Special Weather Statement, NWS Nashville, TN

Area Forecast Discussion
National Weather Service Nashville TN
206 PM CDT MON JUL 4 2016

.DISCUSSION...

Scattered showers and thunderstorms are ongoing around Middle
Tennessee at forecast time.  These storms have shown some
indications of strengthening over the last hour or two, which has
sparked the need for a Severe Thunderstorm Watch across our
northern counties. Current analysis shows a quasi-stationary
boundary stretching across the lower Ohio Valley swwd into MO and
a surface low near the MO/IL state line. This surface low has
helped to strengthen the bulk shear values across KY, with some
25-30 kt values dipping into northern Middle Tennessee. It's this
shear, coupled with CAPE values in the 1500-2000 J/KG range that
are helping to organize this afternoon's activity. However, that's
not the end of the story. An upper level trough currently over the
central plains is expected to enter the region this evening. As it
does so, additional thunderstorm development will ensue. The
problem is, increased shear values are expected to make their way
into the mid-state at the same time. While we will begin to lose
the heating of the day by 7 pm, there should still be enough
instability remaining across the region to interact with the
incoming shear to organize more activity this evening.
Expectations are for storms to develop upstream late this
afternoon and move into the mid-state this evening. Unfortunately,
this is likely to put a damper on evening Independence Day
activities. Have bumped evening PoPs into the categorical range
through midnight. Not sure whether or not another Severe
Thunderstorm Watch will become necessary, however, if these storms
can organize, we will see a straight line wind threat develop and
an additional watch may need to be issued. On top of the severe
weather potential, PWATs of around 2 inches are plaguing the area.
This means rainfall that does occur is going to be very efficient.
Counties along the KY state line saw quite a bit of rain last
night -- some reports of 2 to 3.5 inches have been seen. Because
of this and the potential for another 1 to 2 inches in a short
period of time this evening, we will continue the Flash Flood
Watch for these counties through Tuesday morning.

This second wave should come to an end after midnight, but (isn't
there always one of those?) models are indicating a third upper
level impulse could bring more showers and thunderstorms into the
state by early Tuesday morning.  The good news is that without a
surface low to provide shear for organization, these should be
general thunderstorms at best.  Precipitation should slowly wane
throughout the day on Tuesday and we should be dry Tuesday night.

The rest of the forecast is going to be characterized by very summer-
like conditions.  Afternoon highs in the upper 80s and low 90s and a
chance of afternoon showers and thunderstorms, lasting into the
evening hours, each day. Each day will present an opportunity for
strong gusty winds due to afternoon instability values being high.
If there's one day I would say PoPs would be a little lower (just
a slight chance of afternoon precip), I would say it's Friday as
some upper level ridging works into the region. However, that will
be short lived as another boundary (one similar to today) will
drop into the TN Valley Saturday.

&&

.AVIATION...
18Z TAF DISCUSSION.

With temps approaching convective levels, shower and tstm activity
will increase with time. Look for coverage to increase further
still as pva swings across the area tonight. Some gusty winds will
be prevalent in subsidence zones and also with the convection that
occurs later. 00z to 06z should be the most active period for the
strongest storms. Cigs will lower to mvfr levels and ifr at times
later tonight.

&&

.PRELIMINARY POINT TEMPS/POPS...
Nashville      74  88  74  92  76 /  80  50  30  50  20
Clarksville    73  87  73  91  75 /  80  30  20  40  20
Crossville     69  81  68  85  68 /  70  60  40  50  40
Columbia       73  87  73  91  74 /  80  50  30  50  20
Lawrenceburg   72  86  72  90  73 /  70  60  30  50  20
Waverly        72  87  74  91  75 /  80  30  20  40  20

&&

.OHX WATCHES/WARNINGS/ADVISORIES...
Flash Flood Watch through Tuesday morning FOR Clay-Macon-
Montgomery-Pickett-Robertson-Stewart-Sumner.

