Scientific Forecaster Discussion

Return to Local Conditions & Forecast

Without Abbreviations
With Abbreviations

Area forecast discussion...updated 
National Weather Service Jackson MS
828 PM CDT Tuesday Jul 22 2014

Update...with the upper low now along our southern border...
convection is hanging on well into this evening. Forecast probability of precipitation were
increased for the evening hours...with a substantial decrease in
activity expected by the 4z-5z time frame. Also updated hourly
temperatures/dewpoints to account for current trends with rain-cooled air
over much of southeast Mississippi. Updated products are currently being
sent. /Dl/


Aviation...convection is decreasing across the area this evening.
Both ceilings and visibilities could briefly be reduced to MVFR/IFR
status if showers is observed within each sites respected taf sites.
Otherwise...VFR conditions will prevail into the evening as
convection diminishes. Thereafter...MVFR ceilings in the east and
MVFR visibilities everywhere will be the rule until around 14z
Wednesday morning. Some thunderstorms in the vicinity will be possible by afternoon mainly
along the eastern taf sites./17/


Discussion...tonight through Wednesday night...showers and storms
associated with a retrograding low pressure system have broken out
across the forecast area as expected this afternoon. This activity
will continue through the remainder of the afternoon and will be
capable of producing some heavy downpours...along with some gusty
winds...and perhaps some hail...particularly across my southeast and
south central zones. As daytime heating wanes through the evening
hours into tonight...much of this convection will eventually
dissipate. Low temperatures tonight will fall to around 70 with some
cloud cover associated with the westward drifting low expected to
remain overhead through the night.

Once again...scattered showers and storms are expected from late
morning through the afternoon on Wednesday as daytime heating in
this moist air mass destabilizes our atmosphere...with the aid of
the the upper low still residing over the arklamiss region...
although a bit further west than on Tuesday. Just as we observed on
Tuesday... some locally heavy downpours...gusty winds...and small
hail will again be possible with the most intense convection
tomorrow afternoon. That said...storms are expected to remain below
severe limits. Given the cloud cover over the region associated with
the addition to convection meandering about...I did adjust
highs down a couple of degrees in most locations as they again peak
around the 90 degree mark.

Most convection will dissipate over the County Warning Area Wednesday evening as
daytime heating wanes. the upper low weakens and an
upper trough digs south into the southeast United States...a front
is forecast to also drop south into the middle-south region late
Wednesday night. This front...or any outflow associated with
convection that's ongoing near it...could spark some showers or
storms that may impede upon my north central and northeast zones
toward day break Thursday morning. Otherwise... lows will again
fall into the lower 70s. /19/

Thursday through next big pattern change for the
region. With the large area of high pressure planted over The
Rockies...the arklamiss will continue to get fronts and weak
disturbances every few days. This in addition to continued ample soil
moisture content...temperatures are likely to be at or just below
normal through the extended. Stuck with guidance generally for probability of precipitation.

By looks like the latest stalled front will be
replaced with an approaching cold front. This boundary is likely to
stall along the coast over the weekend...before the next front moves
into the region around Monday. Each system seems to be lacking much
upper level support and the main surface low with each system is
also distant. However...the models are bringing in plenty of very
moist and unstable air from the Gulf. There is a chance of rain
across the area nearly every day. With the best dynamics associated
with the systems staying to the north and the western ridge wavering
further east some days...much of the thunderstorm activity will miss
the western zones...basically areas east of Interstate 55 through
the period. Of course there could be some isolated to scattered
thunderstorms...but probability of precipitation right now are low. Between each front will
be a day or two of mostly clear skies and mild conditions. Not
anticipating a pattern shift this forecast period. /07/


Jan watches/warnings/advisories...



National Weather Service Glossary of Abbreviations