Flash Flood Warning 20, NWS Nashville, TN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NASHVILLE TN
1030 PM CDT SUN MAY 16 2010

.MESOSCALE UPDATE...
MERGING CELLS APPROACHING NORTHWEST WAYNE COUNTY AT 0326Z. FFMP
SHOWING HEAVY RAINFALL RATES ACROSS NORTHWEST WAYNE CO FROM CLIFTON
TO ROSS CREEK LANDING. EXPECT THIS TO CONTINUE AND MOVE EAST NEXT
HALF HOUR. FFMP SHOWING RAINFALL RATES AROUND 2 INCHES PER HOUR THESE
AREAS. WILL CONTINUE TO MONITOR CLOSELY.

BOYD

&&

.PREV DISCUSSION... /ISSUED 912 PM CDT SUN MAY 16 2010/

UPDATE...
WILL BUMP UP POPS FOR FAR WESTERN ZONES WITH AREA OF CONVECTION
OVER WRN TN HOLDING TOGETHER AS IT PUSHES E. COULD BE SOME HEAVY
RAINS IN ISOLATED AREA...JUST WHAT WE DON'T NEED.

MAG

PREV DISCUSSION... /ISSUED 804 PM CDT SUN MAY 16 2010/

MESOSCALE UPDATE...
BEEN KEEPING TABS ON QUASI-LINEAR MCS MOVING EASTWARD AROUND 30KTS
THROUGH WESTERN TN AND NORTHERN MS. LINE OF STORMS IN NORTHERN MS
SHOWING BOWING WITH GOOD DRYING BEHIND BOW. THIS HAS BEEN TRACKING
DUE EAST WITH CONSISTENCY SO EXPECT THIS FEATURE TO STAY SOUTH OF
MID STATE. MUCAPE OF 2000 J/KG NOW ACROSS WEST TN DOWN AND INTO
NORTHEAST MS AHEAD OF LINE. 17/00Z OHX RAOB SHOWING PRECIPITABLE
WATER AT 1.68 INCHES WITH MILLERS TOTAL TOTALS AT 51. OHX SOUNDING
HAS BOGUS DATA NEAR SURFACE (VERY LARGE SUPERADIABATIC LAPSE RATE).
SHOWERS AND STORMS WILL NOT FIND AS MUCH INSTABILITY TO WORK WITH
AS THEY MOVE INTO WESTERN MIDDLE TN LATER THIS EVENING...BUT LOCALLY
HEAVY RAINFALL AND GUSTY WINDS STILL POSSIBLE WITH THESE STORMS.

BOYD

PREV DISCUSSION... /ISSUED 320 PM CDT SUN MAY 16 2010/

DISCUSSION...WILL KEEP THE FLOOD WATCH UP AND LET IT EXPIRE AT 7
PM. THE SFC LOW IS LOCATED IN THE VICINITY OF MONTGOMERY...DICKSON
AND HOUSTON COUNTIES AND IS MOVING SLOWLY ENEWD. AREAS NEAR AND EAST
OF THE SFC LOW WILL SEE THE MOST SHOWER AND TSTM ACTIVITY. DIURNAL
TREND SHOULD DIMINISH ACTIVITY SIGNIFICANTLY AFTER 7 PM.

THE PRESSURE PATTERN HAS A 2ND LOW CENTER JUST NORTH OF THE
ARKLATEX...MOVING NEWD. LOCAL WRF MODEL INDICATES THAT THE
CONVECTION ASSOCIATED WITH THIS FEATURE WILL MOVE INTO THE WRN
PORTION OF THE AREA AROUND 11 PM...BUT WILL BE RATHER WEAK AND
ISOLATED. MODEL INDICATES THAT THE HEAVIER PRECIP WILL BE IN SW KY...
SE MO AND SRN IL.

THE 2ND LOW IS EXPECTED TO PASS THROUGH KY TOMORROW AND THEN ON
INTO THE UPPER OHIO VALLEY MON NGT AND TUE. DRIER AIR IS EXPECTED
TO PUSH INTO THE AREA AROUND THE SOUTH SIDE OF THE LOW LATE
TONIGHT AND MON.

NEXT SYSTEM IS STILL OFF THE LEFT COAST AND SHOULD MOVE INTO THE
ROCKIES ON TUE AND INTO THE PLAINS ON WED NGT. MODELS ATTEMPTS TO
SPIT OUT VARIOUS WEAK IMPULSES DOWNSTREAM...BUT DECIDE TO KEEP THE
FORECAST DRY FROM TUE NGT TO WED NGT. THIS SYSTEM PULLS CLOSE
ENOUGH ON THU TO GENERATE A CHANCE OF RAIN ON THU. THE CHANCE OF
RAIN WILL CONTINUE THROUGH SAT UNTIL IT PULLS FAR ENOUGH EAST OF
THE AREA.

