September 2025 OBS-Discussion centered NYC subforum

[LibertyBell]

15 hours ago, bluewave said:

It’s certainly underperforming model forecasts as this dry pattern since last fall has been very persistent. 
 

Instead of looking at models, perhaps it's better to look at storm tracks, when a storm tracks to our NW we typically see more scattered precipitation.  Those 2-4 inch amounts were very unrealistic.

Our rainfall pattern is cycling back to where we were in the 80s.

[LibertyBell]

15 hours ago, bluewave said:

The new RRFS A has been maintaining that trajectory for days now with the heaviest focused to our NW. It’s still considered an experimental forecast so doesn’t really get included in the mix during forecast discussions.

It could be that the warmer conditions with the record 70° lows resulted in the front stalling a little more to the NW of the very wet models like the Canadian suite focusing the max right through our area.

So the stalled front would up further north than the wetter models.

But the storm itself is tracking to our NW so this can't be a surprise.

 

[LibertyBell]

14 hours ago, SACRUS said:

 

 

Records:

Highs:

EWR: 91 (1970)
NYC: 90 (1970)
LGA: 90 (2010)
JFK: 87 (2010)


Lows:

EWR: 39 (1950)
NYC: 40 (1887)
LGA: 42 (1950)
JFK: 45 (1989)

Historical:

 

1848 - The Great Gale of 1848 was the most severe hurricane to affect Tampa Bay, Florida and is one of two major hurricanes to make landfall in the area. This storm produced the highest storm tide ever experienced in Tampa Bay when the water rose 15 feet in six to eight hours.

1848: The Tampa, FL area was hit by a major hurricane. The pressure plunged to 28.18 inches of mercury and the storm surge reached 15 feet. The army post in the area was wiped out. (Ref. Wilson Wx. History)

1926: The coldest temperature ever recorded in Scottsbluff, NE for the month of September occurred on this with a low of 14°, while Chadron, NE recorded their lowest September temperature with 15°. Western Yellowstone, MT recorded -9 °F which was then the lowest temperature reading in the 48 states for September. (Ref. AccWeather Weather History)


1929: Willmar, MN experiences a deluge that dropped 5.22 inches of rain in 24 hours. (Ref. AccWeather Weather History)

1939 - A west coast hurricane moved onshore south of Los Angeles bringing unprecedented rains along the southern coast of California. Nearly five and a half inches of rain drenched Los Angeles during a 24 hour period. The hurricane caused two million dollars damage, mostly to structures along the coast and to crops, and claimed 45 lives at sea. ""El Cordonazo"" produced 5.66 inches of rain at Los Angeles and 11.6 inches of rain at Mount Wilson, both records for the month of September. (David Ludlum) (The Weather Channel)


1942: The earliest first trace of snow in Chicago occurred on this date in 1942 and 1928.  First snow of the season Average; October 30 Earliest; September 25 (1928 and 1942) Latest; December 5, 1999 First measurable snow (.1 inches or more) of the season Average; November 16 Earliest; October 12, 2006 Latest; December 16, 1965 Snow Trivia for Chicago - NWS

1953: The center of Hurricane Florence hit the northwest Florida coast between Valparaiso and Panama City near midday with wind maximum sustained winds near 80 mph with gusts to 90 mph and heavy rainfall. The Pensacola Weather Bureau Office reported winds of up to 75 mph early the next morning. The storm passed inland over a sparsely settled area of Florida and this probably accounts for the rather small amount of damage. In Franklin and Okaloosa Counties the Red Cross estimated that 273 homes were destroyed, 145 other buildings damaged, and three destroyed. A fishing trawler, the "Miss Tampa" was reported missing in the storm's wake. (Ref. Wilson Wx. History)

1962: The remnants of Tropical Storm Claudia of 1962 dumped up to 7 inches of rain in the desert west of Tucson, AZ, causing severe flooding. By the year 2010 there had already been six storms by the name of Claudia. (Ref. Wilson Wx. History)

