Alert archive / Arizona / Flash Flood Warnings in 2019

Flash Flood Warning 57, NWS Flagstaff, AZ

September 1, 2019Apache County, Navajo County, Arizona

NWS Flagstaff, AZ issued this flash flood warning at Sep 1, 2019, 12:58 PM MST for Apache County, Navajo 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 1, 2019, 12:58 PM MST (19:58 UTC)
Expired
Sep 1, 2019, 3:48 PM MST
In force
3 hr
Issued by
NWS Flagstaff, AZ
Area
Storm-based polygon
Flood severity
None

Counties Apache County, AZ, Navajo County, AZ

The radar

The Flagstaff radar (KFSX), 149 km from the middle of the area, began a volume at 20:02 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, 8.0 hours before the alert went out and 173 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, Flgstf/Belemont, AZ at 12:00Z on 2019-09-01Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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, Flgstf/Belemont, AZ at 12:00Z on 2019-09-01The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -12 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
3349 m above ground
0-6 km bulk shear
8 kt
0-1 km storm-relative helicity
-12 m²/s²
0-3 km storm-relative helicity
15 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

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 1, 9:23 AM MST, 3 hours 35 minutes earlier.

Area forecast discussion, Sep 1, 9:23 AM MST, 3 hours 35 minutes before
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In the hours before

Special weather statement, Sep 1, 11:56 AM MST, 1 hour 2 minutes before
Special Weather Statement
National Weather Service Flagstaff AZ
1156 AM MST Sun Sep 1 2019

AZZ017-011930-
White Mountains-
1156 AM MST Sun Sep 1 2019

...SIGNIFICANT WEATHER ADVISORY FOR APACHE AND NAVAJO COUNTIES UNTIL
1230 PM MST...

At 1155 AM MST, Doppler radar was tracking a strong thunderstorm 11
miles east of North Fork, or 24 miles southeast of Show Low, moving
west at 10 mph.

Penny size hail and winds in excess of 30 mph will be possible with
this storm.

This storm will remain over mainly rural areas of Apache and Navajo
Counties, including the following locations... Mcnary.

LAT...LON 3379 10982 3410 10986 3403 10966 3397 10957
TIME...MOT...LOC 1855Z 088DEG 8KT 3396 10977

41
Special weather statement, Sep 1, 12:21 PM MST, 37 minutes before
Special Weather Statement
National Weather Service Flagstaff AZ
1221 PM MST Sun Sep 1 2019

AZZ017-012000-
White Mountains-
1221 PM MST Sun Sep 1 2019

...SIGNIFICANT WEATHER ADVISORY FOR APACHE AND NAVAJO COUNTIES UNTIL
100 PM MST...

At 1217 PM MST, Doppler radar was tracking a strong thunderstorm 10
miles northeast of White River.

Penny size hail and winds in excess of 30 mph will be possible with
this storm.

This storm is over the Diamond Creek and Little Diamond Creek
basins. It is expected to affect Highway 73 north of White River.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Torrential rainfall is also occurring with this storm, and may lead
to localized flooding. Do not drive your vehicle through flooded
roadways.

&&

LAT...LON 3401 10968 3387 10967 3384 10994 3402 10996
TIME...MOT...LOC 1917Z 073DEG 8KT 3391 10980

41

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 1, 11:56 AM MSTSpecial Weather StatementFGZ34 min
Sep 1, 12:21 PM MSTSpecial Weather StatementFGZ39 min
Sep 1, 1:38 PM MSTSpecial Weather StatementFGZ37 min
Sep 1, 1:58 PM MSTSpecial Weather StatementFGZ47 min
Sep 1, 2:22 PM MSTSevere Thunderstorm WarningFGZGila23 min
Sep 1, 2:29 PM MSTSpecial Weather StatementFGZ46 min
Sep 1, 2:34 PM MSTFlash Flood WarningFGZGila, Navajo3 hr
Sep 1, 2:48 PM MSTSevere Thunderstorm WarningFGZYavapai27 min
Sep 1, 3:02 PM MSTSevere Thunderstorm WarningFGZGila18 min
Sep 1, 3:24 PM MSTAreal Flood AdvisoryFGZGila3 hr
Sep 1, 3:40 PM MSTSpecial Weather StatementFGZGila50 min
Sep 1, 3:54 PM MSTSpecial Weather StatementFGZ51 min
Sep 1, 3:59 PM MSTSevere Thunderstorm WarningFGZGila, Yavapai46 min
Sep 1, 4:19 PM MSTSpecial Weather StatementFGZYavapai41 min

Nearby

Flash Flood Warnings in Arizona, 2019Every flash flood warning in 2019

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.