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Area forecast discussion...updated 
National Weather Service Jackson MS
933 PM CDT Friday Aug 29 2014

Update...
cleared out the rain chances for the evening hours in the grids as
all convection has now dissipated. Precipitable water seems to be holding around 1.8
inches so far...according to 00z sounding. Expect that number to
climb to 2+ inches by the 12z sounding as the moisture plume moves
increasingly inland overnight. All models continue to show an area
of moisture/rainfall forming in Louisiana after midnight and moving
into arklamiss in the morning hours tomorrow. Will continue to
monitor this on radar and satellite overnight. Temperatures are currently
in the upper 70s/low 80s and probably won't be falling too much more
as clouds continue to move in and cover the area. /10/

&&

Aviation...
the early evening convection has ended with only patchy light rain
noted along the Highway 84 corridor at 01z Sat. VFR conds were being
observed at all taf sites at 01z and will continue through 06z. Deep
moisture increase from the south tonight will lead to additional
rainfall development after 06z that will spread north across the whole
area Saturday. MVFR ceilings and visibility restrictions will be common with the
rain Saturday morning. VFR conditions are expected by Saturday afternoon
but scattered thunderstorms will develop over the area. /22/

&&

Previous discussion... /issued 329 PM CDT Friday Aug 29 2014/

Short term...tonight through Sunday night...area radars show a
cluster of storms moving north through the Delta Region and another
swath moving up from the Gulf Coast. Conditions are a bit moister
out today than previous days. 12z kjan sounding indicated this with
precipitable water values around 1.8 inches...which is also depicted on blended tpw
satellite imagery with near 2 inches just south of the County Warning Area. The
region remains on the western side of an upper ridge and on the
eastern side of an approaching upper trough.

Models...including hi-res WRF models...continue to paint a rather
wet scenario for this upcoming Labor Day weekend. Moisture should
continue to increase over the region tonight and especially into
Saturday. Models show precipitable water values increasing to around 2.2 inches in
the east and 2.4 inches in the west by 12z Saturday. Theta-E values
of 335-345k also will move into the region as the upper trough
approaches from the west. Models continue to show some disturbances
moving through the moisture plume across the western portions of the
area. All of this spells widespread rain for Saturday across the
region...particularly in the west. Rain could begin as early as late
tonight after midnight and continue into the day tomorrow. In
addition...with such high precipitable water values...rainfall should be efficient
and if there is enough instability could produce heavy rain. Will
continue to mention the potential for heavy rain of 2-4 inches in
the west in the graphics and severe weather potential statement. There is the potential that if the
rain becomes more stratiform then quantitative precipitation forecast amounts may be lighter. As for
severe storms...still not thinking that this will be a big concern.
There could be a stray strong or severe storm but overall think the
biggest concern will be from the heavy rain.

Rain will continue into Sunday but should not be as widespread or
heavy. Highest chances right now are along and northwest of the
Natchez trace but enough moisture will linger to produce locally
heavier downpours. Rain should taper off Sunday night.

In terms of weather elements...I lowered highs on Saturday
especially in the west and northwest given expected thick cloud
cover and rainy conditions. This should leave temperatures into the
lower to middle 80s...possibly not even that high. I also continued the
trend of raising probability of precipitation for Saturday again especially in the west
where best moisture and lift should occur. Otherwise...I followed
mav guidance closely. /28/

Long term...Monday through Friday...models continue to show strong
agreement on the pattern evolution into next week as we transition
from a wetter pattern to one of drier conditions and more above
normal temperatures.

By Monday and into the remainder of the work week. The ridge off the
southeast Continental U.S. Will expand westward and take on a more flat appearance.
However...effects from this ridge will cause more subsident
conditions and limit precipitation chances for most of the week.
Overall...decent moisture will remain and this will be good enough to
support some low end chances (20-30%) each afternoon. What the area
will also see is a increase in temperatures. Look for high temperatures to range in
the middle 90s all week which will be some 4-6 degrees above normal to
start off Sep. Humidity will be on the high side during this time
(mon-wed) and look for heat indices to peak around 105 degrees. /Cme/

&&

Preliminary point temps/pops...
Jackson 74 87 73 93 / 50 90 37 32
Meridian 73 90 72 93 / 41 65 33 23
Vicksburg 73 86 73 92 / 61 91 39 35
Hattiesburg 74 91 74 94 / 32 64 26 25
Natchez 73 86 73 91 / 52 91 30 36
Greenville 72 84 73 90 / 58 91 56 38
Greenwood 73 85 73 92 / 49 91 51 39

&&

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

$$

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