Alert archive / Arizona / Mesoscale Discussions in 2011

Mesoscale Discussion 2172

September 13, 2011Yuma County, Arizona

The Storm Prediction Center issued this mesoscale discussion at Sep 13, 2011, 12:29 PM MST for Yuma County, Arizona. It was in force for 61 min.

The area

The outline as issued.

The facts

Issued
Sep 13, 2011, 12:29 PM MST (19:29 UTC)
Expired
Sep 13, 2011, 1:30 PM MST
In force
61 min
Issued by
the Storm Prediction Center

County Yuma County, AZ

The radar

The Yuma radar (KYUX), 37 km from the middle of the area, began a volume at 19:32 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

Yuma Prvg Ground, AZ (K1Y7), launched 12:00Z, 7.5 hours before the alert went out and 13 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, Yuma Prvg Ground, AZ at 12:00Z on 2011-09-13Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 555 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Yuma Prvg Ground, AZ at 12:00Z on 2011-09-13The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 87 square meters per square second.19395878Sfc1 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
555 J/kg
Mixed-layer CIN
-307 J/kg
Mixed-layer LCL
1873 m above ground
0-6 km bulk shear
29 kt
0-1 km storm-relative helicity
87 m²/s²
0-3 km storm-relative helicity
161 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.4

Open this sounding in Storm Lab

The text

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

469 
ACUS11 KWNS 131930
SWOMCD
SPC MCD 131929
AZZ000-CAZ000-132030-

MESOSCALE DISCUSSION 2172
NWS STORM PREDICTION CENTER NORMAN OK
0229 PM CDT TUE SEP 13 2011

AREAS AFFECTED...LOWER CO RIVER VALLEY AND GILA RIVER VALLEY

CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY

VALID 131929Z - 132030Z

THE THREAT FOR A FEW STORMS CAPABLE OF LARGE HAIL/DMGG WIND GUST MAY
INCREASE INVOF THE CONFLUENCE OF THE GILA AND COLORADO RIVERS IN FAR
SWRN AZ AND FAR SERN CA NEAR THE MEXICAN BORDER.

RECENT KYUX RADAR TRENDS HAVE SHOWN A FEW DEVELOPING STORMS
ACQUIRING MIDLEVEL ROTATION S OF THE BORDER NEAR NRN TIP OF THE GULF
OF CALIFORNIA.  CONVECTIVE OUTFLOW EMANATING FROM ONGOING CONVECTIVE
CLUSTER OVER RIVERSIDE COUNTY CA WILL LIKELY ACT TO LIMIT THE AREAL
NWD EXTENT OF MODERATE INSTABILITY TO BE S OF THE BORDER.  THE 18Z
1Y7 /YUMA/ RAOB FEATURES STEEP LAPSE RATES AND MOIST MID-LEVELS WITH
35 KTS H5 FLOW--SUPPORTIVE OF SOME STORM ORGANIZATION.  WITH THE
UPPER LOW/VORT MAX LOCATED TO THE W ONLY EXPECTED TO MAKE GRADUAL
EWD PROGRESS DURING THE NEXT FEW HOURS...THIS REGION WILL REMAIN
WITHIN A BELT OF STRONGER DEEP LAYER SHEAR AND FORCING FOR ASCENT ON
THE ERN SIDE OF THE UPPER LOW...AND ACT TO PROMOTE A MODEST SEVERE
RISK THROUGH THE AFTERNOON HOURS.

..SMITH.. 09/13/2011

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

ATTN...WFO...PSR...

LAT...LON   32631499 32951475 32981422 32691349 32111334 31981350
            32381487 32631499

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Sep 13, 7:15 AM MSTMesoscale DiscussionSPCMohave90 min

Nearby

Mesoscale Discussions in Arizona, 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.