Scientific Forecaster Discussion

Return to Local Conditions & Forecast

Without Abbreviations
With Abbreviations

Area forecast discussion 
National Weather Service Paducah Kentucky
326 am CDT Friday may 29 2015

Short term...(today through Sunday night)
issued at 326 am CDT Friday may 29 2015

Over time...probability of precipitation ramp up slowly/but surely as open swlys continue
to moisten the column in full. When mean northern stream vorticity maximum/upper
trough dives into Great Lakes from Canadian interior provinces...it
will drive attendant cold front into/through middle MS valley. As all
this comes together...Saturday looks to be wettest day in short
term as the front dives to along/around about the Ohio River by
00z Sunday.

We will continue to be dealing with a slowly departing frontal
boundary on Sunday. The latest model trends push the front right
on through the area and into the Gulf states. As such...most
models are drier with quantitative precipitation forecast amounts Sunday into Sunday night. Will
reduce probability of precipitation considerably...especially over our north/west counties. If trends
continue...may need to reduce more over central/south areas with
time. Will also remove thunder risk at this time for Sunday/Sunday
night time frame. Temperatures Sunday will be in the cooler 60s and 70s
behind the front.

Long term...(monday through thursday)
issued at 326 am CDT Friday may 29 2015

As the pah forecast area will be under the influence of nnerly low
level winds and higher surface pressures...much of the deep moisture
from the weekend should be shunted eastward out of the pah forecast area
by early next week. Whatever precipitation chance exists Monday should taper off
even more after sunset. Even thunderstorm chances appear very limited Monday
due to lack of instability and increasing middle level ridging. This
should be true through middle week...as the medium range models seem to be
in reasonable agreement with their solutions depicting an expanding
middle level ridge across the eastern Continental U.S. And a digging western trough.

An exception to the eastern ridging will be a weak middle level low which
the medium range models...with less certainty/consistency with
time...show cutting off somewhere over the deep South/Florida by middle week
on at least. By Wednesday...low level winds in our region are prognosticated to
return to the south. This will tend to increase lower tropopause
instability...and the weak low may eventually cause additional
deeper moisture to surge into the pah forecast area from the south
late in the week...with the source region being the Atlantic. Not
all models have this solution however. With no significant low level
forcing mechanism...an increasing diurnal signal for showers and
thunderstorms was indicated in the initialization blend through day 7 (thu).
This seemed like a reasonable forecast...with probability of precipitation no higher than 40
middle week on.

Temperatures will be on the warm side of average for this time of year...
especially late in the extended period.

&&

Aviation...
issued at 1140 PM CDT Thursday may 28 2015

VFR conditions expected at all sites through the period...however
VFR ceilings and thunderstorms in the vicinity possible after 09z and 15z respectively as a
weather system begins to emerge from the plains. Slightly better
chances for thunderstorms and rain after 18z but did not want to include thunderstorms and rain in a
from group for so many hours...so just decided to go with a thunderstorms in the vicinity for
now. Southerly winds at or below 10 knots at all sites through the period.



&&

Pah watches/warnings/advisories...
Illinois...none.
MO...none.
In...none.
Kentucky...none.
&&

$$

Short term...GM
long term...db
aviation...jp

National Weather Service Glossary of Abbreviations