Alert archive / Colorado / Flash Flood Warnings in 1999

Flash Flood Warning 1, NWS Denver/Boulder, CO

May 3, 1999Morgan County, Weld County, Colorado

NWS Denver/Boulder, CO issued this flash flood warning at May 3, 1999, 4:45 AM MDT for Morgan County, Weld County, Colorado. It was in force for 75 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: May 3, 1999, 4:45 AM MDT (10:45 UTC)
Expired: May 3, 1999, 6:00 AM MDT
In force: 75 min
Issued by: NWS Denver/Boulder, CO
Area: Whole counties

Counties Morgan County, CO, Weld County, CO

The radar

The Denver radar (KFTG), 79 km from the middle of the area, began a volume at 10:47 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 00:00Z, 10.8 hours before the alert went out and 95 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: 2616 m above ground
0-6 km bulk shear: 46 kt
0-1 km storm-relative helicity: 32 m²/s²
0-3 km storm-relative helicity: 183 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

The text of this product is not in the archive. The NWS text archive before 2002 is incomplete.

What 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.

NWS Denver/Boulder, CO wrote its last area forecast discussion before this flash flood warning went out at May 3, 3:45 AM MDT, 1 hour earlier.

Area forecast discussion, May 3, 3:45 AM MDT, 1 hour before

NORTHEAST AND NORTH CENTRAL COLORADO AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DENVER COLORADO
345 AM MDT MON MAY 3 1999

...SHORT TERM DISCOURSE...
MUST BE SPRINGTIME IN COLORADO.  MDLS CONTINUE TO DIG NEGATIVELY
TILTED PAC NW TROF INTO CNTRL RCKYS THRU TUES.  MOISTURE BEGINS
TO SPRD INTO AREA TDA IN ADV OF PAC CDFNT XPCTD THRU DEN ARND 00Z.
INCRSG WNDS ALF WILL DRIVE MSTR AGNST N CNTRL MTNS AND PRODUCE SUM
GUD SNW AMTS.  OROGRAPHIC SNW MDL GAVE UP TO 19 INCHES OF SNW OVR
18 HR PRD FM NOON TDA TIL DAWN TUES MRNG.  THIS DOES NOT ACCOUNT FOR
ASSOC DYNAMICS AND THRT OF CONVECTION.  HWVR WILL GO WITH LESSER
SNW AMTS IN 8 TO 14 INCH RANGE.  LESSER AMTS OF SNW XPCTD MTN VLYS
DUE TO MELTING THIS AFTN.  WILL MENTION ONLY 3 TO 6 INCHES THERE.
STG DWNSLP SW WNDS IN AND NR FOOTHILLS TDA WITH S TO SW WNDS OVR
PLAINS.  CHINOOK BCMS A BORA TNGT AFT PASSAGE OF CDFNT.  HI WND
MDL GAVE GUSTS TO 46 KTS AT FCL ARND MIDNGT SO WNDS SHUD RMN BLO
HI WND CRITERIA.  IN SPITE OF HIGH NGM POPS AT DEN TDA WILL GO WITH
ONLY A FEW SHWRS AND TSTMS LATE AS NGM FCST UPR AIR SOUNDING GAVE NO
CAPE LATE THIS AFTN.  WILL CUT SHWRS AND TSTMS FM TDA FCST FRTHR E
ON PLAINS.  IN SPITE OF CLDNS TDA FVRD WRMR AVIATION MOS TEMP GDNC
OVR COOLER NGM AT DEN DUE TO DWNSLP FLO AND WRM OVRNGT TEMPS THIS
MRNG.

WILL EXTEND FLOOD WARNING FOR SOUTH PLATTE RIVER THRU TDA IN WELD
COUNTY.  THE GAGE AT KERSEY JUST E OF GREELEY REMAINS MORE THAN HALF
A FOOT ABV FLOOD STAGE BUT CONTINUES TO LOWER.  FLOOD WARNING
REMAINS IN EFFECT FOR TDA AND TNGT IN MORGAN COUNTY WHERE GAGE AT
WELDONA CONTS TO RISE.

GARD

...LONG TERM DISCOURSE...
LITTLE CHANGE TO PREVIOUS FCST.  MDLS BRING OPEN TROF ACRS CO
TDY/TNGT.  TROF/ CAA AND UPSLP WILL BRING SNOW AND WINDS TO MTNS
TNGT...DECRG TO SNW SHWRS TUE.  HILITES WILL BE NEEDED...SEE SHORT
TERM DISCUSSION FOR DETAILS.

IN EAST SHWRS/ TSTMS THIS EVNG WILL GIVE WAY TO BRISK NWLY FLOW
LATER TNGT.  ON TUE WITH THERMAL TROF ALF...ENUF INSTABILITY FOR A
FEW SHWRS.

ONLY CHANGE TO EXTDD WAS TO MENTION CHANCE OF SHWRS WED.  ERN CO
WILL BE ON BACKSIDE OF PLAINS UPR LOW...AND OPEN TO SHRTWV TROFS IN
NW FLOW.

GLANCY

.DEN...FLOOD WARNING TODAY...ZONE 43.
    ...FLOOD WARNING TODAY AND TONIGHT...ZONE 44.
    ...WINTER STORM WARNING THIS AFTERNOON AND TONIGHT...ZNS 33..34.

The office that day

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

Issued	Product	Office	Counties	Lasted
May 3, 11:05 AM MDT	Flash Flood Warning	BOU	Weld	7 hr
May 3, 3:55 PM MDT	Flash Flood Warning	BOU	Morgan	2 hr

Nearby

Flash Flood Warnings in Colorado, 1999 Every flash flood warning in 1999

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.