Alert archive / Florida / Mesoscale Discussions in 2012

Mesoscale Discussion 450

April 4, 20128 counties in Florida

The Storm Prediction Center issued this mesoscale discussion at Apr 4, 2012, 10:03 PM EDT for 8 counties in Florida. It was in force for 57 min.

The area

The outline as issued.

The facts

Issued
Apr 4, 2012, 10:03 PM EDT (02:03 UTC)
Expired
Apr 4, 2012, 11:00 PM EDT
In force
57 min
Issued by
the Storm Prediction Center

Counties Charlotte County, FL, Collier County, FL, DeSoto County, FL, Hillsborough County, FL, Lee County, FL, Manatee County, FL, Monroe County, FL, Sarasota County, FL

The radar

The Miami radar (KAMX), 156 km from the middle of the area, began a volume at 02:03 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, 2.1 hours before the alert went out and 157 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 2012-04-05Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1125 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 2012-04-05The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 56 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
1125 J/kg
Mixed-layer CIN
-102 J/kg
Mixed-layer LCL
1159 m above ground
0-6 km bulk shear
34 kt
0-1 km storm-relative helicity
56 m²/s²
0-3 km storm-relative helicity
65 m²/s²
Significant tornado parameter
0.1
Supercell composite
1.0

Open this sounding in Storm Lab

The text

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

516 
ACUS11 KWNS 050204
SWOMCD
SPC MCD 050203
FLZ000-050300-

MESOSCALE DISCUSSION 0450
NWS STORM PREDICTION CENTER NORMAN OK
0903 PM CDT WED APR 04 2012

AREAS AFFECTED...WRN FL COAST...FL KEYS

CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY

VALID 050203Z - 050300Z

A WIND DAMAGE THREAT WILL DEVELOP ALONG THE WEST COAST OF FL THIS
EVENING WITH THE THREAT SPREADING SWD WITH TIME. THE THREAT SHOULD
REMAIN ISOLATED AND WW ISSUANCE IS NOT EXPECTED.

A LINE OF STRONG TO SEVERE THUNDERSTORMS IS ONGOING JUST TO THE WEST
OF TAMPA BAY EXTENDING SOUTHWEST INTO THE GULF OF MEXICO ABOUT 200
STATUTE MILES. THE LINE IS BEING SUPPORTED BY A SHORTWAVE TROUGH
EVIDENT ON WATER VAPOR IMAGERY AND IS LOCATED ALONG THE ERN EDGE OF
AN AXIS OF MODERATE INSTABILITY. SFC DEWPOINTS ALONG THE WEST COAST
OF FL ARE IN THE LOWER 70S F ALONG WITH STEEP LOW-LEVEL LAPSE RATES
EVIDENT ON THE TAMPA BAY 00Z SOUNDING. THIS ENVIRONMENT SHOULD BE
FAVORABLE FOR STRONG TO POTENTIALLY DAMAGING WINDS. THE LINE SHOULD
WEAKEN AFTER MOVING INLAND DUE TO WEAKER INSTABILITY ACROSS THE
PENINSULA. HOWEVER...MODERATE INSTABILITY ALONG THE SW COAST SHOULD
ENABLE THE LINE TO INTENSIFY SWD WITH TIME EVENTUALLY AFFECTING SRN
FL AND THE FL KEYS LATE THIS EVENING.

..BROYLES.. 04/05/2012

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

ATTN...WFO...MFL...KEY...TBW...

LAT...LON   24968073 25588095 26328151 27298182 27978205 28108246
            27878278 27138267 26108228 25078172 24738126 24968073

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 5, 2:10 AM EDTMesoscale DiscussionSPCMiami-Dade, Monroe3 hr
Apr 5, 10:14 AM EDTSevere Thunderstorm WatchSPCEscambia, Okaloosa, Santa Rosa8 hr
Apr 5, 2:12 PM EDTMesoscale DiscussionSPCCalhoun, Gadsden, Holmes, Jackson, Liberty, Okaloosa and 3 more93 min
Apr 5, 2:58 PM EDTSevere Thunderstorm WatchSPCBay, Calhoun, Franklin, Gadsden, Gulf, Holmes and 6 more6 hr
Apr 5, 4:49 PM EDTMesoscale DiscussionSPCCalhoun, Escambia, Gadsden, Holmes, Jackson, Leon and 5 more86 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; radar from the NEXRAD Level II archive.