This study comprehensively compared between HRRRv4 forecasts data with situ observations in a small-sized city located in the semi-arid climate of US. The detailed validation conducted on a medium-sized city remote from mega cities is particularly noteworthy, especially the inclusion of verification for urban heat advection. However, the content of this paper, particularly the sections of introduction and discussion, requires revision to highlight the study's key findings and insights.

Major comments

(1) The study provides a valuable analysis of Lubbock. To broaden the implications, might the authors consider incorporating additional small-sized cities with different climate background?

(2) Given that this study primarily focuses on the evaluation of HRRR forecasts, a more comprehensive overview of previous validation studies concerning HRRR (or other high-resolution operational forecasts) within the introduction would strengthen the argument. At the same time, the reasons for evaluating forecasts rather than reanalysis products should be more clearly presented.

(3) Lines 62–77: The introduction of ULSM/UCM is too detailed. Such description may initially lead readers to assume that the paper is about developing or coupling a new UCM into NWP. A more appropriate focus would be on the limited assessment of slab models within operational forecasting.

(4) The focus on a small-sized city is an important contribution. To better highlight this value, the results and discussion could both include more explicit comparisons with validation results from large metropolitan areas. For example, how do the prediction errors of HRRRv4 forecasts data found in Lubbock differ (in quantitative terms) from errors reported in studies of large cities?

Minor

The acronym urban heat advection (UHA) is only defined in the abstract. Please also spell it out at its first occurrence in the introduction.

This study evaluates HRRRv4 forecasts against two observational networks in Lubbock, Texas: the dedicated U-HEAT deployed across the city, and the regional West Texas Mesonet. The U-HEAT dataset is a clear strength of the paper and provides a valuable basis and a detailed year-long assessment of systematic model biases. The inclusion of nocturnal cooling rates and urban heat advection in the evaluation is an important contribution as it extends the analysis beyond standard meteorological variables. The manuscript is well organised, with clear sections, and is relevant for both urban climate studies and operational forecasting applications. At the same time, certain aspects of the study could be clarified and extended to further strengthen the generalisability and reproducibility:



- Major comments:



1. Since the study is centred on a single mid-sized city in a semi-arid climate, it would strengthen the conclusions to discuss more explicitly how the identified biases might generalise to other small cities under different climatic conditions. A brief paragraph clarifying transferability across different climatic regimes would help readers gauge generalisability.

2. The evaluation of nocturnal cooling rates (Sect. 3.3) is informative, but is based on a subset of nights with continuous domain-wide cloud cover below 25% and statistically significant cooling (p<0.05) (Sect. 2.5). To assess robustness, it would help to report how many nights satisfy the cloud-cover filter and to briefly justify the chosen threshold at 25%.



- Minor comment:



The acronym UHA is introduced in the abstract but not defined at its first occurrence in the main text (Sect. 1, line 97). Please ensure that acronyms are consistently defined when first used in the manuscript.