Indiana County Being Split Into Two Zones

Zone Changes

Effective 4 PM EDT, March 8, 2023, Indiana county public forecast zones for the National Weather Service Pittsburgh (PBZ) will be split into two zones. Please read the overview sections below for details or if you prefer, jump to the images or table below.

Overview (public zones)

The National Weather Service Pittsburgh(PBZ) will split Indiana county Pennsylvania into two segments within the County Warning Area (CWA).

In Pennsylvania

Indiana county will be split into two segments, Indiana County and Higher Elevations of Indiana County.


Map showing original, single zone for Indiana County.	Map showing new, split zones for Indiana County.

Click here for a close-up pdf map showing towns and roads.

Justification

While the western part of the county lies at around 1,200 ft elevation, terrain in the eastern section of the county climbs to nearly 2,000 feet. This has a notable impact on temperature, precipitation accumulation (the eastern part of Indiana County lies within sharp, terrain-influenced average rain and snow accumulation gradients), and wind. Local officials have noticed numerous impactful accidents along U.S. 22 (which traverses the county west to east) due to the terrain-influenced change in weather as traffic heads east.

To mitigate these concerns, and to add more precision to text forecasts and long-fuse watches, warnings and advisories, WFO Pittsburgh is proposing a reconfiguration of Indiana County into two forecast zones, the latter of which will align with the terrain incline and higher-elevation plateau of the eastern part of the county.

This zone split will lead to greater accuracy in forecasts and messaging by tailoring the weather impacts to the geography of the county. After the split, those residents in the eastern portion will receive better-tailored warnings that often are lost within a zone average-based advisory headline.

Table 1: WFO PBZ Affected Public Weather Forecast Zones

Current Zone Name / Current UGZ (Z)

New Public Zone Name / New UGZ (Z)

Indiana (PA023)

Indiana (PAZ077)

Higher Elevations of Indiana (PAZ078)

Table 2: WFO PBZ Products Affected by These Changes

Product Name	WMO Header	AWIPS ID
Special Weather Statement	WWUS81 KPBZ	SPSPBZ
Zone Forecast Product	FPUS51 KPBZ	ZFPPBZ
Hazardous Weather Outlook	FLUS41 KPBZ	HWOPBZ
Non-Precipitation Watch/Warning/Advisory	WWUS71 KPBZ	NPWPBZ
Winter Weather Watch/Warning/Advisory	WWUS41 KPBZ	WSWPBZ
Area Forecast Matrices	FOUS51 KPBZ	AFMPBZ
Point Forecast Matrices	FOUS51 KPBZ	PFMPBZ
Flood Watch/Warning/Advisory	WGUS61 KPBZ	FFAPBZ
Hydrologic Outlook	FGUS71 KPBZ	ESFPBZ
Hydrologic Statement	FGUS81 KPBZ	RVSPBZ
Hydrologic Summary	SRUS41 KPBZ	RVAPBZ
Daily River and Lake Summary	FGUS51 KPBZ	RVDPBZ
Public Information Statement	NOUS41 KPBZ	PNSPBZ
Area Forecast Discussion	FXUS61 KPBZ	AFDPBZ
Air Quality Alert	AEUS71 KPBZ	AQAPBZ

If you are affected by these changes, take the appropriate action so your system(s) recognize the new zone (Z) Universal Geographic Codes (UGC) and the new zone alignments.

Shape Files

Updated public and fire zone map shapefiles are available for download at: https://www.weather.gov/gis/PublicZones

The proposed changes to the PBZ zone boundaries have been closely coordinated with local partners and customers to be ready for implementation on March 8th, 2023.

If you have any questions concerning this change, please contact:

Fred McMullen

Warning Coordination Meteorologist

National Weather Service Pittsburgh

192 Shafer Road

Moon Twp PA 15108

412-262-1591