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

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073
FXUS64 KLIX 251005
AFDLIX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEW ORLEANS LA
405 AM CST WED FEB 25 2015

.DISCUSSION...SO FAR IT HAS BEEN A COLD AND CLOUDY NIGHT BUT LGT
SHRA AND DZ ARE SLOWLY DEVELOPING OVER THE REGION. THIS WILL QUICKLY
CHANGE AFTER SUNRISE AS A STRONG S/W MOVES CLOSER TWRDS THE REGION.
WIDESPREAD SHRA AND SN HAVE ALREADY DEVELOPED ACROSS CNTRL AND NERN
TX IN RESPONSE TO THIS S/W.

TODAY WILL BE THE ACTIVE DAY FOR THE REMAINDER OF THE WORK WEEK WITH
DRY WEATHER ANTICIPATED BY LATE TONIGHT AND THROUGH THE FIRST HALF OF
THE WEEKEND. AS FOR TODAY...THE MAIN PROTAGONIST WILL BE THE POTENT
S/W WORKING ACROSS THE TX. AS IT MOVES CLOSER TWRDS THE LOWER MS
VALLEY A SFC LOW IN THE WRN GULF WILL RESPOND...DEEPEN AND TRACK
THROUGH THE N-CNTRL GULF TODAY. THESE FEATURES WILL LEAD TO
INCREASING LIFT ALONG WITH DECENT LL CONVERGENCE DRAPED RIGHT OVER
THE REGION. SUFFICIENT MOISTURE WILL BE IN PLACE AS WELL AND THIS
SHOULD LEAD TO WIDESPREAD RAIN DURING THE DAY TODAY WITH ACTIVITY
LIKELY INCREASING QUICKLY THIS MORNING. THE QUESTIONS THAT COME UP
ARE...WILL THERE BE ANY FROZEN PRECIP IN THE NW...HOW MUCH RAIN WILL
THE AREA SEE...WILL THERE BE ANY THUNDER...AND WHEN WILL THE PRECIP
END. AS FOR FROZEN PRECIP...FZRA IS OUT OF THE QUESTION AS TEMPS
WILL BE ABV FREEZING AT THE SFC AND AS FOR SNOW OR SLEET...LOOKING
AT FCST SNDGS THE WARM LAYER APPEARS TO BE TOO THICK TO ALLOW FOR
FROZEN PRECIP TO EACH THE GROUND. IN ADDITION WITH THE COLUMN LIKELY
ALREADY PRETTY SATURATED THE IMPACTS OF EVAPORATIVE COOLING SHOULD
BE MINIMAL EVEN IF PRECIP INTENSITY IS HEAVY. AS FOR RAINFALL
AMOUNTS TODAY...NOT ANTICIPATING ANYTHING EXTRAORDINARY BUT
WIDESPREAD 1 INCH TOTALS ARE NOT OUT OF THE QUESTION WITH LOCALLY
HIGHER AMOUNTS POSSIBLE. WITH RESPECT TWRDS THUNDER...HAVE OPTED TO
KEEP THAT WORDING OUT. THERE WILL BE SOME ELEVATED INSTABILITY TO
WORK WITH BUT THAT INSTABILITY RESIDES AROUND H7 AND ABV. IN ADDITION
THE BEST DYNAMICS WILL BE NORTH OF THE REGION. ONE POSITIVE WITH
RESPECT TO THUNDER IS MID LVL WINDS WILL BE QUITE STRONG SO THAT MAY
PROVIDE JUST ENOUGH FORCING TO GET ONE OR TWO CLAPS OF THUNDER. THE
RAIN WILL COME TO AN END LATE THIS AFTN OR LIKELY MORE SO EARLY THIS
EVNG FROM W TO E. THE S/W WILL BE EAST OF THE REGION SHORTLY AFTER
0Z AND LL WINDS WILL QUICKLY COME AROUND TO THE NW SHUTTING PRECIP
DOWN FOR OUR REGION SHORTLY AFTER 00Z.

THU AND FRI WILL BE COLD. AN ARCTIC HIGH WILL BE DROPPING OUT OF
CANADA LATE TONIGHT AND SURGING DOWN THE PLAINS TOMORROW. THAT SAID
THE MID LVL PATTERN QUICKLY DE-AMPLIFIES WITH A RATHER BROAD L/W
TROUGH DRAPED ACROSS MUCH OF THE CONUS. THIS WILL LEAD TO THIS
AIRMASS SLOWING AS IT TRIES TO PUSH FURTHER SOUTH AND TWRDS THE
GULF. IN FACT THE CNTR OF THE HIGH ASSOCIATED WITH THIS AIRMASS WILL
TRACK ACROSS THE NRN PLAINS...THROUGH THE UPPER MS VALLEY AND INTO
THE OH VALLEY BY FRI EVNG. THAT SAID THIS IS A RATHER LARGE ARCTIC
AIRMASS WHICH WILL SUPPRESS THE MOISTURE INTO THE GULF AND BRING
ABOUT SOME CHILLY LL TEMPS OVER OUR AREA WITH AFTN HIGHS ABOUT 15 TO
POSSIBLY 20 DEGREES BELOW NORMAL THU AND FRI. MORNING LOWS
THU...FRI...AND SAT WILL BE ABOUT 10-15 DEGREES BELOW NORMAL WITH A
LIGHT FREEZE POSSIBLE EACH MORNING ACROSS THE NRN HALF/3RD OF THE
CWA.

