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Area forecast discussion...updated 
National Weather Service Paducah Kentucky
1221 PM CDT sun Apr 19 2015

issued at 1210 PM CDT sun Apr 19 2015

Updated the aviation discussion for the 18z taf issuance.


Short term...(today through Tuesday night)
issued at 147 am CDT sun Apr 19 2015

The new swody1 greatly downplays the severe risk for our forecast area...and
this looks agreeable with the instabilitly fields/better shear to
our south. Still...we warrant a marginal mention...with the
surface waves lifting across the middle MS valley later
today-tonight in a high pop event.

Probability of precipitation should taper west-to-east on Monday as the waves lift out. By
00z Tuesday...high pressure at the surface is building in and will
expand its reach across the lower MS valley through Monday night
while we remain under the influence of the upper trough. This will
result in a cooldown from 70s/50s 60s/40s for Monday
and Tuesday.

The high shifts eastward to the southeast U.S. And the zonal flow pattern
underneath the broad NE U.S. Trough brings our next chance of precipitation
to the area by late Tuesday-Tuesday night.

Long term...(wednesday through saturday)
issued at 207 am CDT sun Apr 19 2015

Models appear to be gradually coming together on a more unified
solution middle week. Model agreement is also better in the late
week...though timing is still off by 12 to 18 hours. As a result...
forecast confidence has improved to better than average during the
long term.

An upper level low is prognosticated to be centered over southern Ontario
province in Canada Wednesday morning. This low is forecast to track
slowly east into northern New England through the end of the week.
Entrenched in the cyclonic northwest flow on the back side of this
low...the immediate forecast area will experience a cooler than
normal pattern through the remainder of the week. While daytime
highs are forecast to reach the middle to upper 60s on Wednesday...
lower to middle 60s should be more typical through the rest of the
week. Nights will be chilly with lows in the 40s.

Small precipitation chances remain in the forecast Wednesday and
Wednesday night as a reinforcing cold front sinks south through the
area. Given the model instability forecast...will add a chance of
thunder across the entire region Wednesday...and across the southern
half Wednesday night. With the exception of a lingering morning
shower Thursday...mainly dry conditions are now expected in the wake
of the frontal passage Thursday...Thursday night...and through much
of Friday as high pressure builds south from Canada.

Rain chances still look better by the weekend as the next wave
progresses east from the Central Plains into the middle Mississippi
Valley by Saturday. As mentioned earlier...model timing is still not
quite in sync...but at least part of the weekend looks wet.


issued at 1210 PM CDT sun Apr 19 2015

IFR/MVFR ceilings and vcsh early should improve to VFR this afternoon
into the evening hours...then diminish back to MVFR/IFR with
rain showers/thunderstorms and rain overnight through early Monday morning...then gradual
improvement the last few hours of the forecast. South to southwest
winds at or below 10 knots will prevail through most of the period...then
veer around to the west to northwest at 12-14 knots gusting up to
24 knots in the wakr of a frontal passage.


Pah watches/warnings/advisories...


Short term...dh
long term...rjp

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