1975: On September 25 and 26 Elloise gave Hayfield secondary School 5.58 inches rain that closed Fairfax County schools September 26th 1975. The remnants of Hurricane Eloise combined with a cold front and produced very heavy rainfall in the Mid-Atlantic. Washington, DC reported 9.08" of rainfall. Total damage for Virginia was estimated to be $17.2 million. (Ref. Washington Weather Records - KDCA)

1976: Up to 3 inches of rain fell on Tucson, Arizona. About a dozen cars, some occupied, were swept down the washes, resulting in one death. Two boys were carried down the Rillito River for a mile before they could reach ground after their car was swept away. Talk about lucky! (Ref. AccWeather Weather History)

1984: Sheridan, WY recorded their coldest September temperature on record when they fell to 6°. 21 inches of snow fell at Sheridan between the 23rd and the 27th. This made it their snowiest September on record. Other record lows included: Cheyenne, WY: 17°, Casper, WY: 20° and Rapid City, SD: 24°. (Ref. Wilson Wx. History)

1987 - Hurricane Emily crossed the island of Bermuda during the early morning. Emily, moving northeast at 45 mph, produced wind gusts to 115 mph at Kindley Field. The thirty-five million dollars damage inflicted by Emily made it the worst hurricane to strike Bermuda since 1948. Parts of Michigan and Wisconsin experienced their first freeze of the autumn. Snow and sleet were reported in the Sheffield and Sutton areas of northeastern Vermont at midday. (The National Weather Summary) (Storm Data)

1988 - Low pressure off the Northern Pacific Coast brought rain and gale force winds to the coast of Washington State. Fair weather prevailed across most of the rest of the nation. (The National Weather Summary)

1989 - Twenty-three cities in the south central U.S. reported record low temperatures for the date, including Topeka KS with a reading of 33 degrees, and Binghamton NY with a low of 25 degrees. Showers and thunderstorms in the southeastern U.S. drenched Atlanta GA with 4.87 inches of rain, their sixth highest total of record for any given day. (The National Weather Summary) (Storm Data)

1993: In both human and economic terms the Great Flood of 1993 was the most devastating in modern U.S. history. It was a catastrophe across portions of 9 states with losses estimated up to $20 billion dollars. Over 50,000 homes were damaged or destroyed forcing the evacuation of some 54,000 people. In all the floods took 50 lives. Water level records were set at 49 places on the Missouri River system and at 43 places on the upper Mississippi River system. The flood was notable for its duration as well as its size. Flooding began in March with record floods beginning in May and continued into September. (Ref. Wilson Wx. History)

1994: Hail to 1 inch diameter was pounding Hebron, NE. A man ventured out into the storm to release a dog tied to a tree. Lightning killed the man and injured a woman at the scene. The dog was unhurt. (Ref. Weather Guide Calendar with Phenomenal Weather Events 2011 Accord Pub. 2010, USA)

1996: An early season snowstorm brought the season’s first snow to the Front Range eastern foothills in northern Colorado. Heavy snowfall totals included: 8 to 12 inches near Conifer, 7 inches at Floyd Hill, 6 inches at Bailey & Chief Hosa and 4.7 inches at Denver.
Heavy rain fell in the Blackwell area of north-central Oklahoma beginning the previous day through this date, causing many roads to be closed. National Weather Service radar estimated that more than three inches of rain fell in less than 90 minutes in central Kay County, late in the evening. The two day rainfall in Blackwell totaled 9 inches. (Ref. Wilson Wx. History)
 

1998: By the 5 PM ET advisory, 4 hurricanes were spinning simultaneously in the Atlantic basin: Georges, Ivan, Jeanne, and Karl. That was the first time this had happened since 1893. After moving along the north coast of Cuba the previous day, Georges crossed the Florida Keys, heading into the Gulf of Mexico. The storm had re-intensified with winds of 105 mph when it made landfall near Key West, FL midday. (Ref. AccWeather Weather History)

1998 - Four hurricanes were spinning simultaneously in the Atlantic basin: Georges, Ivan, Jeanne, and Karl. That was the first time this had happened since 1893.

