Alert archive / Alabama / Severe Thunderstorm Warnings in 2017

Severe Thunderstorm Warning 227, NWS Tallahassee, FL

July 13, 2017Houston County, Alabama; Jackson County, Florida

NWS Tallahassee, FL issued this severe thunderstorm warning at Jul 13, 2017, 7:16 PM CDT for Houston County, Alabama; Jackson County, Florida. It was in force for 29 min. 1 report came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued: Jul 13, 2017, 7:16 PM CDT (00:16 UTC)
Expired: Jul 13, 2017, 7:45 PM CDT
In force: 29 min
Issued by: NWS Tallahassee, FL
Area: Storm-based polygon
Hail: 0.75 in
Wind: 60.0 mph

Counties Houston County, AL, Jackson County, FL

The radar

The Ft Rucker radar (KEOX), 51 km from the middle of the area, began a volume at 00:20 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.

What was reported inside it

Time	Report	Where	Remark
Jul 13, 7:32 PM CDT	TSTM WND DMG	3 Nnw Cottonwood, AL	REPORTS OF POWER LINES AND A TREE DOWN AROUND SOUTH COUNTY RD 33

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

Did it verify

Verified. The Iowa Environmental Mesonet's Cow matched one storm report to this severe thunderstorm warning; the first came 16 minutes after it went out.

Cow counts a report within 15 km of the polygon while the warning was in force: a tornado for a tornado warning; hail of 1 inch or more, a gust of 58 mph or more or wind damage for a severe thunderstorm warning; a flash flood report for a flash flood warning.

The nearest sounding before it

Peachtre/Fal Fld, GA (KFFC), launched 00:00Z, 0.3 hours before the alert went out and 266 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 954 J/kg
Mixed-layer CIN: -11 J/kg
Mixed-layer LCL: 1642 m above ground
0-6 km bulk shear: 6 kt
0-1 km storm-relative helicity: 3 m²/s²
0-3 km storm-relative helicity: -16 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

015 
WUUS52 KTAE 140016
SVRTAE
ALC069-FLC063-140045-
/O.NEW.KTAE.SV.W.0227.170714T0016Z-170714T0045Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Tallahassee FL
716 PM CDT THU JUL 13 2017

The National Weather Service in Tallahassee has issued a

* Severe Thunderstorm Warning for...
  Eastern Houston County in southeastern Alabama...
  North central Jackson County in the Panhandle of Florida...

* Until 745 PM CDT

* At 716 PM CDT, severe thunderstorms were located along a line
  extending from near Cottonwood to 12 miles south of Ashford, moving
  west at 25 mph.

  HAZARD...60 mph wind gusts. 

  SOURCE...Radar indicated. 

  IMPACT...Expect damage to roofs, siding, and trees. 

* Locations impacted include...
  Cottonwood, Ashford, Cowarts, Malone, Avon, Pansey, Grangeburg,
  Lovetown and Sealy Springs.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

This is an EXTREMELY DANGEROUS SITUATION. These storms have produced 
widespread wind damage. SEEK SHELTER NOW inside a sturdy structure 
and stay away from windows!

&&

LAT...LON 3097 8507 3096 8524 3100 8537 3117 8533
      3126 8517
TIME...MOT...LOC 0016Z 105DEG 21KT 3108 8537 3101 8518 

HAIL...<.75IN
WIND...60MPH
 
$$

18-WOOL

What forecasters said that day

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

NWS Tallahassee, FL wrote its last area forecast discussion before this severe thunderstorm warning went out at Jul 13, 6:25 PM CDT, 51 minutes earlier.

Area forecast discussion, Jul 13, 6:25 PM CDT, 51 minutes before

Area Forecast Discussion
National Weather Service Tallahassee FL
725 PM EDT Thu Jul 13 2017

.AVIATION [Through 00Z Saturday]... An area of showers and
thunderstorms continues to push west this evening. VCTS will be
possible at DHN, ECP, ABY and TLH for the next several hours. MVFR
conditions are expected around sunrise at VLD, otherwise VFR will
prevail.

&&

.PREV DISCUSSION [407 PM EDT]...

.NEAR TERM [Through Tonight]...

The East coast sea breeze is more potent and has made it further
west earlier than normal this afternoon. Expect these storms to
continue to push west for the next few hours with coverage
decreasing after sunset. Overnight storms will favor the western
waters with PoPs 40-60% offshore. Lows tonight will be in the mid
70s.

.SHORT TERM [Friday Through Saturday Night]...

The western extent of the Bermuda Ridge will build across our
forecast area Friday, extending from the surface to the upper
levels. Mid-layer drying/subsidence associated with this feature
will limit the coverage of deep moist convection across our region,
with the greatest chance of rain across the FL Panhandle (30-40%
PoP) where there will still be adequate moisture. Elsewhere PoPs
will be 20% or less. An upper trough will begin to develop across
much of the eastern CONUS Saturday and Saturday night, and a
weakening surface cold front will stall across north-central GA
and AL. While we don't expect any synoptic scale forcing from the
trough, the prevailing wind field we be altered in such a way as
to increase deep-layer moisture somewhat across our region, and
shift the sea breeze circulation so that the rain chances will be
near average (30-40%) and fairly evenly distributed across the
area. It will be warm this weekend, with high temperatures in the
mid 90s and lows in the mid 70s.

.LONG TERM [Sunday Through Thursday]...

A mean deep-layer trough will be the main synoptic feature across
much of the Southeast, with moist southwest winds expected across
our forecast area. This is typically a favorable environment for the
development of scattered to numerous daytime thunderstorms as the
sea breeze fronts form and move inland. PoPs will be in the 30-50%
range (highest south) each afternoon, with slight rain chances
overnight. Temperatures will be near average with lows in the 70s
and highs in the lower to mid 90s.

