Alert archive / Kentucky / Frost Advisories in 2021

Frost Advisory 5, NWS Louisville, KY

April 30, 202128 counties in Kentucky; Jefferson County, Indiana

NWS Louisville, KY issued this frost advisory at Apr 30, 2021, 2:28 AM CDT for 28 counties in Kentucky; Jefferson County, Indiana. It took effect at May 1, 2021, 1:00 AM CDT. It was in force for 6 hr.

The area

The counties it named.

The facts

Issued
Apr 30, 2021, 2:28 AM CDT (07:28 UTC)
In effect from
May 1, 2021, 1:00 AM CDT
Expired
May 1, 2021, 7:25 AM CDT
In force
6 hr
Issued by
NWS Louisville, KY
All 29 counties

Jefferson County, IN, Adair County, KY, Anderson County, KY, Bourbon County, KY, Boyle County, KY, Casey County, KY, Clark County, KY, Clinton County, KY, Cumberland County, KY, Fayette County, KY, Franklin County, KY, Garrard County, KY, Harrison County, KY, Henry County, KY, Jessamine County, KY, Lincoln County, KY, Madison County, KY, Marion County, KY, Mercer County, KY, Nelson County, KY, Nicholas County, KY, Russell County, KY, Scott County, KY, Shelby County, KY, Spencer County, KY, Taylor County, KY, Trimble County, KY, Washington County, KY, Woodford County, KY

The radar

The Louisville radar (KLVX), 94 km from the middle of the area, began a volume at 07:28 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

The nearest sounding before it

Cncnati-Daytn, OH (KILN), launched 00:00Z, 7.5 hours before the alert went out and 201 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-pSkew-T log-p diagram, Cncnati-Daytn, OH at 00:00Z on 2021-04-30Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Cncnati-Daytn, OH at 00:00Z on 2021-04-30The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -159 square meters per square second.1939587897117Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
728 m above ground
0-6 km bulk shear
72 kt
0-1 km storm-relative helicity
-159 m²/s²
0-3 km storm-relative helicity
-122 m²/s²
Significant tornado parameter
0.0
Supercell composite
-0.1

Open this sounding in Storm Lab

The text

As transmitted.

090 
WWUS73 KLMK 300728
NPWLMK

URGENT - WEATHER MESSAGE
National Weather Service Louisville KY
328 AM EDT Fri Apr 30 2021

KYZ035>037-039>043-047>049-055>057-066-067-302000-
/O.NEW.KLMK.FR.Y.0005.210501T0600Z-210501T1300Z/
Franklin-Scott-Harrison-Anderson-Woodford-Fayette-Bourbon-
Nicholas-Mercer-Jessamine-Clark-Boyle-Garrard-Madison-Casey-
Lincoln-
Including the cities of Frankfort, Georgetown, Cynthiana, 
Lawrenceburg, Versailles, Lexington, Paris, Carlisle, 
Harrodsburg, Nicholasville, Winchester, Danville, Lancaster, 
Richmond, Liberty, and Stanford
328 AM EDT Fri Apr 30 2021

...FROST ADVISORY IN EFFECT FROM 2 AM TO 9 AM EDT SATURDAY...

The National Weather Service in Louisville has issued a Frost
Advisory, which is in effect from 2 AM to 9 AM EDT Saturday. 

* TEMPERATURE...Lows Saturday morning will be in the mid 30s, with
  lower readings possible in deeper valleys and sheltered rural
  locations. 

* IMPACTS...Vegetation sensitive to frost may be damaged or killed
  if left uncovered. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Frost Advisory means that widespread frost is expected.
Sensitive outdoor plants may be killed if left uncovered.

&&

$$

JML
2 follow-up statements
969 
WWUS73 KLMK 301859
NPWLMK

URGENT - WEATHER MESSAGE
National Weather Service Louisville KY
259 PM EDT Fri Apr 30 2021

INZ079-KYZ032>034-038-045-046-054-065-077-078-081-082-011300-
/O.EXA.KLMK.FR.Y.0005.210501T0600Z-210501T1300Z/
Jefferson-Trimble-Henry-Shelby-Spencer-Nelson-Washington-Marion-
Taylor-Adair-Russell-Cumberland-Clinton-
Including the cities of Madison, Bedford, Milton, New Castle, 
Shelbyville, Taylorsville, Bardstown, Springfield, Lebanon, 
Campbellsville, Columbia, Jamestown, Burkesville, and Albany
259 PM EDT Fri Apr 30 2021 /159 PM CDT Fri Apr 30 2021/

...FROST ADVISORY IN EFFECT FROM 2 AM EDT /1 AM CDT/ TO 9 AM EDT
/8 AM CDT/ SATURDAY...

