546
FXUS64 KJAN 010152 AAB
AFDJAN

Area Forecast Discussion...UPDATED
National Weather Service Jackson MS
852 PM CDT Sun Jun 30 2024

...New MESOSCALE UPDATE...

.MESOSCALE UPDATE...
Issued at 851 PM CDT Sun Jun 30 2024

Late afternoon storm activity held on with this hot/humid airmass
in place and we`ve seen decent coverage into the initial part of
this evening. PoPs were adjusted earlier to account for more
activity and then show a downward trend from 02-04z with no
mention of precip after that. This looks to fit that trend well
and the only other adjustment for PoPs/weather will be needed once
activity is gone. Other changes were to temps as this was an
effort to chase the rain cooled air and outflows which were
lowering temps substantially. Lastly, the excessive heat warning
and heat advisory from today has expired. There`s an additional
one for Monday, but the area/orientation is quite different and
this is focused across the SW/S part of the forecast area. /CME/

&&

.DISCUSSION...
Issued at 241 PM CDT Sun Jun 30 2024

Tonight and tomorrow: A few showers and storms could linger past
sunset tonight, as a surface cold front pushes south across the
area. In the wake, dry air will bring some much needed relief from
the heat, albeit temporary. It`s not all good news for everybody
though, as areas south of I-20 hold onto mid to upper 70s
dewpoints. As such, a heat advisory has been continued in this
area for heat indices 105+. Showers and storms continue to be
possible tomorrow afternoon in far southern areas where moisture
remains abundant, but should be more isolated than this afternoon.
Heat makes a return mid week with upper ridging continuing to
build eastward./SAS/

Monday night through Saturday night: Come Monday evening a large
595dam ridge will be centered just west of our CWA while a >1020mb
centered over the Ohio valley ridges southwest across our CWA to a
stalled frontal boundary along the Gulf coast. A much drier airmass
with PWATs less than an inch and a half and surface dew points in
the 60s will be over the northeast third of our CWA. Tuesday looks
to be the hottest day of the forecast period as the large mid level
high becomes centered over our CWA. Most sites will top out in the
upper 90s. These temperatures combined with high humidity across our
southern zones will result in heat index values between 105F and
110F again so a continuation of a Heat Advisory is likely for our
southern zones Tuesday. Any daytime convection across our southern
zones is expected to have dissipated by evening so Tuesday night dry
weather is expected.

Wednesday through Friday the mid level ridge will weaken and flatten
over our region. The surface ridge will shift south and nose across
the Gulf coast from the east. This will help return low level
moisture and result in high humidity back across our whole CWA.
Afternoon highs will continue to be above normal and combine with
high humidity for heat index values above 105F each day. A Heat
Advisory will likely be needed for most of our CWA each day. As the
mid level ridge breaks down there will be a greater coverage of
diurnally driven convection each day as well. Saturday upper level
troughing from the west and perhaps a weak cold front will move over
our area. This will result in our next best chance for widespread
rain. The increased cloud cover and lower heights will also serve to
hold temperatures down a few degrees. /22/

&&

.AVIATION...
(00Z TAFS)
Issued at 633 PM CDT Sun Jun 30 2024

Generally quiet TAF period but over the next 1-2 hrs a couple
sites will be close to or get a brief SHRA/TSRA and I have a brief
mention of this. Beyond that, most of the night will be VFR. There
looks to be a small period between 12-16z where a corridor of MVFR
ceilings will exist early Monday ahead of a frontal boundary. I
have covered this with the latest TAF issuance. VFR will prevail
beyond 16z. /CME/

&&

.PRELIMINARY POINT TEMPS/POPS...
Jackson       77  94  70  97 /  20  10   0  20
Meridian      75  95  69  97 /  40   0   0  30
Vicksburg     77  94  70  97 /  30  10   0  10
Hattiesburg   77  97  74  97 /  20  20   0  40
Natchez       76  94  73  98 /  40  30  10  20
Greenville    77  92  69  97 /  20   0   0   0
Greenwood     75  93  68  97 /  20   0   0   0

&&

.JAN WATCHES/WARNINGS/ADVISORIES...
MS...Heat Advisory from 10 AM to 8 PM CDT Monday for MSZ047-048-
     053>055-059-061>065-072>074.

     Excessive Heat Warning from 10 AM to 8 PM CDT Monday for MSZ060.

LA...Heat Advisory from 10 AM to 8 PM CDT Monday for LAZ015-016-023-
     025.

     Excessive Heat Warning from 10 AM to 8 PM CDT Monday for LAZ024-
     026.

AR...None.
&&

$$

CME/SAS20/22