2004: Jeanne after performing a complete loop over the open Atlantic, it headed westwards, strengthening into a Category 3 hurricane. Jeanne passed over the islands of Great Abaco and Grand Bahama in the Bahamas on September 25. Jeanne made landfall later in the day of the 25th in Florida just 2 miles (3 kilometers) from where Frances had struck 3 weeks earlier. Building on the rainfall of Frances and Ivan, Jeanne brought near-record flood levels as far north as West Virginia and New Jersey before its remnants turned east into the open Atlantic. Jeanne is blamed for at least 3,006 deaths in Haiti with about 2,800 in Gonaïves alone, which was nearly washed away by floods and mudslides. The storm also caused 7 deaths in Puerto Rico, 18 in the Dominican Republic and at least 4 in Florida, bringing the total number of deaths to at least 3,025. Final property damage in the United States was $6.8 billion, making this the 13th costliest hurricane in U.S. history. Hurricane Jeanne's Track - Weather Underground (Ref. More on Hurricane Jeanne)

1993: In both human and economic terms the Great Flood of 1993 was the most devastating in modern U.S. history. It was a catastrophe across portions of 9 states with losses estimated up to $20 billion dollars. Over 50,000 homes were damaged or destroyed forcing the evacuation of some 54,000 people. In all the floods took 50 lives. Water level records were set at 49 places on the Missouri River system and at 43 places on the upper Mississippi River system. The flood was notable for its duration as well as its size. Flooding began in March with record floods beginning in May and continued into September. (Ref. Wilson Wx. History)

 

wow this was still going on?

 

[LibertyBell]

12 hours ago, AdMC said:

I'm not so sure its the models that are bad, but rather the (lack of) initialization data that is being fed into them:

https://www.cbsnews.com/news/doge-cuts-nws-balloon-sites-leave-us-without-crucial-weather-data-some-meteorologists-say/

Yep, we have to make our own forecasts now, the way they used to do it

[LibertyBell]

9 hours ago, bluewave said:

100° days have been arriving earlier in recent years making June 100° heat more common than late August into September.

we're also due for a 1983 like summer where you can be 95-100 from June through September

[LibertyBell]

9 hours ago, FPizz said:

Some blue skies peeking through the clouds here

we had mostly sunny skies for awhile really nice

[LibertyBell]

6 hours ago, Sundog said:

Major improvement on the 20z HRRR compared to 19z. Still weakens it though, but 19z fizzled it out everywhere. 

on air mets said the *improvements* happened because we got more sunshine than expected this afternoon lol

[winterwx21]

All the humidity this week and we couldn't even get a quarter inch of rain out of it. Frustrating. I'm sure the moderate drought will be expanding across the area over the next couple weeks. Hopefully it won't get as bad as it was last fall. 

[doncat]

0.17" here, was expecting more like 1.50".

[bluewave]

Many stations had two consecutive lows of 70° on the 24th and 25th. This is the 2nd latest on record for spots like Islip. The lastest was 10-08 and 10-09 back in 2017.

Islip Area, NY
Period of record: 1963-09-05 through 2025-09-25

Highest minimum temperatures (degrees F)Top Record 2nd Record 3rd Record

 

9/24	70 in 2025	69 in 1970	67 in 2011+
9/25	72 in 1970	71 in 2025	67 in 2011

 

10/8	72 in 2005	71 in 2017	67 in 1990
10/9	71 in 2017	69 in 1990	62 in 2018+

[steve392]

Muggy 66 degree's going to work this morning.  

[winterwarlock]

.26 here

 

Epic bust

[Sundog]

10 minutes ago, winterwarlock said:

.26 here

 

Epic bust

A pathetic 0.19 here. 

I'm hoping the Saturday night batch actually materializes. 

[MANDA]

Picked up .27" last 24 hours.  Three day event total = .63".  Disappointing but at least no runoff and it all soaked in.  Overall the dry pattern continues.  Some places drier than others but the overall pattern has been dry.  Unless there is a surprise it does not look like the tropics will deliver anything over the next week up this way.

[steve392]

Skies are clearing and its turning into a gorgeous morning so far.  

