Marine Weather and Tide Forecast for Jonesville, VA

DISCUSSION
Issued at 254 AM EDT Sat Apr 18 2026

Currently, a trough/upper jet is centered to our northwest with a surface low moving into Ontario, Canada. This setup has produced a broad warm sector and large-scale severe weather event with a cold front extending along and west of the Mississippi River. This cold front will approach the area throughout the day today with increasing southerly flow out ahead. Showers and storms, some discrete, are expected during the evening hours ahead of this front.
The focus for strong to marginally severe storms continues to be in the northern half of the region where MLCAPE of near 1,000 J/kg is suggested due to better height falls. While stronger flow is expected aloft, 850mb winds will remain generally 30 kts or less with limited low-level shear. CAPE within the -10 to -30 Celsius region is indicated to be near 400 J/kg with WBZ heights around 10,000 feet. This continues to suggest low-end threats for damaging winds and hail, as shown in the outlook. The cold front will move through the area after midnight, leading to decreasing rain coverage.

Throughout the day on Sunday, the cold front will have pushed well off to the east with high pressure expanding from the southwest.
This will lead to cooler and drier conditions with high temperatures remaining in the 60s for most. Low RH's in the 20s will come back into view, along with northwesterly winds. Sunday night will be notably cooler following recent subsidence with some places dropping into the 30s. By Monday, high pressure will be centered nearby, leading to a weaker MSLP gradient/winds but continued dry conditions. Even cooler low temperatures can be expected Monday night, potentially cold enough for frost in some areas. By Tuesday, recent troughing and surface high pressure will shift off to the east, producing a shift to southerly flow and height rises. This will begin another warming trend with highs rising back above normal. Ridging will lead to further height rises through the end of the week with most places rising back into the 80s. Low RH's will continue to be of concern with generally southerly to southwesterly flow. With a fairly weak MSLP gradient and 850mb flow, wind gusts will be generally 15 to 20 mph or less for most areas.

AVIATION
(06Z TAFS)
Issued at 151 AM EDT Sat Apr 18 2026

VFR and dry can generally be expected for the first three quarters of the TAF period. SW winds will increase out ahead of a frontal passage later this morning and afternoon. Gusts up to 25KT possible at TYS.

Wx and wind direction change expected around the last 6 hours of the TAF. Wind direction to eventually turn out of the NW. Showers with the front will approach and cross the area this evening and part of the overnight hours. Low chances for TS, so do not have anything mentioned, although it's a non zero chance. Degradation to MVFR CIG and VSBY possible with the front.

PRELIMINARY POINT TEMPS/POPS
Chattanooga Airport, TN 88 48 69 43 / 20 90 10 0 Knoxville McGhee Tyson Airport, TN 85 47 64 43 / 20 90 10 0 Oak Ridge, TN 85 45 66 42 / 40 90 10 0 Tri Cities Airport, TN 84 45 61 39 / 20 90 20 0

MRX WATCHES/WARNINGS/ADVISORIES
NC...NONE.
TN...NONE.
VA...NONE.