Severe Storm Outlook Narrative (AC)
Issued by NWS

Current Version | Previous Version | Text Only | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

000
ACUS11 KWNS 190957
SWOMCD
SPC MCD 190956
FLZ000-191200-

MESOSCALE DISCUSSION 0370
NWS STORM PREDICTION CENTER NORMAN OK
0456 AM CDT SAT APR 19 2014

AREAS AFFECTED...PORTIONS S FL.

CONCERNING...TORNADO WATCH 84...

VALID 190956Z - 191200Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 84 CONTINUES.

SUMMARY...LOOSELY ORGANIZED BAND OF STG AND POTENTIALLY SVR TSTMS IS
MOVING EWD ACROSS S FL -- GENERALLY S OF LAKE OKEECHOBEE AND OVER
RURAL/EVERGLADES AREAS.  THIS ACTIVITY WILL POSE SPORADIC SVR THREAT
AS IT CROSSES REMAINDER S FL THROUGH MIDMORNING.  MORE ISOLATED STG
CELLS WILL PROCEED EWD OVER ST LUCIE/INDIAN RIVER COUNTIES...PART OF
OTHERWISE WEAKENING CONVECTIVE BAND EXTENDING SWWD BEHIND MAIN TSTM
CORRIDOR.

DISCUSSION...MAIN BAND OF TSTMS IS MOVING EWD 20-25 KT INTO WRN
FRINGES PALM BEACH/BROWARD/MIAMI-DADE COUNTIES AND WILL CROSS
METRO/I-95 CORRIDOR DURING NEXT 2-3 HOURS...WHILE ADDITIONAL
CONVECTION MOVES/BUILDS NEWD ACROSS PORTIONS MIA/FLL METRO AREA.
OCNL BOW/LEWP FEATURES WITH ENHANCED OUTFLOW POOLS HAVE BEEN
DETECTED VIA MFL/88D AND MIA TDWR IN WESTERN CONVECTION...AND
ADDITIONAL DOWNDRAFT SURGES RELATED TO PRECIP LOADING MAY OCCUR THAT
ARE CAPABLE OF LOCALIZED WIND DAMAGE.  BOOKEND MESOVORTICES -- OF
WHICH A FEW WEAK SPECIMENS ALREADY HAVE BEEN INDICATED FROM SRN LAKE
OKEECHOBEE SWWD -- AND LEADING-EDGE QLCS CIRCULATIONS ALSO ARE
POSSIBLE AND APPEAR TO CONSTITUTE BULK OF MRGL TORNADO THREAT FROM
HERE ON.

SFC DEW POINTS 70S F AND WEAK CINH SUPPORT ESSENTIALLY UNINHIBITED
PRECONVECTIVE MLCAPE AROUND 1500 J/KG.  AS SUCH...MORE DEVELOPMENT
MAY OCCUR AHEAD OF MAIN BAND.  40-50 KT EFFECTIVE SHEAR MAGNITUDES
AND OBSERVED/LOCALIZED BACKING/CONVERGENCE OF FLOW ALONG IMMEDIATE E
COAST SUGGEST SUPERCELL THREAT IS NOT YET OVER.  SUPERCELLS
THEREFORE ARE STILL POSSIBLE...BUT APPEAR TO BE GETTING LESS LIKELY
WITH TIME PAST SUNRISE AS TWO FACTORS PLAY IN...
1. PREDOMINANCE OF MESSY/QUASI-LINEAR CONVECTIVE MODES AND
2. FCST VEERING OF BOUNDARY-LAYER FLOW AND RESULTANT GRADUAL
REDUCTION IN LOW-LEVEL SHEAR...TRENDS ALREADY SEEN IN INLAND SFC OBS
AND VWP AS MAIN SFC LOW CROSSES NRN FL.

..EDWARDS.. 04/19/2014

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

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

LAT...LON   26218088 26998068 27868045 27218019 26808000 25648014
            25688019 25648026 25448030 25418026 25528018 25188031
            25118073 25118112 25278117 25338111 25408112 25588121
            26218088




USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.