DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN - TopicsExpress

DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1230 PM CDT SUN JUL 20 2014 VALID 211200Z - 221200Z ...THERE IS A MDT RISK OF SVR TSTMS FOR FAR SERN ND...NERN SD...MUCH OF CENTRAL AND SRN MN...AND PART OF WEST CENTRAL/NWRN WI... ...THERE IS A SLGT RISK OF SVR TSTMS SURROUNDING THE MDT RISK FROM THE DAKOTAS EWD THROUGH THE UPPER MIDWEST... ...SUMMARY... SEVERE STORMS APPEAR INCREASINGLY LIKELY ACROSS PARTS OF THE UPPER MIDWEST FROM MONDAY LATE AFTERNOON INTO TUESDAY MORNING. DAMAGING WINDS...SOME WITH SPEEDS TO HURRICANE-FORCE...SHOULD BE THE PRIMARY HAZARD. HOWEVER...A TORNADO THREAT AND LARGE HAIL CANNOT BE RULED OUT. ...UPPER MIDWEST... GIVEN THE DEGREE OF INSTABILITY EXPECTED ACROSS PARTS OF THE ERN DAKOTAS EWD TO WRN WI MONDAY AFTERNOON/EVENING /MLCAPE EXCEEDING 4000 J PER KG/ AND THE MODEL AGREEMENT IN TIMING OF THE GREAT BASIN SHORTWAVE TROUGH...CONFIDENCE CONTINUES TO INCREASE FOR THE POTENTIAL OF A FORWARD-PROPAGATING MCS FROM MONDAY EVENING TO EARLY TUESDAY MORNING. SEVERE WIND GUSTS...SOME AT HURRICANE-FORCE...WILL BE POSSIBLE ACROSS NERN SD...SERN ND...MUCH OF CENTRAL AND SRN MN INTO WRN WI RESULTING IN AN UPGRADE TO A MODERATE RISK FOR THIS REGION. THE THERMODYNAMIC SETUP REMAINS SIMILAR TO THE INITIAL DAY 2 ISSUANCE...WITH CONTINUED EVAPOTRANSPIRATION AND POLEWARD MOISTURE TRANSPORT YIELDING INCREASINGLY RICH BOUNDARY LAYER MOISTURE BENEATH AN EML CAPPING INVERSION ACROSS ERN SD INTO CNTRL/SRN MN. SURFACE DEW POINTS WILL REACH INTO THE 70S AS MEAN MIXING RATIOS APPROACH 18-20 G/KG. WITH VERY STEEP MID-LEVEL LAPSE RATES AROUND 7.5-9.0 DEG C/KM IN THE 700-500 MB LAYER...AN EXTREMELY UNSTABLE AIR MASS SHOULD DEVELOP. LARGE-SCALE ASCENT ATTENDANT TO THE PROGRESSIVE SHORTWAVE TROUGH WILL MOVE INTO ND/NRN SD MONDAY AFTERNOON. THIS ASCENT COMBINED WITH ISENTROPIC LIFT SHOULD RESULT IN A MIX OF SCATTERED ELEVATED AND SURFACE-BASED STORMS BY MID-LATE AFTERNOON. ALTHOUGH STRONGER MID-LEVEL WLYS WILL BE CONFINED TO THE CANADIAN PRAIRIES... SUFFICIENT DEEP-LAYER SHEAR WILL EXIST FOR MULTICELLS/TRANSIENT SUPERCELLS SUPPORTING ALL SEVERE HAZARDS WITH THE INITIAL STORMS. A CONTINUED LIKELIHOOD EXISTS FOR MLCIN BEING MINIMIZED NEAR THE SURFACE CYCLONE AND ADJACENT WARM SECTOR WHERE SURFACE TEMPERATURES SHOULD REACH AT LEAST THE UPPER 90S. THUS...AN AMALGAMATION OF UPDRAFTS SHOULD YIELD A DEEPENING COLD POOL...WITH AN UPSCALE GROWTH INTO AN MCS --- PRODUCING SVR WIND GUSTS --- APPEARING TO BE MORE LIKELY THE ERN DAKOTAS INTO MN AND WRN WI THROUGH MONDAY NIGHT/EARLY TUESDAY MORNING.