LOCAL WEATHER CONDITIONS AT Franklin, Venango Regional Airport Temperature 37.4 F / 3 C Wind Chill 33 F / 1 C Dew Point 37.4 F / 3 C Humidity 100% Wind Speed 5.8 Wind Direction SSE 160 Degrees Visibility 1.25 Miles Sky Conditions overcast at 300 feet Current Weather Light Rain Mist Barometer 29.76 Inches Issued At 01/31/2025 10:40 $$ |
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A Special Weather Statement has been issued for Venango county until 4:00 PM.
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Area Forecast Discussion
Convective Outlooks: Daily Hydrometeorological Data Summary Quantitive Precipitation Forecast Discussion Local Storm Reports (All NWS Pittsburgh areas) Mesoscale Discussions - All States Child Amber Alerts - All States
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FXUS61 KPBZ 311550 AFDPBZ Area Forecast Discussion National Weather Service Pittsburgh PA 1050 AM EST Fri Jan 31 2025 .SYNOPSIS... Rain is expected across the region throughout the day. Well above normal temperatures today as well. Rain will taper off late tonight and may end as light snow showers. Cooler but dry on Saturday. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... KEY MESSAGES: - Widespread rain today. Highest amounts south of I-70 - Temperatures well above normal. - Patchy dense fog through this evening. ---------------------------------------------------------------- 11am update... The forecast for portions of Tucker County remains on track to slightly below forecast guidance, while the rest of the area has accumulated towards the lower end of forecast guidance thus far in low level divergence north of the convergence zone in West Virginia and the deformation zone towards the Great Lakes. Accordingly, the river forecasts have dropped slightly, but rises and ice jams remain possible in the flood watch. As for high- moisture air advecting into cool antecedent conditions with patches of snow still remaining, prolific fog, particularly north of I-70 and in the mountains, has been observed and is expected to continue through mid-day has higher moisture air continually forces deep low saturation as shown on the 12Z sounding. Localized dense fog has justified an SPS. 7am update... Subsidence and weak dry slotting between the deformation zone to the north and frontogenetic forcing to the south as left much of the forecast region under either a drizzle/very light rain or nothing at all. This trend may hold for a few hours until forcing amplifies with the approach of the surface low/upper trough btwn 15z-18z, so trended PoPs to match this expectation. Overall messaging remains the same. Rest of the Discussion... A weak ridge will rest over the region this morning as an upper level low digs into the central CONUS and then moves eastward across the midwest and gulf coast states. Height falls will then ensue this afternoon as the now open wave rushes eastward. A surface low will move eastward from western Illinois this morning reaching central PA sometime early this evening. A plume of moisture, caught in the southerly flow aloft on the eastern flank of the trough, will pump deep moisture into the area throughout the day. A large rain shield will remain parked over the region today as the surface low moves toward the area. Blended mean rainfall amounts range from 0.4-1.30 inches today with the highest amounts generally over northern WV. Probabilities of > 0.50 inches are above 70% across the entire forecast area. The highest probs of > 1.00 inches are focused mainly south of I-70. Probs south of I-70 for > 1.00 inches range from 30% to 70%, with the highest over Tucker county WV. Warm air will surge northward today as well. This will push high temperatures well above seasonal averages. Prob for highs > 50 range from 60%-100% across the southern half of the forecast area, with 10%-40% across the north. Rainfall, and the warm temperatures, will continue the snow melting process. The combination of these will increase the amount of water into area streams and rivers. One other thing to consider is that the ground underneath the snow pack is frozen meaning not much of the rainfall will be absorbed, this will greatly increase runoff. Area rivers, particularly those south of PIT, are expected to rise later today and into Saturday. && .SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY/... KEY MESSAGES: - Rain ends tonight - Dry weather returns Saturday. -------------------------------------------------------------------- Rain will end from north to south tonight as the trough axis rushes eastward. Colder and much drier air will fill in behind the exiting wave. Its not out of the question that a few flakes could mix in on the northern side of the exiting rain shield. River rises will continue Saturday. High pressure will settle in over the area on Saturday as well as a brief period of cold air advection. Lots of sun on Saturday with temperatures falling back to near normal values. && .LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/... KEY MESSAGES: - Slight chance for rain with a Monday cold front - Rain and snow chances return Wednesday with low pressure ------------------------------------------------------------------- Sunday will feature a return to warm and moist southwest flow thanks to an eastward migration of the high pressure, though