Severe Thunderstorm Warning 99, NWS Huntsville, AL

Area Forecast Discussion
National Weather Service Huntsville AL
1226 AM CDT Sun May 28 2017

.UPDATE...
For 06Z TAFS.

&&

.NEAR TERM...(Tonight)
Issued at 807 PM CDT Sat May 27 2017

Updated mainly concerning development and evolution of convection to
our north. This convection was basically along the I-40 corridor
from Jackson to south of Nashville to west of Cookeville. Even with
somewhat cooler conditions nearing dusk, very unstable conditions
continued with mixed layer and surface CAPE values in the 2000-3000
J/kg range. Also noticed lower level shear values increasing to our
north as the convection nears.

The HRRR continues a trend of bringing the showers across the area in
the 04-05Z timeframe. But looking at the current radar and storm
movement, think they will be here an hour or so earlier. Strong to
damaging wind gusts and large hail are the main threats. Higher shear
values keeps the possibility of a brief tornado in the picture too.
At this time, think the convection will affect mainly our southern
middle Tennessee and far northeast Alabama counties first, then the
remainder of the area in a NNW-SSE manner in the late evening and
overnight.

Update wise, sped up arrival of likely rain chances for our northern
areas a few hours earlier. Left temperatures and the remaining
parameters as is for now.

.SHORT TERM...(Sunday through Monday)
Issued at 250 PM CDT Sat May 27 2017

If the MCS does move through tonight much of the hires guidance has
it through the area shortly after sunrise Sunday. However, the cold
front will still be lingering off the NW and should spark another
round of convection that will drop S/SE through the area Sunday
afternoon/night. Timing again is very uncertain with the MCS
potentially limiting activity as we may be too worked over. Plus, the
main synoptic forcing with the front will be off to the NE. CAPE and
shear parameters are a bit lower on Sunday and the mid-level dry air
we have over the area today will be gone. So, the potential for
the stronger damaging winds may not be as great. But hail and some
stronger wind gusts are still possible with storms along the front.
The forecast uses more of a blend because of the lingering
uncertainty but if we don't have the MCS come through we could end up
with some severe storms on Sunday with the front.

With the front losing it's main forcing it begins to slow down as it
moves through the area Sunday into Monday. This could shift the
threat from severe to more of a heavy rain and flooding threat on
Monday. Did stick to a blend of guidance for PoPs on Monday and kept
50 to 60 PoPs for much of the area during the day. Thunderstorm
chances begin to decrease as we lose heating Monday evening. With the
increased rain chances and cloud cover temps will be a little
"cooler" on Monday compared to today and Sunday. Hoping to see some
more consistency in the guidance in the next few runs.

.LONG TERM...(Monday night through Friday)
Issued at 250 PM CDT Sat May 27 2017

A broad upper trough remains over N. MN at 00z Monday with a cold
front that will essentially be stalled across N. AL. The upper low
remains wedged between strong high pressure over the N. Atlantic and
the N. Pacific with all the energy well to our north. Locally, a mid
level ridge anchored off the SE coast will allow short waves to ride
along it SW to NE across N. AL. Continued SW flow at the surface
will keep ushering moisture into the area as well. The upper low
finally opens up and meanders eastward on Friday. At the same time,
a weak upper low develops over the midwest and will track eastward.

What this all means is that isolated to scattered thunderstorms will
essentially stay in the forecast for the entire long term period,
Monday night through Saturday night. The highest coverages will be
in the afternoon but isolated showers/storms will probably linger
each evening. Shear is non existent most of the week so would
expected convectively induced showers and maybe a strong storm
possible each afternoon. The dynamics for the weekend look stronger
with greater instability so we'll watch that more in coming
forecasts.

Temperatures for the week will be near normal with highs in the
lower 80s and lows in the lower to mid 60s.

&&

.AVIATION...(For the 06Z TAFS through 06Z Sunday night)
Issued at 1226 AM CDT Sun May 28 2017

Unsettled weather will continue into the overnight, as clusters of
showers and thunderstorms move in a NNW-SSE manner across the region.
Some of the storms, especially towards KMSL could become strong to
severe with strong to damaging wind gusts the main threat during the
overnight. Convection should taper off during Sunday morning as
activity moves south of the region. Given radar trends, have stronger
winds and temporary more reduced CIG/VIS values at KMSL, as the
convection nearing that terminal should miss KHSV. Conditions
otherwise should improve during the day Sunday as a more stable
atmosphere returns. Shower chances however will continue, but did not
include them in the latter hours of the TAF due to uncertainty.

&&

.HUN WATCHES/WARNINGS/ADVISORIES...
AL...NONE.
TN...NONE.
&&

NEAR TERM...RSB
SHORT TERM...Stumpf
LONG TERM...LN
AVIATION...RSB

For more information please visit our website
at weather.gov/huntsville.

Hazardous Weather Outlook
National Weather Service Huntsville AL
637 PM CDT Sat May 27 2017

ALZ001>010-016-TNZ076-096-097-281000-
Lauderdale-Colbert-Franklin AL-Lawrence-Limestone-Madison-Morgan-
Marshall-Jackson-De Kalb-Cullman-Moore-Lincoln-Franklin TN-
637 PM CDT Sat May 27 2017

This Hazardous Weather Outlook is for north Alabama and portions of
southern middle Tennessee.

.DAY ONE...Tonight...

More numerous thunderstorms will impact the region late this evening
and overnight. Some of these storms will be strong to severe, with
the main threats damaging wind gusts over 60 mph and large hail. A few
tornadoes cannot be ruled out within the strongest storms.

.DAYS TWO THROUGH SEVEN...Sunday through Friday...

