Saturday, April 9, 2011

***SEVERE THUNDERSTORMS****

***SEVERE WEATHER OUTBREAK LOOKING LIKELY***



This would include large hail, damaging winds, Tornadoes…Some tornadoes could be strong!
 See map below as it will stand from yesterday.

This discussion will focus on the severe thunderstorm outbreak that could happen throughout much of the FA…Will also talk about what could limit the factors to this severe weather episode……

Looking at the SFC charts first…This morning we find a frontal boundary out over far Northwestern WI reaching to a trof or a weak area of low pressure over South central ND. The frontal boundary extends to the Southwest into WY/CO area to another area of low pressure which is getting its act going…. Warm front still sitting down over KS and MO this early morning…

Low pressure/shot wave is forecasted to eject Northeast towards MN as this happens the warm front is forecast to start its journey Northwards timing on how fast the warm front will make it North is still somewhat unclear..Nam seems to be a little faster with the overall movement of the whole system..GFS/EC have had the best handle over the last few days..So have decided to blend all three….Warm front should be in Southern MN/Northern IA by 00Z Sunday…..For tonight thinking is an area of MCS will form along the warm front and they should left Northeast into the area….LLJ is forecast to crank up this aid in WAA and moisture into the area…2m Dewpoints later tonight are forecasted to increase to 50 from Central Burnett/Washburn/Southern Sawyer Counties and points South of that line as the warm front surges Northwards MCS are forecasted to move into the FA…Some of these storms could be severe…Main threat later tonight would be large hail along with some damaging winds…..

Tomorrow….

This day still remains a little problematic …..In the early morning hrs ongoing showers/thunderstorms with a few severe thunderstorms will be likely…This activity is forecasted to weaken as it moves Northeast into more stable air…Warm front should be close to Central Burnett/Washburn/Sawyer Counties….Dry air is forecasted to punch Northwards into the area by mid morning/early afternoon…Should see a period of some sunshine, this will allow for SFC which in return should yield for temps in the upper 60 to middle 70s moisture is still forecasted to increase with 2m dewpoints going up to around 55/60…Low pressure is forecasted to lift into Central MN in the afternoon this will also push a cold front towards the area by late afternoon through the mid evening hrs…. CAPE increases to around 1500 J/K to 2000 J/K. LIFTED INDEX shoots to around -4 to -6 in the afternoon…Shear values right around 60 KT. Mid level jet up around 100 KT….This all is setting the stage for what could be a severe weather outbreak across a good chunk of the FA….Main threat, large hail, damaging winds and tornadoes will be possible… Some tornadoes could be strong…..

Limiting factors to all this…..Would be as follows….Clouds/showers and storms from the overnight hrs hang in longer than forecasted, causing less SFC heating… The warm front sits further South than forecasted..Cap should not be a problem….So we will have to see how the overnight MCS plays into all this, if they remain strong enough it may be enough to keep the warm front South into my far Southern FA…..

Listen to NOAA weather radio/your local News Media for the latest on this possible severe weather outbreak….