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

Home | Current Version | Previous Version | Graphics & Text | 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 35

440
FXUS64 KLIX 212228
AFDLIX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEW ORLEANS LA
428 PM CST WED JAN 21 2015

.SHORT TERM...

NO SIGNIFICANT CHANGES IN THINKING CONCERNING THE DEVELOPMENT OF A
GULF LOW TONIGHT INTO TOMORROW. A POTENT UPPER LEVEL VORT WILL
CONTINUE TO KICK OUT OF THE FOUR CORNERS AND INTO TEXAS TONIGHT.
AS THIS SYSTEM APPROACHES FROM THE WEST...MID AND HIGH LEVEL
MOISTURE WILL STREAM INTO THE REGION...AND SKIES SHOULD TURN
MOSTLY CLOUDY BY DAYBREAK TOMORROW. THE OVERALL ATMOSPHERE WILL
MOISTEN FROM THE TOP DOWN...WITH A FULLY SATURATED AIRMASS
EXPECTED BY TOMORROW AFTERNOON. AT THE SAME TIME THAT UPPER LEVEL
OMEGA IS MAXIMIZED...WARM FRONTAL PROCESSES IN THE LOW LEVELS WILL
ALSO INCREASE ISENTROPIC FORCING OVER A COOLER AIRMASS IN THE LOW
LEVELS. WITH DEEP LAYER FORCING IN PLACE...EXPECT TO SEE
WIDESPREAD LIGHT TO MODERATE RAIN DEVELOP TOMORROW AFTERNOON AND
CONTINUE INTO THE OVERNIGHT HOURS TOMORROW.

COLDER AIR ADVECTING IN FROM THE NORTHEAST AND OVERCAST SKIES WILL
COMBINE FORCES TO KEEP TEMPERATURES IN THE UPPER 40S AND LOWER 50S
TOMORROW AFTERNOON. TEMPERATURES WILL BE LITTLE CHANGED WITH
READINGS IN THE LOWER TO MIDDLE 40S TOMORROW NIGHT GIVEN THE
SATURATED NATURE OF THE ATMOSPHERE. ON FRIDAY...AS THE LOW DEPARTS
TO THE EAST...THE MAIN PART OF THE UPPER LEVEL COLD POOL WILL MOVE
IN... AND TEMPERATURES WILL REMAIN IN THE 40S THROUGH THE DAY.
THIS COLDER AIRMASS IN THE LOW LEVELS...COMBINED WITH CONTINUED
SOUTHWEST FLOW ALOFT WILL KEEP ISENTROPICALLY FORCED CLOUDS AND
SHOWERS OVER THE AREA. SHOWER ACTIVITY WILL BE MOST PRONOUNCED IN
THE MORNING HOURS...WITH A REDUCTION IN COVERAGE BY AFTERNOON AS
SOME DRIER AIR WORKS INTO THE MID-LEVELS.

A MUCH DRIER AIRMASS WILL FINALLY BEGIN TO ADVECT INTO THE REGION
FRIDAY NIGHT...WITH PW VALUES DROPPING A GOOD HALF INCH THROUGH
THE NIGHT. MOSTLY CLOUDY SKIES AND A FEW SHOWERS IN THE EVENING
WILL GIVE WAY TO CLEARING SKIES AND DRY WEATHER BY DAYBREAK.
TEMPERATURES WILL ALSO BE SIGNIFICANTLY COOLER AS THE HEART OF THE
UPPER LEVEL COLD POOL SLIDES THROUGH. OVERNIGHT LOWS WILL DROP
INTO THE LOWER TO MIDDLE 30S ACROSS THE REGION.

A HIGHLY AMPLIFIED PATTERN WILL THEN DOMINATE THROUGH THE WEEKEND
ACROSS THE CONUS...WITH DEEP LAYER TROUGHING AND NORTHWEST FLOW IN
PLACE FOR BOTH SATURDAY AND SUNDAY. CLEAR SKIES...COOL
TEMPERATURES...AND DRY WEATHER WILL BE THE RULE. HIGHS WILL ONLY
WARM INTO THE MIDDLE SATURDAY AND SUNDAY AFTERNOON...AND OVERNIGHT
LOWS WILL COOL BACK INTO THE LOWER TO MIDDLE 30S FOR SATURDAY
NIGHT. ON AVERAGE READINGS WILL BE AROUND 5 DEGREES BELOW NORMAL.

.LONG TERM...

A REINFORCING CLIPPER SYSTEM WILL MOVE THROUGH THE GREAT LAKES
OVER THE WEEKEND...FORCING A COLD FRONT THROUGH THE FORECAST AREA
SUNDAY NIGHT. THIS FRONT WILL BE MOISTURE STARVED AND EXPECT
NOTHING MORE THAN A WIND SHIFT BACK TO THE NORTH AND ANOTHER SURGE
OF EVEN DRIER AIR INTO THE REGION. FORTUNATELY...THE MAIN HEART OF
THE COLD POOL TIED INTO THE THIS CLIPPER SYSTEM WILL REMAIN WELL
NORTH AND EAST OF THE REGION.

