915
FXUS64 KMEG 210154
AFDMEG
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MEMPHIS TN
754 PM CST MON JAN 20 2025
..NEW UPDATE
UPDATE
ISSUED AT 754 PM CST MON JAN 20 2025
A BROAD, POSITIVELY-TILTED, UPPER-LEVEL TROUGH IS CURRENTLY
AFFECTING THE BULK OF THE CONUS THIS EVENING. STRONG FLOW ALOFT
FROM THE WEST-SOUTHWEST CONTINUES ACROSS THE LOWER MS VALLEY
DOWNSTREAM OF A SHORTWAVE TROUGH CURRENTLY APPROACHING THE OZARKS.
THE LOW- LEVEL WATER VAPOR CHANNEL (7.34 UM) SHOWS AN AREA OF
ASCENT OVERSPREADING THE REGION, ACCOMPANIED BY THE MID/HIGH
CLOUDS WE'RE SEEING ON THE IR CHANNELS. MOST OF THIS MOISTURE IS
AT OR ABOVE 700 MB, RESULTING IN CEILINGS IN AROUND 9-10 KFT. THE
00Z RAOB FROM LZK AND MEM ACARS DATA INDICATE A THERMAL PROFILE
WELL BELOW THE MELTING POINT WITH ICE CRYSTALS LIKELY BEING
SUPPLIED ABOVE THE DENDRITIC GROWTH ZONE (LAYER WHERE TEMPERATURES
ARE ROUGHLY -12 TO -18 DEGREES CELSIUS) WHICH IS ON THE COLDER
END OF THE SPECTRUM FOR GOOD DENDRITES. THIS SHOULD RESULT IN
DRY SNOWFLAKES FALLING THROUGH THE MID/UPPER-LEVELS OF THE
TROPOSPHERE OVERNIGHT.
THE VERY DRY SUBCLOUD LAYER INDICATED BY THE POINT SOUNDINGS WILL
SUBLIMATE A MAJORITY OF THIS PRECIPITATION BEFORE IT REACHES THE
SURFACE. THIS CAN BE SEEN BY THE "RETURN-FREE" AREA (CORRESPONDING
TO A RADAR BEAM HEIGHT OF 3 KFT OR LESS) SURROUNDING THE LZK
RADAR. NO ACCUMULATIONS OR IMPACTS ARE EXPECTED, BUT DON'T BE
SURPRISED TO SEE A FEW FLURRIES OVERNIGHT. THE MAIN ISSUE IS THE
VERY COLD AIRMASS SETTLED OVER THE MID-SOUTH. A REINFORCEMENT OF
THE ARCTIC AIR WILL ARRIVE LATE TONIGHT RESULTING IN GUSTY
NORTHWEST WINDS AT TIMES, AT LEAST FROM JUST BEFORE SUNRISE
THROUGH EARLY AFTERNOON. WINDS WERE RAISED SLIGHTLY DURING THIS
PERIOD, MORE IN LINE WITH THE LATEST HRRR. THAT SAID, TEMPERATURES
(AND WIND CHILL) LOOK TO REMAIN ABOVE THE COLD WEATHER ADVISORY
THRESHOLDS OVER THE NEXT 24 HOURS, SO NO HEADLINES WILL BE
INCLUDED. THE COLD AIR WILL PERSIST THROUGH MIDWEEK WITH APPARENT
TEMPERATURES POTENTIALLY APPROACHING ADVISORY CRITERIA TUESDAY
NIGHT.
MJ
SYNOPSIS
ISSUED AT 225 PM CST MON JAN 20 2025
ARCTIC AIR WILL CONTINUE OVER THE REGION THROUGH MID-WEEK. A SLOW
WARM UP WILL RETURN TEMPS TO NEAR NORMAL BY THE WEEKEND. RAIN
CHANCES RETURN FOR SATURDAY NIGHT INTO SUNDAY.
DISCUSSION
(THIS EVENING THROUGH NEXT SUNDAY)
ISSUED AT 225 PM CST MON JAN 20 2025
ARCTIC HIGH PRESSURE HAS SETTLED OVER THE REGION WITH AFTERNOON
TEMPS RANGING FROM THE UPPER TEENS ALONG THE KY BORDER TO THE
UPPER 20S OVER NORTH MS DESPITE LOTS OF SUN. WIND CHILLS ARE IN
THE TEENS.
