660  
FXUS64 KLZK 230840  
AFDLZK  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE LITTLE ROCK AR  
340 AM CDT SAT JUN 23 2018  
   
DISCUSSION
 
 
MAIN CONCERNS IN THIS FORECAST CYCLE ARE CHANCES OF CONVECTION  
EACH DAY, AND ANY THREAT OF STRONG TO SEVERE STORMS, AS WELL AS  
LOCALIZED FLASH FLOODING DUE TO VERY MOIST ATMOSPHERE AND THE  
POTENTIAL FOR HEAVY RAIN. TEMPERATURES WILL START AROUND NORMAL TO  
A BIT BELOW NORMAL VALUES, THEN AS RAIN CHANCES LOWER INTO NEXT  
WEEK, TEMPERATURES AGAIN WILL BE ABOVE NORMAL VALUES, AS HEAT  
INDEX VALUES INCREASE.  
 
EARLY SATURDAY MORNING, THE COLD FRONT HAD BECOME NEARLY  
STATIONARY OVER CENTRAL AR, FROM NEAR DEQ TO AROUND LIT AND TO  
THE NORTHEAST TO NEAR JBR TO MEM AREA. A DRIER AIRMASS WAS BEHIND  
THE FRONT WITH A LIGHT WEST TO NORTHWEST WIND. TEMPERATURES WERE  
IN THE UPPER 60S TO LOWER 70S, WHILE DEW POINTS IN THE LOWER 60S  
TO MID 50S. SOUTH OF THE FRONT, TEMPERATURES WERE IN THE MID AND  
UPPER 70S, AND DEW POINTS IN THE LOWER 70S AND WINDS LIGHT FROM  
THE SOUTH. AN MCS ORIGINATING IN OK WAS MOVING ESE AND HAD MOVED  
INTO FAR WESTERN AR AROUND 3 AM CDT. THE COMPLEX HAD WEAKENED  
SOME, BUT STRONG GUSTY WINDS, SOME HAIL AND HEAVY RAIN HAD BEEN  
REPORTED. THIS AREA IS EXPECTED TO CONTINUE TO MOVE ESE WHILE  
SLOWLY WEAKENING. A SEVERE THUNDERSTORM WATCH WAS IN EFFECT FOR  
THE POTENTIAL OF AN ISOLATED SEVERE STORM. ALOFT, UPPER ZONAL FLOW  
HAS ALLOWED THE UPPER SHORT WAVE SYSTEM, MCS, TO MOVE THROUGH THE  
REGION AND DEVELOP THE CONVECTION. MOSTLY MID AND HIGH CLOUDS  
WERE SEEN, WITH ONLY PATCHY LOWER STRATUS CLOUDS AND FOG IN SPOTS.  
 

 
   
SHORT TERM
 
TODAY THROUGH SUNDAY NIGHT  
 
OVERALL FORECAST MODELS ARE IN GOOD AGREEMENT WITH THE DEVELOPMENT  
OF THE CONVECTION THIS MORNING. ALTHOUGH, NAM QPF FIELDS ARE THE  
LOWEST. THE HRRR HAS THE TREND OF THE CONVECTION MOVING ESE ACROSS  
AR THIS MORNING TO EARLY AFTERNOON, WHILE SLOWLY WEAKENING IT.  
THE NEARLY STALLED FRONT IS FORECAST TO LIFT A BIT MORE NORTH AND  
BE THE FOCUS OF THE CONVECTION AS THE MCS MOVES THROUGH. AN  
ISOLATED SEVERE STORM THREAT WILL BE PRESENT AS IT MOVES THROUGH,  
BUT CURRENT TRENDS ARE WEAKENING. LATER THIS EVENING AND TONIGHT,  
MODELS INDICATE ADDITIONAL UPPER SHORT WAVE ENERGY WITHIN THE  
UPPER ZONAL FLOW WILL AGAIN MOVE ACROSS AR, WHILE MAINLY OVER THE  
NORTHERN HALF. AGAIN ISOLATED STRONG TO SEVERE STORMS ARE  
POSSIBLE, WITH WINDS AND HAIL THE MAIN THREATS. HAVE KEPT THE  
HIGHEST POPS OVER NORTHERN AR TONIGHT TO SUNDAY. ON SUNDAY, MUCH  
OF THE CONVECTION WILL STAY OVER NORTHERN AR, AS THE FRONT LIFTS  
NORTH, AND THE UPPER HIGH PRESSURE RIDGE BEGINS TO BUILD INTO THE  
REGION FROM THE WEST. OTHERWISE, TEMPERATURES WILL BE AROUND TO A  
BIT BELOW NORMAL VALUES TODAY, A BIT WARMER ON SUNDAY.  
 

