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fxus64 kjan 212326 

Area forecast discussion
National Weather Service Jackson MS
626 PM CDT Wed Mar 21 2018

updated for 00z aviation discussion


00z taf discussion:
VFR conditions will prevail through Thursday. Gusty northwest
surface winds will diminish quickly with sunset early this
evening, and light winds are expected thereafter. Otherwise, the
only concern may be frost that could develop on aircraft during
the predawn hours at gtr/mei. /Ec/



Tonight and tomorrow:

Overall expect a quiet night tonight as the surface ridge axis moves
through the region. As the trough and cold front move off the
Atlantic Seaboard, expect strong mid-level and surface ridging to
build towards the region. Expect pws around or less than half an
inch to a quarter of an inch to build in. With the surface ridge
axis moving directly over the mid-Mississippi Valley and arklamiss,
winds will gradually weaken into the overnight hours. With light
winds & clear skies, expect efficient radiational cooling to occur.
We could reach just near freezing in cold spots up Highway 25 or
into the Golden Triangle, but right now it looks as though we will
remain above freezing. Due to areas to widespread frost potential in
the Golden Triangle and cold spots of Highway 25 possibly falling
near freezing, continued the elevated risk for frost/freeze while a
limited risk for frost/freeze along and east from Grenada to Canton
to Heidelberg area. This could continue bring risk to harm any
sensitive unprotected vegetation, so continue to take preparations.

As the mid-level ridging and surface ridge axis builds into the area
Thursday , expect thermal profiles to warm as dry air lingers
around. This will help temperatures warm closer to normals in the
mid-upper 60s to low 70s in the south & southwest. Even with better
mixing tomorrow due to dry air and warmer temperatures, winds will
be light and limit fire danger potential. Due to that, kept severe weather potential statement
clear on Thursday. /DC/

Thursday night through wednesday:

The period will start off with continued dry northwesterly flow
aloft as the region remains between longwave troughing centered
over the mid-Atlantic and ridging building in across the Great
Plains. The Great Plains ridge is progged to deamplify and
flatten by Friday evening as it progresses eastward into the Ohio
River valley. There's good model agreement that a weak shortwave
trough will quickly eject out of the Desert Southwest Friday
morning and follow quickly behind the dampening ridge and will be
located over the Midwest by Saturday morning. This shortwave and
associated surface low will help drag a cold front towards the
area on Saturday into Sunday. At the same time, a Stout sub-
tropical ridge is expected to propagate from central Mexico and
become centered over the southern Gulf of Mexico. The front will
make slow southerly progression through the arklamiss Saturday
night into Sunday with flow becoming zonal and increasingly
oriented parallel to the frontal boundary. Widespread precip is
not expected with the front and there is uncertainty as to how far
south it will make it before stalling and eventually moving back
north. Nonetheless, a few showers and storms will be possible
mainly along and north of the I-20 corridor Saturday and Sunday.
Any storms that are able to form on Sunday afternoon could be
strong to possibly severe with upwards of 1500 j/kg of SBCAPE,
steep mid-level lapse rates of 7-7.5 c/km, and 40kts of deep layer
shear, however confidence in any storm development remains low
due to a lack of forcing.

By Monday, the sub-tropical ridge will become centered over
Florida with mid-level winds quickly becoming southwesterly
across the region. A backdoor cold front is also expected to move
through from the east Monday night into Tuesday morning. Some
showers can be expected across the area with this front, but once
again widespread precip is not expected. Attention then turns to
the main storm system that will impact the area mid to late next
week. A highly amplified pattern will begin to take shape Tuesday
evening into Wednesday as an impressive trough digs across the
southwestern Continental U.S. And the sub-tropical ridge axis builds across
the mid-south. This will setup a prolonged period of moist
southwesterly flow across the arklatex that will eventually shift
into the County Warning Area. While uncertainties remain and this event will take
place mostly outside of the forecast period, its Worth noting
that a heavy rainfall and flash flooding threat could develop
across the arklamiss by late next week. /Tw/


Preliminary point temps/pops...
Jackson 38 69 44 76 / 0 0 0 0
Meridian 35 66 41 74 / 0 0 0 0
Vicksburg 39 71 45 77 / 0 0 0 0
Hattiesburg 37 69 41 76 / 0 0 0 1
Natchez 40 71 46 77 / 0 0 0 0
Greenville 39 66 46 75 / 0 0 0 0
Greenwood 37 66 46 74 / 0 0 0 0


Jan watches/warnings/advisories...

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