Flash Flood Warning 32, NWS Louisville, KY

Area Forecast Discussion
National Weather Service Louisville KY
652 AM EDT Mon Jun 29 2020

...Updated Aviation Discussion...

.Short Term...(Today and tonight)
Issued at 234 AM EDT Mon Jun 29 2020

...Flash Flood Threat Continues Today...

A narrow swath of precipitation has developed and persisted for the
last few hours in response to weak speed convergence in the 900mb-
800mb layer. Latest SPC mesoanalysis progs +1,000 J/KG MUCAPE across
most of the forecast area, which has helped to contribute to
thunderstorm development within the precipitation axis. Storm
motions are nearly parallel to this convergence zone, and the
atmosphere is very conducive for heavy downpours in thunderstorm
activity given the high PWATs, so there is some concern that a flood
threat may develop here shortly this morning. Latest suite of high-
res models generally capture the development of this precipitation
axis; however, they vary in its intensity and overall duration. The
last part of this equation (duration) will have the biggest impact
on rainfall amounts and potential flood severity, as the convergence
zone won't move much in the next 6 to 9 hours, and most shower/storm
activity will train over the same areas. Best guess at this time is
activity will slowly taper down by mid to late morning as 900mb-
800mb convergence weakens, though it could continue into the early
afternoon if 900mb-800mb speed convergence persists. If there's any
silver lining to all of this, it appears that all of this activity
should occur outside of the hardest hit areas from yesterday and
within the current flash flood watch.

Additional shower and storm activity may fire off this afternoon
across western portions of the CWA in response to a weak vort max
embedded within mid/upper level flow. This activity would
potentially occur over some of the hardest hit areas that received
rainfall yesterday, which have quite low 1hr/3hr FFG (1-1.5"). Given
how rain efficient this activity will be, flash flooding will be a
concern. Additionally, while deep layer shear will be marginal,
there will be some potential for isolated strong to severe storms
with gusty winds during the afternoon hours.

Shower and storm activity may continue past sunset for parts of the
region. While the current flash flood watch runs through 00z
Tuesday, it appears most activity overnight would not be training
along any defined mesoscale boundaries, so the watch may be able to
expire at its designated time.

.Long Term...(Tuesday through Sunday)
Issued at 230 AM EDT Mon Jun 29 2020

Little change in the overall thought process for unsettled weather
for much of next week. Upper level ridging continues over the top of
us as the omega-blocking pattern continues with upper level lows on
either side across the New England and the Pacific Northwest. This
pattern should persist through Friday. Weak surface boundary stalls
out across the Ohio Valley Tuesday through Thursday before surface
high pressure looks to try and build in for the weekend.

The aforementioned boundary will be the focal point of convective
activity through most of the week. At times we could see multiple
MCS move along this boundary Tuesday through Thursday. There will be
moderate instability through out the week as we remain warm and
humid. The main limiting factor to the overall severe threat is a
lack of vertical shear. With the stalled boundary helping to provide
some lift, we will see nearly daily chances for showers and
thunderstorms. These storms could produce gusty winds and torrential
rainfall. Dew point values will remain at or above 70 degrees and
PWAT values from 1.6 to 2.0" range that the threat of flash flooding
could be an issue with any storm activity.

Quick look at the holiday weekend, upper level ridging looks to
expand out of the central CONUS as high pressure at the surface
moves in from the upper Midwest for the weekend. We will remain warm
and very humid but lower precipitation chances.

&&

.Aviation...(12Z TAF Issuance)
Issued at 650 AM EDT Mon Jun 29 2020

A narrow corridor of showers and storms continued this morning
across central KY. We've seen IFR conditions at times from BWG due
to visibility and MVFR for LEX dues to CIG. With area of light rain
this morning, LEX looks to stay around MVFR through 14z due to lower
CIGS. We anticipate this activity to slowly subside during the
morning with a possible lull before the next round of rain/storms
develops around 19/20z. Confidence on where the afternoon
convection will occur remains low.

&&

.LMK WATCHES/WARNINGS/ADVISORIES...
IN...Flash Flood Watch through this evening for INZ084-089>091.

KY...Flash Flood Watch through this evening for KYZ023>030-038-
     045>047-053>057-061>067-071-073>078-081-082.