.MARINE...

With a high pressure ridge near and north of the marine area, the
prevailing winds through Saturday will be east to southeast less
than 15 knots, with seas 3 feet or less. As the ridge becomes
centered over the coastal waters Sunday and Monday, winds will
become south to southwest 5 to 10 knots, with sea 2 feet or less.

.FIRE WEATHER...

There are no fire weather concerns for the next several days.

.HYDROLOGY...

A typical summertime pattern is expected, with locally heavy rains
possible, but organized heavy rain that would lead to river flooding
or flash flooding is unlikely.

&&

.PRELIMINARY POINT TEMPS/POPS...

Tallahassee   74  94  74  94  74 /  20  20  10  40  10
Panama City   77  90  77  90  77 /  30  40  10  30  10
Dothan        75  94  74  94  74 /  20  40  10  30  20
Albany        75  95  75  94  74 /  10  20  10  30  20
Valdosta      74  95  74  95  74 /  10  20  10  30  20
Cross City    74  94  74  94  74 /  10  20  10  20  10
Apalachicola  77  90  77  90  77 /  30  40  20  40  10

&&

.TAE WATCHES/WARNINGS/ADVISORIES...

FL...None.
GA...None.
AL...None.
GM...None.

&&

NEAR TERM...Weston
SHORT TERM...Fournier
LONG TERM...Fournier
AVIATION...Weston
MARINE...Fournier
FIRE WEATHER...Weston
HYDROLOGY...Fournier

In the hours before

Local storm report, Jul 13, 6:05 PM CDT, 1 hour 11 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE TALLAHASSEE FL
705 PM EDT THU JUL 13 2017

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

0647 PM     TSTM WND DMG     2 E HAVANA              30.63N 84.39W
07/13/2017                   GADSDEN            FL   911 CALL CENTER

            REPORT OF A TREE DOWN NEAR HAVANA

&&

RH

Local storm report, Jul 13, 6:06 PM CDT, 1 hour 10 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE TALLAHASSEE FL
706 PM EDT THU JUL 13 2017

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

0642 PM     TSTM WND DMG     2 W SCOTLAND            30.58N 84.46W
07/13/2017                   GADSDEN            FL   911 CALL CENTER

            REPORT OF A TREE DOWN NEAR SCOTLAND

&&

RH

Local storm report, Jul 13, 6:09 PM CDT, 1 hour 7 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE TALLAHASSEE FL
709 PM EDT THU JUL 13 2017

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

0647 PM     TSTM WND DMG     5 NNE QUINCY AIRPORT    30.66N 84.56W
07/13/2017                   GADSDEN            FL   911 CALL CENTER

            REPORT OF A TREE DOWN NEAR ATTAPULGUS HWY

&&

RH

Local storm report, Jul 13, 6:11 PM CDT, 1 hour 5 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE TALLAHASSEE FL
711 PM EDT THU JUL 13 2017

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

0647 PM     TSTM WND DMG     5 NE QUINCY AIRPORT     30.63N 84.51W
07/13/2017                   GADSDEN            FL   911 CALL CENTER

            REPORT OF A TREE DOWN ON MILLIGAN RD

&&

RH

Local storm report, Jul 13, 6:33 PM CDT, 43 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE TALLAHASSEE FL
733 PM EDT THU JUL 13 2017

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

0600 PM     TSTM WND DMG     2 SSW CENTERVILLE       30.54N 84.19W
07/13/2017                   LEON               FL   911 CALL CENTER

            TREE DOWN AT JAMAICA CT. AND PIMLICO DR.

&&

EWESTON

Local storm report, Jul 13, 6:34 PM CDT, 42 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE TALLAHASSEE FL
734 PM EDT THU JUL 13 2017

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

0600 PM     TSTM WND DMG     ESE BRADFORDVILLE       30.56N 84.21W
07/13/2017                   LEON               FL   911 CALL CENTER

            TREE DOWN AT VELDA DAIRY ROAD AND VELDA DAIRY DRIVE

&&

EWESTON

The office that day

Everything else NWS Tallahassee, FL issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jul 13, 7:33 PM CDT	Special Weather Statement	TAE	Houston	57 min
Jul 14, 2:29 PM CDT	Special Weather Statement	TAE	Dale	46 min
Jul 14, 3:16 PM CDT	Special Weather Statement	TAE	Dale	44 min
Jul 14, 3:24 PM CDT	Severe Thunderstorm Warning	TAE	Dale, Henry	20 min
Jul 13, 7:29 PM CDT	Severe Thunderstorm Warning	TAE	Bay, Jackson, Washington	17 min
Jul 14, 6:13 AM CDT	Special Marine Warning	TAE		47 min
Jul 14, 11:09 AM CDT	Special Weather Statement	TAE	Bay	51 min
Jul 14, 11:15 AM CDT	Special Weather Statement	TAE	Bay	45 min
Jul 14, 11:33 AM CDT	Severe Thunderstorm Warning	TAE	Bay, Walton, Washington	42 min
Jul 14, 11:38 AM CDT	Special Marine Warning	TAE		97 min
Jul 14, 12:03 PM CDT	Severe Thunderstorm Warning	TAE	Holmes, Walton, Washington	57 min
Jul 14, 12:56 PM CDT	Special Weather Statement	TAE	Holmes	49 min

Nearby

Severe Thunderstorm Warnings in Alabama, 2017 Severe Thunderstorm Warnings in Florida, 2017 Every severe thunderstorm warning in 2017

Sources

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