190
FXUS64 KMRX 020535
AFDMRX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MORRISTOWN TN
1235 AM EST SUN FEB 2 2025
..NEW AVIATION
UPDATE
ISSUED AT 949 PM EST SAT FEB 1 2025
OVERALL, MINIMAL CHANGES WERE MADE WITH THE EVENING UPDATE. RIVER
FLOOD PRODUCTS REMAIN IN EFFECT FOR THE POWELL RIVER, NORTHERN
CLINCH RIVER, AND THE NORTH FORK OF THE HOLSTON RIVER. BASED ON
THE LATEST DATA, THE RIVER LEVELS ARE STILL LARGELY ON TRACK WITH
PREVIOUS FORECASTS. ALSO, TEMPERATURES THIS EVENING HAVE FALLEN A
BIT QUICKER THAN EXPECTED, SO THEY WERE REDUCED OVER THE NEXT
COUPLE OF HOURS. THIS HAS ALSO DECREASED THE DEW POINT DEPRESSIONS
IN MANY PLACES. THIS CONTINUES TO INCREASE CONFIDENCE IN
DEVELOPMENT OF AT LEAST PATCHY DENSE FOG, ESPECIALLY IN RIVER
VALLEYS AND FURTHER SOUTH WHERE THE AIR WILL BE LESS DRY. IT ALSO
DEPENDS ON HOW MUCH LINGERING CLOUD COVER CONTINUES TO DIMINISH.
SHORT TERM
(THIS EVENING THROUGH SUNDAY)
ISSUED AT 230 PM EST SAT FEB 1 2025
KEY MESSAGES:
1. DENSE FOG POSSIBLE TONIGHT AND SUNDAY MORNING IN THE SOUTHERN AND
CENTRAL TN VALLEY.
2. MOSTLY SUNNY AND MILD SUNDAY AFTERNOON.
DISCUSSION:
PERSISTENT CLOUD COVER THIS MORNING IS STARTING TO SHOW SIGNS OF
EROSION FROM THE NORTH AS A WEAK COLD FRONT DRIFTS SOUTHWARD. WINDS
HAVE SHIFTED TO NORTH ACROSS MOST OF THE AREA, SO THIS CLEARING
TREND SHOULD CONTINUE THROUGH THE EVENING, WITH COUNTIES AGAINST THE
MOUNTAINS BEING SLOWEST TO CLEAR/SCATTER OUT. MODEL GUIDANCE
(NAMNEST, HRRR, LAMP IS STRONGLY SUGGESTING FOG DEVELOPMENT TONIGHT
IN THE CENTRAL AND SOUTHERN VALLEY WITH VISIBILITY OF A QUARTER
MILE OR LESS FROM KNOXVILLE TO CHATTANOOGA. AT TRI-CITIES, THERE
WILL BE A LITTLE BETTER PRESSURE GRADIENT AND DOWNSLOPE FLOW AS
HIGH PRESSURE OVER THE MID-ATLANTIC EXTENDS SW ALONG THE BLUE
RIDGE. THE FOG FORMATION WILL BE DEPENDENT ON THE MODELS
ACCURATELY DEPICTING THE CURRENT CLOUD COVER CLEARING OUT THIS
EVENING.
ON SUNDAY WE WILL HAVE A GOOD SW UP-VALLEY FLOW AS LOW PRESSURE
TRACKS INTO THE GREAT LAKES AND HIGH PRESSURE CONTINUES TO EXTEND SW
ACROSS THE CAROLINAS AND GEORGIA, WITH A NEARLY ZONAL FLOW THROUGH
THE MID AND UPPER LEVELS. SW WINDS MAY BE GUSTY AT TIMES, UP TO 20
MPH WITH AFTERNOON MIXING AND CHANNELING THROUGH THE VALLEY. THIS
SHOULD WARM TEMPERATURES UP INTO THE UPPER 50S TO MID 60S FOR MOST
LOCATIONS, WHICH IS ABOUT 8-12 DEGREES ABOVE NORMAL FOR THE DATE.
LONG TERM
(SUNDAY NIGHT THROUGH NEXT SATURDAY)
ISSUED AT 230 PM EST SAT FEB 1 2025
KEY MESSAGES:
1. UNSEASONABLY WARM NEXT WEEK, ESPECIALLY MONDAY THROUGH THURSDAY,
WITH HIGHS 15-20 DEGREES ABOVE NORMAL.
