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Area forecast discussion...updated 
National Weather Service Jackson MS
1003 am CDT Sat may 23 2015

Update...the only changes made to the current forecast was to
decrease cloud cover in most areas this morning. Otherwise...high
pressure centered northeast of our area will remain dominant today.
Isolated late afternoon and early evening showers and thunderstorms
will be possible in the southwest. /22/

&&

Aviation...VFR conditions will prevail across all taf site through
the period. Middle and high level clouds will be on the increase...but
should have no impact on flight categories. Some showers will be
possible in southwest MS but should not affect any taf sites. /26/28/

&&

Previous discussion... /issued 410 am CDT Sat may 23 2015/

Short term...today through Sunday night...cool temperatures abound
again this morning across the County Warning Area as surface high pressure over the
Tennessee Valley continues to control the dry airmass in place. The high
pressure center will move east today allowing our dry/pleasant air to
be replaced by moist/muggy air by late this afternoon. Southerly
winds and moisture increase should be sufficient by late afternoon
for some isolated storms over the far SW sections.

The low level moisture increase is only the beginning. Deep layered
S/SW flow will spread over the region tonight. Precipitable water/S will increase
from around 1 inch this morning to near 2 inches along and west of
the MS river by Sunday morning and spreading further east during the
day.

While a low level focusing mechanism will be absent...weak
shortwaves peppered in the middle/upper flow should easily allow
scattered to numerous showers and thunderstorms to develop by Sunday
afternoon when combined with daytime heating. While the airmass will
remain near tropical with weak lapse rates...the increased flow will
allow for deep layered shear values of 30-40 knots by Sunday
afternoon/evening over the western third of the County Warning Area. The models have
been consistent with this...thus will outlook a limited severe
weather threat for this area. Damaging winds will be the primary
threat as lapse rates remain too feeble for any decent hail
production. Also of concern is the increased low level shear.
Models...especially the NAM...are showing 25-35 knots of 0-1km shear
in this area. While wind profiles are mostly unidirectional with srh
values around 100...some turning during the evening may allow a
tornado or two to develop...especially with local/S less than 1kft./26/

Long term...Monday through Friday...an active long term seems to be
the general rule for this period. For the start of the work week we
will have an amplified pattern over the Continental U.S. With upper ridging to
the east and a broad upper trough to the west. We will be caught in
the periphery of both. The general pattern for the period was
generally agreed by the models and ensembles. There may be a window
of some strong to possibly severe storms for late Monday into Tuesday
along with the potential of some heavy rainfall. Models show that
upper jet energy will approach the region from the plains. This
energy will cross the region for late Monday into Tuesday as the
western US upper trough Narrows and pushes into the region by Tuesday
night. As for severe potential...models are showing good deep shear
of 30 to 40 knots at 0-6 km as well as 0-3km for late Monday into
Tuesday with 6-7c lapse rates. Model soundings shows srh around 200 along
with some interesting hodographs with the strong middle to upper level
flow. Primary risks damaging winds and some hail. There is also some
heavy rain potential with precipitable waters of around 1.7 to 2.0 inches with some
corfidi vector ridging of around 5 to 15 knots with strong moisture
transport. GFS was trying to paint some 4 plus inches from portions
of northeast Louisiana to western Mississippi. Will have to watch
this system to see how future model runs handle it. The cips
analogues also points to some severe weather potential across the
region for early in the week. Going for Wednesday into Saturday. The
upper trough axis will push over the region on Wednesday then push
east from the region. This will result in height rises from the west
as mean ridging rebuilds over the region. With precipitable waters from 1.5 to 1.6
expect more of a diurnal driven convection for mainly Thursday
through Saturday. /17/

&&

Preliminary point temps/pops...
Jackson 85 69 85 70 / 6 7 48 53
Meridian 86 66 86 69 / 5 5 43 49
Vicksburg 86 69 86 71 / 9 23 50 62
Hattiesburg 87 70 86 71 / 12 12 43 50
Natchez 85 70 85 70 / 23 21 55 61
Greenville 84 69 85 70 / 8 16 54 64
Greenwood 84 68 85 70 / 5 6 41 59

&&

Jan watches/warnings/advisories...
MS...none.
La...none.
Arkansas...none.
&&

$$

22/28/26/17

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