Major cold shot, first frosts and freezes, 10/17-10/19

[nzucker]

00Z GFS shows increasing support for a PNA spike and associated deep trough in the East, bringing frost/freeze potential to much of the NYC region. 850mb temperatures approach -10C at the height of the outbreak.

[uncle W]

Could you point out those threads for me?

 

How does this potential first freeze in NYC correlate with climo? Is a first freeze on October 18th even noteworthy? 

if it gets to 32 or lower in NYC it would be significant...10/15/1876 is the earliest date with a temp. 32 or lower...

season....first.freeze....last.freeze..

1876-77.......10/15.......4/08

1877-78.......11/07.......3/26

1878-79.......11/05.......4/06

1879-80.......10/25.......4/12

1880-81.......11/18.......4/07

1881-82.......11/22.......4/12

1882-83.......11/03.......4/03

1883-84.......11/12.......4/06

1884-85.......11/19.......4/14

1885-86.......11/01.......4/04

1886-87.......11/07.......4/19

1887-88.......10/30.......4/25

1888-89.......11/17.......3/31

1889-90.......10/24.......4/19

1890-91.......11/21.......5/06

1891-92.......11/04.......4/25

1892-93.......11/11.......3/30

1893-94.......11/15.......4/09

1894-95.......11/07.......4/05

1895-96.......11/12.......4/08

1896-97.......11/23.......4/20

1897-98.......11/18.......4/07

1898-99.......11/24.......4/06

1899-00.......11/12.......4/11

1900-01.......11/15.......3/31

1901-02.......11/10.......3/20

1902-03.......12/05.......4/05

1903-04.......11/07.......4/20

1904-05.......10/31.......3/15

1905-06.......11/14.......4/01

1906-07.......11/29.......4/03

1907-08.......12/03.......4/05

1908-09.......11/04.......4/11

1909-10.......11/30.......3/18

1910-11.......11/20.......4/03

1911-12.......11/03.......4/04

1912-13.......11/03.......3/28

1913-14.......11/11.......4/13

1914-15.......11/10.......4/04

1915-16.......11/18.......4/09

1916-17.......11/15.......4/10

1917-18.......10/31.......4/12

1918-19.......11/24.......4/26

1919-20.......11/14.......4/11

1920-21.......11/12.......4/11

1921-22.......11/06.......4/21

1922-23.......11/21.......4/14

1923-24.......11/09.......4/03

1924-25.......11/16.......4/21

1925-26.......10/29.......4/20

1926-27.......11/04.......3/28

1927-28.......11/07.......4/16

1928-29.......10/30.......3/18

1929-30.......11/22.......4/24

1930-31.......11/05.......3/14

1931-32.......11/07.......4/13

1932-33.......11/20.......3/25

1933-34.......10/26.......3/29

1934-35.......11/14.......4/16

1935-36.......11/23.......4/08

1936-37.......10/26.......3/31

1937-38.......11/21.......4/07

1938-39.......11/24.......4/13

1939-40.......11/13.......4/15

1940-41.......10/19.......3/31

1941-42.......11/25.......2/28

