Quantitative Precipitation Forecast Discussion
NWS Weather Prediction Center College Park MD
1156 PM EST Fri Mar 02 2018


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


Day 1

...Western U.S...
The combination of onshore flow and shortwaves moving around the
southern and eastern side of a slow-moving deep layer cyclone will
urge precipitation -- which could be heavy -- slowly through
southern California, with overlapping 850-650 hPA frontogenesis
across the Great Basin causing moderate to heavy precipitation
with time.  WPC QPF trended upward across southeast Montana to
better fit the current model consensus, but remains close to
continuity elsewhere.  In many spots, the WPC QPF best resembles
the 00z UKMET.

For the precipitation in southern CA, went towards a blend of the
deterministic and mesoscale guidance to try to pick a reasonable
middle ground due to the existing spread and to account for
SGX/San Diego's impressions that the mesoscale guidance has been
high biased in their county warning area as of late.


Elsewhere, hydrologically significant precipitation is not
expected.

Roth