Alert archive / Utah / Flash Flood Warnings in 2003

Flash Flood Warning 21, NWS Grand Junction, CO

August 14, 2003San Juan County, Utah

NWS Grand Junction, CO issued this flash flood warning at Aug 14, 2003, 8:25 PM MDT for San Juan County, Utah. It was in force for 3 hr. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued: Aug 14, 2003, 8:25 PM MDT (02:25 UTC)
Expired: Aug 14, 2003, 11:15 PM MDT
In force: 3 hr
Issued by: NWS Grand Junction, CO
Area: Counties, with a storm outline in the text

County San Juan County, UT

The radar

The Grand Junction radar (KGJX), 167 km from the middle of the area, began a volume at 02:27 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

Grand Junction, CO (KGJT), launched 00:00Z, 2.4 hours before the alert went out and 160 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: 562 J/kg
Mixed-layer CIN: -96 J/kg
Mixed-layer LCL: 3586 m above ground
0-6 km bulk shear: 26 kt
0-1 km storm-relative helicity: 43 m²/s²
0-3 km storm-relative helicity: 94 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.8

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

000 
WGUS55 KGJT 150227
FFWGJT
UTC037-150515-

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE GRAND JUNCTION CO
825 PM MDT THU AUG 14 2003

THE NATIONAL WEATHER SERVICE IN GRAND JUNCTION HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  EAST CENTRAL SAN JUAN COUNTY IN SOUTHEAST UTAH
  THIS INCLUDES THE CITY OF MONTICELLO

* UNTIL 1115 PM MDT

* AT 820 PM MDT...THE PUBLIC REPORTED VERY HEAVY RAIN OVER           
                  MONTICELLO...MOVING WEST AT 20 MPH.

EXCESSIVE RUNOFF FROM THIS STORM WILL CAUSE FLASH FLOODING OF SMALL 
CREEKS INCLUDING SOUTH CREEK OR VEGA CREEK...AND NEAR MONTICELLO 
WHERE THESE CREEKS CROSS HIGHWAY 191.

DO NOT DRIVE YOUR VEHICLE INTO AREAS WHERE THE WATER COVERS THE
ROADWAY. THE WATER DEPTH MAY BE TOO GREAT TO ALLOW YOUR CAR TO CROSS
SAFELY. VEHICLES CAUGHT IN RISING WATER SHOULD BE ABANDONED QUICKLY.
MOVE TO HIGHER GROUND.

LAT...LON 3782 10929 3790 10929 3792 10943 3782 10944

1 follow-up statement

000 
RWUS32 KGJT 150514
FFSGJT
UTC037-150715-

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE GRAND JUNCTION CO
1115 PM MDT THU AUG 14 2003

...THE FLASH FLOOD WARNING WHICH WAS IN EFFECT UNTIL 1115 PM MDT FOR 
EASTERN SAN JUAN COUNTY HAS BEEN ALLOWED TO EXPIRE...

THE HEAVY RAIN HAS ENDED OVER THE WARNED AREA AND THE SAN JUAN 
COUNTY SHERIFFS OFFICE REPORTED ONLY MINOR FLOODING. STILL SOME 
ROADWAYS MAY BE COVERED WITH WATER. MOTORISTS ARE ADVISED TO AVOID 
DRIVING THROUGH FLOODED ROADWAYS.

BE ESPECIALLY CAUTIOUS AT NIGHT WHEN IT IS HARDER TO RECOGNIZE THE
DANGERS OF FLOODS AND FLASH FLOODS. IF FLASH FLOODING IS OBSERVED ACT
QUICKLY. MOVE UP TO HIGHER GROUND TO ESCAPE FLOOD WATERS. DO NOT STAY
IN AREAS SUBJECT TO FLOODING WHEN WATER BEGINS RISING.

Nearby

Flash Flood Warnings in Utah, 2003 Every flash flood warning in 2003

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.