Alert archive / Washington / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 1, NWS Seattle, WA

January 13, 20215 counties in Washington

NWS Seattle, WA issued this severe thunderstorm warning at Jan 13, 2021, 12:19 AM PST for 5 counties in Washington. It was in force for 39 min. 8 reports 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
Jan 13, 2021, 12:19 AM PST (08:19 UTC)
Expired
Jan 13, 2021, 12:58 AM PST
In force
39 min
Issued by
NWS Seattle, WA
Area
Storm-based polygon
Hail
0.75 in
Wind
60.0 mph

Counties Island County, WA, Jefferson County, WA, San Juan County, WA, Skagit County, WA, Snohomish County, WA

The radar

The Seattle radar (KATX), 11 km from the middle of the area, began a volume at 08:22 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

TimeReportWhereRemark
Jan 13, 12:19 AM PSTTSTM WND GST 544 N Oak Harbor, WACORRECTS PREVIOUS NON-TSTM WND GST REPORT FROM 4 N OAK HARBOR. AWOS STATION KNUW WHIDBEY ISLAND NAS.
Jan 13, 12:19 AM PSTNON-TSTM WND GST 544 N Oak Harbor, WAAWOS STATION KNUW WHIDBEY ISLAND NAS.
Jan 13, 12:34 AM PSTNON-TSTM WND GST 547 E Friday Harbor, WAMESONET STATION DW7371 LOPEZ ISLAND.
Jan 13, 12:35 AM PSTTSTM WND GST 623 Wsw Coupeville, WACORRECTS PREVIOUS NON-TSTM WND GST REPORT FROM 3 WSW COUPEVILLE.
Jan 13, 12:35 AM PSTNON-TSTM WND GST 623 Wsw Coupeville, WA
Jan 13, 12:50 AM PSTNON-TSTM WND GST 489 Wsw Anacortes, WAMESONET STATION 7975D 9 W ANACORTES.
Jan 13, 12:56 AM PSTNON-TSTM WND GST 644 N Oak Harbor, WAAWOS STATION KNUW WHIDBEY ISLAND NAS.
Jan 13, 1:06 AM PSTNON-TSTM WND GST 564 Ne Swinomish Village, WAMESONET STATION TAVON 4.6 NE LA CONNER (WA DOT).

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

The nearest sounding before it

Quillayute State, WA (KUIL), launched 00:00Z, 8.3 hours before the alert went out and 150 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, Quillayute State, WA at 00:00Z on 2021-01-13Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2 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, Quillayute State, WA at 00:00Z on 2021-01-13The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 267 square meters per square second.1939587897117136156Sfc1 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
2 J/kg
Mixed-layer CIN
-15 J/kg
Mixed-layer LCL
470 m above ground
0-6 km bulk shear
87 kt
0-1 km storm-relative helicity
267 m²/s²
0-3 km storm-relative helicity
455 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

991 
WUUS56 KSEW 130819
SVRSEW
WAC029-031-055-057-061-130915-
/O.NEW.KSEW.SV.W.0001.210113T0819Z-210113T0915Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Seattle WA
1219 AM PST Wed Jan 13 2021

The National Weather Service in Seattle has issued a

* Severe Thunderstorm Warning for...
  Northwestern Snohomish County in west central Washington...
  Southeastern San Juan County in northwestern Washington...
  Northeastern Jefferson County in northwestern Washington...
  Northern Island County in northwestern Washington...
  Western Skagit County in northwestern Washington...

* Until 115 AM PST

* At 1217 AM PST, a line of showers producing strong winds was 
  located near Oak Harbor, moving east at 55 mph.

  HAZARD...60 mph wind gusts. 

  SOURCE...Radar indicated. 

