Alert archive / Michigan / Mesoscale Discussions in 2006

Mesoscale Discussion 1621

July 24, 20068 counties in Michigan

The Storm Prediction Center issued this mesoscale discussion at Jul 24, 2006, 10:21 PM EDT for 8 counties in Michigan. It was in force for 84 min.

The area

The outline as issued.

The facts

Issued
Jul 24, 2006, 10:21 PM EDT (02:21 UTC)
Expired
Jul 24, 2006, 11:45 PM EDT
In force
84 min
Issued by
the Storm Prediction Center

Counties Alcona County, MI, Alpena County, MI, Arenac County, MI, Iosco County, MI, Montmorency County, MI, Ogemaw County, MI, Oscoda County, MI, Presque Isle County, MI

The radar

The NCL Michigan radar (KAPX), 87 km from the middle of the area, began a volume at 02:20 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

Alpena, MI (KAPX), launched 00:00Z, 2.4 hours before the alert went out and 107 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, Alpena, MI at 00:00Z on 2006-07-25Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2225 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, Alpena, MI at 00:00Z on 2006-07-25The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 94 square meters per square second.193958Sfc1 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
2225 J/kg
Mixed-layer CIN
-4 J/kg
Mixed-layer LCL
860 m above ground
0-6 km bulk shear
17 kt
0-1 km storm-relative helicity
94 m²/s²
0-3 km storm-relative helicity
137 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.

000 
ACUS11 KWNS 250222
SWOMCD
SPC MCD 250221 
MIZ000-250345-

MESOSCALE DISCUSSION 1621
NWS STORM PREDICTION CENTER NORMAN OK
0921 PM CDT MON JUL 24 2006

AREAS AFFECTED...NRN LOWER MI

CONCERNING...SEVERE THUNDERSTORM WATCH 640...

VALID 250221Z - 250345Z

THE THREAT FOR ISOLATED DAMAGING WIND GUSTS IS EXPECTED TO PERSIST
ANOTHER HOUR OR TWO WITH CLUSTERS OF STORMS DEVELOPING OVER THE NRN
TIP OF LOWER MI. CONFIDENCE IS LOW THAT ADDITIONAL STRONG STORMS
WILL DEVELOP FARTHER S.  

SMALL CLUSTER OF STORMS CONTINUES MOVING EWD THROUGH EXTREME NRN
LOWER MI. THE ATMOSPHERE REMAINS MODERATELY UNSTABLE. HOWEVER...SWD
EXTENTION OF OUTFLOW BOUNDARY REMAINS LARGELY FREE OF THUNDERSTORMS.
THE ORIENTATION OF THE WLY LOW LEVEL JET RELATIVE TO THE EWD MOVING
OUTFLOW BOUNDARY APPEARS TO BE LIMITING DEEP LAYER CONVERGENCE. THIS
ALONG WITH THE STABILIZING BOUNDARY LAYER LOWERS CONFIDENCE THAT
ADDITIONAL STRONG STORMS WILL DEVELOP FARTHER S.

..DIAL.. 07/25/2006

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

ATTN...WFO...APX...

45078310 44358316 44038371 44148441 44768444 45528365

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jul 25, 7:10 PM EDTSevere Thunderstorm WatchSPCBaraga, Dickinson, Gogebic, Houghton, Iron, Marquette and 2 more6 hr

Nearby

Mesoscale Discussions in Michigan, 2006Every mesoscale discussion in 2006

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.