Marine Weather and Tide Forecast for Guntersville, AL

NEAR TERM
(Rest of Today and Tonight)
Issued at 154 PM CDT Fri Oct 16 2026

There have been no changes to near term forecast reasoning since the update earlier this morning. A cold front continues to progress quickly southeastward across the TN Valley early this afternoon, and should exit our CWFA by 22Z (if not sooner).
Widespread low stratus clouds and NNW winds of 10-15 MPH (with gusts up to 20-30 MPH) will persist in the wake of the cold, although both sustained speeds and gusts should diminish a bit overnight. Conditions still appear favorable for the development of pockets of light stratiform from late this afternoon through this evening, and we will make no changes to POPs at this time (especially as a few showers may continue to impact the northeastern corner of the CWFA through early tomorrow morning).
Overnight lows appear on track to reach the m-u 40s.

Previous Discussion: Over the course of the near term period, a strong mid-level high (centered off the southeastern Atlantic Coast) will retreat eastward as an amplifying northern stream shortwave trough digs from the Upper MS Valley into the central/southern Appalachians.
In response to this, a deepening area of low pressure at the surface will advance east-northeastward across southern QC/northern New England and into the Gulf of St. Lawrence by the end of the period.

A cold front extending southwestward from the low will make steady southeastward progression across the local forecast area today, and after entering northwest AL ~14Z should exit our southeastern counties by ~22Z. In spite of limited instability (with ensemble MUCAPE less than 100 J/kg), sufficient boundary layer moisture should exist in the vicinity of the frontal confluence axis for the development of a thin line of low-topped convective showers as the front progresses across the region. As mid-level WSW flow increases to 70-80 knots and synoptic scale ascent strengthens this afternoon and evening downstream from the approaching 500-mb wave, one or more bands of light stratiform rain may also evolve within the postfrontal airmass, and we have made a minor increase in POPs region-wide within the 21-3Z timeframe to account for this scenario. In the wake of the cold front, surface winds will veer sharply to NNW and strengthen, with sustained speeds of 10-15 MPH and gusts up to 20-25 MPH (perhaps 25-30 MPH in a few locations) anticipated. This will quickly begin to advect a cooler/drier mixture of Canadian and modified North Pacific air into the region, with daily max temperatures dependent of timing of frontal passage (and related CAA/increase in cloud cover).

Although lingering light rain this evening (in the eastern portion of the CWFA) will likely end by 3Z, favorably oriented low-level streamlines may continue to generate a few oragraphically-induced showers across the northeastern half of the region through sunrise tomorrow. Due to the combination of widespread stratus clouds and a moderate NNW wind, overnight lows will generally be in the m-u 40s.

SHORT TERM
(Saturday through Sunday night)
Issued at 1045 AM CDT Fri Oct 16 2026

An amplifying northern stream shortwave trough (positioned to the immediate northeast of the local forecast area at the beginning of the period) is predicted to evolve into a weak low that will drift southeastward to the NC Coast by Sunday night as it becomes detached from the polar westerlies. As a low-amplitude mid-level ridge builds northeastward into the region (in the wake of this feature), strong NNW flow aloft will weaken considerably from Saturday night-Sunday night, and due to the dry nature of the airmass and absence of atmospheric lift, we expect dry conditions to prevail (in the wake of any lingering wrap-around showers early Saturday morning).

In the low-levels, a surface high will migrate northeastward from the southern High Plains into the Lower Great Lakes/OH Valley on Saturday (and into the northern Mid-Atlantic States Saturday night). This configuration will result in NNE winds (of similar magnitude to today) on Saturday, with flow diminishing and veering to ENE Saturday night. Regardless of sunny skies, afternoon highs tomorrow will range from the m-u 50s in elevated terrain to the l-m 60s in the valley. This will be followed by optimal conditions for radiational cooling on Saturday night, with lows in the u30s-l40s (away from large water sources). If winds become calm (which is unlikely based on the anticipated pressure gradient), forecast soundings suggest that dewpoint depressions will be sufficiently narrow to support the development of patchy frost in a few wind-sheltered locations across southern TN/northeast AL (where temps may fall into the mid 30s).

As the surface high shifts further northeastward into the northwestern Atlantic on Sunday/Sunday night, a lingering surface ridge axis will maintain a light easterly-calm wind across the region. Afternoon temperatures will rise a few degrees into the m-u 60s, with overnight lows Monday morning once again in the m30s-l40s.

LONG TERM
(Monday through Thursday)
Issued at 944 PM CDT Thu Oct 15 2026

High pressure will remain dominant during the long term period as upper ridging slowly pushes east during the middle of the week.
This will result in dry weather and gradually warmer temperatures with highs climbing back into the 70s on Monday then into the 80s on Thursday. We should see plenty of sunshine through the week and clear skies at night. While temperatures will rise back above seasonal norms, it will feel much more like fall compared to the record breaking heat we have seen recently.

AVIATION
(00Z TAFS)
Issued at 651 PM CDT Fri Oct 16 2026

VFR to MVFR conditions have prevailed across the area with a mid level stratus deck forecast to persist through the evening hours.
The back edge of this cloud deck can be seen moving into NW AL currently. While there may be some clearing behind this, additional MVFR cigs are forecast overnight and amendments may be necessary to account for satellite trends and observations.
Northerly winds will remain gusty in the wake of a cold front, and wind shear will increase near the KMSL terminal tonight. Have included northerly wind shear between 35-40kts at 2kft for KMSL through 15z tomorrow.

HUN WATCHES/WARNINGS/ADVISORIES
AL...None.
TN...None.