Thursday, May 02, 2013

High Pressure Island

The influences of high pressure that is currently over Eastern Canada will only increase in the coming days as the high center gets squeezed and pushed to the southwest. In many respects, it will end up acting as a bit of an island over the region compared to three other features of note to our west, east, and south.  This high builds down from the northeast, resulting in slightly cooler temperatures for Friday and Saturday compared to what we had the past three days, but it will shield us from each of the three disturbances through the weekend.

The cold core low in the Atlantic will spin back around and merge back into the larger ocean storm that it was spun off from.  It will slightly enhance the onshore flow tomorrow and nudge temperatures down up to five degrees from today's highs, especially inland.   The low pressure center in the Midwest will spin around out there, dropping rain and some snow across areas that really don't want the latter and generally could use more of the former.  The feature in the Gulf will enhance precipitation for Florida and the Gulf Coast for the next couple of days.

The system that will impact us, eventually, is the Midwest low.  It will take until next week to get here, with modeling now varying a bit on timing of arrival.  GFS is earlier by 12 hours, with Tuesday afternoon the timeframe it moves into the area.  The Euro suggests Wednesday.  Both suggest the shower threat holds off through the weekend and also through Monday.  The cutoff low gradually rambles on through with some showers but modeling as of now suggests the bulk of the threat is south of the city for the middle of next week.