1942-43.......11/13.......4/16

1943-44.......11/15.......4/06

1944-45.......11/23.......3/11

1945-46.......11/21.......3/12

1946-47.......11/23.......3/31

1947-48.......11/19.......4/04

1948-49.......12/11.......3/20

1949-50.......11/22.......4/14

1950-51.......11/16.......3/27

1951-52.......11/03.......3/17

1952-53.......11/29.......3/11

1953-54.......11/06.......4/04

1954-55.......11/10.......3/29

1955-56.......11/19.......3/28

1956-57.......11/10.......3/25

1957-58.......11/11.......4/09

1958-59.......11/28.......3/29

1959-60.......11/17.......3/27

1960-61.......11/07.......3/21

1961-62.......11/10.......3/09

1962-63.......11/07.......3/23

1963-64.......12/01.......4/05

1964-65.......11/21.......4/01

1965-66.......10/29.......3/29

1966-67.......11/04.......4/12

1967-68.......11/08.......4/06

1968-69.......11/21.......4/01

1969-70.......10/23.......4/11

1970-71.......11/23.......3/27

1971-72.......11/08.......4/09

1972-73.......10/20.......3/21

1973-74.......11/10.......4/10

1974-75.......10/19.......4/10

1975-76.......10/31.......4/12

1976-77.......10/27.......4/10

1977-78.......11/14.......4/03

1978-79.......11/25.......4/08

1979-80.......11/30.......4/17

1980-81.......11/16.......3/21

1981-82.......11/25.......4/08

1982-83.......11/13.......3/30

1983-84.......11/13.......3/18

1984-85.......11/19.......4/10

1985-86.......12/02.......3/22

1986-87.......11/13.......4/01

1987-88.......11/11.......3/23

1988-89.......10/31.......3/22

1989-90.......11/18.......3/28

1990-91.......11/09.......4/13

1991-92.......11/26.......4/13

1992-93.......11/08.......3/20

1993-94.......11/21.......3/19

1994-95.......11/23.......4/06

1995-96.......11/09.......3/29

1996-97.......11/12.......4/10

1997-98.......11/13.......3/23

1998-99.......12/22.......3/16

1999-00.......11/30.......4/09

2000-01.......11/20.......3/28

2001-02.......12/16.......4/07

2002-03.......11/27.......4/08

2003-04.......11/09.......4/06

2004-05.......11/09.......3/16

2005-06.......11/18.......3/22

2006-07.......12/04.......4/09

2007-08.......11/11.......3/30

2008-09.......11/18.......3/24

2009-10.......12/07.......3/27

2010-11.......12/04.......3/29

2011-12.......12/10.......3/27

2012-13.......11/06.......3/23

2013-14.......11/12.......4/16

2014-15.......11/18.......4/01

NYC's latest 1st 32 day since 1876...

1998...12/22

2001...12/16

1948...12/11

2011...12/10

2009...12/07

1902...12/05

2010...12/04

2006...12/04

1907...12/03

1985...12/02

1963...12/01

[IsentropicLift]

if it gets to 32 or lower in NYC it would be significant...10/15/1876 is the earliest date with a temp. 32 or lower...

season....first.freeze....last.freeze..

