306
FXUS64 KJAN 021734 AAC
AFDJAN

Area Forecast Discussion...UPDATED
National Weather Service Jackson MS
1234 PM CDT Thu May 2 2024

...New AVIATION...

.MESOSCALE UPDATE...
Issued at 1016 AM CDT Thu May 2 2024

Another challenging and complex forecast for the near term with
poor guidance due to the meso-scale nature of the sensible
weather. Morning analysis shows a warm frontal type feature across
our S to W parts of the cwa, basically this is the mark of the
better low level moisture return. This feature gets more messy as
you go westward as we have a MCS established and has modified the
boundary across SW LA into E TX due to convective outflow/cold
pool evolution. Per 12z JAN raob analysis, moisture depth is
rather low and we have poor lapse rates along with 3 noted
inversion layers through 400 mb. Saying this, our forecast area
will need much higher moisture advection to occur to support
deep/strong convection along with an increase in stronger flow.
This doesn`t appear to occur today and this is being realized by
the MCS weakening as it propagates eastward. Hi-res guidance
showed this evolution (despite errors in timing/location) for this
morning into the afternoon with a weakening/decaying MCS. The
quality lower level moisture advection is not really moving into
the area from S LA as this area is generally limited in the 850mb
theta-e. The best 850 theta-e air is back west across S and
Central TX and if feeding into the back side of the decaying MCS.
This configuration will only really support better storm activity
well to our west. Due to these limiting factors, sever storm
potential over our forecast area looks to be quite low and less
than the advertised Marginal Risk. We will be collaborating to
make adjustments this morning after more assessment from the 12z
CAM guidance.

The next main forecast challenge for today into tonight will be PoPs
and weather. Will do my best to capture the timing of activity
today, but much of the area will be moisture starved by later
afternoon/evening and feel rain activity will be much harder to come
by. The early take on the 12z CAMs supports much lesser rain chances
for tonight...and if this holds, we will need to lower PoPs quite a
bit. So, look for the forecast to be an evolving one to best capture
trends. More info to come with the afternoon forecast package.  /CME/

&&

.DISCUSSION...
Issued at 401 AM CDT Thu May 2 2024

Today and Tonight: Continued warmer than normal through
tonight despite an increase in cloud over and rain chances.

Early morning surface analysis still had a ridge nosing into our CWA
from the east. This was resulting in a southeast to south wind that
was continuing to increase low level moisture back across our
region. This moisture increase has led to the development of patchy
dense fog and stratus across our southeast that is expected to
increase in coverage across our south this morning. A Dense Fog
Advisory is in effect until 9AM for the area along and south of a
line from Laurel to Brookhaven where visibilities less than a
quarter mile are likely.  Regional radars were already lit up this
morning with an area of convection over east Texas. A split flow
regime will continue with the southern branch across the Gulf coast
states. A disturbance within the southern branch will help drive
this convection east today into our CWA. Model consensus suggests
the convection will develop into a bowing line as it moves into our
CWA during the heat of the day. The primary threat will be damaging
wind gusts but hail to quarter size and a brief tornado our two will
also be possible. Although isolated severe storms will be possible
as far north as Cleveland the main area looks to be along and south
of Interstate 20 and mainly during the afternoon into early evening.
Locally heavy rainfall may also lead to some runoff issues in the
typically poor drainage areas. The severe storm threat will end
early this evening but rain chances will continue through the night
as a cold front approaches from the northwest. /22/

Friday through next Thursday...

By Friday morning, rain chances look to stick around as a weak
shortwave allows a boundary to hang up across central MS just north
of a high pressure in the off of the MS coast. This will keep higher
rain chances in the forecast through late Friday afternoon.
Scattered to numerous showers and storms are expected across central
and northern Mississippi on Friday. Rain chances are expected to
decrease by the late evening into the overnight period. By the
weekend, low level southerly flow paired with a series of week
shortwaves moving through the region will keep scattered to isolated
rain chances in the forecast through Monday. Highs will remain in
the lower to middle 80s through the weekend.

By Monday, surface ridging will amplify over the southeast CONUS,
bringing drier and warmer air into the ArkLaMiss. Southwest flow
will keep the moisture at bay going into the new work week.
Additionally, increasing heights will bring our first dose of summer-
like temperatures into the region. Highs are expected to climb into
the upper 80s to low 90s by mid-week. The next chance of rain looks
to be north of the hwy 82 corridor by late week, but guidance is
a bit uncertain on specifics as of now. /AJ/

&&

.AVIATION...
(18Z TAFS)
Issued at 1230 PM CDT Thu May 2 2024

Decaying storm complex (rain area) continues to dissipate this
midday and thus, really no restrictions in the official TAF in the
next 6-12 hrs. Once we get into the 06-09z window, look for some
lower ceilings to develop. MVFR will start, then some areas will
lower to IFR for the 10-14z window. Some vis reduction may exist
with the IFR ceilings but the flight category is covered. /CME/

&&

.PRELIMINARY POINT TEMPS/POPS...
Jackson       85  68  80  64 /  60  50  60  30
Meridian      88  66  84  64 /  30  40  50  40
Vicksburg     83  68  79  65 /  70  50  70  30
Hattiesburg   88  67  84  65 /  30  40  40  20
Natchez       82  67  78  64 /  80  40  80  20
Greenville    84  69  78  66 /  60  80  80  40
Greenwood     87  68  79  65 /  40  80  70  40

&&

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

$$

CME/AJ/22