Alert archive / Florida / Mesoscale Discussions in 2021

Mesoscale Discussion 148

March 6, 2021Miami-Dade County, Florida

The Storm Prediction Center issued this mesoscale discussion at Mar 6, 2021, 4:27 PM EST for Miami-Dade County, Florida. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued
Mar 6, 2021, 4:27 PM EST (21:27 UTC)
Expired
Mar 6, 2021, 6:30 PM EST
In force
2 hr
Issued by
the Storm Prediction Center
Concerning
Severe potential...watch unlikely
Chance of a watch
5%

County Miami-Dade County, FL

The radar

The Miami radar (KAMX), 40 km from the middle of the area, began a volume at 21:31 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 12:00Z, 9.5 hours before the alert went out and 18 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 12:00Z on 2021-03-06Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2 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 12:00Z on 2021-03-06The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -11 square meters per square second.1939587897117Sfc1 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
2 J/kg
Mixed-layer CIN
-24 J/kg
Mixed-layer LCL
1349 m above ground
0-6 km bulk shear
63 kt
0-1 km storm-relative helicity
-11 m²/s²
0-3 km storm-relative helicity
171 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

459 
ACUS11 KWNS 062127
SWOMCD
SPC MCD 062127 
FLZ000-062330-

Mesoscale Discussion 0148
NWS Storm Prediction Center Norman OK
0327 PM CST Sat Mar 06 2021

Areas affected...southeast FL Coastal Areas

Concerning...Severe potential...Watch unlikely 

Valid 062127Z - 062330Z

Probability of Watch Issuance...5 percent

SUMMARY...Isolated strong/severe storms will be possible through
early evening. Strong winds and hail will be possible with the
strongest storms.

DISCUSSION...A small area of thunderstorms has developed over
Broward and Miami-Dade counties during the past 1-2 hours, aided by
diurnal heating that has contributed to 500-700 J/kg of MLCAPE
across coastal sections of southeast FL. Strong westerly mid-level
flow has resulted in long hodographs and 55-60 kts of westerly
deep-layer shear, supportive of storm organization. Additional
thunderstorm development remains possible through early evening,
with relatively cool mid-level thermal profiles favorable for hail
with a few stronger storms.  Gusty winds will also be possible
before storms weaken with time this evening.

A watch is not anticipated due to the expected sparse coverage of
the severe risk.

..Bunting/Guyer.. 03/06/2021

...Please see www.spc.noaa.gov for graphic product...

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

LAT...LON   25347992 25318037 25638056 26168039 26368022 26377994
            26327985 25757980 25347992

Nearby

Mesoscale Discussions in Florida, 2021Every mesoscale discussion in 2021

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.