Alert archive / Florida / Frost Advisories in 2021

Frost Advisory 3, NWS Tampa Bay, FL

January 18, 20214 counties in Florida

NWS Tampa Bay, FL issued this frost advisory at Jan 18, 2021, 4:05 PM EST for 4 counties in Florida. It took effect at Jan 19, 2021, 3:00 AM EST. It was in force for 5 hr.

The area

The counties it named.

The facts

Issued
Jan 18, 2021, 4:05 PM EST (21:05 UTC)
In effect from
Jan 19, 2021, 3:00 AM EST
Expired
Jan 19, 2021, 8:00 AM EST
In force
5 hr
Issued by
NWS Tampa Bay, FL

Counties Citrus County, FL, Hernando County, FL, Pasco County, FL, Sumter County, FL

The radar

The Tampa radar (KTBW), 100 km from the middle of the area, began a volume at 21:06 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

Tampa Bay, FL (KTBW), launched 12:00Z, 9.1 hours before the alert went out and 100 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, Tampa Bay, FL at 12:00Z on 2021-01-18Temperature 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, Tampa Bay, FL at 12:00Z on 2021-01-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -19 square meters per square second.1939587897117136156Sfc1 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
882 m above ground
0-6 km bulk shear
87 kt
0-1 km storm-relative helicity
-19 m²/s²
0-3 km storm-relative helicity
60 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

008 
WWUS72 KTBW 182105
NPWTBW

URGENT - WEATHER MESSAGE
National Weather Service Tampa Bay Ruskin FL
405 PM EST Mon Jan 18 2021

FLZ139-239-242-248-191300-
/O.CON.KTBW.FZ.W.0002.210119T0800Z-210119T1300Z/
Coastal Levy-Inland Levy-Inland Citrus-Inland Hernando-
Including the cities of Cedar Key, Yankeetown, Chiefland, 
Bronson, Williston, Inverness, Brooksville, and Spring Hill
405 PM EST Mon Jan 18 2021

...FREEZE WARNING REMAINS IN EFFECT FROM 3 AM TO 8 AM EST
TUESDAY...

* WHAT...Sub-freezing temperatures as low as 30 expected.

* WHERE...Coastal Levy, Inland Levy, Inland Citrus and Inland 
  Hernando Counties.

* WHEN...From 3 AM to 8 AM EST Tuesday.

* IMPACTS...Frost and freeze conditions will kill crops, other 
  sensitive vegetation and possibly damage unprotected outdoor 
  plumbing.


PRECAUTIONARY/PREPAREDNESS ACTIONS...

A freeze warning means widespread freezing temperatures are
expected to occur. Take steps now to protect tender plants from
the cold. Exposed outdoor water pipes may burst if not wrapped or
covered.

&&

$$

FLZ043-142-148-249-191300-
/O.NEW.KTBW.FR.Y.0003.210119T0800Z-210119T1300Z/
Sumter-Coastal Citrus-Coastal Hernando-Inland Pasco-
Including the cities of Wildwood, Lake Panasoffkee, Bushnell, 
The Villages, Crystal River, Homosassa, Hernando Beach, Bayport, 
Dade City, and Zephyrhills
405 PM EST Mon Jan 18 2021

...FROST ADVISORY IN EFFECT FROM 3 AM TO 8 AM EST TUESDAY...

* WHAT...Temperatures as low as 33 will result in frost 
  formation.

* WHERE...Sumter, Coastal Citrus, Coastal Hernando and Inland 
  Pasco Counties.

* WHEN...From 3 AM to 8 AM EST Tuesday.

* IMPACTS...Frost could kill sensitive outdoor vegetation if 
  left uncovered.


PRECAUTIONARY/PREPAREDNESS ACTIONS...

Take steps now to protect tender plants from the cold.

&&

$$

For more information from the National Weather Service visit
https://weather.gov/tampabay

The office that day

Everything else NWS Tampa Bay, FL issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jan 18, 3:39 AM ESTFreeze WarningTBWCitrus, Hernando, Levy28 hr

Nearby

Frost Advisories in Florida, 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.