Alert archive / Colorado / Severe Thunderstorm Warnings in 2009

Severe Thunderstorm Warning 237, NWS Denver/Boulder, CO

August 10, 2009Lincoln County, Colorado

NWS Denver/Boulder, CO issued this severe thunderstorm warning at Aug 10, 2009, 8:45 PM MDT for Lincoln County, Colorado. It was in force for 45 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
Aug 10, 2009, 8:45 PM MDT (02:45 UTC)
Expired
Aug 10, 2009, 9:30 PM MDT
In force
45 min
Issued by
NWS Denver/Boulder, CO
Area
Storm-based polygon

County Lincoln County, CO

The radar

The Pueblo radar (KPUX), 82 km from the middle of the area, began a volume at 02:49 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.

IssuedProductOfficeLasted
Aug 10, 4:43 PM MDTSevere Thunderstorm WatchSPC9 hr

The nearest sounding before it

Denver, CO (KDNR), launched 00:00Z, 2.8 hours before the alert went out and 101 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 00:00Z on 2009-08-11Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 128 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 00:00Z on 2009-08-11The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -26 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
128 J/kg
Mixed-layer CIN
-24 J/kg
Mixed-layer LCL
2968 m above ground
0-6 km bulk shear
45 kt
0-1 km storm-relative helicity
-26 m²/s²
0-3 km storm-relative helicity
98 m²/s²
Significant tornado parameter
0.0
Supercell composite
-0.1

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 Aug 10, 3:15 PM MDT, 5 hours 30 minutes earlier.

Area forecast discussion, Aug 10, 3:15 PM MDT, 5 hours 30 minutes before
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DENVER CO
315 PM MDT MON AUG 10 2009

.SHORT TERM...MODERATE WESTERLY FLOW ALOFT CONTINUES OVER THE STATE
WITH LITTLE IN THE WAY OF DISCERNABLE SHORT WAVE ACTIVITY AT THIS
TIME.  WEAK HIGH PRESSURE REMAINS OVER NORTHEAST COLORADO PRODUCING
WEAK SOUTHEASTERLY FLOW ALCROSS THE PLAINS.  AS THIS WEAK EASTERLY
COMPONENT CONTINUES...LOW LEVEL MOISTURE WILL BE HELD OVER THE
REGION...ALLOWING FOR DAYTIME HEATING TO DE-STABIIZE THE AIRMASS
LATER IN THE DAY.  THE LAST FEW EVENINGS HAVE FEATURED
LATE-INITIATING CONVECTION AND TONIGHT MAY NOT BE ANY DIFFERENT.
THE ENTRANCE REGION OF AN UPPER LEVEL JET WILL BE POSITIONED OVER
THE NORTHEAST CORNER OF THE STATE...WHICH HAS BEEN A KEY INGREDIENT
WITH NOCTURNAL CONVECTION ON SEVERAL OCCASIONS IN THE PAST COUPLE
WEEKS.  GIVEN SOME WEAK CONVECTION ALREADY DEVELOPING OVER THE
FOOTHILLS AT THIS TIME...WILL LET 20-30 PERCENT POPS CONTINUE ACROSS
THE PLAINS THROUGH THIS EVENING.  MODEL SOUNDINGS SHOWED 1500-2000
J/KG OF CAPE FOR LATE THIS AFTERNOON AND EVENING.  RECENT
PLATTEVILLE PROFILER DATA SHOWS INCREASING EASTERLY FLOW UP TO 700
MB WITH MODEST WESTERLY FLOW CONTINUING ALOFT.  THE ENTIRE GAMUT OF
SEVERE WEATHER WILL BE POSSIBLE WITH STORMS IF THEY INITIATE.  HEAVY
RAIN...LARGE HAIL AND STRONG WINDS WILL BE POSSIBLE.  SOIL
CONDITIONS IN WELD...EASTERN ADAMS AND ARAPAHOE AND SOUTHERN
WASHINGTON COUNTIES WILL NEED TO BE WATCHED...BASED ON HEAVY RAINS
THAT HAVE FALLEN THE PAST COUPLE NIGHTS.

