Alert archive / Colorado / Flash Flood Warnings in 1998
Flash Flood Warning 4, NWS Denver/Boulder, CO
NWS Denver/Boulder, CO issued this flash flood warning at Jul 23, 1998, 5:12 PM MDT for Morgan County, Washington County, Colorado. It was in force for 2 hr. No storm report in the archive falls inside the area while it was in force.
The area
The outline the Iowa Environmental Mesonet reconstructed for it; the warning itself named whole counties.
The facts
- Issued
- Jul 23, 1998, 5:12 PM MDT (23:12 UTC)
- Expired
- Jul 23, 1998, 7:15 PM MDT
- In force
- 2 hr
- Issued by
- NWS Denver/Boulder, CO
- Area
- Whole counties; the outline is the Mesonet’s reconstruction
Counties Morgan County, CO, Washington County, CO
The radar
The Denver radar (KFTG), 110 km from the middle of the area, began a volume at 23:16 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, 11.2 hours before the alert went out and 44 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.
- Mixed-layer CAPE
- 81 J/kg
- Mixed-layer CIN
- -228 J/kg
- Mixed-layer LCL
- 1157 m above ground
- 0-6 km bulk shear
- 11 kt
- 0-1 km storm-relative helicity
- 76 m²/s²
- 0-3 km storm-relative helicity
- 85 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
000
TTAA00 KDEN 232318
FFWDEN
COC087-121-240115-
BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE DENVER CO
512 PM MDT THU JUL 23 1998
THE NATIONAL WEATHER SERVICE IN DENVER HAS ISSUED A
* FLASH FLOOD WARNING FOR...
EAST CENTRAL MORGAN COUNTY IN NORTHEAST COLORADO
NORTH CENTRAL WASHINGTON COUNTY IN NORTHEAST COLORADO
* UNTIL 715 PM MDT
* AT 520 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
VERY HEAVY RAIN CONTINUING OVER NORTHWESTERN WASHINGTON AND EASTERN
MORGAN COUNTIES. RADAR ESTIMATES INDICATED 5.0 TO 6.0 INCHES OF
RAIN HAVE FALLEN IN THE PAST 2 HOURS AROUND MESSEX. ANOTHER AREA OF
5.0 TO 6.0 INCHES HAVE FALLEN 5 MILES SOUTH-SOUTHWEST OF MIDWAY.
LOCATIONS IN THE WARNING INCLUDE...HILLROSE...MIDWAY AND PREWITT
RESERVOIR
EXCESSIVE RUNOFF FROM THIS STORM WILL CAUSE FLASH FLOODING OF SMALL
CREEKS AND STREAMS...COUNTRY ROADS...NORMALLY DRY WASHES AND
ARROYOS...AS WELL AS FARMLAND ALONG TH0E BANKS OF CREEKS AND STREAMS.
RJK
LAT...LON 4042 10319 4026 10323 4020 10328 4009 10331
4006 10341 4007 10354 4019 10359 4025 10353
4033 10358 4043 10351What forecasters said that day
The local office's own words before this flash flood warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
In the hours before
Special weather statement, Jul 23, 12:08 PM MDT, 5 hours 4 minutes before
COZ030-032>050-240600- SIGNIFICANT WEATHER OUTLOOK FOR NORTHEAST AND NORTH CENTRAL COLORADO NATIONAL WEATHER SERVICE DENVER CO 1208 PM MDT THU JUL 23 1998 THIS OUTLOOK PERTAINS TO THE FOLLOWING COLORADO COUNTIES ADAMS ARAPAHOE BOULDER CLEAR CREEK DENVER DOUGLAS ELBERT GILPIN GRAND JACKSON JEFFERSON LARIMER LINCOLN LOGAN MORGAN PARK PHILLIPS SEDGWICK SUMMIT WASHINGTON WELD ...FLASH FLOOD WATCH UNTIL MIDNIGHT TONIGHT FOR SOUTHEAST ELBERT AND LINCOLN COUNTIES... SYNOPSIS: THE ATMOSPHERE REMAINS