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Area forecast discussion...updated 
National Weather Service Jackson MS
1025 am CST Thursday Dec 25 2014

Discussion...quiet Christmas day on tap with lots of sunshine and
seasonal conditions expected. Most of the forecast is on track...but
did up temperatures a bit to fit with the situation of full sun and return
flow developing which has yielded a tad warmer temperatures than what some
blended guidance has shown lately. /Cme/


Aviation...VFR conditions will prevail this taf period. With the
return flow becoming more established late in the period...look for
an increase in low stratus around or after sunrise Friday. /SW/


Previous discussion... /issued 351 am CST Thursday Dec 25 2014/

Discussion...Christmas day through Friday night...merry Christmas
from the midnight shift here at National Weather Service Jackson! Look for a nice
Christmas day across the region as high pressure at the surface
builds through the lower Mississippi River valley. After a chilly
start this morning...highs will warm into the 50s under sunny skies.
Southerly flow over the area today will allow for slightly warmer
overnight lows... ranging from the middle 30s to around 40 under mostly
clear skies.

Conditions will continue to warm Friday and Friday night under
persistent lower and middle-level southerly flow. The combination of
an approaching middle/upper trough from the west and increasing warm
advection...with result in increasing clouds and rain chances from
late Friday afternoon through Friday night. Highs Friday will range
from the upper 50s to middle 60s. Lows Friday night will be on the
mild side as they only range from the middle 40s to upper 50s. /19/

Saturday through the onset of the period middle level
flow will have already been amplified by wave moving out of the Pacific
northwest into the southern rockies. Moist low level southerly flow will be
ongoing as surface high has shifted to the East Coast. Meanwhile...
deep SW flow aloft will have already tapped into the high precipitable water air
(values around 1.75) poised over the northwest Gulf of Mexico. All of this
acting as a prelude to isentropic rains breaking out over the area.

Retreating baroclinic zone ahead of surface cold front over Arkansas/la
Saturday looks to allow warm sector and middle 60 dewpoints to surge as
far north as the Highway 84 corridor Saturday afternoon into
Saturday night. While near moist adiabatic lapse rates are not that convective available potential energy of 300-500 j/kg are more than adequate for
thunder. GFS/European model (ecmwf) having difficulties forecasting 0-3km srh with
considerable differences between the two. However...they are in
agreement with deep layer shear values values of around 50 knots
over the warm sector. While there are positives and negatives for
organized convection...feel there is enough of a signal in the model
data to pose a limited threat over southern sections of the County Warning Area.

While surface cold front will have moved out of the area by Sunday
night...SW flow aloft will continue the anafrontal isentropic rain
regime until middle level short wave can pass Monday afternoon.
Meanwhile...strong wave will be digging south through the western US
and create a fast paced zonal flow over the southern Continental U.S.. as the
middle level system moves into The Four Corners by Wednesday/
Thursday...isentropic rains look to break out again over the
region. /26/


Preliminary point temps/pops...
Jackson 57 37 61 53 / 0 0 13 43
Meridian 56 33 60 48 / 0 0 13 35
Vicksburg 58 37 62 54 / 0 0 14 45
Hattiesburg 57 37 62 53 / 0 0 12 44
Natchez 58 42 63 57 / 0 0 24 61
Greenville 56 37 60 51 / 0 0 12 38
Greenwood 57 37 60 51 / 0 0 12 33


Jan watches/warnings/advisories...



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