Alert archive / Alabama / Special Marine Warnings in 2021

Special Marine Warning 13, NWS Mobile, AL

January 7, 2021

NWS Mobile, AL issued this special marine warning at Jan 7, 2021, 11:08 AM CST. It was in force for 37 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
Jan 7, 2021, 11:08 AM CST (17:08 UTC)
Expired
Jan 7, 2021, 11:45 AM CST
In force
37 min
Issued by
NWS Mobile, AL
Area
Storm-based polygon
Hail
0.0 in
Wind
34.0 mph

The nearest sounding before it

Tallahassee Rgnl, FL (KTLH), launched 12:00Z, 5.1 hours before the alert went out and 182 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, Tallahassee Rgnl, FL at 12:00Z on 2021-01-07Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Tallahassee Rgnl, FL at 12:00Z on 2021-01-07The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 197 square meters per square second.1939587897Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1457 m above ground
0-6 km bulk shear
39 kt
0-1 km storm-relative helicity
197 m²/s²
0-3 km storm-relative helicity
241 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

772 
WHUS54 KMOB 071708
SMWMOB
GMZ636-071745-
/O.NEW.KMOB.MA.W.0013.210107T1708Z-210107T1745Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Special Marine Warning
National Weather Service Mobile AL
1108 AM CST Thu Jan 7 2021

The National Weather Service in Mobile has issued a

* Special Marine Warning for...
  Eastern Choctawhatchee Bay...

* Until 1145 AM CST.

* At 1108 AM CST, a strong thunderstorm was located 7 nm southeast of
  Santa Rosa Beach, moving northeast at 35 knots.

  HAZARD...Wind gusts 34 knots or greater.

  SOURCE...Radar.

  IMPACT...Small craft could be damaged in briefly higher winds and 
           suddenly higher waves.

* Locations impacted include...
  East Choctawhatchee Bay and Highway 331 Bridge. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Move to safe harbor immediately as gusty winds and high waves are
expected.

&&

LAT...LON 3043 8625 3043 8626 3042 8626 3040 8623
      3042 8631 3049 8625 3049 8620 3045 8619
      3047 8614 3043 8615 3045 8608 3042 8609
      3040 8610
TIME...MOT...LOC 1708Z 212DEG 36KT 3027 8618 

HAIL...0.00IN
WIND...>34KTS

$$
1 follow-up statement
156 
FZUS74 KMOB 071741
MWSMOB

Marine Weather Statement
National Weather Service Mobile AL
1141 AM CST Thu Jan 7 2021

GMZ636-071750-
/O.EXP.KMOB.MA.W.0013.000000T0000Z-210107T1745Z/
1141 AM CST Thu Jan 7 2021

...THE SPECIAL MARINE WARNING WILL EXPIRE AT 1145 AM CST...

The affected areas were... 
Eastern Choctawhatchee Bay...

The showers are moving away and no longer poses a significant threat 
to boaters.

LAT...LON 3043 8625 3043 8626 3042 8626 3040 8623
      3042 8631 3049 8625 3049 8620 3045 8619
      3047 8614 3043 8615 3045 8608 3042 8609
      3040 8610
TIME...MOT...LOC 1740Z 212DEG 36KT 3053 8600 

$$

The office that day

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

IssuedProductOfficeCountiesLasted
Jan 7, 4:44 AM CSTSpecial Marine WarningMOB91 min
Jan 7, 6:14 AM CSTSpecial Marine WarningMOB2 hr
Jan 7, 6:46 AM CSTSpecial Marine WarningMOB29 min
Jan 7, 8:05 AM CSTSpecial Marine WarningMOB55 min

Nearby

Special Marine Warnings in Alabama, 2021Every special marine warning 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.