856  
FXUS64 KLIX 172204  
AFDLIX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE NEW ORLEANS LA  
404 PM CST THU JAN 17 2019  
   
SHORT TERM
 
 
INITIAL WEAK PACIFIC FRONTAL ZONE HAS MOVED THROUGH WITH ONLY  
MODEST LIGHT RAIN THAT ACCOMPANIED THE PASSAGE. RAPID VEERING IS  
EXPECTED TONIGHT TO ALLOW FOR STRONGER ONSHORE FLOW AND MOISTURE  
RECOVERY FOR MARINE LAYER ADVECTION. LOW CLOUD DECK LIKELY TO  
LOWER TO DENSE FOG LATER TONIGHT BUT UNCERTAIN ON WHEN THE PROCESS  
ACTUALLY ONSETS. AS A RESULT, WILL HOLD OFF ON ISSUING DENSE FOG  
ADVISORY AT THIS TIME, BUT EVENING SHIFT WILL CLOSELY MONITOR  
TRENDS AND WILL LIKELY ISSUE ONE THIS EVENING. A WARM AND HUMID  
DAY IS EXPECTED FRIDAY WITH STEADY ONSHORE FLOW AS THE PLAINS  
SYSTEM DEVELOPS AND DEEPENS.  
   
LONG TERM
 
 
STRONG COLD FRONT LOOKS TO BE ON TRACK FOR SATURDAY AFTERNOON WITH  
ARCTIC COLD AIR ADVECTION TAKING PLACE THROUGH SUNDAY. SEVERE  
WEATHER POTENTIAL SATURDAY STILL APPEARS LIMITED IN NATURE DUE TO  
SHALLOW BUT DYNAMIC INSTABILITY IN A HIGH SHEAR/LOW CAPE  
ENVIRONMENT. COLDEST MORNING STILL APPEARS TO BE MONDAY, BUT AS  
WAS ANTICIPATED AND MODEL TRENDS SUPPORT, ONLY LIGHT TO MODERATE  
FREEZE TEMPERATURES ARE NOW EXPECTED DUE TO THE SHARPNESS OF THE  
THERMAL TROUGH MOVING THROUGH. ADVECTION NEUTRALIZES BY SUNDAY  
NIGHT WITH THE EPISODIC MINIMUMS OCCURS MOSTLY ON RADIATIONAL  
COOLING AND DRAINAGE TRAJECTORIES. ARCTIC AIR FLUSHES OUT RAPIDLY  
MONDAY WITH A RELATIVELY RAPID WARMING TREND AHEAD OF CLIPPER  
SYSTEM THAT SWEEPS THROUGH THE AREA WEDNESDAY.  
 

 
   
AVIATION
 
 
A MIX OF IFR AND MVFR CONDITIONS DUE TO A PERSISTENT  
STRATUS DECK SHOULD COTNINUE AT KMCB, KHDC, AND KBTR THROUGH THE  
EVENING HOURS. TONIGHT, ADVECTION FOG WILL DEVELOP AND OVERSPREAD  
MOST OF THE REGION. EXPECT TO SEE PREVAILING LIFR CONDITIONS TO TAKE  
HOLD AT ALL OF THE TERMINALS AFTER 08Z, AND THEN PERSIST THROUGH  
MUCH OF THE MORNING HOURS TOMORROW. VISIBILITIES OF ONE MILE OR  
LESS, AND CEILINGS OF 500 FEET OR LESS CAN BE EXPECTED.  
SOME IMPROVEMENT IN CONDITIONS IS EXPECTED IN THE AFTERNOON HOURS  
TOMORROW AS THE FOG BEGINS TO LIFT. 32  
 

 
   
MARINE
 
 
LITTLE CHANGE IN THINKING FROM PREVIOUS FORECASTS.  
IMMEDIATE CONCERN IS THE RISK OF DENSE FOG DEVELOPING OVER PORTIONS  
OF THE COASTAL WATERS, ESPECIALLY IN THE SOUNDS AND TIDAL LAKES  
TONIGHT. THIS FOG SHOULD LINGER THROUGH THE MORNING HOURS TOMORROW  
BEFORE CLEARING. A COLD FRONT IS STILL PROJECTED TO MOVE THROUGH  
THE WATERS ON SATURDAY, AND A PERIOD OF SMALL CRAFT ADVISORY AND  
POSSIBLY GALE FORE WIND CONDITIONS IS EXPECTED FROM SATURDAY THROUGH  
SUNDAY EVENING IN THE WAKE OF THE FRONT. CONDITIONS SHOULD IMPROVE  
ON MONDAY AS A SURFACE HIGH MOVES THROUGH THE GULF SOUTH, BUT  
ANOTHER LOW PRESSURE SYSTEM AND COLD FRONT SHOULD PUSH WINDS AND  
SEAS BACK INTO SMALL CRAFT ADVISORY RANGE BY TUESDAY AND WEDNESDAY.  
32  
 

 
   
DECISION SUPPORT
 
 
DSS CODE: GREEN.  
DEPLOYED: NONE.  
ACTIVATION: NONE.  
ACTIVITIES: NONE.  
 
DECISION SUPPORT SERVICES (DSS) CODE LEGEND  
GREEN = NO WEATHER IMPACTS THAT REQUIRE ACTION.  
BLUE = LONG-FUSED WATCH, WARNING, OR ADVISORY IN EFFECT OR  
HIGH VISIBILITY EVENT; MARGINAL RISK SEVERE OR EXCESSIVE RAIN.  
YELLOW = HEIGHTENED IMPACTS WITH SHORT-FUSED WATCH, WARNING OR  
ADVISORY ISSUANCES; RADAR SUPPORT FOR SLIGHT RISK SEVERE OR  
EXCESSIVE RAIN.  
ORANGE = HIGH IMPACTS; ENHANCED RISK SEVERE; NEARBY TROPICAL EVENTS;  
HAZMAT OR OTHER LARGE EPISODES.  
RED = FULL ENGAGEMENT FOR MODERATE TO HIGH RISK OF SEVERE AND/OR  
EXCESSIVE RAIN; DIRECT TROPICAL THREATS; EVENTS OF NATIONAL  
SIGNIFICANCE.  
 

 
   
PRELIMINARY POINT TEMPS/POPS
 
 
MCB 52 65 59 64 / 20 0 70 90  
BTR 54 67 61 64 / 0 0 60 90  
ASD 54 65 60 66 / 10 0 30 80  
MSY 57 67 62 67 / 10 0 30 80  
GPT 55 64 58 67 / 10 0 30 70  
PQL 56 65 58 68 / 20 0 20 70  
 

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

 
 

 
 
24/RR  
32/PG  
 
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