Afternoon Update on Severe Weather Outlook for Today, July 6, 2009...

Discussion... As of 12:56PM 7/6/09
Latest visible imagery shows well-defined ULL sitting in the vicinity of the Ontario/Quebec border with attendant cold front sitting just to the north of the US border. Recent trends showing CU field now popping up across the Lake Ontario Plain of Upstate NY spanning primarily along and north of I-90 from the Niagara Frontier to the Genesee Valley.

Latest Surface Analysis yields a pool of around 1000 J/KG in place along the I-81 corridor from Messena NY to Syracuse NY out ahead of this developing CU Field. A few storms have also fired to the north into far N New York/Vermont, and see no reason for this development not to occur further south into N Central/E NY as the Afternoon wears on. Hence, will continue D1 SWO as is thru this Afternoon/Evening. Hail will be the lead threat with perhaps an isolated damaging wind gust in the strongest cells.

Previous Discussion below...

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Discussion...
Low Pressure situated well north of the border in the Canadian province of Quebec and it’s attendant cold front will be the triggering mechanism for showers/storms later Today, primarily across Upstate NY/New England.

For all intent and purpose, Mesoscale Forecaster Chris Broyles has a pretty good looking D2 Outlook structure based on 00z runs, and wouldn’t think much change is needed for the rollover into D1.

Strongest deep layer/bulk shear looks to remain dislocated from axis of best destabilization, south of I-90 and north of I-90, respectively. With CAPE of generally 1000-1500 J/KG and Negative Lift around -3 to -5, potential is once again low, but not non-zero for some of the expected storms to reach short-lived severe status. Also, with freezing levels once again unseasonably low and less than 10000ft., added potential is there for a few hailers. Most favorable area looks to reside across N Central NY east into N New England. Debated whether to highlight a 5% wind threat with hail being the lead threat, but for now, will do so with the outside potential for an isolated wind damage report. Late Morning update can re-evaluate and locally fine-tune if conditions should warrant.

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