Alert archive / Florida / Mesoscale Discussions in 2011
Mesoscale Discussion 27
The Storm Prediction Center issued this mesoscale discussion at Jan 17, 2011, 6:27 PM EST for Miami-Dade County, Florida. It was in force for 63 min.
The area
The outline as issued.
The facts
- Issued
- Jan 17, 2011, 6:27 PM EST (23:27 UTC)
- Expired
- Jan 17, 2011, 7:30 PM EST
- In force
- 63 min
- Issued by
- the Storm Prediction Center
County Miami-Dade County, FL
The radar
The Miami radar (KAMX), 41 km from the middle of the area, began a volume at 23:30 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, 11.5 hours before the alert went out and 67 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
- 44 J/kg
- Mixed-layer CIN
- -136 J/kg
- Mixed-layer LCL
- 894 m above ground
- 0-6 km bulk shear
- 50 kt
- 0-1 km storm-relative helicity
- 148 m²/s²
- 0-3 km storm-relative helicity
- 213 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.3
The text
As transmitted, in the capitals the NWS used until 2016.
150
ACUS11 KWNS 172327
SWOMCD
SPC MCD 172327
FLZ000-180030-
MESOSCALE DISCUSSION 0027
NWS STORM PREDICTION CENTER NORMAN OK
0527 PM CST MON JAN 17 2011
AREAS AFFECTED...PORTIONS EXTREME SERN FL AND UPPER KEYS.
CONCERNING...TORNADO WATCH 5...
VALID 172327Z - 180030Z
THE SEVERE WEATHER THREAT FOR TORNADO WATCH 5 CONTINUES.
LINE OF MAINLY SUB-SVR TSTMS...WITH POTENTIAL FOR ISOLATED SVR GUST
OR QLCS TORNADO...IS FCST TO CONTINUE MOVING EWD ACROSS REMAINDER
UPPER KEYS AND SRN/ERN PORTIONS MIAMI-DADE COUNTY THROUGH AROUND
0015Z. WW 5 IS SCHEDULED TO EXPIRE AT 00Z...BUT MAY NEED TO BE
EXTENDED LOCALLY IN TIME UNTIL ACTIVITY HAS CLEARED ELLIOTT KEY AND
ADJACENT WATERS. WW ALSO MAY BE REMOVED BEHIND PRIMARY BAND OF
CONVECTION IN MEANTIME.
SFC MESOANALYSIS SHOWS OUTFLOW BOUNDARY FROM EARLIER CONVECTION HAS
SETTLED QUASISTATIONARY FROM ABOUT 30 SE OF NORTH BIMINI TO ABOUT 10
SE OF ISLAMORADA...INTERSECTING CONVECTIVE BAND JUST E MTH. AIR MASS
GRADUALLY STABILIZES N OF THIS BOUNDARY...HOWEVER MODIFIED
RUC/ETA-KF SOUNDINGS SUGGEST THAT SFC-BASED EFFECTIVE LIFTED PARCELS
ARE PRESENT ACROSS MUCH OF FL BAY AND SRN MIAMI-DADE COUNTY AROUND
HST. PRE-STORM MLCAPE ESTIMATES DECREASE FROM AROUND 1000 J/KG OVER
UPPER KEYS TO LESS THEN 250 J/KG BETWEEN HST-MIA. BACKED FLOW N OF
BOUNDARY ENHANCED BOTH LOW-LEVEL AND DEEP-LAYER SHEAR...WITH AROUND
40 KT EFFECTIVE SHEAR MAGNITUDE ESTIMATED OVER REGION. VEERED FLOW
JUST ABOVE SFC HAS RESULTED IN MORE ELONGATED HODOGRAPHS AND
UNIDIRECTIONAL FLOW FROM UPPER BOUNDARY LAYER UPWARD...FAVORING
CONTINUED DOMINANCE OF QUASI-LINEAR CONVECTIVE STRUCTURES.
..EDWARDS.. 01/17/2011
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...MFL...KEY...
LAT...LON 24788084 25358070 25828073 25848011 25458017 25128037
24958056 24788084SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jan 17, 10:17 AM EST | Mesoscale Discussion | SPC | Brevard, Broward, Charlotte, Collier, DeSoto, Glades and 15 more | 118 min |
| Jan 17, 11:33 AM EST | Tornado Watch | SPC | Broward, Miami-Dade, Monroe, Palm Beach | 7 hr |
| Jan 17, 11:54 AM EST | Tornado Watch | SPC | Brevard, Charlotte, DeSoto, Hardee, Highlands, Indian River and 9 more | 5 hr |
| Jan 17, 3:23 PM EST | Mesoscale Discussion | SPC | Broward, Miami-Dade, Monroe | 97 min |
Nearby
Mesoscale Discussions in Florida, 2011Every 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.