Forecast Discussions mentioning any of
"ACARS" "MDCRS" "AIRCRAFT" "TAMDAR" "AMDAR" "WVSS" received at GSD on 05/28/19
Area Forecast Discussion
National Weather Service Louisville KY
848 PM EDT Mon May 27 2019
Issued at 845 PM EDT Mon May 27 2019
Fortunately much quieter weather in our neck of the woods this
evening. A cap was able to develop this afternoon, based on AMDAR
soundings and the lack of deep convection in our area. Farther
north in central Indiana, on the leading edge of those stronger
low-level winds and ahead of that cap, we have several quickly
rotating thunderstorms. Have removed any additional storm chances
from the evening forecast in an update out shortly.
.Short Term...(This evening through Tuesday)
Issued at 300 PM EDT Mon May 27 2019
The warm front is exiting our northern CWA at this hour and will
continue to push northward toward the lower Great Lakes region by
tonight. As a result, steady SSW winds have taken hold and temps
have risen to the low to mid 80s north and upper 80s south.
We have become moderately unstable in the warm and muggy warm sector
this afternoon beneath fairly steep mid level lapse rates, and the
big question is whether we can develop any additional
showers/storms. One factor that would favor isolated development of
a few showers/storms would be a steady increase in low level jetting
associated with the system over the upper Midwest. Enough isentropic
lift may occur to kick off some convection so will continue to leave
mention of isolated chances this afternoon/evening. One factor that
could inhibit initial development is a subtle inversion evident on
forecast soundings between H85-H7. This feature is expected to
increase in magnitude later this afternoon/evening so it appears our
window to develop convection will shorten with every hour. If a few
showers and storms are able to develop, then there would be a chance
for a few strong "pulse type" storms. Main threats would be
lightning, brief heavy rain, gusty winds, and perhaps some small
Otherwise, expect a mostly clear and mild overnight with lows in the
upper 60s and low 70s. This will be thanks to a steady SSW wind
mostly between 5 and 10 mph.
The H85-H7 inversion appears to strengthen on Tuesday as the upper
ridge centered to our SE takes a little better hold of the area. As
a result, we should stay dry. With mostly sunny skies and a steady
SW wind/warm advection component we should be able to warm into the
upper 80s and low 90s for highs.
.Long Term...(Tuesday night through Monday)
Issued at 315 PM EDT Mon May 27 2019
Tuesday Night - Thursday...
Tues night the upper level ridge over the region will weaken
allowing a sfc boundary to drop south into our region. This will
allow several shortwaves to pass through the Ohio Valley producing
isld-sct showers/storms late Tues night through Wednesday. Models
indicate a good amount of instability (2000-2500 k/jg CAPE) will
build ahead of storms Wed afternoon/evening. This combined with
reasonable wind profiles may be enough to produce strong to isolated
severe storms. The best focus for storms will be over southern
Indiana/northern KY closer to the weak boundary and best moisture
On Thursday, expect the main cold front and sfc low pressure to push
NE through the Ohio Valley with a weakening upper trough lagging
behind. This will result in more chances for sct showers/storms.
Wind profiles will be stronger and more favorable for organized
convection, however, instability will be in question depending on
evolution of previous convective complexes Wed night/early Thu
morning. At this point, strong storms do look possible on Thu.
Temperatures will continue to be quite warm ahead of the cold front
with highs ranging through the 80s to around 90 on Wed and Wed night
lows in the upper 60s. Thu high temps will range from the low to
mid 80s as forecast but could be warmer depending on sky
cover/precip early in the day. Both Wed/Thu look to be breezy
outside of any convective activity.
Friday - Saturday...
As the aforementioned upper trough slowly moves through the area on
Fri, isld-sct showers/storms will again be possible. Wind
fields/instability will be considerably less on Fri so not expecting
any organized svr wx threat.
Friday night through Sat night looks to be the driest period in the
long term with a break in the shortwave activity. Temps should be
in the upper 70s/lower 80s for highs.
Sunday - Monday...
Long range models differ on how quickly an upper ridge will build
back into the Ohio Valley from the west. The 12Z GFS/GFS Ensembles
suggest we could get caught in a train of MCS activity in NW flow
for the beginning of next week. However, the 12Z Euro indicates a
quick cold front passage on Sun with the upper ridge quickly
building east toward the Ohio Valley Mon/Tue.
.Aviation...(00Z TAF Issuance)
Updated at 650 PM EDT Mon May 27 2019
Expect steady SW winds mostly around 10 mph through tonight. By
Tuesday, slightly stronger SW winds will take hold along with a few
gusts in the 20-25 mph range. The only notable cloud cover will be
few-sct Cu around 3-5 k feet and some upper sky cover at times.