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fxus64 kjan 260530 

Area forecast discussion
National Weather Service Jackson MS
1130 PM CST Sat Feb 25 2017

updated for 06z aviation discussion


06z taf discussion:
VFR conditions will prevail through the 24hr taf period. Light north
winds tonight will become S/southeast during the day tomorrow. High
clouds will begin to move into the region late in the period.


a sfc ridge and associated Continental polar airmass is centered
over the lower Mississippi River valley with current temps already
in the low to mid 40s. A relaxed sfc pressure gradient under
clear skies will allow for efficient radiational cooling tonight
with temps dropping into the low to mid 30s area wide and even
some upper 20s in the northeast portion of the County Warning Area. Tweaked
overnight min temps a degree or two, but overall the forecast is
on track and no major changes were needed. /Tw/

Prior discussion below:

Through the day sunday:

Modified Arctic air is streaming down into the region this
afternoon. Temperatures range from 5 to 10 degree below average
in northwestern zones to the pleasant (and near-average) mid 60s
in southeastern zones. Given the recent warmth i'm sure even temp
Marks close to normal feel a bit chilly, especially given the
breeze. Expecting winds to die down tonight with skies remaining
clear and the atmosphere very dry. This should be rather optimal
for radiational cooling and locations roughly along and northeast
of the Highway 49 corridor are expected to get down to (or a
little below) freezing. Usually in late February such readings are
nothing to mention twice, but given the warmth of this winter and
the early blooming, some people might be prompted to protect some
tender vegetation.

Tomorrow winds will turn around to the southeast and south as the
day progresses, although winds will not be quite as gusty as
today. Despite the southerly vectors we do not expect moisture to
increase with any rapidity and only some mid to high layer clouds
will be streaming in from the west by the afternoon. The start of
the day will of course be chilly, but by afternoon highs should
mainly be ranging from the mid 60s to near 70 (once again, above
average). /Bb/

Sunday night through next week...

We will be looking at an active period with rain chances coming for
Sunday night through Wednesday night with mild temperatures.
This will be followed by dry and cool weather for Thursday and
Friday. The best severe potential looks to be on Wednesday with the
cold front passage. There will be some limited severe potential
for Monday and Tuesday.

On Sunday surface high pressure will be well east of the region as
we get return southerly flow. Pwats will gradually increase to
around 1.2 inches on Sunday night from the west. A weak disturbance
coming from the Southern Plains will bring in showers for Sunday
night. Showalters of -1 and lapse rates of 6-7c will bring in some
elevated thunder potential for Sunday night. On Monday another
disturbance will cross the region. Instability will be on the
increase as with lapse rates around 7-7.5c, MUCAPE 1800-2000
j/kg, Vermont from 28-30,and showalters -2 to -4 with 60s dewpoints. A
warm front will be making its way north across the region on
Monday into Monday night. This will increase thunderstorm
potential esp in the warm sector. The upper jet will increase
during the day toward the north. A few of the storms may become
severe, especially on Monday afternoon, but rising height fields
and weakening low low level jet will limit the severe storms from
becoming too robust. Models show that convection will linger
across the north on Monday night with the location of the upper

On Tuesday a midlevel trough will be pushing toward the plains. This
will push a cold front toward the Ozarks for Tuesday night. Surface
based instability will be prevalent with lapse rates 6-7c, marginal
shear, showalters -2 to -4,VT 28-30, and MUCAPES around 1800 j/kg.
Storm Prediction Center has a 15 percent graphic pushing toward our northwest Delta
for late Tuesday. With this in mind will put a limited severe
graphic for the northwest Delta Region with the approaching system
for late Tuesday into Tuesday night. The primary risks will be
damaging winds and hail.

On Wednesday the midlevel trough will be pushing toward the region
from the plains. This will send a cold front into the region. So
with an increase in deep layer shear, good instability and lapse
rates will continue the limited region wide potential for severe
weather in the severe weather potential statement for Wednesday. The primary risk will be hail,
and damaging winds. The rains will end from the west on Wednesday
night in the wake of the cold front. The models have some timing
issues with the passage of the front for Wednesday into Wednesday
night. Cool high pressure will build in from the plain on Thursday
into Friday.

As far as temperatures are concern we will be looking at a warming
trend as we enter the work week with highs reaching the upper 70s to
around 80 on Tuesday. Lows will rise to the 60s by Tuesday night.
In the wake of the cold front on Wednesday highs will be in the 60s
for Thursday and Friday. Lows will dip into the 30s and 40s for
Thursday night and Friday night. Some locations in the northeast may
dip toward freezing on Friday night.

Looking into next weekend it looks like our rain chances will come
back to the region on Sunday with a shortwave trough coming from the


Preliminary point temps/pops...
Jackson 31 67 52 74 / 0 1 38 64
Meridian 30 67 47 70 / 0 1 18 61
Vicksburg 31 68 54 75 / 0 1 49 63
Hattiesburg 33 69 51 76 / 0 1 12 55
Natchez 35 68 57 75 / 0 1 37 62
Greenville 31 63 50 69 / 0 2 64 68
Greenwood 29 65 50 68 / 0 1 53 69


Jan watches/warnings/advisories...


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