QUITE MOIST AS INDICATED BY HIGHER HUMIDITIES AND THE WIDESPREAD CLOUD COVER. CHANCES FOR RAINFALL LOOK GOOD THIS AFTERNOON AND EVENING ACROSS THE OUTLOOK AREA. HOWEVER A NUMBER OF FACTORS POINT TO NOT AS HEAVY OR AS WIDESPREAD RAINFALL TODAY. FIRST IS A LACK OF FAVORABLE EAST-NORTHEASTERLY UPSLOPE FLOW. SECOND IS THE LACK OF STRONG HEATING DUE TO THE HEAVY CLOUD COVER. AND THIRD IS THE LACK OF AN UPPER LEVEL WEATHER DISTURBANCE OR COLD FRONT TO FOCUS THUNDERSTORM ACTIVITY SUCH WAS THE CASE YESTERDAY. INITIAL SHOWER ACTIVITY EARLY THIS AFTERNOON WILL BE LIGHT AND SCATTERED IN COVERAGE. RAINFALL AMOUNTS WITH THESE SHOWERS WILL BE LESS THAN A QUARTER INCH. BY LATE THIS AFTERNOON THUNDERSTORMS FORMING OVER THE MOUNTAINS ARE EXPECTED TO MOVE SLOWLY NORTHEAST ONTO THE PLAINS. THUNDERSTORMS WILL BE SLOW MOVERS...AGAIN WITH SOME STORMS CAPABLE OF HEAVY RAIN. RAINFALL RATES FROM STORMS MOVING ACROSS THE FRONT RANGE URBAN CORRIDOR SHOULD RANGE FROM A TENTH TO ONE-HALF INCH...WITH SPOTTY RAINFALL RATES UP TO 1.5 INCHES. HEAVIEST RAINFALL SHOULD FALL ACROSS DOUGLAS...SOUTHERN JEFFERSON...ARAPAHOE AND SOUTHERN ELBERT AND SOUTHERN LINCOLN COUNTIES. SOILS IN THESE AREAS ARE ALREADY VERY WET FROM EARLIER RAINFALL. THUS LOCAL FLOODING OF LOW LYING AREAS AND SMALL STREAMS IS POSSIBLE IN THESE COUNTIES AFTER 4 PM MDT. SKYWARN STORM SPOTTERS ARE ASK TO RELAY ANY HEAVY RAIN OR FLOODING REPORTS TO THE NATIONAL WEATHER SERVICE IN DENVER. BAKER
Special weather statement, Jul 23, 12:08 PM MDT, 5 hours 4 minutes before
COZ030-032>050-240600- SIGNIFICANT WEATHER OUTLOOK FOR NORTHEAST AND NORTH CENTRAL COLORADO NATIONAL WEATHER SERVICE DENVER CO 1208 PM MDT THU JUL 23 1998 THIS OUTLOOK PERTAINS TO THE FOLLOWING COLORADO COUNTIES ADAMS ARAPAHOE BOULDER CLEAR CREEK DENVER DOUGLAS ELBERT GILPIN GRAND JACKSON JEFFERSON LARIMER LINCOLN LOGAN MORGAN PARK PHILLIPS SEDGWICK SUMMIT WASHINGTON WELD ...FLASH FLOOD WATCH UNTIL MIDNIGHT TONIGHT FOR SOUTHEAST ELBERT AND LINCOLN COUNTIES... SYNOPSIS: THE ATMOSPHERE REMAINS QUITE MOIST AS INDICATED BY HIGHER HUMIDITIES AND THE WIDESPREAD CLOUD COVER. CHANCES FOR RAINFALL LOOK GOOD THIS AFTERNOON AND EVENING ACROSS THE OUTLOOK AREA. HOWEVER A NUMBER OF FACTORS POINT TO NOT AS HEAVY OR AS WIDESPREAD RAINFALL TODAY. FIRST IS A LACK OF FAVORABLE EAST-NORTHEASTERLY UPSLOPE FLOW. SECOND IS THE LACK OF STRONG HEATING DUE TO THE HEAVY CLOUD COVER. AND THIRD IS THE LACK OF AN UPPER LEVEL WEATHER DISTURBANCE OR COLD FRONT TO FOCUS THUNDERSTORM ACTIVITY SUCH WAS THE CASE YESTERDAY. INITIAL SHOWER ACTIVITY EARLY THIS AFTERNOON WILL BE LIGHT AND SCATTERED IN COVERAGE. RAINFALL AMOUNTS WITH THESE SHOWERS WILL BE LESS THAN A QUARTER INCH. BY LATE THIS AFTERNOON THUNDERSTORMS FORMING OVER THE MOUNTAINS ARE EXPECTED TO MOVE SLOWLY NORTHEAST ONTO THE PLAINS. THUNDERSTORMS WILL BE SLOW MOVERS...AGAIN WITH SOME STORMS CAPABLE OF HEAVY RAIN. RAINFALL RATES FROM STORMS MOVING ACROSS THE FRONT RANGE URBAN CORRIDOR SHOULD RANGE FROM A TENTH TO ONE-HALF INCH...WITH SPOTTY RAINFALL RATES UP TO 1.5 INCHES. HEAVIEST RAINFALL SHOULD FALL ACROSS DOUGLAS...SOUTHERN JEFFERSON...ARAPAHOE AND SOUTHERN ELBERT AND SOUTHERN LINCOLN COUNTIES. SOILS IN THESE AREAS ARE ALREADY VERY WET FROM EARLIER RAINFALL. THUS LOCAL FLOODING OF LOW LYING AREAS AND SMALL STREAMS IS POSSIBLE IN THESE COUNTIES AFTER 4 PM MDT. SKYWARN STORM SPOTTERS ARE ASK TO RELAY ANY HEAVY RAIN OR FLOODING REPORTS TO THE NATIONAL WEATHER SERVICE IN DENVER. BAKER