[MANDA]

Three day event totals:

[Brian5671]

42 minutes ago, MANDA said:

Picked up .27" last 24 hours.  Three day event total = .63".  Disappointing but at least no runoff and it all soaked in.  Overall the dry pattern continues.  Some places drier than others but the overall pattern has been dry.  Unless there is a surprise it does not look like the tropics will deliver anything over the next week up this way.

I'll file this one under "better than nothing" but wow what a 24 hr bust by the models

[FPizz]

.32" total

[NEG NAO]

How dry we will most likely be the next few weeks in NYC metro- quite a few trees leaves are just turning from green to brown and are falling off already........

[donsutherland1]

September 16-30, 2025 is well on track to record a mean temperature of 70.0° or above at Central Park. It would become the 12th such case since regular recordkeeping began in 1869.
This warmth during the second half of September has often coincided with warmer than normal Octobers, both against the historic baseline and the 1991-2020 baseline. It has also typically been followed by warmer winters, particularly against the historic baseline. 

However, three of the four winters that followed such second half of September warmth since 2000 topped the 1991-2020 winter baseline.

The coefficient of determination between the September 16-30 mean temperature and October and winter mean temperatures is exceptionally low (< 0.04), suggesting no predictive power when it comes to forecasting October and winter values. 

However, an alternative measure (ROC AUC) for addressing whether October and winter would be warmer/colder than specified values given a September 16-30 mean temperature shows stronger relationships, particularly for October. In general, ROC AUC is for problems where one wants a yes/no outcome and a probability (e.g., will winter be warmer than 36.2°?).

ROC AUC Scores:

October Outcome:
Mean > 57.2°: 0.729 (moderately-strong)
Mean > 57.9°: 0.714 (moderate)
Mean of 60.0° or above: 0.625

Favored Range: 59.0°-60.0°

December-February Outcome:
Mean > 32.6°: 0.650
Mean > 36.2°: 0.667 
Mean of 40.0° or above: 0.450

Favored Range: 37.5°-39.5°

Note: 0.50 is no better than a random guess (no skill). Values < 0.50 include inverse outcomes at increasing skill for lower values.

The latest CFSv2 shows a warmer than normal winter for the New York City area:

Key Limitations:

1. Sample size is small
2. Mean anomalies do not exclude variability
3. Skill is modest (statistical and model)
4. Outcomes shown do not assess snowfall prospects, but all 11 prior cases saw 20" or more seasonal snowfall.

 

[steve392]

24 minutes ago, MANDA said:

Three day event totals:

That 1.07" is right near me.  Seems like an outlier compared to everyone else.  Either way it was a good rain to feed the plants and grasses.  

[psv88]

Nice weekend on tap. Talk about a bust

[Dark Star]

10 hours ago, LibertyBell said:

Instead of looking at models, perhaps it's better to look at storm tracks, when a storm tracks to our NW we typically see more scattered precipitation.  Those 2-4 inch amounts were very unrealistic.

Our rainfall pattern is cycling back to where we were in the 80s.

An old saying, "Live by the LFM, die by the LFM".  Now we have multiple models, but it comes down to the forecaster to judge what will actually occur based on experience.  Easier said than done.

[jm1220]

29 minutes ago, NEG NAO said:

How dry we will most likely be the next few weeks in NYC metro- quite a few trees leaves are just turning from green to brown and are falling off already........

Greater than 50-50 chance IMO the Sat overnight into Sun rain just gets confluenced/crushed south. We recently had a situation where the north end of one of these just dried up and models were too aggressive. Happens all the time in these confluence situations-dry air just eats up any precip and models are over-aggressive bringing it north. 

[SACRUS]

 

72 / 67 clear.   Low / mid 80s and a chance to get to 80 the next 4, including today which would make it 7 straight for the warmest areas.  Clouds the factor Sat-Sun.  Showers / storms possible overnight Sat into Sun but drying/clearing by the sunday day break.   Humberto / Imelda next week with what should be Imelda going into the S/C Carolina borders and we'll see if anything comes up this way eventually in the 105-10/7 period..   Overall warm here through he 10th, could see some brief cool down between the 1-3 with E/NE/ENE flow for 2 days.  By the 10th trough into the northeast looks shortlived - overall warmer beyond there.

