Isaias and Rachel
Am looking at two tropical cyclones this morning that will likely have an impact on the United States. Isaias will likely intensify into a significant hurricane (probably at least a category 2 status) and impact a portion of the northern Gulf coast with heavy rain, damaging winds, and dangerous storm surge. Moisture from Isaias in combination with a northern stream system may produce significant rainfall across southern New England Sunday night into Monday. Rachel, or more precisely its remnants, may impact the Southwestern United States with flooding rains and gusty winds. Will discuss each storm in somewhat more detail below.
Isaias
Isaias was showing signs of deep and more organized convection this morning and is expected to intensify into a hurricane late today or tonight. This will be the first hurricane for this season in the Atlantic basin and the latest date of a first hurricane in the Atlantic basin on record! Isaias is in a rather favorable environment for strengthening due to very warm sea surface temperatures, a moist environment, and for now relatively light wind shear. Isaias will probably encounter increased wind shear as it nears landfall along the Gulf coast but probably not before it reaches at least category 2 status. A few skillful intensity models bring the hurricane to category 3 (major) status as it approaches the Gulf coast. Isaias was currently moving to the ENE this morning. However, the storm will turn toward the northeast and north in the next couple of days as it comes under the influence of an approaching upper-level trough that sharpens over Texas to its west and a building ridge to its east. Isaias will likely make landfall somewhere between New Orleans and Pensacola Friday evening. Interestingly, the AI models are toward the eastern portion of that track envelope, and the physics-based models are clustered toward the western portion.
The effects of Isaias are likely to be felt along the central Gulf coast by Thursday night and increase during the day on Friday. For impacts, the strongest winds and highest storm surge should be expected along and to the right of the hurricane’s path. Most at risk for damaging winds and life-threatening storm surge looks to be along the far southeast Louisiana, Mississippi, Alabama, and Florida panhandle coastlines (perhaps even as far east as the Big Bend area of Florida). Heavy rainfall with potential flash flooding will exist across Louisiana, southern Mississippi, southern Alabama, and the Florida panhandle. A Hurricane Watch will likely be issued for a portion of the central Gulf coast later today.
After Isaias makes landfall, it should weaken fairly quickly late Friday night or early Saturday morning. The moisture-laden remnants of Isaias will move north along or a little east of the Mississippi Valley and then turn to the east along the Ohio Valley as the remnants interact with a northern stream upper trough. Those remnants are then expected to be embedded in an extratropical surface low pressure center that eventually passes along or a little south of the New England south coast late in the holiday weekend. Although the timing could change a little, there is a fairly high chance of significant rainfall across much of southern New England during Sunday night into Monday.
Rachel
At first glance, Rachel looks like it’s headed far offshore into the east central Pacific. However, a fairly high amplitude upper-level trough approaching the United States west coast will likely interact with Rachel and cause a sharp turn to the northeast. The consensus of models brings a weakening Rachel toward northern Baja California or southern California this coming weekend. Rachel will undoubtedly weaken as it approaches land due to cooler sea surface temperatures and vertical wind shear associated with that upper trough. Nevertheless, a weakened Rachel or more likely the remnants of Rachel may threaten areas of the Southwestern United States with heavy rain, flash flooding, and gusty winds.
Next Message
Will issue a follow-up message Thursday morning on both storms. Note: The author will be hiking in the White Mountains on Friday and so probably no blog update on that day. Interests should refer to the latest Advisories from the National Hurricane Center and applicable local National Weather Service forecasts/warnings for these storms.
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The National Weather Service monitors the weather 24/7 and updates forecasts, watches, and warnings as necessary. For most of southern New England, refer to your local Weather Forecast Office for the latest forecast/warning information at weather.gov/box. For information from other Weather Forecast Offices, go to weather.gov and click on the location of interest on the map. For the latest advisories on tropical cyclones, go to the National Hurricane Center.
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Message issued October 7, 2026 by:
Bob Thompson
Retired National Weather Service Meteorologist
Blue Hill Observatory and Science Center Advisory Council member
