Alert archive / Florida / Mesoscale Discussions in 2011

Mesoscale Discussion 46

January 25, 2011Broward County, Miami-Dade County, Palm Beach County, Florida

The Storm Prediction Center issued this mesoscale discussion at Jan 25, 2011, 9:51 PM EST for Broward County, Miami-Dade County, Palm Beach County, Florida. It was in force for 54 min.

The area

The outline as issued.

The facts

Issued: Jan 25, 2011, 9:51 PM EST (02:51 UTC)
Expired: Jan 25, 2011, 10:45 PM EST
In force: 54 min
Issued by: the Storm Prediction Center

Counties Broward County, FL, Miami-Dade County, FL, Palm Beach County, FL

The radar

The Miami radar (KAMX), 81 km from the middle of the area, began a volume at 02:55 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, 2.9 hours before the alert went out and 58 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: 1046 J/kg
Mixed-layer CIN: -1 J/kg
Mixed-layer LCL: 569 m above ground
0-6 km bulk shear: 46 kt
0-1 km storm-relative helicity: 201 m²/s²
0-3 km storm-relative helicity: 276 m²/s²
Significant tornado parameter: 1.3
Supercell composite: 8.2

Open this sounding in Storm Lab

The text

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

399 
ACUS11 KWNS 260251
SWOMCD
SPC MCD 260251 
FLZ000-260345-

MESOSCALE DISCUSSION 0046
NWS STORM PREDICTION CENTER NORMAN OK
0851 PM CST TUE JAN 25 2011

AREAS AFFECTED...SRN FL

CONCERNING...TORNADO WATCH 8...

VALID 260251Z - 260345Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 8 CONTINUES.

LOW-AMPLITUDE IMPULSE...EJECTING AHEAD OF THE DEEPER TROUGH OVER THE
NRN GULF OF MEXICO/LOWER MS VLY...AIDED IN THE
INTENSIFICATION/MAINTENANCE OF THE QLCS ACROSS NRN/CNTRL FL TODAY. 
REMAINING LINE OF STORMS WILL CONTINUE ESE ACROSS THE REMAINDER OF
SRN FL THROUGH 06Z.

CORE OF THE STRONGEST LLJ WAS BEGINNING TO MOVE NEWD WITH A VEERING
LOW-LEVEL WIND PROFILE NOTED ACROSS SRN FL/KEYS RECENTLY.  THIS IS
RESULTING IN A RELAXATION OF THE 0-1KM SHEAR AND REDUCING THE
TORNADO THREAT.  FURTHERMORE...SHIELD OF TRAILING STRATIFORM RAIN
100-150 NM POLEWARD OF THE LINEAR MCS IS CONTRIBUTING TO AN
ACCELERATING COLD POOL.  THIS IS MAKING IT DIFFICULT FOR LONG-LIVED
MESOSCALE LINE SEGMENTS TO EXIST...WHICH WOULD OTHERWISE BE
FAVORABLE FOR SWATHS OF WIND DAMAGE.  AS SUCH...EXPECTATION IS FOR
ISOLATED DAMAGING WINDS...GENERALLY N OF ALLIGATOR ALLEY AND INTO
METRO BROWARD/PALM BEACH COUNTIES BEFORE 04Z.

..RACY.. 01/26/2011

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

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

LAT...LON   25907979 25578057 25798110 26308120 26838063 27218000
            27227967 25907979

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jan 25, 7:20 PM EST	Mesoscale Discussion	SPC	Brevard, Charlotte, Collier, DeSoto, Glades, Hendry and 7 more	55 min
Jan 25, 8:03 PM EST	Tornado Watch	SPC	Broward, Collier, Glades, Hendry, Indian River, Martin and 3 more	4 hr

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.