Area Forecast Discussion
Issued by NWS Louisville, KY
FXUS63 KLMK 280719
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOUISVILLE KY
319 AM EDT Thu Aug 28 2014
.SHORT TERM (Now through Friday)...
Issued at 245 AM EDT Thu Aug 28 2014
Typical summertime conditions are expected through the short term
period. Aloft the region will remain on the northwestern side of a
500 mb ridge through Friday. At the surface a weak front will
continue to slowly sink southward towards the KY/TN border this
morning and eventually stall out along or just south of this border.
This front will then begin to lift back northward as a warm front
late tonight through Friday.
We will start out with some patchy fog this morning, particularly in
normall fog prone locations and in areas that saw rain yesterday
afternoon and evening. This will dissipate shortly after sunrise.
With the moist and unstable airmass remaining in place isolated to
widely scattered storms are expected to develop once again this
afternoon. These storms look to fire near the front, so the best
chance will be across southern and western portions of the forecast
area. A few stronger storms could be possible with strong winds
being the main threat, similar to yesterday. Any storms will
dissipate near sunset. Friday will again see afternoon storm
development. However, the main area of concern for Friday will be
southern Indiana and north central KY along the warm front.
Temperatures will remain around or just above seasonal normals.
Highs will be in the upper 80s to lower 90s with lows mainly in the
upper 60s to lower 70s. The Bluegrass region may be just a bit
cooler tonight in the mid 60s as slightly lower dewpoint air filters
in behind the front.
.LONG TERM (Friday Night through Wednesday)...
Issued at 315 AM EDT Thu Aug 28 2014
High pressure along the U.S. east coast will combine with increasing
southwesterly winds aloft to bring us back to a period of above
normal rain chances, perhaps bringing us close to all-time record
total rainfall for the month of August at our climate sites. KBWG,
currently at fourth all-time August, needs another 1.24" to reach
that level, whereas KLEX, currently third, would need 1.98". KSDF is
farther back in the list, currently in 8th. A little less than an
inch will get them in the Top 5. A trough to our west will serve as
the focus for storms during the day Saturday. Will have a little
higher chances west of I-65.
Small scale disturbances moving through the southwest flow will
determine how widespread the coverage is beyond that period, from
Saturday night through Sunday night. Have gone into the likely range
based on precipitable water values and the likelihood of these
disturbances along the front. Temperatures should be well above
normal Saturday, with continued muggy conditions. Sunday looks to be
a little cooler with the better rain chances.
As we start the new work week, a more focused upper trough will move
in from the Central Plains. It may stay far enough away during the
day Monday to keep us more with scattered airmass thunderstorms that
day. By Tuesday the 12Z Euro had the front stalling east to west
across our region, which would mean trouble for possible flooding
concerns. The new Euro looks fairly similar. The new GFS stalled the
front just to our north for Tuesday, whereas the GEM pushes the
front to the south. Certainly something to watch given our
antecedent rainfalls for August.
For temperatures the rest of the period, will keep them above
normal, but trend back some for midweek, owing to the chance the
front could be stalled over the region keeping readings down.
.AVIATION (06Z TAF Update)...
Issued at 1250 AM EDT Thu Aug 28 2014
A weak front will continue to sink south overnight. Winds will be
light and variable to calm overnight at all TAF sites. With plenty
of low level moisture, light fog is expected to form. Will keep SDF
in the MVFR range. LEX and BWG may drop to IFR for a period towards
daybreak, so will keep a TEMPO group in for both of these sites to
account for this. Fog will dissipate an hour or two after sunrise.
Mainly VFR conditions are expected through the rest of the day. Cu
will develop late morning into the afternoon. Isolated
showers/storms are expected to develop across south central KY this
afternoon. However, confidence is low for them affecting BWG, so
will keep mention of precip out of the TAF at this time.