Alert archive / California / Special Marine Warnings in 2017

Special Marine Warning 21, NWS Eureka, CA

December 19, 2017

NWS Eureka, CA issued this special marine warning at Dec 19, 2017, 2:53 PM PST. It was in force for 22 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 19, 2017, 2:53 PM PST (22:53 UTC)
Expired
Dec 19, 2017, 3:15 PM PST
In force
22 min
Issued by
NWS Eureka, CA
Area
Storm-based polygon
Hail
0.0 in
Wind
40.0 mph

The radar

The Eureka (Bunker Hill) radar (KBHX), 79 km from the middle of the area, began a volume at 22:55 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

Medford/Jackson, OR (KMFR), launched 12:00Z, 10.9 hours before the alert went out and 172 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, Medford/Jackson, OR at 12:00Z on 2017-12-19Temperature 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°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Medford/Jackson, OR at 12:00Z on 2017-12-19The 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1152 m above ground
0-6 km bulk shear
54 kt
0-1 km storm-relative helicity
145 m²/s²
0-3 km storm-relative helicity
279 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

221 
WHUS56 KEKA 192253
SMWEKA
PZZ450-455-470-192315-
/O.NEW.KEKA.MA.W.0021.171219T2253Z-171219T2315Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Special Marine Warning
National Weather Service Eureka CA
253 PM PST TUE DEC 19 2017

The National Weather Service in Eureka California has issued a

* Special Marine Warning for...
  Coastal waters from Cape Mendocino to Pt. Arena CA out 10 nm...
  Coastal waters from Pt. St. George to Cape Mendocino CA out 10
  nm...
  Waters from Pt. St. George to Cape Mendocino CA from 10 to 60 nm...

* Until 315 PM PST

* At 250 PM PST, strong showers were located along a line extending 
  from 13 nm east of Crescent City to 29 nm northwest of Cape 
  Mendocino, moving east at 30 knots.

  HAZARD...Wind gusts to 40 knots. 

  SOURCE...Radar indicated. 

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

* Locations impacted include...
  Crescent City and Trinidad Head. 

LAT...LON 4168 12414 4157 12410 4152 12398 4151 12396
      4151 12397 4147 12394 4147 12395 4154 12405
      4154 12408 4136 12407 4114 12416 4097 12412
      4066 12430 4062 12429 4062 12430 4052 12438
      4033 12442 4074 12489 4168 12428
TIME...MOT...LOC 2250Z 252DEG 36KT 4182 12391 4072 12494 

HAIL...0.00IN
WIND...40KTS

$$

Nearby

Special Marine Warnings in California, 2017Every special marine 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.