&&

DISCUSSION......Unger
AVIATION........21

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE NASHVILLE TN
504 AM CDT MON JUL 4 2016

TNZ005>011-051030-
STEWART-MONTGOMERY-ROBERTSON-SUMNER-MACON-CLAY-PICKETT-
504 AM CDT MON JUL 4 2016

...FLASH FLOOD WATCH FOR EXTREME NORTHERN MIDDLE TENNESSEE THROUGH
7 AM CDT TUESDAY...

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF MIDDLE
TENNESSEE.

.DAY ONE...TODAY AND TONIGHT

THUNDERSTORMS BECOMING WIDESPREAD ACROSS THE EXTREME NORTH...
ESPECIALLY THIS AFTERNOON AND EVENING. A FEW STORMS MAY BE SEVERE
WITH DAMAGING WINDS AND LARGE HAIL. IN ADDITION...HEAVY DOWNPOURS
MAY PRODUCE FLASH FLOODING OF LOW LYING AND POORLY DRAINED AREAS.
A FLASH FLOOD WATCH IS POSTED FOR ALL OF EXTREME NORTHERN MIDDLE
TENNESSEE UNTIL 7 AM TUESDAY... INCLUDING ALL COUNTIES THAT BORDER
KENTUCKY.

.DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY

THE PROBABILITY OF WIDESPREAD HAZARDOUS WEATHER IS LOW.

.SPOTTER INFORMATION STATEMENT...SPOTTERS ARE ENCOURAGED TO PASS
ALONG ANY REPORTS OF FLASH FLOODING, WIND DAMAGE OR LARGE HAIL TO
THE NATIONAL WEATHER SERVICE.

TNZ023>034-056>066-075-077>080-093>095-051030-
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-
504 AM CDT MON JUL 4 2016

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF MIDDLE
TENNESSEE.

.DAY ONE...TODAY AND TONIGHT

THUNDERSTORMS DEVELOPING AND INCREASING IN COVERAGE...ESPECIALLY
THIS AFTERNOON AND EVENING. A FEW STORMS MAY BE SEVERE WITH
DAMAGING WINDS AND LARGE HAIL. IN ADDITION...HEAVY DOWNPOURS MAY
PRODUCE BRIEF PONDING OF WATER IN LOW LYING AND POORLY DRAINED
AREAS.

.DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY

THE PROBABILITY OF WIDESPREAD HAZARDOUS WEATHER IS LOW.

.SPOTTER INFORMATION STATEMENT...SPOTTERS ARE ENCOURAGED TO PASS
ALONG ANY REPORTS OF FLASH FLOODING, WIND DAMAGE OR LARGE HAIL TO
THE NATIONAL WEATHER SERVICE.

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SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE NASHVILLE TN
220 PM CDT MON JUL 4 2016

TNZ008-027-028-041945-
DAVIDSON TN-SUMNER TN-WILSON TN-
220 PM CDT MON JUL 4 2016

...SIGNIFICANT WEATHER ADVISORY FOR SOUTHEASTERN DAVIDSON...SOUTH
CENTRAL SUMNER AND NORTHWESTERN WILSON COUNTIES UNTIL 245 PM CDT...

AT 219 PM CDT...DOPPLER RADAR WAS TRACKING A STRONG THUNDERSTORM NEAR
NASHVILLE...MOVING NORTHEAST AT 40 MPH.

WINDS IN EXCESS OF 40 MPH WILL BE POSSIBLE WITH THIS STORM.

LOCATIONS IMPACTED INCLUDE...
GALLATIN...LEBANON...HENDERSONVILLE...MOUNT JULIET...LAKEWOOD...
HERMITAGE...OLD HICKORY...BELINDA CITY...RURAL HILL...
ANTIOCH AND PERCY PRIEST LAKE.

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 800 PM CDT FOR
MIDDLE TENNESSEE.

LAT...LON 3639 8644 3618 8627 3609 8650 3610 8652
      3609 8652 3608 8654 3609 8655 3608 8655
      3603 8667 3621 8680
TIME...MOT...LOC 1919Z 240DEG 49KT 3615 8671

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