Special Weather Statement, NWS Huntsville, AL

Area Forecast Discussion
National Weather Service Huntsville AL
316 PM CDT Wed Oct 6 2021

.NEAR TERM...(Tonight)
Issued at 316 PM CDT Wed Oct 6 2021

The threat for flash flooding and strong to severe storms will
continue into the evening hours, as a stacked low pressure system
continues shifting north northwest, keeping a moist airmass over
southern middle Tennessee and north central and northeast AL. Breaks
in cloud cover have aided in destabilization early this afternoon,
with current MLCAPE values between 1500-2000 J/kg. This, combined
with increasing bulk shear between 30-35kts could result in a few
strong to severe storms later this afternoon and evening. Damaging
winds and a few tornadoes will be the primary hazards, but quarter-
sized hail will also be possible. Believe the severe threat will
gradually taper off shortly after sunset with the loss of daytime
heating, and flash flooding will become the primary concern over NE
AL. This will become especially hazardous overnight as flooding on
roadways and low lying areas will become more difficult to see.

With drier air wrapping around the southeast side of the low, believe
northwest AL will dry out overnight and the majority of showers and
storms will be confined to areas east of I-65. If clearing occurs
over northwest AL, some patchy fog could develop during the early
morning hours, but did not feel confident enough to include in the
afternoon update.

.SHORT TERM...(Thursday through Friday)
Issued at 316 PM CDT Wed Oct 6 2021

As the upper low begins to shift northeast toward the Great Lakes
region, drier air will continue to filter into the area from the
southwest. This should keep shower and storm activity confined to
areas east of I-65. Coverage remains a bit more uncertain tomorrow,
as guidance has trended a little more aggressive with the drier air
intrusion. That being said, any rainfall over northeast AL could fall
as runoff depending on the rainfall amounts received later today and
tonight. For now, additional QPF not expected to exceed 0.5" on
Thursday. High temps will climb into the upper 70s to perhaps lower
80s Thursday afternoon, then into the lower 80s on Friday. Did
maintain a mention of isolated thunderstorms Friday afternoon along
the AL/GA state line, but believe the area will largely stay dry.
Overnight lows will be in the lower 60s, and some patchy fog
development will be possible during the early morning hours.

.LONG TERM...(Friday night through Tuesday)
Issued at 316 PM CDT Wed Oct 6 2021

A beautiful but warm fall weekend is on tap for the Tennessee Valley,
as northwest flow settles in aloft and an upper ridge begins
building east over the ArkLaTex region. This will keep dry and warm
conditions in place over the weekend, with highs in the low to mid
80s. Overnight lows will be in the low to mid 60s through the
extended period. A pacific front will dive over the central and
southern Plains early next week, but confidence is decreasing on that
front making it into the Tennessee Valley before being held up by a
building ridge over the central Gulf. For that reason, only mentioned
slight chance PoPs Tuesday and even that might be overdone. High
temps will remain slightly above seasonal norms through the extended
forecast period.

&&

.AVIATION...(For the 18Z TAFS through 18Z Thursday afternoon)
Issued at 1238 PM CDT Wed Oct 6 2021

Showers and thunderstorms will continue to impact the KHSV TAF site
through the evening hours, as multiple rounds of heavy rain are
expected. Coverage should remain more isolated at KMSL, but brief
periods of SHRA/TSRA are possible. Reductions to MVFR/IFR cigs/vsbys
will be possible within these storms, and reductions to LIFR cigs and
could occur if low stratus occurs overnight. If clearing occurs over
NW AL overnight, some fog formation will be possible. Confidence was
not high enough to include fog in this TAF issuance.

&&

.HUN WATCHES/WARNINGS/ADVISORIES...
AL...Flash Flood Watch until 1 AM CDT Thursday for ALZ001>010-016.

TN...Flash Flood Watch until 1 AM CDT Thursday for TNZ076-096-097.

&&

NEAR TERM...25
SHORT TERM...25
LONG TERM...25
AVIATION...25

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

Hazardous Weather Outlook
National Weather Service Huntsville AL
257 PM CDT Wed Oct 6 2021

ALZ001>010-016-TNZ076-096-097-071100-
Lauderdale-Colbert-Franklin AL-Lawrence-Limestone-Madison-Morgan-
Marshall-Jackson-DeKalb-Cullman-Moore-Lincoln-Franklin TN-
257 PM CDT Wed Oct 6 2021

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

.DAY ONE...Tonight...

Heavy rain and thunderstorms remain possible well into the evening
hours, as an upper disturbance remains in place west of the area. A
few of these storms may be strong to severe, with the potential for
damaging wind gusts, small hail and brief tornadoes, mainly for
locations along and east of the Interstate 65 corridor. The threat
for localized flash flooding also remains in place and a Flash Flood
Watch remains in effect through 1 AM CDT tonight.

.DAYS TWO THROUGH SEVEN...Thursday through Tuesday...

Lingering thunderstorms remain possible for areas along and east of
Interstate 65 Thursday before the thunderstorm threat diminishes
Thursday evening.

.SPOTTER CALL TO ACTION STATEMENT...

Activation of storm spotters and emergency management personnel is
possible late this afternoon and this evening.

