Scientific Forecaster Discussion

Return to Local Conditions & Forecast

Without Abbreviations
With Abbreviations

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEW ORLEANS LA
1155 PM CDT SAT JUL 4 2015

.AVIATION...
UNSETTLED AIRMASS IN THE BASE OF UPPER TROUGH PASSING THROUGH
MID-MISSISSIPPI VALLEY MAY HAVE SOME NOCTURNAL DEVELOPMENT OF
SHOWERS AND THUNDERSTORMS...AS INDICATED BY CONVECTIVE ALLOWING
SHORT-TERM MODELS. IT WILL BE DIFFICULT TO INDICATE AT ANY
PARTICULAR TERMINAL FOR INCLUSION THOUGH MODELS WOULD FAVOR
KMCB...KASD...KGPT GENERALLY IN THE 08Z-12Z TIME FRAME. RESIDUAL
MOISUTRE OVER THE REGION MAY ALSO IMPART MVFR VSBY THAT MAY BE
MIXED WITH SMOKE FROM FIREWORK DISPLAYS TONIGHT. VFR CONDITIONS
EXPECTED GENERALLY AFER 15Z OUTSIDE PERIODS OF SCATTERED
CONVECTION ON LAKE AND GULF BREEZES.

&&

.PREV DISCUSSION... /ISSUED 822 PM CDT SAT JUL 4 2015/ 

SOUNDING DISCUSSION...
WE HAVE QUITE A MOIST ATMOSPHERE IN PLACE OVER THE LOCAL AREA.
THATS EASY TO SEE JUST BY LOOKING AT THE SOUNDING WHICH SHOWS VERY
LOW DEWPOINT DEPRESSIONS THROUGHOUT THE COLUMN WITH A MAX OF ONLY
ABOUT 20 DEGREES F IN THE MID LEVELS. THIS ALL EQUATES TO NEARLY 2
INCHES FOR PRECIP WATER. IN TERMS OF WHERE THIS STANDS COMPARED TO
NORMAL PER SPC'S SOUNDING CLIMO PAGE...THIS TIME OF YEAR SHOULD
BE ABOUT 1.75" AND THE 75TH PERCENTILE IS 1.93". THE RESULT OF
THESE CONDITIONS WILL BE VERY EFFICIENT RAIN PRODUCING CELLS
THROUGHOUT THE NIGHT. MAX LOW/MID LEVEL JET IS ABOUT 35 KNOTS. SO
COULD SEE GUSTS TO 40 MPH OR SLIGHTLY HIGHER WITH PRECIP LOADING.

MEFFER

PREV DISCUSSION... /ISSUED 337 PM CDT SAT JUL 4 2015/ 

SHORT TERM...
WEAK SHORT WAVE MOVING THROUGH THE BASE OF THE BROAD MID LEVEL
TROUGH OVER THE MID SOUTH REGION HAS ENHANCED CONVECTION ACROSS
SOUTH LOUISIANA AND SOUTH MISSISSIPPI TODAY. SYNOPTIC SCALE FRONT
REMAINS NORTH OF THE FORECAST AREA...ORGANIZED SCATTERED TO
NUMEROUS CONVECTION LIKELY TO LINGER TO WELL INTO THE EVENING AND
SAG SLOWLY SLOWLY SOUTH BEFORE DIMINISHING SOME AFTER MIDNIGHT.
STRONG TO LOCALLY SEVERE THUNDERSTORM THREAT SHOULD CONTINUE
THROUGH THE EVENING HOURS AS ARMS REMAINS UNSTABLE UNTIL SUNSET.
WITH MID LEVEL TROUGH STILL LINGERING OVER THE AREA SUNDAY...KEPT
SHOWERS AND THUNDERSTORM CHANCES IN THE 50 TO 60 PERCENT RANGE ON
SUNDAY...WITH ANOTHER EARLY START TO CONVECTION LIKELY.

LONG TERM...
MID LEVEL TROUGH SHOULD START LIFTING OUT SUNDAY NIGHT AND
MONDAY...WITH MID LEVEL RIDGING BUILDING OVER THE AREA THROUGH MID
WEEK. BROAD MID LEVEL RIDGE FROM THE SW NORTH ATLANTIC INTO THE
NORTHERN GULF COAST DOMINATES THE WEATHER REGIME FROM MID WEEK TO
THE WEEKEND. THIS SHOULD EFFECTIVELY KEEP TEMPERATURES SLIGHTLY
ABOVE NORMAL...90 TO 95 RANGE...AND ONLY ISOLATED AFTERNOON
THUNDERSTORMS.

AVIATION...
GENERALLY VFR CONDITIONS OUTSIDE OF CONVECTION. SCATTERED TO
NUMEROUS SHOWERS AND THUNDERSTORMS THROUGH 04Z LOWERING CIG AND
VIS TO IFR CONDITIONS AND GUSTY WINDS TO 35 KNOTS IN THE STRONGER
THUNDERSTORMS. EXPECT CONVECTION TO BECOME MORE SCATTERED IN
COVERAGE AFTER 04Z BUT CONTINUE THROUGH OVERNIGHT HOURS.

MARINE... 
BERMUDA RIDGE EXTENDING INTO THE NORTHERN GULF COAST WILL MAINTAIN
A LIGHT SOUTHERLY FLOW FOR THE FORECAST PERIOD WITH WINDS
LESS THAN 15 KNOTS THROUGH THE PERIOD. SCATTERED TO LOCALLY
NUMEROUS THUNDERSTORMS TONIGHT AND SUNDAY WILL BECOME ISOLATED IN
COVERAGE BY MID WEEK. 

DECISION SUPPORT...
DSS CODE....BLUE. 
DEPLOYED...NONE. 
ACTIVATION...NONE. 
ACTIVITIES...RIVER FLOOD WARNINGS ON MISSISSIPPI RIVER FROM RED  
             RIVER LANDING TO BATON ROUGE.  

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 RISK SVR AND/OR DIRECT
         TROPICAL THREATS; EVENTS OF NATIONAL SIGNIFICANCE

&&

.PRELIMINARY POINT TEMPS/POPS...
MCB  72  88  73  91 /  50  60  20  20 
BTR  74  90  74  91 /  40  50  10  10 
ASD  74  89  74  91 /  60  60  20  20 
MSY  77  89  77  91 /  50  50  10  20 
GPT  76  87  76  87 /  60  60  30  30 
PQL  74  88  72  88 /  60  60  30  30 

&&

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

$$

24/RR

National Weather Service Glossary of Abbreviations