Severe Thunderstorm Warning 82, NWS Denver/Boulder, CO

Issued

Sep 12, 2002, 5:59 PM MDT (23:59 UTC)

Expired

Sep 12, 2002, 7:00 PM MDT

In force

61 min

Issued by

NWS Denver/Boulder, CO

Area

Counties, with a storm outline in the text

County Weld County, CO

The Denver radar (KFTG), 52 km from the middle of the area, began a volume at 00:01 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.

Not verified. The Iowa Environmental Mesonet's Cow found no qualifying storm report inside this severe thunderstorm warning while it was in force. That is not proof nothing happened: reports are thin where few people live.

Cow counts a report within 15 km of the polygon while the warning was in force: a tornado for a tornado warning; hail of 1 inch or more, a gust of 58 mph or more or wind damage for a severe thunderstorm warning; a flash flood report for a flash flood warning.

808 
WUUS55 KBOU 122359
SVRDEN
COC123-130100-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE DENVER CO
558 PM MDT THU SEP 12 2002

THE NATIONAL WEATHER SERVICE IN DENVER HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  SOUTHWESTERN WELD COUNTY IN NORTHEAST COLORADO
  THIS INCLUDES THE CITY OF SOUTHEASTERN GREELEY

* UNTIL 700 PM MDT

* AT 557 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED   
  A SEVERE THUNDERSTORM NEAR HUDSON...OR ABOUT 23 MILES SOUTH OF     
  GREELEY...MOVING EAST AT 20 MPH.

LOCATIONS IN THE WARNING INCLUDE...BUT ARE NOT LIMITED TO...
SOUTHEASTERN GREELEY...EVANS...FORT LUPTON...GILCREST...HUDSON...
JOHNSTOWN...KEENESBURG...KERSEY...LA SALLE...MILLIKEN...MILTON
RESERVOIR...PLATTEVILLE...PROSPECT VALLEY AND ROGGEN.

HAIL...INTENSE RAIN AND LIGHTNING...AND STRONG DAMAGING WINDS ARE 
LIKELY WITH THIS STORM. TAKE COVER IN A SUBSTANTIAL SHELTER UNTIL 
THE STORM PASSES.

SEVERE THUNDERSTORMS PRODUCE DAMAGING WIND IN EXCESS OF 58 MPH...
DESTRUCTIVE HAIL...DEADLY LIGHTNING...AND VERY HEAVY RAIN. FOR YOUR
PROTECTION MOVE TO AN INTERIOR ROOM ON THE LOWEST FLOOR OF YOUR HOME
OR BUSINESS. HEAVY RAINS FLOOD ROADS QUICKLY SO DO NOT DRIVE INTO
AREAS WHERE WATER COVERS THE ROAD.

LAT...LON 4031 10502 4002 10479 4001 10429 4041 10430
          4043 10455
BAKER

NWS Denver/Boulder, CO wrote its last area forecast discussion before this severe thunderstorm warning went out at Sep 12, 2:55 PM MDT, 3 hours 4 minutes earlier.

NORTHEAST AND NORTH CENTRAL COLORADO AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DENVER COLORADO
255 PM MDT THU SEP 12 2002

TONIGHT AND FRIDAY:  CURRENT RADAR PICTURES ARE INDICATING 10-20%
CONVECTIVE COVERAGE RIGHT NOW OVER THE ALPINE AREAS AND ADJACENT
PLAINS.  CROSS SECTIONS AND SATELLITE PICTURES SHOW THE DECENT
MOISTURE TO CONTINUE OVERNIGHT INTO FRIDAY.  FORECAST AND ACARS
SOUNDINGS SHOWS CAPES UNDER 1000 JOULES FOR THE FORECAST AREA INTO
THIS EVENING.  THE LOW LEVEL FLOW IS FAIRLY BENIGN AT THIS TIME
...WITH LITTLE CHANGE EXPECTED THIS EVENING.  THERE IS SOME WEAK
SYNOPTIC SCALE ASCENT IN THE SYNOPTIC SCALE.  OVERALL POP COVERAGE
THIS EVENING WILL BE A BIT LESS THEN YESTERDAY EVENING AND IT WILL
LIKELY END SOONER AS WELL.  GRIDS SHOW THE UPPER TROUGH TO SLIDE
ACROSS THE FORECAST AREA THROUGH THE DAY FRIDAY INTO FRIDAY
EVENING.  DIV-Q GRIDS SHOW WEAK UPWARD FORCING FOR THE FORECAST AREA
UNTIL THE TROUGH AXIS PUSHES ACROSS.  THERE IS CONTINUED MOISTURE ON
FRIDAY FROM THE MODELS BUT A BIT LESS THEN TODAY.  WILL STILL NEED
SOME POPS UNTIL TROUGH AXIS PASSAGE...BUT AGAIN A BIT LESS THEN
TODAY.

FRIDAY NIGHT THROUGH SUNDAY:  CROSS SECTIONS INDICATE MUCH DRIER
CONDITIONS THROUGH THIS PERIOD...WITH WEAK DOWNWARD SYNOPTIC SCALE
FORCING PROGGED FOR SATURDAY NIGHT AND SUNDAY.  IN THE LOW
LEVELS...MODELS SHOW A SURGE OF COOLER AIR AND UPSLOPE INTO THE
FORECAST AREA ABOUT 15Z SATURDAY MORNING.   THE UPSLOPE CONTINUES
INTO SATURDAY EVENING.  HOWEVER IT WILL BE MUCH DRIER...STABLE TOO.
NO POPS.  FOR TEMPERATURES...GRIDS SHOULD READINGS PRETTY STEADY
STATE FOR THE NEXT COUPLE DAYS.  MAYBE A BIT COOLER ON SATURDAY
...THEN A THE WARMEST DAY ON SUNDAY.

IN THE EXTENDED FORECAST...MONDAY THROUGH THURSDAY:  ON MONDAY THE
MODELS SHOW AND UPPER RIDGE HEADING EAST OUT OF THE FORECAST AREA.
BY TUESDAY THE MEDIUM RANGE MODELS SHOW A MEAN TROUGH SETTING UP
OVER THE WESTERN U.S. AND CANADA...BUT ITS MAINLY NORTH THEN WEST
OF US.  THE UPPER FLOW IS FAIRLY ZONAL AND IT STILL DOES NOT LOOK
VERY MOIST.  THE TEMPERATURES STAY AT OF SLIGHTLY ABOVE SEASONAL
NORMALS.  WILL KEEP IT DRY ONE MORE TIME.    RJK

.DEN...NONE.

In the hours before

LOCAL STORM REPORT
NATIONAL WEATHER SERVICE DENVER CO
500 PM MDT THU SEP 12 2002

...PRELIMINARY STORM REPORT FOR SEPTEMBER 12 2002...

TIME(MDT)  .....CITY LOCATION.....STATE   ...EVENT/REMARKS...
           ....COUNTY LOCATION....

0334 PM    3 E CASTLE ROCK           CO   1.00 INCH HAIL
09/12/02   DOUGLAS

0430 PM    3 W ELBERT                CO   1.75 INCH HAIL
09/12/02   ELBERT

0445 PM    3 E ELBERT                CO   2.00 INCH HAIL
09/12/02   ELBERT                         BROKEN SKYLIGHT

JK

Severe Thunderstorm Warnings in Colorado, 2002Every severe thunderstorm warning in 2002

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.