...THERE IS A SLGT RISK OF SVR TSTMS FROM THE CNTRL HIGH PLAINS TO MID-MO VALLEY... ...THERE IS A SLGT RISK OF SVR TSTMS FOR PARTS OF N MN... ...SUMMARY... ISOLATED SEVERE STORMS ARE POSSIBLE THIS AFTERNOON AND EVENING FROM PARTS OF THE UPPER MISSISSIPPI VALLEY TO CENTRAL HIGH PLAINS. ...SYNOPSIS... A QUASI-ZONAL FLOW REGIME WITH MODERATE MID-LEVEL WLYS WILL PREVAIL OVER THE N-CNTRL STATES AS AN UPPER-LEVEL TROUGH BECOMES CENTERED ACROSS NRN MANITOBA. TRAILING PORTION OF A COLD FRONT ASSOCIATED WITH THIS TROUGH SHOULD EXTEND ACROSS THE UPPER MS VALLEY TO NRN PLAINS THIS AFTERNOON. FARTHER S...A LEE TROUGH WILL REMAIN ANCHORED OVER THE CNTRL HIGH PLAINS WITH A QUASI-STATIONARY FRONT ARCING ACROSS S NEB AND A DRYLINE EXTENDING S THROUGH CNTRL KS. A WEAK MID-LEVEL IMPULSE OFF THE NRN CA/ORE COAST WILL SHIFT SLOWLY N. ...CNTRL HIGH PLAINS TO MID-MO VALLEY... RESERVOIR OF RICHER LOW-LEVEL MOISTURE /CHARACTERIZED BY 60S SURFACE DEWPOINTS/ WILL EXIST BENEATH STEEP LAPSE RATES N OF THE QUASI-STATIONARY FRONT. ROBUST DIABATIC WARMING S OF THE FRONT /SURFACE TEMPERATURES APPROACHING 100 DEG F/ WILL CONTRIBUTE TO MLCAPE REACHING 1500-2500 J/KG. THE REGION WILL RESIDE ON THE SRN PERIPHERY OF MODEST MID-LEVEL WLYS...BUT WITH AN ELY COMPONENT TO LOW-LEVEL FLOW...EFFECTIVE SHEAR SHOULD REACH 25-35 KT. AFTERNOON STORMS WILL LIKELY INITIATE ALONG THE HIGHER TERRAIN AND DEVELOP EWD IN THE EVENING AS THE LLJ STRENGTHENS OVER THE CNTRL PLAINS. MULTICELL CLUSTERS SHOULD BE THE PREDOMINANT MODE WITH SEVERE HAIL/WIND AS THE PRIMARY HAZARDS. INCREASINGLY SUBSTANTIAL MLCIN FRI NIGHT RENDERS UNCERTAINTY IN THE ERN EXTENT OF ORGANIZED SEVERE RISK TOWARDS IA. ...N MN... MIDDLE TO UPPER 60S SURFACE DEW POINTS SHOULD LIE AHEAD OF THE IMPINGING COLD FRONT...WHERE ROBUST DESTABILIZATION IS ANTICIPATED IN THE WAKE OF SCATTERED MORNING CONVECTION. MLCAPE SHOULD REACH 1500-2500 J/KG BY PEAK HEATING. MID/UPPER-LEVEL SPEED SHEAR SHOULD BE STRONG BETWEEN 700-250 MB...SUPPORTING POTENTIAL FOR ORGANIZED UPDRAFTS. UNCERTAINTY REMAINS IN THE DEGREE OF STORM COVERAGE GIVEN LITTLE MID-LEVEL HEIGHT CHANGE AND GENERALLY VEERED LOW-LEVEL WINDS AHEAD OF THE BOUNDARY. AMIDST MINIMAL MLCIN...SUFFICIENT SURFACE CONVERGENCE MAY EXIST FOR ISOLATED STORMS PRIMARILY PRODUCING SEVERE HAIL/WIND. ...SW ORE/NE CA... GUIDANCE IS CONSISTENT IN DEPICTING A BELT OF ENHANCED MID-LEVEL SLYS ACROSS THE NRN SIERRA NV TO SRN CASCADE MTNS THIS AFTERNOON. ALTHOUGH HODOGRAPHS SHOULD REMAIN RELATIVELY SMALL...EFFECTIVE SHEAR OF 25-30 KT ALONG WITH STEEP TROPOSPHERIC LAPSE RATES COULD SUPPORT A COUPLE OF MARGINALLY SEVERE WIND/HAIL EVENTS.
Posted on: Fri, 11 Jul 2014 06:19:21 +0000
Trending Topics
Recently Viewed Topics
© 2015