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fxus64 kjan 231250 

Area forecast discussion
National Weather Service Jackson MS
750 am CDT Sat Jun 23 2018

updated for 12z aviation discussion


12z taf discussion:
a mix of VFR, MVFR and IFR ceilings are occurring across the area
this morning. Expect that these ceilings will rise through the
morning, with Highway 82 taf sites taking a little longer to see a
return to VFR conditions. Additional showers and storms are
expected this afternoon, which could bring a brief reduction in
flight categories to any site that encounters a thunderstorm. /28/


through tonight: a front is stalled this early morning roughly
from the arklatex through the mid south. As of 9z, areas of low
stratus were beginning to develop and spread northward across our
area. Meanwhile, an mesoscale convective system is tracking eastward across parts of
western Arkansas. As the mesoscale convective system continues eastward, the consensus among cam
guidance is for most of it to pass north of the County Warning Area and weaken
somewhat through the morning hours. However, the southern part of
the complex could clip areas mainly north of Highway 82 as it
weakens through the mid-morning hours. Redevelopment along
residual boundaries across northern zones will then be possible
later in the day with the diurnal uptick in instability..
effective deep layer shear of up to 30 kt is expected to remain in
this part of the forecast area, with relatively steep mid-level
lapse rates, suggesting severe storms will be possible with any
convection that does occur in that area.

Across the rest of the forecast area, rain chances will be much
lower as a surface ridge begins to build in from the south and
deep layer moisture decreases. It will be rather warm today, with
highs in the low to mid 90s (except perhaps a few areas in north
MS, where clouds/rain may disrupt heating more). Guidance has
trended toward more mixing out of low level moisture during the
day today, but forecast dewpoints still suggest heat indices
approaching 105 over a portion of the area - mainly NE la and
parts of the Delta. Still, we'll continue to highlight increasing
heat stress concerns in the severe weather potential statement as heat ramps up into next week.
Dry and seasonable conditions are expected tonight as the high
continues to build in. /Dl/

Sunday through friday: the heat returns next week, with heat
indices near 105 nearly every afternoon for most of the County Warning Area. Right
conditions on Tuesday may be the most oppressive so far with
values slightly above 105. Will maintain the current wording in
severe weather potential statement for heat. Models were good agreement for much of the week,
rain chance varied slightly. Highs will be in the mid to upper 90s
for much of the week and overnight lows will be in the mid to
upper 70s, so there will be little relief from the heat next week.

A couple boundaries old and new may bring some afternoon rain
chances, mainly for the eastern zones a several days next week. The
area should be generally dry Sunday and Monday. The hi-res models
show some convection Sunday afternoon, model soundings for Jan show
some instability and a cap, but lapse rates were marginal. Any
storms that develop may be Worth watching. As a low pressure systems
and cold front push through the Midwest Tuesday, a stationary
front(boundary from today stalls over the mid south) dips into the
eastern zones bringing a few showers and thunderstorms. The ridges
moves further east allowing a front to sweep across. The tail end of
the boundary seems fairly week by the time it makes here late
Wednesday/Thursday, but there will be plenty of warm moist air
around to support convection. By the weekend the ridge will be
further south and east, with waves of tropical air flowing into the
region. Look for scattered showers and thunderstorms from mid week
on, with rain chances likely or better by the weekend. /7/


Preliminary point temps/pops...
Jackson 92 74 93 74 / 2 1 7 4
Meridian 95 74 93 73 / 5 0 7 6
Vicksburg 91 74 93 73 / 1 5 10 2
Hattiesburg 93 74 95 74 / 2 4 14 7
Natchez 91 74 92 74 / 1 8 10 3
Greenville 90 75 92 75 / 29 5 5 4
Greenwood 91 74 92 73 / 23 5 7 4


Jan watches/warnings/advisories...


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