Day 4-8 Outlook
DAY 4-8 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0347 AM CDT SUN JUL 26 2015 VALID 291200Z - 031200Z ...DISCUSSION... UPPER LEVEL HIGH PRESSURE WILL EXTEND FROM THE SOUTHERN PLAINS WESTWARD ACROSS THE SOUTHWEST U.S. FOR MUCH OF THE DAY 4-8 PERIOD. AN UPPER LEVEL LOW NEAR THE MINNESOTA/ONTARIO BORDER WILL LIFT NORTHWARD WEDNESDAY/THURSDAY AND STRONGER MID-LEVEL WIND FIELDS WILL ALSO TEMPORARILY SHIFT NORTH INTO CANADA. A SURFACE COLD FRONT WILL MOVE EAST ACROSS THE GREAT LAKES/OHIO VALLEY REGION WEDNESDAY AND NEW ENGLAND ON THURSDAY...LIKELY ACCOMPANIED BY AT LEAST SCATTERED THUNDERSTORMS. AN ISOLATED SEVERE THREAT IS POSSIBLE WEDNESDAY/THURSDAY GIVEN DEW POINTS THAT WILL LIKELY BE IN THE UPPER 60S/LOWER 70S RESULTING IN MODERATE SURFACE-BASED INSTABILITY. HOWEVER...DEEP SHEAR IS FORECAST TO BE AT OR BELOW 25 KTS WHICH SHOULD TEMPER THE OVERALL RISK. ELSEWHERE...LOW-LEVEL MOISTURE WILL QUICKLY RETURN THROUGH THE CENTRAL/NORTHERN PLAINS IN THE WAKE OF THE FRONTAL PASSAGE EARLY IN THE WEEK AS AN ELEVATED MIXED LAYER BECOMES RE-ESTABLISHED FROM THE NORTHERN ROCKIES EAST INTO THE CENTRAL/NORTHERN PLAINS. THE SEVERE RISK MAY INCREASE TOWARDS THE END OF THE WEEK ACROSS THE NORTHERN ROCKIES INTO THE UPPER MIDWEST WHERE MODERATELY STRONG WEST-NORTHWEST UPPER-LEVEL FLOW WILL EXIST. WHILE PREDICTABILITY IS CURRENTLY TOO LOW TO ASSIGN 15 PERCENT DAILY RISK AREAS...LATER OUTLOOKS MAY CONTAIN AT LEAST MARGINAL RISK AREAS/5 PERCENT PROBABILITIES FOR THESE SCENARIOS.
from SPC Convective Outlooks http://1.usa.gov/1Jndrlm
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