Alert archive / Colorado / Severe Thunderstorm Warnings in 2009

Severe Thunderstorm Warning 156, NWS Denver/Boulder, CO

July 17, 2009Phillips County, Colorado

NWS Denver/Boulder, CO issued this severe thunderstorm warning at Jul 17, 2009, 6:15 PM MDT for Phillips County, Colorado. It was in force for 34 min. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued: Jul 17, 2009, 6:15 PM MDT (00:15 UTC)
Expired: Jul 17, 2009, 6:49 PM MDT
In force: 34 min
Issued by: NWS Denver/Boulder, CO
Area: Storm-based polygon

County Phillips County, CO

The radar

The Goodland radar (KGLD), 148 km from the middle of the area, began a volume at 00:17 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 watch it was issued in

The SPC watch in force over the same counties when this warning went out.

Issued	Product	Office	Lasted
Jul 17, 12:59 PM MDT	Tornado Watch	SPC	6 hr

The nearest sounding before it

Denver, CO (KDNR), launched 00:00Z, 0.3 hours before the alert went out and 109 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 3559 m above ground
0-6 km bulk shear: 48 kt
0-1 km storm-relative helicity: 25 m²/s²
0-3 km storm-relative helicity: 179 m²/s²
Significant tornado parameter: 0.0
Supercell composite: -0.0

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this severe thunderstorm warning 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 severe thunderstorm warning went out at Jul 17, 1:58 PM MDT, 4 hours 17 minutes earlier.

Area forecast discussion, Jul 17, 1:58 PM MDT, 4 hours 17 minutes before

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Hazardous weather outlook, Jul 17, 11:13 AM MDT, 7 hours 2 minutes before

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE DENVER CO
1113 AM MDT FRI JUL 17 2009

COZ030>051-181200-
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-
1113 AM MDT FRI JUL 17 2009

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

.DAY ONE...TODAY AND TONIGHT

THERE WILL BE A CHANCE OF THUNDERSTORMS OVER THE PLAINS THIS
AFTERNOON AND EVENING WITH A SLIGHT CHANCE OF THUNDERSTORMS IN AND
NEAR THE FOOTHILLS.  A FEW STORMS COULD BE SEVERE OVER THE PLAINS
WITH HAIL TO ONE INCH IN DIAMETER ALONG WITH WIND GUSTS TO 60 MPH.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY

THERE WILL BE A CHANCE FOR AFTERNOON AND EVENING THUNDERSTORMS OVER
THE PALMER DIVIDE AND NEARBY AREAS ON SATURDAY...WITH A LESSER
CHANCE ELSEWHERE. SUNDAY THROUGH THE MIDDLE OF NEXT WEEK...THE BEST
CHANCE FOR LATE DAY THUNDERSTORMS...ALBEIT A SMALL ONE...WILL SHIFT
TO THE FRONT RANGE FOOTHILLS AND SOUTH PARK AS WELL AS OVER THE
PALMER DIVIDE. THE LIKELIHOOD FOR SEVERE WEATHER SHOULD REMAIN LOW
AS MUCH OF THE AREA WILL REMAIN UNDER THE INFLUENCE OF A STRONG AND
VERY WARM UPPER LEVEL HIGH PRESSURE RIDGE.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION WILL NOT BE NEEDED TODAY OR TONIGHT.

MEIER/BAKER

In the hours before

Special weather statement, Jul 17, 2:37 PM MDT, 3 hours 38 minutes before

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE DENVER CO
237 PM MDT FRI JUL 17 2009

...TORNADO WATCH IN EFFECT FOR NORTHEAST COLORADO...

A TORNADO WATCH IS IN EFFECT FOR MUCH OF NORTHEAST COLORADO THROUGH
7 PM THIS EVENING INCLUDING ADAMS AND ARAPAHOE COUNTIES.  THE THREAT
OF SEVERE WEATHER IS MUCH GREATER TO THE EAST OF METRO DENVER IN THE
EASTERN HALF OF ADAMS AND ARAPAHOE COUNTIES.  THE TORNADO WATCH DOES
NOT INCLUDE DENVER COUNTY OR DENVER INTERNATIONAL AIRPORT.

RTG

Special weather statement, Jul 17, 5:00 PM MDT, 1 hour 15 minutes before

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Special weather statement, Jul 17, 5:35 PM MDT, 40 minutes before

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Local storm report, Jul 17, 6:02 PM MDT, 13 minutes before

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The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 18, 1:51 AM MDT	Special Weather Statement	BOU	Logan	24 min
Jul 18, 2:34 AM MDT	Severe Thunderstorm Warning	BOU	Weld	41 min
Jul 18, 3:16 AM MDT	Severe Thunderstorm Warning	BOU	Logan, Morgan, Weld	24 min
Jul 18, 3:36 AM MDT	Severe Thunderstorm Warning	BOU	Morgan	39 min
Jul 18, 4:07 AM MDT	Severe Thunderstorm Warning	BOU	Morgan, Washington	24 min

Nearby

Severe Thunderstorm Warnings in Colorado, 2009 Every severe thunderstorm warning in 2009

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.