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Area Forecast Discussion (AFD)

Issued by Jackson, Mississippi (JAN)

FXUS64 KJAN 161351

Area Forecast Discussion
National Weather Service Jackson MS
851 AM CDT Mon Sep 16 2019

Updated for morning discussion.



Hot and dry weather will persist today as ridging remains centered
just to our north. 850mb temperatures will be in the 18-20 C
range, which will support afternoon high temperatures in the mid
to upper 90s. Rain chances will remain confined to a tropical 
disturbance over the western Gulf of Mexico with much of the area
expected to stay dry. A stray afternoon thunderstorm will be
possible across far southern portions of the Pine Belt within a
belt of easterly flow between the aforementioned ridge and
tropical disturbance. The ongoing forecast remains on track and no
major changes were needed. /TW/

Prior discussion below: 

Today and tonight: early morning water vapor imagery/RAP analysis 
showed the circulation around a 592dam high centered over the 
Central Plains with a couple of features rounding this high that 
will affect our weather today. The first feature noted was a weak 
shortwave dropping over north Mississippi that will help draw drier 
air south into our CWA as it continues tracking east through tonight. 
The second feature was a mid/upper level low tracking west in the 
northwest Gulf of Mexico. This feature will aid convection south of 
our CWA that model consensus suggest may spread north to the Highway 
84 corridor this afternoon. Early morning surface analysis had an 
1020mb high centered over the Appalachians that will ridge back to 
the west across our CWA and maintain a dry east low level flow. 
Ridging surface and aloft will lead to another warmer than normal 
day and dry for all except our southern most zones where low chances 
of a few isolated storms will be carried this afternoon. Any storms 
that develop are expected to dissipate early this evening. 
Temperatures will top out in the mid to upper 90s which will lead to 
peak heat index values around 100F, especially in the west where the 
highest temperatures are expected. Mostly clear skies, light winds, 
and warmer than normal temperatures will be the rule again tonight. 

Tuesday into the Weekend...Hot and mainly dry conditions will 
continue through the rest of the work week as a steep and stagnant
upper ridge remains parked over the Mississippi River Valley. 
Highs on Tuesday through Thursday will remain well above their mid
September averages, approaching triple digits and record values 
each day at some locations. Although there is continuing 
confidence of temperatures in the upper 90s, the dry surface 
airmass and afternoon mixing will help to keep heat indices below 
the 105 degree threshold for any significant period of time. 

Pwats will remain between 1.25" and 1.75" with the highest values 
occuring in the southwest portions of the region. Consequently, the 
southwestern portions of the region will see the best chances of an 
isolated storm or two. Rain chances will begin to slightly increase 
as temperatures begin to slightly decrease as we get closer to the 
weekend and the upper ridge begins to slowly lose influence over our 
weather pattern. Global model solutions begin to drag a front close 
to the region late in the weekend/early next week but begin to fall 
beyond the scope of reasonable consensus during this period. 

On a climatic note, the coolest high temperature we've seen at KJAN 
over the first 15 days of September has been 93 degrees with an 
average high of 96 degrees. To put this in perspective, the average 
high on September 1st is 90 degrees. We haven't experienced a day 
with a high below 90 degrees since August 26th and none are 
forecasted for the 7 days. /JPM3/


12Z TAF discussion: 
MVFR vsbys were reported at GTR and PIB at 1030Z and MVFR conds wl
continue at GTR and PIB until 13Z. Elsewhere, VFR conditions wl
prevail through tonight. /22/


Jackson       96  71  98  72 /   4   0   2   2 
Meridian      96  68  98  70 /   3   0   1   2 
Vicksburg     98  70  99  72 /   5   1   3   3 
Hattiesburg   94  71  98  72 /  13   1   5   4 
Natchez       95  72  95  72 /  12   3   9   6 
Greenville    97  70  98  72 /   2   0   2   2 
Greenwood     96  70  98  71 /   1   0   2   3