404  
FXUS64 KLZK 180537  
AFDLZK  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE LITTLE ROCK AR  
1137 PM CST SAT FEB 17 2018  
   
AVIATION
 
 
A COMPLEX AVIATION FORECAST IS UNFOLDING WITH WIDESPREAD, DENSE  
FG ALREADY OBSERVED. ADJUSTED FORECAST TO INCLUDE MORE IFR AND  
WORSE RESTRICTIONS, BEGINNING NOW AND LASTING THROUGH AT LEAST  
18/14-15Z. SOME MVFR TO VFR IS POSSIBLE INTO EARLY PM AS FG  
LIFTS, BUT SHRA RETURNS S-TO-N AFTER 18/18Z WITH CIGS LOWERING TO  
BORDERLINE IFR/MVFR. LLWS ALSO LIKELY ALL SITES AS EARLY AS LATE  
AM WITH STRENGTHENING SE SURFACE FLOW AND APPROACHING 50 KTS OF SW  
FLOW DEVELOPING ALOFT. FORECAST CONFIDENCE REMAINS VERY LOW.  
 
COOPER/57  
 

 
   
PREV DISCUSSION
 
(ISSUED 535 PM CST SAT FEB 17 2018)  
 
PREV DISCUSSION...(ISSUED 308 PM CST SAT FEB 17 2018)  
SHORT TERM...TONIGHT THROUGH MONDAY  
DATA FROM KLZK RADAR INDICATE SCATTERED LIGHT RAINFALL, MOVING  
EAST ACROSS SOUTHEAST SECTIONS OF THE FORECAST AREA. THIS ACTIVITY  
IS EXPECTED TO CLEAR THE FORECAST AREA BY 00Z. WITH A WEAK NEAR  
SURFACE FLOW, AND CLEARING CONDITIONS, EXPECT SCATTERED AREAS OF  
FOG DEVELOPMENT OVERNIGHT.  
 
SOME AMPLIFICATION OF THE OVERALL UPPER FLOW ACROSS THE U.S.  
DURING THIS PERIOD. SOUTHERLY LOW LEVEL FLOW WILL DEVELOP EARLY IN  
THIS PERIOD, AND WILL PROMOTE ISENTROPIC LIFT AND MOISTURE  
TRANSPORT TO THE REGION. OVERALL, PRECIPITATION AMOUNTS WILL BE  
LIGHT DURING THIS PERIOD, WITH MORE SUBSTANTIAL PRECIPITATION  
EXPECTED LATER IN THE WEEK.  
 
LONG TERM...TUESDAY THROUGH SATURDAY  
THE EXTENDED PERIOD AND BEYOND LOOKS VERY UNSETTLED. IT WILL  
FEATURE A BATTLE BETWEEN COLDER THAN AVERAGE CONDITIONS OVER  
NORTHERN/WESTERN SECTIONS OF THE COUNTRY COLLIDING WITH MUCH  
WARMER THAN AVERAGE AIR OVER THE SOUTHEAST. BETWEEN THE TWO AIR  
MASSES, FRONTS WILL BE THE FOCUS FOR HEAVY/EXCESSIVE RAIN, WITH  
MOISTURE PROVIDED BY A PERSISTENT SOUTH/SOUTHWEST WIND FLOW ALOFT.  
 
ONCE SUCH FRONT WILL APPROACH FROM THE NORTH AS THE PERIOD BEGINS.  
SHALLOW COLD AIR WILL BE FOUND BEHIND THE FRONT, AND THE FRONT WILL  
BE MOSTLY PARALLEL TO THE UPPER FLOW. GIVEN THIS, THE FRONT WILL BE  
IN NO RUSH TO PUSH THROUGH THE REGION.  
 
AREAS OF RAIN WILL DEVELOP, AND IT WILL BE HEAVY AT TIMES. SCATTERED  
THUNDERSTORMS WILL POP UP AS WELL. THE SWATH OF PRECIPITATION WILL  
SLOWLY WORK TO THE SOUTHEAST WITH THE FRONT THROUGH WEDNESDAY, WITH  
THE FRONT FINALLY COMING TO A HALT ALONG THE GULF COAST BY SOMETIME  
THURSDAY.  
 
THE FRONT WILL BE FOLLOWED BY A LARGE AREA OF HIGH PRESSURE. AS THE  
HIGH EXITS TO THE EAST LATE IN THE WEEK, THE FRONT WILL LIFT BACK TO  
THE NORTH, AND WILL BRING ANOTHER ROUND OF RAIN.  
 
THERE COULD BE A LITTLE WINTRY PRECIPITATION LATE WEDNESDAY  
NIGHT/EARLY THURSDAY AS TEMPERATURES BOTTOM OUT JUST BELOW  
FREEZING IN NORTHERN ARKANSAS. A PERIOD OF LIGHT FREEZING RAIN  
WILL BE POSSIBLE.  
 
AS FAR AS RAINFALL, THREE TO FIVE INCH AMOUNTS ARE IN THE FORECAST  
BY THE END OF PERIOD. THERE COULD BE LOCALLY MORE THAN HALF A FOOT.  
FLOOD/FLASH FLOOD ISSUES WILL DEPEND ON WHERE THE HEAVIEST RAIN  
FALLS. IF THE EVENT IS MAINLY OVER THE NORTH/WEST WHERE IT HAS BEEN  
DRY FOR AWHILE, ISSUES WOULD NOT BE AS SIGNIFICANT AS FARTHER  
SOUTH/EAST WHERE IT HAS BEEN VERY WET. THIS SITUATION WILL BE  
MONITORED CLOSELY.  
 
TEMPERATURES WILL WAVER THROUGH THE PERIOD. IT WILL BE A MILD START,  
WITH CLOSER TO SEASONAL READINGS AS THE FRONT SAGS THROUGH THE AREA.  
LATE IN THE WEEK, IT WILL BE MILD AGAIN AS THE FRONT LIFTS TOWARD  
THE MISSOURI BORDER.  
 

 
   
LZK WATCHES/WARNINGS/ADVISORIES
 
 
DENSE FOG ADVISORY UNTIL 9 AM CST SUNDAY FOR BRADLEY-CALHOUN-  
CLARK-CLEBURNE-CLEVELAND-CONWAY-DALLAS-FAULKNER-GARLAND-GRANT-  
HOT SPRING-INDEPENDENCE-IZARD-JACKSON-JEFFERSON-LOGAN-LONOKE-  
MONTGOMERY-OUACHITA-PERRY-PIKE-POLK-POPE-PRAIRIE-PULASKI-SALINE-  
SCOTT-SHARP-STONE-VAN BUREN-WHITE-WOODRUFF-YELL.  
 

 
 

 
 
AVIATION...57  
 
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