&&

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

01

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE NASHVILLE TN
539 AM CDT SUN MAY 16 2010

TNZ005>011-022>034-056>066-075-077>080-093>095-171200-
STEWART-MONTGOMERY-ROBERTSON-SUMNER-MACON-CLAY-PICKETT-BENTON-
HOUSTON-HUMPHREYS-DICKSON-CHEATHAM-DAVIDSON-WILSON-TROUSDALE-
SMITH-JACKSON-PUTNAM-OVERTON-FENTRESS-PERRY-HICKMAN-LEWIS-
WILLIAMSON-MAURY-MARSHALL-RUTHERFORD-CANNON-DE KALB-WHITE-
CUMBERLAND-BEDFORD-COFFEE-WARREN-GRUNDY-VAN BUREN-WAYNE-LAWRENCE-
GILES-
539 AM CDT SUN MAY 16 2010

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF MIDDLE
TENNESSEE.

.DAY ONE...TODAY AND TONIGHT

SHOWERS AND THUNDERSTORMS WILL OCCUR ACROSS THE MID STATE.
SOME HEAVY RAINFALL WILL OCCUR TODAY...ESPECIALLY NORTHWEST OF A
LINE FROM LAWRENCEBURG TO COOKEVILLE. 1 TO 2 INCHES OF RAIN WILL
FALL...WITH LOCALLY 2 TO 4 INCHES FROM HEAVIER DOWNPOURS. A FLASH
FLOOD WATCH HAS BEEN POSTED FOR THE NORTHWEST TWO THIRDS OF THE
MID STATE THROUGH 700 PM.

ALSO...ISOLATED SEVERE STORMS MAY DEVELOP...WITH LARGE HAIL AND
LOCALLY STRONG WINDS. THE RAIN AND THUNDERSTORMS WILL DECREASE IN
COVERAGE AND INTENSITY BY TONIGHT.

.DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY

THE PROBABILITY FOR WIDESPREAD HAZARDOUS WEATHER IS LOW.

.SPOTTER INFORMATION STATEMENT...

REPORTS FROM TRAINED WEATHER SPOTTERS WILL LIKELY BE NEEDED TODAY.

SPOTTER THUNDERSTORM REPORTING CRITERIA...
TORNADO
FUNNEL CLOUD
FLOODING
HAIL >= 1/2 INCH
WINDS > 50 MPH (MEASURED)
STRUCTURAL DAMAGE
TREES OR POWER LINES DOWN

13

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE NASHVILLE TN
856 PM CDT SUN MAY 16 2010

TNZ005-022>024-056-093-170300-
BENTON-HOUSTON-HUMPHREYS-PERRY-STEWART-WAYNE-
856 PM CDT SUN MAY 16 2010

...SIGNIFICANT WEATHER ADVISORY FOR BENTON...HOUSTON...HUMPHREYS...
PERRY...STEWART AND WAYNE COUNTIES...

AT 850 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR WAS TRACKING
STRONG THUNDERSTORMS ALONG A LINE EXTENDING FROM 5 MILES NORTHEAST OF
MURRAY TO 5 MILES SOUTH OF PINEFLAT...OR ALONG A LINE EXTENDING FROM
MURRAY TO 22 MILES SOUTH OF SAVANNAH...MOVING EAST AT 15 MPH. STORMS
ARE SLOW MOVING AND WILL BE CAPABLE OF PRODUCING LOCALLY HEAVY
RAINFALL AS THEY MOVE FIRST INTO BENTON COUNTY AND THEN OTHER
COUNTIES ALONG THE TENNESSEE RIVER IN FAR WESTERN MIDDLE TENNESSEE.

HALF INCH SIZE HAIL...AND WINDS 30 TO 40 MPH ARE SLSO EXPECTED WITH
THE STRONGER STORMS.

BOYD

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE NASHVILLE TN
1039 PM CDT SUN MAY 16 2010

TNZ056>058-093-094-170430-
HICKMAN-LAWRENCE-LEWIS-PERRY-WAYNE-
1039 PM CDT SUN MAY 16 2010

...SIGNIFICANT WEATHER ADVISORY FOR HICKMAN...LAWRENCE...LEWIS...
PERRY AND WAYNE COUNTIES...

AT 1031 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR WAS TRACKING
AN AREA OF SHOWERS AND THUNDERSTORMS THAT WERE PRODUCING HEAVY RAINFALL
ACROSS NORTHWEST WAYNE COUNTY FROM JUST SOUTH OF CLIFTON EAST
THROUGH THE EAGLE CREEK WILDLIFE MANAGEMENT AREA. THIS AREA IS BEING
MONITORED CLOSELY FOR THE POTENTIAL FOR FLASH FLOODING.

BOYD