Scientific Forecaster Discussion
Area forecast discussion...updated
National Weather Service Pittsburgh PA
132 am EST Sat Mar 8 2014
a weak cold front will cross the area this afternoon providing the
risk for precipitation. Colder air will settle in on Sunday.
Near term /through today/...
changes in timing to incoming cloud cover overnight and adjusted
Weak cold front will cross the area this afternoon. Models
continue to show the deep moisture and lift behind the boundary...
slowly reaching the area later today. Will push chance probability of precipitation southward
this afternoon...using the movement of shortwave trough as a
Short term /tonight through Monday/...
the first shortwave trough will swing east this evening...
decreasing the coverage of any precipitation. A second and stronger wave
will move southward through the upper Ohio Valley late tonight.
This will necessitate leaving in chance probability of precipitation in the south after
midnight. The second wave will move through quickly as the flow
aloft veers to the northwest. This will push the precipitation south of
my area before dawn. Anything that falls will be light.
Additionally... model thicknesses are showing rain showers
initially...then slowly changing over to snow as cold air advection gets into
Sunshine will return on Sunday as strong surface high builds into
the Midwest and the colder air retreats toward the northeast.
Temperatures will be cooler Sunday...returning to below normal levels.
A dry day Monday with moderating temperatures.
Long term /Monday night through Friday/...
only one system to deal with in the long term and it remains a
question mark. Models have yet to come into agreement on the
interaction between a weak cold front moving through Tuesday and a
surface low that will develop south of the boundary Tuesday night
and move toward the east on Wednesday. Huge differences on timing...
location and strength of the surface low...not only between models...
but also between model runs. One aspect that has been consistent
is warmer air making it far enough north to allow for rain...
eventually changing to snow.
Colder air will move back in for the end of the long term.
Aviation /07z Saturday through Wednesday/...
VFR can be expected through the first half of Saturday with dry
high pressure retaining control of upper Ohio Valley weather. Light
precipitation...and restriction chances will increase Sat afternoon as a
cold front slides over the area. Genl MVFR is anticipated as ceilings
drop below 3kft.
A wind shift from SW to northwest is expected with gusts to 15kts
possible in the afternoon.
Outlook.../Saturday night through Wednesday/...
VFR will rtn with high pressure Sunday. The next chance for genl
restrictions is expected with middle week low pressure.