&&

Short Term...DM
Long Term...BTN
Aviation...BTN

Hazardous Weather Outlook
National Weather Service Louisville KY
250 AM EDT Mon Jun 29 2020

INZ076>079-083-092-KYZ031>037-039>043-048-049-070-072-300700-
Orange-Washington-Scott-Jefferson-Dubois-Clark-Oldham-Trimble-Henry-
Shelby-Franklin-Harrison-Anderson-Woodford-Fayette-Bourbon-Nicholas-
Jessamine-Logan-Simpson-
Including the cities of Paoli, Salem, Scottsburg, Madison, Jasper,
Jeffersonville, La Grange, Bedford, Milton, New Castle, Shelbyville,
Frankfort, Georgetown, Cynthiana, Lawrenceburg, Versailles,
Lexington, Paris, Carlisle, Nicholasville, Winchester, Russellville,
Franklin, and Providence
250 AM EDT Mon Jun 29 2020 /150 AM CDT Mon Jun 29 2020/

This hazardous weather outlook is for portions of south central
Indiana and Central Kentucky.

.DAY ONE...Today and Tonight.

Tropical air in place will combine with a slow-moving boundary in
the region to cause another wave of thunderstorms over central
Kentucky and southern Indiana. Additional thunderstorms are expected
to develop this afternoon outside of this boundary. Areas that see
repeated thunderstorms could see flash flooding.

.DAYS TWO THROUGH SEVEN...Tuesday through Sunday.

Shower and thunderstorm chances will continue into next week. Gusty
winds will be the main threats with thunderstorms, but small hail
will also be possible. Localized flash flooding will be possible in
areas where thunderstorms repeatedly occur.

.SPOTTER INFORMATION STATEMENT...

Spotters should report any instances of flooding the next couple
of days as well any stronger wind gusts or damage.

INZ084-089>091-KYZ023>030-038-045>047-053>057-061>067-071-073>078-
081-082-300700-
Crawford-Perry-Harrison-Floyd-Hancock-Breckinridge-Meade-Ohio-
Grayson-Hardin-Bullitt-Jefferson-Spencer-Nelson-Washington-Mercer-
Larue-Marion-Boyle-Garrard-Madison-Butler-Edmonson-Hart-Green-Taylor-
Casey-Lincoln-Warren-Allen-Barren-Monroe-Metcalfe-Adair-Russell-
Cumberland-Clinton-
Including the cities of English, Tell City, Corydon, New Albany,
Lewisport, Hawesville, Hardinsburg, Brandenburg, Hartford,
Leitchfield, Elizabethtown, Shepherdsville, Louisville,
Taylorsville, Bardstown, Springfield, Harrodsburg, Hodgenville,
Lebanon, Danville, Lancaster, Richmond, Morgantown, Brownsville,
Horse Cave, Greensburg, Campbellsville, Liberty, Stanford,
Bowling Green, Scottsville, Glasgow, Tompkinsville, Edmonton,
Columbia, Jamestown, Burkesville, and Albany
250 AM EDT Mon Jun 29 2020 /150 AM CDT Mon Jun 29 2020/

...FLASH FLOOD WATCH IN EFFECT THROUGH THIS EVENING...

This hazardous weather outlook is for portions of south central
Indiana and Central Kentucky.

.DAY ONE...Today and Tonight.

Tropical air in place will combine with a slow-moving boundary in
the region to cause another wave of thunderstorms over central
Kentucky and southern Indiana. Additional thunderstorms are expected
to develop this afternoon outside of this boundary. Areas that see
repeated thunderstorms could see flash flooding.

.DAYS TWO THROUGH SEVEN...Tuesday through Sunday.

Shower and thunderstorm chances will continue into next week. Gusty
winds will be the main threats with thunderstorms, but small hail
will also be possible. Localized flash flooding will be possible in
areas where thunderstorms repeatedly occur.

.SPOTTER INFORMATION STATEMENT...

Spotters should report any instances of flooding the next couple
of days as well any stronger wind gusts or damage.

DM/BTN

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE LOUISVILLE KY
601 AM EDT MON JUN 29 2020

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0600 AM     FLASH FLOOD      1 N SPRINGFIELD         37.70N 85.22W
06/29/2020                   WASHINGTON         KY   911 CALL CENTER

            MULTIPLE REPORTS OF FLOODED ROADWAYS ACROSS
            THE COUNTY. SOME INCLUDE LINCOLN PARK ROAD
            AND HIGHWAY 150 NEAR SPRINGFIELD, KENTUCKY.

&&

DM