298  
FXUS64 KJAN 172134  
AFDJAN  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE JACKSON MS  
434 PM CDT FRI AUG 17 2018  
   
DISCUSSION
 
 
TONIGHT AND SATURDAY:  
 
SATELLITE AND AREA RADARS SHOWING CONVECTIVE CLUSTERS OVER  
CENTRAL AND SOUTHEAST AR DEVELOPING ALONG AND JUST TO THE NORTH OF  
0-3KM THETA-E AXIS. WHILE OTHER CONVECTIVE AREAS EXIST OVER EAST  
AND SOUTHEAST MS, THE STORMS APPROACHING FROM AR WILL HAVE THE  
BEST POTENTIAL FOR SEVERE GIVEN VERTICAL TOTALS IN THE UPPER 20S  
AND 20-40 KNOTS OF DEEP LAYER SHEAR DRIVING THEM SOUTHEAST. COLD  
POOL BOUNDARY MOVING RAPIDLY SOUTH ALONG INSTABILITY GRADIENT  
LOOKS TO LINK UP WITH CLUSTER OVER SOUTHEAST AR BY LATE AFTERNOON  
WITH THE RESULTING MCS CONTINUING SOUTHEAST ALONG THE THETA-E  
GRADIENT DURING THE EARLY EVENING. THE BEST POTENTIAL FOR DAMAGING  
WIND WILL EXIST DURING THIS TIME FRAME AS THE SYSTEM MOVES INTO  
NORTHEAST LA AND WEST CENTRAL MS. CAM GUIDANCE INDICATING 30-40  
KNOTS OF MAX HOURLY GUSTS AS THIS AREA MOVES INTO THE JACKSON  
METRA AREA AROUND SUNSET, BUT THIS MAY BE UNDERDONE A BIT GIVEN  
FAVORABLE MICROBURST COMPOSITE PARAMETER.  
 
CONVECTION WILL WIND DOWN SOMEWHAT BY LATE EVENING, BUT FURTHER  
DEVELOPMENT ALONG SURFACE BAROCLINIC ZONE OVER AR SEEMS LIKELY AFTER  
MIDNIGHT WHICH WILL MOVE INTO THE AREA IN CONTINUED MID LEVEL  
NORTHWEST FLOW. MULTIPLE OUTFLOW BOUNDARIES, MID LEVEL NORTHWEST  
FLOW AND AFTERNOON HEATING WILL MAKE FOR ANOTHER CONVECTIVELY ACTIVE  
DAY SATURDAY./26/  
 
SATURDAY NIGHT THROUGH NEXT WEEK:  
 
THE ARKLAMISS WILL EXPERIENCE A FEW ACTIVE AND WET MID AUGUST  
DAYS THIS WEEKEND AND INTO EARLY NEXT WEEK BEFORE A RARE AUGUST  
COLD FRONT SWEEPS THROUGH THE REGION BY MIDWEEK NEXT WEEK.  
 
BY SATURDAY EVENING, A STALLED SURFACE FRONT THAT WILL STRETCH  
FROM NEW ENGLAND DOWN INTO THE LOWER MS RIVER VALLEY. THIS FRONT  
WILL CONTINUE TO SERVE AS A FOCUS FOR CONVECTIVE INITIATION FOR  
STORMS IN OUR REGION THROUGH SUNDAY. THE BETTER COVERAGE OF  
STORMS WILL REMAIN NORTH OF THE I-20 CORRIDOR, CLOSER TO THE  
BOUNDARY. PWATS WILL RANGE FROM 2"-2.5" THROUGH THE PERIOD  
PROVIDING THE STORMS AMPLE MOISTURE TO TAP INTO. STORMS DURING  
THIS PERIOD WILL BE EFFICIENT RAIN PRODUCERS AND SOME TRAINING OF  
STORMS IS POSSIBLE, BUT THERE WAS NOT ENOUGH CONFIDENCE IN THE  
FLASH FLOODING THREAT TO EXTEND THE LIMITED THREAT BEYOND  
SATURDAY. THERE WILL BE ENOUGH INSTABILITY AND SHEAR AROUND ON  
SUNDAY TO SUPPORT SOME SEVERE STORMS WITH THE PRIMARY THREAT  
BEING GUSTY WINDS.  
 
A DEEPER DISTURBANCE WILL BEGIN TO CROSS THE PLAINS AS WE GET INTO  
EARLY NEXT WEEK, EVENTUALLY CROSSING THE MS RIVER VALLEY AND INTO  
THE GREAT LAKES REGION. WPC HAS NOTED THAT SURFACE LOW PRESSURE  
RECORDS FOR THE UPPER OHIO VALLEY REGION IN AUGUST COULD BE IN  
JEOPARDY AS THE STRONG SURFACE LOW ASSOCIATED WITH THIS  
DISTURBANCE PUSHES EAST DRAGGING A STRONG COLD FRONT WITH IT. A  
VERY MOIST AIRMASS WILL STILL BE IN PLACE OVER THE ARKLAMISS AS  
THE FRONT APPROACHES THE REGION FROM THE WEST LATE MONDAY INTO  
TUESDAY. STORMS ALONG AND AHEAD OF THE FRONT WILL ALSO BE  
EFFICIENT RAIN PRODUCERS WITH FLASH FLOODING BECOMING A THREAT  
ONCE AGAIN. A COOLER, DRIER AIRMASS WILL BEGIN TO FILTER INTO THE  
REGION BEHIND THE FRONT, RESULTING IN A DRY END TO THE WEEK.  
 

 
   
AVIATION
 
 
18Z TAF DISCUSSION:  
AN ACTIVE CONVECTIVE PERIOD WILL BE IN STORE FOR MOST TAF SITES  
THROUGH THIS EVENING. ABUNDANT CLOUD COVER THIS AFTERNOON WILL  
LEAD TO PERIODS OF MVFR CEILINGS, ESPECIALLY WHERE STORMS OCCUR AS  
VISIBILITIES WILL BE REDUCED AND WINDS WILL BE GUSTY. THE  
CONVECTION WILL WIND DOWN SOMEWHAT BY LATE EVENING, BUT  
POSSIBILITIES WILL CONTINUE OVERNIGHT AND THROUGH THE END OF THE  
PERIOD./26/  
 

 
   
PRELIMINARY POINT TEMPS/POPS
 
 
JACKSON 73 89 73 91 / 79 59 43 63  
MERIDIAN 73 88 73 91 / 52 57 37 67  
VICKSBURG 75 93 74 92 / 76 67 50 59  
HATTIESBURG 74 91 73 91 / 25 48 20 68  
NATCHEZ 74 93 73 91 / 34 37 30 59  
GREENVILLE 74 90 72 89 / 44 59 50 60  
GREENWOOD 73 87 73 90 / 62 66 50 55  
 

 
   
JAN WATCHES/WARNINGS/ADVISORIES
 
 
MS...NONE.  
LA...NONE.  
AR...NONE.  
 

 
 

 
 
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