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fxus63 kpah 201133 
afdpah

Area forecast discussion
National Weather Service Paducah Kentucky
533 am CST Wed Nov 20 2019

Update...
issued at 533 am CST Wed Nov 20 2019

Several locations in southeast Illinois have developed dense fog
in the last hour or so. Will let the dense fog advisory ride for
now.

The aviation section has been updated for the 12z taf issuance.

&&

Short term...(today through Friday night)
issued at 306 am CST Wed Nov 20 2019

The low stratus over southwest Indiana has been slowly inching
southwestward and is not likely to relent prior to sunrise.
Although visibilities in southeast Illinois have dropped to a mile
or so briefly at a few locations, the advertised dense fog has
not developed yet, despite temperatures dropping several degrees
lower than most guidance indicated. Perhaps there is just enough
wind off the surface to keep it from setting in. That wind should
continue to diminish so we will not give up on the advisory at
this time. Did make a pair of adjustments to account for the
stubborn stratus layer. Added Edwards County Illinois to the
advisory and removed Warrick and Spencer counties in Indiana.

Nothing but high clouds increasing from the west today, so
temperatures should climb back above normal with at least 60
expected over the western half of the area. Of course the
stubborn stratus layer could hold temperatures down considerably
in the northeast if it decides to hang out through the morning.

The models still bring a band of showers with a mid/upper-level
disturbance through our region mainly Thursday morning. A few
showers may reach our western/northwestern counties before 12z,
but for the most part it should pass through the area 12z to 18z.
As the disturbance and surface low lift well northeast of the area
by 18z, the showers should dissipate as they move through west
Kentucky where some areas may not get measurable rain.

The general consensus for Thursday afternoon is for a lull in the
precipitation. The cold front will enter the northwest by 00z
Friday and then will make it through the entire area by 12z
Friday. There will not be much precipitation with the cold front
initially, but showers/rain will develop/spread eastward behind
the front through at least southeast Missouri in the evening. It
will continue to spread eastward over the entire area overnight
with southern portions of the area receiving around an inch with
the main swath of heavier rains.

The rain is expected to shift southeast of the area Friday
morning, leaving the afternoon mostly dry. North winds will not
be that strong behind the front, so temperatures will climb back
into the 40s and lower 50s during the day.

The 00z guidance is in better agreement then in bringing a closed
upper low eastward into the middle and upper Mississippi Valley
Friday night. Although the low is not that strong, it sure looks
like it should be able to draw some moisture back to the northwest
through our region Friday night. This should mostly be rain with
low temperatures mainly in the middle 30s across the region.
Some mix of snow and rain showers is forecast over portions of
southern Illinois and southeast Missouri overnight, but there
should be little to no impact from any snow that falls. We will be
keeping an eye on this system, and if it intensifies or surface
temperatures trend cooler, then it may become a bit more of an
issue.

Long term...(saturday through tuesday)
issued at 306 am CST Wed Nov 20 2019

At the start of the weekend, a closed upper level low and positively
tilted trough will be situated to our northwest. This system will
slowly migrate eastward over our region on Saturday. There
continues to be enough evidence to support some lingering
precipitation as this occurs, as there does seem to be enough
moisture to warrant some scattered pops especially during the
morning hours. Higher chances will be across the eastern half of
the County Warning Area. Looking at critical thicknesses and soundings, models are
still not agreeing the degree of colder air moving in nor the
timing. Therefore, we will have to continue the mention of frozen
precipitation at least for northern parts of the area mainly for
the morning hours.

Precipitation chances really drop off during the afternoon and into
the evening hours as the system moves off to the northeast. The rest
of the weekend appears dry but not as cool with highs in the upper
40s to lower 50s. We will see this somewhat warmer weather (highs in
the 50s) continue into early next week. Models are having a terrible
time with a developing system out to our west. However, it looks
like we will see increasing chances for precipitation as we head
into Tuesday and Tuesday night. Models are just having a hard time
resolving some energy that will arrive on the West Coast by the end
of the weekend and how it evolves with time as it moves east across
the Central Plains states.

&&

Aviation...
issued at 533 am CST Wed Nov 20 2019

The MVFR ceilings have pushed slightly southwest and will impact
kevv and kowb for at least a few hours to start the day. Just
southwest of the low clouds a narrow zone of dense fog has
developed, but only lighter fog will potentially impact the other
taf sites early this morning. Once the fog and low clouds
dissipate later this morning, VFR conditions will prevail through
the end of the forecast period. Late tonight, the low-level flow
will increase substantially leading to low level wind shear potential at least
over the western sites. Eventually, southerly surface winds may
become gusty toward the end of the period. This would most likely
impact kcgi in the last hour or two of the forecast.

&&

Pah watches/warnings/advisories...
Illinois...dense fog advisory until 9 am CST this morning for ilz075>077-
080>083-085>087-091.

MO...none.
In...dense fog advisory until 9 am CST this morning for inz085-086.

Kentucky...dense fog advisory until 9 am CST this morning for kyz010-
014>016-018>021.

&&

$$

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