Flash Flood Warning 26, NWS Jackson, MS

Area Forecast Discussion
National Weather Service Jackson MS
142 PM CDT Thu May 28 2026

...New DISCUSSION...

.KEY MESSAGES...

- Additional periods of heavy rainfall and flash flooding will be
  possible today.

&&

.DISCUSSION...
Issued at 138 PM CDT Thu May 28 2026

Through mid next week (Today through next Tuesday)...

Today into tonight: Perturbed flow/vorticity will drive increased
moist ascent and deep moisture (1.75 to 2.1 inch precipitable
water) into the southern areas this morning. There is continued
indications of a mesoscale convective vortex (MCV) that will lift
northward somewhere near the ArkLaTex region, potentially west of
the MS River. This will drive a stronger low-level jet, ascent
and convergence on a mesoscale level. This will be difficult to
pin down exact areas but our southwest areas have the best chances
of seeing enhanced rainfall rates due to this feature. Light
backbuilding flow and some enhanced cloud bearing flow (up to
20kts) will enhance rainfall totals in these areas. Based on that,
we decided to make some local adjustments to the HWO graphics to
hone in to a more refined zone of potential higher rainfall rates,
totals and flash flood concerns. This will generally be in the
Delta counties of west, southwest and southern MS, southeast AR
and northeast LA. Convective allowing models (CAMs) support this
idea. This HWO graphic will now be refined to just Thursday and
will be on a day-to-day basis but the current one will not include
Friday.

Afternoon convection will be generally scattered in coverage (45
to 65 percent). Highs will remain seasonable (mid 80s), with
seasonably warm lows this morning and again tonight (upper 60s to
low 70s). HREF probability match mean (PMMs) indicate another
round of neighborhood probs (10 percent) for receiving in excess
of 3 inches, with some higher totals in the HREF maximums. In
addition, there are some HREF dense fog probs both this morning
and again tonight, but confidence isn't high enough to add any
mention in the HWO but only in the weather grids at this time.

Friday through next Wednesday: As upper low over TX/OK Panhandle
lifts north, southerly flow will remain established but lighter
through the week. The region will remain in a longwave quasi-
omega block pattern into late week (upper low caught over the
Pacific states and developing longwave trough over the northeast
states into eastern Canada). However, this synoptic pattern
doesn't look as established as a typical omega block, with strong
subtropical ridging established over the western Atlantic
extending westward into the FL Peninsula. On the eastern periphery
of the western portion of the quasi-omega block the perturbed
energy/vort max will lift northward but some of the tail end of
the trough axis will slowly shift east across the region Friday.
This will keep light return flow, deep moisture and light
backbuilding flow into Friday. Rain coverage will remain high
Friday (45 to 80 percent daily) and becoming focused east of MS
River corridor Friday.

As the upper low lifts and trough axis shifts east across the Mid
South to Mid MS Valley into the weekend, shortwave ridging and
westerly flow will lock in, leading to less moist Gulf influence
and more scattered rain and storm coverage (35 to 65 percent
Saturday and Sunday). Highs remain seasonably cool this weekend
(low to upper 80s) while generally seasonably warm lows (upper 60s
to low 70s). Longer range pattern consists of surface high diving
into the Great Lakes and eventual drying front from the north.
However trends have slowed, with most relief in rain coverage
becoming more scattered next Monday to shifting southward and isolated
to scattered next Tuesday to Wednesday (20 to 40 percent).
Continued seasonable cool highs and less seasonably warm lows will
be the norm through the middle of next week. /DC/

&&

.AVIATION...
(18Z TAFS)
Issued at 1230 PM CDT Thu May 28 2026

Another round of showers/thunderstorms are expected to make their
way through the region today and may bring short-lived MVFR
ceilings. Once showers and thunderstorms die down around sunset
expect an anchoring of those lowered cloud decks and brief periods
of fog along our southern corridor. Tomorrow may bring another
smattering of thunderstorms/showers but less active than today,
which will bring the same conditions as today should that come to
fruition across the CWA./OAJ/

&&

.PRELIMINARY POINT TEMPS/POPS...
Jackson       70  85  69  87 /  20  70  40  40
Meridian      70  84  69  87 /  20  50  40  50
Vicksburg     69  85  70  88 /  20  50  30  30
Hattiesburg   70  85  69  88 /  20  50  30  40
Natchez       70  86  71  89 /  20  50  20  20
Greenville    70  84  70  87 /  60  50  20  20
Greenwood     70  84  70  87 /  50  60  40  40

&&

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

OAJ/OAJ/OAJ