Area Forecast Discussion
Issued by NWS Louisville, KY
FXUS63 KLMK 140651
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOUISVILLE KY
251 AM EDT FRI JUN 14 2013
.SHORT TERM (Today through Saturday)...
Issued at 249 AM EDT Fri Jun 14 2013
High pressure sliding from Ontario to the Carolinas will keep our
weather quiet during the short term.
Starting things off, surface analysis early this morning shows dew
point depressions low enough in the Lake Cumberland/Dale Hollow
areas to include a few hours of patchy fog in that region around
dawn. Otherwise, we`ll see sunny skies this morning and partly
cloudy skies this afternoon as some fair weather cumulus develop.
High temperatures today will be a few degrees below normal around 80
Tonight will be clear with light breezes and lows around 60.
On Saturday we`ll start to see some increase in mid and upper
cloudiness but it will still be a mostly sunny morning and partly
cloudy afternoon at worst. There is a small possibility that a few
showers or thunderstorms may approach our southern Indiana counties
by late afternoon ahead of an approaching upper trof, but for now
will hold them off until evening. High temperatures Saturday will be
in the lower and middle 80s.
.LONG TERM (Saturday Night - Thursday)...
Issued at 251 AM EDT Fri Jun 14 2013
Upper air pattern late Saturday will feature a deep trough moving
off the New England coast, a nearly stationary trough off the
Pacific Northwest coast, and an occluded closed 500mb low north of
North Dakota. By Monday, this occluded feature will eventually move
east and become absorbed into a more broad cyclonic gyre located
east of Hudson`s Bay. A zonal, west to east 500mb flow will set up
over the Ohio Valley by Sunday, continuing through late Monday.
More humid air will move into southern Illinois and Indiana late
Saturday as southwesterly flow begins to develop on the west side of
departing Canadian high pressure, forecast to have moved over the
Sunday through early Tuesday will become humid, with variable
cloudiness and good chances for episodic convection. Initially, on
Sunday, feel that the best moisture will reside over southern
Indiana and Illinois, and correspondingly have better chances of
convection there. In addition, our northern counties will lie within
slightly better 500mb westerly flow, and closer to a stationary
east-west trough located just south of the Great Lakes.
As dewpoints rise towards the mid to upper 60s by Sunday, overnight
lows will become warm, falling only into the upper 60s or around 70
from Sunday through Tuesday morning. Highs will range in the mid
The ECMWF and the GFS are both focusing on a shallow shortwave,
forecast to move across the Commonwealth late Monday. Moisture will
pool ahead of this feature, leading to widespread cloudiness and
likely convection arriving as early as morning and continuing
possibly through the evening. With the slow movement of this feature
and PWATs rising to over 1.5 inches widespread substantial rains are
possible Monday afternoon and evening.
A weak frontal boundary will push south into Tennessee by Tuesday.
High pressure over the Great Lakes will switch our winds to the
north and bring drier air south of the Ohio River by Tuesday
afternoon. Rain chances will decrease from north to south Tuesday.
Tuesday evening through Thursday will be mostly clear and dry with
highs in the 80s with comfortable nights in the mid 60s.
.AVIATION (06Z TAF Update)...
Issued at 111 AM EDT Fri Jun 14 2013
High pressure moving from Ontario to Ohio will keep our weather
quiet. Skies will be clear this morning with light winds. Fair
weather cu can be expected during the daylight hours, with continued
northerly breezes. Then, tonight we`ll have clear skies once again
with light winds.