Alert archive / Florida / Mesoscale Discussions in 2011

Mesoscale Discussion 2153

September 9, 201117 counties in Florida

The Storm Prediction Center issued this mesoscale discussion at Sep 9, 2011, 6:22 PM EDT for 17 counties in Florida. It was in force for 83 min.

The area

The outline as issued.

The facts

Issued: Sep 9, 2011, 6:22 PM EDT (22:22 UTC)
Expired: Sep 9, 2011, 7:45 PM EDT
In force: 83 min
Issued by: the Storm Prediction Center

Counties Brevard County, FL, Broward County, FL, Collier County, FL, DeSoto County, FL, Glades County, FL, Hardee County, FL, Hendry County, FL, Highlands County, FL, Indian River County, FL, Martin County, FL, Miami-Dade County, FL, Okeechobee County, FL, Orange County, FL, Osceola County, FL, Palm Beach County, FL, Polk County, FL, Saint Lucie County, FL

The radar

The Melbourne radar (KMLB), 104 km from the middle of the area, began a volume at 22:23 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

Cape Canaveral, FL (KXMR), launched 12:00Z, 10.4 hours before the alert went out and 146 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 1116 m above ground
0-6 km bulk shear: 30 kt
0-1 km storm-relative helicity: 79 m²/s²
0-3 km storm-relative helicity: 137 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

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

814 
ACUS11 KWNS 092222
SWOMCD
SPC MCD 092222 
FLZ000-092345-

MESOSCALE DISCUSSION 2153
NWS STORM PREDICTION CENTER NORMAN OK
0522 PM CDT FRI SEP 09 2011

AREAS AFFECTED...CNTRL/SRN FL PENINSULA

CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY 

VALID 092222Z - 092345Z

A FEW STORMS COULD PRODUCE GUSTY WINDS INTO EARLY EVENING.
HOWEVER...A WW IS NOT NEEDED OWING TO THE LACK OF CONVECTIVE
ORGANIZATION AND MINIMAL SVR THREAT.

SCATTERED CONVECTION CONTINUES TO MOVE ENEWD INTO PARTS OF THE WRN
FL PENINSULA ALONG A LOOSELY-DEFINED...ENEWD-MOVING OUTFLOW BOUNDARY
ARCING FROM POLK TO DESOTO TO LEE COUNTY. THIS BOUNDARY IS
ASSOCIATED WITH A DECAYING MCS THAT DEVELOPED WITHIN MOIST SWLY FLOW
OVER THE CNTRL GULF OF MEXICO EARLIER TODAY. AREA RADAR AND VISIBLE
SATELLITE IMAGERY INDICATES A REMNANT MCV OFF THE W COAST OF FL
AROUND 45 WSW OF SAINT PETERSBURG. MESOSCALE LIFT ASSOCIATED WITH
THIS FEATURE COULD AUGMENT LARGE-SCALE ASCENT WITHIN THE
RIGHT-ENTRANCE REGION OF AN UPPER-LEVEL JET MAX OVER THE SERN STATES
TO SUSTAIN THIS ACTIVITY TOWARD THE EAST COAST. AHEAD OF THIS
ACTIVITY...SCATTERED CONVECTION WILL CONTINUE IMPACTING AREAS FROM
NEAR ORLANDO TO LAKE OKEECHOBEE TO MIAMI INTO EARLY EVENING OWING TO
CONVERGENCE ALONG AGGREGATE OUTFLOW/SEA BREEZE BOUNDARIES AMIDST
MODERATE INSTABILITY. ALSO...A WEAK STATIONARY FRONT DRAPED ACROSS
PARTS OF THE CNTRL FL PENINSULA WILL BE A FOCUS FOR SCATTERED
STORMS...ESPECIALLY NEAR ITS INTERSECTION WITH THE AFOREMENTIONED
OUTFLOW BOUNDARY. GUSTY WINDS WILL BE POSSIBLE WITH COLLAPSING
STORMS...AS PW VALUES FROM 2.0 TO 2.2 INCHES PER GPS DATA WILL
SUPPORT WATER-LOADING PROCESSES. HOWEVER...WITH 20 KT OR LESS OF
FLOW WITHIN THE LOWER/MIDDLE TROPOSPHERE PER MIAMI AND MELBOURNE VWP
DATA...CONVECTION IS EXPECTED TO BE LARGELY DISORGANIZED...AND THE
SVR POTENTIAL WILL BE MINIMAL. HEAVY RAINFALL WILL ALSO BE OF
CONCERN...PARTICULARLY OVER PARTS OF SOUTH FL WHERE STORM MOTIONS
ARE EXPECTED TO BE SLOWER OWING TO WEAKER MID-LEVEL FLOW PER MIAMI
VWP DATA. STORMS ARE EXPECTED TO BEGIN WEAKENING BY 01Z OWING TO
DIABATIC COOLING.

..COHEN.. 09/09/2011

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

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

LAT...LON   27528004 26337995 25608016 25498072 26058161 26558195
            27508205 28378200 28698142 28668107 28338048 27528004

Nearby

Mesoscale Discussions in Florida, 2011 Every mesoscale discussion in 2011

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.