Quantitative Precipitation Forecast Discussion
NWS Weather Prediction Center College Park MD
1222 AM EST Wed Mar 07 2018


Prelim Day 1 QPF Discussion
Valid Mar 07/1200 UTC through Mar 08/1200 UTC
Reference AWIPS Graphics under...Precip Accum - 24hr


Day 1...

...Great Lakes/Northeast/FL...
Dynamics from an upper level trough have induced a cyclone which
is slowly deepening as it moves across eastern North Carolina,
expected deepen more rapidly as it moves up the coast offshore New
England.  As it strengthens, frontogenesis in the 850-650 hPa
layer strengthens across the northern Mid-Atlantic and coastal
sections of New England, which will be the main focus for heavy
precipitation, mostly wintry.  The guidance is disagreeable
concerning how far north and northwest to extend heavy
precipitation across northern New England and eastern NY, with the
mesoscale guidance a bit more northerly than the global/NAM
guidance.  For now, maintained reasonable continuity and left the
00z ARW out of the mix.  It would not be a surprise if amounts
across eastern NY were trimmed back a little in the next QPF cycle.

Another highlight is a deep layer circulation over MI/Lake Huron
where a combination of low level frontogenesis and lake
effect/enhancement should be able to afford respectable totals
near the Tip of the Mitt (northern Lower Peninsula) with local
0.25"+ spots across portions of the Upper Peninsula of MI. 

Down south across FL, modest precipitation is expected as the
system's cold front moves through the central into the southern
peninsula.

The day 1 QPF was composed of a blend of WPC continuity, the 00z
NAM, the 00z GFS, the 12z ECMWF, the 00z NMMB, and the 02z
National Blend of Models with some components of the 00z in-house
bias corrected QPF and 00z UKMET factored in manually.  For winter
weather/snow impacts, consult the WPC suite of winter weather
products.

Roth