Scientific Forecaster Discussion

Return to Local Conditions & Forecast

Without Abbreviations
With Abbreviations

Area forecast discussion 
National Weather Service Jackson MS
442 am CDT Sat may 30 2015

Discussion...

Through Sunday night...

It still looks as if a slow moving trough set to progress through
the lower MS valley this weekend will make for intermittently stormy
conditions in most locations...possibly even at night. A lobe of
energy rotating through the broad trough axis is instigating a fair
amount of showers and storms just to our northwest as I write. Some
of this activity will likely build southeast into the arklamiss Delta
through the morning while other areas remain largely dry until at
least midday. Locations in eastern and southeastern MS should remain
void of much thunderstorm activity the longest...allowing them to
heat up close to 90 degrees and build associated instability. It is
in these areas southeast of the Natchez trace where stronger storms
with gusty winds and small hail are more likely this afternoon. But
even with this expectation...wind shear and instability ingredients
should remain insufficient for more than a few isolated low-end
severe storms while tame dcape and lapse rates are not very conducive
for microbursts either.

Going into tonight a good deal of thunderstorms should diminish in
the evening initially...but model consensus suggests convergence
near an incoming weak surface front will probably trigger scattered
showers and storms along and northwest of the Natchez trace later in
the evening and into the overnight. Some heavy downpours could
result from this overnight activity although severe potential looks
quite meager.

Into Sunday the slowly progressive nature of the trough should tend
to focus the bulk of showers and thunderstorms southeast of the
arklamiss Delta (especially in the afternoon). Potential for
significant destabilization even in southeast MS looks more limited
than today considering more widespread nature of cloud cover and
morning to midday showers and storms. Once again a severe storm or
two cannot be ruled out at this point considering there will be a
bit of atmospheric shear but there is not enough going for the setup
to include mention in the severe weather potential statement. Sunday night showers and storms may
tend to get sequestered into southeast sections of the region
quickly in the evening with potential for lingering overnight
activity lower than will be the case late tonight.

It was mentioned above that the severe weather potential statement will be kept clear of severe
thunderstorm threats...but heavy rain threats were also considered
for inclusion and deemed lacking as well. It is quite plausible
through the weekend a few isolated spots could pick up 2 to 3 inches
of rainfall but it will likely not come in a very short span of
time. This expectation...in consideration with the fact of the
ground not being overly saturated in most areas...makes ME think
flooding problems will be generally avoided. /Bb/

Monday through Friday...the long range forecast continues to be in
flux as model guidance trends toward a more progressive solution
resulting in a drier and warmer stretch of weather...a big change
from the recent consensus for a meandering cut-off low that was
expected to bring rainy weather to the arklamiss region.

To start the work week...an open wave will continue to slowly push
southeast across the lower MS vally region with moisture convergence
setting up ahead of the trough axis over eastern/southern MS Monday afternoon.
Although shear is expected to be weak...there could be substantial
instability supportive of strong to perhaps severe storms during peak
heating. Thereafter...the threat for heavy rainfall and severe
weather will drop off significantly for middle week. The gefs does have
several members cutting off shortwave energy in the vicinity of the
central Gulf Coast...but its mean low position is considerably
farther east suggesting that associated warm advection and large
scale forcing/precipitation will focus east of the forecast area. So have
continued the trend of reducing probability of precipitation and confining them more to
southeast of the Natchez trace.

By the end of the week...there are some indications that easterly
flow north of a closed low in the vicinity of southern Georgia/Florida will help
to advect deeper moisture far enough west to increase probability of precipitation over
central/eastern MS. Otherwise...it is Worth noting that we have increased
high temperatures a little for next week based on latest trends. /Ec/

&&

Aviation...mainly MVFR flight cats will be possible through the
morning hours due to low ceilings. The highest potential for sub-
MVFR flight cats through 9 or 10 am will be at hbg/pib/mei/nmm where
very low stratus and or fog will be possible. Otherwise anticipate
south to southwest winds of 8 to 16 miles per hour today although gustier winds
and temporary IFR conditions will of course be possible midday
through afternoon in all areas due to scattered to numerous
thunderstorms developing. /Bb/

&&

Preliminary point temps/pops...
Jackson 84 67 83 65 / 70 49 66 39
Meridian 86 66 85 65 / 57 40 64 46
Vicksburg 85 68 83 65 / 71 56 56 32
Hattiesburg 88 67 86 67 / 50 40 60 44
Natchez 85 68 82 66 / 67 53 59 37
Greenville 84 68 81 64 / 61 51 42 22
Greenwood 83 67 82 64 / 66 55 48 27

&&

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

&&

$$

Bb/ec

National Weather Service Glossary of Abbreviations