Quantitative Precipitation Forecast Discussion
NWS Weather Prediction Center College Park MD
1222 AM EST Fri Mar 02 2018


Prelim Day 1 QPF Discussion
Valid Mar 02/1200 UTC thru Mar 03/1200 UTC
Reference AWIPS Graphics under...Precip Accum - 24hr


Day 1


...Eastern U.S...
Vigorous coastal cyclone development is expected within the
climatologically favored area for March off Long Island through
early Saturday as an upper level low closes off overhead.  Warm
advection is contributing to the initial expansion of rainfall
into the Mid-Atlantic and southern New England states at this
time.  This event will become more intensely focused as the
coastal low develops which strengthens frontogenesis in the
850-650 hPa layer. All these ideas fit well with the previously
issued WPC forecast, which we retained.  The biggest adjustment
needed was to lower amounts per the recent guidance across
northeast NY and northern New England.

The 00z GEFS-based QPF re-forecast data, based on analog events,
suggests a swath of 3 to 5 inch areal average QPF across some
portion of the Northeast.  Per information received from
SAB/NESDIS, the December 11-12, 1992 nor'easter is a particularly
good analog for the precipitation expected for southern New
England -- 4-8" fell aceross southeast MA during that intense
nor'easter.  Other possible analogs pointed out by the BOX/Taunton
MA office were the March 7, 2013 and April 1, 1997 events.


...Western U.S...
A deep layer cyclone moves southeast into western OR Friday
night/early Saturday morning.  There is a good QPF consensus among
the models out west. WPC QPF was based strongly on the previous
WPC forecast since it was close to the most recent model guidance.

Roth/Burke