Thursday, July 9, 2009

Forecast still has many problems

Note this forecast will be updated as needed through out the day....
Chances of severe thunderstorms are dropping off rather fast,just like my thinking from yesterday showed...


Forecast is still one big heartburn....Thunderstorm complexes that did form over ND/SD last night was right on track..One Cluster did push into IA...Meantime another complex in SD has been working East/Southeast this morning...What models failed to pick up on last night was the lack of INSTBY over much of MN...So as thunderstorms moved into Western MN that have been weaken...This is evident on the last hour so radar loop...Higher dewpoint did advect into most of MN..Dewpoints range from the middle 50s to middle 60s upper 40s to lower 50s North....My FA still locked under drier air,with dewpoints holding in the upper 40s to middle 50s...
Problems for today....First out of the gates..This morning's Convection over Western MN...This activity has been slowly but surely pushing Eastwards clouds have just about over taken the FA...Thinking is right now...Showers and thunderstorms will be moving into the FA sometime after the noon hr,if this area of showers and thunderstorms can move through and we can get some breaks in the cloud cover..This will also depend on if INSTBY can increase..If not showers/thunderstorms may very well die before reaching the FA...More thunderstorms could fire along the cold front later this afternoon into the over night hrs....Am still worried clouds won't clear out soon enough for really good SFC by time said CLD FNT pushes into the FA.....Next on the track is moisture..FA area still has dry air over head Dewpoints in the 40s and 50s..So deep moisture is not here....Models however do show moisture increasing this afternoon....Southerly LLJ really gets cranking advecting dewpoints in the middle 60s to upper 60s into the FA..I think this may be over done a little...However it's possible...Problem is moisture looks like it's not going to hang around very long...The next problem is going to be the H7 temps....Models showing H7 temps from 9c to 12c..H8 temps are FCSTD to run around 12c....So this afternoon shows a rather strong Cap in place...Lets talk about INSTBY...Models do show this increasing by midday...-2 to around -4.....Still we will need to get breaks into the CLD cover for INSTBY to really get cranking....So looking at all this...My thinking is widespread severe thunderstorms just won't happen...Not saying there won't be any severe thunderstorms,however they will remain ISO to SCTD in nature....Now if things can come together then this whole FSCT will need to updated....So I'm going to go against the SPC on this one...If any thunderstorms can become severe main threat is going to be large hail,areas of damaging winds....Will add the tornado threat back in with very good wind shear over the area...So A few ISO tornadoes are not out of the question...However to many things are still working against all of this..CLD FNT is also on the weaken side....So there is another factor to throw into the mix.....My thinking is the best chance at seeing severe thunderstorms would be over Southern MN and another area would be over Northern parts of MN...My FCST area right now I don't feel we will have severe thunderstorms..Just the run of the mill thunderstorms...Same for tonight.....Will watch it through out the morning hrs and update this as needed....So keep checking back...