355
FXUS61 KPBZ 221055
AFDPBZ

Area Forecast Discussion
National Weather Service Pittsburgh PA
655 AM EDT Sat Jun 22 2024

.SYNOPSIS...
Dangerous heat will continue today. Showers and thunderstorms
return Sunday with a crossing cold front. A few of these storms
could be severe. Temperatures closer to seasonable levels are
expected behind the front on Monday.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
KEY MESSAGES:

- Dangerous heat continues today
- Excessive Heat Warning and Heat Advisory remain in effect
-------------------------------------------------------------------

Update...
Reduced the coverage of the patchy fog this morning, based on
recent satellite and surface observations.

Previous discussion...
The upper high remains across much of the South Central and
Southeast CONUS, with the Upper Ohio Valley region on the
northern periphery of the high. The high, along with low and mid
level ridging, will keep most of the area dry today.

There could be isolated afternoon showers and thunderstorms
that develop north of I 70 as convective temperatures are
reached, though the more likely scenario will be cumulus cloud
formation. Dry air aloft should make it difficult for
shower/thunderstorm development to occur, though areas closer to
I 80 could see a slightly higher potential as the lake breeze
moves south.

The main story today will be the heat. 500mb heights will be
similar to Friday, before beginning to fall slightly later in
the day. 850 mb temperatures are progged to be near, or slightly
higher than Friday, peaking near 20 deg C. Overall, with the
mostly sunny skies and very little if any convection, high
temperatures should be similar to Friday`s readings. Heat
indices are expected to range from 95 to 100, outside of the
higher terrain of WV. Will maintain the current heat headlines
through 8 PM.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY NIGHT/...
KEY MESSAGES:


- Crossing cold front brings showers and thunderstorms Sunday
- Severe storms possible Sunday
- Return to seasonable temperatures on Monday
-------------------------------------------------------------------

Very warm temperatures will continue tonight as cloud cover and
southwest wind increase tonight ahead of an approaching cold
front. A shortwave trough, and the associated cold front, is
expected to approach the region Sunday. Most available model
output indicates a prefrontal trough will cross the region from
mid morning through early afternoon, with the cold front
crossing through the late afternoon/evening.

Increasing instability and shear is progged through the day,
with ensemble based mean MU CAPE 1500-2000 j/kg by Sunday
afternoon/evening, with the max surface based CAPE 2000-3000
j/kg. 0-6km bulk shear values also increase to 35-40kt, with dry
mid level air enhancing downdraft CAPE. A low level jet from
35-40kt at 850mb will also enhance the damaging wind potential.

Curved hodographs in the lower levels also indicate some
rotation/isolated tornado potential. The Storm Prediction Center
has placed much of western PA in a Slight Risk for severe
storms. The main hazard is expected to be damaging wind, though
with the curved hodographs and shear isolated tornadoes are also
possible. The Slight Risk area is surrounded by a Marginal Risk,
where FROPA timing and shear profiles are slightly less
favorable for severe storms.

The cold front will complete its passage Sunday evening, with
showers and thunderstorms ending from W-E. Surface high pressure
is expected to build under a crossing upper trough on Monday.
This should return mainly dry, and more seasonable weather to
the region.

&&

.LONG TERM /TUESDAY THROUGH FRIDAY/...
KEY MESSAGES:

-Above average temperatures return
-Mainly dry to start and end the work week, with shower and
 thunderstorms for mid week
-------------------------------------------------------------------

An upper ridge, ahead of an approaching Midwest trough, will
maintain dry weather on Tuesday. Rising 1000-500mb heights and
warm advection will drive temperatures from 5 to 10 degrees
above average.

The trough, and its associated surface cold front, will approach
and cross the region late Tuesday night through Wednesday
evening, with shower and thunderstorm chances returning. Building
high pressure will return dry weather for Friday, with
temperatures closer to average.

&&

.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
High probability for VFR to persist through the TAF period under
the influence of high pressure. Warm, dry air aloft should limit
convective initiation and keep probabilities very low of
terminal impact with an afternoon thunderstorm.

Approach of an upper level shortwave and associated cold front
will increase thunderstorm chances at the end to after the TAF
period.

.Outlook...
Showers and thunderstorms are likely, with associated
restrictions, along and ahead of an advancing cold front Sunday.
Timing favors near to after 18z Sunday (2pm EDT) through 06z
Monday (2am EDT). High pressure and northerly flow aloft will
establish dry and more seasonable conditions for the start of
the next work week.

&&

.CLIMATE...
The area has the potential to break various heat-related
records.

There is low probability that climate sites approach the
highest temperatures recorded in the 21st century:

Pittsburgh, PA:       98F  (7/7/2012)
Wheeling, WV:         98F  (7/7/2012)
Morgantown, WV:       101F (7/7/2012)
New Philadelphia, OH: 101F (7/7/2012)
Zanesville, OH:       101F (7/7/2012)
DuBois, PA:           101F (7/22/2011)

There is a low probability many June all-time temperature
records may be at stake:

PIT: 98F (1988)
HLG: 100F (1933)
MGW: 99F (1893)
PHD: 99F (1988)
ZZV: 101F (1988,1934)
DUJ: 92F (1969)  *RECORD TIED ON 6/18/24*

Daily high maximum (left) and high minimum (right) temperature
records are at stake for:

Saturday, June 22nd
Pittsburgh, PA:       98F  (1988)     75F  (1988)
Wheeling, WV:         95F  (1923)     72F  (2011)
Morgantown, WV:       96F  (1923,1988)73F  (1988)
New Philadelphia, OH: 97F  (1988)     71F  (1997)
Zanesville, OH:       99F  (1988)     71F  (1997)
DuBois, PA:           91F  (2022)     68F  (2022)

&&

.PBZ WATCHES/WARNINGS/ADVISORIES...
PA...Heat Advisory until 8 PM EDT this evening for PAZ007>009-013-
     015-016-022-031-074-076>078.
     Excessive Heat Warning until 8 PM EDT this evening for PAZ014-
     020-021-029-073-075.
OH...Heat Advisory until 8 PM EDT this evening for OHZ039>041-
     048>050-057>059-068-069.
WV...Heat Advisory until 8 PM EDT this evening for WVZ001>004-012-
     021-509>511.

&&

$$

SYNOPSIS...WM
NEAR TERM...WM
SHORT TERM...WM
LONG TERM...WM
AVIATION...Frazier
CLIMATE...