872  
FXUS63 KTOP 200902  
AFDTOP  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE TOPEKA KS  
302 AM CST SUN JAN 20 2019  
   
SHORT TERM
 
(TODAY AND TONIGHT)  
ISSUED AT 300 AM CST SUN JAN 20 2019  
 
THE SHORT-TERM FORECAST WILL FEATURE SOME CLOUDS ROLLING BACK INTO  
THE FORECAST AREA THIS AFTERNOON AND OVERALL COLD TEMPERATURES  
TO START WITH A HINT OF A WARMING TREND INTO EARLY MONDAY.  
 
CURRENT SATELLITE AND 00Z SOUNDING DATA SHOW THAT A DEEP LONG WAVE  
TROUGH REMAIN ENTRENCHED THROUGH THE GREAT LAKES INTO PORTIONS OF  
THE SOUTHEASTERN STATES. NORTHWEST FLOW REMAINS THROUGH CENTRAL  
PLAINS WHILE A BROAD LOW AMPLITUDE LONG WAVE RIDGE IS ANCHORED OVER  
THE WESTERN HALF OF THE CONUS. AT THE SURFACE, A WEAK RIDGE REMAINS  
IN PLACE WITH WINDS CALM AND VARIABLE FOR THE MOST PART.  
 
FOR THE EARLY MORNING HOURS TODAY, CIRRUS WILL CONTINUE TO SPILL  
INTO THE REGION. THIS WILL HELP TO KEEP TEMPS FROM COOLING TOO MUCH  
MORE, BUT WITH SNOWPACK THROUGH THE EASTERN PORTIONS OF THE AREA,  
HAVE KEPT LOWS SLIGHTLY SUPPRESSED INTO THE SINGLE DIGITS. OVER  
SOUTHWESTERN PORTIONS OF THE AREA, AT LEAST LOW DOUBLE DIGITS SHOULD  
DO IT. INTO THE DAY TIME FRAME, LOW COLD AIR STRATUS WILL BUILD  
BACK INTO THE AREA AS A WEAK EMBEDDED WAVE JUST SKIRTS THE AREA.  
THIS WILL ALSO BACK WINDS SLIGHTLY AS A BACK-DOOR TROUGH IS PUSHED  
INTO THE AREA. THIS SHOULD RESULT IN A FAIRLY PRONOUNCED  
TEMPERATURE GRADIENT FROM FAR NORTHEAST AREAS TO CENTRAL KS - LOW  
20S TO MID 30S RESPECTIVELY. AS THE UPPER RIDGE TRANSLATES EAST,  
HEIGHTS SHOULD RISE SLIGHTLY. AT THE SURFACE, HIGH PRESSURE CELL  
SLIDES SOUTHEAST INTO THE WESTERN GREAT LAKES REGION WITH FLOW  
COMPONENT INTO THE FORECAST AREA VEERING TO THE SOUTHEAST. THIS  
SHOULD HELP FOSTER SLIGHT WAA INTO THE AREA. SNOWPACK IS STILL  
RESPONSIBLE FOR OVERALL SUPPRESSED LOWS OVER NORTHEASTERN AREAS, SO  
HAVE ONLY LOW TEENS WITH SLIGHTLY HIGHER LOWS SOUTHWEST TOWARD  
CENTRAL KS AROUND 20.  
   
LONG TERM
 
(MONDAY THROUGH SATURDAY)  
ISSUED AT 300 AM CST SUN JAN 20 2019  
 
MONDAY AN UPPER LEVEL RIDGE WILL BE IN PLACE ACROSS THE PLAINS AHEAD  
OF AN UPPER LEVEL TROUGH OVER THE WESTERN STATES. STRONG WARM  
ADVECTION ENSUES AS LOW PRESSURE DEEPENS IN THE LEE OF THE ROCKIES.  
THIS WILL WARM TEMPERATURES INTO THE 30S AND 40S ACROSS THE AREA  
WITH THE COOLER TEMPERATURES IN THE FAR NORTH. A LEAD SHORTWAVE  
TROUGH IS FORECAST TO EJECT OUT OF THE WESTERN CONUS UPPER TROUGH  
MONDAY NIGHT AND TUESDAY. AS IT MOVES OUT INTO THE PLAINS A  
PRONOUNCED DRY SLOT IS FORECAST TO SPREAD OVER THE CWA DRYING OUT  
THE DENDRITIC GROWTH LAYER. FORECAST SOUNDINGS SHOW SATURATION IN  
THE LOWER LAYERS SO WILL LIKELY SEE DRIZZLE MONDAY NIGHT AND FOR  
MUCH OF TUESDAY. HAVE RAISED TEMPERATURES UPWARD MONDAY NIGHT INTO  
TUESDAY MORNING AS LOWER BOUNDARY LAYER WILL REMAIN MIXED AMID  
MOISTURE AND THERMAL ADVECTION AHEAD OF THE SURFACE LOW. COLD  
ADVECTION ON THE BACKSIDE OF THE LOW WILL CHANGE ANY DRIZZLE AND  
RAIN OVER TO FREEZING DRIZZLE AND FREEZING RAIN WHICH WILL  
EVENTUALLY CHANCE OVER TO LIGHT SNOW. BETTER FORCING WILL REMAIN TO  
THE NORTH IN NEBRASKA ON TUESDAY AND HAVE HIGHEST PRECIPITATION  
CHANCES NEAR THE NEBRASKA BORDER WITHIN THE DEFORMATION AXIS IN THE  
AFTERNOON. TEMPERATURES ARE EXPECTED TO FALL THROUGH THE DAY ON  
TUESDAY SO HIGHS WILL OCCUR IN THE MORNING HOURS.  
 
THE UPPER TROUGH IS FORECAST TO MOVE EAST OF THE CWA ON WEDNESDAY.  
FOR THE END OF THE WEEK AND INTO THE NEXT WEEKEND A BROAD UPPER  
TROUGH WILL BE OVER MUCH OF THE CENTRAL AND EASTERN U.S.. EMBEDDED  
WAVES WILL MOVE THROUGH BRINGING A CHANCE OF LIGHT SNOW TO PARTS OF  
THE CWA FRIDAY NIGHT AND SATURDAY. THERE IS MUCH VARIABILITY WITH  
THIS SCENARIO WITH REGARDS TO TIMING AND STRENGTH OF THE WAVES IN THE  
NORTHWEST FLOW. TEMPERATURES ARE FORECAST TO BE COOLER THAN NORMAL  
FOR HIGHS AND NEAR NORMAL FOR LOWS FROM WEDNESDAY THROUGH  
SATURDAY.  
 

 
   
AVIATION
 
(FOR THE 06Z TAFS THROUGH 06Z MONDAY)  
ISSUED AT 1053 PM CST SAT JAN 19 2019  
 
DRY AIR WITH THE SURFACE RIDGE SHOULD MAINTAIN VFR CONDITIONS  
TONIGHT. THE RAP STILL SUGGESTS SOME MVFR STRATOCU DURING THE DAY  
SUNDAY. BUT THE NAM AND GFS ARE LESS AGGRESSIVE WITH THE LOW LEVEL  
SATURATION. SO WILL KEEP THE FORECAST VFR FOR NOW.  
 

 
   
TOP WATCHES/WARNINGS/ADVISORIES
 
 
NONE.  

 
 

 
 
SHORT TERM...DRAKE  
LONG TERM...53  
AVIATION...WOLTERS  
 
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