Marine Weather and Tide Forecast for Slidell, LA

FXUS64 KLIX 210825 AFDLIX

Area Forecast Discussion National Weather Service New Orleans LA 325 AM CDT Mon Apr 21 2025

New SHORT TERM, LONG TERM, MARINE

SHORT TERM
(Today through Tuesday)
Issued at 320 AM CDT Mon Apr 21 2025

Upper ridging anchored off the Atlantic Coast this morning. A negatively tilted shortwave was moving through Iowa early this morning, with a secondary shortwave off the Texas coast. At the surface, low pressure over southwest Wisconsin had a frontal boundary southwestward to the ArkLaTex and then to the Rio Grande Valley. Radar and surface reports indicated a few light rain showers over southeast Louisiana and coastal Mississippi, although rain amounts weren't much more than barely wetting the ground in most places. Temperatures were between 70 and 75 early this morning with dew points between 68 and 71.

The upper ridge isn't going much of anywhere through Tuesday, although the shortwave near the Texas coast this morning will lift northeastward to near Charlotte by Tuesday evening. The frontal boundary to our northwest will gradually stretch out more east- west to our north over the next 36 hours, close to Interstate 20.
Precipitable water values that were around 1.3 inches Sunday evening will increase to about 1.6 this afternoon, which is around the 90th percentile climatologically for this time of year. Those moisture levels will remain in place through Tuesday afternoon.
It may take until afternoon today for moisture to become deep enough to produce anything more than light rain showers, though.

While instability is sufficient for thunderstorms, and lapse rates are sufficient, shear is lacking, generally 20 knots or less. With 500 mb temperatures around -13C, that would indicate some potential for hail. Cannot entirely rule out a few storms approaching severe limits this afternoon, mainly across northern and western portions of the area, closer to the frontal boundary.

While organized forcing may be lacking on Tuesday afternoon, convective temperatures may be a couple degrees lower. Over the next 36 hours, most areas should see at least some rain. If a location gets multiple storms, brief drainage issues are possible, but it's been almost 2 weeks since much of the local area has had any significant rainfall.

Temperature guidance is pretty consistent and major adjustments aren't necessary. Guidance lows may be a shade on the cool side, but probably not enough to chase.
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