 

[Stormlover74]

2 minutes ago, jm1220 said:

Greater than 50-50 chance IMO the Sat overnight into Sun rain just gets confluenced/crushed south. We recently had a situation where the north end of one of these just dried up and models were too aggressive. Happens all the time in these confluence situations-dry air just eats up any precip and models are over-aggressive bringing it north. 

Especially when its the nam showing the rain coming furthest north

[SACRUS]

 

Records:

 

Highs:

EWR: 90 (2007)
NYC: 91 (1970)
LGA: 90 (2007)
JFK: 87 (1970)



Lows:  

EWR: 40 (1940)
NYC: 42 (1940)
LGA: 44 (1947)
JFK: 47 (1949)

Historical:

 

1936 - Denver, CO, was buried under 21.3 inches of snow, 19.4 inches of which fell in 24 hours. The heavy wet snow snapped trees and wires causing seven million dollars damage. (26th-27th) (David Ludlum) (The Weather Channel)

 

1936: The heaviest snowfall ever recorded in September and the heaviest snowfall ever recorded so early in the season dumped a total of 16.5 inches of snow on downtown Denver and 21.3 inches at Denver Municipal Airport. The 15.0 inches of snow measured from 6:00 PM on the 27th to 6:00 PM on the 28th is the greatest 24-hour snowfall ever recorded in September. This was the first snow of the season. The snow was intermittent on the 26th, but continuous from early afternoon on the 27th to around midnight on the 28th, except for a period of rain during the afternoon of the 28th.

1936:  A forest fire burned several miles east of the town of Brandon, Oregon. The fire was far enough away that residents were not particularly worried. A sudden shift in the winds drove the flames westward and through town. The fire, caused by summer drought and fueled by the abundant Gorse Weed found in many of the empty spaces between buildings in Bandon, caused so much destruction that only a handful of structures were left standing when the fire finally died down. 

1936 - A forest fire burned several miles east of the town of Bandon, Oregon. The fire was far enough away that residents were not particularly worried. A sudden shift in the winds drove the flames westward and through town. The fire, caused by summer drought and fueled by the abundant Gorse Weed found in many of the empty spaces between buildings in Bandon, caused so much destruction that only a handful of structures were left standing when the fire finally died down.

1942: A severe freeze was experienced across the upper Plains and Midwest from the 26th to the 28th. The temperature at Parshall, ND dropped to a record low of 4° on this date. Winona, MN dropped to 25°, their coldest September temperature. Also on this date, snow fell across parts of Minnesota, Iowa and Wisconsin. Locations recording their earliest measurable snowfall included: Caledonia, MN: 5 inches, Fayette, IA: 1 inch and La Crosse, WI: 0.2 of an inch. Snow fell in early morning, mostly melting as it fell. (Ref. AccWeather Weather History)
 

1950 - Residents of the northeastern U.S. observed a blue sun and a blue moon, caused by forest fires in British Columbia. (David Ludlum)

1953: The center of Hurricane Florence hit the northwest Florida coast between Valparaiso and Panama City near midday with wind maximum sustained winds near 80 mph with gusts to 90 mph and heavy rainfall. The Pensacola Weather Bureau Office reported winds of up to 75 mph early the next morning. The storm passed inland over a sparsely settled area of Florida and this probably accounts for the rather small amount of damage. In Franklin and Okaloosa Counties the Red Cross estimated that 273 homes were destroyed, 145 other buildings damaged, and three destroyed. A fishing trawler, the "Miss Tampa" was reported missing in the storm's wake. (Ref. Wilson Wx. History)

 

1955: On this date, the Atlantic reconnaissance aircraft, ”Snowcloud Five” went down while investigating Hurricane Janet and was never heard from again. Lt. Comdr. Windham with a crew of 8 and two newspapermen reported that they were about to begin penetrating the central core of the hurricane.  The hurricane made landfall at peak intensity near Chetumal, Mexico on September 29th. Janet's landfall as a Category 5 hurricane on the Yucatán Peninsula was the first recorded instance that a storm of such intensity in the Atlantic made landfall on a continental mainland; prior to Janet, landfalls of Category 5 intensity were only known to have taken place on islands.

