Severe Thunderstorm Warning 49, NWS Nashville, TN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NASHVILLE TN
406 AM CDT SAT MAY 1 2010

.DISCUSSION...
LATEST ANALYSIS SHOWING CLOSED SFC LOW NORTHERN PLAINS VCNTY WITH
FRONTAL BOUNDARY STRETCHING DOWN JUST WEST OF THE MS RIVER. UL LOW
IN MAIN AREA BUT TROUGH AXIS STILL WELL AWAY...DOWN INTO THE DESERT
SOUTHWEST. GOOD LL JET SHOWING UP JUST AHEAD OF BOUNDARY WHICH IS
HELPING TO FUEL LINE OF STRONG/SEVERE THUNDERSTORMS IN THE MID-
STATE.

CURRENT BOUNDARY WASHES OUT LATER THIS MORNING WHILE ANOTHER FORMS
TOWARD LIT IN WAVE MOVING UP FROM TX LATE TODAY. LL JET WILL WEAKEN
SOME THIS MORNING BUT WILL MOVE OVER THE AREA...ALLOWING LINE OF
STORMS TO CONTINUE MOVING EAST AS AIRMASS ALREADY UNSTABLE AND WITH
GOOD MOISTURE ADVECTION OCCURRING. WIND STRUCTURE MAY ALLOW FOR
THE DEVELOPMENT OF SEVERE THUNDERSTORMS ALONG WITH ISO TORNADOES.
ADDITIONALLY...INCREASING UVV AS WELL AS INCREASING MOISTURE
SETTING UP TO PRODUCE HEAVY RAINFALL WHICH MAY LEAD TO LOCALIZED
FLOODING.

DEVELOPING SFC/LL LOW MOVES UP INTO THE GREAT LAKES TONIGHT...THEN
INTO CANADA SUNDAY AS ANOTHER WEAK WAVE FORMS TO THE SOUTHWEST.
UL TROUGH REMAINS WELL WEST LEAVING ML/UL FLOW MORE PARALLEL AND
PRESENCE OF WAVE VERY MUCH SLOWS SOUTHERN FLANK OF BOUNDARY. THIS
WILL LEAVE THE CWA IN IMMEDIATE VCNTY OF DEEP MOISTURE AXIS AS
WELL AS IN FAVORABLE UVV/INSTABILITY REGION...THUS KEEPING THREAT
OF MORE SEVERE STORMS AND/OR LOCALIZED FLOODING RUNNING THROUGH EARLY
MONDAY...AT WHICH TIME SFC/LL BOUNDARY MOVES THROUGH. AT THIS
POINT...WILL KEEP FLOOD WATCH AS IS. CUMBERLAND PLATEAU LIKELY TO
SEE BETTER FLOODING THREAT SUNDAY THROUGH EARLY MONDAY. ANTICIPATE
FLOOD WATCH WILL BE ADJUSTED AT LATER TIME.

LINGERING SHOWERS/STORMS WILL CONTINUE INTO MONDAY AFTERNOON AS
SFC/LL BOUNDARY MOVES EVER SO SLOWLY EAST...WITH ISO SHOWERS ON
TAP MONDAY NIGHT/TUESDAY AS ML/UL FINALLY SWING EAST.

MID-WEEK SEEMINGLY DRY BUT ANOTHER FRONTAL BOUNDARY SET TO PASS
AND BRING PCPN BACK TO THE MID-STATE ON FRIDAY.

&&

.PRELIMINARY POINT TEMPS/POPS...
NASHVILLE      81  71  76  57 /  80  80  90  80
CLARKSVILLE    78  69  73  55 /  80  80  80  60
CROSSVILLE     77  68  78  61 /  70  60  80  80
COLUMBIA       83  71  78  59 /  80  80  90  80
LAWRENCEBURG   81  71  80  59 /  80  80  90  80
WAVERLY        80  71  75  56 /  80  80  80  60

&&

.OHX WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH FROM 7 AM CDT THIS MORNING THROUGH MONDAY
MORNING FOR TNZ005>010-022>031-056>064-075-077-093>095.

