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
401 FXUS61 KPBZ 251453 AFDPBZ Area Forecast Discussion National Weather Service Pittsburgh PA 1053 AM EDT Tue Jun 25 2024 .SYNOPSIS... Remnants of a mesoscale convective system may impact the region after 1pm today. Heavy rain showers and sub-severe wind gusts may occur. The threat for strong storms increases Wednesday with a new disturbance. && .NEAR TERM /THROUGH TONIGHT/... KEY MESSAGES: - An upstream disturbance is expected to impact the region early afternoon into the early evening. - Periods of heavy rain and lightning may occur after 1pm for eastern Ohio. - Wind gusts along the line of showers and storms may range from 30mph to 40mph. ------------------------------------------------------------------- A mesoscale convection system (MCS) continues to dive south, within an elongated ridge, across the Great Lakes early this morning. Noted impacts over northern Indiana and northwest Ohio include small hail and wind gusts ranging from 30mph to 45mph. Velocity measurements from surrounding radars over the Midwest indicate a low-level jet of 35mph to 40mph between 1,000ft to 2,000ft. Remnants of this MCS will likely start to impact our region over the next 2 to 4 hours. However, the overall intensity will rapidly dissolve with time given warm air associated with the ridge. A quick period of heavy rainfall rates (1 to 2 inch per hour rates) and 30mph to 40mph wind gusts may observed with the downdrafts. With increasing cloud coverage from outflow of the MCS and precipitation chances, temperatures north of I-70 will likely trend near average. Areas south may trend 5 degrees above average. && .SHORT TERM /WEDNESDAY THROUGH WEDNESDAY NIGHT/... KEY MESSAGES: - Showers and thunderstorms are more likely Wednesday with a crossing front. - Severe storms and flooding will be possible. ------------------------------------------------------------------- A trough and associated cold front cross the region Wednesday, with a late afternoon/evening FROPA. 25th to 75th percentile QPF for KPIT ranges from 0.20" to 0.8", and with convection there will always be a rather large range so this seams reasonable. Similar to Tuesday, the Wednesday convective setup will be modulated by the evolution of Tuesdays convective cold pools. In any case, showers and storms are more likely. SPC is currently carrying a slight risk as far west as PGH and marginal elsewhere, with the primary risk being damaging winds. SPC also shows a 5% and 2% for hail and tornados respectively which lines up fairly well with the latest 00Z CSU machine-learning probabilities. WPC has the entire region under a marginal for flooding. && .LONG TERM /THURSDAY THROUGH MONDAY/... KEY MESSAGES: - Dry weather Thursday through Friday. - Near normal temperatures Thursday, before a late week warmup. - Shower and thunderstorm chances return for the weekend. ------------------------------------------------------------------- In the wake of Wednesday`s front, temperatures return to normal and dry conditions resume as high pressure builds in across the region. A warming trend in temperatures is forecast Friday and into the weekend as heights gradually rise, reaching about 590-592dm by Saturday. Ensembles show about a 50% chance in general of highs hitting 90F on Saturday. There`s a good chance most locations will see apparent temperatures back in the 90s with Tds back up in the upper 60s / low 70s. Showers and thunderstorm chances return with the increased instability and another frontal system Saturday and Sunday. Dry conditions and near to slightly above normal temperatures are forecast early next week as high pressure resumes control. && .AVIATION /14Z TUESDAY THROUGH SATURDAY/... VFR is expected through much of the TAF period. A mesoscale convective system (MCS) was developing across the Western Great Lakes region. This is initially expected to track eastward overnight, before diving to the south following the 1000-500mb thickness pattern and theta e gradient. It appears most of the thunderstorm activity should stay just west of the area where the best instability is expected, though an increase in mid and dense high level clouds is expected. There is some potential the MCS could track further east and reach some Ohio airports, though a rapid weakening in thunderstorms is expected by that time. A few SW wind gusts up to 20 mph are expected today with mixing. Shower and thunderstorm chances increase late tonight with the approach of the next shortwave trough and surface cold front. For now, included a VCSH at the end of the PIT TAF with uncertainty in how much precip development will occur overnight. .Outlook... Restrictions are expected Wednesday with ocnl showers and thunderstorms as a cold front crosses the region. VFR returns Thursday and Friday under high pressure. Restriction, and shower/thunderstorm potential returns Saturday with the approach of a cold front. && .PBZ WATCHES/WARNINGS/ADVISORIES... PA...None. OH...None. WV...None. && $$ SYNOPSIS...Hefferan NEAR TERM...Hefferan SHORT TERM...88 LONG TERM...88 AVIATION...WM/Frazier