THE UPPER LEVEL TROUGH WILL BEGIN TO PULL TO THE EAST ON TUESDAY
AND WEDNESDAY...AND A STRONG MID AND UPPER LEVEL RIDGE AXIS WILL
BUILD OVER THE FORECAST AREA. STRONG SUBSIDENCE ACROSS THE REGION
WILL KEEP CLEAR SKIES AND LOW HUMIDITIES IN PLACE. THIS SINKING
AIRMASS WILL ALSO ALLOW TEMPERATURES TO FURTHER MODIFY...AND
EXPECT TO SEE READINGS NEAR MORE SEASONAL NORMS BOTH DAYS.

&&

.AVIATION...

VFR CONDITIONS WILL BE FOUND OVER THE TERMINALS THROUGH MIDDAY
TOMORROW. SOME MVFR CEILINGS AND VISIBILITIES COULD DEVELOP
CLOSER TO 00Z AS A SHIELD OF RAINFALL MOVES.

&&

.MARINE...

A GULF LOW WILL IMPACT THE COASTAL WATERS THROUGH SATURDAY. WINDS
WILL INCREASE INTO SMALL CRAFT ADVISORY RANGE OVER THE GULF
COASTAL WATERS AND SOUNDS TOMORROW AND REMAIN ELEVATED INTO
SATURDAY. THESE STRONG WINDS WILL ALSO PUSH SEAS TO 4 TO 8 FEET IN
THE GULF WATERS...WITH SOME HIGHER SEAS POSSIBLE WELL OFFSHORE.
THERE WILL BE BRIEF DECREASE IN WIND SPEEDS SATURDAY NIGHT AND
SUNDAY AS HIGH PRESSURE SETTLES OVER THE AREA. HOWEVER...A
REINFORCING COLD FRONT WILL SWEEP THROUGH SUNDAY NIGHT...PUSHING
NORTHWEST WINDS BACK INTO ADVISORY FOR LATE SUNDAY NIGHT AND
MONDAY. 32

&&

.DECISION SUPPORT...

DSS CODE...BLUE.
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  43  52  41  48 /  20 100 100  70
BTR  44  54  40  48 /  20 100 100  60
ASD  44  53  45  51 /  10 100 100  60
MSY  49  57  44  49 /  20 100 100  60
GPT  45  57  47  52 /  10 100 100  70
PQL  43  56  50  52 /  10 100 100  70

&&

.LIX WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
GM...SMALL CRAFT ADVISORY FROM 6 AM THURSDAY TO 6 PM FRIDAY FOR THE
     FOLLOWING ZONES: BRETON SOUND...CHANDELEUR SOUND...COASTAL
     WATERS FROM BOOTHVILLE LA TO THE SOUTHWEST PASS OF THE
     MISSISSIPPI RIVER OUT 20 NM...COASTAL WATERS FROM
     PASCAGOULA MS TO STAKE ISLAND LA FROM 20 TO 60 NM...COASTAL
     WATERS FROM PASCAGOULA MS TO STAKE ISLAND LA OUT 20
     NM...COASTAL WATERS FROM PORT FOURCHON TO LOWER ATCHAFALAYA
     RIVER FROM 20 TO 60 NM...COASTAL WATERS FROM PORT FOURCHON
     TO LOWER ATCHAFALAYA RIVER OUT 20 NM...COASTAL WATERS FROM
     STAKE ISLAND LA TO THE SOUTHWEST PASS OF THE MISSISSIPPI
     RIVER FROM 20 TO 60 NM...COASTAL WATERS FROM THE SOUTHWEST
     PASS OF THE MISSISSIPPI RIVER TO PORT FOURCHON FROM 20 TO
     60 NM...COASTAL WATERS FROM THE SOUTHWEST PASS OF THE
     MISSISSIPPI RIVER TO PORT FOURCHON OUT 20 NM...LAKE
     BORGNE...AND MISSISSIPPI SOUND.

MS...NONE.
GM...SMALL CRAFT ADVISORY FROM 6 AM THURSDAY TO 6 PM FRIDAY FOR THE
     FOLLOWING ZONES: BRETON SOUND...CHANDELEUR SOUND...COASTAL
     WATERS FROM BOOTHVILLE LA TO THE SOUTHWEST PASS OF THE
     MISSISSIPPI RIVER OUT 20 NM...COASTAL WATERS FROM
     PASCAGOULA MS TO STAKE ISLAND LA FROM 20 TO 60 NM...COASTAL
     WATERS FROM PASCAGOULA MS TO STAKE ISLAND LA OUT 20
     NM...COASTAL WATERS FROM PORT FOURCHON TO LOWER ATCHAFALAYA
     RIVER FROM 20 TO 60 NM...COASTAL WATERS FROM PORT FOURCHON
     TO LOWER ATCHAFALAYA RIVER OUT 20 NM...COASTAL WATERS FROM
     STAKE ISLAND LA TO THE SOUTHWEST PASS OF THE MISSISSIPPI
     RIVER FROM 20 TO 60 NM...COASTAL WATERS FROM THE SOUTHWEST
     PASS OF THE MISSISSIPPI RIVER TO PORT FOURCHON FROM 20 TO
     60 NM...COASTAL WATERS FROM THE SOUTHWEST PASS OF THE
     MISSISSIPPI RIVER TO PORT FOURCHON OUT 20 NM...LAKE
     BORGNE...AND MISSISSIPPI SOUND.

&&

$$

32





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