1876-77.......10/15.......4/08

1877-78.......11/07.......3/26

1878-79.......11/05.......4/06

1879-80.......10/25.......4/12

1880-81.......11/18.......4/07

1881-82.......11/22.......4/12

1882-83.......11/03.......4/03

1883-84.......11/12.......4/06

1884-85.......11/19.......4/14

1885-86.......11/01.......4/04

1886-87.......11/07.......4/19

1887-88.......10/30.......4/25

1888-89.......11/17.......3/31

1889-90.......10/24.......4/19

1890-91.......11/21.......5/06

1891-92.......11/04.......4/25

1892-93.......11/11.......3/30

1893-94.......11/15.......4/09

1894-95.......11/07.......4/05

1895-96.......11/12.......4/08

1896-97.......11/23.......4/20

1897-98.......11/18.......4/07

1898-99.......11/24.......4/06

1899-00.......11/12.......4/11

1900-01.......11/15.......3/31

1901-02.......11/10.......3/20

1902-03.......12/05.......4/05

1903-04.......11/07.......4/20

1904-05.......10/31.......3/15

1905-06.......11/14.......4/01

1906-07.......11/29.......4/03

1907-08.......12/03.......4/05

1908-09.......11/04.......4/11

1909-10.......11/30.......3/18

1910-11.......11/20.......4/03

1911-12.......11/03.......4/04

1912-13.......11/03.......3/28

1913-14.......11/11.......4/13

1914-15.......11/10.......4/04

1915-16.......11/18.......4/09

1916-17.......11/15.......4/10

1917-18.......10/31.......4/12

1918-19.......11/24.......4/26

1919-20.......11/14.......4/11

1920-21.......11/12.......4/11

1921-22.......11/06.......4/21

1922-23.......11/21.......4/14

1923-24.......11/09.......4/03

1924-25.......11/16.......4/21

1925-26.......10/29.......4/20

1926-27.......11/04.......3/28

1927-28.......11/07.......4/16

1928-29.......10/30.......3/18

1929-30.......11/22.......4/24

1930-31.......11/05.......3/14

1931-32.......11/07.......4/13

1932-33.......11/20.......3/25

1933-34.......10/26.......3/29

1934-35.......11/14.......4/16

1935-36.......11/23.......4/08

1936-37.......10/26.......3/31

1937-38.......11/21.......4/07

1938-39.......11/24.......4/13

1939-40.......11/13.......4/15

1940-41.......10/19.......3/31

1941-42.......11/25.......2/28

1942-43.......11/13.......4/16

1943-44.......11/15.......4/06

1944-45.......11/23.......3/11

1945-46.......11/21.......3/12

1946-47.......11/23.......3/31

1947-48.......11/19.......4/04

1948-49.......12/11.......3/20

1949-50.......11/22.......4/14

1950-51.......11/16.......3/27

1951-52.......11/03.......3/17

1952-53.......11/29.......3/11

1953-54.......11/06.......4/04

1954-55.......11/10.......3/29

1955-56.......11/19.......3/28

1956-57.......11/10.......3/25

1957-58.......11/11.......4/09

1958-59.......11/28.......3/29

1959-60.......11/17.......3/27

1960-61.......11/07.......3/21

1961-62.......11/10.......3/09

1962-63.......11/07.......3/23

1963-64.......12/01.......4/05

1964-65.......11/21.......4/01

1965-66.......10/29.......3/29

1966-67.......11/04.......4/12

1967-68.......11/08.......4/06

1968-69.......11/21.......4/01

1969-70.......10/23.......4/11

1970-71.......11/23.......3/27

1971-72.......11/08.......4/09

1972-73.......10/20.......3/21

1973-74.......11/10.......4/10

1974-75.......10/19.......4/10

1975-76.......10/31.......4/12

1976-77.......10/27.......4/10

1977-78.......11/14.......4/03

1978-79.......11/25.......4/08

1979-80.......11/30.......4/17

1980-81.......11/16.......3/21

1981-82.......11/25.......4/08

1982-83.......11/13.......3/30

1983-84.......11/13.......3/18

1984-85.......11/19.......4/10

1985-86.......12/02.......3/22

1986-87.......11/13.......4/01

1987-88.......11/11.......3/23

1988-89.......10/31.......3/22

1989-90.......11/18.......3/28

1990-91.......11/09.......4/13

1991-92.......11/26.......4/13

1992-93.......11/08.......3/20

1993-94.......11/21.......3/19

1994-95.......11/23.......4/06

1995-96.......11/09.......3/29

1996-97.......11/12.......4/10

1997-98.......11/13.......3/23

1998-99.......12/22.......3/16

1999-00.......11/30.......4/09

2000-01.......11/20.......3/28

2001-02.......12/16.......4/07

2002-03.......11/27.......4/08

2003-04.......11/09.......4/06

2004-05.......11/09.......3/16

2005-06.......11/18.......3/22

2006-07.......12/04.......4/09

2007-08.......11/11.......3/30

2008-09.......11/18.......3/24

2009-10.......12/07.......3/27

2010-11.......12/04.......3/29

2011-12.......12/10.......3/27

2012-13.......11/06.......3/23

2013-14.......11/12.......4/16

2014-15.......11/18.......4/01

NYC's latest 1st 32 day since 1876...

1998...12/22

2001...12/16

1948...12/11

2011...12/10

2009...12/07

1902...12/05

2010...12/04

2006...12/04

1907...12/03

1985...12/02

1963...12/01

Most of the guidance I have looked at only gets NYC down into the mid-upper 30's while the interior briefly dips below freezing. The first frost IMBY is actually a little late this year.

