Marine Weather and Tide Forecast for Columbus, MS

MESOSCALE UPDATE
Issued at 1157 AM CDT Sun May 17 2026

Rest of today and tonight...

The region remains on the western periphery of subtropical ridging to the east and mean troughing gradually deepening over the Intermountain West to Pacific Northwest into mid to late Sunday. With warm/moist advection (thermal profiles at 850mb in the mid to upper teens and PWs climbing to 1.5 to 2 inches), an increase in cloud coverage and some rain chances will be possible across southwest MS and northeast LA this afternoon into early evening. Seasonable warmth is expected today, some 4F to 8F above (highs: 85F to 91F). Thermodynamic parameters remain sufficient (7.0 to 7.5 deg C mid level lapse rates;25C to 28C vertical totals; MLCAPE (1000-1500J/kg) and SBCAPE (1500-2500J/kg). There is some weak deep shear (20 to 35kts) that could support some strong to isolated severe storms in southwest MS into northeast LA on Sunday afternoon to evening. In conjunction with Storm Prediction Center (SPC), added a Marginal in portions of southwest MS, northeast LA and southeast AR. Hazards are damaging wind gusts and hail up to quarter size. This has the setup of a typical diurnal summertime pulse storms/microbursts.

Return flow of low level moisture will bring some low clouds and visibility reductions, but dense fog is unlikely as HRRR dense fog probabilities remain low. Holding off any mention in the HWO.
Forecast and HWO updates were shipped out earlier. Lows will be seasonably warm, some 10F to 15F above (65F to 69F east of I-55 to 70F to 73F along and west of I-55). /DC/

DISCUSSION
Issued at 128 PM CDT Sun May 17 2026

Through the work week (Monday through Friday)...

Cold core low, developing over the Four Corners, will eject into the northern Plains to Great Lakes and into Canada and Hudson Bay region. Persistent seasonable warmth (4F to 8F above and highs in 86F to 91F) and moisture (forecasts of 1.5 to 2 inches and GOES East satellite derived PWs generally similar) will be the norm.
Summertime pattern is on tap, with scattered rain and storm currently developing and later coverage (20 to 50 percent) and increased heat and humidity. With some steep lapse rates (vertical totals near 27C to 29C), some strong to isolated severe cannot be ruled out into early to mid week (as early as Monday but most likely Tuesday into Wednesday). There is an ongoing Marginal outlook for northwest to northern areas in the Hwy 82 corridor Tuesday afternoon to evening. There is support of diurnal microburst potential and pulse severe but deep flow/bulk shear will be light and variable and storm organization mostly driven by storms that are favorably oriented low level bulk shear.

As a stronger wave swings into the Great Lakes and surface low ejects into eastern Canada (995mb to 1000mb), front will shift south southeast towards the Gulf states. A southern stream shortwave will enhance upper diffluence, increasing ascent and moisture advection. This will drive higher coverage of rain and storms (45 to 90 percent Wednesday and 55 to 75 percent on Thursday).High temperatures will be seasonable, with lows less seasonable, falling from 8F to 12F above (upper 60s to low 70s west) to 4F to 8F above (mid to upper 60s). With less seasonable temperatures, humidity and lapse rates, some stronger storms are likely and marginally severe storms remain possible. Mid to deep layer bulk shear will remain sufficient (around 30kts), with low level shear around 15-25kts. This will keep potential marginally severe concerns through the remainder of the work week (Wednesday through Friday). Rain totals for the week will be around a couple of inches (1 to 3 inches), which will help lessen some long term drought concerns. /DC/

AVIATION
(18Z TAFS)
Issued at 1256 PM CDT Sun May 17 2026

VFR conditions will prevail until after 08Z when MVFR/IFR CIGs likely develop across southern sites, persisting until after 14Z.
Winds will generally be out of the south 5-10 kts with gusts 15-20 kts possible after 16Z Monday. Intermittent TSRA/SHRA will be possible at HEZ and from 22z through 01Z. /86/

PRELIMINARY POINT TEMPS/POPS
Jackson 70 88 72 88 / 10 10 0 50 Meridian 65 88 69 89 / 0 20 0 10 Vicksburg 71 89 72 89 / 10 20 10 30 Hattiesburg 67 88 70 89 / 0 30 0 20 Natchez 73 89 73 90 / 10 20 10 40 Greenville 72 90 73 91 / 20 10 20 30 Greenwood 72 89 73 90 / 10 10 10 30

JAN WATCHES/WARNINGS/ADVISORIES
MS...None.
LA...None.
AR...None.