Area Forecast Discussion
Issued by NWS Paducah, KY

Home | Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37

FXUS63 KPAH 210800

300 AM CDT Mon Apr 21 2014

.SHORT TERM...(Today through Wednesday night)
Issued at 300 AM CDT MON APR 21 2014

Radar shows some light showers/sprinkles moving into our far
western counties, with more showers developing across north central
Arkansas. Models show precip spreading across the PAH forecast
area through the day into this evening. ECMWF is the fastest and
NAM the least aggressive, but overall the general timing is in
pretty good agreement with fairly widespread precip across the
entire fa by 00z. The western half of the fa should see the best
chances late this afternoon into the early evening hours, and the
eastern half late this evening into the early morning hours, and
went with likely pops for these periods. Best thunderstorm
chances will be during the daytime hours when there is the best
instability, but some thunderstorms will remain possible into this
evening with LIs still around 0 to -1. Showers will quickly taper
off from northwest to southeast between 03z and 12z Tuesday, with
just a few showers lingering in our far southeast counties early
Tuesday morning.

High pressure will build over the upper Mississippi valley Tuesday,
sliding slowly east over the Great Lakes region by Wednesday.
Winds out of the north on Tuesday will gradually shift to the east
by Wednesday, which will help give us cooler, near seasonal
conditions. The region should see quite a bit of sunshine by
Tuesday afternoon and again on Wednesday with dry air in place
over the area. Clouds will increase late Wednesday night with
increasing moisture ahead of our next weather system.

.LONG TERM...(Thursday through Sunday)
Issued at 300 AM CDT MON APR 21 2014

Thursday, models continue to forecast the eastward progression of a
low at h5 along the US/Canadian border, northern tier of states, to
generally the Great Lakes Region by 12z Friday. Attendant trof axis
and associated surface frontal boundary will provide forcing
coincident with an axis of moisture along and ahead of the features,
resulting in a chance of showers and thunderstorms moving west to
east across the area Thursday into Thursday evening. GFS remains
slightly faster. The new 00z ECMWF has slowed slightly, but still has
the activity gone by 06z Fri, or so. PoPs may eventually need to be
higher with this event. But for now, given timing and coverage
questions, capped PoPs at high chance for now.

Friday through Saturday should be mainly dry. We trended the
sensible weather elements and such toward a consensus of the
GFS/UKMET and GEM, as the ECMWF becomes the outlier. By 144 hrs (00z
Sun), its mid tropospheric depiction is much less amplified,
especially with the ridge over the mid CONUS. As a result it keeps
high pressure farther north, and warm sectors us more quickly
early in the weekend. The consensus of the other 3 models brings
high pressure south and through the area through Saturday. And,
there is some question as to whether or not the boundary will head
back to the north, and if so, how far. Probably some, but it`s not
clear at this time. Will monitor Friday night for slim chance PoPs
along and just behind the frontal boundary. Again, going dry for
now Fri-Sat, then slight chance PoPs Sat night, chance PoPs
Sunday, with potential overrunning rains/elevated convection
spreading northeast. Temps will be a blend of previous numbers to
start, then will hedge toward GFS/GEM, MOS influenced guidance
minus the ECMWF output for the end of the long term (toward the


Issued at 300 AM CDT MON APR 21 2014

Mid level clouds will increase across the TAF sites from the west
today with increasing chances of showers and some thunderstorms,
especially this afternoon into this evening. MVFR conditions will
be possible with any precipitation. Winds will be out of the
southwest at 6 to 12 kts, shifting to the northwest late in the
TAF period.




AVIATION...RST is the U.S. government's official web portal to all federal, state and local government web resources and services.