DSM area analysis

Models agree on low pressure lifting NE or NNE form eastern NE into MN through the afternoon.  As of 19Z, all of IA was in the warm sector, with a cold front expected to cross form the west during the afternoon/early evening.  the 12 Z NAM puts the front near DSM at 0Z; the 12Z GFS still has it just to the west.

Earlier convection is exiting stage right, and some clearing is taking place in western IA.  We’re getting rapid scan GOES data today, so we’ll be monitoring the boundary structures that are evident on the imagery.  Below is the CI product superimposed over the visible image…we’re seeing 67% probability of development of 35 dbz returns in the next hour or so along these boundaries.

As this activity develops and moves eastward, Nearcast forecast theta-e difference by 22Z would indicate pockets of instability (in an area of closer to neutral stability) moving in over the next few hours from the west.  Will be interesting to see how this translates into storm coverage, or even storm mode, as the front moves in.

And in the time it’s taken me to work on the above…we’re seeing gradually developing convection marching to the NE/IA border in an area marked by the CI earlier.  Only low to moderate hits on ProbSevere (45% or less by 1930Z).

Do have LAPS data today, but a late realignment of the domain has the model playing catch-up.  Will comment later.

Wx briefing indicated increasing chances of UH tracks in our area, especially in our northeastern counties…watching for supercells with tornadoes and hail…and some severe wind

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