Alert archive / Florida / Mesoscale Discussions in 2016

Mesoscale Discussion 25

January 17, 201630 counties in Florida

The Storm Prediction Center issued this mesoscale discussion at Jan 17, 2016, 2:31 AM EST for 30 counties in Florida. It was in force for 89 min.

The area

The outline as issued.

The facts

Issued
Jan 17, 2016, 2:31 AM EST (07:31 UTC)
Expired
Jan 17, 2016, 4:00 AM EST
In force
89 min
Issued by
the Storm Prediction Center
All 30 counties

Brevard County, FL, Broward County, FL, Charlotte County, FL, Citrus County, FL, Collier County, FL, DeSoto County, FL, Glades County, FL, Hardee County, FL, Hendry County, FL, Hernando County, FL, Highlands County, FL, Hillsborough County, FL, Indian River County, FL, Lake County, FL, Lee County, FL, Manatee 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, Pasco County, FL, Pinellas County, FL, Polk County, FL, Saint Lucie County, FL, Sarasota County, FL, Seminole County, FL, Sumter County, FL

The radar

The Tampa radar (KTBW), 83 km from the middle of the area, began a volume at 07:31 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

Tampa Bay, FL (KTBW), launched 00:00Z, 7.5 hours before the alert went out and 83 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.

581 
ACUS11 KWNS 170732
SWOMCD
SPC MCD 170731 
FLZ000-170900-

MESOSCALE DISCUSSION 0025
NWS STORM PREDICTION CENTER NORMAN OK
0131 AM CST SUN JAN 17 2016

AREAS AFFECTED...CENTRAL AND SOUTHERN FL PENINSULA

CONCERNING...TORNADO WATCH 4...

VALID 170731Z - 170900Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 4 CONTINUES.

SUMMARY...THE TORNADO THREAT IS INCREASING ALONG PARTS OF THE
WEST-CENTRAL AND SOUTHWESTERN FL COAST. EXPECT THE GREATEST TORNADO
POTENTIAL TO EXIST IN THIS AREA THROUGH AROUND 10-11Z.

DISCUSSION...THE TORNADO THREAT WILL INCREASE THROUGH AROUND 10Z
FROM NEAR TBW SOUTHWARD TO THE WESTERN KEYS AS CELLS AHEAD OF THE
MAIN LINE OF THUNDERSTORMS MOVE ONSHORE. A 06Z RAOB FROM TBW SHOWED
A VERY FAVORABLE LOW LEVEL HODOGRAPH SUPPORTIVE OF ORGANIZED
LOW-LEVEL ROTATION. HOWEVER...THE BOUNDARY LAYER REMAINS SOMEWHAT
STABLE ALONG THE WEST-CENTRAL COAST WHERE TEMPERATURES ARE COOLER
AND DEWPOINTS RANGE FROM THE UPPER 50S TO NEAR 60F. FURTHER SOUTH
TOWARD VNC...DEWPOINTS ARE IN THE MID TO UPPER 60S AND MUCAPE IS
NEAR 500 J/KG. SOME WARMING AND MOISTENING OF THE BOUNDARY LAYER IS
STILL POSSIBLE OVER THE NEXT COUPLE OF HOURS...BUT EXPECT THE
GREATEST NEAR-TERM TORNADO THREAT TO EXIST FROM NEAR/JUST SOUTH OF
TBW TO THE WESTERN KEYS. IN FACT...A SUPERCELL OFFSHORE FROM
SARASOTA COUNTY HAS BEEN SHOWING MODERATE TO STRONG LOW/MIDLEVEL
ROTATION THE LAST HOUR OR SO...INDICATING WHERE BETTER
THERMODYNAMICS ARE FAVORABLY ALIGNED WITH STRONG SHEAR PARAMETERS.

..LEITMAN.. 01/17/2016

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

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

LAT...LON   29068334 29038050 24387955 24388227 29068334

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, 5:08 AM ESTMesoscale DiscussionSPCBrevard, Broward, Charlotte, Collier, DeSoto, Glades and 15 more2 hr
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.