Alert archive / Florida / Mesoscale Discussions in 2016

Mesoscale Discussion 64

January 28, 2016Miami-Dade County, Monroe County, Florida

The Storm Prediction Center issued this mesoscale discussion at Jan 28, 2016, 6:22 AM EST for Miami-Dade County, Monroe County, Florida. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued
Jan 28, 2016, 6:22 AM EST (11:22 UTC)
Expired
Jan 28, 2016, 8:45 AM EST
In force
2 hr
Issued by
the Storm Prediction Center
Chance of a watch
20%

Counties Miami-Dade County, FL, Monroe County, FL

The radar

The Key West radar (KBYX), 84 km from the middle of the area, began a volume at 11:21 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

Key West, FL (KEYW), launched 00:00Z, 11.4 hours before the alert went out and 89 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, Key West, FL at 00:00Z on 2016-01-28Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1029 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, Key West, FL at 00:00Z on 2016-01-28The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 108 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
1029 J/kg
Mixed-layer CIN
-14 J/kg
Mixed-layer LCL
737 m above ground
0-6 km bulk shear
53 kt
0-1 km storm-relative helicity
108 m²/s²
0-3 km storm-relative helicity
114 m²/s²
Significant tornado parameter
0.7
Supercell composite
3.1

Open this sounding in Storm Lab

The text

As transmitted.

134 
ACUS11 KWNS 281123
SWOMCD
SPC MCD 281122 
FLZ000-281345-

MESOSCALE DISCUSSION 0064
NWS STORM PREDICTION CENTER NORMAN OK
0522 AM CST THU JAN 28 2016

AREAS AFFECTED...SOUTH FL/FL KEYS

CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY 

VALID 281122Z - 281345Z

PROBABILITY OF WATCH ISSUANCE...20 PERCENT

SUMMARY...A COUPLE OF STRONGER STORMS MAY GRADUALLY MOVE INLAND
ACROSS THE SOUTHERN FL PENINSULA AND/OR MOVE SLOWLY ACROSS PARTS OF
THE KEYS THROUGH THE EARLY/MID-MORNING HOURS. SOME RISK EXISTS FOR
WATERSPOUTS AND LOCALLY DAMAGING WINDS/BRIEF TORNADO INLAND.

DISCUSSION...AS OF 615 AM EST/1115Z...A NORTHEAST/SOUTHWEST-ORIENTED
CLUSTER OF STORMS CONTINUES TO MOVE EAST-NORTHEASTWARD TOWARD
COLLIER COUNTY/MAINLAND MONROE AND THE LOWER KEYS...WITH A FEW
LINE-PRECEDING SHOWERS ALSO NOTED ACROSS SOUTHERN MAINLAND MONROE
AND NEAR KEY WEST. AS A BYPRODUCT OF CONVECTION LAST EVENING...AN
EFFECTIVE BOUNDARY ARCS ACROSS THE KEYS/NEAR THE SOUTHERN TIP OF THE
PENINSULA. RELATED TO THE INFLUENCE OF THIS BOUNDARY/PRIOR
CONVECTION...SURFACE TEMPERATURES ACROSS THE SOUTHERN FL PENINSULA
ARE AROUND 2-4 DEG F COOLER THAN THIS TIME YESTERDAY...WHILE
LOW-LEVEL SHEAR APPEARS SLIGHTLY WEAKER...PARTICULARLY AT MIAMI AS
PER LATEST WSR-88D VWP DATA. THAT SAID...LOW-LEVEL SHEAR/SRH SHOULD
GRADUALLY INCREASE INTO THE MID-MORNING HOURS IN TANDEM WITH SOME
MODIFICATION/NORTHWARD SHIFT OF THIS EFFECTIVE BOUNDARY. THIS COULD
BETTER SUPPORT SUSTAINED BOWING SEGMENTS AND AT LEAST
TRANSIENT/EMBEDDED UPDRAFT ROTATION AS THE MORNING WEARS ON. SOME
RISK EXISTS FOR WATERSPOUTS AND LOCALLY DAMAGING WINDS/BRIEF TORNADO
INLAND...PARTICULARLY IN AREAS NEAR/IMMEDIATELY NORTH OF THE
BOUNDARY.

..GUYER/EDWARDS.. 01/28/2016

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

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

LAT...LON   25368192 25868158 26218088 26068003 25178012 24468115
            24398232 24918278 25368192

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jan 28, 8:53 AM ESTMesoscale DiscussionSPCBroward, Miami-Dade, Monroe2 hr

Nearby

Mesoscale Discussions in Florida, 2016Every mesoscale discussion in 2016

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.