FOR TUESDAY...THINGS MAY JUST RESET FOR ANOTHER ROUND OF SHOWERS
TOMORROW EVENING.  SOUTHEASTERLY LOW LEVEL FLOW MAY ACTUALLY BE A
LITTLE MORE ORGANIZED...HELPING TO KEEP LOW LEVEL MOISTURE IN PLACE
OVER THE REGION.  RISING HEIGHTS MAY CAUSE FOR WEAKER WINDS
ALOFT...MAKING HEAVY RAINING STORMS A LARGER POSSIBILITY.  IT IS
AFTER ALL THE HEAVY RAIN SEASON IN COLORADO...AND MOISTURE HAS BEEN
IN PLACE FOR A FEW DAYS NOW.

.LONG TERM...POSITIVE TILT UPPER LEVEL RIDGE BREAKS OVER THE CENTRAL
ROCKY MTN REGION ON WEDNESDAY ON ITS WAY EAST ACROSS THE NORTHERN
GREAT PLAINS LATE IN THE WEEK. WITH ITS PASSAGE TEMPERATURE ALOFT
WARM AND SO DO TEMPS AT GROUND LEVEL. MODEL SOUNDINGS AND CROSS
SECTIONS ALSO REVEALS GRADUAL DRYING WITH THE LOWEST RHS PROGGED FOR
THE MTNS AND HIGH MTN VALLEYS. ALTHOUGH ON THE PLAINS...A PERSISTENT
SLY LOW-LEVEL FLOW WILL SLOW THIS DRYING AND KEEP LATE BOUNDARY
LAYER INSTABILITY ON THE HIGH SIDE. PREVIOUS FORECAST INDICATE A
SLIGHT CHANGE OF AFTERNOON AND EVENING T-STORMS THROUGH FRIDAY.
CAN/T ARGUE WITH THAT...HOWEVER STORM CHANCES APPEAR EVEN LOWER IF
NOT CLOSE TO ZERO ON THURSDAY AND FRIDAY WITH LIGHT W-SWLY/DOWNSLOPE
FLOW SCOURING OUT LOW-LEVEL MOISTURE ALONG THE FRONT RANGE. WHILE
SLY FLOW OUT ALONG THE EASTERN BORDER ARE FCST TO KEEP DEWPTS UP IN
THE 50-60F RANGE.

BY THE WEEKEND...WITH THE UPPER RIDGE WELL TO OUR EAST FLOW ALOFT
TURNS SWLY AS A SHARP SHORTWAVE TROUGH CARVES OUT OVER THE PACIFIC
NORTHWEST. MEDIUM RANGE MODELS HAVE COME INTO BETTER AGREEMENT THE
LAST TWO RUNS REGARDING THIS FEATURE. AS THIS TROUGH MOVES CLOSER
MODELS SHOW SUBTROPICAL MOISTURE ADVECTING NWRD UP ALONG THE SPINE
OF THE ROCKIES AND OVER COLORADO BY LATE ON SATURDAY. TEMPS ALOFT
ALSO BEGIN COOLING WHICH MOS GUIDANCE REFLECTS IN LOWER MAX
TEMPERATURES. INCREASED CLOUD COVER PROBABLY ANOTHER REASON FOR THE
COOL DOWN OVER THE WEEKEND. FOR NOW WILL REFRAIN FROM GOING AS WET
OR AS COOL AS THE MODELS INDICATE. HOWEVER SHOULD THIS POTENT TROUGH
DIG AND MIGRATE THE WAY THIS LATEST RUN OF THE MODELS INDICATE...
LATER FORECAST ISSUANCES MAY DEPICT COOLER AND WETTER CONDITIONS...
AT LEAST BY SUNDAY AND MONDAY.

&&

.AVIATION...EVENING THUNDERSTORMS WILL BE A THREAT THROUGH AS LATE
AS 05Z.  IF STORMS DEVELOP...THEIR MOTION SHOULD PRIMARILY BE
EASTWARD AT 10-15 MPH.  HEAVY RAINS...LARGE HAIL AND STRONG WINDS
WILL BE POSSIBLE FROM STORMS THAT DEVELOP.  VFR CONDS SHOULD PREVAIL
EXCEPT FOR THUNDERSTORMS PRODUCING SOME MVFR CIGS/VSBYS.

&&

.BOU WATCHES/WARNINGS/ADVISORIES...NONE.

