Alert archive / New York / Frost Advisories in 2026

Frost Advisory 6, NWS Buffalo, NY

May 21, 20264 counties in New York

NWS Buffalo, NY issued this frost advisory at May 21, 2026, 1:10 AM EDT for 4 counties in New York. It took effect at May 21, 2026, 11:00 PM EDT. It was in force for 9 hr.

The area

The counties it named.

The facts

Issued
May 21, 2026, 1:10 AM EDT (05:10 UTC)
In effect from
May 21, 2026, 11:00 PM EDT
Expired
May 22, 2026, 8:00 AM EDT
In force
9 hr
Issued by
NWS Buffalo, NY

Counties Allegany County, NY, Jefferson County, NY, Lewis County, NY, Oswego County, NY

The radar

The Ft Drum radar (KTYX), 74 km from the middle of the area, began a volume at 05:12 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

Buffalo Intl Airport, NY (KBUF), launched 00:00Z, 5.2 hours before the alert went out and 190 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, Buffalo Intl Airport, NY at 00:00Z on 2026-05-21Temperature 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°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Buffalo Intl Airport, NY at 00:00Z on 2026-05-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -102 square meters per square second.19395878Sfc1 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
1222 m above ground
0-6 km bulk shear
35 kt
0-1 km storm-relative helicity
-102 m²/s²
0-3 km storm-relative helicity
-11 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

959 
WWUS71 KBUF 210510
NPWBUF

URGENT - WEATHER MESSAGE
National Weather Service Buffalo NY
110 AM EDT Thu May 21 2026

NYZ007-008-211900-
/O.NEW.KBUF.FR.Y.0006.260522T0300Z-260522T1200Z/
Jefferson-Lewis-
Including the cities of Watertown and Lowville
110 AM EDT Thu May 21 2026

...FROST ADVISORY IN EFFECT FROM 11 PM THIS EVENING TO 8 AM EDT 
FRIDAY...

* WHAT...Temperatures in the mid 30s will result in areas of frost 
  formation.

* WHERE...Jefferson and Lewis Counties.

* WHEN...From 11 PM this evening to 8 AM EDT Friday.

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

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Take steps now to protect tender plants from the cold.

&&

$$

HSK
3 follow-up statements
294 
WWUS71 KBUF 211630
NPWBUF

URGENT - WEATHER MESSAGE
National Weather Service Buffalo NY
1230 PM EDT Thu May 21 2026

NYZ006-021-220430-
/O.EXA.KBUF.FR.Y.0006.260522T0300Z-260522T1200Z/
Oswego-Allegany-
Including the cities of Oswego and Wellsville
1230 PM EDT Thu May 21 2026

...FROST ADVISORY IN EFFECT FROM 11 PM THIS EVENING TO 8 AM EDT 
FRIDAY...

* WHAT...Temperatures in the mid 30s will result in frost formation.

* WHERE...Oswego and Allegany Counties.

* WHEN...From 11 PM this evening to 8 AM EDT Friday.

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

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Take steps now to protect tender plants from the cold.

&&

$$

NYZ007-008-220430-
/O.CON.KBUF.FR.Y.0006.260522T0300Z-260522T1200Z/
Jefferson-Lewis-
Including the cities of Watertown and Lowville
1230 PM EDT Thu May 21 2026

...FROST ADVISORY REMAINS IN EFFECT FROM 11 PM THIS EVENING TO 8 AM 
EDT FRIDAY...

* WHAT...Temperatures in the lower to mid 30s will result in areas 
  of frost formation.

* WHERE...Jefferson and Lewis Counties.

* WHEN...From 11 PM this evening to 8 AM EDT Friday.

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

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Take steps now to protect tender plants from the cold.

&&

$$

TMA
401 
WWUS71 KBUF 220148
NPWBUF

URGENT - WEATHER MESSAGE
National Weather Service Buffalo NY
948 PM EDT Thu May 21 2026

NYZ006-021-221200-
/O.CON.KBUF.FR.Y.0006.260522T0300Z-260522T1200Z/
Oswego-Allegany-
Including the cities of Oswego and Wellsville
948 PM EDT Thu May 21 2026

...FROST ADVISORY REMAINS IN EFFECT UNTIL 8 AM EDT FRIDAY...

* WHAT...Temperatures in the mid 30s will result in frost formation.

* WHERE...Oswego and Allegany Counties.

* WHEN...Until 8 AM EDT Friday.

