Area Forecast Discussion

KEY MESSAGES

Updated at 1032 AM CDT Mon Apr 20 2026

- Very dry conditions will start the new week. Afternoon relative humidities will be near 25 percent over portions of south Mississippi this afternoon.

- A warming trend will bring the area back to the mid 80s for highs by the end of the week along with the next chance of significant rainfall.

- Small Craft Advisories remain through this evening for northeasterly winds near 20 knots.

SHORT TERM

(Now through Tuesday) Issued at 1032 AM CDT Mon Apr 20 2026

Monday and Tuesday will be mostly dry overall as weak ridging builds in over the area. Conditions will remain cooler and drier on the backside of the front today and Tuesday. Relative humidities will be quite low (25-30%) across the area, but winds will ease off by the time the humidities are at the lowest. So, while conditions are dry, the winds will not be high enough to warrant any fire weather products. Onshore flow returns Monday night into Tuesday, bringing in humidities and warmer temperatures again. Highs Tuesday and Wednesday will be in the upper 70s and lows in the mid 50s to low 60s.

Wednesday, an upper level shortwave approaches the area, especially near the Atchafalaya Basin and areas west of I-55. There is very little forcing with this system, looking at the models. As a result, very little appreciable rain is expected with low PoPs (20-30%) for the Atchafalaya Basin and coastal Louisiana primarily due to isolated to scattered showers with some lighting possible. MSW

LONG TERM

(Tuesday night through Sunday) Issued at 1032 AM CDT Mon Apr 20 2026

Weak ridging builds back over the area Thursday, followed by zonal flow Friday through Saturday. Looking at the models, conditions will be mostly dry these days as a result. An isolated shower or two is possible Friday afternoon as zonal flow comes into play combined with the high moisture availability, but these storms would not have a ton of appreciable rainfall. Onshore southerly flow will help to advect warmer and more humid air into the region. As a result, temperatures will be warmer as the week progresses. Highs are forecast in the low to mid 80s, especially later in the week. Lows are forecast in the mid to upper 60s.

Sunday into Monday, a weak upper level impulse will move through the area, but there are still a lot of model uncertainties in this system. Initially, this system looks fairly weak overall with low rainfall amounts. But a lot of things can change in the next week, so we will keep monitoring closely. MSW

AVIATION

(18Z TAFS) Issued at 1032 AM CDT Mon Apr 20 2026

VFR conditions prevail at all area airports and will persist through the forecast period. Wind shifts greater than 30 degrees will be expected, especially late tonight, at all area airports. MSW

MARINE

Issued at 1032 AM CDT Mon Apr 20 2026

Northeast winds around 20 knots will remain rather gusty today, gradually becoming easterly on Tuesday. Small Craft Advisories remain in effect for these hazardous conditions today. By Wednesday, winds will shift to a more SE direction and ease a bit to around 10-15 kt, possibly remaining that way for the remainder of the week and into the next weekend.

LIX WATCHES / WARNINGS / ADVISORIES

LA...None. GM...Small Craft Advisory until noon CDT today for GMZ529-531>536-557.

Small Craft Advisory until 7 PM CDT this evening for GMZ541-543- 551-553-554-577.

Small Craft Advisory until 1 AM CDT Tuesday for GMZ570-572-575.

MS...None. GM...Small Craft Advisory until noon CDT today for GMZ531>536-557.

Small Craft Advisory until 7 PM CDT this evening for GMZ543-551- 553-554-577.

Small Craft Advisory until 1 AM CDT Tuesday for GMZ572-575.