National Weather Service Weather Forecast Office

• Home
• Site Map
• News
• Organization
• Search for: NWS All NOAA 

000
FXUS61 KPBZ 221729
AFDPBZ

Area Forecast Discussion
National Weather Service Pittsburgh PA
129 PM EDT Mon Apr 22 2024

.SYNOPSIS...
An overnight frost for insulated valleys in Pennsylvania and
northern West Virginia will be followed by seasonably warm
temperature Tuesday. A passing front will bring rain overnight
Tuesday before a warming trend closes out the week.

&&

.NEAR TERM /THROUGH TONIGHT/...
KEY MESSAGES:

- Frost Advisory is in effect for portions of Pennsylvania and
  West Virginia tonight from 2am to 9am.

------------------------------------------------------------------

Efficient mixing will continue today, pushing temperatures
nearer the NBM 90th percentile, dew points near the NBM 10th
percentile, and allowing for a few fair weather daytime cumulus.
Come nightfall, a loss of mixing and surface decoupling is
expected.

High clouds are expected to progressively advect overnight with
the arrival of upper moisture, although these clouds appear
optically thin when looking upstream on daytime visible
satellite. Overnight, gradient winds will also increase from the
south with the approach of a surface trough.

The frost advisory has been issued for zones in PA and WV where
temperature less than or equal to 36 are forecast, though
hazards should be confined to insulated valleys where winds will
remain calm. Allegheny County has been excluded owing to urban
heat island influences.

&&

.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
KEY MESSAGES:

- Precipitation returns later Tuesday into Wednesday.
- Total precipitation will be relatively low.
----------------------------------------------------------------

Temperatures will continue to trend up Tuesday and cloud
coverage will increase with warm, moist advection ramping up ahead
of an approaching front. Precipitation chances will increase
from west to east later in the afternoon...but be most likely
overnight with frontal passage. Precipitation totals will be
relatively light, ranging from near 0.50" north of I-80 to a
tenth south of the Mason-Dixon line with the higher amounts in
closer proximity to the associated surface low crossing the
Great Lakes.

With cloud coverage and the boundary layer remaining mixed,
overnight lows will be near 50F, but daytime highs should only
reach mid 50s at best as rain exits east and cold advection
behind the front.

With high pressure centering over the region Wednesday night
into Thursday, clouds should be minimal and wind light, so frost
freeze headlines may be needed again.

&&

.LONG TERM /THURSDAY THROUGH SUNDAY/...
KEY MESSAGES:

- Dry conditions resume.
- Frost/Freeze potential early Thursday morning.
- Well above normal temperatures by the end of the weekend.
-------------------------------------------------------------------


High pressure will maintain dry conditions Thursday and through
the day on Friday. With the high well east of the region by the
end of the week, sfc winds will be back to a southerly
direction, and with upper ridging over the region, highs should
be in the upper 60s to low 70s on Friday.

Shower chances increase late Friday and into the weekend as low
pressure advances out of the central CONUS and over the Great
Lakes. Have kept thunder with the warm front out of the forecast
for now with 6hr NBM probs are largely below 10%. At this time
convection looks more likely on Sunday/Monday.

Temperatures will continue to trend warmer through the weekend.
Going by 850mb temperatures and 500mb heights, highs should be in
the upper 70s by Sunday.

&&

.AVIATION /17Z MONDAY THROUGH FRIDAY/...
VFR is expected under the influence of high pressure through the
TAF period. Diurnal heating has resulted in a few afternoon cu
around 4-5kft and W-NW wind around 10kts. Warm advection aloft
ahead of the next shortwave will increase cirrus by 00Z across
the area. It is possible to see some influence in lowering cigs
as the next front begins to impact the area by the end or just
after the end of the TAF period.

.Outlook...
Expect some restrictions with the approach and passage of a low
pressure system late Tuesday into Wednesday creates increased
restriction potential along with widespread rain. There is high
confidence in high pressure supporting VFR conditions to end the
work week.

&&

.PBZ WATCHES/WARNINGS/ADVISORIES...
PA...Frost Advisory from 2 AM to 9 AM EDT Tuesday for PAZ008-009-
     014>016-022-029-031-073>078.
OH...None.
WV...Frost Advisory from 2 AM to 9 AM EDT Tuesday for WVZ021-
     509>512.

&&

$$

SYNOPSIS...Milcarek
NEAR TERM...Milcarek
SHORT TERM...88
LONG TERM...88
AVIATION...Shallenberger