487
FXUS64 KMRX 040310
AFDMRX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MORRISTOWN TN
1010 PM EST MON FEB 3 2025
..NEW UPDATE
UPDATE
ISSUED AT 952 PM EST MON FEB 3 2025
GOES-16 NIGHTTIME MICROPHYSICS IMAGERY SHOWS LOW-LEVEL CLOUDS
BEGINNING TO SPREAD INTO N KY WITH THE SURFACE FRONT & NORTHERLY
WIND SHIFT LAGGING SLIGHTLY BEHIND. CLOUDS CAN BE EXPECTED TO
INCREASE ACROSS OUR AREA SHORTLY AFTER MIDNIGHT. MAIN EVENING
ADJUSTMENT WAS BUMPING DOWN DEWPOINTS TO THE NBM10TH PERCENTILE TO
BETTER ALIGN WITH LATEST OBSERVATIONS. OTHERWISE, THE FORECAST
AND KEY MESSAGES REMAIN ON TRACK.
SHORT TERM
(THIS EVENING THROUGH TUESDAY)
ISSUED AT 300 PM EST MON FEB 3 2025
KEY MESSAGES:
1. CLOUDS SPREAD INTO THE AREA OVERNIGHT AHEAD OF A COLD FRONT,
SLIGHT CHANCE OF LIGHT SHOWERS/SPRINKLES IN MOUNTAINS AND SW VA.
2. DECREASING CLOUDS WITH MILD AFTERNOON TEMPERATURES ON TUESDAY.
DISCUSSION:
A COLD FRONT THAT IS CURRENTLY LOCATED NEAR THE SOUTHERN GREAT LAKES
WILL SLOWLY DRIFT SOUTHWARD THROUGH TONIGHT. AT 850 MB, THE THERMAL
GRADIENT WILL PUSH SOUTH FASTER THAN THE SURFACE FRONT, PRODUCING
COOLING AND SATURATION AT THAT LEVEL UNDERNEATH AN STRONG INVERSION.
THIS WILL RESULT IN BROKEN TO OVERCAST CLOUD FOR MOST OF THE AREA,
DEVELOPING AFTER MIDNIGHT. 850 MB WINDS WILL SHIFT TO A NW
DIRECTION, AND WITH THIS UPSLOPE FLOW, SOME NW FACING SLOPES COULD
SEE SOME LIGHT RAIN OR SPRINKLES. MOST OF THIS WILL BE TOO LIGHT TO
MEASURE, BUT A SLIGHT CHANCE POP WILL BE INCLUDED FOR THE TN
MOUNTAINS AND PARTS OF SW VA. MODELS MAY BE ERODING THE CLOUDS OUT
TOO FAST IN THE AFTERNOON GIVEN THE STRONG INVERSION ALOFT AND LOW
LEVEL MOISTURE TRAPPED AGAINST THE MOUNTAINS. WILL KEEP BROKEN CLOUD
COVER IN THE SKY GRIDS INTO THE AFTERNOON AND TAKE A DEGREE OR TWO
OFF THE NBM FORECAST HIGH TEMPS, WHICH WILL STILL PUT MOST OF THE
TN VALLEY IN THE 60S FOR HIGHS.
LONG TERM
(TUESDAY NIGHT THROUGH NEXT MONDAY)
ISSUED AT 300 PM EST MON FEB 3 2025
KEY MESSAGES:
1. UNSEASONABLY WARM THIS WEEK WITH HIGHS MAINLY IN THE 60S TO
LOWERS 70S IN THE TENNESSEE VALLEY.
2. RAIN CHANCES RETURN WEDNESDAY INTO THE WEEKEND.
3. LOCALLY HEAVY RAIN POSSIBLE WEDNESDAY NIGHT AND AGAIN THURSDAY
NIGHT ACROSS NORTHERN SECTIONS OF THE FORECAST AREA. THERE IS A
CHANCE OF LOCALIZED FLOODING OVER SOUTHWEST VIRGINIA. MORE RAIN WITH
A SLOW MOVING BOUNDARY SATURDAY INTO SUNDAY.
4. COOLER SUNDAY INTO MONDAY. NEAR AVERAGE TEMPERATURES MONDAY. A
CHANCE OF SNOW SUNDAY NIGHT AND EARLY MONDAY.
DISCUSSION:
STARTING FROM TUESDAY NIGHT IN THE UPPER LEVELS WEAK RIDGING WILL BE
OVER THE SOUTHEAST AND A TROUGH WILL BE EXITING THE NORTHEAST
STATES. THE UPPER FLOW WILL BE MOSTLY ZONAL. AT THE SURFACE, TUESDAY
NIGHT HIGH PRESSURE WILL BE OVER THE SOUTHEAST AND A COLD HIGH
PRESSURE AREA WILL BE OVER THE NORTHERN PLAINS, GREAT LAKES AND
NORTHERN OHIO VALLEY.