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

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Take steps now to protect tender plants from the cold.

&&

$$

NYZ007-008-221200-
/O.CON.KBUF.FR.Y.0006.260522T0300Z-260522T1200Z/
Jefferson-Lewis-
Including the cities of Watertown and Lowville
948 PM EDT Thu May 21 2026

...FROST ADVISORY REMAINS IN EFFECT UNTIL 8 AM EDT FRIDAY...

* WHAT...Temperatures in the lower to mid 30s will result in areas 
  of frost formation.

* WHERE...Jefferson and Lewis Counties.

* WHEN...Until 8 AM EDT Friday.

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

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Take steps now to protect tender plants from the cold.

&&

$$

EAJ
906 
WWUS71 KBUF 221159
NPWBUF

URGENT - WEATHER MESSAGE
National Weather Service Buffalo NY
759 AM EDT Fri May 22 2026

NYZ006>008-021-221300-
/O.EXP.KBUF.FR.Y.0006.000000T0000Z-260522T1200Z/
Oswego-Jefferson-Lewis-Allegany-
Including the cities of Oswego, Watertown, Lowville, and
Wellsville
759 AM EDT Fri May 22 2026

...FROST ADVISORY WILL EXPIRE AT 8 AM EDT THIS MORNING...

Temperatures have risen and are no longer supportive of frost 
formation, therefore the Frost Advisory will be allowed to expire.

$$

TMA

What forecasters said that day

The local office's own words before this frost advisory went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Buffalo, NY wrote its last area forecast discussion before this frost advisory went out at May 20, 8:08 PM EDT, 5 hours 2 minutes earlier. Its key messages:

  • 1) Below normal temperatures continue through the end of the week. 2) Widespread soaking rain Friday night into Saturday night.
Area forecast discussion, May 20, 8:08 PM EDT, 5 hours 2 minutes before
Area Forecast Discussion
National Weather Service Buffalo NY
808 PM EDT Wed May 20 2026

.WHAT HAS CHANGED...
No significant changes with this update.

&&

.KEY MESSAGES...
1) Below normal temperatures continue through the end of the week.

2) Widespread soaking rain Friday night into Saturday night.

&&

.DISCUSSION...
KEY MESSAGE 1...Below normal temperatures continue through Saturday.

Cooler air will continue to build into the region behind the passage
of a cold front, with below normal temperatures expected through
Saturday. 850 mb temperatures will fall to the single digits as
high pressure builds across the region. Low temperatures will fall
into the 40s tonight. Some 30s are possible Thursday night as the
high moves overhead resulting in a more favorable set-up for
radiational cooling, especially east of Lake Ontario where areas
of frost will be possible inland from Lake Ontario.

KEY MESSAGE 2...Widespread soaking rain Friday night into Saturday
night.

Confidence continues to increase in a widespread, soaking rain to
start the Memorial Day holiday weekend. A wave of low pressure moves
into the Great Lakes along an advancing warm front from the Ohio
Valley Friday night and Saturday. This will bring a period of
widespread, soaking rain along with possible embedded thunderstorms.
A 40 knot southerly low level jet will send abundant moisture
northward into the region resulting in periods of very efficient,
heavy rainfall Friday night through Saturday, likely lingering
into Saturday night as the warm front lifts north. Current rainfall
amounts for this time period are generally 1-1.5 inches. This
amount of rain will have the potential cause localized ponding
and minor flooding of low lying areas as well as cause rises on
creeks/streams, but widespread flooding is not expected.

&&

.AVIATION /00Z THURSDAY THROUGH MONDAY/...
Mainly VFR flight conditions will prevail through Thursday night as
high pressure builds into the Great Lakes. Cloud cover is expected
to be limited to mid and high decks for most of the period through
Thursday night, but some afternoon fair weather cu at the lower
levels will be possible for Thursday. Winds will veer to the
northwest this evening (if not already there yet) and then to
the northeast through tonight as the high pressure centers over
the Central Great Lakes. Winds will veer to the east Thursday
night as the sfc high passes north of the terminals.

Outlook...

Friday...Mainly VFR.

Saturday...MVFR/VFR deteriorating to MVFR/IFR with widespread rain
showers.

Sunday...MVFR-IFR with rain showers in the morning then improving to
VFR.

Monday...Mainly VFR with a chance of rain showers.

