Alert archive / Arizona / Flash Flood Warnings in 1998

Flash Flood Warning 15, NWS Flagstaff, AZ

September 11, 1998Coconino County, Arizona

NWS Flagstaff, AZ issued this flash flood warning at Sep 11, 1998, 8:23 AM MST for Coconino County, Arizona. 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 counties it named.

The facts

Issued: Sep 11, 1998, 8:23 AM MST (15:23 UTC)
Expired: Sep 11, 1998, 11:25 AM MST
In force: 3 hr
Issued by: NWS Flagstaff, AZ
Area: Whole counties

County Coconino County, AZ

The radar

The Flagstaff radar (KFSX), 150 km from the middle of the area, began a volume at 15:24 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

Flgstf/Belemont, AZ (KFGZ), launched 12:00Z, 3.4 hours before the alert went out and 68 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: 1435 m above ground
0-6 km bulk shear: 38 kt
0-1 km storm-relative helicity: 31 m²/s²
0-3 km storm-relative helicity: 158 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KFLG 111527
FFWFLG
AZC005-111825-

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
823 AM MST FRI SEP 11 1998

THE NATIONAL WEATHER SERVICE IN FLAGSTAFF HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  NORTHWESTERN COCONINO COUNTY IN NORTH CENTRAL ARIZONA INCLUDING
  THE VILLAGE OF SUPAI

* UNTIL 1125 AM MST

* AT 815 AM MST...NATIONAL WEATHER SERVICE DOPPLER WEATHER RADAR
  INDICATED LOCALLY HEAVY SHOWERS AND EMBEDDED THUNDERSTORMS MOVING
  NORTH ACROSS NORTHWEST COCONINO COUNTY INCLUDING HAVASUPAI CANYON
  AND THE VILLAGE OF SUPAI.

* IN ADDITION...SPOTTER REPORTS INDICATE WATER UP TO 6 INCHES DEEP
  FLOWING IN THE CANYON AND EVACUATION OF CAMPERS IN THIS AREA ~HAS
  BEGUN.

IF YOU ARE IN THE WARNING AREA... MOVE TO HIGHER GROUND AT ONCE.
DO NOT DRIVE ACROSS WATER COVERED ROADS. AVOID ALL AREAS SUBJECT
TO FLOODING.


&

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 Flagstaff, AZ wrote its last area forecast discussion before this flash flood warning went out at Sep 11, 2:20 AM MST, 6 hours 3 minutes earlier.

Area forecast discussion, Sep 11, 2:20 AM MST, 6 hours 3 minutes before

NORTHERN ARIZONA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
220 AM MST FRI SEP 11 1998

SYNOPSIS...A UPPER LEVEL LOW PRESSURE SYSTEM ALONG THE
CALIFORNIA/NEVADA BORDER WILL KEEP A VERY MOIST SOUTHERLY FLOW ACROSS
NORTHERN ARIZONA TODAY FOR MORE CLOUDS...SHOWERS AND THUNDERSTORMS
OVER THE AREA.

DISCUSSION...TSTORMS FIRING AGAIN EARLY THIS MORNING ACROSS THE
SOUTHWESTERN PART OF THE CWFA UNDER THE RIGHT ENTRANCE REGION OF
250MB JET ACROSS NW AZ/SRN NV. CHECK OF 00Z MODELS SHOWS NGM WITH A
DECENT HANDLE ON LOW AS MAKES LITTLE PROGRESS AGAINST BROAD RIDGE
OVER THE CENTRAL US. SO VERY MOIST SOUTHERLY FLOW CONTINUES TODAY FOR
LOTS OF CLOUDS WITH HIGHEST POPS IN THE WEST. THROUGH 48 HOURS...LOW
PROGGED TO OPEN UP AND WEAKEN AS IT RIDES UP AND OVER THE RIDGE. WILL
NEED TO WORRY ABOUT REMNANTS OF FRANCES THIS WEEKEND AS IT IS
FORECAST TO BECOME AN EASTERLY WAVE WITH MOISTURE MOVING INTO EASTERN
ARIZONA. ALL THIS MEANS NORTHERN ARIZONA SHOULD STAY ON THE WET SIDE
FOR A FEW MORE DAYS. SIGLER

.FLG...NONE.

The office that day

Everything else NWS Flagstaff, AZ issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Sep 10, 7:28 PM MST	Severe Thunderstorm Warning	FGZ	Coconino	32 min
Sep 11, 11:31 AM MST	Flash Flood Warning	FGZ	Coconino	119 min
Sep 11, 1:27 PM MST	Flash Flood Warning	FGZ	Coconino	93 min

Nearby

Flash Flood Warnings in Arizona, 1998 Every 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.