[nzucker]

The 0z ECM shows a very cold Sunday night for those areas that radiate well.

Could see record-breaking temperatures which is worthy of separate discussion. Best chance for NYC to get an early frost or freeze may be Saturday night with cold air advection as Sunday night the high is right overhead, and Central Park doesn't drop fast with light winds.

For urban areas to get a freeze in mid-October would be noteworthy. For my area, we usually hit freezing from 10/20-10/25. However, could get into the 20s with this one.

It's been a while since we've seen 850s of -10C in mid October. Even the 2009 outbreak was not as cold as this is modeled.

[IsentropicLift]

The 0z ECM shows a very cold Sunday night for those areas that radiate well.

Could see record-breaking temperatures which is worthy of separate discussion. Best chance for NYC to get an early frost or freeze may be Saturday night with cold air advection as Sunday night the high is right overhead, and Central Park doesn't drop fast with light winds.

For urban areas to get a freeze in mid-October would be noteworthy. For my area, we usually hit freezing from 10/20-10/25. However, could get into the 20s with this one.

It's been a while since we've seen 850s of -10C in mid October. Even the 2009 outbreak was not as cold as this is modeled.

I guess my other point is that it's 5+ days away. More often than not extreme cold shots in October become muddled as we get closer. Clmo suggests that we're still about 2 weeks away from first frost in the city.

[Brian5671]

Uptong only going for a high of 50 here Sunday. 

[Cfa]

Could you point out those threads for me?

How does this potential first freeze in NYC correlate with climo? Is a first freeze on October 18th even noteworthy?

NYC typically sees its first freeze in late November, so a mid October freeze is very noteworthy, about as noteworthy as a first freeze around the winter solstice.

It's too early to be dealing with this.

[Allsnow]

Growing season is about to end

[winterwx21]

Growing season is about to end

I hope it stays just above frost level. My vegetable garden is still producing. Would like to extend it another week or two. I'm not sure what the point is of rooting for an early frost/freeze, since it doesn't mean we're gonna see snow. But everyone is entitled to their opinion. 

[IsentropicLift]

The 12z GFS keeps the coastal plain above freezing.

 

[Isotherm]

I hope it stays just above frost level. My vegetable garden is still producing. Would like to extend it another week or two. I'm not sure what the point is of rooting for an early frost/freeze, since it doesn't mean we're gonna see snow. But everyone is entitled to their opinion. 

 

 

Ragweed and bugs.

[SnoSki14]

I don't see my region going below 34-35F taking moderation into consideration. Forecast air masses do get diluted the closer we get to the date of occurrence minus a few exceptions.

[forkyfork]

Growing season is about to end

most plants look worn out and depressing except for the tropicals like lantana. bring on a frost

[uncle W]

this will be around the same time as the first cold shot in 2009...

for the record 2009 holds the coldest max for the date...the low was in the upper 30's...1972 had its first cold shot with a little snow for good measure...1968 was still mild with a 78 degree day...

NYC's almanac for 10/18.
Highest max. Lowest max. Highest min. Lowest min. Max. Precipitation. snowfall
82 in 1928.....45 in 2009.....69 in 1928.....35 in 1929.....2.45" in 1911.....trace in 1972
79 in 1899.....48 in 1909.....67 in 1899.....35 in 1939.....2.09" in 1932
79 in 1908.....50 in 1901.....66 in 1947.....35 in 1974.....1.91" in 1927
79 in 1945.....50 in 1926.....64 in 1968.....37 in 1972
78 in 1968.....50 in 1989.....63 in 2007.....37 in 1978

[winterwx21]

I don't see my region going below 34-35F taking moderation into consideration. Forecast air masses do get diluted the closer we get to the date of occurrence minus a few exceptions.

 

 

I agree ... mid 30s should about do it here. My tomato plants will be just fine, and it looks as if there will be a nice warmup after this cool shot passes. I look forward to colder weather, but not until November. Many years I'm able to keep getting stuff from my vegetable garden until close to November 1st. Hoping that'll happen this year. 

