Scientific Forecaster Discussion

Return to Local Conditions & Forecast

Without Abbreviations
With Abbreviations

Area forecast discussion 
National Weather Service Jackson Kentucky
1042 am EST Thursday Nov 27 2014

issued at 1042 am EST Thursday Nov 27 2014

A morning of light snow showers and soon becoming mixed with rain
shower activity will continue through the morning with the heavier
activity continuing in the east through the afternoon. With the
exception of brief break of cloud as of 1515z over the
Ohio River bordering in and cover will continue to be over
eastern Kentucky...especially assisted by the perfect trajectory in
the wind flow for upslope. Though despite previous events in this
pattern...activity is quite moisture starved and the anticipated
continued cloud cover...with a few breaks through the day...should be
enough to temper the high temperatures advertised. Because of
this...have dropped high temperatures for the day a couple
degrees...especially with a weak...though noticeable cooler air mass
behind this front and a secondary front. This mentioned second front
is pretty much discounted by the models making it far enough south to
impact eastern Kentucky. However...on of the few models...the hrrr
and current trends might suggest this front bringing some flurries
and or sprinkles to the area this evening and into tonight. As well
assisting on the increased cloud cover. Have updated the forecast to
account for these highlights as well as a fresh severe weather potential statement prolonging the
snow a bit more.

Update issued at 732 am EST Thursday Nov 27 2014

Just updated the forecast grids with the latest model and
observational data to establish new trends in temperatures and
evolution of snow shower activity this morning. The prefirst period
that was included with the 4 am package has been removed. Snowfall
accumulations this morning will vary from a dusting to a couple of
tenths of an inch. The snow is expected to mix with and perhaps
change over to rain by this afternoon. The rain and snow should be
out of the area by late this afternoon. The new zones and hazardous
weather outlook products have been sent.


Short term...(today through friday)
issued at 308 am EST Thursday Nov 27 2014

The models were in pretty good agreement with the timing of
precipitation evolution early this morning...and with the overall
areal extent of the precipitation. A mix of rain and snow showers will
continue through late this morning before changing over to all rain
by this afternoon. Based on the latest model data...the precipitation
should be exiting eastern Kentucky late this afternoon. Extensive low
level cloud cover will persist across the area through at least 0z
this evening before finally pushing off to our east. Colder air will
filter into the region today as well...behind the departing clipper
system that is currently bringing rain and snow to the area. The cold
air intrusion...combined with the cloud cover...will keep
temperatures from rising beyond the upper 30s for most locations
today. Tonights lows will be quite cold as well...with readings
dipping into the low to middle 20s across the area. Friday will not be a
whole lot the cold air becomes further entrenched across
the area beneath a large dome of Canadian high pressure. Highs on
Friday are only expected to rise into the upper 30s and lower 40s.
Eastern Kentucky will have dry weather on Friday with partly cloudy
skies and light winds.

Long term...(friday night through wednesday)
issued at 308 am EST Thursday Nov 27 2014

Confidence is decent through the weekend...but still significant
differences on timing around a cold front early next week. High
pressure will bring fair conditions through Friday night with a
chilly night anticipated as lows dip well into the 20s and perhaps
cold enough in some of the colder valleys to see some upper teens. A
warm front will push north across the area on Saturday...with only
some middle to high clouds expected. However...this will start our
warm up this weekend as highs recover into the 50s by the afternoon.
In the wake of the warm front...models have been insistent on strong
lower level isentropic ascent developing across the Ohio River
valley. This will likely yield increasing clouds. By Saturday night
and Sunday...enough moisture may get advected northward to support
some drizzle or very light rain. Moisture is very shallow with very
little if any ice in the clouds...thus...planning to go with more of
a chance of drizzle across our northern zones through Sunday. By
Sunday night...a cold front will move into the Ohio River valley. As
mentioned above the timing is all over the place with this
front...but I would tend to prefer the slower European model (ecmwf) solution as of
right now as it has been more consistent. Regardless...plan to bring
probability of precipitation southward into the area late Sunday night through the day
Monday and into Monday night. The best bet right now for rain would
be on Monday as this seems to be the best overlap between models.
Thus...plan to go with high chance to likely probability of precipitation. While some
precipitation may linger into Monday night...models are all over the
place beyond this period...but have generally gone towards a drier
forecast as we head into midweek. Regardless...confidence beyond
Monday is very low. Outside of Friday night...temperatures will
remain above normal through the period.


Aviation...(for the 12z tafs through 12z Friday morning)
issued at 625 am EST Thursday Nov 27 2014

Scattered to numerous will affect the taf sites from time to time
early this morning. Conditions in the snow showers will vary from MVFR
to LIFR early today depending on the intensity of the snow at any
given location. The snow should mix with and change over to rain
around 13z today. Precipitation should be exiting the area by late
this afternoon.


Jkl watches/warnings/advisories...


short term...Arkansas
long term...kas

National Weather Service Glossary of Abbreviations