Multiple rounds of thunderstorms, first from a decaying morning mesoscale convective system and later forming on outflow from earlier activity, produced heavy rainfall on July 1st. 0 inches supported efficient rainfall.
Every event with a place to put it. Tap one for its entry below.
Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.
The episode as NWS PBZ wrote it up.
Multiple rounds of thunderstorms, first from a decaying morning mesoscale convective system and later forming on outflow from earlier activity, produced heavy rainfall on July 1st. Instability was not high, but precipitable water values of 1.8 to 2.0 inches supported efficient rainfall. Localized totals of 1.5 to 2.5 inches, locally higher, produced flash flooding in several areas.
The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS Pittsburgh, PA wrote its last area forecast discussion before the first event at Jul 1, 2:56 PM EST, 1 hour 34 minutes earlier.
Area Forecast Discussion National Weather Service Pittsburgh PA 356 PM EDT Sat Jul 1 2023 .SYNOPSIS... Seasonable, but humid conditions will continue through the Independence Day weekend. Possibly severe thunderstorm chances return to the area this afternoon and again Sunday afternoon and evening. Best chances for severe weather -- primarily strong wind and hail -- will be across areas south of Pittsburgh. Thunderstorm chances are expected once again on Monday, but will be much lower for the Fourth. && .NEAR TERM /UNTIL 6 AM SUNDAY MORNING/... Current conditions feature a somewhat tapped environment for instability currently as a line of showers and thunderstorms have moved through southwestern PA with some locations getting around an inch of rainfall, mainly up into Lawrence, Beaver, Allegheny, and Westmoreland counties. With the morning sounding showing PWATs near 1.8 and a still saturated airmass arriving from the southwest with 1.9 to nearly 2.0 inch PWATs. Minimal instability across the area through the evening will still be enough for a flooding threat, especially where storms organize or train over the same area. Remnant outflows will continue to provide focal points for convection later in the evening. Due to this early convection, cooling temps may allow convective temps to become a bit more difficult to reach. Thus, SPC has removed the slight risk and shunted it to the south but kept the marginal for a few instances of gusty winds. Meanwhile, CAMs seem to indicate an environment where pop up showers are possible but the bulk of the convection under influence of the remnant boundary and an overall moist and unstable airmass seems to be pushing east through the afternoon allowing eastern OH to clear out for the most part. Tonight, the area to the north along I-80 was the least tapped today with the convection. With the approaching warm front from the south overnight and the lake front having an interaction, there will be a renewed focused area for convection. This may be an area for increased threat for flooding and the WPC has adjusted the Slight ERO to the north to cover that region. && .SHORT TERM /6 AM SUNDAY MORNING THROUGH MONDAY NIGHT/... Weak quasi-zonal flow will remain over the Upper Ohio River Valley region Sunday ahead of a developing upper trough over the Central Plains. Approach of shortwaves ahead of that trough within the relatively unchanged environment will offer additional shower and thunderstorm chances -- primarily Sunday afternoon and evening. Once again, there is uncertainty related to severe thunderstorm potential. Afternoon heating and destabilization will support clusters of thunderstorms, but generally weak flow aloft, warm mid-levels, and best instability again located south of the area may make it difficult for severe weather to develop. If strong-to-severe storms were to develop, damaging wind gusts and hail will be the primary threats. Additionally, there is risk for training storms with locally heavy rainfall. This could lead to isolated flash flooding. Thus will focus on the flood threat as the warm front lifts northeast providing an increased areas of focus into Northern WV, Southeastern OH, and Southwestern PA by sunday midday. The best convective threat will be to the south of the early morning convection where heating can reinvigorate development. Mid-level shortwave trough will continue crossing the Great Lakes on Monday, with weak forcing along the slowly moving sfc cold front. This will keep chances for showers and thunderstorms again Monday afternoon, before waning in the evening. Temperatures on Sunday will be similar to the last few days, with slightly cooler temperatures on Monday. && .LONG TERM /TUESDAY THROUGH SATURDAY/... Brief ridging on Tuesday will significantly lower shower/thunderstorm potential for Independence Day. While we can't rule out a isolated shower, kept PoPs generally around 20% or less