2. DRY THROUGH THE FIRST HALF OF NEXT WEEK, WITH RAIN CHANCES
RETURNING WEDNESDAY THROUGH FRIDAY.
DISCUSSION:
FOR MOST OF THE EXTENDED PERIOD, THE UPPER FLOW WILL BE ZONAL ACROSS
THE NATION WITH A FAST WEST TO EAST MOVEMENT OF SHORT-WAVES. A
SERIES OF JET STREAKS MOVING ACROSS THE OHIO AND TENNESSEE VALLEYS
WILL PRODUCE CONVECTION BEGINNING WEDNESDAY THROUGH SATURDAY.
FOR MONDAY AND TUESDAY, MOSTLY DRY. A MOISTURE STARVED FRONTAL
BOUNDARY WILL APPROACH SOUTHWEST VIRGINIA LATE IN THE DAY TUESDAY.
LOW CHANCE OF A SHOWER BUT CONFIDENCE TOO LOW TO INCLUDE IN
THE FORECAST. UNSEASONABLY WARM.
FOR WEDNESDAY THROUGH THURSDAY EVENING, THIS FRONTAL BOUNDARY
BECOMES QUASI-STATIONARY OVER THE AREA. SERIES OF JET STREAKS MOVING
ACROSS THE OHIO AND TENNESSEE VALLEYS WILL INCREASE THE FRONTO-
GENETIC FORCING ALONG THIS BOUNDARY TO PRODUCE PERIODS OF SHOWERS
AND THUNDERSTORMS. ENSEMBLE CAPE OF 500 J/KG WILL PRODUCE EMBEDDED
THUNDERSTORMS. NAEFS SHOWS PWS INCREASING TO 1 TO 2 STANDARD
DEVIATIONS ABOVE NORMAL SO SOME LOCALLY HEAVY RAINS POSSIBLE.
HOWEVER, NBM 24 HOURS PROBABILITIES OF 1 INCH OR MORE OF RAIN IS
ONLY UP TO 40-50 PERCENT ACROSS SOUTHWEST VIRGINIA. AT THIS TIME,
FLOODING POTENTIAL IS LOW BUT NEEDS TO BE WATCHED.
A BREAK IN THE CONVECTION IS POSSIBLE FRIDAY AS THE JET STREAK MOVES
EAST OF THE AREA. CONFIDENCE IS LOW ON THE TIMING OF THESE WAVES.
FOR SATURDAY, ANOTHER JET STREAK INCREASES THE SOUTHERLY BOUNDARY
LAYER FLOW WITH ANOTHER INCREASING CHANCE OF CONVECTION.
AGAIN, OVERALL A VERY MILD PATTERN WITH PERIODS OF RAIN FOR THE
EXTENDED PERIOD.
DAILY RECORD HIGH MAXIMUM TEMPERATURES
DATE CHATTANOOGA KNOXVILLE TRI-CITIES OAK RIDGE
02-02 76(2016) 75(2016) 71(1989) 74(2016)
02-03 75(1986) 74(2020) 74(1989) 71(2020)
02-04 77(1927) 72(1986) 68(1986) 68(1992)
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)
AVIATION
(06Z TAFS)
ISSUED AT 1224 AM EST SUN FEB 2 2025
FOG IS ALREADY DEVELOPING IN THE CENTRAL AND SOUTHERN TENNESSEE
VALLEY. TYS IS ALREADY REPORTING VIS RESTRICTIONS. CHA AND TYS
WILL LIKELY HAVE VIS RESTRICTIONS THROUGH MID MORNING WITH
SIGNIFICANT IMPROVEMENT EXPECTED BY 9 AM. OTHERWISE, VFR
CONDITIONS ARE EXPECTED. WINDS WILL BECOME SOUTHERLY TODAY AND MAY
BE GUSTY AT TIMES ESPECIALLY NEAR TYS.
PRELIMINARY POINT TEMPS/POPS
CHATTANOOGA AIRPORT, TN 64 43 70 49 / 0 0 0 0
KNOXVILLE MCGHEE TYSON AIRPORT, TN 62 40 68 49 / 0 0 0 0
OAK RIDGE, TN 60 42 66 48 / 0 0 0 0
TRI CITIES AIRPORT, TN 57 36 64 44 / 0 0 0 0
MRX WATCHES/WARNINGS/ADVISORIES
NC...NONE.
TN...NONE.
VA...NONE.
SHORT TERM...DGS
LONG TERM....DH
AVIATION...MCD
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