A trough of low pressure currently located inland over northeastern Mexico is expected to move near the northwestern Gulf Coast this week, and may barely emerge offshore, where development of a weak tropical cyclone is possible. The disturbance, designated Invest 90L by the National Hurricane Center (NHC) this afternoon, is a serious rainfall threat for much of the western and central Gulf Coast.

As of 18:00 UTC (2:00 p.m. EDT) Monday, Invest 90L was centered near 26.0°N 101.0°W. Maximum sustained winds were 15 knots (15 mph), with an estimated minimum pressure of 1011 mb. 90L is the first “invest” – short for area of investigation – of the 2026 Atlantic hurricane season. The NHC currently gives 90L a 40 percent chance of development within 48 hours, and a 50 percent chance within 7 days. If 90L becomes a tropical storm with sustained winds of at least 39 mph, it will be named Arthur. The center of 90L is expected to pass near the central Texas coast or move slightly offshore, where a more defined area of low pressure may form Tuesday night or Wednesday morning. An Air Force Hurricane Hunter aircraft is scheduled to investigate 90L tomorrow, if necessary.

Widespread rainfall totals of more than 5 inches are possible from southeastern Texas eastward to Alabama, with isolated totals of up to 10 inches possible. While parts of this region are currently experiencing drought conditions, the potential heavy rainfall totals make 90L a serious flooding threat for much of the northern Gulf Coast despite it not expected to become a significant tropical cyclone.