Alert archive / Alabama / Special Weather Statements in 2021

Special Weather Statement, NWS Huntsville, AL

May 4, 2021Madison County, Alabama

NWS Huntsville, AL issued this special weather statement at May 4, 2021, 5:56 PM CDT for Madison County, Alabama. It was in force for 49 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued
May 4, 2021, 5:56 PM CDT (22:56 UTC)
Expired
May 4, 2021, 6:45 PM CDT
In force
49 min
Issued by
NWS Huntsville, AL

County Madison County, AL

The radar

The Northeast Alabama radar (KHTX), 37 km from the middle of the area, began a volume at 23:00 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

The nearest sounding before it

Birmingham, AL (KBMX), launched 12:00Z, 10.9 hours before the alert went out and 184 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-pSkew-T log-p diagram, Birmingham, AL at 12:00Z on 2021-05-04Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2158 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Birmingham, AL at 12:00Z on 2021-05-04The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 145 square meters per square second.19395878Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
2158 J/kg
Mixed-layer CIN
-5 J/kg
Mixed-layer LCL
569 m above ground
0-6 km bulk shear
28 kt
0-1 km storm-relative helicity
145 m²/s²
0-3 km storm-relative helicity
195 m²/s²
Significant tornado parameter
1.4
Supercell composite
7.3

Open this sounding in Storm Lab

The text

As transmitted.

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What forecasters said that day

The local office's own words before this special weather statement went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Huntsville, AL wrote its last area forecast discussion before this special weather statement went out at May 4, 2:20 PM CDT, 3 hours 36 minutes earlier.

Area forecast discussion, May 4, 2:20 PM CDT, 3 hours 36 minutes before
Area Forecast Discussion
National Weather Service Huntsville AL
220 PM CDT Tue May 4 2021

.NEAR TERM...(This Evening and Tonight)
Issued at 220 PM CDT Tue May 4 2021

Morning storms have waned as the initial cold pool boundary has
sagged southward into central Alabama. At the moment, this has kept
much of northern Alabama and southern middle Tennessee in a rain-
cooled, stable environment. However, we continue to monitor the
potential for a second round of thunderstorms -- some which could be
strong to severe late this afternoon and evening. Current satellite
trends over northeastern Mississippi into far northwestern Alabama
indicate some clearing is occurring -- with some rapid
destabilization noted just to our west (SBCAPE values of 2000-3000
J/kg and low-level lapse rates of 7.5 C/km). Despite much of northern
Alabama being under an anvil plume (from convection to the
southeast), feel that at least some partial clearing seems
plausible, especially over our western areas. Thus, we should get
enough heat/destabilization for storms to become surface-based in
these areas late in the day.

Another concern for the potential for a second round of storms
involves an impressive upper-level jetstreak nosing into western
Tennessee that is currently driving the storms (albeit in a much
more unstable environment) across northern/western Mississippi. This
feature may help force the aforementioned tongue of instability/high
theta-e values northeast into western portions of our area and serve
as a strong forcing mechanism for additional convection to develop
within this air mass across much of northern mississippi and into
western and north central Alabama by late this afternoon and evening.
The greatest severe threat will be to our south and west (in the
more unstable environment), but think there may be enough ingredients
in place to warrant messaging for some strong to severe storms
(especially in the western half of our area). Damaging winds and
marginally severe hail will be the main threats, though localized
flooding will also be a concern. Additionally, can't rule out a
tornado or two.

These storms should out pace the cold front, and move through the
area rather quickly during the evening hours, clearing our eastern
zones by 03z. Thereafter, rain will gradually taper off -- though low
stratus will likely remain in place for the remainder of the night.
Cooler air will begin to advect into the area by early Wednesday
morning with temperatures falling into the upper 50s.

.SHORT TERM...(Wednesday through Thursday)
Issued at 220 PM CDT Tue May 4 2021

High pressure will begin to build into the area from the northwest as
a cool, dry air mass becomes established across the region. Morning
clouds may be tough to erode at first underneath the inversion on
Wednesday morning, but expect some clearing by the afternoon. Breezy
northerly flow will reinforce the cool air mass and highs will
struggle to climb much above the 70 degree mark. Expect more of the
same for Thursday, with highs in the lower 70s once again despite
ample sunshine.

