186
FXUS64 KJAN 191527 AAB
AFDJAN

Area Forecast Discussion...UPDATED
National Weather Service Jackson MS
927 AM CST Sun Jan 19 2025

...New MESOSCALE UPDATE...

.MESOSCALE UPDATE...
Issued at 927 AM CST Sun Jan 19 2025

Strong cold advection is ongoing this morning and will continue
through the day as an Arctic airmass continues to move into the
region. This, combined with lingering low stratus clouds will
limit insolation today. High temps will struggle to reach 40
degrees across most of the area, and with gusty NW wind, wind
chills will remain in the 20s across much of the area. Within the
thicker stratus deck, a few snow flurries are occurring across
northeast MS this morning. These will not be substantial enough
for accumulations, but they will remain possible in that area
through around early afternoon. /DL/

&&

.DISCUSSION...
Issued at 316 AM CST Sun Jan 19 2025

Today and tonight ...

Much colder today as an Arctic airmass moves into the area. While
strong cold air advection will serve to reduce cloud cover into this
afternoon and tonight, remaining low stratus could squeeze out any
remaining moisture in the column. With temperatures beginning the
day below freezing for most, we could see a snowflake or two in some
areas north of I-20. Any isolated and brief snow flurry would yield
no noticeable affect on visibility nor present any hazard, but would
be an interesting novelty for the area.

Highs will be much cooler today, topping out in the 30s/40s north to
south. Clearing skies heading into tonight will allow temperatures
to fall into the mid teens north of I-20 and to around 20 to the
south. This will result in wind chills in the 5-10 F range across
the area and has prompted the issuance of a cold weather advisory
for the entire area that will extend into the longer range period,
valid from 6 PM tonight through 9 AM Thursday. /86/

Monday through Tuesday Night...

There is nothing significant to really mention for Monday, beyond
the disparate ingredients for an approaching winter storm beginning
to coalesce upstream. Northerly flow will have taken root across the
region allowing for robust cold air advection and by extension cold
air to entrench itself across the deep south. This will set the
stage for an open northerly channel that a reinforcing Arctic
airmass will soon take advantage of. Lows Monday night will be
around 20F for the majority of forecast sites with areas of
efficient drainage or high elevation will range in the high teens.
Brisk overnight northerly winds will prevail which will inhibit
total decoupling ahead of a >1036mb high centered over the central
Plains making its way into the CWA around midnight.

The upstream surface high will continue shifting east Monday while a
northern stream shortwave trough drops out of the northern Plains. A
southern stream disturbance will help develop a surface low near the
southeast Texas coast. Monday night as the northern stream shortwave
drops temperatures back into the lower 20s, precipitation associated
with the developing low in the Gulf will spread north into the
southern portions of our CWA. Considering the frigid temperatures
through the atmosphere over our CWA, light snow is expected to
develop after midnight Monday night. Any wintry precipitation will
likely stick on surfaces and begin create hazards across our CWA.
The upper level trough will swing across our region Tuesday while
the surface low will track east across the Gulf. This is expected to
result in significant snowfall across much of our CWA Tuesday and
Tuesday night. The Highway 82 corridor will see the least
significant impacts from this event, with areas seeing either a
dusting or no snow at all. Along the I-20 corridor and extending
northwards about 50 miles expect a dusting and totals of up to an
inch or two. The greatest snow amounts; perhaps in excess of four
inches, will be possible across our Highway 84 corridor. Snow will
taper off from west to east late Tuesday night as both the trough
axis and surface low shift east of Mississippi.

Wednesday through Saturday...

High and dry for mid to late next week; variable winds, mostly clear
skies and no precipitation/hydrometeors are expected. The greatest
cause for concern will be our dangerously cold wind chills in the
wake of this Arctic outbreak/winter storm. Overnight wind chills are
not projected to break 20F until Friday, so prepare to bundle up at
night! Daytime temperatures are forecast to top out in the mid 40s
across all forecast zones. Generally speaking localized geographic
affects like drainage and elevation will be washed out through late
next week as the Arctic regime dominates entirely.

Next Week...

On Sunday the 26th night will be the first night in a week with wind
chills above freezing across any of forecast sites, with areas along
and west of the Mississippi seeing wind chills in the mid to upper
30s. The rebounding of our temperatures to more seasonal norms is in
response to the Arctic high dislodging from the deep south and
shifting eastwards off the coast of the Carolinas allowing for the
return of robust onshore flow. At this time it is expected that
minor perturbations will be moving through the mesoscale pattern,
providing just enough lift to see a slight chance of showers. This
far out we are erring on a more vague forecast for the precipitation
coverage and intensity, but given the overall pattern; no
significant impacts are expected to occur with these showers. /OAJ/

&&

.AVIATION...
(12Z TAFS)
Issued at 526 AM CST Sun Jan 19 2025

Low stratus will linger through the morning across much of the
area with ceilings improving after 18Z from MVFR/IFR to prevailing
VFR. Winds will remain northerly and gusty, as high as 25 kts at
times, diminishing after 00z. /86/

&&

.PRELIMINARY POINT TEMPS/POPS...
Jackson       38  20  38  22 /   0   0   0  20
Meridian      39  18  36  19 /   0   0   0  10
Vicksburg     39  20  37  22 /   0   0   0  20
Hattiesburg   44  21  41  22 /   0   0   0  10
Natchez       40  20  39  22 /   0   0   0  30
Greenville    35  19  31  22 /   0   0   0  10
Greenwood     35  17  34  20 /   0   0   0  10

&&

.JAN WATCHES/WARNINGS/ADVISORIES...
MS...Winter Storm Watch from late Monday night through Tuesday
     evening for MSZ042>066-072>074.

LA...Winter Storm Watch from late Monday night through Tuesday
     evening for LAZ015-016-023>026.

AR...None.
&&

$$

DL/86/OAJ