[Isotherm]

Overnight lows will depend upon your location, elevation and the extent to which your area is rural. I recorded a low of 42.9F on October 6th in a +10c 850mb airmass. This past weekend I had a 37F low with 850's around +5c. Thus, given 850mb temperatures at or below 0c, 32F / freeze should be a lock for my area, assuming winds can decouple. If some of the modelling is correct with -3 / -4c or cooler 850s, we have a shot at the 20s.

[uncle W]

this will be around the same time as the first cold shot in 2009...

for the record 2009 holds the coldest max for the date...the low was in the upper 30's...1972 had its first cold shot with a little snow for good measure...1968 was still mild with a 78 degree day...

NYC's almanac for 10/18.

Highest max. Lowest max. Highest min. Lowest min. Max. Precipitation. snowfall

82 in 1928.....45 in 2009.....69 in 1928.....35 in 1929.....2.45" in 1911.....trace in 1972

79 in 1899.....48 in 1909.....67 in 1899.....35 in 1939.....2.09" in 1932

79 in 1908.....50 in 1901.....66 in 1947.....35 in 1974.....1.91" in 1927

79 in 1945.....50 in 1926.....64 in 1968.....37 in 1972

78 in 1968.....50 in 1989.....63 in 2007.....37 in 1978

35 is the record for the date in NYC...at this point we have a shot but most of the time early guidance is over done...1972 and 1974 recorded their lows at midnight...

[LongBeachSurfFreak]

Overnight lows will depend upon your location, elevation and the extent to which your area is rural. I recorded a low of 42.9F on October 6th in a +10c 850mb airmass. This past weekend I had a 37F low with 850's around +5c. Thus, given 850mb temperatures at or below 0c, 32F / freeze should be a lock for my area, assuming winds can decouple. If some of the modelling is correct with -3 / -4c or cooler 850s, we have a shot at the 20s.

I agree. The big show is outside the city and especially the prime radiating spots on Sunday night. West Hampton could easily drop in to the mid 20s

And don't forget our favorite the park folliage which will further reduce what little radiational cooling it gets

[nzucker]

12z GFS shows some pretty nasty cold (and windchills) from CAA for Sunday morning 7am:

 

Monday morning should be especially cold for locations that radiate well, as the 1032mb high pressure crests overhead...850s are actually -6C on this frame:

 

I think the posters in NJ will get a freeze one of those nights. Will be tough for Central Park as the CAA may be a tad bit late, peaking Sunday morning as the sun rises, although Sunday highs will probably stay in the 40s so might have a chance that night as the high crests over...won't take much to get from the upper 40s to 32F.

 

It's pretty much a lock that Westchester, SW CT, Long Island, and NNJ will experience a hard frost, if not a freeze, this weekend.

 

 

 

[Redmorninglight]

Monday morning could be interesting to see the spread in temps considering the Pine Barrens of NJ (check out Millville, NJ) and NY likely hitting mid 20s and urban areas and immediate coast in the 40s.  Still looks like record cold for NYC Sunday morning.

[SnoSki14]

Monday morning could be interesting to see the spread in temps considering the Pine Barrens of NJ (check out Millville, NJ) and NY likely hitting mid 20s and urban areas and immediate coast in the 40s. Still looks like record cold for NYC Sunday morning.

They'll definitely be a good spread for sure. I do think a lot of NJ spots get into the 20s and low 30s.

[LongBeachSurfFreak]

Again all this happens after record warmth. Not brining in the CC talk but damn good time to be a weather lover.

I just don't think the 850s are anywhere cold enough for a fully vegetated park to get any where near 32. More like 38

[nzucker]

Monday morning could be interesting to see the spread in temps considering the Pine Barrens of NJ (check out Millville, NJ) and NY likely hitting mid 20s and urban areas and immediate coast in the 40s. Still looks like record cold for NYC Sunday morning.

