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Area forecast discussion 
National Weather Service Jackson Kentucky
406 PM EDT Thursday Apr 24 2014

Short term...(this evening through Friday night)
issued at 406 PM EDT Thursday Apr 24 2014

Low pressure over the middle Mississippi Valley at middle afternoon will
deepen as it moves east-northeast north of the Ohio River. It will pull Gulf of
Mexico moisture northward as it approaches...with a band of showers
and scattered thunderstorms developing as the warmer and more humid
air arrives aloft. This band of precipitation will be exiting to the east
on Friday morning. There is some discrepancy in the models concerning
timing of this precipitation...and a model compromise was used. Variation in
the timing will have an impact on the pop for Friday...and some
adjustment may be necessary. Scattered showers may linger behind the
initial round...but they will come to an end after cold frontal
passage during the day.

A ridge of high pressure will build in from the west behind the
system late Friday...bringing decreasing clouds and dry weather which
will last through Friday night.

Long term...(saturday through thursday)
issued at 351 PM EDT Thursday Apr 24 2014

Period will start off with an amplified ridging pattern
aloft...moving eastward into the Ohio River valley region as a
closed low strengthens over the Western Plains through Sunday...and
another closed low gains strength off the New England coast. As much
of Kentucky remains in this ridging pattern through the weekend...expect
winds to generally remain out of the south and warm moist air to be
advected in. This will mean above normal temperatures for the
weekend...with afternoon highs in the upper 70s to around 80 for
both Saturday and Sunday. By Monday...the closed low over the plains
will have moved eastward into the Central Plains...where it will
become somewhat more stationary and broaden. At the surface...a low
pressure system will be Colorado-located with the upper level low...over
the Central Plains Sunday into Sunday night. The associated warm
front will find itself across Kentucky Saturday and Sunday...also
supporting the enhanced temperatures. By Monday afternoon the low
will begin slowly moving eastward...with the cold front reaching Kentucky
by Monday afternoon...stalling...and then progressing across the
eastern portion of the state during the day Tuesday.

Based on the latest GFS soundings...moisture will puncture the area
in the form of high clouds Saturday night and Sunday. Dry air will
still be abundant...however...in the low levels. Moisture will then
work its way in ahead of the cold front during the day Monday.
Unfortunately...the timing and extent of precipitation is still somewhat
uncertain as the overall agreement of the models begins to
deteriorate from this point forward. With downslope flow expected
through Monday night...agree with previous forecast that this will
hamper some of our chances for widespread precipitation early on. But
should see some good chances of forward progression and widespread
coverage by late Monday and through the day Tuesday. Generally left
the 12 hour probability of precipitation up to the allblend based on uncertainty in the
model agreement...though matched up fairly well with surrounding
offices. Based on the lows trajectory through /or near to/ the state
of Kentucky...we could be in line to see some wrap around moisture and
continued probability of precipitation through Tuesday night as well.

Colder temperatures will filter in from the north with temperatures
dropping back down into the lower 70s for Tuesday afternoon. The
upper level low...and surface low...will then begin to rotate across
the east central Continental U.S....with several shortwaves developing and
rotating within the low...but making no eastward progression. If
this holds true...we can expect a very wet end of the forecast
period...with only brief breaks in precipitation from Tuesday night on. As
was stated before...the timing and set up of these shortwaves will
be what drives our precipitation coverage...so will continue to use a
consensus of the models this far out. Either way...expect temperatures to
continue cooling...falling well below normal by Wednesday and
Thursday. Cooling temperatures and loss of instability by Wednesday
should be enough to cut off any further thunderstorm threats for the
end of the forecast period.

&&

Aviation...(for the 18z tafs through 18z Friday afternoon)
issued at 233 PM EDT Thursday Apr 24 2014

VFR will persist until late tonight. After about 08z a band of
showers and scattered thunderstorms will move into the region from
the west...reaching the eastern tip of Kentucky by around 12z. A reduction
to mostly MVFR and areas of IFR is expected with the area of precipitation.
The precipitation will start to diminish from west to east after about
10z...although a few showers will linger into the day. Winds will be
fairly light until near the end of the period...when passage of a
cold front will bring an increase in wind...with gusts from the west
starting to top 20 kts.



&&

Jkl watches/warnings/advisories...
none.
&&

$$

Short term...hal
long term...geogerian
aviation...hal