Alert archive / Pennsylvania / Flash Flood Warnings in 2020
Flash Flood Warning 20, NWS Pittsburgh, PA
NWS Pittsburgh, PA issued this flash flood warning at Jul 23, 2020, 8:22 PM EDT for Westmoreland County, Pennsylvania. It was in force for 113 min. No storm report in the archive falls inside the area while it was in force.
The area
The counties it named.
The facts
- Issued
- Jul 23, 2020, 8:22 PM EDT (00:22 UTC)
- Expired
- Jul 23, 2020, 10:15 PM EDT
- In force
- 113 min
- Issued by
- NWS Pittsburgh, PA
- Area
- Storm-based polygon
- Flood severity
- None
County Westmoreland County, PA
The radar
The Pittsburgh radar (KPBZ), 68 km from the middle of the area, began a volume at 00:22 UTC, the scan nearest the moment this went out.
Open the radar archive at this moment
The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.
The nearest sounding before it
Pittsburgh, PA (KPIT), launched 00:00Z, 0.4 hours before the alert went out and 55 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.
- Mixed-layer CAPE
- 1208 J/kg
- Mixed-layer CIN
- -1 J/kg
- Mixed-layer LCL
- 632 m above ground
- 0-6 km bulk shear
- 15 kt
- 0-1 km storm-relative helicity
- 34 m²/s²
- 0-3 km storm-relative helicity
- 30 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
What forecasters said that day
The local office's own words before this flash flood warning went out, 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 this flash flood warning went out at Jul 23, 3:49 PM EDT, 4 hours 33 minutes earlier.
Area forecast discussion, Jul 23, 3:49 PM EDT, 4 hours 33 minutes before
Area Forecast Discussion National Weather Service Pittsburgh PA 349 PM EDT Thu Jul 23 2020 .SYNOPSIS... Scattered showers and thunderstorms will continue to plague the region into Friday. Dry and warmer weather can be expected for the weekend. && .NEAR TERM /UNTIL 6 AM FRIDAY MORNING/... No major changes were needed for tonights forecast as scattered convection will continue to plague the Upr OH as a longwave trough/weak cdfnt slide toward the area. An isolated severe threat in the form of a damaging gust remains possible given a cooling swath of dry air in the mid levels, but deep layer shear is weak and overall mid level temperature remains sufficient warm to impede updraft strength. Areas that clear tonight with progress of the trough/front may experience fog dvlpmnt given rainfall and lingering boundary layer moisture. && .SHORT TERM /6 AM FRIDAY MORNING THROUGH SUNDAY/... The frontal boundary moving through areas southeast of PIT will become more diffuse and weaker with progress; hence, will some showers are possible in that area with limited instability. Building high pressure will keep the remainder of the area dry with seasonable temperature. That high pressure will maintain dry weather for the weekend, but with rising heights, temperature will increase above the calculated normals cumulating in readings almost 10 degrees above by Sunday. && .LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/... Models then indicate the encroachment of a strong shortwave for Monday and Tuesday. That system will bring the next strong thunderstorm threat for next week and will moderate temperature back toward the averages. && .AVIATION /19Z THURSDAY THROUGH TUESDAY/... Scattered convection will continue to plague the Upr OH as a longwave trough/weak cdfnt slide over the area tonight. Scattered restrictions will then give way to areas of fog and stratus with passage of the front. Building high pressure will improve condition through Friday. .Outlook... High pres wl maintain VFR for the weekend. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...None. OH...None. PA...None. WV...None. &&
Hazardous weather outlook, Jul 23, 1:12 PM EDT, 7 hours 10 minutes before
Hazardous Weather Outlook National Weather Service Pittsburgh PA 112 PM EDT Thu Jul 23 2020 MDZ001-OHZ039>041-048>050-057>059-068-069-PAZ007>009-013>016-020>023- 029-031-073>076-WVZ001>004-012-021-509>514-241715- Garrett-Tuscarawas-Carroll-Columbiana-Coshocton-Harrison- Jefferson OH-Muskingum-Guernsey-Belmont-Noble-Monroe-Mercer-Venango- Forest-Lawrence-Butler-Clarion-Jefferson PA-Beaver-Allegheny- Armstrong-Indiana-Washington-Greene-Westmoreland-Westmoreland Ridges- Fayette-Fayette Ridges-Hancock-Brooke-Ohio-Marshall-Wetzel-Marion- Monongalia-Ridges of Eastern Monongalia and Northwestern Preston- Preston-Eastern Preston-Western Tucker-Eastern Tucker- 112 PM EDT Thu Jul 23 2020 This Hazardous Weather Outlook is for western Maryland, east central Ohio, northwest Pennsylvania, southwest Pennsylvania, western Pennsylvania, northern West Virginia and the northern panhandle of West Virginia. .DAY ONE...This afternoon and tonight. Marginal risk for severe thunderstorms this evening. The main threat will be damaging wind gusts. Thunderstorms will also produce heavy downpours which could lead to localized flooding. .DAYS TWO THROUGH SEVEN...Friday through Wednesday. Hazardous weather is not expected at this time. .SPOTTER INFORMATION STATEMENT... Spotter activation is not expected at this time.
