Area Forecast Discussion
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FXUS61 KPBZ 210450
Area Forecast Discussion
National Weather Service Pittsburgh PA
1250 AM EDT SAT MAY 21 2016
Low pressure will bring rain tonight and Saturday. Dry and warmer
weather is expected for the first half of next week.
.NEAR TERM /THROUGH TODAY/...
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timing of precipitation and QPF amounts look good based on
upstream observations and ongoing trends. Latest radar shows light
rain now in place over much of the area but more moderate rates
are still to the south. Rain rates will pick up over the next
several hours and peak overnight before diminishing shortly before
daybreak. Expect the heavier showers associated with the front-
left jet quadrant to continue northeast with the core and impact
southern and eastern zones the most. While the most intense rain
will be south and east of the forecast area, amounts of up to a
quarter of an inch an hour will be possible. Previous discussion
Low pressure is progged to track
across the TN Valley tonight, reaching the upper OH valley region
early Saturday morning. Steady rain is expected to move across the
area as the low approaches overnight and Saturday morning. The
upper OH valley low should weaken Saturday as a coastal low
develops, though a deepening upper trough crossing the region
should keep off and on showers in the forecast through the
afternoon. Generally expecting from one third to one inch of rain.
Near seasonal average temperatures are expected tonight, with 10
degree below average levels expected Saturday.
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.SHORT TERM /TONIGHT THROUGH MONDAY/...
Although the primary focus of the precipitation will shift well
to our east with a deepening coastal low, the upper-level trough
axis directly overhead will keep rain showers in the area through
early Sunday morning.
The deepening trough is then progged to become a cut-off upper
low across central PA later Sunday, with additional showers and
isolated thunder in the forecast due to the proximity of the low.
High pressure building in from the west should result in a
clearing trend later Sunday night, and result in dry weather for
the beginning of next week.
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
Overall models show average agreement and continuity with previous
runs with regards to the central conus ridge shifting to the east
and bringing a warming trend in temperatures to the region. Have
maintained a dry forecast through the first half of the week until
flow shifts to the southwest and moisture advection increases.
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
VFR conditions will continue through the evening, although clouds
will lower and thicken with the approach of low pressure from the
southwest. Rain will develop later tonight with condition
deterioration into Saturday morning. Although rainfall is expected
to diminish in coverage after daybreak, ifr ceilings are expected
to persist for much of the day as an upper level trough crosses.
.OUTLOOK /SATURDAY NIGHT THROUGH WEDNESDAY/...
Restrictions are likely to continue into Saturday night, with
improvement on Sunday.