Scientific Forecaster Discussion
Area forecast discussion...updated
National Weather Service Jackson MS
947 am CDT Thursday Jul 24 2014
no update to the forecast grids needed this morning. The forecast
looks pretty good. Going to stick with the current thinking of
storms forming along and south of the boundary...which will be near
the I-20 corridor...this afternoon. 12z sounding showed a 2 inch precipitable water
this morning. Therefore...heavy rainfalls will be the main threat
today along with some strong wind gusts. /10/
a mix of low clouds/fog are bringing some lower visible and IFR/LIFR
conds to kgwo/kgtr/kglh/ktvr. Expect most of the conds to improve
after 15-16z at most taf sites with mainly VFR conds this afternoon.
Isolated MVFR conds possible between 18-22z at most taf sites due to thunderstorms and rain
direct impact. Winds will be gradually shifting to the northwest around 5-10
knots. Expect mix of fog/lower stratus and MVFR conds possible after 25/08z
at khbg/kmei...with some fog and lower visible/IFR conds possible between
25/08-12z at kgwo/kgtr. /DC/
Previous discussion... /issued 343 am CDT Thursday Jul 24 2014/
Discussion...today through Friday night...isolated showers have
been bubbling up off and on across the County Warning Area already this morning as
ample moisture remains over the region...along with a number of
outflow boundaries left behind from yesterday afternoon/evening's
convection. Factor into the equation daytime heating...an upper
trough digging into the deep south...and a weak front dropping south
into and through the region...and the stage should be set for showers
and storms to continue to develop over the arklamiss through a good
portion of the day...until the front passes. Although the most
intense convection will be capable of producing some gusty winds
around 30-35 miles per hour...heavy downpours will be likely with all activity
That said...guidance overall was a bit stingy with probability of precipitation for today.
However...for the reasons stated above...increasing probability of precipitation areawide
for today simply made more sense than keeping rain chances confined
to the south as suggested by the GFS. After some adjustments...probability of precipitation
for today now resemble those of the European model (ecmwf) than those of the GFS and
As the front continues to push south through the evening and into
tonight...convection will follow suit and should gradually taper off
as daytime heating wanes. While some isolated activity could linger
overnight...it'll likely remain confined to the Highway 84 corridor
in the vicinity of the now slowing front. Some patchy fog will also
be possible in my far southern zones early Friday morning as well...
particularly over southeast Mississippi. Behind the front...
slightly drier air will advect south and into the remainder of the
County Warning Area overnight.
Middle-level ridging will increase across the arklamiss from the west
on Friday. With some slightly drier air now over the region...
temperatures Friday afternoon will be a little warmer compared to
previous afternoons. With mostly sunny skies expected...highs
Friday will warm into the low and middle 90s...with some small
rain chances over mainly south central and southeast Mississippi
near the stalled front Friday afternoon. Lows Friday night under
mostly clear skies will fall down around 70. /19/
Saturday through next Thursday...middle level ridging will build into
the region for Saturday and Sunday. This will allow highs both days
to climb into the middle 90s with heat indices in the 100 to 105 range.
Expect both days to be mainly dry with only very isolated storms.
A middle level trough will amplify over the Great Lakes region by Monday
which will force the ridge back to the west and allow a surface cold
front to push across the forecast area. This will lead to a chance
of thunderstorms Monday and Monday night. The front will hang up
along the Gulf Coast Tuesday providing a chance for some showers in
the southern forecast area.
The middle level trough will remain amplified through middle week with all
models showing a wave moving across the region in the
Wednesday-Thursday timeframe. Thus...will carry chance probability of precipitation through
the latter part of the forecast.
High tempertures will be near seasonable norms Monday and Tuesday
and then trend below normal by middle week. /SW/
Preliminary point temps/pops...
Jackson 92 68 93 71 / 24 13 9 6
Meridian 91 68 93 70 / 27 13 13 6
Vicksburg 91 64 93 68 / 20 12 6 6
Hattiesburg 92 71 94 73 / 34 19 27 7
Natchez 91 70 92 72 / 26 19 14 5
Greenville 91 65 92 70 / 15 4 3 6
Greenwood 91 63 92 67 / 16 5 3 6