NORMAN OK 0310 PM CDT SAT JUN 20 2015
AREAS AFFECTED...CENTRAL/SOUTHERN IOWA...FAR NORTHERN MISSOURI...AND FAR WESTERN ILLINOIS
CONCERNING...SEVERE POTENTIAL...WATCH LIKELY VALID 202010Z - 202215Z
PROBABILITY OF WATCH ISSUANCE...80 PERCENT
SUMMARY...ELEVATED CONVECTION CONTINUES OVER EASTERN IOWA...WITH ADDITIONAL CONVECTION LIKELY TO DEVELOP ACROSS A COLD FRONT IN CENTRAL IOWA. WITH INCREASING DESTABILIZATION AND CONVECTIVE DEVELOPMENT APPEARING LIKELY TO OCCUR...A TORNADO WATCH WILL BE ISSUED BY 21Z. DISCUSSION...ELEVATED CONVECTION HAS PERSISTED ACROSS EASTERN IOWA THROUGHOUT THE DAY...PRODUCING SPORADIC INSTANCES OF MARGINALLY SEVERE HAIL AND SUB-SEVERE WIND GUSTS. TO THE WEST OF THIS CONVECTION...STRONG CAPPING AND STRONG INSOLATION HAS ALLOWED FOR A STRONGLY UNSTABLE ENVIRONMENT TO DEVELOP WITH 3000-4000 J/KG MLCAPE. VEERED SURFACE FLOW IN WESTERN PARTS OF THE DISCUSSION AREA HAVE LESSENED THE MAGNITUDE OF LOW-LEVEL SHEAR...BUT 0-3KM STORM RELATIVE HELICITY VALUES AROUND 250 M2/S2 INDICATED ON LATEST WSR-88D WIND PROFILER AT DMX SUGGESTS THE ENVIRONMENT WILL HAVE SUFFICIENT SHEAR FOR STORM ROTATION AND A TORNADO THREAT IN SURFACE BASED STORMS. LATEST HIGH-RESOLUTION MODEL GUIDANCE CONTINUES TO SUGGEST AN INCREASE IN SURFACE-BASED CONVECTION ALONG SEWD MOVING COLD FRONT IN IOWA...AND DAMAGING WINDS...SIGNIFICANT HAIL...AND TORNADOES ARE ALL POSSIBLE AS CONVECTION MATERIALIZES. A TORNADO WATCH WILL LIKELY BE ISSUED BY 21Z. ..COOK/GUYER.. 06/20/2015
This watch is just outside our viewing area -- but remain alert this evening!
No comments:
Post a Comment