Alert archive / Colorado / Mesoscale Discussions in 2012
Mesoscale Discussion 1852
The Storm Prediction Center issued this mesoscale discussion at Sep 1, 2012, 1:31 PM MST for Coconino County, Navajo County, Arizona; Dolores County, Montezuma County, San Miguel County, Colorado; Kane County, San Juan County, Utah. It was in force for 89 min.
The area
The outline as issued.
The facts
- Issued
- Sep 1, 2012, 1:31 PM MST (20:31 UTC)
- Expired
- Sep 1, 2012, 3:00 PM MST
- In force
- 89 min
- Issued by
- the Storm Prediction Center
- Chance of a watch
- 20%
Counties Coconino County, AZ, Navajo County, AZ, Dolores County, CO, Montezuma County, CO, San Miguel County, CO, Kane County, UT, San Juan County, UT
The radar
The Flagstaff radar (KFSX), 220 km from the middle of the area, began a volume at 20:30 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, 8.5 hours before the alert went out and 177 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.
- Mixed-layer CAPE
- 325 J/kg
- Mixed-layer CIN
- -86 J/kg
- Mixed-layer LCL
- 1111 m above ground
- 0-6 km bulk shear
- 29 kt
- 0-1 km storm-relative helicity
- 102 m²/s²
- 0-3 km storm-relative helicity
- 82 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.9
The text
As transmitted, in the capitals the NWS used until 2016.
207
ACUS11 KWNS 012031
SWOMCD
SPC MCD 012031
COZ000-NMZ000-AZZ000-UTZ000-012200-
MESOSCALE DISCUSSION 1852
NWS STORM PREDICTION CENTER NORMAN OK
0331 PM CDT SAT SEP 01 2012
AREAS AFFECTED...NRN AZ...SERN UT...SWRN CO
CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY
VALID 012031Z - 012200Z
PROBABILITY OF WATCH ISSUANCE...20 PERCENT
SUMMARY...ISOLATED SEVERE WIND/HAIL WILL BE POSSIBLE FOR THE
REMAINDER OF THE AFTERNOON WITH LOOSELY ORGANIZED CONVECTION. WW
ISSUANCE IS UNLIKELY.
DISCUSSION...DEEP CONVECTION HAS BEEN INCREASING ACROSS NRN AZ INTO
THE FOUR CORNERS REGION DURING THE LAST 2-3 HOURS...ON THE NRN EDGE
OF A MOISTURE PLUME EVIDENT ON WV IMAGERY. DIABATIC HEATING ALONG
WITH SUFFICIENT MOISTURE IS SUPPORTING MODERATE MUCAPE OF 1000-1500
J/KG. THIS AREA LIES ON THE SOUTHERN FRINGE OF STRONGER MIDLEVEL
FLOW ALOFT...WITH EFFECTIVE SHEAR VALUES OF 25-35 KTS NOTED IN VWP
DATA AND OBJECTIVELY ANALYZED FIELDS. THE COMBINATION OF BUOYANCY
AND SHEAR WILL SUPPORT ORGANIZED MULTICELLS AND PERHAPS TRANSIENT
SUPERCELL STRUCTURES...WITH AN ATTENDANT THREAT OF ISOLATED SEVERE
WIND AND HAIL. WITH THE SEVERE THREAT LIKELY TO REMAIN ISOLATED...WW
ISSUANCE IS NOT ANTICIPATED.
..DEAN/CORFIDI.. 09/01/2012
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...ABQ...GJT...FGZ...SLC...
LAT...LON 35701280 36281253 37091204 37731138 38421062 38690993
38570951 38450878 37960811 37290820 36500853 36120897
35360957 34961020 34701060 34461171 34511242 34841278
35701280SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Sep 1, 11:31 AM MST | Mesoscale Discussion | SPC | Beaver, Box Elder, Cache, Carbon, Davis, Duchesne and 16 more | 119 min |
| Sep 1, 11:59 AM MST | Severe Thunderstorm Watch | SPC | Beaver, Box Elder, Cache, Carbon, Davis, Duchesne and 14 more | 8 hr |
| Sep 1, 2:02 PM MST | Mesoscale Discussion | SPC | Beaver, Box Elder, Cache, Carbon, Davis, Duchesne and 15 more | 88 min |
| Sep 1, 4:49 PM MST | Mesoscale Discussion | SPC | Beaver, Box Elder, Cache, Carbon, Davis, Duchesne and 14 more | 86 min |
Nearby
Mesoscale Discussions in Colorado, 2012Mesoscale Discussions in Arizona, 2012Mesoscale Discussions in Utah, 2012Every mesoscale discussion in 2012
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.