&&

.MARINE...
Elevated northwest winds will continue on Lake Erie and Lake
Ontario into tonight, with the strongest winds on the eastern end
of Lake Ontario. A Small Craft Advisory remains in effect for this
region through this evening. Winds will trend lighter on Lake
Erie, however may be enough to produce choppy conditions.

Winds will relax as high pressure builds into the region Thursday
into Friday.

A stronger pressure gradient develops late Friday and Saturday
as a wave and warm front move into the Great Lakes. Easterly
winds will increase to 15 to 25 knots on the western end of Lake
Ontario with small craft and beach hazards headlines likely
during this time period. Winds will trend weaker on Lake Erie.

&&

.BUF WATCHES/WARNINGS/ADVISORIES...
NY...Beach Hazards Statement until midnight EDT tonight for
     NYZ005>007.
MARINE...Small Craft Advisory until midnight EDT tonight for LOZ043>045.

&&

DISCUSSION...TMA
AVIATION...SW
MARINE...TMA
Hazardous weather outlook, May 20, 2:25 PM EDT, 10 hours 45 minutes before
Hazardous Weather Outlook
National Weather Service Buffalo NY
225 PM EDT Wed May 20 2026

NYZ001>004-008-010>014-019>021-085-211830-
Niagara-Orleans-Monroe-Wayne-Lewis-Northern Erie-Genesee-Wyoming-
Livingston-Ontario-Chautauqua-Cattaraugus-Allegany-Southern Erie-
225 PM EDT Wed May 20 2026

This Hazardous Weather Outlook is for portions of western and north
central New York.

.DAY ONE...This afternoon and tonight.

No hazardous weather is expected at this time.

.DAYS TWO THROUGH SEVEN...Thursday through Tuesday.

No hazardous weather is expected at this time.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not expected at this time.

This product, along with other watches, warnings, advisories, and
statements issued by the National Weather Service office in Buffalo
can be found on the internet at http://www.weather.gov/buf

NYZ005>007-211830-
Northern Cayuga-Oswego-Jefferson-
225 PM EDT Wed May 20 2026

...BEACH HAZARDS STATEMENT IN EFFECT UNTIL MIDNIGHT EDT TONIGHT...

This Hazardous Weather Outlook is for portions of central New York.

.DAY ONE...This afternoon and tonight.

Please listen to NOAA Weather Radio or go to weather.gov on the
Internet for more information about the following hazards.

   Beach Hazards Statement.

.DAYS TWO THROUGH SEVEN...Thursday through Tuesday.

No hazardous weather is expected at this time.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not expected at this time.

This product, along with other watches, warnings, advisories, and
statements issued by the National Weather Service office in Buffalo
can be found on the internet at http://www.weather.gov/buf

LEZ020-040-041-LOZ030-042>045-062>065-SLZ022-024-211830-
Upper Niagara River and Buffalo Harbor-
Lake Erie nearshore waters from Ripley to Dunkirk-
Lake Erie nearshore waters from Dunkirk to Buffalo-
Lower Niagara River-
Lake Ontario nearshore waters from the Niagara River to Hamlin Beach-
Lake Ontario nearshore waters from Hamlin Beach to Sodus Bay-
Lake Ontario nearshore waters from Sodus Bay to Mexico Bay-
Lake Ontario nearshore waters from Mexico Bay to the Saint Lawrence
River-
Lake Ontario open waters from the Niagara River to Hamlin Beach-
Lake Ontario open waters from Hamlin Beach to Sodus Bay-
Lake Ontario open waters from Sodus Bay to Mexico Bay-
Lake Ontario open waters from Mexico Bay to the Saint Lawrence River-
Saint Lawrence River from Cape Vincent to Ogdensburg-
Saint Lawrence River from Ogdensburg to Saint Regis-
225 PM EDT Wed May 20 2026

This Hazardous Weather Outlook is for the New York waters of Lake
Erie, Lake Ontario, and the Saint Lawrence River.

.DAY ONE...This afternoon and tonight.

No hazardous weather is expected at this time.

.DAYS TWO THROUGH SEVEN...Thursday through Tuesday.

No hazardous weather is expected at this time.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not expected at this time.

This product, along with other watches, warnings, advisories, and
statements issued by the National Weather Service office in Buffalo
can be found on the internet at http://www.weather.gov/buf

The office that day

Everything else NWS Buffalo, NY issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 20, 11:50 PM EDTBeach Hazards StatementBUFMonroe, Wayne11 hr

Nearby

Frost Advisories in New York, 2026Every frost advisory in 2026

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.