National Weather Service Text Product Display

Area Forecast Discussion
Issued by NWS Nashville, TN

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FXUS64 KOHX 181852
AFDOHX

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

.UPDATE...FOR 18Z TAFS.

&&

.AVIATION...
LOW-LEVEL MOISTURE AND A SFC/LOW-LEVEL BOUNDARY EXPECTED TO
REMAIN IN THE IMMEDIATE VICINITY THE NEXT 24HRS. THAT WILL
CONTINUE TREND OF PERIODIC SHOWERS/STORMS. ADDITIONALLY...
CEILINGS/VSBYS EXPECTED TO DROP INTO MVFR/IFR RANGE TONIGHT
...ESPECIALLY CSV WHERE MOISTURE DEEPER AND CONVECTION EXPECTED
TO BE MORE NUMEROUS. IMPROVEMENT WILL OCCUR LATE SUN MORNING.

&&

.PREV DISCUSSION... /ISSUED 1131 AM CDT SAT MAY 18 2013/

MESOSCALE UPDATE...CELLS ARE NOW STARTING TO DEVELOP MAINLY EAST
OF I-65, WHERE LOW-LEVEL MOISTURE IS A LITTLE MORE PLENTIFUL. LAPS
SOUNDING FOR BNA VALID AT 15Z ALREADY SHOWS A LIFTED INDEX OF -3.6
AND A CONVECTIVE AVAILABLE POTENTIAL ENERGY OF 1896 J/KG. K-INDEX
IS A LITTLE LOW AT JUST 23, OWING MAINLY TO DRY AIR ABOVE ABOUT
850 MB. NAM SHOWS THE UPPER TROUGH SITUATED JUST EAST OF MIDDLE
TENNESSEE, WITH A RIDGE OF HIGH PRESSURE WEST OF THE MISSISSIPPI,
PLACING THE MID STATE UNDER A NW FLOW ALOFT, WHICH SHOULD HELP
FURTHER STEEPEN OUR MID-LEVEL LAPSE RATES. RUC MODEL SOUNDINGS FOR
THIS AFTERNOON SHOW THE LI DROPPING TO BETWEEN -5 AND -6, WITH
CAPES EXCEEDING 2500 J/KG DURING THE MOST UNSTABLE PARTS OF THE
DAY. FULLY EXPECT CONVECTION TO CONTINUE DEVELOPING. CURRENT
FORECAST OF LIKELY POP`S ALONG AND JUST WEST OF THE PLATEAU, WITH
SCATTERED POP`S ELSEWHERE, APPEARS TO BE JUSTIFIED. SPC IS KEEPING
MIDDLE TENNESSEE UNDER GENERAL THUNDERSTORMS. BELIEVE MOST
AFTERNOON STORMS WILL BE STRONG AT MOST, ALTHOUGH ISOLATED SEVERE
STORMS CERTAINLY CAN`T BE RULED OUT.

&&

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

$$

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