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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