Flooding and Heavy Rain in Pennsylvania, May 6 to 7, 2022

Area Forecast Discussion
National Weather Service Pittsburgh PA
828 PM EDT Thu May 5 2022

.SYNOPSIS...
Wet conditions are expected through Saturday with the slow
passage of a low pressure system, which may create localized
water issues. Dry and seasonably warm weather will develop
starting the next work week.

&&

.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
Surface low pressure and its associated warm front will approach
the region from the southwest overnight in response to a
deepening upper level low headed toward the TN River valley.
Increasing jet ascent plus continued warm, moist advection aloft
will promote light rain chances through Friday morning.

&&

.SHORT TERM /6 AM FRIDAY MORNING THROUGH SATURDAY NIGHT/...
Shower and isolated thunderstorm chances will increase Friday
morning through the afternoon as the warm front encroaches from
the south, aided by better jet support and stronger
frontogenesis. This combined with deep moisture that will push
PWAT values near to above the 90th percentile for early May will
increase the risk for heavy rain that could cause flooding.
However, confidence remains too low for a watch due to the lack
of instability to maximize rainfall rates, the spottier nature
of the expected convection, and the potential for the upper dry
slot to move overhead by the early afternoon.

Locations south of Pittsburgh may develop weak instability
during the mid-to-late afternoon, which combined with favorable
shear, will create potential for isolated instances of strong
to severe damaging wind and small hail.

After a potential brief break Friday evening between forcing
mechanisms, rain showers will return late Friday into Saturday.
This will be in response the the sfc low occluding and the upper
low track slowly passing along the southern CWA border. Though
generally light, localized areas may receive periods of heavier
rain as frontogenetic bands develop within the northern
quadrant of the low. This, along with the previous rainfall,
will bear monitoring for potential hazard watch products if
confidence increases in widespread impacts.

Rain will taper off Saturday afternoon and evening as the low
exits east and high pressure builds in from the west. Expect
near to below seasonal average temperature through this period.

&&

.LONG TERM /SUNDAY THROUGH THURSDAY/...
Long range model ensembles indicate a dry period of weather
beginning on Sunday, with dominant high pressure, and warm
temperature.

&&

.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
VFR is expected early in the TAF period as sfc high pressure
shifts E of the rgn. Mid lvl clouds will increase tonight in
warm advection ahead of approaching low pressure. Deterioration
through MVFR, to IFR, is expected overnight as rain overspreads
the area as the sfc low pulls a warm front nwd.

A brief break in the rain and psbl improvement back to low MVFR
is expected by aftn as the initial warm advection surge
diminishes. The sfc low is then progged to track near the PA/WV
border, with additional shra developing. A few tstms are psbl
Fri mid to late aftn near and S of the sfc low track, where
marginal elevated instability is expected. Included a prob30
mention for the most favorable ports (ZZV and MGW.)

.Outlook...
Restrictions should continue Sat with the slow movg sfc low,
with VFR thereafter.

&&

.PBZ WATCHES/WARNINGS/ADVISORIES...
PA...None.
OH...None.
WV...None.

&&

Hazardous Weather Outlook
National Weather Service Pittsburgh PA
829 PM EDT Thu May 5 2022

OHZ040-041-PAZ007>009-013>016-020>023-073-074-WVZ001-070030-
Carroll-Columbiana-Mercer-Venango-Forest-Lawrence-Butler-Clarion-
Jefferson PA-Beaver-Allegheny-Armstrong-Indiana-Westmoreland-
Higher Elevations of Westmoreland-Hancock-
829 PM EDT Thu May 5 2022

This Hazardous Weather Outlook is for east central Ohio, western
Pennsylvania and northern West Virginia.

.DAY ONE...Tonight.

Hazardous weather is not expected at this time.

.DAYS TWO THROUGH SEVEN...Friday through Wednesday.

Multiple rounds of rain showers Friday into Saturday that could be
heavy at time may create localized flooding issues, especially in
flood prone areas. If confidence increases that more widespread
flooding impacts may develop, a Flood Watch may be needed.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not expected at this time.

OHZ039-048>050-057>059-068-069-PAZ029-031-075-076-WVZ002>004-012-021-
509>514-070030-
Tuscarawas-Coshocton-Harrison-Jefferson OH-Muskingum-Guernsey-
Belmont-Noble-Monroe-Washington-Greene-Fayette-
Higher Elevations of Fayette-Brooke-Ohio-Marshall-Wetzel-Marion-
Monongalia-Ridges of Eastern Monongalia and Northwestern Preston-
Preston-Eastern Preston-Western Tucker-Eastern Tucker-
829 PM EDT Thu May 5 2022

This Hazardous Weather Outlook is for east central Ohio, southwest
Pennsylvania, and northern West Virginia.

.DAY ONE...Tonight.

Hazardous weather is not expected at this time.

.DAYS TWO THROUGH SEVEN...Friday through Wednesday.

Multiple rounds of rain showers Friday into Saturday that could be
heavy at time may create localized flooding issues, especially in
flood prone areas. If confidence increases that more widespread
flooding impacts may develop, a Flood Watch may be needed.

In addition, isolated strong to severe storms may develop Friday
afternoon, with the most likely impacts being strong to damaging wind
and small hail.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not expected at this time.