Special Weather Statement, NWS Huntsville, AL

Area Forecast Discussion
National Weather Service Huntsville AL
1147 PM CDT Tue Jul 30 2024

...New AVIATION...

.NEAR TERM...
(Tonight)
Issued at 834 PM CDT Tue Jul 30 2024

Luckily, the MCS that brought many strong to severe thunderstorms
to central and eastern TN into central Georgia earlier this
afternoon and early this evening moved just east of northern AL
and our southern middle Tennessee counties.

A weak convergence boundary extends NNW west from that activity
just east of the I-65 corridor. Only isolated to scattered showers
(mainly isolated) have occurred along this boundary this evening.

However, upstream of our area a second convective complex has
formed over southwestern Kentucky that is moving southeast towards
the area. Additional scattered strong to severe thunderstorms
have already developed in north central Tennessee ahead of this
activity. HRRR and RAP14 seem to show an increase in 700 mb
forcing pushing into southern middle Tennessee between 3Z and 6Z.
Expect this is likely with that complex of convection moving
southeast at this time.

The storm complex will be moving into an unstable airmass even
into the 10 PM to midnight period based on current dewpoints and
model forecast CAPE. Given forecast shear of 25 to 35 knots
possibly clipping areas near and east of the I-65 corridor when
this convection moves into southern middle Tennessee, think a
strong to severe thunderstorm potential could continue later
between 11 PM and 4 AM as this activity moves into southern middle
Tennessee and into northern Alabama. Damaging winds and frequent
lighting would be the main threats, but small hail could occur. A
watch severe thunderstorm watch will be issued shortly that will
be in effect through 2 AM. This watch may be extended if the
convective storms hold their intensity overnight. Thus, have
increase Pop to between 30 and 60 percent toward midnight into the
3 or 4 AM timeframe near and east of the I-65 corridor. There is
some question how far west this activity will extend at this time.

&&

.SHORT TERM...
(Wednesday through Thursday)
Issued at 110 PM CDT Tue Jul 30 2024

On Wednesday, the upr ridge will expand farther eastward into the
OH/TN Valley regions. This will lead to an increased risk for hot
temperatures and dangerous heat indices as a high dew point air
mass remains in the region. Heat indices are likely to exceed 105
F in most locations on Wed afternoon. The same can be said for
Thursday as the ridge and low-lvl temps increase perhaps a bit
further ahead of a short wave beginning to dig into the Midwest
from the norther. The expansion of the ridge will tend to
encapsulate the region in a more westerly upr flow regime, more
effectively pushing NW flow and chances for showers and
thunderstorms mainly to our east. Due to uncertainty with the
specific extension of the ridging and potential for outflows from
convection, we have retained slight chance/chance POPs in the east
for both days. Due to increased confidence in meeting heat
advisory criteria, a Heat Advisory has been issued for all
counties for tomorrow and into Thursday.

&&

.LONG TERM...
(Thursday night through Monday)
Issued at 200 AM CDT Tue Jul 30 2024

Friday looks to be the last day of heat indices near or exceeding
Heat Advisory criteria as high pressure begins to retrograde to the
west. This will place us under the influences of NW flow, a more
favorable pattern for additional rain and storms. Low PoPs are
introduced Friday afternoon and maintained through the weekend as a
trough swings through the Ohio Valley. Diurnal heating will be able
to take advantage of the favorable pattern allowing for scattered
showers and storms each afternoon. While there are no significant
severe signals right now, this weekend will need to be monitored
through the week for MCS potential given the favorable pattern.
Models indicate high pressure building back east through the day on
Monday with flow transitioning to the NNE.

&&

.AVIATION...
(06Z TAFS)
Issued at 1147 PM CDT Tue Jul 30 2024

VFR conditions are expected through the TAF period. A tempo group
was included for CIGS around 6000 feet between 6Z and 09Z at both
terminals. Then expect clouds to scatter out with some VSBYS
reductions due to fog possible after 11Z. If confidence in -SHRA
or -TSRA during that tempo group then lower VSBYS or CIGS might be
added to the tempo group in future amendments.

&&

.HUN WATCHES/WARNINGS/ADVISORIES...
AL...Heat Advisory from noon Wednesday to 7 PM CDT Thursday for
     ALZ001>010-016.

TN...Heat Advisory from noon Wednesday to 7 PM CDT Thursday for
     TNZ076-096-097.

&&

NEAR TERM...KTW
SHORT TERM....KDW
LONG TERM....RAD
AVIATION...KTW

Special Weather Statement
National Weather Service Huntsville AL
1228 AM CDT Wed Jul 31 2024

TNZ076-096-097-310615-
Franklin TN-Moore TN-Lincoln TN-
1228 AM CDT Wed Jul 31 2024

...STRONG THUNDERSTORMS WILL IMPACT MOORE...EASTERN LINCOLN AND
FRANKLIN COUNTIES THROUGH 115 AM CDT...

At 1228 AM CDT, Doppler radar was tracking strong thunderstorms along
a line extending from near Shelbyville to 7 miles northwest of
Lynchburg to Petersburg. Movement was southeast at 30 mph.

HAZARD...Wind gusts up to 40 mph.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects.

Locations impacted include...
Winchester, Fayetteville, Lynchburg, Decherd, Estill Springs, Cowan,
Huntland, Tims Ford Lake, Sewanee, and Lincoln.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

These storms 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 Severe Thunderstorm Watch remains in effect until 200 AM CDT for
Middle Tennessee.

&&

LAT...LON 3539 8628 3538 8625 3537 8627 3534 8624
      3533 8620 3536 8616 3535 8608 3519 8586
      3517 8586 3499 8605 3499 8655 3529 8670
      3533 8660 3537 8659 3536 8649 3533 8646
      3532 8642 3535 8641 3536 8633 3541 8626
TIME...MOT...LOC 0528Z 331DEG 24KT 3549 8641 3536 8645 3530 8662

MAX HAIL SIZE...0.00 IN
MAX WIND GUST...40 MPH

AMP

Special Weather Statement
National Weather Service Huntsville AL
107 AM CDT Wed Jul 31 2024

ALZ009-TNZ097-310645-
Jackson AL-Franklin TN-
107 AM CDT Wed Jul 31 2024

...A STRONG THUNDERSTORM WILL IMPACT NORTHERN JACKSON AND SOUTHERN
FRANKLIN COUNTIES THROUGH 145 AM CDT...

At 106 AM CDT, Doppler radar was tracking a strong thunderstorm 11
miles northwest of Stevenson, or 15 miles west of Bridgeport, moving
southeast at 25 mph.

HAZARD...Wind gusts up to 40 mph.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects.

Locations impacted include...
Scottsboro, Winchester, Bridgeport, Decherd, Stevenson, Cowan,
Hollywood, Huntland, Skyline, and Tims Ford Lake.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

A Severe Thunderstorm Watch remains in effect until 200 AM CDT for
Middle Tennessee.

&&

LAT...LON 3482 8563 3461 8604 3492 8627 3494 8626
      3500 8632 3508 8632 3525 8609 3510 8586
      3499 8586 3499 8568 3493 8560 3488 8559
      3486 8559
TIME...MOT...LOC 0606Z 321DEG 24KT 3497 8598

MAX HAIL SIZE...0.00 IN
MAX WIND GUST...40 MPH

RAD