Alert archive / Florida / Mesoscale Discussions in 2015

Mesoscale Discussion 487

April 29, 2015Collier County, Miami-Dade County, Monroe County, Florida

The Storm Prediction Center issued this mesoscale discussion at Apr 29, 2015, 12:48 AM EDT for Collier County, Miami-Dade County, Monroe County, Florida. It was in force for 87 min.

The area

The outline as issued.

The facts

Issued
Apr 29, 2015, 12:48 AM EDT (04:48 UTC)
Expired
Apr 29, 2015, 2:15 AM EDT
In force
87 min
Issued by
the Storm Prediction Center
Chance of a watch
20%

Counties Collier County, FL, Miami-Dade County, FL, Monroe County, FL

The radar

The Key West radar (KBYX), 160 km from the middle of the area, began a volume at 04:51 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

Miami, FL (KMFL), launched 00:00Z, 4.8 hours before the alert went out and 203 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, Miami, FL at 00:00Z on 2015-04-29Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 645 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, Miami, FL at 00:00Z on 2015-04-29The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 190 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
645 J/kg
Mixed-layer CIN
-22 J/kg
Mixed-layer LCL
691 m above ground
0-6 km bulk shear
51 kt
0-1 km storm-relative helicity
190 m²/s²
0-3 km storm-relative helicity
273 m²/s²
Significant tornado parameter
0.9
Supercell composite
5.3

Open this sounding in Storm Lab

The text

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

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SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 29, 4:57 AM EDTMesoscale DiscussionSPCMiami-Dade2 hr

Nearby

Mesoscale Discussions in Florida, 2015Every mesoscale discussion in 2015

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.