Alert archive / Colorado / Flash Flood Warnings in 2012
Flash Flood Warning 21, NWS Grand Junction, CO
NWS Grand Junction, CO issued this flash flood warning at Aug 23, 2012, 8:13 PM MDT for Mesa County, Colorado. It was in force for 6 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 23, 2012, 8:13 PM MDT (02:13 UTC)
- Expired
- Aug 24, 2012, 2:00 AM MDT
- In force
- 6 hr
- Issued by
- NWS Grand Junction, CO
- Area
- Storm-based polygon
- Flood severity
- None
County Mesa County, CO
The radar
The Grand Junction radar (KGJX), 36 km from the middle of the area, began a volume at 02:14 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, 2.2 hours before the alert went out and 32 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
- 176 J/kg
- Mixed-layer CIN
- -53 J/kg
- Mixed-layer LCL
- 1255 m above ground
- 0-6 km bulk shear
- 10 kt
- 0-1 km storm-relative helicity
- 4 m²/s²
- 0-3 km storm-relative helicity
- 28 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
019
WGUS55 KGJT 240213
FFWGJT
COC077-240800-
/O.NEW.KGJT.FF.W.0021.120824T0213Z-120824T0800Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE GRAND JUNCTION CO
813 PM MDT THU AUG 23 2012
THE NATIONAL WEATHER SERVICE IN GRAND JUNCTION HAS ISSUED A
* FLASH FLOOD WARNING FOR...
CENTRAL MESA COUNTY IN WEST CENTRAL COLORADO...
* UNTIL 200 AM MDT
* AT 807 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
SLOW MOVING THUNDERSTORMS WITH HEAVY RAINFALL ACROSS THE WARNED
AREA. RADAR ESTIMATES RAINFALL AMOUNTS OF ONE TO TWO INCHES OF
RAIN HAS FALLEN ON THE NORTH SIDE OF UNAWEEP CANYON OR HIGHWAY 141.
* HIGH RESOLUTION MODELS AND OBSERVATIONAL TRENDS SUGGEST AN
EXTENDED PERIOD OF STEADY RAIN WILL FALL IN THE WARNED AREA.
FLASH FLOODING IS A STRONG POSSIBILITY IN THE REMOTE CANYONS THAT
FEED INTO THE GUNNISON RIVER. EXPECT MUD DEBRIS FLOWS IN UNAWEEP
CANYON AND ON HIGHWAY 141.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
BE ESPECIALLY CAUTIOUS AT NIGHT WHEN IT IS HARDER TO RECOGNIZE THE
DANGERS OF FLOODING. IF FLASH FLOODING IS OBSERVED ACT QUICKLY. DO
NOT ENTER THE WATER. TURN AROUND AND MOVE UP TO HIGHER GROUND TO
ESCAPE FLOOD WATERS. DO NOT STAY IN AREAS SUBJECT TO FLOODING WHEN
WATER BEGINS RISING.
&&
LAT...LON 3883 10837 3877 10837 3876 10838 3876 10879
3896 10893 3896 10848 3884 10837
$$
PF2 follow-up statements
348
WGUS75 KGJT 240412
FFSGJT
FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE GRAND JUNCTION CO
1012 PM MDT THU AUG 23 2012
COC077-240800-
/O.CON.KGJT.FF.W.0021.000000T0000Z-120824T0800Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
MESA CO-
1012 PM MDT THU AUG 23 2012
...FLASH FLOOD WARNING REMAINS IN EFFECT FOR CENTRAL MESA COUNTY
UNTIL 200 AM MDT...
AT 1010 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
STEADY MODERATE HEAVY RAINFALL ACROSS THE WARNED AREA. MODEL
PROJECTIONS AND OBSERVATIONS INDICATE THAT SHOWERS WILL CONTINUE TO
IMPACT THE WARNED AREA FOR THE NEXT 2-4 HOURS.
FLOODING OF SMALL CREAKS AND DRY WASHES WITHIN DEEP CANYONS THAT
DRAIN INTO THE GUNNISON RIVER IS EXPECTED. MUD DEBRIS FLOWS ALONG
UNAWEEP CANYON AND HIGHWAY 141 WILL OCCUR.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
BE ESPECIALLY CAUTIOUS AT NIGHT WHEN IT IS HARDER TO RECOGNIZE THE
DANGERS OF FLOODING. IF FLOODING IS OBSERVED...ACT QUICKLY. DO NOT
ENTER THE WATER. TURN AROUND AND MOVE UP TO HIGHER GROUND. DO NOT
STAY IN AREAS SUBJECT TO FLOODING WHEN WATER BEGINS RISING.
&&
LAT...LON 3883 10837 3877 10837 3876 10838 3876 10879
3896 10893 3896 10848 3884 10837
$$
PF478
WGUS75 KGJT 240753
FFSGJT
FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE GRAND JUNCTION CO
153 AM MDT FRI AUG 24 2012
COC077-240808-
/O.EXP.KGJT.FF.W.0021.000000T0000Z-120824T0800Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
MESA CO-
153 AM MDT FRI AUG 24 2012
...THE FLASH FLOOD WARNING THAT WAS IN EFFECT FOR CENTRAL MESA COUNTY
WILL BE ALLOWED TO EXPIRE AT 200 AM MDT...
EXCESS RUNOFF FROM HEAVY RAIN HAS ENDED OVER THE WARNED AREA. STREAMS
AND CREEKS IN THE WARNED AREA HAVE RECEDED OR WERE BEGINNING TO
RECEDE...ENDING THE FLOOD THREAT. IF FLOODING HAS BEEN OBSERVED...
PLEASE REPORT IT TO YOUR LOCAL LAW ENFORCEMENT AGENCY.
LAT...LON 3883 10837 3877 10837 3876 10838 3876 10879
3896 10893 3896 10848 3884 10837
$$The office that day
Everything else NWS Grand Junction, CO issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 23, 7:09 PM MDT | Areal Flood Advisory | GJT | Eagle, Garfield, Gunnison, Mesa, Pitkin | 2 hr |
| Aug 23, 8:24 PM MDT | Flash Flood Warning | GJT | Eagle, Garfield, Gunnison, Mesa, Pitkin | 3 hr |
| Aug 24, 2:38 PM MDT | Special Weather Statement | GJT | Rio Blanco | 22 min |
| Aug 24, 5:25 PM MDT | Severe Thunderstorm Warning | GJT | Garfield, Mesa | 50 min |
| Aug 24, 5:32 PM MDT | Severe Thunderstorm Warning | GJT | Garfield, Mesa | 43 min |
Nearby
Flash Flood Warnings in Colorado, 2012Every flash flood warning in 2012
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.