Quantitative Precipitation Forecast Discussion
NWS Weather Prediction Center College Park MD
342 AM EDT Sun Jun 03 2018


Prelim Day 1 QPF Discussion
Valid Jun 03/1200 UTC thru Jun 04/1200 UTC
Reference AWIPS Graphics under...Precip Accum - 24hr


...Eastern U.S....

The stubborn, compact mid-upper level trough across the mid
Atlantic region will finally push offshore later Sun and Sunday
night. The moist cyclonic flow along with the continued anomalous
PWs (1.75-2.00") will maintain a threat for excessive rainfall,
especially early in the period with the better forcing and greater
instability south of the surface frontal boundary. By mid-late
afternoon, the surface front will slide south to near the VA/NC
border, as will the highest 1-3 hour rainfall rates per the HREF
probabilities. WPC will maintain a small slight risk area across
portions of central and south-central VA into eastern VA and
southern MD based on the higher potential for heavy additional
rainfall amounts (per the mutli CAM consensus), along with the low
FFG values (1 hour FFGs of 1" or less). WPC QPF comprised a blend
of a 00Z multi-model consensus (including HREF mean and NBM) along
with continuity (previous forecast).


...Great Lakes/Ohio Valley into the Northeast...

A negatively-tilted upper trough will continue to push showers and
embedded thunderstorms eastward across the Great Lakes and Ohio
Valley today, with the activity then spreading into the Northeast
overnight ahead of the occluded surface front. The progressive
nature of the system along with limited/negligible instability
should limit the potential for heavy amounts, however the ridge of
higher (anomalous) PWs ahead of the upper trough and surface
occlusion remains rather impressive, and as such even without much
if any CAPE well in this region well north of the warm sector,
moderate totals averaging 0.25-0.50+ inch are likely per the
multi-model consensus.


...Southern Rockies/High Plains...

Guidance continues to show a good signal for developing
precipitation, with locally heavy amounts possible across much of
NM into southwest and south-central CO (especially during the
afternoon and evening). Increasing southeasterly low-level inflow
ahead of a well defined, compact mid-upper level shortwave moving
across the Four Corners region is expected to support developing
showers and storms during the afternoon and evening hours, with a
multi-CAM signal for moderate to locally heavy amounts across the
southern Colorado and the New Mexico ranges.

Hurley