650
FXUS64 KMRX 021736 AAA
AFDMRX
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE MORRISTOWN TN
1236 PM EST SUN FEB 2 2025
..NEW AVIATION
UPDATE
ISSUED AT 1024 AM EST SUN FEB 2 2025
FOG AND LOW CLOUDS HAVE HELD ON LONGER THAN FORECAST, SO THE
UPDATE WILL NEED TO ADJUST SKY GRIDS AND TEMPERATURE GRIDS, AS
MANY LOCATION WITH OVERCAST CLOUD COVER ARE RUNNING 5-10 DEGREES
COLDER THAN FORECAST. THIS WILL AFFECT FORECAST HIGHS, WHICH WILL
BE LOWERED BY A FEW DEGREES IN THE AREAS WITH MORNING CLOUDS. A
SLIGHT INCREASE IN TEMPERATURES WILL BE MADE IN AREAS ADJACENT TO
THE MOUNTAINS, WHERE A DOWNSLOPE FLOW HAS KEPT CLEAR SKIES AND
TEMPERATURES WARMER THAN FORECAST. EXPECT THAT SW WINDS WILL PICK
UP IN THE NEXT FEW HOURS, WITH GUSTS AROUND 20 MPH AT TIMES THIS
AFTERNOON IN THE CENTRAL VALLEY.
SHORT TERM
(TODAY AND TONIGHT)
ISSUED AT 126 AM EST SUN FEB 2 2025
KEY MESSAGES:
1. DENSE FOG THIS MORNING IN THE SOUTHERN/CENTRAL TN VALLEY AND
CUMBERLAND PLATEAU.
2. QUIET WEATHER AND MILD TEMPS TODAY AND TONIGHT.
DISCUSSION:
DENSE FOG HAS DEVELOPED IN THE CENTRAL/SOUTHERN TENNESSEE VALLEY
AND CUMBERLAND PLATEAU. FREEZING FOG IS POSSIBLE IN PLACES THAT
ARE AT OR BELOW FREEZING WHICH CURRENTLY INCLUDES THE UPPER
CUMBERLAND PLATEAU COUNTIES. VISIBILITY WILL START IMPROVING BY 9
AM.
IN THE UPPER LEVELS, WEAK TROUGHING OR NEARLY ZONAL FLOW WILL BE
OVER THE REGION. AT THE SURFACE, HIGH PRESSURE IS CENTERED OVER
THE EAST COAST TODAY DRIFTING INTO THE ATLANTIC TONIGHT AS LOW
PRESSURE MOVES INTO THE MIDWEST. POPS WILL BE NEAR ZERO AND SKIES
WILL BE MOSTLY SUNNY/CLEAR TODAY AND TONIGHT. WINDS WILL BECOME
SOUTHERLY TODAY WITH GUSTS UP TO 20 MPH IN THE TENNESSEE VALLEY
AND 30 MPH IN THE HIGHER ELEVATIONS AND FOOTHILLS OF THE EAST
TENNESSEE MOUNTAINS AS THE 850MB WINDS INCREASE THIS AFTERNOON
WHEN CLEARING CLOUDS WILL ALLOW FOR GOOD MIXING. THERE MAY BE
ENOUGH RESIDUAL MOISTURE TONIGHT FOR ANOTHER ROUND OF PATCHY FOG.
LONG TERM
(MONDAY THROUGH SATURDAY)
ISSUED AT 126 AM EST SUN FEB 2 2025
KEY MESSAGES:
1. UNSEASONABLY WARM NEXT WEEK, ESPECIALLY MONDAY THROUGH THURSDAY.
2. RAIN CHANCES RETURN TO THE REGION FOR THE SECOND HALF OF THE
WEEK.
DISCUSSION:
FOR THE MAJORITY OF THE EXTENDED PERIOD, UPPER-LEVEL ATMOSPHERIC
FLOW WILL EXHIBIT A QUASI-ZONAL PATTERN, INTERRUPTED AT TIMES BY FAST
MOVING SHORTWAVES ACROSS THE TENNESEE AND OHIO VALLEYS. MULTIPLE JET
STREAKS TRAVERSING THE OHIO AND TENNESSEE VALLEYS LOOK LIKE THEY'LL
INDUCE CONVECTION COMMENCING FROM WEDNESDAY AND PERSISTING THROUGH
SATURDAY.
