Mesoscale Precipitation Discussion 0593
NWS Weather Prediction Center College Park MD
352 PM EDT Fri Aug 03 2018

Areas affected...Eastern SD...West-central MD

Concerning...Heavy rainfall...Flash flooding POSSIBLE

Valid 031950Z - 040150Z

Summary...Increasing potential for back-building/training
convection may result in locally heavy amounts, resulting in
hydrologic concerns.

Discussion...SPC Mesoanalysis indicates increasing instability,
with GOES-16 imagery showing developing convection/cooling cloud
tops across southeast North Dakota and northeast South Dakota
ahead of an approaching shortwave trough.  A northeast-southeast
oriented axis of deeper moisture is forecast to deepen further as
southwesterly increases ahead of the approaching wave.  As the low
level inflow strengthens, propagation vectors from recent runs of
the RAP suggest a period of back-building convection across
portions of eastern South Dakota into central Minnesota.  Storms
may train as well before the passage of the shortwave later this
afternoon/evening.  Several of the 12 UTC hi-res models indicate a
good signal for locally heavy amounts within the highlighted
region.  Neighborhood probabilities from the 12 UTC HREF Mean
shows a significant threat for locally heavy amounts on the order
of 2-inches or more within portions of this area by 00 UTC.  This
includes areas where flash flood guidance values are relatively
low - suggesting a heightened threat for hydrologic concerns for
areas where heavy amounts do occur.

Pereira    

ATTN...WFO...ABR...FGF...FSD...MPX...

ATTN...RFC...MBRFC...NCRFC...

LAT...LON   46079611 45889507 45399494 44789529 44229589
            43859673 44009749 44739781 45329772 45889705