Alert archive / Florida / Mesoscale Discussions in 2012

Mesoscale Discussion 2152

December 10, 2012Osceola County, Polk County, Florida

The Storm Prediction Center issued this mesoscale discussion at Dec 10, 2012, 7:51 PM EST for Osceola County, Polk County, Florida. It was in force for 84 min.

The area

The outline as issued.

The facts

Issued
Dec 10, 2012, 7:51 PM EST (00:51 UTC)
Expired
Dec 10, 2012, 9:15 PM EST
In force
84 min
Issued by
the Storm Prediction Center
Chance of a watch
20%

Counties Osceola County, FL, Polk County, FL

The nearest sounding before it

Tampa Bay, FL (KTBW), launched 00:00Z, 0.9 hours before the alert went out and 90 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 2012-12-11Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1382 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 2012-12-11The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 242 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
1382 J/kg
Mixed-layer CIN
-30 J/kg
Mixed-layer LCL
786 m above ground
0-6 km bulk shear
41 kt
0-1 km storm-relative helicity
242 m²/s²
0-3 km storm-relative helicity
256 m²/s²
Significant tornado parameter
2.0
Supercell composite
16.4

Open this sounding in Storm Lab

The text

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

731 
ACUS11 KWNS 110051
SWOMCD
SPC MCD 110051 
FLZ000-110215-

MESOSCALE DISCUSSION 2152
NWS STORM PREDICTION CENTER NORMAN OK
0651 PM CST MON DEC 10 2012

AREAS AFFECTED...CNTRL FL PENINSULA

CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY 

VALID 110051Z - 110215Z

PROBABILITY OF WATCH ISSUANCE...20 PERCENT

SUMMARY...STORMS WILL POSE A THREAT FOR STRONG TO MARGINALLY SEVERE
WIND GUSTS AS THEY MOVE THROUGH THE CNTRL FL PENINSULA NEXT COUPLE
HOURS. WW IS NOT ANTICIPATED UNLESS TRENDS BEGIN TO SUGGEST
INTENSITIES ARE INCREASING.

DISCUSSION...NRN EXTENT OF SQUALL LINE LOCATED NEAR THE TAMPA BAY
AREA IS MOVING EAST NEAR 30 KT AND CONTINUES TO SHOW A BOWING
STRUCTURE AS WELL AS A BOOK END VORTEX NEAR ITS NRN END. THE 00Z
RAOB FROM TAMPA SHOWED A VERY WEAK CAP...MLCAPE NEAR 1500 J/KG...0-6
KM SHEAR AROUND 40 KT AND 0-1 KM STORM RELATIVE HELICITY AROUND 250
M2/S2. RADAR DATA FROM TAMPA INDICATED SUB SEVERE MAX RADIAL
VELOCITIES /BETWEEN 30 AND 40 KT/ NEAR THE SFC AT 0025Z. THE
ENVIRONMENT SHOULD REMAIN SUPPORTIVE OF ORGANIZED STRUCTURES WITHIN
THE LINE AND IS FAVORABLE FOR STORMS TO CONTINUE TO FORWARD
PROPAGATE NEXT COUPLE HOURS OR SO. ISOLATED STRONG WIND GUSTS WILL
REMAIN THE PRIMARY THREAT.

..DIAL/EDWARDS.. 12/11/2012

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

ATTN...WFO...MLB...TBW...

LAT...LON   27988090 27598209 27858220 28208212 28378109 27988090

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Dec 10, 11:34 PM ESTMesoscale DiscussionSPCCollier86 min
Dec 11, 4:55 PM ESTMesoscale DiscussionSPCBroward, DeSoto, Glades, Hendry, Highlands, Indian River and 5 more95 min

Nearby

Mesoscale Discussions in Florida, 2012Every mesoscale discussion in 2012

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.