Alert archive / Florida / Mesoscale Discussions in 2017

Mesoscale Discussion 24

January 7, 201711 counties in Florida

The Storm Prediction Center issued this mesoscale discussion at Jan 7, 2017, 12:08 AM EST for 11 counties in Florida. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued
Jan 7, 2017, 12:08 AM EST (05:08 UTC)
Expired
Jan 7, 2017, 2:15 AM EST
In force
2 hr
Issued by
the Storm Prediction Center
Chance of a watch
20%

Counties Alachua County, FL, Citrus County, FL, Dixie County, FL, Gilchrist County, FL, Hernando County, FL, Hillsborough County, FL, Lafayette County, FL, Levy County, FL, Marion County, FL, Pasco County, FL, Sumter County, FL

The radar

The Tampa radar (KTBW), 158 km from the middle of the area, began a volume at 05:10 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

Tampa Bay, FL (KTBW), launched 00:00Z, 5.1 hours before the alert went out and 158 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, Tampa Bay, FL at 00:00Z on 2017-01-07Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 15 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, Tampa Bay, FL at 00:00Z on 2017-01-07The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 131 square meters per square second.1939587897Sfc1 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
15 J/kg
Mixed-layer CIN
-200 J/kg
Mixed-layer LCL
1455 m above ground
0-6 km bulk shear
50 kt
0-1 km storm-relative helicity
131 m²/s²
0-3 km storm-relative helicity
163 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.2

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
Jan 7, 12:33 AM ESTTornado WatchSPCCitrus, Dixie, Hernando, Hillsborough, Levy, Manatee and 5 more4 hr
Jan 7, 3:58 AM ESTMesoscale DiscussionSPCCitrus, Hernando, Hillsborough, Levy, Manatee, Pasco and 3 more92 min

Nearby

Mesoscale Discussions in Florida, 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.