 
   
LONG TERM
 
MONDAY THROUGH FRIDAY  
 
MONDAY AND TUESDAY...MODEL CONSENSUS CONTINUES TO INDICATE THAT  
THE FRONTAL BOUNDARY THAT IS BRINGING SHOWERS AND THUNDERSTORMS  
ACROSS ARKANSAS TODAY WILL MOVE NORTH INTO MISSOURI BY SUNDAY  
NIGHT. MODELS ARE ALSO CONSISTENT IN ADVERTISING A STRONG UPPER  
LEVEL TROUGH MOVING SOMEWHAT SLOWLY TO THE EAST OVER THE NORTHERN  
PLAINS FROM SUNDAY NIGHT THROUGH TUESDAY MORNING. THE LARGE SCALE  
FORCING FOR ASCENT ASSOCIATED WITH THIS UPPER TROUGH WILL REMAIN  
WELL NORTH OF ARKANSAS WHERE WEAK UPPER LEVEL RIDGING IS EXPECTED  
TO PREVAIL. HOWEVER THIS STRONG UPPER TROUGH WILL BE RESPONSIBLE  
FOR CAUSING NUMEROUS ORGANIZED AND LIKELY SEVERE THUNDERSTORMS TO  
DEVELOP ACROSS PARTS OF KANSAS AND MISSOURI. THERE IS SOME CHANCE  
THAT THESE THUNDERSTORMS COULD GENERATE A STRONG ENOUGH COLD POOL  
AND MESOSCALE CONVECTIVE VORTEX TO DRIVE SOME THUNDERSTORMS SOUTH  
INTO NORTHERN ARKANSAS DURING THIS TIME. HOWEVER WINDS ALOFT WILL  
BE ORIENTED OUT OF THE SOUTHWEST TO WEST THROUGH  
TUESDAY...LIMITING THE CHANCES FOR STORMS TO SINK SOUTH ACROSS  
ARKANSAS. WITH WEAK RIDGING IN PLACE...WE WILL START TO HEAT UP  
QUITE A BIT WITH HIGHS CLIMBING INTO THE LOWER TO MID 90S ON  
MONDAY AND INTO THE MID 90S FOR MOST LOCATIONS ON TUESDAY.  
 
WEDNESDAY...FROM TUESDAY NIGHT INTO WEDNESDAY MORNING...THE UPPER  
TROUGH MOVES EAST OVER THE UPPER MIDWEST...BRINGING WINDS ALOFT  
AROUND TO THE NORTHWEST. MODEL GUIDANCE CONSISTENTLY INITIATES  
CONVECTION ACROSS NORTHERN AND CENTRAL MISSOURI AND ALLOWS THIS  
COMPLEX TO MOVE SOUTH TOWARDS ARKANSAS. BECAUSE THE WINDS ALOFT  
WOULD GENERALLY STEER STORMS OUR WAY IN A NORTHWEST FLOW  
REGIME...WENT AHEAD AND ADDED SOME 20 TO 30 POPS TO THE FORECAST  
ALONG THE MISSOURI BORDER ACROSS NORTHERN ARKANSAS LATE TUESDAY  
NIGHT INTO WEDNESDAY MORNING TO ACCOUNT FOR A SOUTHWARD PROPAGATING  
MCS. THE STORMS MAY NOT MAKE IT OF COURSE BECAUSE OVER ARKANSAS AND  
THE SOUTHERN PLAINS...UPPER LEVEL RIDGING WILL BE GETTING STRONGER  
AND WILL SERVE TO INHIBIT STORMS ATTEMPTING TO MOVE SOUTH ACROSS THE  
STATE. THE INCREASING STRENGTH OF THE RIDGE WILL SEND TEMPERATURES  
UP INTO THE MID TO UPPER 90S FOR MOST LOCATIONS AND WILL BRING HEAT  
INDEX VALUES UP OVER 100 DEGREES ACROSS THE STATE.  
 
THURSDAY THROUGH SATURDAY...THE GFS AND ECMWF BOTH AGREE IN GENERAL  
THAT UPPER LEVEL RIDGING WILL BUILD OVER THE REGION LATE IN THE  
UPCOMING WEEK INTO THE WEEKEND. THIS WILL BRING HIGH TEMPERATURES UP  
INTO THE UPPER 90S AND MAY ALLOW A COUPLE OF LOCATIONS TO SEE THEIR  
FIRST 100 DEGREE DAY OF THE YEAR. WILL KEEP HIGHS JUST BELOW THE  
CENTURY MARK FOR NOW...BUT NOW ALL MODELS SHOW THAT THE END OF THE  
WEEK IS GOING TO BE VERY HOT ACROSS ARKANSAS. HEAT INDEX VALUES WILL  
APPROACH 105 DEGREES EACH AFTERNOON...AND A HEAT ADVISORY MAY BE  
NEEDED AS THURSDAY APPROACHES.  
 

 
   
PRELIMINARY POINT TEMPS/POPS
 
 
BATESVILLE AR 84 72 90 73 / 40 60 40 10  
CAMDEN AR 93 75 93 74 / 50 10 10 0  
HARRISON AR 83 68 88 70 / 50 70 40 10  
HOT SPRINGS AR 88 75 90 74 / 60 30 20 0  
LITTLE ROCK AR 88 75 92 75 / 50 30 20 0  
MONTICELLO AR 92 75 91 74 / 30 10 10 0  
MOUNT IDA AR 87 74 89 73 / 70 30 20 0  
MOUNTAIN HOME AR 83 70 89 71 / 50 70 40 10  
NEWPORT AR 85 72 90 74 / 50 60 40 10  
PINE BLUFF AR 90 75 92 74 / 40 20 10 0  
RUSSELLVILLE AR 87 73 91 74 / 60 50 30 10  
SEARCY AR 86 72 91 73 / 50 50 30 10  
STUTTGART AR 88 74 92 75 / 40 30 20 0  

 
   
LZK WATCHES/WARNINGS/ADVISORIES
 
NONE.  

 
 

 
 
SHORT TERM...59 / LONG TERM...CAVANAUGH  
 
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