Doubt anyone stays in the 40s for lows, will be 30s to the coast Monday AM. 850s are -6C with a 1032mb high overhead, and high temperatures Sunday struggle to 50F. NYC/EWR might be 33-36F while colder areas are in the low to mid 20s.

[nzucker]

06z GFS has trended colder for Monday morning. NYC's 850mb temps are -9C, instead of -6C on yesterday's 18z run, with the 1032mb high overhead at 7am Monday. Looks as if the high moves off the coast more slowly, so we have a second cold morning.

NYC is now almost a lock for a 34-36F frost, with a good possibility for a freeze. All suburbs that radiate decently should see 20s.

[Isotherm]

Beginning to think Monday night might actually be the coldest night for radiating locations in surburbia rather than Sunday night. With the slower eastward movement of the surface high, winds might have trouble decoupling Sunday night. We'll see. I think it's a lock for the first freeze in suburbia on one or both of those nights (Sun/Mon). NYC should be a lock for sub 40F.

[PB GFI]

[Animal]

06z GFS has trended colder for Monday morning. NYC's 850mb temps are -9C, instead of -6C on yesterday's 18z run, with the 1032mb high overhead at 7am Monday. Looks as if the high moves off the coast more slowly, so we have a second cold morning.

NYC is now almost a lock for a 34-36F frost, with a good possibility for a freeze. All suburbs that radiate decently should see 20s.

 

Mt Holly NWS is going with a low of around 30 to 32 on Sunday and Monday morning for most locations on the point and click in Sussex County NJ. They are  forecasting the first wide spread freeze for northern New Jersery & parts of eastern Pennsylvania.

[nzucker]

Beginning to think Monday night might actually be the coldest night for radiating locations in surburbia rather than Sunday night. With the slower eastward movement of the surface high, winds might have trouble decoupling Sunday night. We'll see. I think it's a lock for the first freeze in suburbia on one or both of those nights (Sun/Mon). NYC should be a lock for sub 40F.

Tuesday morning on the newer model runs looks more like Monday morning looked on the older model runs with the slower movement of the surface features. That could be the coldest night for locations that radiate well as the 1032mb high moves overhead and then offshore.

The only thing is that 850s climb rapidly from -9C Monday morning to 0C Tuesday morning. I wonder if there will be any high clouds from increasing WAA.

In any case, we now have the potential for 3 very cold nights instead of 2. The latest runs also have -10C 850s nearing the region Monday morning, so it has trended MUCH colder. There's definitely a good chance for a NYC freeze and the 5 boroughs will certainly have some frost. Outlying suburbs are a lock for at least one hard freeze, if not 2-3 in colder areas with elevation.

[uncle W]

The Euro 2m temps along with the GFS MOS both have a low of 36 on 10/19 in NYC.

A low that cold would put  it near 4th or 5th place for the day.

 

10/19

30 in 1940

32 in 1974

34 in 1976

NYC's almanac for 10/19.

Highest max. Lowest max. Highest min. Lowest min. Max. Precipitation..snowfall

83 in 1963.....43 in 1972.....68 in 1905.....30 in 1940.....4.35" in 1996.....Trace in 1940

81 in 1965.....45 in 1940.....65 in 2007.....32 in 1974.....3.12" in 1966.....Trace in 1972

80 in 1945.....49 in 1880.....64 in 1928.....34 in 1976.....1.41" in 1989

79 in 1928.....49 in 1992.....64 in 1902.....35 in 1972.....1.27" in 1911

76 in 1961.....49 in 1974.....64 in 1947.....35 in 1922.....1.12" in 2011

35 is the fifth coldest for the date...el nino years hold the coldest and warmest temperatures for the date...1963, 1965 for warm and 1940, 1972 and 1976 for cold...Here's the farmers almanac forecast for the 1972-73 winter...

[IsentropicLift]

The 12z GFS keeps most areas in the 40's on Sunday and Monday, even coastal sections.  Then a slight moderation occurs next week before another trough reloads into the Lakes next weekend.