397
FXUS64 KMRX 180655
AFDMRX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MORRISTOWN TN
255 AM EDT SAT APR 18 2026
..NEW DISCUSSION
KEY MESSAGES
UPDATED AT 254 AM EDT SAT APR 18 2026
- SHOWERS AND STORMS WILL MOVE INTO THE AREA THROUGH THIS EVENING WITH
SOME STRONG TO MARGINALLY SEVERE STORMS POSSIBLE. DAMAGING
WINDS AND HAIL ARE THE MAIN CONCERNS, ESPECIALLY ALONG AND NORTH
OF INTERSTATE 40.
- DRIER AND MUCH COOLER CONDITIONS ARE EXPECTED SUNDAY INTO MONDAY
WITH LOW RH'S IN THE 20S AND LOWER 30S RETURNING.
- DRY CONDITIONS WILL CONTINUE THROUGH THE WEEK, ALONG WITH A
GRADUAL WARMING TREND. LOW RH'S CONTINUE TO BE OF CONCERN.
DISCUSSION
ISSUED AT 254 AM EDT SAT APR 18 2026
CURRENTLY, A TROUGH/UPPER JET IS CENTERED TO OUR NORTHWEST WITH A
SURFACE LOW MOVING INTO ONTARIO, CANADA. THIS SETUP HAS PRODUCED A
BROAD WARM SECTOR AND LARGE-SCALE SEVERE WEATHER EVENT WITH A COLD
FRONT EXTENDING ALONG AND WEST OF THE MISSISSIPPI RIVER. THIS COLD
FRONT WILL APPROACH THE AREA THROUGHOUT THE DAY TODAY WITH
INCREASING SOUTHERLY FLOW OUT AHEAD. SHOWERS AND STORMS, SOME
DISCRETE, ARE EXPECTED DURING THE EVENING HOURS AHEAD OF THIS FRONT.
THE FOCUS FOR STRONG TO MARGINALLY SEVERE STORMS CONTINUES TO BE IN
THE NORTHERN HALF OF THE REGION WHERE MLCAPE OF NEAR 1,000 J/KG IS
SUGGESTED DUE TO BETTER HEIGHT FALLS. WHILE STRONGER FLOW IS
EXPECTED ALOFT, 850MB WINDS WILL REMAIN GENERALLY 30 KTS OR LESS
WITH LIMITED LOW-LEVEL SHEAR. CAPE WITHIN THE -10 TO -30 CELSIUS
REGION IS INDICATED TO BE NEAR 400 J/KG WITH WBZ HEIGHTS AROUND
10,000 FEET. THIS CONTINUES TO SUGGEST LOW-END THREATS FOR DAMAGING
WINDS AND HAIL, AS SHOWN IN THE OUTLOOK. THE COLD FRONT WILL MOVE
THROUGH THE AREA AFTER MIDNIGHT, LEADING TO DECREASING RAIN COVERAGE.
THROUGHOUT THE DAY ON SUNDAY, THE COLD FRONT WILL HAVE PUSHED WELL
OFF TO THE EAST WITH HIGH PRESSURE EXPANDING FROM THE SOUTHWEST.
THIS WILL LEAD TO COOLER AND DRIER CONDITIONS WITH HIGH TEMPERATURES
REMAINING IN THE 60S FOR MOST. LOW RH'S IN THE 20S WILL COME BACK
INTO VIEW, ALONG WITH NORTHWESTERLY WINDS. SUNDAY NIGHT WILL BE
NOTABLY COOLER FOLLOWING RECENT SUBSIDENCE WITH SOME PLACES DROPPING
INTO THE 30S. BY MONDAY, HIGH PRESSURE WILL BE CENTERED NEARBY,
LEADING TO A WEAKER MSLP GRADIENT/WINDS BUT CONTINUED DRY
CONDITIONS. EVEN COOLER LOW TEMPERATURES CAN BE EXPECTED MONDAY
NIGHT, POTENTIALLY COLD ENOUGH FOR FROST IN SOME AREAS. BY TUESDAY,
RECENT TROUGHING AND SURFACE HIGH PRESSURE WILL SHIFT OFF TO THE
EAST, PRODUCING A SHIFT TO SOUTHERLY FLOW AND HEIGHT RISES. THIS
WILL BEGIN ANOTHER WARMING TREND WITH HIGHS RISING BACK ABOVE
NORMAL. RIDGING WILL LEAD TO FURTHER HEIGHT RISES THROUGH THE END OF
THE WEEK WITH MOST PLACES RISING BACK INTO THE 80S. LOW RH'S WILL
CONTINUE TO BE OF CONCERN WITH GENERALLY SOUTHERLY TO SOUTHWESTERLY
FLOW. WITH A FAIRLY WEAK MSLP GRADIENT AND 850MB FLOW, WIND GUSTS
WILL BE GENERALLY 15 TO 20 MPH OR LESS FOR MOST AREAS.
AVIATION
(06Z TAFS)
ISSUED AT 151 AM EDT SAT APR 18 2026
VFR AND DRY CAN GENERALLY BE EXPECTED FOR THE FIRST THREE QUARTERS
OF THE TAF PERIOD. SW WINDS WILL INCREASE OUT AHEAD OF A FRONTAL
PASSAGE LATER THIS MORNING AND AFTERNOON. GUSTS UP TO 25KT
POSSIBLE AT TYS.
WX AND WIND DIRECTION CHANGE EXPECTED AROUND THE LAST 6 HOURS OF
THE TAF. WIND DIRECTION TO EVENTUALLY TURN OUT OF THE NW. SHOWERS
WITH THE FRONT WILL APPROACH AND CROSS THE AREA THIS EVENING AND
PART OF THE OVERNIGHT HOURS. LOW CHANCES FOR TS, SO DO NOT HAVE
ANYTHING MENTIONED, ALTHOUGH IT'S A NON ZERO CHANCE. DEGRADATION
TO MVFR CIG AND VSBY POSSIBLE WITH THE FRONT.
PRELIMINARY POINT TEMPS/POPS
CHATTANOOGA AIRPORT, TN 88 48 69 43 / 20 90 10 0
KNOXVILLE MCGHEE TYSON AIRPORT, TN 85 47 64 43 / 20 90 10 0
OAK RIDGE, TN 85 45 66 42 / 40 90 10 0
TRI CITIES AIRPORT, TN 84 45 61 39 / 20 90 20 0
MRX WATCHES/WARNINGS/ADVISORIES
NC...NONE.
TN...NONE.
VA...NONE.
DISCUSSION...BW
AVIATION...KS
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