Alert archive / Florida / Mesoscale Discussions in 2016

Mesoscale Discussion 26

January 17, 201621 counties in Florida

The Storm Prediction Center issued this mesoscale discussion at Jan 17, 2016, 5:08 AM EST for 21 counties in Florida. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued
Jan 17, 2016, 5:08 AM EST (10:08 UTC)
Expired
Jan 17, 2016, 7:15 AM EST
In force
2 hr
Issued by
the Storm Prediction Center
All 21 counties

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

The radar

The Tampa radar (KTBW), 145 km from the middle of the area, began a volume at 10:08 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

Tampa Bay, FL (KTBW), launched 00:00Z, 10.1 hours before the alert went out and 145 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, Tampa Bay, FL at 00:00Z on 2016-01-17Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1 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, Tampa Bay, FL at 00:00Z on 2016-01-17The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 12 square meters per square second.1939587897117136Sfc1 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
1 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1407 m above ground
0-6 km bulk shear
64 kt
0-1 km storm-relative helicity
12 m²/s²
0-3 km storm-relative helicity
106 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

778 
ACUS11 KWNS 171008
SWOMCD
SPC MCD 171008 
FLZ000-171215-

MESOSCALE DISCUSSION 0026
NWS STORM PREDICTION CENTER NORMAN OK
0408 AM CST SUN JAN 17 2016

AREAS AFFECTED...PORTIONS OF CENTRAL AND SOUTHERN FL

CONCERNING...TORNADO WATCH 4...

VALID 171008Z - 171215Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 4 CONTINUES.

SUMMARY...DAMAGING WINDS AND A FEW TORNADOES WILL BE POSSIBLE ACROSS
SOUTHERN FL THE NEXT FEW HOURS AS A LINE OF THUNDERSTORMS MOVES
ONSHORE THE SOUTHWESTERN FL COAST/WESTERN KEYS.

DISCUSSION...THE NEAR-TERM TORNADO THREAT WILL BE GREATEST ACROSS
SOUTHWESTERN FL AND THE WESTERN FL KEYS THE NEXT FEW HOURS AS THE
MAIN LINE OF THUNDERSTORMS MOVES ONSHORE. WHILE STORMS EARLIER WERE
MAINLY SEMI-DISCRETE...CONVECTIVE MODE HAS NOW SHIFTED TOWARD BOWING
LINE SEGMENTS WITH EMBEDDED MESOVORTICES...A FEW OF WHICH HAVE BEEN
NOTED OFFSHORE COLLIER COUNTY. THE LATEST VWP FROM BYX AND AMX
CONTINUE TO SHOW STRONG SPEED SHEAR...BUT WINDS IN THE LOWEST 1 KM
HAVE VEERED MORE TOWARD THE S/SW...AND SOME ADDITIONAL VEERING IS
EXPECTED INTO THE MORNING HOURS. SURFACE DEWPOINTS IN THE MID UPPER
60S TO NEAR 70 F HAVE RESULTED IN BETTER INSTABILITY THAN FURTHER
NORTH...WITH MLCAPE BETWEEN 500-1000 J/KG. GIVEN CONVECTIVE MODE AND
EVOLVING SHEAR PROFILES...DAMAGING WINDS AND A FEW MESOVORTEX
TORNADOES STILL WILL BE POSSIBLE THE FEW HOURS...ESPECIALLY ACROSS
SOUTH FL.

..LEITMAN.. 01/17/2016

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

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

LAT...LON   25578250 26948207 28388161 28958137 28998048 24377954
            24398225 25578250

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jan 16, 11:03 PM ESTMesoscale DiscussionSPCCharlotte, Collier, DeSoto, Glades, Hardee, Hendry and 7 more117 min
Jan 17, 12:47 AM ESTTornado WatchSPCBrevard, Broward, Charlotte, Citrus, Collier, DeSoto and 25 more8 hr
Jan 17, 2:31 AM ESTMesoscale DiscussionSPCBrevard, Broward, Charlotte, Citrus, Collier, DeSoto and 24 more89 min
Jan 17, 6:38 AM ESTMesoscale DiscussionSPCBroward, Miami-Dade, Monroe, Palm Beach97 min

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.