Alert archive / Colorado / Special Weather Statements in 2011

Special Weather Statement, NWS Denver/Boulder, CO

July 2, 2011Jefferson County, Colorado

NWS Denver/Boulder, CO issued this special weather statement at Jul 2, 2011, 2:14 PM MDT for Jefferson County, Colorado. It was in force for 31 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
Jul 2, 2011, 2:14 PM MDT (20:14 UTC)
Expired
Jul 2, 2011, 2:45 PM MDT
In force
31 min
Issued by
NWS Denver/Boulder, CO

County Jefferson County, CO

The radar

The Denver radar (KFTG), 54 km from the middle of the area, began a volume at 20:17 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

Denver, CO (KDNR), launched 12:00Z, 8.2 hours before the alert went out and 164 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, Denver, CO at 12:00Z on 2011-07-02Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1031 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, Denver, CO at 12:00Z on 2011-07-02The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 10 square meters per square second.193958Sfc1 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
1031 J/kg
Mixed-layer CIN
-97 J/kg
Mixed-layer LCL
1074 m above ground
0-6 km bulk shear
18 kt
0-1 km storm-relative helicity
10 m²/s²
0-3 km storm-relative helicity
96 m²/s²
Significant tornado parameter
0.0
Supercell composite
4.9

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

<!doctype html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title>Service Notice</title>
  <link rel="stylesheet" href="index.css">
</head>
<body>
  <main class="wrap">
    <section class="card" role="status" aria-live="polite">
      <div class="status" id="status">Temporary Notice</div>
      <h1 id="headline">This service is currently unavailable.</h1>
      <p id="message1">
        The site you requested is temporarily down for maintenance or an unexpected outage.
      </p>
      <p id="message2">
        Please try again in a few minutes.
      </p>
      <p class="small" id="detail">
        If you are an administrator, restore upstream service and remove the redirect/fallback rule when normal operations resume.
      </p>
    </section>
  </main>
  <script src="index.js"></script>
</body>
</html>

What forecasters said that day

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

NWS Denver/Boulder, CO wrote its last area forecast discussion before this special weather statement went out at Jul 2, 3:13 AM MDT, 11 hours 1 minute earlier.

Area forecast discussion, Jul 2, 3:13 AM MDT, 11 hours 1 minute before
<!doctype html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title>Service Notice</title>
  <link rel="stylesheet" href="index.css">
</head>
<body>
  <main class="wrap">
    <section class="card" role="status" aria-live="polite">
      <div class="status" id="status">Temporary Notice</div>
      <h1 id="headline">This service is currently unavailable.</h1>
      <p id="message1">
        The site you requested is temporarily down for maintenance or an unexpected outage.
      </p>
      <p id="message2">
        Please try again in a few minutes.
      </p>
      <p class="small" id="detail">
        If you are an administrator, restore upstream service and remove the redirect/fallback rule when normal operations resume.
      </p>
    </section>
  </main>
  <script src="index.js"></script>
</body>
</html>
Hazardous weather outlook, Jul 2, 12:03 PM MDT, 2 hours 11 minutes before
HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE DENVER CO
1203 PM MDT SAT JUL 02 2011

COZ030>051-031200-
JACKSON COUNTY BELOW 9000 FEET-WEST JACKSON AND WEST GRAND
COUNTIES ABOVE 9000 FEET-GRAND AND SUMMIT COUNTIES BELOW 9000
FEET-SOUTH AND EAST JACKSON/LARIMER/NORTH AND NORTHEAST GRAND/
NORTHWEST BOULDER COUNTIES ABOVE 9000 FEET-SOUTH AND SOUTHEAST
GRAND/WEST CENTRAL AND SOUTHWEST BOULDER/GILPIN/CLEAR CREEK/
SUMMIT/NORTH AND WEST PARK COUNTIES ABOVE 9000 FEET-LARIMER AND
BOULDER COUNTIES BETWEEN 6000 AND 9000 FEET-JEFFERSON AND WEST
DOUGLAS COUNTIES ABOVE 6000 FEET/GILPIN/CLEAR CREEK/NORTHEAST PARK
COUNTIES BELOW 9000 FEET-CENTRAL AND SOUTHEAST PARK COUNTY-LARIMER
COUNTY BELOW 6000 FEET/NORTHWEST WELD COUNTY-BOULDER AND JEFFERSON
COUNTIES BELOW 6000 FEET/WEST BROOMFIELD COUNTY-NORTH DOUGLAS
COUNTY BELOW 6000 FEET/DENVER/WEST ADAMS AND ARAPAHOE COUNTIES/
EAST BROOMFIELD COUNTY-ELBERT/CENTRAL AND EAST DOUGLAS COUNTIES
ABOVE 6000 FEET-NORTHEAST WELD COUNTY-CENTRAL AND SOUTH WELD
COUNTY-MORGAN COUNTY-CENTRAL AND EAST ADAMS AND ARAPAHOE COUNTIES-
NORTH AND NORTHEAST ELBERT COUNTY BELOW 6000 FEET/NORTH LINCOLN
COUNTY-SOUTHEAST ELBERT COUNTY BELOW 6000 FEET/SOUTH LINCOLN
COUNTY-LOGAN COUNTY-WASHINGTON COUNTY-SEDGWICK COUNTY-PHILLIPS
COUNTY-
1203 PM MDT SAT JUL 02 2011

