Area Forecast Discussion
Issued by NWS Paducah, KY

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FXUS63 KPAH 220702

Area Forecast Discussion
National Weather Service Paducah KY
202 AM CDT Wed Mar 22 2017

.SHORT TERM...(Today through Friday night)
Issued at 146 AM CDT Wed Mar 22 2017

While the frontal boundary is well south of the FA now, there is
still some overrunning convection affecting/departing our southern
counties...but it is tracking to leave the FA pcpn free by/before
12Z. After that, upper ridge builds to our west, with H5 height
rises upwards to 40DM occurring over the heart of the FA, even as
broad surface anticyclone anchors across Great Lakes, and extends
its influence southward into the lower Ohio valley with
cooler/drier Canadian CP airmass. We think this combo effectively
eliminates Pops for us, although we acknowledge a lingering
boundary that could touch off some instability showers just to our
south and west, thru the day/night.

On Thursday, the mean upper ridge migrates eastward and anchors
across the Mississippi river valley, while strong height falls are
noted in the Desert Southwest, in response to a strong upper
jet/digging Long wave. This backing upper flow will stream ample
moisture southwest to northeast across the southern Plains,
allowing for convection/pcpn to initiate as the mean upper stream
jet energy spawns Lee side cyclogenesis. This developing/evolving
system effectively tracks due eastward across the Red River
valley by Friday, on a bee line to the lower Mississippi river
valley, which has by now seen its mean ridge slide eastward to the
southeast U.S. Old SWODY4 outlooks 15% svr threat for
Friday-Friday night time period just to our south and west, as
this system comes into play, and it`ll be something to keep an eye
upon as the end of the week draws near.

Coolish temps today-tonight (50s/30s) will moderate Thursday
(60s/50s) as we transition from the Trof to the Ridge. We`ll reach
into the 70s Friday in the warm sector, ahead of the next weather
system, as pcpn/thunder chances return.

.LONG TERM...(Friday through Tuesday)
Issued at 316 PM CDT Tue Mar 21 2017

Upper low at the beginning of the period over the TX/OK Panhandle
region still forecast to move ENE, ending up over MO by 00z Sun. The
slightly slower CMC, GFS solutions were used with some EC
incorporation. Increasing chance of convection later Friday and
Friday night, peaking Saturday, then diminishing Saturday night
through Sunday as the upper system heads toward the Great Lakes /
Ohio Valley regions.

This initial system will be followed quickly by another H5 trof /
weaker low, spreading convective chances back across the area by
Monday, continuing into Monday night. We used a blend of EC/GFS and
ECENS MOS for temps, with weight given to existing numbers as


Issued at 146 AM CDT Wed Mar 22 2017

Nearby pcpn echoes on radar remain south of the terminals, and
should not impact the terminal forecast as the overrunning
boundary is keyed well to the south and will remain so. Mid and
high clouds will gradually thin/disperse with time, as
cooler/drier Canadian CP airmass works down/across the river
valley from the north/east.




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