Scientific Forecaster Discussion
Area forecast discussion...update
National Weather Service Jackson MS
910 PM CDT Tuesday Jul 28 2015
Update...gradually weakening cluster of thunderstorms is currently
dropping south across western middle Tennessee and is prognosticated by a
few hires model runs to help instigate some showers and storms along
the Highway 82 corridor between gwo and Columbus before daybreak.
This is plausible...but late night into early morning probability of precipitation in this
neck of the Woods were only increased into the 20 to 30 percent
range because negative factors will fight against significant
convection making it that far south that quickly. Those negative
factors include general lack of lift associated with nearby upper
ridge center and 700-500mb thermal capping evident on 00z Jan radiosonde observation.
So we will be watching convection coming down from the north for the
rest of the night with expectations of the current slow weakening
trend continuing. Otherwise...anticipate dry conditions for the
night with very warm temperatures. The current heat
advisory/excessive heat warning layout for our region was kept
intact. Locations across eastern MS may be added to the advisory
overnight but at this point the question Marks of relatively early
convection tomorrow across eastern MS make it prudent to refrain
from making changes at this juncture. /Bb/
Aviation...VFR conditions will prevail through the taf period at
most terminals. Isolated rain showers and thunderstorms and rain possible late tonight into
early Wednesday at gwo/cbm/gtr may cause brief ceiling/visby
reductions...but the higher overall risks of impact from convection
for central and eastern portions of MS will come tomorrow afternoon.
Light generally west-SW winds expected through the period...but off
course gusty and erratic winds are possible around thunderstorms.
Previous discussion... /issued 313 PM CDT Tuesday Jul 28 2015/
Discussion...tonight through Monday night...upper ridging continues
to prevail across the arklamiss with another day of hot
temperatures. Heights will begin to decrease across the area
overnight and moisture will increase from the east. Precipitable waters will climb
above 2.0 inches across much of the area by Wednesday morning. The
upper ridge will continue to shift west on Wednesday and this will
allow a short wave to move from the north to south across the area
during the afternoon and evening hours. Expect showers and
thunderstorms to develop and with plenty of instability and moisture
expect some of these storms to be strong to severe. A limited area
of severe has already been introduced in the graphicasts and severe weather potential statement.
Heat will continue to be an issue on Wednesday and with the increase
in moisture along with the very high temperatures expect heat
indices to climb above 110 in the Delta...so a heat warning will be
issued for those areas. The heat advisory will be expanded further to
the east also.
With plenty of moisture across the area along with short wave energy
moving from north to south...showers and thunderstorms will continue
to be possible across the area Wednesday night into Thursday
A welcome surface boundary will begin to drop south across the area
on Thursday and this will bring another round of showers and
thunderstorms across the area. In the wake of the boundary slightly
cooler and much drier air will begin to spread south across the
northern portions of the area Thursday afternoon and build south
through Friday. This will be a welcome relief to the heat we have
been experiencing for quit some time. There could be some storms in
the southeast Friday afternoon...but it looks like much of the
remainder of the extended period will be dry. A nice weekend looks
on tap with temperatures still climbing into the low to middle
90s...but with much lower relative humidity and overnight lows
falling into the middle/upper 60s.
The dry conditions look to continue for the remainder of the
extended period...with an increase in temperatures and humidities as
upper ridging begins to strengthen and southerly moist flow returns
by Tuesday. /15/
Preliminary point temps/pops...
Jackson 76 97 77 95 / 12 31 32 40
Meridian 74 96 75 94 / 19 41 29 44
Vicksburg 76 98 76 96 / 9 20 28 32
Hattiesburg 75 98 76 94 / 14 38 38 51
Natchez 75 97 76 95 / 8 22 29 39
Greenville 77 99 77 94 / 10 16 23 21
Greenwood 76 97 76 94 / 17 25 25 25
MS...heat advisory until 7 PM CDT Wednesday for msz025>033-036-037-
Excessive heat warning until 7 PM CDT Wednesday for msz018-019-
La...heat advisory until 7 PM CDT Wednesday for laz016-023>026.
Excessive heat warning until 7 PM CDT Wednesday for laz007>009-
Arkansas...excessive heat warning until 7 PM CDT Wednesday for arz074-075.