Area Forecast Discussion
Issued by NWS Louisville, KY
FXUS63 KLMK 270510
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOUISVILLE KY
110 AM EDT Mon Apr 27 2015
...Updated Aviation Discussion...
Updated 840 PM EDT Sun Apr 26 2015
Still have a steady north wind for most stations this hour, and that
has helped to slow the fall of temperatures with loss of daylight.
Still think we will drop into the upper 30s for our cold spots over
the northern half of the forecast area. Winds should go fairly light
after midnight, and this may allow for some patchy frost. Have
updated the forecast to handle the locations with the best chance
for this frost.
.SHORT TERM (Now through Monday Night)...
Issued at 253 PM EDT Sun Apr 26 2015
Weather for the short term period will be dry but cool with
temperatures below normal for this time of year. Aloft a large
trough will slowly shift eastward across the eastern CONUS. At the
surface high pressure will be ridging in from the north.
Clouds across southern KY should continue to clear this afternoon.
Mostly clear skies are expected overnight. Some clouds may develop
across the northern Bluegrass tomorrow as a wave moves through the
flow aloft. These should clear tomorrow night. Lows tonight and
tomorrow night will be in the lower to mid 40s with a few sheltered
locations dropping into the upper 30s. Highs Monday will be in the
lower to mid 60s.
.LONG TERM (Tuesday through Sunday)...
Issued at 250 PM EDT Sun Apr 26 2015
Synoptic pattern by midweek is expected to feature a lingering
trough across the eastern CONUS while a split flow lies from the
central Plains. At the surface, weak high pressure to our north will
keep a drier and seasonably cool air mass in place. By late Tuesday
into Wednesday, a southern stream system is poised to track along
the Gulf coast states and the main forecast concern is how far north
precipitation spreads into the forecast area.
The 26.12z GFS/ECMWF are in similar agreement showing precipitation
spreading as far north as the Ohio River Wednesday afternoon into
early Thursday morning. The GEM solution is further south, confining
precipitation along/south of the KY border. Given the trends,
introduced slight chances of rain showers for the southern 1/3 to
1/2 of the forecast area Wednesday into Thursday morning. This
system isn`t overly moist as PWATs remain 1 inch or less.
Following this system, the forecast by the end of the upcoming work
week is looking very pleasant as upper level ridging moves over the
lower Ohio Valley with high pressure at the surface. This will allow
a slow but steady moderation in temperatures. Plan on highs to range
in the upper 60s to near 70 Thursday/Friday, low to mid 70s Saturday
and upper 70s on Sunday. Morning lows in the upper 40s to 50s. Sunny
to mostly sunny skies look to prevail each day.
.AVIATION (06Z TAF Update)...
Updated at 105 AM EDT Mon Apr 27 2015
Modest northerly gradient will persist as high pressure builds from
the Upper Midwest. Light winds will pick up slightly with daytime
mixing but will remain less than 10 kt. VFR conditions expected with
only high-based diurnal cu.