KDRBY/BAKER
Hazardous weather outlook, Aug 10, 10:59 AM MDT, 9 hours 46 minutes before
HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE DENVER CO
1059 AM MDT MON AUG 10 2009

COZ030>051-111200-
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-
1059 AM MDT MON AUG 10 2009

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

.DAY ONE...TODAY AND TONIGHT

SCATTERED THUNDERSTORMS ARE EXPECTED TO DEVELOP AFTER 3 PM WITH A
FEW STORMS BECOMING SEVERE OVER THE PLAINS OF NORTHEAST COLORADO
THROUGH THE EVENING.  HAIL UP TO 1.75 INCHES IN DIAMETER...WINDS UP
TO 60 MPH AND VERY HEAVY RAIN WILL BE POSSIBLE.  AN ISOLATED TORNADO
COULD ALSO OCCUR.  THE AIRMASS OVER NORTHEAST COLORADO REMAINS MOIST
THIS MORNING WITH LIGHT SOUTHEASTERLY WINDS EXPECTED TO KEEP THE
MOISTURE IN THE REGION.  DAYTIME HEATING WILL DE-STABILIZE THE
ATMOSPHERE DURING THE AFTERNOON HOURS AND STRONGER WINDS ALOFT THIS
EVENING WILL HELP DEVELOPING THUNDERSTORMS TO MAINTAIN THEIR
STRENGTH.  IF THUNDERSTORMS WITH HEAVY RAIN DEVELOP OVER LOCATIONS
THAT HAVE EXPERIENCED HEAVY RAINFALL IN THE PAST COUPLE EVENINGS...
FLOODING PROBLEMS MAY DEVELOP.  CENTRAL AND NORTHERN WELD COUNTY...
EASTERN ARAPAHOE AND ADAMS AND SOUTHERN WASHINGTON COUNTIES ARE AT
THE HIGHEST RISK OF FLOODING PROBLEMS.

.DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY

THERE WILL BE A CHANCE OF THUNDERSTORMS GENERALLY EAST OF THE
MOUNTAINS EACH AFTERNOON AND EVENING THROUGH SUNDAY.  LATE DAY
STORMS...MAINLY EAST OF THE I-25 URBAN CORRIDOR...MAY PRODUCE LARGE
HAIL...HEAVY RAINFALL AND STRONG GUSTY WINDS.  A FEW OF THESE STORMS
MAY LINGER WELL BEYOND MIDNIGHT.  STRONG DAYTIME HEATING COUPLED
WITH THE ADDITIONAL LIFT GENERATED BY PASSING WEAK UPPER LEVEL
DISTURBANCES WILL PRODUCE THE DAILY CYCLE OF THUNDERSTORMS.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION MAY BE NEEDED AFTER 3 PM.

DANKERS/BAKER

In the hours before

Special weather statement, Aug 10, 4:24 PM MDT, 4 hours 21 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE DENVER CO
424 PM MDT MON AUG 10 2009

COZ041-046-102300-
NORTH AND NORTHEAST ELBERT COUNTY BELOW 6000 FEET/NORTH LINCOLN
COUNTY CO-ELBERT/CENTRAL AND EAST DOUGLAS COUNTIES ABOVE 6000 FEET
CO-
424 PM MDT MON AUG 10 2009

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

  WEST CENTRAL ELBERT COUNTY
  EAST CENTRAL DOUGLAS COUNTY

AT 425 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
THUNDERSTORM CAPABLE OF PRODUCING PENNY SIZE HAIL.  THIS STORM WAS
LOCATED 2 MILES NORTHWEST OF PONDEROSA PARK...OR 27 MILES SOUTHEAST
OF DENVER...MOVING EAST AT 10 MPH.

LOCATIONS IN THE ADVISORY INCLUDE BUT ARE NOT LIMITED TO THE
PINERY...PONDEROSA PARK...KIOWA AND ELIZABETH.

LAT...LON 3954 10436 3929 10435 3932 10475 3950 10475
TIME...MOT...LOC 2225Z 267DEG 10KT 3942 10465
Special weather statement, Aug 10, 5:25 PM MDT, 3 hours 20 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE DENVER CO
525 PM MDT MON AUG 10 2009

COZ040-041-110000-
NORTH DOUGLAS COUNTY BELOW 6000 FEET/DENVER/WEST ADAMS AND ARAPAHOE
COUNTIES/EAST BROOMFIELD COUNTY CO-
ELBERT/CENTRAL AND EAST DOUGLAS COUNTIES ABOVE 6000 FEET CO-
525 PM MDT MON AUG 10 2009

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

  NORTHWESTERN ELBERT COUNTY
  NORTHEASTERN DOUGLAS COUNTY
  SOUTHWESTERN ARAPAHOE COUNTY

AT 526 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
THUNDERSTORM CAPABLE OF PRODUCING PENNY SIZE HAIL.  THIS STORM WAS
LOCATED 3 MILES NORTHWEST OF PARKER...OR 16 MILES SOUTHEAST OF
DENVER...MOVING EAST AT 15 MPH.

