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fxus64 kjan 221644 aab 
afdjan

Area forecast discussion...updated
National Weather Service Jackson MS
1144 am CDT Fri Sep 22 2017

Update...
updated for 18z aviation discussion

&&

Aviation...
18z taf discussion:
VFR conditions will prevail through the afternoon and evening,
although isolated showers and thunderstorms will develop in the
vicinity of mei and hbg which could briefly lead to lower flight
categories. After midnight, patchy fog development will lead to
MVFR visibilities from sunrise to mid morning Saturday./26/

&&

Discussion...
some isolated convection has managed to fire up this morning near
a 0-3km Theta-E bullseye over northeast MS. Would expect this to
diminish somewhat through the late morning diurnal convective min
period then begin breaking out again with the heat of the
afternoon. Made some adjustments to temps and sky cover as the
convection is obviously affecting these fields at present. /26/

Prior discussion below:

Today and tonight...

This afternoon Marks the first day of fall as the autumnal equinox
occurs at 302pm. However, it certainly won't feel like fall as
our Summer-like weather pattern will remain firmly entrenched over
the region. High pressure aloft will remain sprawled across the
eastern third of the country, as troughing occurs across the
western part of the Continental U.S.. temperatures today will once again be
above normal for September, with highs expected to reach the lower
90s. Afternoon and early evening isolated to widely scattered
showers and storms will be possible once again today. However,
coverage is expected to be on the low side as was the case
yesterday. Any activity that develops will diminish in the
evening, leading to another mild night with lows in the upper
60s/lower 70s. /28/

Saturday through Thursday...

The period will start out with a rather amplified synoptic regime
across the Continental U.S. As a Stout longwave trough digs over the western
states. This will help to amplify downstream ridging from the
Central Plains through the Midwest, but the arklamiss will remain
relatively spared from the higher heights and thus heat stress
issues thanks to an upper-level low retrograding beneath the ridge.
While temps will remain above average in the upper 80s to low 90s,
dewpoints mixing out into the upper 60s to low 70s will help to
preclude any heat stress issues. The upper-level low will meander
over the arklamiss through the weekend and into Monday before
getting picked up by the western Continental U.S. Trough that will be lifting
through the Midwest. Isolated to scattered diurnally driven
afternoon showers and storms will be possible each day through
Tuesday before drier air wedges in from the east. Shortwave ridging
will build in behind the departing upper-level low Tuesday and
Wednesday allowing high temps to climb back into the low 90s ahead
of an advancing cold front. Latest 00z global models disagree with
the timing of this front as the European model (ecmwf) remains faster with the front
pushing through the County Warning Area on Thursday while the GFS is slower with the
front coming through on Friday. The European model (ecmwf) also has a dry frontal
passage while the GFS remains more moist with an impressive
shortwave trough diving through the Great Plains. Went with a blend
of the two solutions for now with a slight lean towards the drier
and faster European model (ecmwf) given the spatial removal of the upper-level
forcing from the front. Regardless, this cold front will bring in a
much more seasonable fall airmass by next weekend. /Tw/

&&

Preliminary point temps/pops...
Jackson 90 70 90 69 / 19 12 17 16
Meridian 91 69 90 68 / 26 15 18 16
Vicksburg 91 70 90 68 / 16 10 18 16
Hattiesburg 91 69 88 68 / 26 16 17 16
Natchez 90 70 89 68 / 18 15 17 16
Greenville 93 70 91 70 / 15 4 19 16
Greenwood 90 70 91 69 / 20 6 18 16

&&

Jan watches/warnings/advisories...
MS...none.
La...none.
Arkansas...none.

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