Quantitative Precipitation Forecast Discussion
NWS Weather Prediction Center College Park MD
239 PM EDT Tue May 29 2018


Prelim Day 1 QPF Discussion
Valid May 30/0000 UTC thru May 31/0000 UTC
Reference AWIPS Graphics under...Precip Accum - 24hr


Day 1

...Alberto / Southeast U.S. / Ohio and Tennessee valleys/ southern
Appalachians...

Based on the consensus of the 12z hi-res models, made an eastward
adjustment to the anticipated axis of heavier amounts near the
track of the center.  There remains a good signal for 1-2 inch,
with locally heavier amounts near the track of the center,
especially early in the period as the system moves across western
Tennessee into the lower Ohio valley this evening.  Further to the
south, there is still a good indication as well for additional
locally heavy amounts along the trailing inflow axis across
Alabama, as well as into the upslope regions of the southern
Appalachians extending from northern Georgia to southwest
Virginia.  The HREF Mean was utilized as a starting point for WPC
QPF across much of the region.

...Eastern Kansas and central to eastern Oklahoma...

Still a good model signal for convective development to produce
moderate to heavy rain totals as a progressive shortwave trough
moves into the central Plains this afternoon.  Based on the
consensus of the hi-res models, adjusted the axis of heavier
amounts further to the south across central into southeastern
Oklahoma this afternoon-evening.  Here also, WPC QPF utilized the
HREF Mean as a starting point.

...Northern Plains and upper Midwest...

A negatively-tilted trough comprised of an upper low lifting out
of the northern High Plains and shortwave energy emanating from
the central Plains is expected to pivot across the Dakotas and
Nebraska into the upper Mississippi valley on Wed.  Deep
southwesterly flow ahead of the trough is expected to tap some of
the deep moisture associated with Alberto, supporting the
development of moderate to heavy rains across the upper
Mississippi valley during the afternoon/evening hours, with
lighter amounts further to the west in a developing deformation
zone back across the Dakotas.

Pereira