The National Weather Service in Louisville has issued a Frost
Advisory, which is in effect from 2 AM EDT /1 AM CDT/ to 9 AM EDT
/8 AM CDT/ Saturday. 

* TEMPERATURE...Lows Saturday morning will be in the mid 30s, 
  with lower readings possible in deeper valleys and sheltered 
  rural locations. 

* IMPACTS...Vegetation sensitive to frost may be damaged or 
  killed if left uncovered. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Frost Advisory means that widespread frost is expected.
Sensitive outdoor plants may be killed if left uncovered.

&&

$$

KYZ035>037-039>043-047>049-055>057-066-067-011300-
/O.CON.KLMK.FR.Y.0005.210501T0600Z-210501T1300Z/
Franklin-Scott-Harrison-Anderson-Woodford-Fayette-Bourbon-
Nicholas-Mercer-Jessamine-Clark-Boyle-Garrard-Madison-Casey-
Lincoln-
Including the cities of Frankfort, Georgetown, Cynthiana, 
Lawrenceburg, Versailles, Lexington, Paris, Carlisle, 
Harrodsburg, Nicholasville, Winchester, Danville, Lancaster, 
Richmond, Liberty, and Stanford
259 PM EDT Fri Apr 30 2021

...FROST ADVISORY REMAINS IN EFFECT FROM 2 AM TO 9 AM EDT
SATURDAY...

* TEMPERATURE...Lows Saturday morning will be in the mid 30s, 
  with lower readings possible in deeper valleys and sheltered 
  rural locations. 

* IMPACTS...Vegetation sensitive to frost may be damaged or 
  killed if left uncovered. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Frost Advisory means that widespread frost is expected.
Sensitive outdoor plants may be killed if left uncovered.

&&

$$

CJP
176 
WWUS73 KLMK 011225
NPWLMK

URGENT - WEATHER MESSAGE
National Weather Service Louisville KY
825 AM EDT Sat May 1 2021

...FROST ADVISORY IS CANCELLED...

INZ079-KYZ032>043-045>049-054>057-065>067-077-078-081-082-011330-
/O.CAN.KLMK.FR.Y.0005.000000T0000Z-210501T1300Z/
Jefferson-Trimble-Henry-Shelby-Franklin-Scott-Harrison-Spencer-
Anderson-Woodford-Fayette-Bourbon-Nicholas-Nelson-Washington-
Mercer-Jessamine-Clark-Marion-Boyle-Garrard-Madison-Taylor-Casey-
Lincoln-Adair-Russell-Cumberland-Clinton-
Including the cities of Madison, Bedford, Milton, New Castle, 
Shelbyville, Frankfort, Georgetown, Cynthiana, Taylorsville, 
Lawrenceburg, Versailles, Lexington, Paris, Carlisle, Bardstown, 
Springfield, Harrodsburg, Nicholasville, Winchester, Lebanon, 
Danville, Lancaster, Richmond, Campbellsville, Liberty, Stanford,
Columbia, Jamestown, Burkesville, and Albany
825 AM EDT Sat May 1 2021 /725 AM CDT Sat May 1 2021/

...FROST ADVISORY IS CANCELLED...

The National Weather Service in Louisville has cancelled the
Frost Advisory. 

Temperatures have warmed into the upper 30s to mid 40s, so the
Frost Advisory has been cancelled. 

$$

EBW

The office that day

Everything else NWS Louisville, KY issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 29, 9:35 PM CDTRiver Flood WarningLMKOhio27 hr
Apr 29, 8:52 PM CDTRiver Flood AdvisoryLMKJefferson, Scott10 hr

Nearby

Frost Advisories in Kentucky, 2021Frost Advisories in Indiana, 2021Every frost advisory in 2021

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.