Alert archive / Arizona / Mesoscale Discussions in 2011

Mesoscale Discussion 2154

September 10, 2011Apache County, Coconino County, Navajo County, Arizona; Cibola County, McKinley County, New Mexico

The Storm Prediction Center issued this mesoscale discussion at Sep 10, 2011, 2:41 PM MST for Apache County, Coconino County, Navajo County, Arizona; Cibola County, McKinley County, New Mexico. It was in force for 3 hr.

The area

The outline as issued.

The facts

Issued
Sep 10, 2011, 2:41 PM MST (21:41 UTC)
Expired
Sep 10, 2011, 5:15 PM MST
In force
3 hr
Issued by
the Storm Prediction Center

Counties Apache County, AZ, Coconino County, AZ, Navajo County, AZ, Cibola County, NM, McKinley County, NM

The radar

The Flagstaff radar (KFSX), 108 km from the middle of the area, began a volume at 21:44 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, 9.7 hours before the alert went out and 144 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 2011-09-10Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 74 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 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 2011-09-10The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 45 square meters per square second.1939Sfc1 km3 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
74 J/kg
Mixed-layer CIN
-53 J/kg
Mixed-layer LCL
1010 m above ground
0-6 km bulk shear
18 kt
0-1 km storm-relative helicity
45 m²/s²
0-3 km storm-relative helicity
73 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.

644 
ACUS11 KWNS 102142
SWOMCD
SPC MCD 102141
NMZ000-AZZ000-110015-

MESOSCALE DISCUSSION 2154
NWS STORM PREDICTION CENTER NORMAN OK
0441 PM CDT SAT SEP 10 2011

AREAS AFFECTED...AZ...NM

CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY

VALID 102141Z - 110015Z

EXPECT WIDELY SCATTERED TSTMS WITH SOME CHANCE FOR ISOLATED HAIL TO
AROUND 1 INCH IN DIAMETER TO PERSIST INTO THE EVENING FROM PARTS OF
NRN AZ INTO WRN SECTIONS OF NM. A WATCH DOES NOT APPEAR LIKELY GIVEN
ISOLATED NATURE OF THE LARGE HAIL THREAT.

BROADLY DIFFLUENT MID AND UPPER LEVEL FLOW FIELD EXISTS ON THE ERN
FLANK OF LARGE UPPER LOW SPINNING OFF THE COAST OF SRN CA. LARGE
SCALE ASCENT ASSOCIATED WITH DPVA AHEAD OF THE LOW...COUPLED WITH
DIURNAL DESTABILIZATION...SHOULD RESULT IN A GRADUAL INCREASE IN
SCATTERED ROBUST CONVECTION IN AN ARC FROM NW YAVAPAI COUNTY IN AZ
TO ERN CATRON AND MCKINLEY COUNTIES IN WRN NM. MOISTENING IN THE LOW
TO MID LEVELS AND MODEST MID LEVEL LAPSE RATES AROUND 7.5 C/KM PER
LATEST OBJECTIVE DATA WERE SUPPORTING MLCAPE OF 800-1100 J/KG ACROSS
THESES AREAS. WITH WEAK LOW LEVEL NLY/NELY SURFACE LOW TOPPED BY THE
SW FLOW ALOFT...EFFECTIVE SHEAR VALUES ARE SUGGESTIVE OF A KINEMATIC
REGIME THAT SHOULD SUPPORT MARGINAL SUPERCELL STRUCTURES FROM A FEW
OF THE STRONGER STORM UPDRAFTS. SPC HAIL MODEL OUTPUT FROM LATEST
FORECAST SOUNDINGS INDICATES HAIL SIZE OF 1 TO 1.5 INCHES WILL BE
POSSIBLE IN THE MORE INTENSE CORES. LIMITED DEEP-LAYER FLOW AND
SOMEWHAT COOLER BOUNDARY LAYER PRECLUDE MUCH OF A DAMAGING WIND
THREAT AND...WHEN COMBINED WITH THE SPARSE NATURE OF THE LARGE HAIL
THREAT...SUGGEST THAT A WATCH IS NOT LIKELY.

..CARBIN.. 09/10/2011

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

ATTN...WFO...ABQ...FGZ...VEF...

LAT...LON   33870849 34591036 35011225 34901303 35311335 36131213
            36411067 36390921 35490737 34450711 33870849

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Sep 10, 3:05 PM MSTMesoscale DiscussionSPCCochise, Graham, Pima, Pinal, Santa Cruz2 hr

Nearby

Mesoscale Discussions in Arizona, 2011Mesoscale Discussions in New Mexico, 2011Every 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.