&&

07

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE NASHVILLE TN
411 PM CDT FRI APR 30 2010

TNZ005>010-022>031-056>064-075-077-093>095-012115-
STEWART-MONTGOMERY-ROBERTSON-SUMNER-MACON-CLAY-BENTON-HOUSTON-
HUMPHREYS-DICKSON-CHEATHAM-DAVIDSON-WILSON-TROUSDALE-SMITH-
JACKSON-PERRY-HICKMAN-LEWIS-WILLIAMSON-MAURY-MARSHALL-RUTHERFORD-
CANNON-DE KALB-BEDFORD-COFFEE-WAYNE-LAWRENCE-GILES-
411 PM CDT FRI APR 30 2010

...FLASH FLOOD WATCH IN EFFECT FROM SATURDAY MORNING THROUGH
MONDAY MORNING...

THIS HAZARDOUS WEATHER OUTLOOK IS FOR MIDDLE TENNESSEE.

.DAY ONE...THIS AFTERNOON AND TONIGHT

SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECT TONIGHT...MAINLY IN
THE WESTERN AREAS OF THE MIDSTATE. ISOLATED SEVERE STORMS ARE
POSSIBLE IN THE EXTREME NORTHWESTERN COUNTIES LATE TONIGHT.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY

NUMEROUS SHOWERS AND THUNDERSTORMS ARE EXPECTED FOR SATURDAY THROUGH
SUNDAY. ISOLATED SEVERE THUNDERSTORMS ARE POSSIBLE DURING THIS PERIOD.
GREATEST THREAT IS DAMAGING WINDS AND HAIL. AT THE SAME TIME...
WIDESPREAD RAINFALL...HEAVY AT TIMES...MAY PRODUCE FLASH FLOODING
OVER THE MIDSTATE THROUGH SUNDAY NIGHT.

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

.SPOTTER INFORMATION STATEMENT...

REPORTS FROM TRAINED WEATHER SPOTTERS MAY BE NEEDED.

TNZ011-032>034-065-066-078>080-012115-
PICKETT-PUTNAM-OVERTON-FENTRESS-WHITE-CUMBERLAND-WARREN-GRUNDY-
VAN BUREN-
411 PM CDT FRI APR 30 2010

THIS HAZARDOUS WEATHER OUTLOOK IS FOR MIDDLE TENNESSEE.

.DAY ONE...THIS AFTERNOON AND TONIGHT

NO SIGNIFICANT WEATHER OVER THE CUMBERLAND PLATEAU TONIGHT. NO
HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY

NUMEROUS SHOWERS AND THUNDERSTORMS ARE EXPECTED FOR SATURDAY
THROUGH SUNDAY. ISOLATED SEVERE THUNDERSTORMS ARE POSSIBLE DURING
THIS PERIOD. GREATEST THREAT IS DAMAGING WINDS AND HAIL. AT THE
SAME TIME WE EXPECT WIDESPREAD RAINFALL...POSSIBLY HEAVY AT
TIMES.

.SPOTTER INFORMATION STATEMENT...

REPORTS FROM TRAINED WEATHER SPOTTERS MAY 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

JLM

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE NASHVILLE TN
217 AM CDT SAT MAY 1 2010

TNZ005-022>024-010800-
BENTON-HOUSTON-HUMPHREYS-STEWART-
217 AM CDT SAT MAY 1 2010

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

AT 209 AM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR WAS TRACKING A
LINE OF STRONG THUNDERSTORMS 29 MILES WEST OF BUENA VISTA...OR 34
MILES SOUTHWEST OF PARIS...MOVING EAST AT 30 MPH. HIGH WINDS HAVE
BEEN REPORTED ALONG THIS LINE ALONG WITH LARGE HAIL. RESIDENTS IN
BENTON...HOUSTON...HUMPREYS AND STEWART COUNTIES SHOULD REMAIN ALERT
AS WARNINGS MAY BE NEEDED SHORTLY FOR YOUR AREA.

BOYD