NOAA National Weather Service

Implementing a New Mixing-Length Constraint in Operational HAFS v2.2 Upgrade: Impacts on Tropical Cyclone Intensity Forecast

This study introduces a physics-based dynamic constraint for the asymptotic allowable mixing length, implemented in the latest upgrade of NOAA’s operational Hurricane Analysis and Forecast System (HAFS) v2.2. Replacing conventional fixed-value caps, the new constraint varies as a...

Taiwan area heavy rain observation and prediction experiment (TAHOPE): overview and some scientific results

Abstract “Taiwan Area Heavy rain Observation and Prediction Experiment” (TAHOPE) was originally planned to be conducted from August 2019 to July 2022 to study Mei-Yu fronts, mesoscale convective systems (MCSs), landfalling typhoons and afternoon thunderstorms near Taiwan. The Pre...

Case Study: Effectively Communicating Modeling Uncertainty to Communities Affected by Cryospheric Hazards – A Look at Interdisciplinary Collaboration Regarding Mendenhall Glacier Lake Outburst Floods in Juneau, Alaska

Cryospheric hazards are natural phenomena that are highly sensitive to climate change impacts and can have devastating impacts on surrounding communities. The rate of glacial change and loss under climate change is unprecedented and can result in more severe glacial hazards globa...

Shallow Landslides Align With Atmospheric Rivers in Coastal Steeplands

Abstract Rapid, shallow landslides in coastal mountains are triggered by extreme precipitation, shaping topography and impacting human settlements. Using an inventory of >700 landslides mapped from satellite imagery (2009–2024) and an atmospheric river database (1981–2019), this...

Dependence of Hurricane Track Forecasts on the Spectral Representation of Cumulus Convection

This study investigates the sensitivity of hurricane track and intensity forecasts to various cumulus parameterization schemes with scale-awareness, including the Simplified Arakawa-Schubert (SAS), Relaxed Arakawa-Schubert (RAS), and Chikira-Sugiyama Arakawa-Wu (CSAW), within the...

Impact of TRITON GNSS-R wind speed assimilation on convective rainfall prediction: a case study of a nearshore rainfall event on April 23, 2024

Abstract The TRITON satellite, developed by the Taiwan Space Agency (TASA) and launched in October 2023, is equipped with a global navigation satellite system (GNSS) reflectometry receiver and operates in a high-inclination orbit. The ocean surface wind speed (OSW) is retrieved f...