OF
THE CWA THROUGH THE MORNING. THE RAIN WILL MAINLY BE LIGHT...BUT
COULD BE MODERATE AT TIMES WHERE EMBEDDED THUNDERSTORMS OCCUR.
COVERAGE AND INTENSITY IS EXPECTED TO INCREASE DURING THE AFTERNOON
HOURS. /CAB/


MARINE...STALLED FRONT NEAR THE COAST WILL RETREAT BACK TO THE
NORTH CAUSING WINDS TO RETURN BACK TO AN ONSHORE DIRECTION TODAY. AT
THE SAME TIME A LARGE AREA OF HIGH PRESSURE WILL BECOME CENTERED
OVER THE MID ATLANTIC COAST TONIGHT. THIS WILL TIGHTEN THE PRESSURE
GRADIENT OVER THE GULF AND LEAD TO MODERATE TO EVEN TEMPORARY STRONG
ONSHORE FLOW AT TIMES THE NEXT FEW DAYS. ONSHORE FLOW WILL CONTINUE
THROUGH THE WORK WEEK AND COULD RESULT IN ABOVE NORMAL TIDES
DEPENDING ON THE STRENGTH OF THE WINDS. /CAB/

DECISION SUPPORT...
DSS CODE...BLUE.
DEPLOYED...METS TO AVONDALE AND NEW ORLEANS COMMAND CENTER
ACTIVATION...YES.
ACTIVITIES...FRENCH QUARTER FEST PUBLIC SAFETY SUPPORT
             GRAND PRIX OF LOUISIANA PUBLIC SAFETY 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 TONIGHT RISK SVR
         AND/OR DIRECT TROPICAL THREATS; EVENTS OF NATIONAL
         SIGNIFICANCE

&&

.PRELIMINARY POINT TEMPS/POPS...
MCB  76  66  78  65 /  70  70  80  50
BTR  77  67  79  67 /  80  60  70  40
ASD  78  68  80  67 /  70  60  70  40
MSY  76  70  80  69 /  70  60  70  40
GPT  74  70  78  70 /  70  60  70  50
PQL  77  70  80  70 /  70  60  70  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.