506
FXUS64 KJAN 261132
AFDJAN

Area Forecast Discussion
National Weather Service Jackson MS
632 AM CDT Tue May 26 2026

...New AVIATION...

.KEY MESSAGES...

- Periods of heavy rainfall and flash flooding will be possible
  throughout this week.

&&

.DISCUSSION...
Issued at 158 AM CDT Tue May 26 2026

This week into weekend through early next week (Monday)...

Today into tonight: Upper low remains parked to our west, keeping
broad cyclonic/southerly return flow into the Gulf Coast states.
GOES east total precipitable water (PWs) indicate nearly 2 inch
PWs mainly east of the MS/AL border while around an inch and half
PWs or so along and west of the Interstate 55 and MS River
corridors. This is a result of less return flow air (generally
southeasterly flow around 850-700mb), but will gradually change
into the afternoon. As the upper low lifts northward, southerly
return flow will lock in the afternoon hours, leading to efficient
moist advection (PWs generally in the 1.75 to 2 inch range, 850mb
Theta E around 335K, strengthening cloud bearing layer flow in
the 850-300mb layer flow to around 30ks and light southwesterly
backbuilding vectors under 15kts). This pattern, combined with wet
antecedent conditions, lead to elevated flash flooding risk.
Neighborhood HREF PMMs (10 percent) for exceeding 3 inches and
HREF max values (3 to 5+ inch amounts in the Pine Belt), support
continued "Elevated" messaging in HWO graphics. Many convective
allowing models in the HREF suite, indicate reasonable rainfall
totals (1 to 3 inches) and worst case rainfall totals (3 to 5
inches). With recent rains and issues in this area and any
additional rain/MCV influence, messaging "Elevated" for flash
flooding in the HWO fits. Weather Prediction Center (WPC) has
continued to highlight a "Slight" risk for heavy rain, with higher
confidence of concerns in the Interstate 59 corridor that was hit
hard yesterday. Highs will be seasonably cool this afternoon (79F
to 82F in the Interstate 59 to Highway 45 corridors to 83F to 85F
to the northwest) while seasonably warm lows this morning and
again tonight (67F to 69F this morning and 68F to 72F tonight).
Rain chances remain highest (70 to 95 percent) southeast of the
Natchez Trace, while lower along and northwest (45 to 70 percent).

Wednesday through next Monday: As this upper low lifts northward,
there will be continued southerly flow but lighter through the
week. The region will be gradually caught in a longwave quasi-
omega block pattern into mid to 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 will be another
piece of perturbed energy/vort max that will cutoff over the TX
Panhandle Wednesday into Thursday. This will keep light return
flow but deep moisture near 2 inch PWs through late week. Rain
coverage will remain high through the work week (55 to 90 percent
daily) with some days on the higher end of the range than others.
Keeping a "Limited" going through the work week as wet antecedent
conditions and mesoscale features, such as local MCV influence,
will be need to be evaluated on a daily basis.

As the upper lifts and shears out across the Mid South to Mid
MS Valley into the weekend, westerly flow will lock in, leading to
less moist Gulf influence and more scattered rain and storm coverage
(45 to 80 percent Saturday and 35 to 55 percent Sunday). Highs
remain seasonably cool this week (low to mid 80s) while generally
seasonably warm lows (upper 60s to low 70s). Longer range pattern
may consist of surface high diving into the Great Lakes and eventual
drying front from the north, helping coverage to become more
scattered to isolated and continued seasonable cool conditions into
early next week. /DC/

&&

.AVIATION...
(12Z TAFS)
Issued at 610 AM CDT Tue May 26 2026

A mix of IFR/MVFR conditions prevail across TAF sites this
morning. Expect some improvement to mostly MVFR conditions later
this morning, but there will be increased chances of
showers/storms this afternoon./15/

&&

.PRELIMINARY POINT TEMPS/POPS...
Jackson       82  70  85  70 /  70  20  80  60
Meridian      80  70  85  70 /  80  30  80  50
Vicksburg     84  70  85  70 /  60  20  90  70
Hattiesburg   81  71  85  70 / 100  30  80  50
Natchez       84  71  85  71 /  70  30  80  70
Greenville    84  69  85  70 /  50  30  50  70
Greenwood     84  69  86  70 /  50  40  50  50

&&

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

$$

/15