Special Weather Statement
National Weather Service Huntsville AL
211 PM CDT Wed Oct 6 2021

ALZ016-062000-
Cullman AL-
211 PM CDT Wed Oct 6 2021

...A strong thunderstorm will impact portions of western Cullman
County through 300 PM CDT...

At 211 PM CDT, Doppler radar was tracking a strong thunderstorm near
Dodge City, or 13 miles southeast of Arley, moving northeast at 30
mph.

HAZARD...Winds in excess of 40 mph and nickel size hail.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects. Minor damage to outdoor objects is
         possible.

Locations impacted include...
Cullman, Hanceville, Good Hope, Dodge City, Baldwin, Vinemont,
Baileyton, West Point, Colony and Phelan.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

If on or near Smith Lake, get out of the water and move indoors or
inside a vehicle. Remember, lightning can strike out to 10 miles
from the parent thunderstorm. If you can hear thunder, you are close
enough to be struck by lightning. Move to safe shelter now! Do not
be caught on the water in a thunderstorm.

&&

LAT...LON 3389 8694 3398 8709 3430 8704 3425 8660
TIME...MOT...LOC 1911Z 208DEG 27KT 3401 8699

MAX HAIL SIZE...0.88 IN
MAX WIND GUST...40 MPH

30

Special Weather Statement
National Weather Service Huntsville AL
407 PM CDT Wed Oct 6 2021

ALZ006-008-009-062145-
Marshall AL-Madison AL-Jackson AL-
407 PM CDT Wed Oct 6 2021

...A strong thunderstorm will impact portions of southwestern
Jackson, northeastern Marshall and southeastern Madison Counties
through 445 PM CDT...

At 407 PM CDT, Doppler radar was tracking a strong thunderstorm 7
miles east of Grant, or 9 miles southwest of Scottsboro, moving north
at 35 mph.

HAZARD...Winds in excess of 40 mph and penny size hail.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects. Minor damage to outdoor objects is
         possible.

Locations impacted include...
Scottsboro, Grant, Skyline, Gurley, Section, Woodville, Pleasant
Groves, Langston, Paint Rock and Lim Rock.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

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.

A Tornado Watch remains in effect until 1000 PM CDT for north central
and northeastern Alabama.

&&

LAT...LON 3453 8594 3447 8618 3450 8637 3471 8639
      3482 8602
TIME...MOT...LOC 2107Z 165DEG 30KT 3457 8614

MAX HAIL SIZE...0.75 IN
MAX WIND GUST...40 MPH

30

Special Weather Statement
National Weather Service Huntsville AL
435 PM CDT Wed Oct 6 2021

ALZ016-062200-
Cullman AL-
435 PM CDT Wed Oct 6 2021

...A strong thunderstorm will impact portions of western Cullman
County through 500 PM CDT...

At 434 PM CDT, Doppler radar was tracking a strong thunderstorm near
Smith Dam, or 12 miles north of Sumiton, moving north at 35 mph.

HAZARD...Wind gusts up to 50 mph and nickel size hail.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects. Minor damage to outdoor objects is
         possible.

Locations impacted include...
Dodge City, West Point, Colony, Wilburn, Logan, Bremen, Arkadelphia,
Crane Hill, Jones Chapel and Smith Lake.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Frequent cloud to ground lightning is occurring with this storm.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.

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.

A Tornado Watch remains in effect until 1000 PM CDT for north central
Alabama.

&&

LAT...LON 3389 8701 3390 8710 3391 8708 3392 8708
      3394 8711 3396 8711 3397 8714 3399 8715
      3399 8711 3424 8711 3426 8697 3392 8689
      3391 8692 3387 8693 3386 8699
TIME...MOT...LOC 2134Z 165DEG 32KT 3393 8702

MAX HAIL SIZE...0.88 IN
MAX WIND GUST...50 MPH

30

Special Weather Statement
National Weather Service Huntsville AL
445 PM CDT Wed Oct 6 2021

ALZ006>009-016-062230-
Marshall AL-Madison AL-Morgan AL-Cullman AL-Jackson AL-
445 PM CDT Wed Oct 6 2021

...Strong thunderstorms will impact portions of west central Jackson,
northwestern Marshall, central Madison, northeastern Cullman and
northeastern Morgan Counties through 530 PM CDT...

At 444 PM CDT, Doppler radar was tracking strong thunderstorms along
a line extending from near Alabama A And M University to near Arab.
Movement was northwest at 5 mph.

HAZARD...Winds in excess of 40 mph and penny size hail.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects. Minor damage to outdoor objects is
         possible.

Locations impacted include...
Huntsville, Guntersville, Arab, Moores Mill, Meridianville, Owens
Cross Roads, Gurley, Woodville, Alabama A And M University and Paint
Rock.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Torrential rainfall is also occurring with these storms and may lead
to localized flooding. Do not drive your vehicle through flooded
roadways.

Frequent cloud to ground lightning is occurring with these storms.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.

A Tornado Watch remains in effect until 1000 PM CDT for north central
and northeastern Alabama.

&&

LAT...LON 3487 8657 3427 8656 3424 8628 3486 8629
TIME...MOT...LOC 2144Z 151DEG 5KT 3478 8650 3434 8647

MAX HAIL SIZE...0.75 IN
MAX WIND GUST...40 MPH

30