Alert archive / Arizona / Flash Flood Warnings in 1998

Flash Flood Warning 8, NWS Flagstaff, AZ

July 31, 1998Gila County, Arizona

NWS Flagstaff, AZ issued this flash flood warning at Jul 31, 1998, 12:54 PM MST for Gila County, Arizona. 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 counties it named.

The facts

Issued
Jul 31, 1998, 12:54 PM MST (19:54 UTC)
Expired
Jul 31, 1998, 3:00 PM MST
In force
2 hr
Issued by
NWS Flagstaff, AZ
Area
Whole counties

County Gila County, AZ

The radar

The Flagstaff radar (KFSX), 93 km from the middle of the area, began a volume at 19:58 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

Phoenix, AZ (KPHX), launched 12:00Z, 7.9 hours before the alert went out and 115 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-pSkew-T log-p diagram, Phoenix, AZ at 12:00Z on 1998-07-31Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 493 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Phoenix, AZ at 12:00Z on 1998-07-31The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 43 square meters per square second.1939Sfc1 km3 km6 km9 kmRMLM
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
493 J/kg
Mixed-layer CIN
-209 J/kg
Mixed-layer LCL
1757 m above ground
0-6 km bulk shear
27 kt
0-1 km storm-relative helicity
43 m²/s²
0-3 km storm-relative helicity
19 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 311958
FFWFLG
AZC007-312155-

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
1254 PM MST FRI JUL 31 1998

THE NATIONAL WEATHER SERVICE IN FLAGSTAFF HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  NORTHEASTERN GILA COUNTY IN CENTRAL ARIZONA

* UNTIL 300 PM MST

* AT 1250 PM MST...FLAGSTAFF DOPPLER RADAR SHOWED A NEARLY
  STATIONARY STRONG THUNDERSTORM PRODUCING VERY HEAVY RAINFALL
  NEAR CANYON DAY...JUST WEST OF FORT APACHE. RADAR ESTIMATED OVER
  3 INCHES OF RAIN WITH THIS STORM SINCE NOON MST.

* DANGEROUS RAPID RISES IN WATER LEVELS OF WASHES AND CREEKS
  FEEDING INTO THE WHITE RIVER NEAR CANYON DAY AND HIGHWAY 73 ARE
  LIKELY THROUGH 3 PM MST.

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 Jul 31, 9:00 AM MST, 3 hours 54 minutes earlier.

Area forecast discussion, Jul 31, 9:00 AM MST, 3 hours 54 minutes before
NORTHERN ARIZONA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
900 AM MST FRI JUL 31 1998

SYNOPSIS...DRIER AIR WILL BE MOVING OVER NORTHERN ARIZONA FOR
DECREASED THUNDERSTORM ACTIVITY TODAY...PARTICULARLY IN THE WESTERN
SECTIONS OF THE STATE...WITH PARTLY CLOUDY SKIES AND ONLY ISOLATED
THUNDERSTORMS IN THE EAST. DAYTIME TEMPERATURES WILL SHOW LITTLE
CHANGE INTO THE WEEKEND.

DISCUSSION...FAIRLY DECENT DRYING HAS OCCURRED OVER MOST OF THE
WESTERN PORTION OF THE CWA. RESIDUAL MOISTURE REMAINS OVER EASTERN
YAVAPAI COUNTY...AND FROM FLAGSTAFF...TO THE EAST. WITH DECENT CAP
NOTED ON 12Z FLG SOUNDING...THE RACE IS ON TO SEE IF DAYTIME
HEATING...AND LOW LEVEL MOISTURE WILL COMBINE TO CAUSE DEVELOPMENT
OVER EASTERN YAVAPAI COUNTY...AND THE WESTERN RIM AREA BEFORE IT
MOVES OUT OF THE AREA TO THE EAST. FOR NOW WILL BET THAT DAYTIME
HEATING WILL WIN OUT...AND WILL INTRODUCE SOME ISOLATED POPS INTO
FCST PACKAGE OVER ZONE 15 AND EASTERN PORTIONS OF ZN 8. ALREADY A FEW
CU HERE STARTING TO SHOW SIGNS THAT THEY MAY BUST THROUGH CAP.
OTHERWISE FCSTS IN GOOD SHAPE. MCGRATH
FLG -0-  INW 0--
.FLG...NONE.

In the hours before

Special weather statement, Jul 31, 9:05 AM MST, 3 hours 49 minutes before
AZZ004>018-311900-

AREA THUNDERSTORM OUTLOOK
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
905 AM MST FRI JUL 31 1998

...ISOLATED THUNDERSTORMS EXPECTED OVER THE MOUNTAINS OF EAST CENTRAL
ARIZONA TODAY...

SPOTTER ACTIVATION SHOULD NOT BE REQUIRED TODAY.

DISCUSSION...DRYER AIR WILL CONTINUE TO SETTLE IN OVER MOST OF
NORTHERN ARIZONA TODAY...AS A DISTURBANCE PASSES TO OUR NORTH. THIS
DISTURBANCE WILL INCREASE DRY SOUTHWEST FLOW AT THE MID LEVELS. NEAR
THE SURFACE...SOME MOISTURE REMAINS...BUT NOT QUITE ENOUGH TO CAUSE
THUNDERSTORM DEVELOPMENT OVER MOST OF NORTHERN ARIZONA.

HOWEVER... AREAS SUCH AS THE WHITE MOUNTAINS AND ALONG THE MOGOLLON
RIM EAST OF FLAGSTAFF WILL SEE SOME ISOLATED SHOWERS AND
THUNDERSTORMS BY EARLY THIS AFTERNOON. THESE THUNDERSTORMS ARE NOT
EXPECTED TO REACH SEVERE LIMITS. MCGRATH

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 31, 2:29 PM MSTSevere Thunderstorm WarningFGZNavajo46 min
Jul 31, 2:29 PM MSTSevere Thunderstorm WarningFGZApache46 min
Jul 31, 3:27 PM MSTFlash Flood WarningFGZNavajo2 hr

Nearby

Flash Flood Warnings in Arizona, 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.