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FXUS63 KPAH 192007

Area Forecast Discussion
National Weather Service Paducah KY
307 PM CDT Sat Oct 19 2019

.SHORT TERM...(Tonight through Monday night)
Issued at 305 PM CDT Sat Oct 19 2019

Our region is experiencing a pleasant Fall afternoon sandwiched in 
between post Tropical storm Nestor to our southeast and weak 
shortwave energy moving across Missouri and Iowa. Enough mid level 
moisture may sneak into our southeast Missouri counties for some 
sprinkles late this afternoon. There may also be some sprinkles or 
very light showers develop over the Pennyrile of west Kentucky into 
southwest Indiana late this afternoon and evening, associated with a 
plume of low level moisture pushing northward from Nestor. At this 
point not expecting anything measurable due to limited moisture and 
lack of sufficient lift.

Guidance is hinting at some fog possibility tonight with light winds 
in place as weak high pressure resides over the region. As the 
surface high pushes east, southerly return flow develops throughout 
the day on Sunday. This will allow temperatures to boost into the 
mid 70s.

Our attention then turns to a very dynamic system taking shape over 
the Plains tomorrow night. As surface low pressure moves from South 
Dakota/Nebraska into Minnesota Sunday night into Monday, a cold 
front will get drawn eastward across the Quad state region.

There is a possibility that some warm air advection convection 
starts developing closer to midnight or shortly after Sunday night 
across southeast Missouri, far west Kentucky, and far southern 
Illinois. However, the bulk of the precipitation looks to hold off 
until after 3 or 4 AM. A large swath of rain and embedded 
thunderstorms looks to move in from our west and march eastward 
through the morning and early afternoon hours on Monday. Guidance 
continues to trend with the faster solution, which would bring an 
end to the majority of the rain by 18z Monday west of the Wabash 
River and KY Lakes area. Then exiting our east by late afternoon. 
Decided to give some buffer room though, so kept in PoPs a bit 
longer than most guidance suggests currently.

There remains a decent chance for some severe thunderstorms with 
this event. Main time frame looks to be 09-18z Monday, although some 
severe chances may linger in our east until the front makes passage. 
Given strong forcing, impressive wind fields, (850mb jet of 50+ kts 
and 500mb jet of 90+ kts), and a nice surge of low level moisture 
(dew points into the mid 60s) the ingredients appear to be in place 
for a QLCS type event. The wild card will be the amount of 
instability. Although, as of now, most models continue to hint at 
MUCAPE values in the range of 500-1000 J/kg surging into southeast 
Missouri after 06z Sunday night and translating eastward before 
quickly decreasing closer to 18z. This would be more than enough to 
support severe storms (particularly across southeast MO, west KY, 
and far southern IL, where the best probability of higher 
instability exists). Also, strong low level shear looks to be 
present, with 0-1 km shear of 35-40 kts. This would support some 
brief spin up tornadoes along with the damaging wind threat.

A surge of deep moisture from the Gulf will push into our region 
ahead of the front. This will lead to some heavy rainfall potential, 
Current QPF amounts haven't changed much, generally in the 1 to 1.5 
inch range, with some locally higher amounts.

After the front passes, drier and cooler air will move into the 
region Monday night.

.LONG TERM...(Tuesday through Saturday)
Issued at 305 PM CDT Sat Oct 19 2019

To start out the long term period, a large upper level low will be 
located over the western Great Lakes region with a large trough 
carved out across the country's mid section extending all the way 
down to the Gulf Coast states. Strong cold air advection will have 
taken place Monday night and will continue somewhat into Tuesday. 
850mb temperatures will drop down into the single digits so we will 
likely stay in the lower to mid 60s for highs on Tuesday. West winds 
will be a bit brisk on Tuesday as the gradient remains rather tight 
as we remain on the northern periphery of the surface high centered 
over the lower Mississippi River Valley. The main upper trough will 
move east of the area by Tuesday night. The upper flow will become 
northwesterly but then quickly zonal by midweek. With clear skies 
and light winds, lows in the upper 30s to near 40 degrees will be 
likely Tuesday night. 

By about midweek, some upper level energy will be diving south out 
of the northern Rockies and an upper trough eventually develops 
across the Rockies. Winds become southerly on Wednesday resulting in 
an uptick in our high temperatures. Our region ends up in 
southwesterly flow by Wednesday night into Thursday. As this upper 
trough strengthens and eventually swings eastward into the central 
Plains states on Thursday into Thursday night, our rain chances 
definitely will be on the increase sometime in the Thursday night 
into Friday time frame. There will be a period of time where higher 
PoPs will be warranted but given the timing differences, will keep 
them in the chance category. Even though there are some timing 
differences, the operational GFS/ECMWF indicate this to be a rather 
quick hitting system resulting in dry conditions for Friday night 
into Saturday. However, the GFS ensembles are not as quick to move 
the precipitation eastward. 

However, some pretty chilly air is slated to filter into the area on 
Friday behind the system, resulting in highs only in the 50s to 
around 60 degrees. Friday night lows will be back down into the mid 
to upper 30s with Saturday's highs around 60 degrees.


Issued at 1238 PM CDT Sat Oct 19 2019

Generally VFR today and most of tonight. Mid level moisture will 
be increasing over the area over the next 12 hours. Low level 
moisture from the tropical system to our south will lift north 
across KY this afternoon into tonight. There may be some MVFR cigs
or VSBYS after 06z. Kept cigs VFR but could see KOWB and possibly
KPAH/KEVV seeing some MVFR cigs later on. Will continue to 
monitor. Low level moisture will be firmly in place by Sunday 
resulting in low VFR cigs. Sprinkles of rain will be possible this
afternoon and evening over the KY Pennyrile region, and this 
afternoon across southeast MO. Winds will be aob 10 kts.



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