Area Forecast Discussion
Issued by NWS Louisville, KY
FXUS63 KLMK 141048
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOUISVILLE KY
648 AM EDT TUE MAY 14 2013
...Updated Aviation Discussion...
.Short Term (Today - Wednesday)...
Issued at 300 AM EDT Tue May 14 2013
Surface high pressure will continue to shift south and east today
through Wednesday as a low moves from Manitoba to Quebec, Canada
during the short-term period. Return flow will increase, with
southwest winds gusting into the 20-25 mph range each afternoon
bringing very warm air into the region. Some mid level cloudiness
this morning will give way to plenty of sunshine this afternoon,
with another sunny day anticipated Wednesday. Combine the warm air
advection with mostly sunny conditions and high temperatures should
reach the upper 70s in our east to lower 80s across our west today,
and CWA-wide low to mid 80s for Wednesday afternoon. Lows tonight
will be much warmer than what we have experienced the last few days,
with temperatures in the lower 60s on tap for most locations.
A frontal boundary trailing the low crossing Canada will slide south
into central Illinois, Indiana, and Ohio late in the day Wednesday.
Any showers or thunderstorms will remain confined to that boundary,
which means we will stay dry today through Wednesday. However, as
the front stalls just north of our forecast area, rain chances will
increase. See the long term section below for more details.
.Long Term (Wednesday Night - Monday)...
Issued at 300 AM EDT Tue May 14 2013
Models are still depicting a very unsettled pattern in the long term
with several hard to time features with an open Gulf providing
plenty of moisture. Will try to go with a 0Z model consensus and
previous forecast blend to better define some timing issues but keep
forecast consistency. This will result in 20-50% POPs every day in
the long term period and overall a lower confidence forecast
although will try to note the best and least chances for
showers/t-storms in this discussion.
A sfc frontal boundary will be positioned to our north Wed
night-Thurs night with an upper level trough passing through on
Thurs bringing a better chance for scattered convection to occur
over our area. Therefore, bumped POPs up to 40-50% during this time
The front then looks to move north for Fri with only some diurnal
based convection possible. Temps Thurs/Fri look to be in the upper
70s/lower 80s for highs with lows in the 60s.
As we move into the weekend, upper level ridging will increase
across the Midwest with another upper level disturbance progged to
move through the area on Sat. So we`ll see high temps rise into the
lower 80s for highs area wide with isld-scattered showers/t-storms
possible Sat/Sun especially during the afternoon/evening hours
during peak heating.
By the beginning of next week, a potent upper level trough and cold
front will push eastward out of the Plains states bringing the best
chance of showers/t-storms to the entire area by Mon night-Tues
night as the front moves through the area. Although timing will
more than likely need to be adjusted with this fropa at the end of
the long term period, we`ll likely see the most widespread and
strongest storms with this upper trough and cold front.
Temperatures behind the front will cool off into the 60s for highs
for the middle of next week.
.Aviation (12Z TAF Issuance)...
Issued at 648 AM EDT Tue May 14 2013
High pressure in control will provide VFR conditions through the TAF
period, with just a scattered mid-level cloud deck through the
morning hours. With the surface high shifting southeast through the
TAF period, south-southwest return flow will increase. Mixing and a
tightening pressure gradient by this afternoon will allow gusts over
20 knots. Wind gusts will subside shortly before sunset, but
sustained speeds of 7-12 knots will remain overnight.