INDY_AMS

Indiana Chapter of the American Meteorological Society
E-mail & Google Chat: [email protected]
Membership Application:

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🔎 What happens when significant weather threatens Indiana?

Join Indiana AMS Sept. 30 for an inside look at the State Emergency Operations Center, plus chapter discussion and Q&A.

Join the chapter: https://t.co/Wi1lrM0Qpr

#IndianaAMS #Meteorology #EmergencyManagement

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📊 Strong El Niños generally tilt winter precipitation odds wetter in California and across the southern U.S., with drier odds across much of the northern U.S.

But every El Niño is different. 1982–83, 1997–98 & 2015–16 show why probabilities aren't guarantees. #IndianaAMS #ENSO

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🌊 ENSO strength is measured by tropical sea-surface temperature anomalies, not by the severity of its impacts.

The current RONI forecast peaks in Oct–Dec 2026, but U.S. impacts typically lag, with the highest odds during winter and early spring. #IndianaAMS #ElNino

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El Niño doesn't cause individual weather events. It changes large-scale atmospheric circulation, shifting the odds toward certain weather patterns over weeks to months.

Think of El Niño as changing the odds, not dictating the outcome. #IndianaAMS #ENSO

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🛰️ Ever seen the GOES “Cookie Monster”? During spring & autumn eclipse seasons, the Sun can enter ABI’s field of view. Solar Avoidance protects the instrument, but can leave chunks missing from imagery and affect data quality. #IndianaAMS #GOES

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🔄 𝗨𝗣𝗗𝗔𝗧𝗘:  NOAA/NWS has delayed implementation of the new RRFS and REFS forecast systems.

The new implementation date is Oct. 14, 2026.  RRFS/REFS will replace the NAM, HREF, SREF & HiresW.

Video: RRFS Composite Reflectivity

#NWS #meteorology #IndianaAMS

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𝗡𝗢𝗔𝗔𝗣𝗼𝗿𝘁 𝘂𝘀𝗲𝗿𝘀: The NWS is seeking comments through Sept. 21, 2026.

Feedback: https://t.co/9RSfTuhbU8

Official notice: https://t.co/XAqwFMmxfg

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📡 A significant change is coming to the infrastructure behind NOAA weather data.

The NWS plans to retire the satellite-based Satellite Broadcast Network (SBN), commonly known as NOAAPort, as early as Aug. 31, 2027.

#IndianaAMS

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NOAAPort distributes NOAA weather data, including satellite, radar & model data, to users across the Weather Enterprise.

The NWS is developing alternative data sources and wants input from current NOAAPort users.

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𝗬𝗼𝘂 𝗱𝗼𝗻’𝘁 𝗻𝗲𝗲𝗱 𝗮 𝗺𝗲𝘁𝗲𝗼𝗿𝗼𝗹𝗼𝗴𝘆 𝗱𝗲𝗴𝗿𝗲𝗲 𝘁𝗼 𝗴𝗲𝘁 𝗶𝗻𝘃𝗼𝗹𝘃𝗲𝗱 𝘄𝗶𝘁𝗵 𝗔𝗠𝗦! Many boards/committees have no degree requirement. Volunteer, present at conferences or contribute in other ways! https://t.co/Gmi06pqHbU… #IndianaAMS #AMS #Weather

[INDY_AMS @indy_ams]

Atmospheric rivers also transport heat. A warmer atmosphere can hold ~𝟳% more water vapor per °C, allowing these systems to carry more moisture. How their tracks and reach will change is less certain.

🔗 https://t.co/47J2dCXkiE

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🌧️ #AtmosphericRivers #INwx

Atmospheric rivers are narrow corridors of strong winds & concentrated water vapor. They can stretch thousands of km across oceans and transport 𝟮–𝟯× the water flow of the Amazon River. Typically, 3–5 exist in each hemisphere.

#INwx #IndianaAMS

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They transport vital moisture, but something must lift that moisture to produce heavy precipitation. In Indiana, fronts, low-pressure systems & thunderstorms can wring huge amounts of water from the air, sometimes producing flash flooding.

[INDY_AMS @indy_ams]

🔥 Wildfire smoke doesn't affect visibility—it can contribute to ground-level ozone far downwind.

A new study finds U.S. ozone levels began rising after 2015, reversing decades of progress. Wildfire emissions are a major factor, including across the Midwest.

#IndianaAMS #INwx

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If you live in a mobile/manufactured-home community, encourage the community leaders to construct a storm shelter if it doesn't have one, especially if other substantial shelter is unreasonably far away.

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A recent Delaware tornado highlighted a problem for people living in mobile/manufactured homes: What to do when a tornado warning tells you to seek shelter, but your home itself isn't a safe place to ride it out?

The August 20 Dover tornado was rated EF-1.
#INwx #TornadoSafety

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For mobile/manufactured-home residents, the safest plan is to have access to a sturdier building or designated storm shelter BEFORE severe weather threatens.

Talk with your household and mobile-home community about where you will shelter, and how you will get there.

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The longer pollution remains in the atmosphere, the more opportunity it has to negatively affect people and the environment.

These findings could improve modeling of smoke transport, air quality and cloud formation.

Read the study: https://t.co/4vtFOLD0JM

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🌫️ Why might organic aerosol persist longer than expected?

Purdue researchers found that molecules in smoke and urban haze can interact, reducing their apparent volatility—a “matrix effect” that can increase aerosol persistence.

#IndianaAMS #INwx