000
FXUS63 KPAH 172312
AFDPAH

Area Forecast Discussion
National Weather Service Paducah KY
512 PM CST Sun Feb 17 2019

.UPDATE...
Updated aviation section for 00z taf issuance

&&

.SHORT TERM...(Tonight through Tuesday night)
Issued at 330 PM CST Sun Feb 17 2019

Main weather story in the short term is with the potential for
another heavy rainfall event later Tuesday, and esp Tuesday night
into Wed.

Tonight through Monday and Monday night, we will main be dealing
with precip free conditions as a 1040 mb high pressure dome slides
slowly east from the northern Plains and Midwest into the Great
Lakes region. However, Stubborn cloudiness will likely hang on
through much of the night, and contrary to what some models
suggest, may last well into Monday. With the chilly high pressure
system lurking off to the north, temperatures will be a below
normal through the short term, with highs only from the mid 30s to
lower 40s Monday, and from near 40 to the mid 40s on Tuesday.

By late Tuesday afternoon, widespread rains are expected to
spread from south to north across the forecast area as the mid
level flow turns more swly and over-runs the low level cold air
dome. The good news in that it current looks as though the area
will warm enough Tuesday to support only liquid precip. And
temperatures Tuesday night should also remain above freezing,
though it will be in the mid 30s to near 40 at most locations.
There could be some wet snow at the start of the precip Tuesday
evening up along the I-64 corridor, but that should fairly quickly
transition to a cold rain as temperatures aloft warm with the
help of 30-40kts southerly flow.

As a fairly deep mid level trof digs east toward the western high
Plains, and swly flow aloft increases Tuesday night into early
Wednesday, rainfall rates will increase as well. PWATs will climb
into the 1.10" to 1.25" range overnight Tuesday, near the 99th
percentile compared to the climatological norms for this time of
year. Highest PWATs and expected rain totals are expected to occur
from the MO Bootheel up through much of western KY. Could see a
good 1.5 to 2.5 inches of rainfall by Wednesday morning, highest
over the southern Pennyrile region of western KY. Will go with a
Hydrological Outlook (ESF) with this package to address expected
impacts, esp with respect to areal flooding and river flooding
issues.

.LONG TERM...(Wednesday through Sunday)
Issued at 330 PM CST Sun Feb 17 2019

A little less confidence in the extended as the models are starting
to diverge from previous runs. Mainly the ECMWF with its more
northerly path of precipitation.

The GFS and parallel FV3 take the rain southeast and out of the area
Thursday as does the Canadian. So will weight the forecast a little
more to the later models mentioned. Most of the ensembles support
the later scenario but there are some that favor the ECMWF solution.
Will obviously go with a blend which is producing low pops. Will
also go with low qpf so impacts should be at a minimum at least for
that time frame. However we could mix with or change over to snow.
But the available moisture will be very limited so again very little
if any impact Thursday night. Friday and Friday evening will be a
brief respite from the rain as high pressure drifts through the
region. Now for the weekend that will be a different story. There is
not a lot of qpf in the grids right now but I have a feeling we will
be adjusting that after WPC coordination call this afternoon. The
southwest flow will usher in another low only this time it will be
just ahead or in tandem with a fairly strong upper level trough.
Again the models differ with their strength of this upper level
system. The ECMWF is much more intense with a sharp trough moving in
from the west with a closed low forming as it moves through the
plains. The GFS actually has an open wave move through much faster
and weaker. One good thing is temperatures will be much warmer than
previous...so there will be little to mention of wintry precip
impacts in the extended.

&&

.AVIATION...
Issued at 512 PM CST Sun Feb 17 2019

Main forecast concern is the low clouds that persist across our
region. Drier northwest winds have resulted in patches of clearing
in southeast MO. However, large areas of mvfr cigs still hang back
to the Kansas border as of 23z. Based on the slower clearing trend
in satellite loops, the clearing trend will be delayed in the tafs.
In fact, cigs will remain in the mvfr category for the entire taf
period at kmvn, kevv, and kowb. Improvement is still forecast at
kcgi/kpah tonight, but the slower timing of the forecast may need to
be slowed even further in later tafs. Winds will be northwest around
10 kt through the period.

&&

.PAH WATCHES/WARNINGS/ADVISORIES...
IL...None.
MO...None.
IN...None.
KY...None.
&&

$$

SHORT TERM...MEFFERT
LONG TERM...KH
AVIATION...MY