Scientific Forecaster Discussion

Return to Local Conditions & Forecast

Without Abbreviations
With Abbreviations

fxus64 kjan 290310 
afdjan

Area forecast discussion
National Weather Service Jackson MS
1010 PM CDT Fri Apr 28 2017

..severe weather and flooding possible this weekend...

Update...
updated for evening discussion.

&&

Discussion...
overall going forecast looked pretty good but made a few changes
to the low temperatures, mainly in the east. Our area is situated
on the western periphery of the deep 590dm upper ridge over
western Atlantic and deep upper trough digging into The Rockies
into the southern-Central Plains tonight. Gusty winds due to
strong surface low (~1000mb) and increasing pressure gradient
that is expected to develop over the Southern Plains overnight
will definitely hold up low temperatures into the low-mid 70s in
the west while a slightly lighter gradient and some dewpoints in
the upper 60s may leave a window for areas along and north of I-20
(mainly near Meridian and up into the Golden triangle) could
reach down near lower 70s. Elsewhere expect a warm and humid night
overall with increasing clouds through the night. These low
temperatures could reach into the top 5 warmest low temperatures
for the date, especially if winds hold them up warmer overnight. /DC/

Prior discussion below:

Tonight through Saturday night...

A rather warm day by late April standards has been unfolding across
the arklamiss region today. Strong southerly winds have really
allowed for good mixing to occur across the area and temperatures
have reached the mid and upper 80s, with a few spots reaching the 90
degree mark. Southerly winds have been sustained around 20mph with
gusts to near 40mph at some spots. These winds should subside some
overnight but still gusty winds will be present through the
overnight hours. Very mild conditions will also occur with overnight
lows only dropping to the lower 70s(and even some mid 70s possible
in the west).

Another very warm day is expected tomorrow as strong southerly winds
will again allow for good mixing and temperatures will warm into the
upper 80s. It looks like there could be a better chance for spots to
see 90 degrees tomorrow as the region will be firmly entrenched in
the warm sector. Southerly winds will be sustained around 25-30mph
with gusts to near 45mph possible across the entire region. Thus, a
Wind Advisory has been issued for tomorrow across the entire area
due to the tightened pressure gradient. Our next weather system will
continue to take shape to our west across the Southern Plains
through the day tomorrow, with a warm front draped across the Ohio
Valley. As daytime heating occurs, some showers and storms may
affect the western portions of my forecast area from roughly mid-day
into the evening hours. As plenty of instability will be in place
and sufficient shear, there will be potential for a few severe
storms to affect mostly the western third of my forecast area. The
main concerns will be hail and wind but a tornado cannot be ruled
out given plenty of helicity in place. Hi-res guidance shows these
storms moving across locations west of I-55 before diminishing later
Saturday night. /28/

Sunday through Thursday night...

A very active extended period looks on tap for the area. On
Sunday morning a closed upper low will be centered over Oklahoma
and will move northeast through the day. A cold front extending
southeast into Louisiana and this boundary will sweep across the
state. Thunderstorms will be ongoing west of US early Sunday
morning and move into our Louisiana parishes by mid morning. This
line of thunderstorms will move across the area through the
afternoon into the early evening hours. Anomalous moisture will be
advecting north across the area with precipitable waters greater than 2 inches.
All modes of severe weather are anticipated across the area as
there will be good lapse rates, ml CAPES of 1500-2000 j/kg and
strong wind shear. Storm Prediction Center already has all of the area in a slight
risk for Sunday, and with the slower solutions of the models on
the most recent runs, expect that there is at least the
possibility of and upgraded risk in future outlooks. Along with
the possibility of severe, heavy rainfall will also be a concern.
With the abundant available moisture and moisture transport with a
340 Theta east axis over the area, expect widespread 2 to 3 inches
of rain with higher amounts possible.

The cold front will exit the area late Sunday night with a few
showers possible in the east overnight. High pressure will build
across the area on Monday and this will continue into Tuesday. Highs
on Monday will be in the mid/upper 70s warming into the 80s on
Tuesday. Another upper trough will deepen over the plains on
Wednesday as moisture once again increases over the area. A series
of short waves will move across the region beginning Wednesday and
this combined with the abundant moisture will bring the possibility
of multiple rounds of showers and thunderstorms beginning on
Wednesday and continuing through Thursday when the main upper
trough/cold front moves across the area. This has the potential to
bring more severe thunderstorms to the area, but the main concern
will be the additional heavy rainfall and flooding concerns. Please
stay tuned! Cool temperatures will prevail Thursday night as cool
high pressure builds in behind the front. /15/

&&

Aviation...
00z taf discussion:
while VFR ceilings will be prevalent early this evening, MVFR
ceilings will once again spread over the region from the south by
mid to late evening. No fog is expected as winds will stay breezy
through the night with sustained 10 to 20 knots and occasional
gusts of 20 to 30 knots. Ceilings will rise to VFR by 29/17z as
winds increase as well. Sustained southerly winds of 15 to 25
knots with gusts of 30 to 40 knots will be common during the
afternoon./26/

&&

Preliminary point temps/pops...
Jackson 71 89 72 79 / 9 14 13 95
Meridian 70 89 71 82 / 11 11 11 78
Vicksburg 72 88 72 76 / 7 20 32 98
Hattiesburg 72 87 71 81 / 12 17 15 81
Natchez 72 87 71 75 / 9 30 34 96
Greenville 73 89 73 75 / 10 23 41 96
Greenwood 72 90 72 79 / 7 16 17 96

&&

Jan watches/warnings/advisories...
MS...Wind Advisory from 9 am to 7 PM CDT Saturday for msz018-019-
025>066-072>074.

La...Wind Advisory from 9 am to 7 PM CDT Saturday for laz007>009-015-
016-023>026.

Arkansas...Wind Advisory from 9 am to 7 PM CDT Saturday for arz074-075.



&&

National Weather Service Glossary of Abbreviations