Area forecast discussion
National Weather Service Paducah Kentucky
619 PM CDT Sat may 18 2013
Update...
issued at 614 PM CDT Sat may 18 2013
Update for 00z aviation only
&&
Short term...(tonight through Monday night)
issued at 306 PM CDT Sat may 18 2013
With whats left of an upper low just to the north and east of our
County Warning Area...scattered showers are possible this afternoon into the early
evening hours over the extreme northeast sections of our County Warning Area.
Models continue to indicate a scenario tonight that still makes no
sense...but all models are showing (for the most part) the same
thing. They show a northwest-southeast oriented surface trough draped across our
County Warning Area...an 500 mb ridge building across the area...and a northwest-southeast oriented
band of light precipitation/quantitative precipitation forecast developing along and/or near the
boundary. Normally a ridge building overhead tends to
squash/suppress any chances for precipitation...but with the
presence of the surface trough and the fact that all models continue to
crank out a band of light precipitation...decided to keep small probability of precipitation
overnight into Sunday morning just in case.
Dont expect any precipitation Sunday afternoon and evening...but with the
ridge having moved to the east of the area...it will allow precipitation
chances to make their way back into the far northwestern and western
sections of our County Warning Area late Sunday night as the next weather system
approaches from the Central Plains. As the system draws nearer to
the lower Ohio Valley...precipitation chances will increase Monday
into Monday night.
Long term...(tuesday through saturday)
issued at 306 PM CDT Sat may 18 2013
European model (ecmwf)...GFS and Gem all show a surface low over the upper Midwest
00z Wednesday...moving over the lower Great Lakes region by 00z
Thursday. Gem is bit faster than the European model (ecmwf) with the associated cold
front and precipitation timing. GFS is a little slower than the European model (ecmwf) and
less defined with precipitation ending because it develops a second low
which slides along the front late Wednesday night into early
Thursday. This GFS solution is not consistent with its previous
run...and preferred to lean toward a European model (ecmwf)/Gem solution. Shower and
thunderstorm chances will increase from west to east on Tuesday with
the approach of the front...with the best chances for more
significant quantitative precipitation forecast Tuesday night into Wednesday. Went with likely probability of precipitation
for the entire pah forecast area Tuesday night...with likely probability of precipitation
continuing for our eastern third of counties on Wednesday. Models
indicate the front will stall out over or just south of the forecast area for
Wednesday night into Thursday night...so kept some slight to low
chance probability of precipitation in the forecast for these time periods.
Gem and European model (ecmwf) both show high pressure building south out of
central/eastern Canada Friday and into the weekend. GFS also shows
this feature...but is much slower building it south and thus hangs
on to light precipitation in the area into Friday. Leaned toward to the
more aggressive European model (ecmwf)/Gem solutions and went with dry conditions
Friday into Saturday. The high will keep the area in a northerly
flow...which will provide cooler conditions with slightly below
seasonal normals into at least the first part of the Holiday
weekend.
&&
Aviation...
issued at 614 PM CDT Sat may 18 2013
MOS guidance is trying to bring MVFR fog in by sunset at most
sites. Was not ready to go that far but considering last nights
fog went ahead and introduced it. In contrast to normal MOS
actually brings pah evv and owb down earlier and into IFR Cat
overnight. Introduced MVFR fog and tempo some IFR fog after 6z. Will
monitor closely for fog development timing and intensity. Light
south winds overnight and a bit gusty at kcgi after 18z Sunday.
&&
Pah watches/warnings/advisories...
Illinois...none.
MO...none.
In...none.
Kentucky...none.
&&
$$
Update...kh
aviation...kh
