Alert archive / Florida / Mesoscale Discussions in 2012
Mesoscale Discussion 1815
The Storm Prediction Center issued this mesoscale discussion at Aug 26, 2012, 12:58 PM EDT for 12 counties in Florida. It was in force for 2 hr.
The area
The outline as issued.
The facts
- Issued
- Aug 26, 2012, 12:58 PM EDT (16:58 UTC)
- Expired
- Aug 26, 2012, 3:00 PM EDT
- In force
- 2 hr
- Issued by
- the Storm Prediction Center
Counties Broward County, FL, Collier County, FL, Glades County, FL, Hendry County, FL, Highlands County, FL, Lee County, FL, Martin County, FL, Miami-Dade County, FL, Monroe County, FL, Okeechobee County, FL, Palm Beach County, FL, Saint Lucie County, FL
The radar
The Miami radar (KAMX), 98 km from the middle of the area, began a volume at 16:59 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, 5.0 hours before the alert went out and 100 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.
- Mixed-layer CAPE
- 1782 J/kg
- Mixed-layer CIN
- -7 J/kg
- Mixed-layer LCL
- 619 m above ground
- 0-6 km bulk shear
- 32 kt
- 0-1 km storm-relative helicity
- 204 m²/s²
- 0-3 km storm-relative helicity
- 224 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 6.1
The text
As transmitted, in the capitals the NWS used until 2016.
736
ACUS11 KWNS 261659
SWOMCD
SPC MCD 261658
FLZ000-261900-
MESOSCALE DISCUSSION 1815
NWS STORM PREDICTION CENTER NORMAN OK
1158 AM CDT SUN AUG 26 2012
AREAS AFFECTED...PORTIONS SRN FL AND KEYS
CONCERNING...TORNADO WATCH 589...
VALID 261658Z - 261900Z
THE SEVERE WEATHER THREAT FOR TORNADO WATCH 589 CONTINUES.
SUMMARY...POTENTIAL FOR ISOLATED TORNADOES WILL PERSIST INTO THE
AFTERNOON OVER S FL...BUT GREATEST THREAT IS EXPECTED TO EVOLVE OVER
THE SRN TIP OF THE PENINSULA THIS AFTERNOON.
DISCUSSION...AT 11 AM EDT THIS MORNING THE CENTER OF TS ISAAC WAS
LOCATED 180 KM SE OF KEY WEST MOVING WNW AT 15 KT. SEE LATEST
DISCUSSIONS FROM NHC FOR MORE INFORMATION. LATEST VISIBLE IMAGERY
SHOWS WIDESPREAD CLOUDS AND RAIN ASSOCIATED WITH THE OUTER
CONVECTIVE BANDS HAVE OVERSPREAD THE SRN HALF OF THE FL
PENINSULA...EFFECTIVELY LIMITING DESTABILIZATION.
MOREOVER...CONVECTIVE MODES HAVE BEEN PREDOMINANTLY LINEAR. THESE
FACTORS HAVE SO FAR SERVED TO LIMIT A MORE ROBUST TORNADO THREAT.
HOWEVER...AN AREA OF CLEARING EAST OF THE CENTER SHOULD EXPAND NWD
INTO THE SRN TIP OF FL THIS AFTERNOON WHERE LOW LEVEL HODOGRAPHS ARE
MAXIMIZED WITH 200-400 M2/S2 STORM RELATIVE HELICITY IN THE 0-1 KM
LAYER. ADDITIONAL CONVECTION MAY DEVELOP ALONG CONVERGENCE BANDS
WITHIN THIS ZONE OF BOUNDARY LAYER DESTABILIZATION THIS
AFTERNOON...LIKELY INCREASING THE THREAT FOR EMBEDDED SUPERCELLS AND
ISOLATED TORNADOES.
..DIAL.. 08/26/2012
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...MFL...MLB...KEY...TBW...
LAT...LON 26048170 26748216 27548139 27658031 25798017 24948068
24608176 25368136 26048170SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 26, 7:05 AM EDT | Mesoscale Discussion | SPC | Broward, Charlotte, Collier, Glades, Hendry, Lee and 4 more | 2 hr |
| Aug 26, 8:29 AM EDT | Tornado Watch | SPC | Broward, Charlotte, Collier, DeSoto, Glades, Hendry and 9 more | 9 hr |
| Aug 26, 4:28 PM EDT | Mesoscale Discussion | SPC | Broward, Collier, Glades, Hendry, Martin, Miami-Dade and 2 more | 62 min |
Nearby
Mesoscale Discussions in Florida, 2012Every mesoscale discussion in 2012
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.