1963 - San Diego, CA, reached an all-time record high of 111 degrees. Los Angeles hit 1S09 degrees. (David Ludlum)

1970 - Santa Ana winds brought fires to Los Angeles County, and to points south and east. Half a million acres were consumed by the fires, as were 1000 structures. Twenty firemen were injured. (25th-29th) (The Weather Channel)

1971: Project Stormfury was an attempt to weaken tropical cyclones by flying aircraft into them and seeding with silver iodide. The project was run by the United States Government from 1962 to 1983. Hurricane Ginger in 1971 was the last hurricane Project Stormfury seeded.

1979 - In the midst of a hot September for Death Valley, California, the afternoon high was 104 degrees for the second of three days, the coolest afternoon highs for the month. (The Weather Channel)

1985: Hurricane Gloria weakened briefly while moving from northeast of the Bahamas to just off the southern North Carolina coast by days end. Gloria peaked the previous day with maximum sustained winds of 145 mph and a minimum central pressure of 920 millibars or 27.17 inches of mercury. Gloria weakened during this date to 90 mph at 06z and 12z before regaining strength intensifying to 100 mph by days end. Washington, DC area was lucky as hurricane Gloria stays well east of Washington, DC. (Ref. Wilson Wx. History)

1987 - Freezing temperatures were reported in the Northern and Central Appalachians, and the Upper Ohio Valley. The morning low of 27 degrees at Concord NH tied their record for the date. Temperatures soared into the 90s in South Dakota. Pierre SD reported an afternoon high of 98 degrees. (The National Weather Summary)

1988 - Unseasonably warm weather prevailed across Florida. Afternoon highs of 92 degrees at Apalachicola and 95 degrees at Fort Myers were records for the date. (The National Weather Summary)

1989 - Rain spread from the southeastern states across New England overnight. Cape Hatteras NC reported measurable rainfall for the fourteenth straight day, with 15.51 inches of rain recorded during that two week period. Phoenix AZ reported a record high of 108 degrees, and a record 134 days of 100 degree weather for the year. Afternoon temperatures were only in the 40s over parts of northwest Wisconsin and Upper Michigan. (The National Weather Summary)

1998: Record warm weather across the Great Lakes and Ohio Valley fueled a severe weather outbreak as a cold front arrived during the late afternoon. A severe thunderstorm produced softball-sized hail in Clare County which smashed skylights, dented automobiles, and damaged roofs and antennas. Damage was estimated at up to half a million dollars. Record highs for the date included: Toledo, OH: 92°, Columbus, OH: 92°, Detroit, MI: 91°, Cleveland, OH: 91°, South Bend, IN: 91°-Tied, Flint, MI: 90°, Chicago, IL: 90°, Grand Rapids, MI: 89°, Lansing, MI: 89°, Jackson, KY: 87° and Mansfield, OH: 87°-Tied. (Ref. Wilson Wx. History)


1998: There were four hurricanes were spinning simultaneously in the Atlantic basin: Georges, Ivan, Jeanne, and Karl. That was the first time this had happened since 1893. 

2004 - After making its infamous loop east of the Bahamas, Hurricane Jeanne made landfall the night of September 26th, 2004. Jeanne came ashore as a major category 3 hurricane just a few miles away from where Hurricane Frances made landfall a few weeks before. Jeanne produced extensive damage along the east central Florida coast from Volusia County south to Martin County. The highest wind gusts occurred over extreme Southern Brevard County as well as Indian River County with 110 - 120 mph estimates at the peak of the storm. (NWS, Melbourne, FL)

[STORMANLI]

0.75"

Should have lowered my expectations. 

[SACRUS]

 

Already 78 / 67 here 

[jm1220]

Some good swells coming in a few days anyway. Won’t be like Erin because a smaller storm but Humberto should produce some decent ones since it’s forecast to get to Cat 4.