7/27/09 Severe Weather Discussion/Forecast

Monday 7/27/09 Day 1 Outlook.

There is a potential for a decent severe weather threat in the Mid Atlantic and Southern New England tomorrow if the atmosphere corroperates. The 00z GFS has CAPE values of 500-2000 across that area and LI values of -2 to -7. The 00z NAM has CAPE values of 500-1500 and LI values of -2 to -7. So we have a good amount of CAPE and LI avaliable for tomorrow. The factor is that we have a cold front coming through the region. I would defiantly not be suprised to see morning sunshine giving us more instability, combined with Temperatures mainly in the 80s, this should give us a decent chance for severe weather in the Mid Atlantic and Southern New England, and there will once again be ample humidity. Overall, I am only 70% confident in this forecast since the cloud cover in the morning/early afternoon will be hard to predict, so if we have more cloud cover, this will lead to less instability and less of a threat for severe weather. Although if we get less cloud cover than expected, there could be more severe weather. This is the reason why I am not sold on this forecast, I wouldn't be suprised if I had to put a slight risk [15% and up] area. So my thoughts are that the areas highlighted in the map will have CAPE values of 1000-2000 possible and LI values of -3 to -7. All of my thoughts on the potential area of severe weather are shown above, the main threats will be damaging wind and large hail. I may do a mid-day update tomorrow if I see any major changes, otherwise that is it. Basically just a severe weather potential in the Mid Atlantic and Northeast.

Comments would be appreciated.