In the hours before
Special weather statement, Jul 23, 3:11 PM EDT, 5 hours 11 minutes before
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</html>Special weather statement, Jul 23, 3:31 PM EDT, 4 hours 51 minutes before
Special Weather Statement National Weather Service Pittsburgh PA 331 PM EDT Thu Jul 23 2020 PAZ021-073-232000- Westmoreland-Allegheny- 331 PM EDT Thu Jul 23 2020 ...AN AREA OF STRONG THUNDERSTORMS CAPABLE OF PRODUCING GUSTY WIND WILL AFFECT NORTHEASTERN ALLEGHENY AND NORTHWESTERN WESTMORELAND COUNTIES... At 331 PM EDT, strong thunderstorms were clustered over Wilkinsburg, or near Pittsburgh, moving east at 15 mph. Wind gusts up to 45 mph are possible with this storm. Locations impacted include... Pittsburgh... Penn Hills... Ross Township... Monroeville... McKeesport... Shaler Township... Plum... West Mifflin... Baldwin... Murrysville... Wilkinsburg... New Kensington... This includes the following highways... Pennsylvania Turnpike between mile markers 45 and 63. Interstate 376 in Pennsylvania between mile markers 71 and 84. LAT...LON 4034 7995 4051 8003 4065 7967 4038 7956 TIME...MOT...LOC 1931Z 250DEG 13KT 4045 7991
Special weather statement, Jul 23, 4:04 PM EDT, 4 hours 18 minutes before
Special Weather Statement
National Weather Service Pittsburgh PA
404 PM EDT Thu Jul 23 2020
PAZ021-022-073-232030-
Armstrong-Westmoreland-Allegheny-
404 PM EDT Thu Jul 23 2020
...AN AREA OF STRONG THUNDERSTORMS CAPABLE OF PRODUCING GUSTY WIND
AND HEAVY RAIN WILL AFFECT NORTHEASTERN ALLEGHENY...NORTHWESTERN
WESTMORELAND AND SOUTHWESTERN ARMSTRONG COUNTIES...
At 404 PM EDT, strong thunderstorms were clustered over New
Kensington, or near Penn Hills, moving east at 20 mph.
Wind gusts up to 45 mph are possible with this storm.
Locations impacted include...
Penn Hills... Vandergrift...
Apollo... Plum...
Murrysville... Hampton Township...
New Kensington... Lower Burrell...
Harrison Township... O'hara Township...
Oakmont... Fox Chapel...
This includes Pennsylvania Turnpike between mile markers 41 and 53.
Torrential rainfall also is occurring with this storm and may cause
localized flooding. Do not drive your vehicle through flooded
roadways.
LAT...LON 4047 7984 4059 7994 4067 7971 4067 7969
4068 7969 4073 7955 4051 7946
TIME...MOT...LOC 2004Z 251DEG 17KT 4055 7975The office that day
Everything else NWS Pittsburgh, PA issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 23, 9:23 PM EDT | Areal Flood Advisory | PBZ | Indiana | 112 min |
Nearby
Flash Flood Warnings in Pennsylvania, 2020Every flash flood warning in 2020
Sources
The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.