National Weather Service Weather Forecast Office

Area Forecast Discussion

646
FXUS64 KOHX 190450
AFDOHX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NASHVILLE TN
1150 PM CDT SAT MAY 18 2013

.AVIATION UPDATE...FOR 06Z TAF PACKAGE...
CONTINUE TO SEE VCTS AT KCSV WITH STORMS DEVELOPING ALONG TROUGH
AXIS DRAPED JUST SOUTH OF THE TERMINAL. SHOULD CONTINUE ANOTHER
COUPLE HOURS AFTER ISSUANCE. LIGHT FOG ALREADY IMPACTING KCSV AS
WELL. INTRODUCE BR AT ALL TERMINALS IN FIRST THREE HOURS OF TAF
PERIOD. DO NOT THINK BR WILL BE AS THICK AS PREVIOUS NIGHT DUE TO
CLOUD COVER AND OUTFLOWS FROM AFTERNOON CONVECTION BRING LIGHT
WIND SHIFTS. MODELS SUGGEST PRECIP TO INCREASE ACROSS ALL
TERMINALS BEGINNING AROUND 18Z. INCLUDED VCTS AT THIS TIME TO
REFLECT THIS CHANGE.

&&

.PREV DISCUSSION... /ISSUED 648 PM CDT SAT MAY 18 2013/

UPDATE...
PER CURRENT REGIONAL SFC OBS...SATELLITE IMAGERY...RADAR MOSAICS...
AND SHORT TERM MODEL CONSENSUS HAVE UPDATED THE SUITE OF FORECAST
PRODUCTS TO REFLECT VARIABLE CLOUDINESS ACROSS THE MID STATE THRU
THE REMAINDER OF TONIGHT ALONG WITH A SLIGHT CHANCE OF SHWRS/TSTMS...
EXPECT PLATEAU WHERE A CHANCE SHOULD PERSIST PER UPPER LEVEL TROUGHING
INFLUENCES. WILL CONTINUE WITH PATCHY FOG MENTION AFTER MIDNIGHT TOO...
BUT OVERALL DO NOT ANTICIPATE AS MUCH PATCHY FOG AS DEVELOPED THIS
MORNING. CURRENT TEMPS IN LINE WITH FORECASTED LOWS AND THUS CHANGES
WERE NOT MADE.

PREV DISCUSSION.../ISSUED 626 PM CDT SAT MAY 18 2013/

AVIATION UPDATE...FOR 00Z TAF PACKAGE...
DIALED BACK BR CONCERNS A BIT FOR THE NEXT 12 HOURS DUE TO PEAK
HEATING DEWS BEING LOWER THAN GUIDANCE SUGGESTED. STILL THINK BR
WILL BE POSSIBLE FOR ALL THREE TERMINALS...BUT JUST IMPROVED
FORECAST VISIBILITIES TO BE A LITTLE LESS SIGNIFICANT. CURRENT
RADAR ONLY SHOWS ISOLATED CONVECTION IN VICINITY OF KCSV SO
REMOVED VICINITY MENTION IN KBNA AND KCKV. BELIEVE THERE IS ENOUGH
DRY AIR ALOFT TO PREVENT ANY MORE DEVELOPMENT AFTER NIGHTFALL.
ALTHOUGH MODELS ARE SUGGESTING DEVELOPMENT OVERNIGHT SO AMENDMENTS
MAY BE NEEDED IF THIS IS REALIZED.

PREV DISCUSSION... /ISSUED 157 PM CDT SAT MAY 18 2013/

DISCUSSION...SCATTERED CONVECTION GOING ON EAST OF NASHVILLE THIS
AFTERNOON WHERE LOW-LEVEL MOISTURE IS MOST ABUNDANT. UPPER
TROUGH REMAINS STALLED OUT JUST TO OUR EAST, SO LOOK FOR THIS
PATTERN TO PERSIST AS TEMPERATURES CONTINUE TO RISE AND THE
ATMOSPHERE REMAINS AT LEAST MODERATELY UNSTABLE. LOOK FOR THE MID
STATE TO FINALLY DRY OUT SUNDAY NIGHT, WITH THE UPPER RIDGE MOVING
ACROSS THE AREA ON MONDAY, THEREBY PAVING THE WAY FOR THE NEXT
ACTIVE WEATHER SYSTEM TO CLOSE IN ON MIDDLE TENNESSEE TOWARD THE
MIDDLE OF THE WEEK. THERE WILL BE A SLIGHT DROP-OFF IN
TEMPERATURES FOLLOWING THIS COLD FRONTAL PASSAGE, BUT EVEN OUR
POST-FRONTAL READINGS LATE IN THE WEEK WON`T BE TOO FAR OFF
SEASONAL NORMALS. AT THIS TIME, THE SPC HAS NO SEVERE WEATHER RISK
AREAS PEGGED FOR MIDDLE TENNESSEE THROUGH DAY 8, SO WE ARE
EXPECTING GENERAL THUNDERSTORMS ONLY.

&&

.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

TB12