006
FXUS63 KTOP 150952
AFDTOP
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TOPEKA KS
352 AM CST SUN DEC 15 2024
KEY MESSAGES
- A DENSE FOG ADVISORY IS IN EFFECT THIS MORNING LIKELY THROUGH
9 AM CST UNLESS NEEDED LONGER.
- HIGHS IN THE 50S THROUGH TUESDAY ARE EXPECTED FOLLOWED BY COOLER
TEMPERATURES IN THE 40S FOR BALANCE OF THE WEEK.
- ONLY A COUPLE SMALL CHANCES (LESS THAN 20%) FOR SHOWERS
BRIEFLY GLANCE PORTIONS OF FAR SOUTHEASTERN AREAS OVER EAST-
CENTRAL KANSAS TONIGHT AND AGAIN TUESDAY NIGHT.
DISCUSSION
ISSUED AT 348 AM CST SUN DEC 15 2024
THE UPPER AIR PATTERN ACROSS THE CONUS EARLY THIS MORNING SHOWS THE
LOW PRESSURE SYSTEM THAT EXITED THE AREA LATE YESTERDAY NOW OVER THE
OHIO VALLEY INTO THE GREAT LAKES REGION WITH ASSOCIATED COLD FRONT
POSITIONED WELL TO THE SOUTHEAST OF THE AREA NOW STALLING AND
BECOMING FULLY DETACHED FROM THE UPPER LEVEL PATTERN. A WEAK RIDGE
IS NOW TRACKING OVER THE AREA AS ADVERTISED PREVIOUSLY. THE
MEAN WESTERLIES ARE RESIDING MAINLY OVER THE NORTHERN 1/3 OF THE
CONUS WHERE SUBSEQUENT TROUGHS ARE FORECAST TO REMAIN AS THEY
ADVANCE TO THE EAST SENDING WEAKER COLD FRONTS INTO THE AREA AT
LEAST UNTIL THE MIDDLE PART OF THE UPCOMING WEEK. NEAR THE
SURFACE RESIDUAL MOISTURE AND WEAK FLOW PATTERN HAS BECOME
ESTABLISHED. CLOUDS HAVE BEEN SLOW TO EXIT THE REGION WHICH
HELPED THE NEAR SURFACE MOISTURE NOW BECOME TRAPPED UNDER THE
NOCTURNAL INVERSION AROUND 1KFT OFF THE SURFACE.
WHILE TRUE DENSE FOG APPEARS TO BE CONFINED OVER NORTH CENTRAL INTO
CENTRAL KANSAS WHERE CLEARING TOOK PLACE EARLIER LAST EVENING, THE
REST OF THE AREA HAS BEEN STEADILY EXPERIENCING OVERALL LOWER
VISIBILITY WITH FOG AT VARYING DEPTHS ACROSS THE REGION. DO
ANTICIPATE THAT AT LEAST PATCHY DENSE FOG WILL REMAIN ACROSS MOST
AREAS THROUGH MID-MORNING AND POSSIBLY LINGER INTO MIDDAY OVER SOME
LOCATIONS BASED ON HRRR, RAP AND NAM SOLUTIONS ALL SUGGESTING THAT
THE INVERSION MAY PERSIST AND BE SLOW TO MIX OUT THIS MORNING. IF
THIS PROCESS OF WINDS INCREASING IN RESPONSE TO A LEE TROUGH
DEEPENING OFF THE ROCKIES IS SLOW TO DEVELOP ACROSS THE AREA TODAY,
THEN THE DENSE FOG ADVISORY MAY NEED TO BE EXTENDED AT LEAST IN
PARTS OF THE AREA WHICH APPEARS TO BE MAINLY NORTH-CENTRAL ZONES.
EXPECT THAT ONCE CLEARING TAKES PLACE AND WINDS INCREASE THIS
AFTERNOON AND TEMPERATURES WARM NICELY INTO THE 50S AND POSSIBLY
HIT 60 OVER SOME AREAS. THE LOW AMPLITUDE RIDGE WILL QUICKLY
PROGRESS EAST OF THE AREA AS ANOTHER TROUGH DIGS INTO THE
NORTHERN PLAINS WITH SOUTHERN FLANK OF THE TROUGH AXIS HELPING
TO PUSH A MODIFIED COLD FRONT INTO THE AREA LATER THIS EVENING.
THERE MAY BE ENOUGH MOISTURE AND CONVERGENCE ALONG THIS BOUNDARY
TO PRODUCE A FEW SHOWERS OVER FAR EAST-CENTRAL AREAS BY EARLY
MONDAY MORNING. THIS PROGRESSIVE PATTERN IS MAINTAINED GENERALLY
THROUGH MID-WEEK WITH BROAD LOW AMPLITUDE RIDGING WORKING
OVERHEAD WITH QUASI-ZONAL FLOW ACROSS THE CENTRAL ROCKIES AND
ANOTHER WEAK COLD FRONT ASSOCIATED WITH AN OPEN SHORTWAVE BEING
PUSHED INTO THE REGION TUESDAY NIGHT WHICH MAY ONCE AGAIN BRING
LESS THAN A 20% CHANCE FOR SHOWERS TO FAR EAST-CENTRAL AREAS.
FROM MID-WEEK ON A MODIFIED CANADIAN HIGH PRESSURE CELL SPILLS INTO
THE NORTH-CENTRAL CONUS BRINGING A MODIFIED CP AIRMASS TO THE REGION
UNDER NORTHWEST FLOW ALOFT WHICH HELPS KEEP OVERALL COOLER
TEMPERATURES FAVORED INTO NEXT WEEKEND. MAINLY DRY CONDITIONS APPEAR
TO BE FAVORED WITH LITTLE MOISTURE ABLE TO RETURN TO THE REGION AND
MINIMAL ASCENT IN PLACE ACROSS THE FORECAST AREA.
AVIATION /06Z TAFS THROUGH 06Z MONDAY/
ISSUED AT 1130 PM CST SAT DEC 14 2024
EXPECT IFR TO VLIFR BOTH VIS/CIG CONDITIONS THROUGH 15Z ACROSS
THE TERMINALS WITH DENSE FOG POSSIBLE. CONDITIONS EXPECTED TO
IMPROVE STEADILY THROUGH 18Z WITH MARGINAL VFR CONDITIONS TAKING
HOLD THEN CIGS SCATTER INTO THE AFTERNOON AS WINDS INCREASE
FROM THE SOUTH.
TOP WATCHES/WARNINGS/ADVISORIES
DENSE FOG ADVISORY UNTIL 9 AM CST THIS MORNING FOR KSZ008-
KSZ009-KSZ010-KSZ011-KSZ012-KSZ020-KSZ021-KSZ022-KSZ023-KSZ024-
KSZ026-KSZ034-KSZ035-KSZ036-KSZ037-KSZ038-KSZ039-KSZ040-KSZ054-
KSZ055-KSZ056-KSZ058-KSZ059.
DISCUSSION...PICHA
AVIATION...DRAKE
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