Possible Significant Severe-Event for Plains Late Wed into Early Thursday
Posted by JAC on 6/15/2010, 7:18 am
South Dakota could be hit by some mafor tornadoes.   ...CNTRL/NRN PLAINS... STRONG HEIGHT FALLS AHEAD OF THE WRN UPPER LOW WILL INDUCE A STRONG ESE LOW-LEVEL FLOW RESPONSE WITH A MOIST AND UNSTABLE AIR MASS SURGING RAPIDLY NWD. AT THE SAME TIME...THE ELEVATED MIXED LAYER /EML/ WILL BUILD ONTO THE PLAINS AND PROVIDE CHALLENGES/ UNCERTAINTIES TO THE OVERALL CONVECTIVE SCENARIO. MAGNITUDE OF THE MOISTURE SURGE MAY YIELD ELEVATED STORMS THROUGHOUT THE DAY ALONG THE ERN EDGE OF THE EML FROM PARTS OF OK/KS NWD INTO THE MO RIVER VALLEY. THESE STORMS MAY PRODUCE HAIL. BUT...MORE SIGNIFICANT SEVERE RISKS MAY EVOLVE LATER IN THE AFTERNOON. INCREASING SWLY FLOW ALOFT WILL INDUCE A LEE TROUGH/DRY LINE FROM ERN MT TO ERN CO BY AFTERNOON. 00Z GFS/NAM SUGGEST THAT A WEAK PV-ANOMALY/TAIL WILL EJECT FROM THE BASE OF THE UPPER LOW AND PROGRESS ONTO THE PLAINS DURING PEAK HEATING. THERE IS REASONABLE EVIDENCE TO SUGGEST THAT HIGH BASED STORMS WILL DEVELOP ALONG THE LEE TROUGH/MOUNTAINS AND POSSIBLY BECOME SEVERE OVER THE HIGH PLAINS OF SW ND...WRN SD AND WRN NEB BY EVENING. WHILE VERTICAL SHEAR WILL BE MODEST AT BEST...STEEP MID-LEVEL LAPSE RATES WILL PROBABLY COMPENSATE WITH SUPERCELLS WITH LARGE HAIL/ISOLATED TORNADOES POSSIBLE. ACTIVITY WILL PROBABLY GROW INTO ONE OR MORE MCS/S OVERNIGHT WITH EVENING HAIL/HIGH WIND THREATS...TURNING MORE INTO AN ELEVATED HAIL THREAT FARTHER E...PARTICULARLY OVER SRN SD AND PARTS OF NWRN/NCNTRL NEB. |
52
In this thread:
Post A Reply
This thread has been archived and can no longer receive replies.