Area forecast discussion
National Weather Service Jackson Kentucky
302 am EDT Sat may 25 2013
Short term...(today through sunday)
issued at 133 am EDT Sat may 25 2013
A surface ridge of high pressure stretching from Ontario to the
Carolinas will remain nearly stationary during the period...bringing
US a dry surface air mass. We will have nearly neutral or slight
cold air advection. With an unusually cold air mass initially in
place...the lack of significant cold air advection will allow strong
late Spring sun to begin to warm and modify the air mass.
Flow between the eastern Continental U.S. Ridge and low pressure over the High
Plains will result in warm air advection over the plains and Midwest.
This was already causing thunderstorms over Iowa on Friday night.
Additional rounds of convection are expected over the upper Midwest
through Sunday. Moisture/debris clouds from that area will be carried
southeast by the flow aloft. This will bring an increase in clouds
locally. Can not rule out precipitation late tonight or Sunday...but virga
is the more likely scenario with our dry surface air mass in place.
Will carry just a chance of sprinkles tonight and Sunday.
Long term...(sunday night through friday)
issued at 300 am EDT Sat may 25 2013
The models were in better agreement this go round. Overall the
weather in the extended will be dominated by a large ridge of high
pressure. This weather system will bring warm and dry weather to
eastern Kentucky for most of the week. The exception could be the
Sunday night through Monday night time frame. The GFS...ECMWF...and
sref models all have isolated showers and storms forming over the
northern half of eastern Kentucky Sunday night into Monday night...as a
weak and ill defined frontal boundary drifts slowly northward across
the area and into the Ohio Valley. That has been the case for several
model runs now...so decided to leave in a slight chance of rain for
the first few periods of the extended. The model soundings did indicate
that enough instability would be present for a storm or two to
form...particularly during the afternoon and evening hours on Monday.
After Monday night...a very large and strong ridge of high pressure
is prognosticated to settle over the area. The sinking air...and subsequent
drying in low and middle levels...will lead to strengthening high
pressure at the surface and aloft and steady warming from Tuesday
Onward. Temperatures from Tuesday through the end of the week will
likely warm to above the mexmos guidance values...as high pressure
strengthens and cloud cover is at a minimum and southerly winds
become established. Adjustments were made to the temperature forecast
based on the aforementioned reasoning. The warmest days of the week
will be Wednesday through Friday...as high pressure will be at its
peak intensity.
&&
Aviation...(for the 06z tafs through 06z Saturday night)
issued at 133 am EDT Sat may 25 2013
VFR and light winds are expected through the period.
&&
Jkl watches/warnings/advisories...
none.
&&
$$
Short term...hal
long term...Arkansas
aviation...hal
