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
211 FXUS61 KPBZ 021123 AFDPBZ Area Forecast Discussion National Weather Service Pittsburgh PA 723 AM EDT Fri Oct 2 2026 .WHAT HAS CHANGED... No major changes to the forecast through the weekend. Frost potential early next week is looking more likely. Updated for the 12z TAF issuance. && .KEY MESSAGES... 1) Showers return with a Friday cold front, with no notable threats for heavy rain or severe thunderstorms. 2) Cooler and mainly dry from this weekend into early next week. Frost is a possibility Tuesday and Wednesday mornings, mainly northeast of Pittsburgh. && .DISCUSSION... KEY MESSAGE 1... A trough over the central Plains will begin to eject east today as the trough lifts into the OH Valley during the day on Friday. A ridge will be present over the southeast/eastern CONUS as this will slowly impede and weaken the front as it approaches. In fact, the northern end of the rain shield the ensembles are advertising seems to shear out and dissipate the precipitation a bit. The NBM shows roughly 50% to 70% of exceeding 0.25" over in our Ohio counties but its more around 30% to 50% for the PA and WV counties. This makes sense as the front seems to deteriorate by the time it begins to push into PA. That said, the probs for SB CAPE to even exceed 250 J/Kg is only 30% to 50% and this area is southeast of Pittsburgh. The other factor is that the SPC only has a general thunder area for the area south of I-70. The WPC does not have a marginal outlook for the area for Friday either. Thus no impacts are expected, although, the 850 MB winds advertise a 30 to 40 knot LL Jet. This might be enough to get a few wind gusts of 20 to 30 knots through the day today but that would be the extent. Also the NBM probs give a 30% to 50% probability for wind gusts above 25 mph and even higher on the ridges. KEY MESSAGE 2... Model ensembles indicate broad upper troughing should persist across the NE CONUS from the weekend into the middle of next week. A southern stream shortwave could bring a few showers to areas south and east of Pittsburgh on Sunday. This disturbance would be followed by an influx of cooler air into the region, dropping temperatures below climatology early next week while another run of dry weather begins thanks to high pressure. One thing to watch will be the potential for frost both Tuesday and Wednesday mornings to the northeast of Pittsburgh, as well as in the usual Laurel Highland/northern West Virginia cold spots. The NBM paints a 50% to 75% chance of low temperatures colder than 37 degrees north of US-422 both mornings - which would be chilly enough for at least patchy frost given clear and calm overnight conditions. Temperatures from Wednesday on should build back towards more seasonal values. && .AVIATION /12Z FRIDAY THROUGH TUESDAY/... VFR will slowly begin to fade as showers along the cold front enter the area. There has been a quick movement down to MVFR and a bottoming out at IFR in ports to our west. These same restrictions will sweep the region this morning. Restrictions will continue through the afternoon before beginning to rise once again from west to east behind the front. The eventual rise back to VFR could be quicker than portrayed in the current TAF. Most restrictions are expected to be on the rise by 00z tonight and trending towards drier across the forecast area by 03z. Lingering cloud cover may preclude efficient radiative cooling and fog formation tonight but, steam fog along area rivers could occur. SWerly winds will veer throughout the day eventually picking up and becoming NNWerly behind the front. Gusts between 15-20 kts are possible behind the front today before slacking again this evening. Outlook... Boundary may stall just south of I-70 with some potential restrictions Sat and Sun at the southern terminals. Otherwise, VFR is progged outside of any morning fog. && .PBZ WATCHES/WARNINGS/ADVISORIES... PA...None. OH...None. WV...None. && $$ DISCUSSION...Shallenberger AVIATION...AK