Flash Flood Warning 18, NWS Nashville, TN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NASHVILLE TN
330 AM CDT SUN MAY 16 2010

.DISCUSSION...FLOOD POTENTIAL IS THE MAIN CONCERN TODAY. OUR
CURRENT FLASH FLOOD WATCH APPEARS ON TRACK...COVERING LOCATIONS
THAT HAVE HAD THE MOST SIGNIFICANT RAINFALL OVER THE PAST COUPLE
OF DAYS...AND ARE EXPECTED TO HAVE THE MOST TODAY. EXPECTED
BASIN AVERAGE RAINFALL FROM NOW UNTIL 7 PM CDT IS 1-2 INCHES
ACROSS THE WATCH AREA. LOCALLY GREATER AMOUNTS (3 TO 4 INCHES) WILL
CERTAINLY OCCUR UNDER HEAVY THUNDERSTORMS. ISOLATED SEVERE WEATHER
IS POSSIBLE TODAY...INCLUDING HAIL AND BRIEF GUSTY WINDS...BUT
THREAT APPEARS A LITTLE LOWER THAN PREVIOUS COUPLE OF DAYS.

ALL OF THIS MESS IS ASSOCIATED WITH A STALLED BOUNDARY OVER THE
REGION. THE BOUNDARY APPEARS TO BE LOCATED NEAR THE TN/KY
BORDER...AND EXTENDS BACK TO SURFACE LOW PRESSURE OVER THE MID
SOUTH. RAIN HAD DIMINISHED LAST EVENING...BUT WE HAVE SEEN
SIGNIFICANT REDEVELOPMENT OVER THE PAST COUPLE OF HOURS OVER OUR
WESTERN COUNTIES...BACK INTO WEST TN AND NORTH MS. THIS NEW
DEVELOPMENT APPEARS TO BE LINKED TO AN MCV AND THE SURFACE LOW
PRESSURE AREA...WHICH WILL MOVE FROM SOUTHWEST TO NORTHEAST ACROSS
MID TN TODAY. WE WILL GO WITH A 100 PERCENT POP ACROSS THE AREA
WITH HEAVY RAINFALL AT TIMES...ESPECIALLY MID MORNING TO MID
AFTERNOON WHEN THUNDERSTORMS WILL BE MOST LIKELY.

RAIN COVERAGE AND INTENSITY WILL DIMINISH BY THIS EVENING AS THE
DEEPEST MOISTURE AND STRONGEST IMPULSES PULLS EAST...BUT THERE
WILL CONTINUE TO BE SCATTERED SHOWERS AND A FEW THUNDERSTORMS
UNTIL THE MAIN TROUGH AND SURFACE BOUNDARY MOVE EAST OF THE
AREA MONDAY PM.

DRIER AND A LITTLE COOLER CONDITIONS ARE EXPECTED TUESDAY AND
WEDNESDAY. THE EXTENDED FORECAST HAS MORE UNCERTAINTY WITH
POSSIBLE EFFECTS FROM NEXT SYSTEM THAT WILL MOVE OUT OF THE
PLAINS. LATEST GFS SHOWS POPS COMING IN SOONER THAN PREVIOUS
FORECAST. WE WILL TREND THAT WAY BY ADDING SMALL POPS TO
THURSDAY...WHILE KEEPING FOCUS ON FRIDAY FOR THE HIGHEST POPS
WITH THE NEXT SYSTEM.

&&

.PRELIMINARY POINT TEMPS/POPS...
NASHVILLE      76  63  78  57 / 100  60  40  10
CLARKSVILLE    77  60  76  54 / 100  60  50  10
CROSSVILLE     75  62  75  54 / 100  90  50  20
COLUMBIA       78  64  80  58 / 100  60  40  10
LAWRENCEBURG   79  64  80  58 / 100  60  30  10
WAVERLY        78  62  78  56 / 100  60  40  10

&&

.OHX WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH THROUGH THIS EVENING FOR TNZ005>011-022>034-
056>060-062-093-094.

&&

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

TNZ061-063>066-075-077>080-095-170630-
MARSHALL-CANNON-DE KALB-WHITE-CUMBERLAND-BEDFORD-COFFEE-WARREN-
GRUNDY-VAN BUREN-GILES-
129 AM CDT SUN MAY 16 2010

THIS HAZARDOUS WEATHER OUTLOOK IS FOR MIDDLE TENNESSEE.

.DAY ONE...REST OF THE NIGHT

EARLY IN THE NIGHT...A STATIONARY FRONT EXTENDED FROM NEAR
MEMPHIS TO NEAR NASHVILLE AND THEN NORTHEASTWARD INTO SOUTHERN
KENTUCKY. A CHANCE FOR SHOWERS AND THUNDERSTORMS WILL CONTINUE
IN VICINITY OF THIS FRONT...SOME WITH LOCALLY HEAVY RAINFALL.

.DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY

SHOWERS AND THUNDERSTORMS ARE EXPECTED SUNDAY...SOME WITH HEAVY
DOWNPOURS WHICH COULD...ONCE AGAIN...LEAD TO LOCALIZED FLOOD
PROBLEMS. A FEW STORMS COULD BECOME SEVERE. THE SHOWERS AND
THUNDERSTORMS WILL DIMINISH FROM THE WEST SUNDAY NIGHT...WITH
SCATTERED SHOWERS AND THUNDERSTORMS POSSIBLE MONDAY.

.SPOTTER INFORMATION STATEMENT...

REPORTS FROM TRAINED WEATHER SPOTTERS WILL LIKELY BE NEEDED.

TNZ005>011-022>034-056>060-062-093-094-170630-
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-RUTHERFORD-WAYNE-LAWRENCE-
129 AM CDT SUN MAY 16 2010

...FLASH FLOOD WATCH IN EFFECT THROUGH SUNDAY EVENING...

THIS HAZARDOUS WEATHER OUTLOOK IS FOR MIDDLE TENNESSEE.

.DAY ONE...REST OF THE NIGHT

A STATIONARY FRONT EXTENDED FROM NEAR MEMPHIS TO NEAR NASHVILLE AND
THEN NORTHEASTWARD INTO SOUTHERN KENTUCKY. A LOW PRESSURE AREA
WILL MOVE NORTHEASTWARD ALONG THE FRONT TONIGHT AND PUSH NUMEROUS
SHOWERS AND SCATTERED THUNDERSTORMS INTO WESTERN PARTS OF THE MID
STATE AND THE INTERSTATE 65 CORRIDOR. LOCALLY HEAVY RAINFALL WILL
OCCUR...WHICH MAY PRODUCE LOCALIZED FLOODING.

MORE INFORMATION IS AVAILABLE ON THE INTERNET AT WEATHER.GOV OR
BY LISTENING TO NOAA WEATHER RADIO.

.DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY

SHOWERS AND THUNDERSTORMS ARE EXPECTED SUNDAY...SOME WITH HEAVY
DOWNPOURS WHICH COULD...ONCE AGAIN...LEAD TO LOCALIZED FLOOD
PROBLEMS. A FEW STORMS COULD BECOME SEVERE. THE SHOWERS AND
THUNDERSTORMS WILL DIMINISH FROM THE WEST SUNDAY NIGHT...WITH
SCATTERED SHOWERS AND THUNDERSTORMS POSSIBLE MONDAY.

.SPOTTER INFORMATION STATEMENT...

REPORTS FROM TRAINED WEATHER SPOTTERS WILL LIKELY BE NEEDED.

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

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