DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0800 PM CDT SUN AUG 07 2016 VALID 080100Z - 081200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PORTIONS OF WESTERN AND CENTRAL MT... ...THERE IS A MRGL RISK OF SVR TSTMS SURROUNDING THE SLGT RISK TO THE NORTHERN HIGH PLAINS AND SOUTH THROUGH WESTERN WY TO NORTHEAST UT... ...THERE IS A MRGL RISK OF SVR TSTMS ACROSS A SMALL PORTION OF THE SOUTHERN HIGH PLAINS... ...SUMMARY... SEVERE THUNDERSTORMS WITH ISOLATED DAMAGING WIND GUSTS WILL BE POSSIBLE OVER PORTIONS OF WESTERN AND NORTHERN MONTANA THROUGH THIS EVENING. SEPARATE AREAS WHERE STORMS MAY PRODUCE A FEW LOCALLY STRONG WIND GUSTS ARE ACROSS PARTS OF EASTERN MONTANA AND EASTERN WYOMING INTO THE FAR WESTERN DAKOTAS THIS EVENING...AND ACROSS FAR WESTERN WYOMING TO NORTHEAST UTAH. ...PARTS OF WESTERN AND CENTRAL MT... FORCING FOR ASCENT ATTENDANT TO A LEAD MIDLEVEL IMPULSE /LOCATED TO THE EAST OF THE WESTERN WA MIDLEVEL CLOSED LOW/ WILL CONTINUE TO CROSS WESTERN INTO CENTRAL MT THIS FORECAST PERIOD. THIS ASCENT COMBINED WITH STRONG BULK SHEAR ACCOMPANYING A 50-KT 500-MB JET SHOULD SUPPORT ADDITIONAL STRONG TO SEVERE STORMS SPREADING THROUGH CENTRAL MT TOWARD SOUTHERN SASKATCHEWAN AND SOUTHERN ALBERTA. FOR ADDITIONAL INFORMATION...REFER TO SPC MESOSCALE DISCUSSION 1497. GIVEN RECENT MODEL DATA...THE SLIGHT RISK AREA HAS BEEN EXPANDED A LITTLE ON ITS EAST AND NORTHWEST SIDES. ...EASTERN MT/EASTERN WY/FAR WESTERN DAKOTAS... REFERENCE SPC MESOSCALE DISCUSSION 1496 FOR DETAILS FOR THIS REGION. THIS OUTLOOK HAS EXPANDED THE MARGINAL RISK AREA INTO THE FAR WESTERN DAKOTAS AS ONGOING STORMS IN SOUTHEAST MT AND EASTERN WY ADVANCE THROUGH THE NORTHERN HIGH PLAINS...WHERE SUFFICIENT CAPE/SHEAR SUPPORT A POTENTIAL FOR A FEW ADDITIONAL SEVERE STORMS. ...OK PANHANDLE INTO NORTHERN OK AND ADJACENT SOUTHERN KS... A BOUNDARY EXTENDING EAST-WEST ACROSS NORTHERN OK TO THE VICINITY OF THE NORTHERN TX/OK PANHANDLES MAY MOVE A LITTLE NORTH THIS FORECAST PERIOD. RESIDUAL MODERATE TO STRONG INSTABILITY SHOULD PROVE SUFFICIENT FOR ADDITIONAL STORMS THROUGH THIS EVENING INTO THE OVERNIGHT FROM WEST TO EAST AS WEAK MIDLEVEL IMPULSES TRAVERSE THIS REGION...WITHIN A PLUME OF MOISTURE EXTENDING TO THE ENE FROM NM. AN INCREASE IN LOW-LEVEL WINDS ACROSS THE SOUTHERN PLAINS THROUGH TONIGHT WILL RESULT IN AN INCREASE IN LOW-LEVEL WAA TO FURTHER SUPPORT THE POTENTIAL FOR STORMS. MODEST BULK SHEAR AND THE AVAILABLE INSTABILITY SUGGEST THE STRONGEST STORMS WILL BE CAPABLE OF PRODUCING LOCALLY STRONG WINDS...THOUGH HAIL CANNOT BE RULED OUT. ...NORTHERN AND CENTRAL LA... A COMPOSITE OUTFLOW BOUNDARY EXTENDED FROM ALONG THE LA/AR BORDER WESTWARD INTO FAR NORTHEAST TX. THE AIR MASS TO THE SOUTH REMAINS STRONGLY UNSTABLE /MLCAPE 2000-3000 J PER KG/. GIVEN TIME OF DAY WITH THE ONSET OF BOUNDARY LAYER COOLING AND THE FACT THAT LOW-LEVEL WINDS WILL BE WEAKENING...THE POTENTIAL FOR ANY STRONG WIND THREAT AT THE SURFACE IS LIKELY TO REMAIN QUITE LOW. THUS...THIS OUTLOOK WILL NOT INTRODUCE A MARGINAL SEVERE RISK AREA INTO NORTHERN AND CENTRAL LA. ..PETERS.. 08/08/2016Read more
from SPC Forecast Products http://ift.tt/rxAC6Z
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