Thunderstorms may still be ongoing across portions of the outlook
area Sunday morning, although the coverage should diminish during the
afternoon. Regardless of coverage, conditions may be favorable for
the redevelopment of strong to severe thunderstorms Sunday afternoon.

A slow moving cold front will bring more widespread storms Sunday
night and Monday. Although a few strong to marginally severe storms
will be possible, the greatest threat will come from locally heavy
rainfall.

The cold front is expected to stall near or just south of the
region, with generally low to moderate chances for storms continuing
through Friday.

.SPOTTER CALL TO ACTION STATEMENT...

Activation of storm spotters and emergency management personnel is
likely tonight.

BCC

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE HUNTSVILLE AL
145 AM CDT SUN MAY 28 2017

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0122 AM     TSTM WND GST     3 NNW PHIL CAMPBELL     34.39N 87.73W
05/28/2017  E60 MPH          FRANKLIN           AL   TRAINED SPOTTER

            SPOTTER ESTIMATED WINDS OF AT LEAST 60 MPH,
            POSSIBLY HIGHER, IN SPRUCE PINE. TIME
            ADJUSTED BASED ON RADAR.

&&

BCC

Special Weather Statement
National Weather Service Huntsville AL
145 AM CDT SUN MAY 28 2017

ALZ006-008-009-280715-
Marshall AL-Madison AL-Jackson AL-
145 AM CDT SUN MAY 28 2017

...SIGNIFICANT WEATHER ADVISORY FOR SOUTHWESTERN JACKSON...NORTHERN
MARSHALL AND SOUTHEASTERN MADISON COUNTIES UNTIL 215 AM CDT...

At 145 AM CDT, Doppler radar was tracking a strong thunderstorm over
Owens Cross Roads, or 15 miles northwest of Guntersville, moving east
at 30 mph.

Wind gusts up to 50 mph will be possible with this storm.

Locations impacted include...
Scottsboro, Owens Cross Roads, Grant, Section, Woodville, Langston,
Paint Rock, Lim Rock, Hebron and Larkinsville.

This storm may intensify, so be certain to monitor local radio
stations and available television stations for additional information
and possible warnings from the National Weather Service.

LAT...LON 3448 8602 3447 8603 3447 8607 3445 8648
      3463 8651 3474 8604 3449 8598
TIME...MOT...LOC 0645Z 260DEG 28KT 3456 8641

RSB

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE HUNTSVILLE AL
146 AM CDT SUN MAY 28 2017

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0134 AM     HAIL             12 W MOULTON            34.46N 87.48W
05/28/2017  E1.00 INCH       LAWRENCE           AL   BROADCAST MEDIA

            QUARTER SIZE HAIL REPORTED IN MOUNT HOPE.

&&

BCC

Special Weather Statement
National Weather Service Huntsville AL
149 AM CDT SUN MAY 28 2017

ALZ007-008-280715-
Marshall AL-Morgan AL-
149 AM CDT SUN MAY 28 2017

...SIGNIFICANT WEATHER ADVISORY FOR WEST CENTRAL MARSHALL AND
SOUTHEASTERN MORGAN COUNTIES UNTIL 215 AM CDT...

At 149 AM CDT, Doppler radar was tracking a strong thunderstorm 8
miles southwest of Morgan City, or 10 miles northwest of Arab, moving
east at 30 mph.

Wind gusts up to 50 mph will be possible with this storm.

Locations impacted include...
Arab, Morgan City, Eva, Union Grove, Hulaco, Eddy, Ryan Crossroads
and Florette.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Strong gusty winds will be capable of knocking down small tree limbs
along with other small unsecured items. Seek safe shelter until this
storm has passed.

&&

LAT...LON 3429 8648 3431 8674 3446 8678 3451 8654
      3449 8652 3448 8648 3445 8648 3446 8638
      3429 8635
TIME...MOT...LOC 0649Z 260DEG 27KT 3439 8667

RSB

Special Weather Statement
National Weather Service Huntsville AL
153 AM CDT SUN MAY 28 2017

ALZ005-006-008-009-280730-
Marshall AL-Madison AL-Limestone AL-Jackson AL-
153 AM CDT SUN MAY 28 2017

...SIGNIFICANT WEATHER ADVISORY FOR WEST CENTRAL JACKSON...
NORTHWESTERN MARSHALL...MADISON AND EASTERN LIMESTONE COUNTIES UNTIL
230 AM CDT...

At 152 AM CDT, Doppler radar was tracking strong thunderstorms along
a line extending from near Ardmore to near Huntsville International
Airport. Movement was southeast at 40 mph.

Pea size hail and wind gusts of 45 to 50 mph will be possible with
these storms.

Locations impacted include...
Huntsville, Madison, Guntersville, Moores Mill, Meridianville,
Redstone Arsenal, Hazel Green, Owens Cross Roads, Gurley and
Woodville.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Strong gusty winds will be capable of knocking down small tree limbs
along with other small unsecured items. Seek safe shelter until this
line of storms has passed.

&&

LAT...LON 3489 8624 3440 8629 3451 8656 3456 8655
      3458 8658 3458 8661 3455 8664 3455 8666
      3459 8669 3457 8673 3465 8693 3499 8681
TIME...MOT...LOC 0652Z 298DEG 33KT 3499 8676 3463 8687

70/DD

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE HUNTSVILLE AL
204 AM CDT SUN MAY 28 2017

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0133 AM     TSTM WND DMG     1 SW MOULTON            34.47N 87.29W
05/28/2017                   LAWRENCE           AL   EMERGENCY MNGR

            TREE DOWN NEAR MARKET STREET AND BYLER ROAD.

&&