Alert archive / Arizona / Mesoscale Discussions in 2011

Mesoscale Discussion 2177

September 14, 2011Coconino County, Navajo County, Arizona; Kane County, Washington County, Utah

The Storm Prediction Center issued this mesoscale discussion at Sep 14, 2011, 12:16 PM MST for Coconino County, Navajo County, Arizona; Kane County, Washington County, Utah. It was in force for 89 min.

The area

The outline as issued.

The facts

Issued: Sep 14, 2011, 12:16 PM MST (19:16 UTC)
Expired: Sep 14, 2011, 1:45 PM MST
In force: 89 min
Issued by: the Storm Prediction Center

Counties Coconino County, AZ, Navajo County, AZ, Kane County, UT, Washington County, UT

The radar

The Cedar City radar (KICX), 165 km from the middle of the area, began a volume at 19:16 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, 7.3 hours before the alert went out and 132 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: 224 J/kg
Mixed-layer CIN: -8 J/kg
Mixed-layer LCL: 729 m above ground
0-6 km bulk shear: 38 kt
0-1 km storm-relative helicity: 45 m²/s²
0-3 km storm-relative helicity: 64 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.1

Open this sounding in Storm Lab

The text

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

342 
ACUS11 KWNS 141917
SWOMCD
SPC MCD 141916
AZZ000-UTZ000-142045-

MESOSCALE DISCUSSION 2177
NWS STORM PREDICTION CENTER NORMAN OK
0216 PM CDT WED SEP 14 2011

AREAS AFFECTED...NRN AZ...SRN UT

CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY

VALID 141916Z - 142045Z

A MARGINAL SEVERE THREAT SHOULD CONTINUE TO DEVELOP ACROSS NRN AZ
AND MAY SPREAD NWD INTO SRN UT THIS AFTERNOON. HAIL AND STRONG GUSTY
WIND WILL BE THE PRIMARY THREATS. A WW ISSUANCE IS NOT EXPECTED DUE
TO THE MARGINAL NATURE OF THE THREATS.

SCATTERED THUNDERSTORMS ARE INCREASING IN COVERAGE ACROSS NRN AZ
ALONG THE MOGOLLON RIM NEAR A MAXIMUM OF MODERATE INSTABILITY WHERE
MLCAPE VALUES ARE ESTIMATED IN THE 1200 TO 1800 J/KG RANGE. THE
STORMS ARE BEING SUPPORTED BY LARGE-SCALE ASCENT JUST AHEAD OF THE
AXIS OF AN UPPER-LEVEL TROUGH ORIENTED FROM SRN NV SWD INTO SERN CA.
CONTINUED DESTABILIZATION AND COLD AIR ALOFT WITH THE UPPER-LEVEL
TROUGH WILL RESULT IN STEEP LAPSE RATES...FAVORABLE FOR HAIL WITH
THE STRONGER CORES. AS LOW-LEVEL LAPSE RATES STEEPEN...A THREAT FOR
MARGINALLY SEVERE DAMAGING WIND GUSTS MAY ALSO DEVELOP. THE THREAT
SHOULD REMAIN ISOLATED AND CONCENTRATED NEAR THE INSTABILITY MAX IN
NRN AZ.

..BROYLES.. 09/14/2011

...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...

ATTN...WFO...GJT...FGZ...SLC...VEF...

LAT...LON   36420963 36881029 37181135 37501261 37671342 37341392
            37021386 36691362 35911286 35321223 34941108 34891018
            35600953 36420963

Nearby

Mesoscale Discussions in Arizona, 2011 Mesoscale Discussions in Utah, 2011 Every mesoscale discussion in 2011

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.