during the afternoon. Highs will warm into the mid 80s for most with dewpoints in the upper 60s. Heat indices will push into the upper 80s to near 90 across the region during the afternoon. The same can be said for Wednesday with a continued chance of showers and thunderstorms due a stalled boundary along the Allegheny Front but also owing to a more diurnal setup. Once again, Heat Indices values will be a concern on Wednesday but values only crossing 90 degrees will be the concern. A more prominent trough arriving by the middle of next week will increase precipitation chances once again by Thursday and Friday. Warmer temperatures continue through mid-week, with a slight cool down back to average by next weekend. && .AVIATION /20Z SATURDAY THROUGH THURSDAY/... Low confidence forecast. A challenging set of terminals as the forecast is driven by mesoscale features. Carried VCTS or VCSH the first 12 hours or so at most airports. There could be a break after 20Z until 4Zish at several sites as we are between triggers. As the warm front moves through overnight, look for a band of showers with embedded thunderstorms to move through from southwest to northeast. These should produce no worse than MVFR CIGS. The forecast remains iffy Sunday morning as IFR cigs could develop at northern terminals of FKL and DUJ and wouldn't be surprised to see than a little farther south. For now, stuck with LAMP guidance at the two aforementioned airports then low end MVFR elsewhere. Through the morning hours, inserted VFR -SHRA, but again low confidence the entire duration of the forecast. Any thunderstorm or heavier shower given the tropical state of the atmosphere could yield IFR VSBYs. Wind will be from the southwest less than 10kts the entire forecast. .OUTLOOK... Periodic shower/thunderstorm chances plus associated restrictions will continue into Monday with additional shortwave movement ahead of, and the eventually passage of, the next low pressure system. Timing and coverage will likely remain difficult to ascertain during this period, with prior days' convection strongly influencing these factors. Notable ensemble model agreement suggests Tuesday will provide prolonged VFR conditions with dry weather as high pressure builds over the area. && .PBZ WATCHES/WARNINGS/ADVISORIES... PA...None. OH...None. WV...None. && SYNOPSIS...Rackley NEAR TERM...Shallenberger SHORT TERM...Rackley/Shallenberger LONG TERM...Rackley/Shallenberger AVIATION...22/McMullen
Hazardous Weather Outlook National Weather Service Pittsburgh PA 215 PM EDT Sat Jul 1 2023 OHZ039>041-048>050-PAZ007>009-013>016-020>022-073-074-077-078-WVZ001- 002-021815- Tuscarawas-Carroll-Columbiana-Coshocton-Harrison-Jefferson OH-Mercer- Venango-Forest-Lawrence-Butler-Clarion-Jefferson PA-Beaver-Allegheny- Armstrong-Westmoreland-Higher Elevations of Westmoreland-Indiana- Higher Elevations of Indiana-Hancock-Brooke- 215 PM EDT Sat Jul 1 2023 This Hazardous Weather Outlook is for east central Ohio, western Pennsylvania, and northern West Virginia. .DAY ONE...This afternoon and tonight. Isolated severe thunderstorms are possible this evening, though uncertainty in development remains. If the threat develops, the main concern will be damaging wind gusts. Thunderstorms may also produce locally heavy rainfall, which could lead to isolated flash flooding. .DAYS TWO THROUGH SEVEN...Sunday through Friday. Isolated severe thunderstorms will be possible again on Sunday afternoon and evening. Damaging wind and hail will be the primary threats. .SPOTTER INFORMATION STATEMENT... Weather spotters are encouraged to report significant weather conditions according to Standard Operating Procedures. OHZ057>059-068-069-PAZ029-031-075-076-WVZ003-004-012-021-509>514- 021815- Muskingum-Guernsey-Belmont-Noble-Monroe-Washington-Greene-Fayette- Higher Elevations of Fayette-Ohio-Marshall-Wetzel-Marion-Monongalia- Ridges of Eastern Monongalia and Northwestern Preston-Preston- Eastern Preston-Western Tucker-Eastern Tucker- 215 PM EDT Sat Jul 1 2023 This Hazardous Weather Outlook is for east central Ohio, southwest Pennsylvania, and northern West Virginia. .DAY ONE...This afternoon and tonight. Isolated severe thunderstorms are possible this evening, though uncertainty in development remains. If the threat develops, the main concern will be damaging wind gusts. Thunderstorms may also produce locally heavy rainfall, which could lead to isolated flash flooding. .DAYS TWO THROUGH SEVEN...Sunday through Friday. Scattered severe thunderstorms will be possible again on Sunday afternoon and evening. Damaging wind and hail will be the primary threats. Thunderstorms may also produce locally heavy rainfall, which could lead to isolated flash flooding. .SPOTTER INFORMATION STATEMENT... Weather spotters are encouraged to report significant weather conditions according to Standard Operating Procedures.
