Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Jackson MS
333 am CDT sun Jul 31 2016
Short term...today through Monday night...local radars are
indicating the MCS, that moved into the area during the late evening,
has just about devolved into a remnant mesoscale convective vortex over central portions of
MS this morning. Those that saw the rain have cooled into the lower
70s, while elsewhere mid to upper 70s were common.
The mid/upper level ridge that has been persistent over the southern
Continental U.S. Will begin building over the northern Gulf of Mexico this
morning and drifting to the northwest tonight into Monday morning.
Despite the proximity of the ridge and feeble lapse rates, scattered
showers and thunderstorms still look like a good bet this afternoon
as the airmass remains very moist (pws ~ 2 inches). Northern areas
should have the best chances for convection this afternoon as those
areas remain exposed to the westerlies and have slightly better lapse
rates that far away from the ridge.
By Monday, the high center will have settled over the arklatex
region putting the County Warning Area on the eastern periphery and into more of a
mid level northerly flow regime. Pws remain around 2 inches and with
weak shortwaves embedded in the flow, expect scattered afternoon
convection to once again dot the landscape.
With the moist airmass and warming daytime temperatures, heat
indices in the lower 100s should be common today and near 105 by
Monday. The one respite that we will have both today and Monday will
be the afternoon convection. This may keep the high heat indices
Long term...Tuesday through Saturday...the presence of ridging
aloft will subtly increase across the region throughout the course
of the long term period. At the surface, high pressure will remain
wedged into the forecast area front the east. This will result in
weak southerly flow and a continued humid airmass over the County Warning Area.
Each afternoon, highs will warm into the middle 90s. This, combined
with dew points in the low and middle 70s, will yield afternoon heat
indices in the 100-107 range through a good portion of the period.
This looks to especially be the case across the Delta, where the
issuance of a heat advisory could be needed before all is said and
done. Lows each night will fall into the middle 70s.
Isolated to scattered showers and thunderstorms will be possible
each afternoon. This convection will quickly dissipate around
sunset each evening as daytime heating gradually wanes. /19/
Aviation...MVFR visibilities in fog will give way to VFR conditions
by 31/14z. Scattered rain showers/thunderstorms and rain developing after 31/18z will mostly
affect the vicinity of most taf locations. However, those taf sites
that are impacted by thunderstorms and rain will see brief lowerings of flight
conditions to IFR. The convective potential will remain until
Preliminary point temps/pops...
Jackson 93 74 93 75 / 28 28 43 24
Meridian 96 75 96 75 / 26 23 51 35
Vicksburg 93 75 94 76 / 28 25 34 23
Hattiesburg 93 75 93 75 / 28 29 42 24
Natchez 93 74 93 74 / 47 22 41 28
Greenville 93 75 94 75 / 44 20 26 16
Greenwood 92 74 93 74 / 39 29 34 17