![National Oceanic and Atmospheric Administration](/build/images/header/noaa.d87e0251.png)
![National Weather Service](/build/images/header/nws.4e6585d8.png)
![United States Department of Commerce](/build/images/header/doc.b38ba91a.png)
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
629 FXUS61 KPBZ 300742 AFDPBZ Area Forecast Discussion National Weather Service Pittsburgh PA 342 AM EDT Sun Jun 30 2024 .SYNOPSIS... Renewed showers and storms develop early this morning. A cold front moves across the region late this morning through this afternoon, with high pressure building in its wake. && .NEAR TERM /TODAY AND TONIGHT/... KEY MESSAGES: - Scattered showers and thunderstorms possible along and ahead of a passing cold front this morning/afternoon. - A few storms could become strong, with damaging winds the primary threat. - Cooler and drier weather expected tonight behind the front. ------------------------------------------------------------------- Most locations are still hovering in the mid to upper 70 per latest obs and little additional cooling is expected before sunrise. This, combined with dewpoints in the low to mid 70s, has allowed marginal instability to linger through the night, supporting some isolated shower and thunderstorm activity predominantly over northeastern West Virginia and portions of central/eastern Ohio. Expect shower and thunderstorm activity to increase over the rest of the area after sunrise with the onset of daytime heating. Flow aloft has weakened and as a result deep-layer bulk shear has decreased to around 30 knots, which is still enough to carry a low-end threat for damaging winds in any stronger thunderstorms that develop. The Storm Prediction Center has maintained a Marginal Risk (Level 1 out of 5) for this severe threat primarily southeast of the Pittsburgh metro, across the high terrain of SW PA and much of northern WV. Convective activity promptly ends with the passage of the cold front, which doesn`t look to occur until late morning through afternoon hours as it is still located over the Michigan LP as of writing this discussion. Behind the front, cooler and drier air advects into the region, providing relief from the heat and humidity that has plagued us since Friday night and allowing temperatures to dip into the 50s overnight. && .SHORT TERM /MONDAY THROUGH MONDAY NIGHT/... KEY MESSAGES: - Drier air builds in with cooler temperatures. ------------------------------------------------------------------- Dry weather and below normal temperatures prevail with high confidence Monday and Monday night as heights begin to rise and high pressure builds east. In fact, latest HREF probabilities show most locations having a <30% chance of reaching 75 degrees, with the exception being urban areas (e.g., Pittsburgh metro) and portions of eastern OH south of I-70 where the probabilities for reaching 75 degrees are closer to 50%. Low temperatures Monday night dip into the low to mid 50s, roughly 7-10 degrees below normal for this time of year. && .LONG TERM /TUESDAY THROUGH SATURDAY/... KEY MESSAGES: - Dry weather continues Tuesday with warming temperatures. - Showers and thunderstorms expected Wednesday through the end of the work week with the return of a more active pattern. ------------------------------------------------------------------- Good agreement amongst the various ensemble clusters supports dry weather on Tuesday as ECONUS ridging builds. Temperatures begin to rebound as flow becomes more south of east and pushes highs back toward or a couple degrees above normal. By mid-week, ensembles break the ridge down and shunt it southward over the Southeast CONUS and Gulf Coast, leaving zonal flow over the Ohio Valley and lower Great Lakes while lower heights settle in upstream over the upper Great Lakes and Midwest. This patten is certainly more active than the first half of the week, promoting surface low pressure over southern Ontario that quickly tracks northeastward and leaves a trailing cold front sagging southward into our area late Wednesday into Thursday. There is some minor concern at this time that the zonal flow overtop what appears to be a slowing and weakening/diffusing cold front could lead to a setup where multiple rounds of showers and storms develop along said east- west oriented boundary in a moisture-rich environment (ensemble mean PWATs surpassing 1.75 inches), leading to training of thunderstorms and flooding rain potential. It`s too far out to say any of this with certainty, but I would like to see the pattern become a bit more progressive to prevent the front from slowing or stalling over the local area and put these concerns at ease. Additionally, machine learning continues to highlight some severe potential with this pattern as the front will initially be moving into a warm and moist airmass, though weak flow aloft resulting in limited bulk shear is helping to keep the overall threat low at this time. Still, this too will bare watching over coming days. && .AVIATION /06Z SUNDAY THROUGH THURSDAY/... Ports are beginning their morning falls from VFR to MVFR in low clouds, with temporary IFR possible at FKL and DUJ. This is related to some cooling in a deep saturated near-surface layer. This is expected to persist through the morning before scattering and lifting to VFR is expected for the day with mixing. Coverage of storms, or even showers, appears lack-luster save the area around MGW, this morning. A slight uptick in coverage is expected immediately ahead of the crossing cold front. Current thoughts are that coverage will remain to isolated to denote at any port for now save some temporary showers in FKL and DUJ with more saturated low levels. VCSH notes the low- confidence, and the timing is noted in the TAF group. As the front slowly crosses, development might get slightly more robust towards LBE and MGW utilizing some heating in the late morning and early afternoon, but again, too low confidence to pin down. VFR with daytime gusts into 20-25kt range is possible with post-frontal mixing into an increasing pressure gradient. Stratocumulus decks may try to fill in tomorrow night in northwest flow; MVFR after 06Z was noted for now. .Outlook... VFR is expected until a slow moving front sets up across the region Wednesday and Thursday. && .PBZ WATCHES/WARNINGS/ADVISORIES... PA...None. OH...None. WV...None. && $$ SYNOPSIS...Cermak NEAR TERM...Cermak SHORT TERM...Cermak LONG TERM...Cermak AVIATION...Milcarek