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Why a Desert Weather Station Linked NHC Tropical Activity

Why a Mesa-era desert PWS carried NHC Atlantic and East Pacific pages: remnants, moisture plumes, and education, not a live tropical warning service.

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A backyard station in Mesa, Arizona, is not a hurricane landfall site. It still had a reason to carry National Hurricane Center (NHC) pages for the Atlantic and eastern North Pacific: remnants and moisture plumes can reach the Southwest, and tropical products are worth learning before a visitor needs them. TNET Weather is not a warning service. Live tropical activity belongs at nhc.noaa.gov. Local watches, warnings, and evacuation orders belong at weather.gov and with emergency management.

This article explains why a desert personal weather station (PWS) hosted those links. It is not a lesson in parsing a Hurricane Local Statement; that notebook is Reading an NWS Hurricane Statement.

Historical context

The recovered /hurricanes.php page sat next to hazards, radar, and NOAA-parse utilities on the historical TNET Weather site. Wayback material shows an NHC Atlantic heading, a season-date line, and a 2006 “NHC Feed Parser” credit. The parser, the feed, and any then-current storm list are not rehosted. A 2006 parser date is provenance for the page, not a statement about today’s storms.

Hobby templates of that decade often defaulted to the Atlantic basin because that is where U.S. landfall attention concentrates and where many public NHC widgets started. A Phoenix operator who left the Atlantic block in place was not claiming that Mesa sits on the Gulf coast. The same operator who also pointed at the eastern Pacific was doing the scientifically interesting job: that basin is the one that can actually wet the desert.

Two basins, two jobs

NHC is the U.S. authority for tropical cyclones in both the Atlantic and eastern Pacific basins. Season dates and mean activity are NHC climatology, not station lore (NHC tropical cyclone climatology; last checked 13 August 2026):

  • Atlantic (Atlantic Ocean, Caribbean Sea, and the Gulf): official season 1 June–30 November. For the 1991–2020 climate period, NHC cites an average of 14 named storms, 7 hurricanes, and 3 major hurricanes.
  • Eastern Pacific (from Mexico and Central America west to 140°W): official season 15 May–30 November. For the same climate period, NHC cites an average of 15 named storms, 8 hurricanes, and 4 major hurricanes.

A Mesa PWS that showed only the Atlantic was teaching a national product suite. A Mesa PWS that showed the eastern Pacific was teaching the basin that can send remnant moisture into Arizona. Showing both was coherent. Treating both as “hurricanes about to hit Phoenix” was not.

Central Pacific activity is a third NHC/CPHC problem and was not the historical function of this URL. Do not backfill it.

Why remnants and moisture plumes belong on a desert page

Tropical-cyclone winds collapse quickly over the mountains and deserts of northwest Mexico. Tropical moisture does not have to remain a named cyclone to matter. NWS Tucson’s tropical weather page states the operational climatology for southern Arizona (NWS Tucson: tropical weather; last checked 13 August 2026):

  • Since 1965, eight remnant tropical storms or hurricanes survived the overland trip well enough to affect southern Arizona as an intact tropical storm or depression.
  • In the same period, 17 other storms dissipated south or southwest of Arizona and still triggered flash flooding when remnant moisture spread into the state. NWS Tucson notes that four of the five most serious floods in southern Arizona since 1970 were caused by tropical-cyclone remnants.
  • Recurvature into the Southwest is most favored late in the North American monsoon, from late August into early October, when a mid-latitude trough can turn an eastern Pacific cyclone north instead of letting it die over open water.

Peer-reviewed remnant studies agree on the mechanism even when they count events differently. Ritchie, Wood, Gutzler, and White (2011) examined 43 eastern North Pacific remnants during 1992–2005 and found that 35 (81%) brought precipitation to some part of the southwestern United States; the rest were largely restricted to Mexico, sometimes with cloud cover still spreading north (Monthly Weather Review, doi:10.1175/2010MWR3389.1).

Those are historical and climatological statements. They are not a forecast that a remnant is approaching Arizona now. They are why a desert PWS kept an NHC East Pacific link in the same season it kept a monsoon rain gauge.

Separate three things that hobby pages often drew as one icon:

| Object | What it is | Who speaks for it | |---|---|---| | Named tropical cyclone | A classified system with NHC advisories, track, and intensity | NHC | | Post-tropical / remnant circulation | The cyclone as classified by NHC after it no longer meets tropical-cyclone criteria; inland rain and flood risk often continue | NHC until the last advisory; then NWS offices and the Weather Prediction Center | | Moisture plume without a named center | Tropical water vapor and rainfall in the monsoon environment, which may or may not be tagged to a remnant | Local NWS offices |

A PWS rain total in Mesa can be observed. It cannot tell you whether the water arrived as a remnant, as ordinary monsoon convection, or as a plume the office never attached to a cyclone name. That attribution is an official or research analysis, not a station derived index.

Education was a valid reason for the Atlantic block

Most visitors to a Phoenix weather site will never need an Atlantic Hurricane Local Statement for their own county. They will still meet tropical headlines on national media, family travel, and later, on any page that discusses weather evidence. Hosting NHC’s Atlantic page next to a desert dashboard was a literacy choice: here is the agency, here are the basins, here is where live activity lives.

That choice does not make the PWS an East Coast warning point. It also does not make TNET a replacement for NHC. The recovered parser credit is a reminder that stations consumed NHC text. They did not author it.

If you are teaching someone how to read an inland hurricane wind warning or a local statement—office, issuance versus valid time, headline as an operational flag—use the notebook at /nb-0001.php. This URL’s job is the prior question: why the desert site pointed at NHC at all.

What a station page should do instead of restyling NHC

  • Link NHC for current Atlantic and East Pacific activity. Do not scrape advisories into a TNET-branded ticker.
  • For Arizona impacts, send readers to the local office—NWS Phoenix for Greater Phoenix, NWS Tucson for southeast Arizona—and to weather.gov more generally.
  • Label any embedded NHC graphic with basin, advisory number, and advisory time in UTC. An undated cone is a cartoon.
  • Keep station rain, wind, and lightning in the observation column. Do not use a Mesa gust to “confirm” or “refute” an NHC wind radii chart.
  • After NHC writes a last advisory on a remnant, do not keep a storm-shaped icon on the PWS as if NHC were still issuing. Point at the Weather Prediction Center and the local NWS office for inland rainfall.

This URL does not display live tropical cyclones, tracks, or watches.

Safety boundary

If a tropical cyclone, remnant, or flood watch is in progress where you are, leave this article. Open NHC and NWS. Follow local emergency management. A historical explanation of why a desert PWS linked NHC is not an advisory.

How a PWS should link NWS watches, warnings, and advisories without competing with them is hazards.php.

Modern relevance

Tropical moisture, deep convection, and heavy rain are atmospheric evidence families. They are not a TNET tropical warning and they are not a promised change in connectivity. TNET’s public grouping of weather structure, precipitation, and related inputs is the evidence families behind a connection outlook. Use that page to see how TNET talks about evidence types. Use NHC for the storm.

Related: NWS products on a PWS, lightning as a local observation. Hub: historical observations.

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