THIS HAZARDOUS WEATHER OUTLOOK IS FOR NORTHEAST AND NORTH CENTRAL
COLORADO.

...SLIGHT RISK OF SEVERE THUNDERSTORMS IN NORTHEAST COLORADO THIS
AFTERNOON AND EVENING...

.DAY ONE...TODAY AND TONIGHT

SCATTERED THUNDERSTORMS SHOULD BEGIN FORMING OVER AND NEAR THE FRONT
RANGE ANY TIME AFTER 1 PM TODAY. STORMS ROUGHLY SOUTH OF THE BOULDER
AND LARIMER COUNTY LINE ARE EXPECTED TO TRACK SOUTHEAST OVER
SOUTHERN PORTIONS OF THE I-25 URBAN CORRIDOR INCLUDING THE GREATER
DENVER METRO AREA BETWEEN 1 AND 6 PM THIS AFTERNOON. HAIL UP TO
THREE-QUARTER INCH IN DIAMETER...BRIEF HEAVY RAIN AND WIND GUSTS TO
50 MPH ARE POSSIBLE WITH THESE STORMS.

A SECOND WAVE OF THUNDERSTORMS IS EXPECTED TO FORM OVER THE NORTHERN
FOOTHILLS UP ALONG THE WYOMING BORDER AFTER 3 PM WITH PASSAGE OF A
WEAK UPPER LEVEL WEATHER DISTURBANCE. THESE STORMS WILL HAVE THE
POTENTIAL TO BECOME SEVERE...POSSIBLY PRODUCING HAIL UP TO 1.5
INCHES IN DIAMETER...WIND GUSTS IN EXCESS OF 60 MPH...AND HEAVY
RAINFALL. THESE STORMS MAY EVEN GENERATE A TORNADO OR TWO AS TRACK
THE ACROSS THE NORTHEAST CORNER OF THE STATE WHERE THE GREATEST
MOISTURE...INSTABILITY AND VERTICAL SHEAR WILL EXIST.

THUNDERSTORMS SHOULD END BY 8 PM THIS EVENING...EXCEPT THOSE IN THE
NORTHEAST CORNER WHERE THEY COULD LINGER BEYOND MIDNIGHT.

.DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY

SUNDAY LOOKS HOT AND DRY ACROSS THE FORECAST AREA.  MONDAY IS HOT
AGAIN...BUT WITH A SLIGHT CHANCE OF LATE DAY SHOWERS AND
THUNDERSTORMS.  FOR TUESDAY THROUGH FRIDAY...MORE MOISTURE IS
EXPECTED WITH A CHANCE OF AFTERNOON AND EVENING SHOWERS AND
THUNDERSTORMS FOR MOST AREAS.  TEMPERATURES WILL COOL OFF SOME
TUESDAY  THROUGH FRIDAY.

SPOTTER ACTIVATION MAY BE NECESSARY ALONG THE FRONT RANGE BY 2 PM
TODAY.