A WEAK FRONTAL BOUNDARY WILL LIKELY BE SOUTH OF THE FORECAST AREA
BUT IT IS EXPECTED TO MOVE BACK NORTH AS A WARM FRONT LATER WEDNESDAY
INTO THURSDAY. A SHORTWAVE TROUGH WILL MOVE THROUGH THE PATTERN WEDNESDAY
NIGHT. LOW PRESSURE DEVELOPS ALONG A COLD FRONT OVER OKLAHOMA THURSDAY MORNING
AS THE EASTERN PART OF THE FRONT MOVES INTO THE OHIO VALLEY. ANOTHER SURFACE
LOW OVER THE GREAT LAKES WILL BRINGS A COLD FRONT THROUGH THE REGION
THURSDAY NIGHT. THE HIGHEST RAINFALL AMOUNTS ARE NOW EXPECTED TO BE UP TO
ABOUT 1 INCH THROUGH THURSDAY NIGHT. SOUTHWEST VIRGINIA COULD HAVE A
RISK FOR FLOODING WITH THE RAINFALL THEY RECEIVED A COUPLE DAYS AGO.
THERE IS STILL UNCERTAINTY OF THE BOUNDARY LOCATIONS DURING THIS
TIME PERIOD.
FRIDAY AND THROUGH THE WEEKEND THE NEAR ZONAL FLOW WILL CONTINUE IN
THE UPPER LEVELS. MORE LOW PRESSURE DEVELOPING TO THE WEST ALONG A
FRONTAL BOUNDARY IS EXPECTED TO MOVE ACROSS SATURDAY THROUGH SUNDAY.
THIS SYSTEM WILL INCREASE RAIN CHANCES AGAIN NORTHERN AREAS SATURDAY
AND THEN THE REST OF THE REGION SUNDAY. THE SLOW MOVEMENT COULD BRING
ANOTHER INCH OF RAIN TO SOUTHWEST VIRGINIA WHICH WOULD ENHANCE FLOODING
RISK AGAIN. IT LOOKS LIKE LOWER AMOUNTS IN THE SOUTHERN PART OF THE AREA.
TEMPERATURES WILL STAY MILD WEDNESDAY THROUGH SATURDAY AND BE MUCH
ABOVE NORMAL. THE WARMEST DAYS WILL BE THURSDAY AND SATURDAY WITH
HIGHS IN THE 60S TO LOWER 70S. IT STILL LOOKS LIKE THE BEST CHANCE
FOR BREAKING THE RECORD HIGHS COULD BE THURSDAY AND ALSO SATURDAY.
CLOUD COVER AND INCREASING RAIN CHANCES THOUGH WILL AFFECT TEMPERATURES
SO STILL NOT SURE.
THE SECOND SYSTEM WILL BRING IN A MUCH COLDER AIRMASS SUNDAY NIGHT
AND MONDAY WITH LOWS IN THE UPPER 20S AND 30S AND A CHANCE OF RAIN
AND SNOW SHOWERS. HIGHS MONDAY WILL BE BACK TO NEAR AVERAGE TO
SLIGHTLY BELOW AVERAGE IN THE 40S TO THE LOWER 50S.
DAILY RECORD HIGH MAXIMUM TEMPERATURES
DATE CHATTANOOGA KNOXVILLE TRI-CITIES OAK RIDGE
02-05 75(1890) 73(2008) 71(2008) 71(2019)
02-06 70(2019) 73(1986) 68(1991) 70(2008)
02-07 80(2019) 77(2019) 76(2019) 76(2019)
02-08 76(1937) 75(1937) 70(2001) 71(2009)
AVIATION
(00Z TAFS)
ISSUED AT 637 PM EST MON FEB 3 2025
AN APPROACHING COLD FRONT WILL BRING A LOWERING CLOUD DECK TO THE
REGION OVERNIGHT AND INTO TUESDAY. MVFR CONDITIONS ARE EXPECTED AT
ALL SITES BY THE EARLY TO MID MORNING TIME FRAME. REDUCED CEILINGS
ARE EXPECTED TO CONTINUE INTO AT LEAST THE EARLY AFTERNOON, BUT MY
PERSIST INTO THE EVENING AT TRI AND TYS. UNCERTAINTY IS HIGHER
REGARDING HOW LONG THE CIGS WILL PERSIST. LIGHT WINDS WILL VEER
NORTHERLY BEHIND THE FRONTAL PASSAGE TOMORROW AFTERNOON AS WELL.
PRELIMINARY POINT TEMPS/POPS
CHATTANOOGA AIRPORT, TN 51 70 54 70 / 0 0 0 30
KNOXVILLE MCGHEE TYSON AIRPORT, TN 51 65 49 68 / 0 0 0 40
OAK RIDGE, TN 49 65 48 66 / 0 0 10 40
TRI CITIES AIRPORT, TN 46 59 43 60 / 10 10 0 30
MRX WATCHES/WARNINGS/ADVISORIES
NC...NONE.
TN...NONE.
VA...NONE.
SHORT TERM...DGS
LONG TERM....TD
AVIATION...KRS
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