Alert archive / Michigan / Severe Thunderstorm Watches in 2014

Severe Thunderstorm Watch 485

September 1, 201420 counties in Michigan

The Storm Prediction Center issued this severe thunderstorm watch at Sep 1, 2014, 1:23 PM EDT for 20 counties in Michigan. It was in force for 5 hr.

The area

The outline as issued.

The facts

Issued
Sep 1, 2014, 1:23 PM EDT (17:23 UTC)
Expired
Sep 1, 2014, 6:00 PM EDT
In force
5 hr
Issued by
the Storm Prediction Center
Largest hail expected
1.5 in
Strongest gust expected
60 kt

Counties Alcona County, MI, Alpena County, MI, Antrim County, MI, Arenac County, MI, Charlevoix County, MI, Cheboygan County, MI, Chippewa County, MI, Crawford County, MI, Emmet County, MI, Gladwin County, MI, Iosco County, MI, Kalkaska County, MI, Mackinac County, MI, Missaukee County, MI, Montmorency County, MI, Ogemaw County, MI, Oscoda County, MI, Otsego County, MI, Presque Isle County, MI, Roscommon County, MI

The radar

The NCL Michigan radar (KAPX), 24 km from the middle of the area, began a volume at 17:26 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.

What SPC expected

The probabilities SPC published with the watch, for the watch area over its life.

Two or more tornadoes
10%
One or more EF2 to EF5 tornadoes
2%
Ten or more severe wind reports
30%
One or more gusts of 65 knots or more
10%
Ten or more severe hail reports
30%
One or more hailstones of 2 inches or more
10%
Six or more combined severe hail and wind reports
60%

Warnings issued inside it

11 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.

IssuedProductOfficeCountiesLasted
Sep 1, 1:52 PM EDTSevere Thunderstorm WarningAPXAntrim, Crawford, Kalkaska, Otsego53 min
Sep 1, 1:54 PM EDTTornado WarningAPXAntrim, Kalkaska24 min
Sep 1, 2:11 PM EDTTornado WarningAPXCrawford34 min
Sep 1, 2:30 PM EDTTornado WarningAPXOtsego30 min
Sep 1, 2:34 PM EDTSevere Thunderstorm WarningAPXCheboygan43 min
Sep 1, 2:42 PM EDTSevere Thunderstorm WarningAPXMontmorency, Oscoda47 min
Sep 1, 2:49 PM EDTSevere Thunderstorm WarningAPXOgemaw, Roscommon42 min
Sep 1, 2:53 PM EDTTornado Warning Tornado observedAPXMontmorency37 min
Sep 1, 2:55 PM EDTTornado WarningAPXCheboygan21 min
Sep 1, 3:05 PM EDTSevere Thunderstorm WarningAPXPresque Isle55 min
Sep 1, 3:11 PM EDTSevere Thunderstorm WarningAPXAlcona, Alpena64 min

Discussions around it

SPC mesoscale discussions over the same counties from four hours before the watch to its end.

The nearest sounding before it

Alpena, MI (KAPX), launched 12:00Z, 5.4 hours before the alert went out and 162 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 12:00Z on 2014-09-01Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 43 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 12:00Z on 2014-09-01The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 104 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
43 J/kg
Mixed-layer CIN
-133 J/kg
Mixed-layer LCL
955 m above ground
0-6 km bulk shear
31 kt
0-1 km storm-relative helicity
104 m²/s²
0-3 km storm-relative helicity
96 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Sep 1, 12:16 PM EDTMesoscale DiscussionSPCAlpena, Antrim, Arenac, Bay, Charlevoix, Cheboygan and 27 more89 min
Sep 1, 2:45 PM EDTMesoscale DiscussionSPCAlcona, Alpena, Arenac, Barry, Bay, Branch and 36 more90 min

Nearby

Severe Thunderstorm Watches in Michigan, 2014Every severe thunderstorm watch in 2014

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.