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Area forecast discussion 
National Weather Service Jackson MS
413 am CDT Monday Sep 22 2014

Short through Tuesday night...early morning water
vapor imagery/RUC analysis showed a shortwave dropping across the
middle Mississippi Valley toward northern Mississippi. Early morning
surface analysis had a cold front near Interstate 20 in our County Warning Area
with a 1024mb high centered over the Central Plains. The shortwave
trough will swing southeast across our region today and help drive
the cold front through our County Warning Area. Local radars showed a few showers
along and ahead of the cold front and mainly east of Interstate 55.
This activity will continue early this morning along an ahead of the
cold front that is expected to be south of Interstate 20 by sunrise
and push south of Highway 84 by middle morning. Cooler and much drier
air will filter into our County Warning Area today in the wake of cold front. Dew
points ahead of the cold front where mostly in the upper 60s and low
to middle 50 degree dew points were being observed behind the cold
front. Greenville reported a dew Point of 55f a 2am. The gusty north
winds will offset insolation and hold most of the area in the 80s.
Mostly clear skies tonight and a light north wind will contribute to
the coolest morning temperatures of the period Tuesday. Normal lows
run in the lower 60s. Lows Tuesday morning will be in the low to middle
50s at most locations and in the upper 50s over our southeast. Weak
middle level ridging will move back over our County Warning Area Tuesday and the
surface high will shift east across the Ohio vally resulting in a
dry northeast low level flow across our County Warning Area. The dry weather and
cooler than normal temperatures will continue through Tuesday night.
Normal afternoon highs run near 85f and most sites will top out in
the lower 80s Tuesday. Temperatures will bottom out several degrees
warmer Tuesday night than they will tonight but most sites will
still drop into the 50s Wednesday morning. /22/

Long term...Wednesday through next Monday...the main item of
interest in the extended portion of the forecast will be rain
potential this weekend and early next week.

The upper level pattern throughout the long term period will be
somewhat complex...leading to decreasing forecast confidence toward
the end of the week. Starting Wednesday...broad upper ridging will
encompass much of the Continental U.S....except for a shortwave trough over the
upper Midwest. As a sharp trough moves into the picture over the
Pacific coast...both the GFS and Euro depict an upper low cutting
off from the Midwest shortwave and retrograding southwestward toward
the Southern Plains at the end of the week. By the start of the new
week...the sharper Pacific trough is then expected to nudge the
cutoff low east/northeastward across the middle Mississippi Valley...all the while
a new cutoff low is expected to form over the western Continental U.S. From the
sharper West Coast trough. As I said...complex.

One thing that will help simplify the forecast for the middle to
latter half of the work week is the lack of moisture. Forecast precipitable waters
will remain near to below normal through Friday...keeping rain
chances well south of our area for the most part. Temperatures will
mainly be near normal during this time frame.

Things begin to change by the weekend. As the cutoff low/shortwave
trough moves closer to the will create a favorable upper
level environment for a surface low to develop near the baroclinic
zone across the northern Gulf. This would bring showers to the County Warning Area
during the Saturday through Monday time frame. To reiterate...
confidence is low in the exact timing and location of the highest
rain chances as these will be dependent on the eventual track of the
surface low. However...currently it is expected the best rain
chances will be for locations farther south and east in the forecast
area. /Dl/


Aviation...radar showed isolated showers and thunderstorms along a cold
front that was nearing I-20 at 09z. The thunderstorms may come in vcty of
mei and later hbg but showers are expected at hks and Jan. Brief
MVFR conds can be expected with the thunderstorms this morning but VFR
conditions are expected to prevail through Tuesday. The cold front
will be south of the area by 17z. Much drier air will move into the
area on gusty north winds late this morning into the afternoon.
Light NE winds are expected tonight. /22/


Preliminary point temps/pops...
Jackson 85 54 84 59 / 6 0 0 0
Meridian 86 50 83 57 / 6 0 0 0
Vicksburg 85 51 83 55 / 5 0 0 0
Hattiesburg 88 57 87 59 / 14 0 0 0
Natchez 86 54 81 59 / 13 0 0 0
Greenville 82 55 81 57 / 3 0 0 0
Greenwood 82 52 82 57 / 2 0 0 0


Jan watches/warnings/advisories...



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