284  
FXUS64 KLZK 300134  
AFDLZK  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE LITTLE ROCK AR  
834 PM CDT SAT APR 29 2017  
   
AVIATION
 
30/00Z TAF CYCLE  
 
CONVECTION WL CONT TO INCREASE IN AREAL COVERAGE LATER THIS  
EVENING AND DURG THE OVERNIGHT HOURS. VFR/MVFR CONDS WL PREVAIL  
OUTSIDE OF CONVECTION, WITH PERSISTENT STORMS PRODUCING IFR CONDS  
AT TIMES. ASSOCD CDFNT WL PUSH EWD ACRS AR LATER ON SUN WITH  
IMPROVING CONDS AS DRIER AIR ADVECTS INTO THE REGION. /44/  

 
   
PREV DISCUSSION
 
(ISSUED 312 PM CDT SAT APR 29 2017)  
 
SHORT TERM...TONIGHT THROUGH SUNDAY  
 
SURFACE LOW PRESSURE WAS ANCHORED OVER NORTH CENTRAL TEXAS THIS  
AFTERNOON, WITH A STATIONARY BOUNDARY STRETCHING NORTHEAST INTO  
EASTERN OKLAHOMA AND NORTHWESTERN ARKANSAS. ASCENT ACROSS THIS  
REGION HAS LED TO A DRAMATIC INCREASE IN CONVECTION THIS  
AFTERNOON, WITH NUMEROUS SHOWERS AND THUNDERSTORMS NOTED ACROSS  
WESTERN, NORTHWESTERN, AND EVEN NORTH CENTRAL ARKANSAS. OBSERVED  
RAINFALL RATES HAVE BEEN IN THE 1.50 INCH PER HOUR RANGE SO FAR IN  
THE HEAVIER BANDS, WITH HIGHFILL RECEIVING OVER 2 INCHES BETWEEN  
17Z-19Z. FLASH FLOODING HAS ALREADY BECOME A CONCERN, WITH  
SATURATED SOILS AND HEAVY RAINS LEADING TO SEVERAL WATER RESCUES  
IN THE FAYETTEVILLE AND ROGERS AREAS ALREADY TODAY.  
 
WIDESPREAD 2-4 INCH ACCUMULATIONS STILL APPEAR LIKELY ACROSS  
CENTRAL AND NORTHERN ARKANSAS THROUGH THE REMAINDER OF TODAY AND  
TONIGHT. THIS INITIAL PUSH OF CONVECTION WILL BE FOLLOWED BY A  
SECOND ROUND LATER TONIGHT AS STRONGER FORCING FOR ASCENT MOVES IN  
AHEAD OF THE UPPER LOW THAT WILL BE APPROACHING. AS SUCH, LOCALLY  
HEAVIER AMOUNTS WILL NOT BE OUT OF THE QUESTION. STORM MOTIONS,  
WHETHER THIS AFTERNOON, OR WITH THE COLD FRONT LATER TONIGHT, WILL  
BE ROUGHLY PARALLEL TO THE LINES OF CONVECTION SO TRAINING CELLS  
AND RESULTANT FLASH FLOODING WILL BE AN ISSUE. MODELS ARE STILL  
INSISTENT ON A PWAT PLUME OF ROUGHLY 2" ALONG THE COLD FRONT LATER  
TONIGHT. IN ADDITION TO NORTHERN ARKANSAS, SUSPECT THERE WILL BE  
A CONSIDERABLE FLASH FLOODING THREAT IN SOUTHERN AND SOUTHEASTERN  
ARKANSAS TONIGHT ALONG THE COLD FRONT AS IT MOVES THROUGH.  
 
THE OTHER CONCERN WILL BE SEVERE STORMS. THE SPECIAL RELEASE 18Z  
SOUNDING SHOWS AND UNCAPPED ENVIRONMENT WITH CONSIDERABLE CAPE IN  
PLACE, ON THE ORDER OF 3,700 J/KG. ANY STORMS THAT DO DEVELOP THIS  
AFTERNOON AND EVENING WILL CERTAINLY HAVE PLENTY OF INSTABILITY  
TO WORK WITH. THE LIMITING FACTOR WILL BE SHEAR AS IT PERTAINS TO  
ORGANIZED CONVECTION. THUS THROUGH THIS EVENING LARGE HAIL AND  
DAMAGING WINDS WILL BE THE PRIMARY THREAT IN ADDITION TO FLASH  
FLOODING. WHILE SHEAR ISN'T THE BEST THIS AFTERNOON, IT WILL  
IMPROVE THIS EVENING AND TONIGHT AHEAD OF THE COLD FRONT AS THE  
LOW LEVEL JET KICKS IN. MODEL SOUNDINGS SUGGEST CONVECTION FOR  
CENTRAL AND SOUTHERN ARKANSAS WILL STILL BE SURFACE-BASED, SO THE  
THREAT OF SEVERE STORMS WILL REMAIN WELL INTO THE EVENING AND  
OVERNIGHT HOURS.  
 
