563
FXUS64 KMRX 211140
AFDMRX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MORRISTOWN TN
740 AM EDT THU AUG 21 2025
..NEW AVIATION
DISCUSSION
ISSUED AT 137 AM EDT THU AUG 21 2025
KEY MESSAGES:
1. CHANCES FOR SHOWERS AND STORMS WILL BE MAINLY FOCUSED FURTHER
EAST TODAY. MORE AREA-WIDE CHANCES EXIST FRIDAY THROUGH THE WEEKEND.
2. A PATTERN CHANGE IS EXPECTED NEXT WEEK WITH COOLER AND DRIER
CONDITIONS. HIGHS WILL BE IN THE 70S FOR MANY LOCATIONS WITH LOWS
DROPPING WELL INTO THE 50S.
DISCUSSION:
CURRENTLY, AN UPPER-LEVEL SHORTWAVE IS JUST TO OUR WEST AS RIDGING
RECEDES EAST WITH A WEAK FRONT MOVING INTO THE REGION. HURRICANE
ERIN IS OFF THE COASTAL CAROLINAS AND EXPECTED TO PROGRESS
NORTHEASTWARD. WITH THE APPROACHING SHORTWAVE AND BROAD
NORTHWESTERLY FLOW, THE FRONTAL BOUNDARY WILL MOVE SOUTHEAST DURING
THE DAY, BECOMING CENTERED OVER WESTERN NORTH CAROLINA. THIS WILL
LEAD TO SLIGHTLY MILDER TEMPERATURES AND REDUCED MOISTURE AND
INSTABILITY COMPARED TO YESTERDAY. RAIN CHANCES WILL LINGER BUT WILL
BE FOCUSED FURTHER EAST CLOSER TO THE BOUNDARY AND BETTER MOISTURE.
INSTABILITY WILL BE MORE LIMITED TO BELOW 1,000 J/KG BUT WITH DECENT
DCAPE VALUES REMAINING. ISOLATED FLOODING AND STRONG WIND GUSTS ARE
POSSIBLE, BUT THE ENVIRONMENT IS LESS SUPPORTIVE THAN YESTERDAY. ON
FRIDAY, THE UPPER-LEVEL SHORTWAVE WILL SHIFT SLIGHTLY EAST WITH THE
FRONT WEAKENING AS IT MOVES FURTHER SOUTH. MOISTURE AND INSTABILITY
WILL STILL BE LESS THAN YESTERDAY BUT MORE SUPPORTIVE OF AREA-WIDE
RAIN CHANCES.
HEADING INTO SATURDAY, A MORE PRONOUNCED SHORTWAVE WILL BE NOTED
OVER THE NORTHERN U.S. WITH INCREASING FRONTOGENESIS IN THE GREAT
PLAINS. THIS WILL KEEP A SIMILAR PATTERN IN THE REGION DURING THE
DAY BEFORE TROUGHING DEEPENS FURTHER WITH THE FRONT MOVING TOWARDS
THE REGION ON SUNDAY, BRINGING CONTINUED CHANCES FOR SHOWERS AND
STORMS BOTH DAYS.
SUNDAY NIGHT INTO MONDAY MORNING, THE FRONT WILL MOVE THROUGH THE
REGION WITH DEEP TROUGHING PERSISTING IN THE EASTERN U.S. THROUGH AT
LEAST THE FIRST HALF OF THE WEEK. CANADIAN HIGH PRESSURE WILL ALSO
GRADUALLY MOVE INTO THE AREA BY MID-WEEK. THE EXTENT OF TROUGHING
AND 850MB TEMPERATURES POSSIBLY DROPPING BELOW 10 CELSIUS SUGGEST
THIS WILL BE A SIGNIFICANT COOLDOWN FOR THIS TIME OF YEAR,
ESPECIALLY COMPARED TO THE PATTERN WE'VE HAD. MANY PLACES WILL SEE
HIGHS ABOUT 10 DEGREES BELOW NORMAL. OVERNIGHT LOWS COULD DROP WELL
INTO THE 50S FOR MANY AS STRONG RADIATIONAL COOLING WILL BE LIKELY
AVIATION
(12Z TAFS)
ISSUED AT 736 AM EDT THU AUG 21 2025
VFR CONDITIONS ARE FORECAST TO PREVAIL AREA-WIDE TODAY AFTER
MORNING FOG DISSIPATES BY 14Z. LIGHT NORTHERLY WINDS EXPECTED.
THERE IS AROUND A 10 PERCENT CHANCE OF VICINITY SHOWERS AT TRI DUE
TO PRECIPITATION DEVELOPING NEAR THE MOUNTAINS THIS AFTERNOON,
BUT PRECIPITATION THAT DEVELOPS IS FORECAST TO MOVE SOUTHEASTWARD
AWAY FROM TRI; THEREFORE, NO IMPACTS ARE EXPECTED FOR OUR REGION.
PRELIMINARY POINT TEMPS/POPS
CHATTANOOGA AIRPORT, TN 89 70 88 70 / 10 10 60 20
KNOXVILLE MCGHEE TYSON AIRPORT, TN 87 70 88 70 / 20 10 40 30
OAK RIDGE, TN 87 69 89 69 / 10 10 40 20
TRI CITIES AIRPORT, TN 84 66 85 66 / 40 20 30 20
MRX WATCHES/WARNINGS/ADVISORIES
NC...NONE.
TN...NONE.
VA...NONE.
SHORT TERM...
AVIATION...JB
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