Scientific Forecaster Discussion

Return to Local Conditions & Forecast

Without Abbreviations
With Abbreviations

fxus63 kjkl 252352 

Area forecast discussion
National Weather Service Jackson Kentucky
752 PM EDT Tue Apr 25 2017

issued at 752 PM EDT Tuesday Apr 25 2017

An eroding and eastward moving stratocumulus deck will give way to
some approaching mid-high clouds from the west this evening and
tonight. Patchy fog therefore continues to be a good bet given the
moist ground and light winds accompanying this clearing. The
approaching mid and high clouds may be enough to keep this from
becoming too widespread or dense, but valley locales certainly
look to see some low visibilities tonight into Wednesday morning.


Short term...(this evening through Wednesday night)
issued at 326 PM EDT Tuesday Apr 25 2017

Surface analysis this afternoon shows a weak surface high nearby
at best and we are stuck between two low pressure systems. The
biggest issue today has been the stratocu and overall this seem to
be down ticking slowly this afternoon. The guidance remains
optimistic and given the higher heights think this is reasonable.
Also winds will veer around to the southeast tonight, and this should
also aid clearing the clouds with more favorable downslope flow.
The clearing will also leave the opportunity for some patchy
mostly valley fog tonight. Also some slight temperature splits in
the deeper valleys.

Wednesday day will feature height rises and warm air advection ahead of the next
front. That said, low to mid 80s are not out of the question.
Particularly if downsloping leads to a bit dryer air at the
surface. The aforementioned weakening surface front will move
east toward the region Wednesday night, with some timing
differences in the model output. Most cams would suggest at least
some showers are possible in the Lake Cumberland region by dawn,
but other guidance is a bit slower. Felt like slight to chance
pops was not out of the question given the blend.

Long term...(thursday through tuesday)
issued at 326 PM EDT Tuesday Apr 25 2017

The extended portion of the forecast begins on Thursday with an
active and somewhat amplified period. During this time, the models
are in fair agreement as a trough and surface cold front advances
east but it being sheared out against Stout blocking just off the
East Coast. The surface low will lift far to the north into the
Great Lakes as the front weakens and pushes into eastern Kentucky.
Nevertheless, minimal instability and plenty of shear will produce
some possibilities of damaging winds associated with a line or at
least some gusty winds. A possible scenario could be the best
convection farther to the north into Ohio and PA with the low. Heading
into the weekend, a warm front will develop and lift north by Friday
afternoon providing another period of showers and thunderstorms. The
front lifts north of the County Warning Area by Saturday putting the area in the
warm sector. This will provide a strongly capped region with a few
showers possible through Saturday afternoon. By Sunday morning, the
cold front will push into Kentucky and then eastern Kentucky by the
afternoon. This feature seems to be a bit more dynamic than the
previous system but it is still unclear if there is any severe
potential at this time. Temperatures have been quite warm and dew
points look to be in the 60s according to the super blend so this
scenario will be monitored for the severe potential.

The overall values put in place by the blend seemed reasonable with
the models so little changes were made. The one certainty through
the extended and for the month of April for that matter is the
abnormally warm temperatures. With the warm temps so far and the
forecast through the end of the month, April will likely go down as
one of the warmest months. The forecast suggests that the record
highs at Jackson for the 28th and 29th stand a chance to be


Aviation...(for the 00z tafs through 00z Wednesday evening)
issued at 752 PM EDT Tuesday Apr 25 2017

Low clouds continue to erode and move east this evening. Have
opted to leave MVFR fog in the forecast for sme/loz/sym given the
earlier clearing, despite some mid-high clouds streaming in from
the west. Jkl may see some visibility/ceiling degradation early
Wednesday morning as valley fog lifts, while sjs looks to stand
the best chance of remaining VFR with the later arrival of
clearing skies. Light winds overnight and moist soils will further
promote the potential for fog, before VFR conditions return
early-mid Wednesday morning through the evening. As winds veer
south/southwesterly through the afternoon, speeds will increase to
5-10 knots.


Jkl watches/warnings/advisories...


National Weather Service Glossary of Abbreviations