Alert archive / Alabama / Special Marine Warnings in 2018

Special Marine Warning 310, NWS Mobile, AL

December 13, 2018

NWS Mobile, AL issued this special marine warning at Dec 13, 2018, 5:50 PM CST. It was in force for 85 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
Dec 13, 2018, 5:50 PM CST (23:50 UTC)
Expired
Dec 13, 2018, 7:15 PM CST
In force
85 min
Issued by
NWS Mobile, AL
Area
Storm-based polygon
Hail
0.0 in
Wind
34.0 mph

The radar

The Mobile radar (KMOB), 87 km from the middle of the area, began a volume at 23:55 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

Slidell Radar S, LA (KSIL), launched 12:00Z, 11.8 hours before the alert went out and 162 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, Slidell Radar S, LA at 12:00Z on 2018-12-13Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 11 joules per kilogram.LCLLFCEL10008507005003002001001 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, Slidell Radar S, LA at 12:00Z on 2018-12-13The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 216 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
11 J/kg
Mixed-layer CIN
-56 J/kg
Mixed-layer LCL
972 m above ground
0-6 km bulk shear
36 kt
0-1 km storm-relative helicity
216 m²/s²
0-3 km storm-relative helicity
247 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

262 
WHUS54 KMOB 132350
SMWMOB
GMZ650-670-140115-
/O.NEW.KMOB.MA.W.0310.181213T2350Z-181214T0115Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Special Marine Warning
National Weather Service Mobile AL
550 PM CST THU DEC 13 2018

The National Weather Service in Mobile has issued a

* Special Marine Warning for...
  Coastal waters from Pensacola FL to Pascagoula MS out 20 NM...
  Waters from Pensacola FL to Pascagoula MS from 20 to 60 NM...

* Until 715 PM CST.

* At 549 PM CST, a strong thunderstorm capable of producing
  waterspouts was located 38 nm south of Farewell Buoy, moving north
  at 25 knots.

  HAZARD...Waterspouts and wind gusts 34 knots or greater.

  SOURCE...Radar.

  IMPACT...Waterspouts can easily overturn boats and create locally 
           hazardous seas. Small craft could be damaged in briefly 
           higher winds and suddenly higher waves.

* The strong thunderstorm will remain over mainly open waters.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Thunderstorms can produce sudden waterspouts. Waterspouts can easily 
overturn boats and create locally hazardous seas. Seek safe harbor 
immediately.

&&

LAT...LON 3009 8779 2941 8807 2988 8831 3007 8835
TIME...MOT...LOC 2349Z 197DEG 23KT 2949 8812 

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

$$
1 follow-up statement
444 
FZUS74 KMOB 140038
MWSMOB

Marine Weather Statement
National Weather Service Mobile AL
638 PM CST THU DEC 13 2018

GMZ650-670-140115-
/O.CON.KMOB.MA.W.0310.000000T0000Z-181214T0115Z/
638 PM CST THU DEC 13 2018

...A SPECIAL MARINE WARNING REMAINS IN EFFECT UNTIL 715 PM CST...

For the following areas...
Coastal waters from Pensacola FL to Pascagoula MS out 20 NM...
Waters from Pensacola FL to Pascagoula MS from 20 to 60 NM...

At 638 PM CST, a severe thunderstorm capable of producing waterspouts
was located 23 nm south of Farewell Buoy, moving north at 20 knots.

HAZARD...Waterspouts and wind gusts 34 knots or greater.

SOURCE...Radar indicated.

IMPACT...Waterspouts can easily overturn boats and create locally 
         hazardous seas. Small craft could be damaged in briefly 
         higher winds and suddenly higher waves.

The severe thunderstorm will remain over mainly open waters.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Thunderstorms can produce sudden waterspouts. Waterspouts can easily
overturn boats and create locally hazardous seas. Seek safe harbor
immediately.

&&

LAT...LON 2971 8795 2974 8824 2988 8831 3007 8835
      3009 8779
TIME...MOT...LOC 0038Z 194DEG 20KT 2975 8794 

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

$$

The office that day

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

IssuedProductOfficeCountiesLasted
Dec 13, 5:32 AM CSTHigh Surf AdvisoryMOBBaldwin, Mobile51 hr
Dec 13, 4:16 PM CSTSpecial Marine WarningMOB89 min
Dec 13, 4:58 PM CSTSpecial Marine WarningMOB62 min
Dec 13, 5:43 PM CSTSpecial Marine WarningMOB47 min

Nearby

Special Marine Warnings in Alabama, 2018Every special marine warning in 2018

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.