BAKER/RJK

In the hours before

Special weather statement, Jul 2, 2:14 PM MDT, 0 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE DENVER CO
214 PM MDT SAT JUL 2 2011

COZ036-039-040-022045-
JEFFERSON AND WEST DOUGLAS COUNTIES ABOVE 6000 FEET/GILPIN/CLEAR
CREEK/NORTHEAST PARK COUNTIES BELOW 9000 FEET CO-
NORTH DOUGLAS COUNTY BELOW 6000 FEET/DENVER/WEST ADAMS AND ARAPAHOE
COUNTIES/EAST BROOMFIELD COUNTY CO-
BOULDER AND JEFFERSON COUNTIES BELOW 6000 FEET/WEST BROOMFIELD
COUNTY CO-
214 PM MDT SAT JUL 2 2011

THE NATIONAL WEATHER SERVICE IN DENVER HAS ISSUED A SIGNIFICANT
WEATHER ADVISORY FOR

  CENTRAL JEFFERSON COUNTY
  NORTH CENTRAL DOUGLAS COUNTY
  EXTREME SOUTHWESTERN ARAPAHOE COUNTY
  EXTREME SOUTHWESTERN DENVER COUNTY

AT 214 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
THUNDERSTORM CAPABLE OF PRODUCING PENNY SIZE HAIL.  THIS STORM WAS
LOCATED 5 MILES EAST OF ASPEN PARK...OR 18 MILES SOUTHWEST OF
DENVER...MOVING EAST AT 15 MPH.

LOCATIONS IN THE ADVISORY INCLUDE BUT ARE NOT LIMITED TO TINY TOWN...
SHERIDAN...ROXBOROUGH PARK...MORRISON...LOUVIERS...INDIAN HILLS...
CONIFER...CHATFIELD RESERVOIR...ASPEN PARK...LITTLETON...SOUTHERN
LAKEWOOD...SOUTHERN ENGLEWOOD AND SOUTHWESTERN DENVER.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

THIS STORM WILL PRODUCE DANGEROUS CLOUD-TO-GROUND LIGHTNING. IF
OUTDOORS...STAY AWAY FROM ISOLATED HIGH OBJECTS SUCH AS TREES AND
MOVE INDOORS IF POSSIBLE. WHEN INDOORS...STAY AWAY FROM WINDOWS AND
DOORS AND AVOID USING LAND LINE TELEPHONES UNLESS IT IS AN EMERGENCY.
TRY TO UNPLUG UNNECESSARY ELECTRICAL APPLIANCES BEFORE THE
THUNDERSTORM APPROACHES. REMEMBER...IF YOU CAN HEAR THUNDER...YOU ARE
IN DANGER OF BEING STRUCK BY LIGHTNING.

&&

LAT...LON 3966 10497 3944 10500 3943 10531 3965 10530
TIME...MOT...LOC 2014Z 263DEG 13KT 3954 10518

The office that day

Everything else NWS Denver/Boulder, CO issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jul 2, 12:17 AM MDTSevere Thunderstorm WarningBOULarimer43 min
Jul 2, 1:23 AM MDTSevere Thunderstorm WarningBOULincoln, Washington52 min
Jul 2, 12:16 PM MDTAreal Flood AdvisoryBOUJackson71 hr
Jul 2, 3:18 PM MDTSpecial Weather StatementBOUDouglas27 min
Jul 2, 3:46 PM MDTSpecial Weather StatementBOULogan29 min
Jul 2, 3:52 PM MDTSevere Thunderstorm WarningBOULogan38 min
Jul 2, 3:54 PM MDTSpecial Weather StatementBOUElbert36 min
Jul 2, 4:22 PM MDTSpecial Weather StatementBOUMorgan23 min
Jul 2, 4:27 PM MDTSpecial Weather StatementBOUAdams33 min
Jul 2, 4:45 PM MDTSevere Thunderstorm WarningBOUAdams30 min
Jul 2, 5:05 PM MDTTornado WarningBOUWashington25 min
Jul 2, 5:16 PM MDTSevere Thunderstorm WarningBOUAdams, Morgan, Washington59 min
Jul 2, 5:31 PM MDTSevere Thunderstorm WarningBOUWashington44 min
Jul 2, 5:44 PM MDTTornado WarningBOUWashington31 min
Jul 2, 5:49 PM MDTSpecial Weather StatementBOULincoln26 min
Jul 2, 5:58 PM MDTSevere Thunderstorm WarningBOUElbert, Lincoln62 min

Nearby

Special Weather Statements in Colorado, 2011Every special weather statement in 2011

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.