Paducah NWS Discussions

Forecast Discussion for PAH NWS Office
000
FXUS63 KPAH 231123
AFDPAH

Area Forecast Discussion
National Weather Service Paducah KY
623 AM CDT Thu Sep 23 2021

.UPDATE...
Issued at 623 AM CDT Thu Sep 23 2021

Updated for 12Z aviation forecast discussion.

&&

.SHORT TERM...(Today through Saturday night)
Issued at 312 AM CDT Thu Sep 23 2021

Latest surface indicates a sprawling area of high pressure
stretching from Texas up through the Missouri valley into eastern
Ontario. The system that impacted eastern parts of our area
yesterday, is now affecting the eastern U.S. The center of this high
pressure will slowly migrate eastward today to where it will be
directly over our area by 00Z Friday. While we may see some gusty
winds up in the southeastern Illinois area into southwest Indiana
early today, we should be seeing those winds calming down by
afternoon and especially by early this evening. With a mostly sunny
sky (some cumulus development likely due to some moisture around
850mb) and low humidity, it should be a stellar day with highs in
the low to mid 70s with the higher readings in southeast Missouri,
like yesterday. Given the dry air mass in place and how warm western
parts of the area got yesterday, have raised temperatures a few
degrees higher than the NBM in places for today. We will be starting
out colder than what we did Wednesday morning but full sunshine will
help. Temperatures tonight into tomorrow morning should drop off to
similar values experienced this morning, with readings in the mid to
upper 40s.

Tonight into Friday, the surface high will move eastward as another
cold front approaches from the northwest. Winds will shift around to
southwest and some warm air advection will result in a bump in low
temperatures with it only getting down into the mid 50s Friday
night. High temperatures on Friday will also rebound a bit into
the upper 70s to near 80 degrees as warm air advection continues.
Again, went a few degrees higher than the NBM again given the jump
in 850mb temperatures expected. We will see a bit of an uptick in
low level moisture as well, so it may feel a touch more humid but
dew points will stay in the 50s.

The aforementioned cold front will enter the area around 06z
Saturday and move across the area during the overnight hours and
exit on Saturday morning. Models are fairly consistent with the main
chances of rain being confined to southern Illinois, southwest
Indiana and adjacent parts of west Kentucky, where the deeper
moisture is projected. Any lingering rain and clouds should quickly
depart the area early Saturday morning resulting in rapidly
improving weather conditions across the entire region. Somewhat
cooler air arrives behind the front with northwesterly flow, but
highs on Saturday will still be in the 75 to 80 degree range.

.LONG TERM...(Sunday through Wednesday)
Issued at 312 AM CDT Thu Sep 23 2021

There aren`t any significant forecast concerns in the long term
portion of the forecast with dry weather expected through the middle
of next week. Forecast confidence starts off higher than average
over the weekend, but does trend somewhat lower through the end of
the period.

The upper level pattern across the country through the first half of
next week is forecast to transition from one with a broad ridge in
the west and trough in the east, to one with troughing in the east
and west, and ridging across the nation`s mid section. At the
surface, southerly flow will develop on Sunday as a warm front lifts
north of the region. Those south winds should persist into at least
Tuesday, when things become a little less certain.

As we head into mid week, models appear to be split into two main
camps. The GFS and a majority of its ensemble members bring the
ridge further east into the Mississippi and Ohio Valleys while
maintaining southerly flow at the surface. This results in warmer
than normal temperatures. Meanwhile, the ECMWF, Canadian, and a
majority of their ensemble members keep the ridge further to the
west, which maintains northwesterly upper flow and allows for the
passage of a dry cold front Tuesday into Wednesday. This yields much
cooler temperatures by Wednesday and Thursday.

At this time, the initialized NBM approach appears to lean in the
direction of the warmer GFS through most of the period. As a result,
daytime highs are forecast in the lower to middle 80s, and nighttime
lows in the upper 50s to lower 60s. Of course, these values may be a
bit warm, especially by mid week, should the cooler ECMWF and CMC
come to pass. Otherwise, dry weather is forecast through the period.

&&

.AVIATION...
Issued at 623 AM CDT Thu Sep 23 2021

Clear skies and light winds may still allow some river fog
development early this morning, primarily along and west of the
Mississippi River. By late morning, NW winds will increase into
the 8-12 kt range. Strongest winds look to be over the KEVV/KOWB
areas, which may experience 15-20 kt gusts as well. Winds become
light and variable after 00z.

&&

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

$$

NWS PAH Office Area Forecast Discussion

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