ZCZC SPCSWOMCD ALL ACUS11 KWNS 250239 SPC MCD 250239 OKZ000-250445- MESOSCALE DISCUSSION 0718 NWS STORM PREDICTION CENTER NORMAN OK 0939 PM CDT TUE MAY 24 2016 AREAS AFFECTED...CENTRAL...NORTH-CENTRAL AND NORTHEAST OK CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY VALID 250239Z - 250445Z PROBABILITY OF WATCH ISSUANCE...20 PERCENT SUMMARY...ISOLATED LARGE HAIL WILL BE POSSIBLE WITH THE STRONGEST SUSTAINED STORMS ACROSS PORTIONS OF CENTRAL INTO NORTHEAST OK THROUGH LATE EVENING AND EARLY OVERNIGHT. CURRENT THINKING SUGGESTS SEVERE-WEATHER COVERAGE SHOULD REMAIN TOO LIMITED TO SUPPORT WATCH ISSUANCE. DISCUSSION...MID-EVENING SURFACE ANALYSIS AND MOSAIC RADAR IMAGERY SHOWED AN OUTFLOW BOUNDARY ATTENDANT TO THE NORTHEAST/EAST-CENTRAL OK MCS EXTENDED FROM SOUTH OF FSM WESTWARD INTO NORTHEAST HUGHES COUNTY AND THEN NORTHWESTWARD THROUGH SOUTHERN LINCOLN TO ALFALFA COUNTIES. GIVEN COOLING OF SURFACE TEMPERATURES ACROSS CENTRAL OK...MODIFIED 00Z OUN SOUNDING SUGGESTS THE RECENT STORM DEVELOPMENT ACROSS THE CENTRAL OK COUNTIES OF OKLAHOMA...CLEVELAND...AND POTTAWATOMIE IS LIKELY ELEVATED. THE PRESENCE OF STEEP MIDLEVEL LAPSE RATES /9 C/KM PER THE 00Z OUN SOUNDING/ COMBINED WITH A STRENGTHENING SOUTHERLY LLJ MAINTAINING AN INFLOW OF MODERATELY STRONG INSTABILITY /2000-3000 J PER KG/ AND EFFECTIVE BULK SHEAR OF 40-45 KT FAVORS LARGE HAIL AS THE PRIMARY THREAT. THIS ENVIRONMENT IS VERY SUPPORTIVE FOR RAPID STORM INTENSIFICATION AS DEPICTED BY THE TRENDS IN RADAR IMAGERY AND STRONG COOLING CLOUD TOPS WITH THE INITIAL ELEVATED STORMS. AS THE CURRENT STORMS MOVE TO THE NORTHEAST...THEY WILL TRACK NORTH OF THE AFOREMENTIONED CONVECTIVE OUTFLOW BOUNDARY /ABOVE A MORE STABLE BOUNDARY LAYER WITH NORTHEAST EXTENT/. ..PETERS/EDWARDS.. 05/25/2016 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...TSA...OUN... LAT...LON 34549649 35549761 36099801 36559802 36749759 36939703 36679620 36269589 35949577 35559560 35099559 34539620 34549649 NNNN