Special weather statement, Jul 23, 2:57 PM MDT, 2 hours 15 minutes before
COZ067-232130- SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE DENVER CO 257 PM MDT THU JUL 23 1998 ...THUNDERSTORMS INCREASING OVER SOUTHWESTERN DOUGLAS COUNTY... AT 250 PM MDT NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A THUNDERSTORM OVER WESTCREEK...OR ABOUT 27 MILES NORTHWEST OF COLORADO SPRINGS...MOVING EAST AT 10 MILES PER HOUR. THIS STORM WILL PRODUCE VERY HEAVY RAIN UP TO 2 INCHES PER HOUR ALONG WITH DANGEROUS LIGHTNING. PERSONS IN OR NEAR DEVIL'S HEAD...PERRY PARK AND WESTCREEK SHOULD BE ON THE LOOKOUT FOR THREATENING WEATHER AND MOVE TO A PLACE OF SAFETY IF BAD WEATHER APPROACHES. HEAVY RAINS MAY FLOOD LOW LYING AREAS SUCH AS DITCHES AND UNDERPASSES. AVOID T4HESE AREAS AND DO NOT CROSS FLOODED ROADS AS THEY MAY BE WASHED OUT. WATER LEVELS OF SMALL STREAMS AND RIVERS MAY ALSO RISE...THEREFORE SEEK HIGHER GROUND IF THREATENED BY FLOOD WATERS. KLEYLA
Special weather statement, Jul 23, 2:57 PM MDT, 2 hours 15 minutes before
COZ067-232130- SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE DENVER CO 257 PM MDT THU JUL 23 1998 ...THUNDERSTORMS INCREASING OVER SOUTHWESTERN DOUGLAS COUNTY... AT 250 PM MDT NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A THUNDERSTORM OVER WESTCREEK...OR ABOUT 27 MILES NORTHWEST OF COLORADO SPRINGS...MOVING EAST AT 10 MILES PER HOUR. THIS STORM WILL PRODUCE VERY HEAVY RAIN UP TO 2 INCHES PER HOUR ALONG WITH DANGEROUS LIGHTNING. PERSONS IN OR NEAR DEVIL'S HEAD...PERRY PARK AND WESTCREEK SHOULD BE ON THE LOOKOUT FOR THREATENING WEATHER AND MOVE TO A PLACE OF SAFETY IF BAD WEATHER APPROACHES. HEAVY RAINS MAY FLOOD LOW LYING AREAS SUCH AS DITCHES AND UNDERPASSES. AVOID T4HESE AREAS AND DO NOT CROSS FLOODED ROADS AS THEY MAY BE WASHED OUT. WATER LEVELS OF SMALL STREAMS AND RIVERS MAY ALSO RISE...THEREFORE SEEK HIGHER GROUND IF THREATENED BY FLOOD WATERS. KLEYLA
The office that day
Everything else NWS Denver/Boulder, CO issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 23, 4:08 PM MDT | Tornado Warning | BOU | Adams, Arapahoe | 37 min |
| Jul 23, 4:12 PM MDT | Tornado Warning | BOU | Washington | 33 min |
| Jul 23, 4:23 PM MDT | Tornado Warning | BOU | Adams, Arapahoe | 22 min |
| Jul 23, 4:41 PM MDT | Tornado Warning | BOU | Morgan, Washington | 34 min |
| Jul 23, 5:11 PM MDT | Flash Flood Warning | BOU | Adams, Arapahoe | 2 hr |
| Jul 23, 5:47 PM MDT | Tornado Warning | BOU | Washington | 28 min |
Nearby
Flash Flood Warnings in Colorado, 1998Every flash flood warning in 1998
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.