OVER THE WEEKEND WE WILL SEE THINGS QUICKLY TRANSITION AS TEMPS
MODERATE QUICKLY AND MOISTURE RETURNS. THE ARCTIC AIRMASS WILL
QUICKLY SHIFT EAST WITH THE SFC HIGH CNTRD OVER THE MID ATLANTIC
STATES AND DEEP SRLY-SERLY FLOW SETTING UP ACROSS MUCH OF THE GULF.
THE MID LVLS BEGIN TO AMPLIFY IN RESPONSE TO A STRONG DISTURBANCE
DIGGING SOUTH OVER THE PAC COAST. THIS WILL PUT THE REGION UNDER SW
FLOW LATE SAT AND MORE SO SUN WHICH WILL BEGIN TO SEND THE FIRST IN
A SERIES OF IMPULSES ACROSS THE REGION AND RAIN CHANCES INCREASE SUN
DUE TO THIS.

NEXT WEEK WE WILL CONTINUE TO SEE THINGS WARM UP WITH TEMPS LIKELY
IN THE 70S IF NOT MID-UPPER 70S AGAIN ACROSS THE MAJORITY OF THE CWA.
THE STRONG IMPULSE THAT LED TO THE L/W TROUGH AXIS SETTING UP WEST
WILL DEPART THE DESERT SW LIFTING ACROSS THE CNTRL PLAINS DURING THE
FIRST HALF OF THE WEEK. THIS WILL TRY TO SEND A COLD FRONT INTO THE
LOWER MS VALLEY TUE/WED BUT LATEST INDICATIONS SUGGEST THIS FRONT
WILL NOT QUITE REACH THE AREA. HOWEVER IT WILL HELP KEEP RAIN
CHANCES OVER THE AREA THROUGH THE FIRST HALF OF THE WEEK. /CAB/

&&

.AVIATION...
EXPECT MVFR TO IFR CONDITIONS TO PREVAIL TODAY AS A LOW PRESSURE
SYSTEM WILL DEVELOP OVER THE GULF OF MEXICO. THIS WILL GIVE US A
GOOD SHOT AT RAINFALL TODAY INTO THIS AFTERNOON. HAVE CARRIED
PREVAILING RAIN AT ALL TERMINALS. RAIN HAS DEVELOPED OVER EAST TEXAS
AND SOME LIGHT SHOWERS ARE NOW FORMING OVER OUR FORECAST AREA. IT
SHOULD BE A WET DAY BUT CONDITIONS SHOULD IMPROVE LATE TONIGHT. 13/MH


MARINE...
A LOW PRESSURE AREA IS DEVELOPING OVER SOUTH TEXAS AND IS EXPECTED
TO MOVE INTO THE GULF OF MEXICO TODAY. THIS WILL ALLOW FOR
CONDITIONS TO REACH SMALL CRAFT ADVISORY CRITERIA OVER THE COASTAL
WATERS TODAY. COLDER AIR SHOULD MOVE INTO THE AREA BEHIND THIS
SYSTEM...AND A BUILDING HIGH PRESSURE THURSDAY AND FRIDAY SHOULD
ALLOW FOR NORTH WINDS TO PREVAIL.  A SMALL CRAFT ADVISORY WILL
CONTINUE TO RUN TODAY THROUGH LATE TONIGHT AS THE LOW MOVES THROUGH
THE WATERS. 13/MH

&&

DECISION SUPPORT...

DSS CODE...BLUE.
DEPLOYED...NONE.
ACTIVATION...NONE.
ACTIVITIES...SLURRY SUPPORT
             SMALL CRAFT ADVISORY

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  39  30  50  30 / 100  20  10  10
BTR  43  32  53  32 / 100  20  10  10
ASD  45  33  53  33 / 100  30  10  10
MSY  47  36  52  37 / 100  30  10  10
GPT  46  35  53  35 / 100  40  10  10
PQL  47  33  53  34 / 100  40  10  10

&&

.LIX WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
GM...SMALL CRAFT ADVISORY FROM 9 AM WEDNESDAY TO MIDNIGHT THURSDAY
     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...AND COASTAL WATERS FROM
     THE SOUTHWEST PASS OF THE MISSISSIPPI RIVER TO PORT
     FOURCHON OUT 20 NM.

MS...NONE.
GM...SMALL CRAFT ADVISORY FROM 9 AM WEDNESDAY TO MIDNIGHT THURSDAY
     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...AND COASTAL WATERS FROM
     THE SOUTHWEST PASS OF THE MISSISSIPPI RIVER TO PORT
     FOURCHON OUT 20 NM.

&&

$$

SHORT/LONG TERM: CAB
AVIATION/MARINE: 13/MH




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