.LONG TERM...(Thursday night through Monday)
Issued at 220 PM CDT Tue May 4 2021

A large area of high pressure will continue to build into the
southeast on Friday. Very amplified northwest flow will provide some
cool and dry air for this time of year with highs only climbing into
the upper 60s to lower 70s based on 925-850 mb temperatures (despite
abundant sunshine). One more cool night (for May) expected though
with lows dropping into the upper 40s/lower 50s Friday night.

The area of high pressure is quickly modified by southwest flow that
develops ahead of a developing area of low pressure over the
midwestern states on Saturday. Some guidance shows very light QPF
with a warm front ahead of that area of low pressure during the day
on Saturday in our Tennessee counties, but based on sounding
profiles, think this will be mainly high clouds and virga.
Temperatures, despite some fairly persistent thicker cloud cover,
will be able to rebound into the upper 75 to 80 degree range in most
locations. Lows with continued cloud cover and stronger winds will
likely only drop into the upper 50s to lower 60s overnight.

The warm air advection continues to increase ahead of the area of low
pressure as it moves further east on Sunday. Most guidance depicts
rain chances pushing back into the area during the morning hours on
Sunday and spreading east across northern Alabama. Despite this, it
will continue to get warmer with highs in the upper 70s to lower 80s.

Models differ in timing of impulses along the warm front associated
with this surface low and how exactly if waffles north of south,
before the low pushes through the area towards the end of next week.
Either way though, a wet pattern seems to be shaping up Sunday
through Wednesday of next week with scattered to more numerous
showers and thunderstorms possible at times during that period. Could
be some stronger storms as well Tuesday or Wednesday, but too far
out to say more than that. With the cloud cover and increased chances
of precipitation, highs should be a bit cooler, primarily in the
upper 70s. Lows should stay warm in the upper 50s to 60s Monday
through Wednesday.

&&

.AVIATION...(For the 18Z TAFS through 18Z Wednesday afternoon)
Issued at 1239 PM CDT Tue May 4 2021

Periods of SHRA and TSRA will impact the region through early this
evening as a cold front moves through the Tennessee valley. These
storms will produce MVFR to IFR conditions, locally, due to reduced
visibilities and ceilings as well as gusty winds should they impact
either terminal. Amendments may be required. Storms will taper off
this evening behind the front, but expect MVFR ceilings to remain in
place for much of the rest of the period as winds veer to the
northwest.

&&

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

NEAR TERM...AMP.24
SHORT TERM...AMP.24
LONG TERM...KTW
AVIATION...AMP.24

For more information please visit our website
at weather.gov/huntsville.
Hazardous weather outlook, May 4, 1:08 PM CDT, 4 hours 48 minutes before
Hazardous Weather Outlook
National Weather Service Huntsville AL
108 PM CDT Tue May 4 2021

ALZ001>010-016-TNZ076-096-097-050915-
Lauderdale-Colbert-Franklin AL-Lawrence-Limestone-Madison-Morgan-
Marshall-Jackson-DeKalb-Cullman-Moore-Lincoln-Franklin TN-
108 PM CDT Tue May 4 2021

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

.DAY ONE...This Afternoon through Tonight...

Another round of strong to severe storms will be possible late this
afternoon and evening along and ahead of a cold front. Damaging winds
and marginally severe hail will be the primary threats. A tornado or
two cannot be ruled out. Additionally, heavy rainfall and localized
flash flooding will be possible with any of these storms.

.DAYS TWO THROUGH SEVEN...Wednesday through Monday...

The probability for widespread hazardous weather is low.

A few thunderstorms are possible Sunday into Monday.

.SPOTTER INFORMATION STATEMENT...

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

Please relay any information about observed severe weather to the
NWS while following all local, state, and CDC guidelines.

In the hours before

Local storm report, May 4, 2:29 PM CDT, 3 hours 27 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE HUNTSVILLE AL
229 PM CDT TUE MAY 4 2021

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

0710 AM     TSTM WND DMG     2 NW GOOD HOPE          34.12N 86.89W
05/04/2021                   CULLMAN            AL   EMERGENCY MNGR

            4/5 BROKEN POWER POLES AND TREES DOWN AT
            THIS LOCATION.