REMINDER...THIN ICE IS FORMING ON PONDS AND SMALL BODIES OF WATER.
DURING COLD SAPS LIKE THIS KIDS FALL THROUGH THIN ICE. STAY OFF
THE ICE. IT IS NOT SAFE.
HIGH CLOUDS ARE ON THE INCREASE AS AN UPPER TROUGH APPROACHES
ALONG WITH AN ASSOCIATED REINFORCING COLD FRONT. WE ARE WATCHING A
SWATH OF LIGHT SNOW ACROSS THE SOUTHERN PLAINS THAT WILL PUSH ESE
TOWARD THE MID-SOUTH TONIGHT. LOW LEVEL MOISTURE WILL BE LACKING
BY THE TIME THIS MOISTURE ARRIVES SO MOST OF THE SNOW WILL HAVE
DISSIPATED THOUGH A FEW FLURRIES ARE POSSIBLE ACROSS PARTS OF THE
DELTA, MAINLY SW OF MEMPHIS. EXPECT ANOTHER COLD NIGHT THOUGH
CLOUDS WILL KEEP THE MERCURY FROM DIPPING TOO LOW. LOWS WILL BE
MAINLY IN THE MID AND UPPER TEENS WITH WIND CHILLS RANGING FROM 5F
NORTH TO THE LOW TO MID TEENS SOUTH.
TUESDAY WILL BE BITTERLY COLD AS SKIES CLEAR AND THAT REINFORCING
AIRMASS ARRIVES ON A BRISK NW WIND THAT WILL BE SLIGHTLY MORE
IRRITATING THAN TODAY. HIGHS WILL RANGE FROM THE LOW 20S NORTH TO
THE UPPER 20S OVER NORTH MS WITH WIND CHILLS IN THE TEENS.
TUESDAY NIGHT WILL BE VERY COLD WITH EXCELLENT RADIATIONAL
COOLING...ESPECIALLY EAST OF THE MS RIVER WHERE WINDS WILL BE
LIGHT OR CALM. LOWS WILL RANGE FROM THE SINGLE DIGITS TO MID TEENS
AND A COLD WEATHER ADVISORY MAY NEEDED FOR AT LEAST PARTS OF THE
MID-SOUTH.
TEMPERATURES START TO MODERATE WEDNESDAY AND THURSDAY AS ARCTIC
HIGH PRESSURE LOOSENS ITS GRIP THOUGH IT WILL STILL BE QUITE
CHILLY WITH HIGHS IN THE 30S ON WEDNESDAY AND 40S BY THURSDAY.
ANOTHER UPPER TROUGH PUSHING THROUGH FRIDAY WILL BRING A PARTING
SHOT OF COLD AIR AND MAYBE A FEW FLURRIES, STALLING THE WARMUP FOR
A DAY.
BY THE WEEKEND THE NORTHWEST FLOW TRANSITIONS TO THE ZONAL
VARIETY RESULTING IN MILDER, MORE NORMAL TEMPS. INCREASING
OVERRUNNING AS LOW PRESSURE DEVELOPS OVER THE NW GULF OR THE
LOWER MS VALLEY MAY RESULT IN RAIN BY SATURDAY NIGHT INTO SUNDAY.
AVIATION
(00Z TAFS)
ISSUED AT 530 PM CST MON JAN 20 2025
A SURFACE COLD FRONT WILL PUSH THROUGH ALL TERMINALS BY TOMORROW
MORNING. A FEW SNOW FLURRIES ARE POSSIBLE, BUT NO IMPACTS ARE
EXPECTED. OCCASIONAL WIND GUSTS TO 20 KTS ARE POSSIBLE THROUGH
EARLY AFTERNOON.
STRONG SURFACE HIGH PRESSURE WILL BUILD IN LATE TOMORROW NIGHT
WITH WINDS BECOMING NEARLY CALM AT ALL SITES.
AC3
MEG WATCHES/WARNINGS/ADVISORIES
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
PUBLIC FORECAST...SJM
AVIATION...AC3
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