Final answer:
The stronger horizontal pressure gradients inferred from closely spaced isobars were located in the northeastern U.S., indicating stronger winds and possibly more severe weather. Another robust pressure gradient is noted in the northwest, also implying significant wind speeds.
Step-by-step explanation:
The stronger horizontal pressure gradients were located in the northeastern U.S., and another relatively strong horizontal pressure gradient can be found in the northwest corner of the map area. When looking at a weather map, isobars that are closely spaced indicate a strong horizontal pressure gradient. In the northeastern low-pressure area, we would typically see more closely spaced isobars compared to a southeastern high-pressure area, implying stronger winds and possibly more severe weather in the Northeast. Conversely, the more widely spaced isobars across the southeastern High suggest weaker gradients and, typically, calmer weather conditions.
The reference to the northwest corner of the map also indicates a location with another strong pressure gradient due to the proximity of the isobars, which may lead to significant wind speeds and distinctive weather patterns there as well. Differential heating, geography, and upper-level wind patterns contribute to these varying pressure gradients across different regions of the United States.