Alert archive / Arizona / Winter Storm Warnings in 2018

Winter Storm Warning 1, NWS Flagstaff, AZ

February 18, 2018Apache County, Coconino County, Navajo County, Arizona

NWS Flagstaff, AZ issued this winter storm warning at Feb 18, 2018, 3:37 AM MST for Apache County, Coconino County, Navajo County, Arizona. It took effect at Feb 19, 2018, 12:00 AM MST. It was in force for 12 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: Feb 18, 2018, 3:37 AM MST (10:37 UTC)
In effect from: Feb 19, 2018, 12:00 AM MST
Expired: Feb 19, 2018, 12:16 PM MST
In force: 12 hr
Issued by: NWS Flagstaff, AZ

Counties Apache County, AZ, Coconino County, AZ, Navajo County, AZ

The radar

The Flagstaff radar (KFSX), 124 km from the middle of the area, began a volume at 10:40 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 00:00Z, 10.6 hours before the alert went out and 121 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: 2173 m above ground
0-6 km bulk shear: 9 kt
0-1 km storm-relative helicity: -13 m²/s²
0-3 km storm-relative helicity: -12 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 winter storm 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 winter storm warning went out at Feb 17, 9:15 PM MST, 6 hours 22 minutes earlier.

Area forecast discussion, Feb 17, 9:15 PM MST, 6 hours 22 minutes before

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The office that day

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

Issued	Product	Office	Counties	Lasted
Feb 18, 3:37 AM MST	Winter Weather Advisory	FGZ	Apache, Coconino, Navajo	49 hr
Feb 18, 11:44 AM MST	High Wind Warning	FGZ	Apache, Coconino, Navajo	29 hr

Nearby

Winter Storm Warnings in Arizona, 2018 Every winter storm warning in 2018

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.