LOCATIONS IN THE ADVISORY INCLUDE BUT ARE NOT LIMITED TO SURREY
RIDGE...PARKER...BEVERLY HILLS...CENTENNIAL AND SOUTHERN AURORA.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL MIDNIGHT MDT
TUESDAY MORNING FOR NORTHEASTERN COLORADO.

&&

LAT...LON 3965 10461 3950 10453 3947 10488 3960 10493
TIME...MOT...LOC 2326Z 260DEG 13KT 3953 10481
Special weather statement, Aug 10, 5:30 PM MDT, 3 hours 15 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE DENVER CO
530 PM MDT MON AUG 10 2009

COZ041-046-110000-
NORTH AND NORTHEAST ELBERT COUNTY BELOW 6000 FEET/NORTH LINCOLN
COUNTY CO-ELBERT/CENTRAL AND EAST DOUGLAS COUNTIES ABOVE 6000 FEET
CO-
530 PM MDT MON AUG 10 2009

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

  CENTRAL ELBERT COUNTY

AT 530 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
THUNDERSTORM CAPABLE OF PRODUCING PENNY SIZE HAIL.  THIS STORM WAS
LOCATED 3 MILES NORTHEAST OF KIOWA...OR 36 MILES SOUTHEAST OF
DENVER...MOVING EAST AT 15 MPH.

LOCATIONS IN THE ADVISORY INCLUDE BUT ARE NOT LIMITED TO KIOWA.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL MIDNIGHT MDT
TUESDAY MORNING FOR NORTHEASTERN COLORADO.

&&

LAT...LON 3948 10410 3925 10409 3927 10451 3947 10451
TIME...MOT...LOC 2330Z 269DEG 15KT 3939 10432
Special weather statement, Aug 10, 5:33 PM MDT, 3 hours 12 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE DENVER CO
533 PM MDT MON AUG 10 2009

COZ038-042-048-110030-
LOGAN COUNTY CO-NORTHEAST WELD COUNTY CO-
LARIMER COUNTY BELOW 6000 FEET/NORTHWEST WELD COUNTY CO-
533 PM MDT MON AUG 10 2009

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

  WESTERN LOGAN COUNTY
  NORTHEASTERN WELD COUNTY

AT 531 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
THUNDERSTORM CAPABLE OF PRODUCING PENNY SIZE HAIL.  THIS STORM WAS
LOCATED 5 MILES NORTHWEST OF KEOTA...OR 38 MILES NORTHWEST OF FORT
MORGAN.  ANOTHER STORM OVER KIMBALL NEBRASKA WILL BE MOVING INTO THE
AREA AS WELL.  THE STORMS WERE MOVING SOUTHEAST AT 20 MPH.

LOCATIONS IN THE ADVISORY INCLUDE BUT ARE NOT LIMITED TO WILLARD...
WESTPLAINS...STONEHAM...PEETZ...PAWNEE PASS...PAWNEE BUTTES...
PADRONI...NORTH STERLING RESERVOIR...NEW RAYMER...LOGAN CORNERS...
KEOTA...HEREFORD...GROVER...BRIGGSDALE...ATWOOD AND STERLING.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL MIDNIGHT MDT
TUESDAY MORNING FOR NORTHEASTERN COLORADO.

&&

LAT...LON 4100 10310 4053 10318 4055 10443 4097 10438
TIME...MOT...LOC 2331Z 290DEG 53KT 4074 10411
Local storm report, Aug 10, 8:03 PM MDT, 42 minutes before
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The office that day

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

IssuedProductOfficeCountiesLasted
Aug 10, 6:04 PM MDTSevere Thunderstorm WarningBOULogan, Weld37 min
Aug 10, 6:57 PM MDTSevere Thunderstorm WarningBOULincoln26 min
Aug 10, 7:27 PM MDTSevere Thunderstorm WarningBOUElbert, Lincoln63 min
Aug 10, 7:56 PM MDTSevere Thunderstorm WarningBOUWashington42 min
Aug 10, 8:11 PM MDTSevere Thunderstorm WarningBOUWashington26 min

Nearby

Severe Thunderstorm Warnings in Colorado, 2009Every 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.