a clipper system may affect northeast zones with a brief bout of precipitation late Sunday that is most likely rain with light accumulations. This forecast if fairly high confidence given low variability in ensemble clusters. Model ensembles indicate a general zonal flow is expected across the CONUS for much of the long term period, as a trough develops off the Pacific NW coast. A weak cold front embedded in the flow is progged to cross the Upper Ohio Valley region on Monday, with only a slight chance of rain expected. Generally dry weather returns on Tuesday as surface high pressure builds in. Low pressure is expected to develop along a stalled surface boundary across the Mississippi Valley region Tuesday night, approaching the Ohio Valley region on Wednesday, though clustered variability increases with this. Rain chances return with the approach of the low. Some snow is also possible, depending on the exact track of the low and where the surface boundary sets up. Stayed close to the ensemble blend to smooth out some of this uncertainty in the forecast. The more concerning aspect with this secondary system is more potential for higher QPF and additional river rises. Goal posts are currently between 0.2" (10th percentile) and 2" (90th percentile). Temperatures are expected to average above seasonable levels through most of the period, with Tuesday being the coldest day after FROPA. && .AVIATION /16Z FRIDAY THROUGH TUESDAY/... Widespread MVFR/IFR restrictions in rain will continue from this morning with an advancing low pressure system, though dry slotting/weak subsidence may limit rain to areas near/south of KMGW through 15z. Approach of the surface low is expected to increase area rain coverage between 15z-21z with the highest rainfall intensities likely remaining south of PIT. Spotty fog remains a potential through this period due to abundant moisture and rain, warm advection, and melting of residual surface snow. The cold frontal passage is expected in the 20-23z time range, with a possible line of showers and brief gusty winds. Post- frontal dry advection and increased mixing will ease rain coverage and improve vsby restrictions near 00z temporarily but Hi-res models suggest wrap around moisture and cold advection may yield an additional period of IFR cigs and drizzle. Outlook... High pressure and dry advection in northwest flow will end precipitation by 12z Saturday and aide gradual improvements to VFR by Saturday night (near 100% probability). Weak shortwave movement in zonal flow to the north may lead to a period of MVFR cigs (40-60% probability of occurrence) and light rain/drizzle Sunday that favors northwest PA. Periods of gusty wind may also develop as low pressure system cross north of the region through early next week. && .HYDROLOGY... Rainfall amounts between 0.60-1.30 inches falling on a melting snowpack could contribute to significant rises on area rivers, especially in the Mon, Yough and Cheat basins. These rises will certainly disturb areal river ice and could create ice jam flooding. At this time multiple forecast points are forecast to hit action stage but none are currently forecast to hit minor flood stage. Allegheny Basin: Upcoming rainfall and current snowpack are lighter in the Allegheny Basin than others. However, rain on rotting snow, river ice and the heating induced snowmelt are likely to cause rises this weekend of 1-2 feet. These rises could be enough to disturb the current ice coverage on the river and lead to ice jam flooding. At this time no points in the Allegheny Basin are expected to reach action stage. Monongahela, Youghiogheny and Cheat Basins: These basins are grouped together because their anticipated rain totals, snowpack and ice coverage are expected to create similar issues. Rises on the Upper Monongahela and Cheat rivers are expected between 6-12 feet. These rises will certainly disturb any river ice and can exacerbate issues seen across these basins. At this time there are several locations in these basins forecast to reach action stage. Rises on the Lower Monongahela are expected to range between 10-20 feet. This is expected to take all forecast points on the Lower Mon to action, but not to minor flood. Rises on the Youghiogheny are expected to be on the order of 3-6 feet. These rises will certainly disturb thick river ice observed along the river. At this time no points are forecast to reach action stage but issues due to ice jams can bring flood concerns anyway. Ohio and Musk Basins: Expected rainfall totals and observed snow depth is lesser across these basins. However ice coverage is plentiful. Rises on the Ohio are expected to be on the order of 5-10 feet. At this time no points are forecast to move to action stage but the disturbance of ice may cause issues. Rises on the Beaver, Muskingum and Tuscarawas rivers are expected to be on the order of 1-3 feet. At this time no points are expected to move to action stage. However, these rises are sufficient to disturb plentiful areal ice coverage and cause issues. && .PBZ WATCHES/WARNINGS/ADVISORIES... PA...Flood Watch through Saturday afternoon for PAZ073>076. OH...None. WV...Flood Watch through Saturday afternoon for WVZ509>514. && $$ SYNOPSIS...22 NEAR TERM...22/Milcarek SHORT TERM...22 LONG TERM...WM/Milcarek AVIATION...Rackley/Frazier HYDROLOGY... |