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Area forecast discussion
National Weather Service Jackson Kentucky
148 am EDT Wed Sep 18 2019

issued at 148 am EDT Wednesday Sep 18 2019

Updated the grids to input the latest observations and trend
through the overnight hours. Left the fog forecast as is with the
main impact being in the river valleys.

Update issued at 1050 PM EDT Tuesday Sep 17 2019

Just a quick update to touch up the sky grids through the rest of
the night adding more high ones to the west and taking them down
in the east. Did also add in the latest obs and trends for the
T/TD grids - otherwise all were on track. These minor updates
have been sent to the ndfd and web servers.

Update issued at 740 PM EDT Tuesday Sep 17 2019

23z sfc analysis shows high pressure to the north of the area
providing a bit drier and cooler air mass for eastern Kentucky
this evening. Some cu does remain in the far southeast parts of
the cwa, but even these will fade out and dissipate by late
evening leaving mostly clear skies behind. Currently readings are
in the upper 70s to lower 80s most places with dewpoints in the
lower to middle 60s. Wind have been mainly light from the north
and will settle to calm toward midnight. Have updated the
forecast mainly to fine tune the sky cover, adjust/endorse the fog
in the river valleys and to add in the T/TD obs and trends for
those grids. These updates have been sent to the ndfd and web


Short term...(this evening through Wednesday night)
issued at 446 PM EDT Tuesday Sep 17 2019

Surface high pressure extends from eastern Canada through the Ohio
Valley, with a quasi-stationary front aligned from the bootheel of
Missouri down across the Tennessee Valley and into the Carolinas.
Aloft, a ridge axis remains positioned along the Mississippi
Valley, with troughing in the west and across the western
Atlantic. Temperatures have been several degrees cooler across
eastern Kentucky today compared to yesterday, thanks to the
modest change in air mass, as well as some scattered cumulus

The models are in good agreement through the short term, with the
ridge axis dampening a bit as it pivots to the east through the
period. This is mainly occurring due to short wave energy moving
quickly from the central rockies to south central Canada through
the period. At the surface, high pressure will build in across New
England, with low level winds gradually veering from the northeast
to the southeast across eastern Kentucky.

Drier and somewhat cooler weather is ahead, as thicknesses lower
across our area through the period. Afternoon cumulus will
dissipate this evening, with temperatures dipping into the upper
50s and lower 60s in the valleys, while ridges stay up in the mid
60s. Areas of valley fog will form after midnight, but should
mainly be confined to the deeper river valleys. Wednesday will
feature another day of scattered cumulus, with high temperatures
a degree or so cooler compared to today. Most locations will see
mid to upper 80s. Similar nighttime conditions are expected for
Wednesday night, with River Valley fog, and lows in the 50s and

Long term...(thursday through tuesday)
issued at 446 PM EDT Tuesday Sep 17 2019

The ridge axis and dry weather will continue to dominate the
weather pattern across eastern Kentucky into the weekend, with
heights increasing once again somewhat through Saturday, before
lowering into early next week, as a trough axis takes aim at the
Ohio Valley. The models continue to disagree on the timing and
amplitude of the smaller scale features later in the period, with
the GFS continuing to show more robust moisture and a quicker
arrival of a surface cold front. The European model (ecmwf) remains slower and more
dampened with the moisture. Given the disagreement, have stuck
close to a blend of persistence and the latest blended guidance.

Dry and warm conditions will continue across eastern Kentucky
through Sunday, with highs generally in the mid to upper 80s, and
lows in the 50s and 60s. Pop chances will increase towards dawn
Monday morning and continue to peak during the day on Monday. Only
slight chance pops were allowed for Tuesday, with the potential
for the frontal boundary to get hung up near or just to our south.


Aviation...(for the 06z tafs through 06z Wednesday night)
issued at 149 am EDT Wednesday Sep 18 2019

With strong subsidence settled in and clear skies in place
overnight, fog is expected to develop in the river valleys.
However, fog will be suppressed and shallow due to the dry air in
place. This should keep the fog out of the taf sites. Thus, expect
VFR conditions across the area through the night with the
exception of the river valleys. Expect light and variable winds of
around 4 to 5 knots through the day. Some diurnal cumulus is also
possible in the afternoon but between 5 and 7 kft.


Jkl watches/warnings/advisories...


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