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

* Locations impacted include...
  Marysville, Mount Vernon, Oak Harbor, Arlington, Anacortes,
  Sedro-Woolley, Port Townsend, Burlington, Stanwood, Lake Mcmurray,
  Lake Ketchum, Lake Goodwin, Camano, La Conner, Stimson Crossing,
  Big Lake, Weallup Lake, Smokey Point, John Sam Lake and Warm Beach.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

Wind damage with this storm will occur without lightning.
Do not wait for the sound of thunder before taking cover. SEEK
SHELTER IMMEDIATELY inside a sturdy structure and stay away from
windows.

&&

LAT...LON 4809 12213 4810 12234 4824 12244 4809 12238
      4809 12252 4832 12240 4845 12257 4829 12251
      4823 12273 4809 12256 4811 12259 4816 12269
      4808 12288 4842 12265 4842 12289 4852 12293
      4858 12264 4846 12250 4858 12261 4865 12233
TIME...MOT...LOC 0817Z 260DEG 47KT 4838 12266 

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

PULLIN
1 follow-up statement
985 
WWUS56 KSEW 130858
SVSSEW

Severe Weather Statement
National Weather Service Seattle WA
1258 AM PST Wed Jan 13 2021

WAC029-031-055-057-061-130907-
/O.CAN.KSEW.SV.W.0001.000000T0000Z-210113T0915Z/
Snohomish-San Juan-Jefferson-Island-Skagit-
1258 AM PST Wed Jan 13 2021

...THE SEVERE THUNDERSTORM WARNING FOR NORTHWESTERN SNOHOMISH...
SOUTHEASTERN SAN JUAN...NORTHEASTERN JEFFERSON...NORTHERN ISLAND AND
WESTERN SKAGIT COUNTIES IS CANCELLED...
        
The storm which prompted the warning has weakened below severe
limits, and has exited the warned area. Therefore, the warning has 
been cancelled.  However gusty winds of 40 to 50 mph at times are 
still possible across these areas for the next several hours.

LAT...LON 4809 12213 4810 12234 4824 12244 4809 12238
      4809 12252 4832 12240 4845 12257 4829 12251
      4823 12273 4809 12256 4811 12259 4816 12269
      4808 12288 4842 12265 4842 12289 4852 12293
      4858 12264 4846 12250 4858 12261 4865 12233
TIME...MOT...LOC 0856Z 260DEG 47KT 4847 12188 

$$

PULLIN

The office that day

Everything else NWS Seattle, WA issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jan 12, 4:32 PM PSTRiver Flood WarningSEWThurston43 hr
Jan 12, 4:32 PM PSTRiver Flood WarningSEWLewis39 hr
Jan 12, 8:02 PM PSTWind AdvisorySEWSan Juan10 hr
Jan 12, 9:08 PM PSTSmall Craft AdvisorySEW6 days
Jan 12, 11:14 PM PSTRiver Flood WarningSEWGrays Harbor12 hr
Jan 13, 12:27 AM PSTSpecial Marine WarningSEW33 min
Jan 13, 1:09 AM PSTSpecial Weather StatementSEWSnohomish51 min
Jan 13, 1:57 AM PSTRiver Flood WarningSEWLewis18 hr
Jan 13, 1:57 AM PSTRiver Flood WarningSEWLewis17 hr
Jan 13, 4:50 AM PSTRiver Flood WarningSEWSnohomish9 hr
Jan 13, 4:50 AM PSTRiver Flood WarningSEWSnohomish12 hr
Jan 13, 5:03 AM PSTRiver Flood WarningSEWSnohomish19 hr
Jan 13, 6:27 AM PSTRiver Flood WarningSEWKing, Pierce41 hr
Jan 13, 6:27 AM PSTRiver Flood WarningSEWSnohomish22 hr
Jan 13, 8:32 AM PSTGale WarningSEW3 hr
Jan 13, 8:32 AM PSTSmall Craft AdvisorySEW5 hr
Jan 13, 12:31 PM PSTRiver Flood WarningSEWGrays Harbor12 hr

Nearby

Severe Thunderstorm Warnings in Washington, 2021Every severe thunderstorm 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.