329  
FXUS64 KJAN 262110  
AFDJAN  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE JACKSON MS  
410 PM CDT WED APR 26 2017  
   
..SEVERE STORMS EXPECTED TONIGHT
 
 
   
DISCUSSION
 
 
TONIGHT THROUGH THURSDAY:  
 
LATEST SATELLITE IMAGERY SHOWED AN UPPER TROUGH MOVING THROUGH THE  
PLAINS. THE FORCING AND INSTABILITY HAD FORCED A POSITIVE TILTED  
SQUALL LINE TO MATERIALIZED ACROSS THE ARKLATEX INTO SOUTHEAST  
MISSOURI. ON THE SURFACE A FRONT WAS OBSERVED ACROSS EAST TEXAS INTO  
WEST ARKANSAS WITH DEEPENING LOW PRESSURE ACROSS NORTHEAST TEXAS.  
THE RESULTANT PRESSURE GRADIENT HAS DEVELOPED GUSTY WINDS ACROSS  
THE REGION ESPECIALLY OVER THE DELTA AREA OF THE FORECAST AREA.  
THE ATMOSPHERE WAS RATHER CAPPED ACROSS THE REGION AT MID  
AFTERNOON WITH READINGS IN THE UPPER 70S TO THE LOWER 80S.  
 
FOR TONIGHT EXPECT A SQUALL LINE TO ENTER OUR WESTERN COUNTIES AND  
PARISHES BY 5 PM. INSTABILITY AND SHEAR WILL BE INCREASING FROM THE  
WEST FOR THE REMAINDER OF THIS AFTERNOON INTO THIS EVENING. WE WILL  
HAVE ANOMALOUS PWATS OF AROUND 1.8 INCHES FOR SOME DECENT RAINFALL  
RATES AS THE SQUALL LINES MOVES THROUGH THE REGION. WE COULD SEE  
RAINFALL RATES OF 1 TO 2 INCHES WITH THE LINE PASSAGE. IT LOOKS LIKE  
THE 0-3 KM BULK VECTORS WILL BE GENERALLY PARALLEL TO THE LINE. WITH  
THE LINEAR MODE IN PLAY SPC HAS TAKEN OUT THE MODERATE RISK FOR OUR  
FAR WESTERN AREA. IN THE WAKE OF THE SQUALL LINE GUSTY WINDS WILL  
TAPER OFF FROM THE WEST, THUS WIND ADVISORY CRITERIA SHOULD EXPIRE  
BY 9 PM. CAM GUIDANCE MODELS SHOW THAT THE LINE SHOULD SWEEP ACROSS  
THE AREA RATHER QUICKLY AND EXIT THE REGION BY AROUND 1 AM. THE  
PRIMARY RISK WILL BE DAMAGING WINDS, GOLFBALL SIZED HAIL, AND SOME  
TORNADOES. THE RAINS WILL EXIT THE REGION BY SUNRISE THURSDAY.  
ON THURSDAY HIGH PRESSURE WILL BUILD ACROSS THE ARKLAMISS FROM THE  
WEST.  
 
AS FAR AS TEMPERATURES ARE CONCERN LOWS TONIGHT WILL RANGE FROM THE  
LOWER 50S WEST TO THE LOWER 60S SOUTHEAST. HIGHS ON THURSDAY WILL  
RANGE FROM THE MIDDLE 70S NORTH TO THE LOWER 80S SOUTHEAST./17/  
 
THURSDAY NIGHT THROUGH WEDNESDAY...NO BIG CHANGES WERE MADE TO THE  
FORECAST. AFTER THE BOUNDARY PASSES TONIGHT, TEMPERATURES WILL BE  
NEAR NORMAL FOR A DAY. WARMTH WILL QUICKLY RETURN FRIDAY AND  
CONTINUE INTO THE SATURDAY. ANOTHER COLD FRONT WILL BRING STORMS  
AND COOLER AIR FOR A DAY OR TWO EARLY NEXT WEEK. OVERNIGHT LOWS  
MAY ALSO FALL INTO THE UPPER 40S SUNDAY NIGHT BEHIND THE BOUNDARY.  
RAIN CHANCES FOR THE NEXT DAY OR TWO WILL BE SMALL, WITH MAINLY  
ISOLATED SHOWER AND THUNDERSTORM ACTIVITY EXPECTED. BY SUNDAY, A  
DEEPENING LOW PRESSURE SYSTEM WILL HELP TO PUSH PLENTY OF MOISTURE  
INTO THE REGION. GOOD LAPSE RATES AND PASSING UPPER JETS WILL  
INCREASE THE POTENTIAL FOR SEVERE ON SUNDAY. MODELS SEEM A LITTLE  
SLOWER WITH THE SYSTEM, SO IT MAY BE SUNDAY MORNING AND AFTERNOON.  
WELL ABOVE NORMAL MOISTURE VALUES SHOULD PRODUCE MORE HEAVY  
RAINFALL. ESTIMATED AMOUNTS WERE AROUND 2-3 INCHES ACROSS THE  
AREA. COMBINED WITH HEAVY RAIN FROM TODAY AND STREAMS ACROSS THE  
REGION COULD SEE SOME RISES. FLASH FLOODING WILL ALSO BE A  
CONCERN. DEFINITELY A GOOD TIME TO CLEAR SOME DRAINS TO HELP MOVE  
THE RAIN ALONG. THE NEXT SYSTEM AROUND WEDNESDAY/THURSDAY HAS SOME  
DECENT LAPSE RATES, SO THERE COULD BE A SERIES OF SEVERE EVENTS  
WITH HAIL AND WINDS OVER THE NEXT WEEK.  
 
 
 

 
   
AVIATION
 
 
18Z TAF DISCUSSION:  
 
VFR CONDITIONS WERE OBSERVED AT ALL TAF SITES AT 18Z BUT  
SATELLITE IMAGERY SUGGESTS MVFR TO IFR CATEGORY CEILINGS WILL  
BE APPROACHING THE REGION IN THE FORM OF THUNDERSTORMS DURING THE  
OVERNIGHT HOURS. STRONG GUSTY SOUTH WINDS WILL DEVELOP TODAY WITH  
SUSTAINED SPEEDS AROUND 15-25KTS AND GUSTS TO AROUND 25-35KTS  
INTO THE EVENING. A SQUALL LINE IS EXPECTED TO MOVE IN VCTY OF GLH  
AROUND 23Z AND CONTINUE ACROSS THE AREA OVERNIGHT. THE LINE OF  
TSRA SHOULD SHIFT SE OF HBG BY 07Z. /17/  
 

 
   
PRELIMINARY POINT TEMPS/POPS
 
 
JACKSON 56 78 63 88 / 61 2 5 14  
MERIDIAN 59 80 62 87 / 63 11 8 14  
VICKSBURG 54 75 61 87 / 71 2 5 14  
HATTIESBURG 62 82 64 86 / 63 10 9 14  
NATCHEZ 54 77 62 87 / 71 2 5 14  
GREENVILLE 53 74 60 86 / 77 2 5 14  
GREENWOOD 54 74 60 86 / 61 3 4 14  
 

 
   
JAN WATCHES/WARNINGS/ADVISORIES
 
 
MS...WIND ADVISORY UNTIL 9 PM CDT THIS EVENING FOR MSZ018-019-025-034-  
035-040-041.  
 
LA...WIND ADVISORY UNTIL 9 PM CDT THIS EVENING FOR LAZ007>009-015-016-  
023>026.  
 
AR...WIND ADVISORY UNTIL 9 PM CDT THIS EVENING FOR ARZ074-075.  
 

 
 

 
 
07/17  
 
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