PBZ issues Area Forecast Discussion (AFD) at Jul 24, 9:09 PM EDT582
FXUS61 KPBZ 250109
AFDPBZ
Area Forecast Discussion
National Weather Service Pittsburgh PA
909 PM EDT Wed Jul 24 2024
.SYNOPSIS...
Showers and storms are expected through through a Thursday
ahead of a cold front. Dry conditions and a warming trend are
expected into the weekend.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
KEY MESSAGES:
- Remnant showers and storms are expected through the late
evening and overnight time period.
- Probability of storm being severe has decreased significant
over the last 2 hours.
----------------------------------------------------------------
Convection outflow has overspread western Pennsylvania and
eastern Ohio region over the last 2 hours. Drier air aloft,
noted earlier, is no longer available for strong to severe wind
gusts associated with downdrafts. At the moment, lightning and
sub- severe wind gusts (less than 45mph) will be the main
threat. A few storms may produce heavy rainfall rates; an
observer in Wheeling, WV received a quick 0.80 inches in less
than an hour.
A few rumbles of thunder are possible through the early
overnight hours as the line progresses through areas south of
Pittsburgh in perhaps a couple hundred joules of elevated
instability, with showers more likely late overnight tonight.
Fog and low stratus are expected for areas dowsed with
precipitation over the last 8 hours. Fog probabilities are
highest in the I-80 corridor and eastern Ohio given the recent
rain and greatest likelihood of clouds clearing. Dense fog
probabilities are around 30% to 40% for now in those areas.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH THURSDAY NIGHT/...
KEY MESSAGES:
- A cold front brings additional shower and thunderstorm
chances, mainly to the southern half of the area.
- Cooler and drier weather moves into the area in the wake of
the cold front.
_________________________________________________________________
With the upper trough continuing to advance eastward towards the
northeastern CONUS and a surface low over southern Ontario
lifting quickly away to the northeast, a weak cold front sags
southeastward across the lower Great Lakes and into the local
area during the day Thursday. This will be the last source of
lift to aid in the development of scattered showers and
thunderstorms, though by that time the best forcing aloft will
have shifted east of the area. With these features being out of
phase, not expecting the convective coverage one might
typically expect along a summer cold front. The best rain
chances will be south of I-70 where scattered showers and storms
may develop as the front moves through in the heat and
instability of the afternoon/evening, while areas farther north
may very well see a dry FROPA. The front pushes through the
area by late Thursday evening, with cooler and drier air
settling in behind it. Lows Thursday night dip below seasonal
normals, into the mid/upper 50s (low 50s north of I-80).
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
KEY MESSAGES:
- Dry conditions with a warming trend expected Friday through
this weekend.
- A couple disturbances may pass through early next week.
- Moderate risk of excessive heat beginning in August.
________________________________________________________________
Ensemble clusters have surprisingly few differences through the
long range forecast, suggesting high confidence in the pattern
through the rest of the month.
That pattern begins with ridging through this weekend with
heights of 500mb heights of 890-940dm forecast through at least
Sunday. From there, the area sits roughly on the backside of the
surface ridge axis, allowing a brief return of warm and moist
southwest flow. This would support a brief unsettled pattern
through the middle of next week with a few passing disturbances.
By the end of next week, ensembles are highly confident in a
strong central CONUS ridge that would place our area in
northwest flow aloft. While these patterns tend to be dry on
average, they are also supportive of severe weather chances.
Severe probabilities increasing are also reflected in the CSU-
MLP. In addition, heat concerns return. Accordingly, CPC has
issued another moderate risk of excessive heat from August 1st
through August 7th. Lastly, with flow from the Canadian Rockies
aloft, wildfire smoke could make its debut to the Pittsburgh
region this year.
&&
.AVIATION /01Z THURSDAY THROUGH MONDAY/...
Convective activity should wane over the next few hours with
loss of instability. Partial clearing with a still-moist
boundary layer is expected to allow for MVFR/IFR conditions in
low clouds and fog later tonight. IFR is most likely north and
west of PIT where clearing will be longer lived behind the cold
front.
Improvement to VFR is expected after 12Z with the crossing
front. Scattered showers may fire once again ahead of the
boundary as it approaches far southern PA and the Mason-Dixon
Line by midday. Showers should end by Thursday evening as the
front exits the region.
.Outlook...
After possible fog Thursday night, VFR returns Friday under
high pressure.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
PA...None.
OH...None.
WV...None.
&&
$$
SYNOPSIS...Hefferan
NEAR TERM...Hefferan
SHORT TERM...Cermak
LONG TERM...Milcarek
AVIATION...Rackley/CL
Source:
PBZ issues Area Forecast Discussion (AFD) at Jul 24, 9:09 PM EDT---------------
If I'm using your data in a way that is against your terms please email the team at "threatweb@pupswoof117.com"! I am a bot who will not respond in the comments at all and is only designed to post RSS feeds!
