Area Forecast Discussion
Issued by NWS Pittsburgh, PA
Issued by NWS Pittsburgh, PA
Versions:
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
000 FXUS61 KPBZ 200716 AFDPBZ Area Forecast Discussion National Weather Service Pittsburgh PA 316 AM EDT Sat Jul 20 2024 .SYNOPSIS... Dry weather is expected for most of the area through Sunday night under high pressure. The exception today is a wave of low pressure could bring a few showers or thunderstorms to areas southeast of Pittsburgh. A unsettled weather pattern is expected next week, with periodic chances for showers and thunderstorms. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... KEY MESSAGES: - Dry for much of the area under high pressure - Shower/thunderstorm chances SE of Pittsburgh with a wave of low pressure __________________________________________________________________ Surface high pressure will keep most of the area dry today as it builds further across the Upper Ohio Valley region. The exception will be for areas southeast of Pittsburgh, where a shortwave/vorticity maximum embedded in southwest flow aloft tracks northeastward from the TN Valley. Most of the upper support and ascent will stay southeast of our region, though as convective temperatures are reached, and ascent from the vort max approaches, scattered showers and thunderstorms should develop through the day. Instability should be minimal, with MU CAPEs around 500 j/kg. High temperatures should be similar, or a couple of degrees higher, than yesterday`s readings with slightly higher 1000-500mb heights, and warmer 850mb temperatures. && .SHORT TERM /6 PM THIS EVENING THROUGH MONDAY NIGHT/... KEY MESSAGES: - Dry weather expected tonight through Sunday night - Unsettled weather pattern begins Monday _________________________________________________________________ The vort max will exit off the Mid Atlantic coast this evening, with any showers/storms SE of PIT quickly ending. Ridging, ahead of a Central CONUS trough, will build across the Upper Ohio Valley region tonight through Sunday night. This will maintain (or return) dry weather across the region, along with some increase in temperatures. An unsettled weather pattern begins on Monday, as the Central CONUS trough begins to drift eastward. Moist advection and a shortwave embedded in southwest flow aloft will return scattered showers and thundeerstorms to the region on Monday, continuing Monday night. The Storm Prediction Center has the area included in a general thunderstorm outlook, and this seems reasonable given limited instability. Temperatures are expected to continue to run above average, with dew points increasing back into the 60s by Monday. && .LONG TERM /TUESDAY THROUGH FRIDAY/... KEY MESSAGES: - Periodic shower and thunderstorm chances increase through the week - Above average temperatures expected ________________________________________________________________ Model ensembles indicate the Central CONUS trough will continue a slow eastward drift through the week, approaching and crossing the Upper Ohio Valley region by late week. Continued moist advection and shortwave embedded in southwest flow ahead of the trough, and the late week passage of the trough, will maintain periodic shower and thunderstorm chances through late week. A diurnal trend in the POPs is forecast with daytime instability. Temperatures are expected to average near, to a few degrees above, seasonable levels through the period. && .AVIATION /07Z SATURDAY THROUGH WEDNESDAY/... VFR expected through the TAF period with light to variable winds. With mid to upper-level clouds advancing across the region from a shortwave to our south, probability of river valley fog developing is less than 10%. As the shortwave tracks across the West Virginia ridges, isolated shower and thunderstorms may be observed south of PIT after 18Z. With the 06Z TAF update, adjusted MGW to PROB30 for shower activity. .Outlook... VFR is expected through the Monday under the influence of high pressure. A series of shortwave troughs lifting NE from the Tennessee River Valley will support increased shower/tstm chances along with area restrictions mid-week. && .PBZ WATCHES/WARNINGS/ADVISORIES... PA...None. OH...None. WV...None. && $$ SYNOPSIS...WM NEAR TERM...WM SHORT TERM...WM LONG TERM...WM AVIATION...Hefferan