BY DAYBREAK SUNDAY MORNING, THE COLD FRONT WILL BE IN CENTRAL TO  
EASTERN ARKANSAS AND WORKING ITS WAY EASTWARD. SOME CONVECTION  
WILL LAG THE FRONT BUT THE RISK OF ANY STRONG TO SEVERE STORMS  
WILL BE NEARLY OVER WITH BY DAYBREAK I BELIEVE.  
 
LONG TERM...SUNDAY NIGHT THROUGH SATURDAY  
 
ON SUNDAY NIGHT, THE COLD FRONT WILL BE MOVING SOUTH AND EAST OF THE  
AREA, WITH COOLER AIR MOVING IN BEHIND IT. AS THE CLOSED UPPER LOW  
PASSES NORTH OF THE AREA, THERE WILL BE SOME WRAPAROUND CLOUD COVER  
BUT THIS SHOULD CLEAR OUT MONDAY, WITH THE BEGINNING OF THE WEEK  
BEING FAIRLY PLEASANT.  
 
SPEAKING OF THE FRONT, AS IT HITS NEARLY PARALLEL UPPER FLOW TO THE  
SOUTH OF THE STATE, IT WILL STALL OUT. AS AN UPPER TROUGH DIGS DOWN  
INTO THE ROCKIES, THE FLOW WILL AMPLIFY AGAIN, AND THIS WILL PUSH  
THE BOUNDARY BACK TO THE NORTH AS A WARM FRONT AROUND TUESDAY. THE  
FRONT LOOKS TO STALL OUT SOMEWHERE OVER ARKANSAS, WITH SEVERAL WAVES  
MOVING THROUGH AND INTERACTING WITH IT. THIS WILL MAKE SHOWERS AND  
THUNDERSTORMS A GOOD POSSIBILITY THROUGH THE END OF THE WEEK.  
 
BY LATE IN THE WEEK, SURFACE LOW PRESSURE WILL FORM ALONG THE FRONT,  
WHICH WILL GIVE IT MOMENTUM. OF COURSE, IT LOOKS LIKE THERE WILL BE  
A CUTOFF UPPER LOW DROPPING DOWN INTO THE SOUTHERN PLAINS INTO  
POSSIBLY THE ARKLATEX REGION WHICH WOULD ALSO GIVE IT A PUSH.  
 

 
   
LZK WATCHES/WARNINGS/ADVISORIES
 
 
LAKE WIND ADVISORY UNTIL 9 PM CDT SUNDAY FOR ARKANSAS-BRADLEY-  
CALHOUN-CLARK-CLEBURNE-CLEVELAND-DALLAS-DESHA-DREW-FAULKNER-  
GARLAND-GRANT-HOT SPRING-INDEPENDENCE-JACKSON-JEFFERSON-LINCOLN-  
LONOKE-MONROE-OUACHITA-PRAIRIE-PULASKI-SALINE-SHARP-WHITE-  
WOODRUFF.  
 
FLASH FLOOD WATCH THROUGH SUNDAY EVENING FOR ARKANSAS-BAXTER-  
BOONE-CLARK-CLEBURNE-CONWAY-DALLAS-FAULKNER-FULTON-GARLAND-GRANT-  
HOT SPRING-INDEPENDENCE-IZARD-JACKSON-JEFFERSON-JOHNSON-LOGAN-  
LONOKE-MARION-MONROE-MONTGOMERY-NEWTON-PERRY-PIKE-POLK-POPE-  
PRAIRIE-PULASKI-SALINE-SCOTT-SEARCY-SHARP-STONE-VAN BUREN-WHITE-  
WOODRUFF-YELL.  
 
FLASH FLOOD WATCH THROUGH SUNDAY EVENING FOR BRADLEY-CALHOUN-  
CLEVELAND-DESHA-DREW-LINCOLN-OUACHITA.  

 

 
 
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