Scientific Forecaster Discussion

Return to Local Conditions & Forecast

Without Abbreviations
With Abbreviations

fxus63 kpah 171330 
afdpah

Area forecast discussion
National Weather Service Paducah Kentucky
730 am CST sun Nov 17 2019

Update...
issued at 728 am CST sun Nov 17 2019

For aviation section only.

&&

Short term...(today through Tuesday night)
issued at 330 am CST sun Nov 17 2019

Just a couple of minor systems expected to affect the forecast
area during the short term, resulting in more in the way of cloud
cover than actual precipitation. Temperatures are expected to
remain near or slightly below normal most of the period, with a
bit of a moderation possible by Tuesday.

The first system comes in the form of a mid/upper level trof that
will be digging southeast across the plains today and then into
the mid MS/lower Ohio Valley regions tonight. However, expected
sfc/low level reflection is minimal and will not result in much
forcing in the lower atmosphere. Could be some very light rain
this evening, mainly over portions of southern IL, but it should
not amount to more than a few hundredths.

Monday should be precip free as a weak surface ridge transitions
east across the region. Then a weak clipper-type system will dive
southeast through the plains and into the forecast area Monday
night. Once again, more clouds than precip can be expected with
its passage, as overall forcing looks weak.

Hoping to get back to some sunshine in the wake of the system on
Tuesday as high pressure builds in from the west. This high will
not be of Canadian origin, and temperatures may actually climb to
near or slightly above normal levels by Tuesday afternoon.

Long term...(wednesday through saturday)
issued at 330 am CST sun Nov 17 2019

On Wednesday, an upper level ridge will be building into the area,
resulting in dry and warmer conditions across the area. Fairly
strong warm air advection will be taking place as surface winds
become southerly, as a surface high moves toward the East Coast
during the day and our next system approaches from the west. With
low level temperatures increasing as this occurs, would not be
surprised to see readings in the lower 60s for many locations.

Our next weather system will making its way eastward during the day
on Wednesday and likely impact the area Wednesday night into
Thursday. A low pressure system will develop over the Central Plains
states early on Wednesday and move northeast and end up in the upper
Midwest/Great Lakes region by Thursday afternoon. As this occurs, a
cold front will March eastward through the region on Thursday.
Precipitation will develop out ahead of the front and start
impacting far western portions of the area as early as Wednesday
evening, with precipitation chances overspreading a good portion of
the area after midnight Wednesday night into Thursday morning. It
appears the best chances on Thursday may be in the morning hours as
the quantitative precipitation forecast really drops off after 18z, as the deeper moisture moves
east. Will taper off pops Thursday afternoon to where the best
chances will be confined to southwest in and west Kentucky.

On Thursday night, a secondary low tries to develop along the front
as it continues to slip further south and east, which may result in
renewed precipitation development mainly across our southern
counties Thursday night into Friday. Will likely be a tight pop
gradient between US and our neighbors to the south. We will have to
monitor the evolution of how the upper pattern will unfold by late
in the week, as this has ties to the where exactly additional precip
chances re-develop. The newest Euro/Canadian indicate a more dry
pattern late Thursday night into Friday, while the latest nbm and
ensemble data reflect what we have going in our latest pop grids. We
will see much cooler high temperatures on Friday behind that front
with readings in the upper 40s to lower 50s.

Another upper level disturbance advances eastward Friday night into
Saturday, bringing additional precipitation chances. Depending on
how temperatures work out, we could see a wintry mix during this
time frame, but confidence is low at this time.&&

Aviation...
issued at 1130 PM CST Sat Nov 16 2019

In light of the lowered wind speeds and moisture convergence in
and near the surface ridge axis and weak inverted trough oriented
southwest to northeast across the weather forecast office pah taf sites, had to
reconsider the inclusion of fog in the 06z Sunday weather forecast office pah taf
issuance.

Was somewhat spooked by the late onset of fog Saturday morning,
likely due to stronger winds and a greater temperature/dewpoint
spread. However, that is not the case tonight. In coordination
with my fellow forecaster working on the gridded elements of the
forecast, allowed for the mention of fog in the taf's. At this
point, kept most of the visibilities in the VFR and MVFR range
through Sunday morning.

A fast moving trough/shortwave in the upper Midwest and rockies
will quickly dive southeast on Sunday, helping to lower ceilings
Sunday afternoon and evening into the lower VFR category.

For the most part, the weather forecast office pah taf's will remain in the VFR
category, with minor incursion of ceilings and visibilities into
MVFR category.

&&

Aviation...
issued at 730 am CST sun Nov 17 2019

A fast moving trough/shortwave in the upper Midwest and rockies
will quickly dive southeast on Sunday, helping to bring an icrease
in VFR ceilings Sunday afternoon and evening. Winds will be light
west to NW during the day.

&&

Pah watches/warnings/advisories...
Illinois...none.
MO...none.
In...none.
Kentucky...none.
&&

$$

National Weather Service Glossary of Abbreviations