Area Forecast Discussion
Issued by NWS Jackson, MS

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FXUS64 KJAN 220917
AFDJAN

Area Forecast Discussion
National Weather Service Jackson MS
417 AM CDT Sat Jul 22 2017

...SLIGHT HEAT RELIEF EXPECTED OVER THE NEXT SEVERAL DAYS...

.DISCUSSION...

Today and Tonight:

The upper ridge will continue weaken across the area today, and
this combined PWATS ranging from 1.8 to 2.0 inches and afternoon
heating, will allow for another round of thunderstorms. High
temperatures will be a little cooler across most of the area, with
highs in the low/mid 90s. Although the temperatures will be a
touch cooler than yesterday, dewpoints in the mid 70s will cause
heat indices to exceed 105 degrees for areas generally along and
north of I-20. A heat advisory is in affect for later this morning
through the afternoon hours.

The convection will diminish after sunset this evening with skies
becoming partly cloudy overnight. Expect warm overnight lows once
again in the mid 70s./15/

Sunday through the end of the coming work week:

Still looking like our region will get a bit of relief from the
hot and humid conditions through the first portion of the coming
week as the eastern extent of the heat ridge yields to a very weak
cut-off upper level disturbance over the Lower MS Valley vicinity.
It is important to emphasize that overall heat and humidity
levels will not be drastically lower over this period and the
main relief will come from a good deal of afternoon shower and
thunderstorm activity. On Sunday some northern and western
locations still may peak near 105 heat index values midday through
early afternoon, but at this point we do not anticipate needing
an advisory for tomorrow. The very slight cooling trend will
continue into Monday and Tuesday when peak heat index values
should remain closer to 100 degrees for most areas. Overall rain
chances Sunday through Tuesday will be highest over the eastern
half of zones although all locations should be fairly confident of
getting at least a bit of rain over this span. Certainly not out
of the question that some (luckier?) spots in eastern MS may get a
few inches of precipitation Sunday through Tuesday considering
thunderstorms will be producing locally torrential downpours. We
are relatively confident any flooding issues that arise should be
minor and extremely localized. There are no great signals for
particularly robust afternoon storms worthy of more than marginal
microburst threats.

Of course the re-wetting of the region through the early portion
of the coming week may have some negative impact by the time we
get to mid through late in the coming work week. By that time
model consensus is now pretty good that the very "dirty" eastern
extent of the heat ridge over us in the short term will
restrengthen over at least the northwest half of our region. This
evolution should gradually decrease rain chances and confine them
to mainly the southeast half of zones with peak afternoon
temperatures and heat index values responding upwards
(particularly over the Arklamiss Delta). So, once we get past
Tuesday it is quite possible will may be dealing with some
additional heat advisories being necessary, especially by Thursday
or Friday. This will be briefly mentioned in the HWO although
graphics will focus on short term heat implications for now.

Model consensus shows potential for a cold (more like "cool")
front sliding south into the region sometime next weekend. If this
boundary can come through with gusto our region has some hope of
getting more than marginal relief from the heat. However, at this
point it is too early to have much confidence in details this far
out in the forecast. /BB/

&&

.AVIATION...
06Z TAF discussion:
All sites are VFR, and expect these conditions to continue through
the morning hours. Another round of showers and thunderstorms
early this afternoon will bring tempo MVFR/IFR conditions, but
expect VFR conditions outside of any convection. The winds will
be light out of the south through the period.

&&

.PRELIMINARY POINT TEMPS/POPS...
Jackson       94  74  92  75 /  51  17  48  22
Meridian      94  74  92  74 /  53  21  44  23
Vicksburg     94  75  92  75 /  46  20  47  23
Hattiesburg   93  74  91  74 /  52  23  54  23
Natchez       92  74  90  74 /  50  22  59  24
Greenville    94  76  93  75 /  26  18  36  23
Greenwood     94  75  92  76 /  38  17  42  22

&&

.JAN WATCHES/WARNINGS/ADVISORIES...
MS...Heat Advisory from 11 AM this morning to 7 PM CDT this evening
     for MSZ018-019-025>042-046-047.

LA...Heat Advisory from 11 AM this morning to 7 PM CDT this evening
     for LAZ007>009-015-016-023-025.

AR...Heat Advisory from 11 AM this morning to 7 PM CDT this evening
     for ARZ074-075.


&&

$$

15/BB


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