Area Forecast Discussion
Issued by NWS Louisville, KY
FXUS63 KLMK 291100
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOUISVILLE KY
700 AM EDT Tue Jul 29 2014
...Updated Aviation Discussion...
.SHORT TERM (Now through Wednesday)...
Issued at 300 AM EDT Tue Jul 29 2014
We`ll continue to watch temps drop early this morning with expected
lows approaching records. Here are some of the record lows for July
Bowling Green: 52, 1925 57
Frankfort: 52, 2013 54
Louisville: 58, 1928* 57
Lexington: 54, 2013 56
The rest of the day will be mostly to partly sunny with sfc high
pressure over the region and upper troughing aloft. The core of
coldest air associated with this trough will drop south into our CWA
today resulting in high temps only reaching the mid to upper 70s.
Upper level energy in the base of the trough may spark isolated
sprinkles this afternoon, but did not feel confident enough to
include this in the forecast. Here are record cold max temps for
Bowling Green: 75, 2000 78
Frankfort: 74, 1994* 75
Louisville: 71, 1981 78
Lexington: 70, 1972 76
(* and previous years)
Tonight will once again be cool with mainly clear to partly cloudy
skies. Sfc ridging will become stronger over our region resulting
in light or calm winds and good rad cooling. Lows will once again
drop into the mid to upper 50s. Here is a look at some of the
record lows for July 30th:
Bowling Green: 53, 1965 56
Frankfort: 50, 1965 56
Louisville: 55, 1965 61
Lexington: 51, 1965 58
In addition to cool temps, patchy fog may develop late tonight into
Wed morning. For now, kept fog confined to valley locations but an
expansion in area may be needed in coming forecasts. Don`t think
fog will be too thick or widespread though at this time.
Wednesday temps will rebound back into the upper 70s and lower 80s
across the region for highs. More upper level disturbances within
the broad upper trough over the Midwest will provide light precip
chances to our north but think that our area will remain largely dry.
.LONG TERM (Wednesday Night through Monday)...
Issued at 300 AM EDT Tue Jul 29 2014
An amplified pattern with troughing centered near the Great Lakes
will remain in place through much of the extended. The core of the
500mb trough will remain in place near St James` Bay through Friday,
before being pushed east by increasing flow across the Canadian
Prairies. Even when this occurs, residual troughing will continue
over the Lower Ohio Valley through early Monday.
Despite the presence of troughing aloft, surface pressure gradients
will remain quite light for practically the entire weekend, with
nearly calm winds at night and light afternoon winds that will tend
to stay from the north or northeast.
Temperatures will stay cooler than late July Climo, which averages
around 88 and 68 for the last day in July. Gradually, temperatures
will slowly moderate from Thursday through Sunday, with average
highs rising from the lower to mid 80s, to the mid to upper 80s by
Despite troughing and generally cool 500mb temperatures aloft, deep
moisture will remain limited to the near Gulf regions and diurnal
shower activity will remain limited. Have maintained current
forecast of isolated to scattered afternoon and evening
thunderstorms for Friday and Saturday afternoons, when the upper
trough axis will lie right over the Commonwealth.
.AVIATION (12Z TAF Update)...
Issued at 645 AM EDT Tue Jul 29 2014
High pressure building in from the Plains to the Ohio Valley will
give us light northwest breezes and VFR conditions through the TAF
period. Dry air advection should be the limiting factor for any fog
chances at the terminals this morning. However, with stronger sfc
ridging progged to enter the area tomorrow morning, the TAF sites
might be a little more susceptible to light br.