Special Weather Statement
National Weather Service Pittsburgh PA
1201 PM EDT Sat Jul 1 2023
OHZ041-PAZ013-020-011630-
Columbiana OH-Lawrence PA-Beaver PA-
1201 PM EDT Sat Jul 1 2023
...A STRONG THUNDERSTORM WILL IMPACT EAST CENTRAL COLUMBIANA...
NORTHERN BEAVER AND SOUTHWESTERN LAWRENCE COUNTIES THROUGH 1230 PM
EDT...
At 1201 PM EDT, Doppler radar was tracking a strong thunderstorm near
Calcutta, or near East Palestine, moving northeast at 25 mph.
HAZARD...Wind gusts up to 40 mph.
SOURCE...Radar indicated.
IMPACT...Gusty winds could knock down tree limbs and blow around
unsecured objects.
Locations impacted include...
New Castle, Beaver Falls, East Palestine, Ellwood City, Calcutta,
Ohioville, New Waterford, Patterson Township, Big Beaver, New Beaver,
West Mayfield, Ellport, Koppel, Wampum, South New Castle, Patterson
Heights, New Galilee, Enon Valley, Darlington, and Rogers.
This includes the following highways...
Pennsylvania Turnpike between mile markers 1 and 18.
Interstate 376 in Pennsylvania between mile markers 17 and 33.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
If outdoors, consider seeking shelter inside a building.
&&
LAT...LON 4066 8057 4077 8075 4099 8036 4079 8019
TIME...MOT...LOC 1601Z 239DEG 20KT 4076 8057
MAX HAIL SIZE...0.00 IN
MAX WIND GUST...40 MPH
MilcarekSpecial Weather Statement
National Weather Service Pittsburgh PA
207 PM EDT Sat Jul 1 2023
PAZ077-078-011830-
Higher Elevations of Indiana PA-Indiana PA-
207 PM EDT Sat Jul 1 2023
...A STRONG THUNDERSTORM WILL IMPACT EAST CENTRAL INDIANA COUNTY
THROUGH 230 PM EDT...
At 207 PM EDT, Doppler radar was tracking a strong thunderstorm 8
miles west of Northern Cambria, or 11 miles east of Indiana, moving
east at 25 mph.
HAZARD...Wind gusts up to 40 mph.
SOURCE...Radar indicated.
IMPACT...Gusty winds could knock down tree limbs and blow around
unsecured objects.
Locations impacted include...
Clymer, Cherry Tree, Dixonville, Commodore, and Yellow Creek State
Park.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
If outdoors, consider seeking shelter inside a building.
&&
LAT...LON 4072 7881 4057 7888 4055 7902 4070 7907
4081 7881 4072 7880
TIME...MOT...LOC 1807Z 248DEG 20KT 4065 7895
MAX HAIL SIZE...0.00 IN
MAX WIND GUST...40 MPH
MilcarekThe Pittsburgh radar (KPBZ), 67 km away, was scanning. The volume nearest the first event began at 21:29 UTC.
8 flash flood. Local standard time, as filed.
Green Valley Road was closed due to flooding.
Water was observed flowing into the Marguerite Volunteer Fire Department.
A car was reported to be stuck in flood waters on Mount Vernon Drive, and the road was shut down.
Thompson Run Road was flooded and closed.
Universal Road was flooded and closed.
Verona Road was closed due to flood waters and debris.
Flooding was observed in the Clarion Mall parking lot.
Water was observed to be entering houses on Madison Street.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Pennsylvania in 2023Every state in 2023This day in weather historyWarnings in Pennsylvania, July 2023
NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 1120149, 1120150, 1120151, 1120152, 1120153, 1120154, 1120155, 1120156.