Forecast Discussions mentioning any of
"ACARS" "MDCRS" "AIRCRAFT" "TAMDAR" "AMDAR" "WVSS" received at GSD on 12/12/23
Area Forecast Discussion...UPDATED
National Weather Service Jackson MS
905 PM CST Mon Dec 11 2023
...New MESOSCALE UPDATE...
.MESOSCALE UPDATE...
Issued at 904 PM CST Mon Dec 11 2023
Rest of Tonight...High pressure nearly direcly over the CWA will
result in another quiet night. Mostly clear skies and calm winds
will also allow for good radiational cooling, with lows ranging from
the middle 20s to lower 30s across the area. However toward day
break Tuesday, some high clouds will begin filtering into the region.
Overall, the ongoing forecast is in good shape. Other than some
subtle adjustments to hourly elements of the forecast based on
current trends, no major changes will be made on this evening`s
update. /19/
&&
.DISCUSSION...
Issued at 246 PM CST Mon Dec 11 2023
Latest afternoon obs show the core of a 1025mb surface high
pressure system is centered directly over the forecast area
today. As such, clear skies and deep mixing have yielded temps in
the mid to upper 50s and dew points mixing as low as 15-20
degrees. This is resulting in RH values in the 20-30% range, but
fuel and soil moisture levels are thankfully improved to limit
fire weather concerns in most locations following recent heavy
rain in the region. Min temps this morning were widespread mid to
upper 20s, and with high pressure still the main influence
tonight, temps overnight should range again from mid 20s to lower
30s. A few more high clouds may be in the region tomorrow, but the
daytime should be comparable to today`s seasonably warm and dry
conditions. /NF/
Tuesday Night Through The Weekend:
The influence of a departing upper trough and the remnant surface
high will continue to dominate the forecast through mid week.
Temperatures will generally be near or just below climate normals
with frosty mornings likely particularly in the typically cooler
spots. Afternoons will be pleasant with highs generally in the lower
60s F for most.
With upper ridging within the northern stream branch of the jet over
the eastern half of the country and into eastern Canada, a shortwave
over the west coast will attempt to move south underneath, becoming
largely cutoff from deep layer steering flow through mid week. It
will drift southeastward into the Southern Plains before jet stream
changes aloft into the weekend results in the steering flow becoming
more northwesterly. This will cause the trapped shortwave, at this
point likely a closed upper low, to be pushed more rapidly
southeastward and into the Gulf of Mexico. As glancing influence
from a potent, but distantly north, upper trough affects the
cyclone, some meager degree of aid in increased upper divergence in
addition to the primary lift generated by the closed low itself will
combine with increasingly tightened temperature
gradients/frontogenesis as aided by the warm gulf of Mexico to
result in surface cyclogenesis.
Locally, we will remain in the cool sector of the cyclone and could
see substantial rainfall in an increased deformation band and/or
near and north of any coastally enhanced warm/stationary frontal
zones. This is most likely across areas south of I-20 and in fact
could be mostly confined to areas near and south of the highway 84
corridor. Depending on the exact evolution of the system, some
corridor could face some risk of flash flooding. This event is still
just under a week out and involves a complex interaction of multiple
upper features as well as weak steering currents. For that reason,
forecast confidence is too low to introduce any formal hazards into
the forecast at this time. The risk will be monitored through
additional forecast cycles as we get closer to next weekend. In any
case, the risk for severe weather looks quite low over the next 7
days.
With increasing clouds and moisture heading into later this week,
overnight lows Thur/Fri likely only fall into the 40s F as opposed
to the 30s F we will see earlier this week. By Sunday night,
however, we likely begin to cool off again as the Gulf system moves
off and cold northerlies come in its wake. Lows will likely dip back
into the 30s F. /86/
&&
.AVIATION...
(00Z TAFS)
Issued at 528 PM CST Mon Dec 11 2023
VFR flight categories will prevail at all area TAF sites tonight
through Tuesday afternoon. Winds will be calm overnight, but will
become more east and east southeasterly late Tuesday morning into
the afternoon around 5 knots. With lows tonight ranging from the
middle 20s to lower 30s, some frost could develop on aircraft
surfaces. /19/
&&
.PRELIMINARY POINT TEMPS/POPS...
Jackson 31 62 35 61 / 0 0 0 0
Meridian 28 61 32 60 / 0 0 0 0
Vicksburg 30 63 34 61 / 0 0 0 0
Hattiesburg 30 62 35 62 / 0 0 0 0
Natchez 31 62 36 61 / 0 0 0 0
Greenville 31 60 34 59 / 0 0 0 0
Greenwood 31 61 35 61 / 0 0 0 0
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...None.
LA...None.
AR...None.
&&
$$
19