Alert archive / Florida / Mesoscale Discussions in 2017

Mesoscale Discussion 1104

June 20, 2017Baldwin County, Mobile County, Alabama; 10 counties in Florida; Harrison County, Jackson County, Mississippi

The Storm Prediction Center issued this mesoscale discussion at Jun 20, 2017, 8:15 PM CDT for Baldwin County, Mobile County, Alabama; 10 counties in Florida; Harrison County, Jackson County, Mississippi. It was in force for 3 hr.

The area

The outline as issued.

The facts

Issued
Jun 20, 2017, 8:15 PM CDT (01:15 UTC)
Expired
Jun 20, 2017, 10:45 PM CDT
In force
3 hr
Issued by
the Storm Prediction Center
Chance of a watch
20%

Counties Baldwin County, AL, Mobile County, AL, Bay County, FL, Calhoun County, FL, Escambia County, FL, Gulf County, FL, Holmes County, FL, Liberty County, FL, Okaloosa County, FL, Santa Rosa County, FL, Walton County, FL, Washington County, FL, Harrison County, MS, Jackson County, MS

The radar

The Eglin Afb radar (KEVX), 101 km from the middle of the area, began a volume at 01:16 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 watches that followed

Watches SPC issued over any of the same counties within four hours of this discussion.

The nearest sounding before it

Slidell Radar S, LA (KSIL), launched 00:00Z, 1.3 hours before the alert went out and 264 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, Slidell Radar S, LA at 00:00Z on 2017-06-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 18 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, Slidell Radar S, LA at 00:00Z on 2017-06-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 63 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
18 J/kg
Mixed-layer CIN
-97 J/kg
Mixed-layer LCL
541 m above ground
0-6 km bulk shear
28 kt
0-1 km storm-relative helicity
63 m²/s²
0-3 km storm-relative helicity
-21 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

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SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jun 20, 9:48 PM CDTMesoscale DiscussionSPCBaldwin, Mobile57 min
Jun 20, 10:24 PM CDTTornado WatchSPCBaldwin, Mobile12 hr
Jun 21, 2:08 AM CDTMesoscale DiscussionSPCBaldwin, Mobile2 hr
Jun 21, 7:47 AM CDTMesoscale DiscussionSPCBaldwin, Mobile118 min
Jun 21, 10:01 AM CDTTornado WatchSPCBaldwin, Covington, Escambia, Mobile9 hr
Jun 21, 3:42 PM CDTMesoscale DiscussionSPCBaldwin, Mobile93 min
Jun 21, 6:29 PM CDTMesoscale DiscussionSPCBaldwin, Conecuh, Covington, Escambia, Mobile, Washington61 min
Jun 21, 6:45 PM CDTTornado WatchSPCBaldwin, Butler, Clarke, Conecuh, Covington, Crenshaw and 5 more8 hr

Nearby

Mesoscale Discussions in Florida, 2017Mesoscale Discussions in Alabama, 2017Mesoscale Discussions in Mississippi, 2017Every mesoscale discussion in 2017

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.