&&

KTW
Local storm report, May 4, 2:31 PM CDT, 3 hours 25 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE HUNTSVILLE AL
231 PM CDT TUE MAY 4 2021

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

0704 AM     TSTM WND DMG     7 WSW GOOD HOPE         34.06N 86.97W
05/04/2021                   CULLMAN            AL   PUBLIC

            TREE DOWN AT THE INTERSECTION OF CR 291 AND
            292.

&&

KTW
Special weather statement, May 4, 3:37 PM CDT, 2 hours 19 minutes before
Special Weather Statement
National Weather Service Huntsville AL
337 PM CDT Tue May 4 2021

ALZ003-042100-
Franklin AL-
337 PM CDT Tue May 4 2021

...SIGNIFICANT WEATHER ADVISORY FOR WESTERN FRANKLIN COUNTY UNTIL 400
PM CDT...

At 336 PM CDT, Doppler radar was tracking strong thunderstorms along
a line extending from near Fairview to near Tremont. Movement was
east at 30 mph.

Wind gusts up to 50 mph will be possible with these storms.

Locations impacted include...
Red Bay, Belgreen, Vina, Hodges, Cedar Creek Reservoir, Atwood,
Dempsey, Duketon, Little Bear Creek Reservoir and Halltown.

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.

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.

&&

LAT...LON 3451 8815 3455 8781 3431 8783 3431 8795
      3432 8817
TIME...MOT...LOC 2036Z 271DEG 28KT 3442 8827 3425 8828

KDW
Special weather statement, May 4, 4:18 PM CDT, 1 hour 38 minutes before
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Special weather statement, May 4, 5:10 PM CDT, 46 minutes before
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Special weather statement, May 4, 5:56 PM CDT, 0 minutes before
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The office that day

Everything else NWS Huntsville, AL issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 4, 7:18 AM CDTSpecial Weather StatementHUNColbert42 min
May 4, 7:45 AM CDTSpecial Weather StatementHUNCullman60 min
May 4, 8:31 AM CDTSpecial Weather StatementHUNLimestone, Madison, Morgan44 min
May 4, 9:01 AM CDTSpecial Weather StatementHUNJackson44 min
May 4, 9:04 AM CDTSevere Thunderstorm WarningHUNJackson26 min
May 4, 9:23 AM CDTSpecial Weather StatementHUNDeKalb52 min
May 4, 9:25 AM CDTSpecial Weather StatementHUNCullman, Morgan50 min
May 4, 9:31 AM CDTSevere Thunderstorm WarningHUNCullman, Morgan39 min
May 4, 9:39 AM CDTSevere Thunderstorm WarningHUNDeKalb, Jackson36 min
May 4, 9:51 AM CDTSevere Thunderstorm WarningHUNDeKalb24 min
May 4, 10:17 AM CDTSpecial Weather StatementHUNDeKalb58 min
May 4, 10:47 AM CDTFlash Flood WarningHUNDeKalb, Marshall3 hr
May 4, 10:51 AM CDTSpecial Weather StatementHUNMarshall39 min
May 4, 11:15 AM CDTSpecial Weather StatementHUNCullman45 min
May 4, 11:18 AM CDTSevere Thunderstorm WarningHUNCullman42 min
May 4, 3:37 PM CDTSpecial Weather StatementHUNFranklin23 min
May 4, 4:18 PM CDTSpecial Weather StatementHUNLauderdale27 min
May 4, 5:10 PM CDTSpecial Weather StatementHUNCullman35 min
May 4, 6:01 PM CDTSpecial Weather StatementHUNMarshall44 min
May 4, 6:16 PM CDTSpecial Weather StatementHUNMadison44 min
May 4, 7:16 AM CDTSpecial Weather StatementHUNLincoln, Moore59 min
May 4, 7:38 AM CDTSevere Thunderstorm WarningHUNLincoln, Moore40 min
May 4, 8:03 AM CDTSpecial Weather StatementHUNFranklin42 min

Nearby

Special Weather Statements in Alabama, 2021Every special weather statement in 2021

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.