MONDAY AND TUESDAY:
PREDOMINANTLY DRY CONDITIONS. A FRONTAL BOUNDARY
WITH LIMITED MOISTURE AVAILABILITY IS FORECASTED TO APPROACH
SOUTHWEST VIRGINIA BY LATE TUESDAY. THERE EXISTS A SMALL CHANCE OF
ISOLATED SHOWERS... HOWEVER, CONFIDENCE REMAINS TOO LOW TO INCLUDE
THIS IN THE FORMAL FORECAST. EXPECT THE UNSEASONABLY WARM
TEMPERATURES TO BEGIN MONDAY WITH HIGHS LOOKING TO CLIMB INTO THE
60'S AND 70'S FOR MUCH OF THE SOUTHERN APPALACHIANS.
WEDNESDAY THROUGH THURSDAY EVENING:
THE FRONTAL BOUNDARY IS EXPECTED TO BECOME QUASI-STATIONARY OVER THE
REGION. SUCCESSIVE JET STREAKS TRAVERSING THE OHIO AND TENNESSEE
VALLEYS WILL ENHANCE FRONTOGENETIC FORCING ALONG THIS BOUNDARY,
RESULTING IN INTERMITTENT SHOWERS AND THUNDERSTORMS. ENSEMBLE CAPE
VALUES AROUND 500 J/KG SUGGEST THE POTENTIAL FOR EMBEDDED
THUNDERSTORMS. ADDITIONALLY, PRECIPITABLE WATER VALUES WILL RISE TO
1-2 STANDARD DEVIATIONS ABOVE THE SEASONAL NORMALS, WHICH INCREASES
THE THREAT FOR LOCALIZED HEAVY RAINFALL ASSOCIATED WITH THE
THUNDERSTORMS. HOWEVER, NBM'S 24-HOUR PROBABILITIES FOR
PRECIPITATION EXCEEDING 1 INCH REMAIN AT ONLY 40-50% FOR SOUTHWEST
VIRGINIA. WIDESPREAD FLOODING STILL APPEARS LOW AT THIS TIME, BUT
WITH THE EMBEDDED THUNDERSTORMS WE COULD SEE SOME ISOLATED FLOODING
OF PLACES THAT SEE MULTIPLE ROUNDS OF STORMS.
FRIDAY AND SATURDAY:
A SMALL BREAK IN CONVECTION IS ANTICIPATED AS THE JET STREAK
MIGRATES EASTWARD. FORECAST CONFIDENCE REGARDING THE TIMING OF THESE
WAVES IS LOW. ANOTHER JET STREAK IS PROJECTED TO INTENSIFY SOUTHERLY
BOUNDARY LAYER FLOW, LEADING TO AN INCREASED LIKELIHOOD OF
CONVECTION.
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
(18Z TAFS)
ISSUED AT 1234 PM EST SUN FEB 2 2025
WINDS ARE EXPECTED TO BECOME GUSTY AT TYS SOON, AND GUST UP TO 20
KT FOR A FEW HOURS UNTIL AROUND 22Z. CLEAR SKIES AND LIGHT WINDS
WILL PREVAIL OVERNIGHT EXCEPT AT TYS, WHERE FOG IS AGAIN EXPECTED
TO DEVELOP. CONFIDENCE ON FOG IS LOWER FOR TONIGHT AS WINDS MAY
STAY UP JUST ENOUGH TO PREVENT DENSE FOG DEVELOPMENT LIKE LAST
NIGHT. WILL HAVE A FEW HOURS OF MVFR PREDOMINANT VIS WITH A TEMPO
FOR IFR.
PRELIMINARY POINT TEMPS/POPS
CHATTANOOGA AIRPORT, TN 64 43 69 49 / 0 0 0 0
KNOXVILLE MCGHEE TYSON AIRPORT, TN 61 41 68 50 / 0 0 0 0
OAK RIDGE, TN 59 41 66 48 / 0 0 0 0
TRI CITIES AIRPORT, TN 59 37 64 46 / 0 0 0 0
MRX WATCHES/WARNINGS/ADVISORIES
NC...NONE.
TN...NONE.
VA...NONE.
SHORT TERM...DGS
AVIATION...DGS
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