Area Forecast Discussion
Issued by NWS Jackson, MS
FXUS64 KJAN 290229
Area Forecast Discussion
National Weather Service Jackson MS
929 PM CDT Tue Mar 28 2017
...SEVERE WEATHER EXPECTED WEDNESDAY NIGHT AND THURSDAY...
Updated for evening discussion.
A quiet night is in store across the CWA. Clouds will start to
increase from the south as the night progresses and some patchy
fog may start to reside down near Hattiesburg and along I-59 in
the early morning hours. The only changes that were made to the
latest forecast update was removing the POPs in the northern
region. A few showers were spotted over the Columbus area in the
last hour but they have cleared out. Overnight lows will still
remain in the lower 60s. /12/
Prior discussion below:
will continue over the next 24 hours as a shortwave upper ridge
axis moves across the region. This feature helped limit shower
activity through the day, which was driven almost exclusively by
low level moisture and diurnal instability. Late overnight into
tomorrow morning, we`ll see a resurgence of low stratus (and
perhaps some spots of fog in the southern portion of the area).
However, clouds should begin to break out late morning into the
afternoon. Southerly flow ahead of the next approaching storm
system and anomalous upper heights will make way for another warm
day on Wednesday. Rain chances are expected to be even more
limited than today due to a midlevel dry slot moving across the
Wednesday night through early next week...
An active period of weather will continue to exist through the
ongoing late March/early April time frame. Based on severe
weather climo, this falls in line with what usually our most
active period of the year.
The first threat of severe weather will exist late Wednesday night
and through the day on Thursday as a deep upper low crosses the
southern Plains and begins to approach our region. Mid-level
impulses translating around the closed low will serve as focuses
of storm initiation over the La-Tex region Wednesday evening,
pushing closer to our region on Wednesday night before moving into
the western portions of the ArkLaMiss soon after midnight. Models
have come into better agreement with the time of the progression
of this first wave, which led to the removal of PoPs before
midnight. SBCAPE values in excess of 1000 j/kg, 0-6km lapse rates
greater than 6 C/km, and 0-6 km bulk shear around 60kts suggest
all modes of severe weather will be possible.
A more complex, but still significant, threat of severe weather
will continue through the day on Thursday as the system progresses
through the region. Energy associated with the subtropical jet
will begin to increase along the base of the upper low before
beginning to split off as the upper low/polar jet begins to
slowly lift northward. This could lead to several different
solutions for our region. An MCS is expected to develop along and
near the Gulf Coast and could extend into the southern portions of
the ArkLaMiss. If this scenario plays out, it could disrupt low
level flow into the other portions of our region, while also
leaving a stabilized airmass in its wake. This could limit our
severe potential with the second round of storms that could form
along the surface front as it finally pushes through the region.
However, several models offer differing solutions, such as the
atmosphere over the region having time to recover after the MCS
progresses out of our region and ahead of the frontal passage.
This solution gives us the best chance to see two substantial
rounds of severe weather. Drier air will begin to filter into the
region behind the front and rain chances will decrease from west
to east Thursday night.
Upper level heights will begin to increase on Friday with a ridge
becoming centered over the region this weekend. This will result
in above average temperatures and dry conditions.
Storm chances will increase again early next week as a potent
upper level low crosses Texas. Ahead of this system, a strong low
level jet will pull a considerable amount of moisture and
instability into the region from the Gulf. Rain and storm chances
will begin to increase on Sunday night. PWats could increase to
above 2 inches as moisture continues to increase ahead of a
frontal passage. Early indications suggest a risk of flash
flooding and severe weather throughout most of the region. /jpm3/
00Z TAF discussion: Satellite imagery showed very few clouds
across the area at 00Z. VFR conds are expected to cont this evng
but models suggest MVFR to IFR cigs wl develop at most sites
after 08Z. Vsby restrictions may develop over the se again but
lower cigs are expected to be the prevailing flight restriction.
Conditions will steadily improve during the mid to late morning
hours Wednesday. VFR conds are expected areawide Wed aftn. /22/
.PRELIMINARY POINT TEMPS/POPS...
Jackson 63 86 65 79 / 10 4 20 73
Meridian 62 85 63 79 / 14 3 10 61
Vicksburg 63 85 66 79 / 11 5 57 74
Hattiesburg 64 84 65 79 / 5 4 11 63
Natchez 65 84 67 79 / 8 7 54 72
Greenville 64 82 65 76 / 17 4 79 71
Greenwood 64 84 65 76 / 16 3 56 75