The broad circulation of what was once Tropical Cyclone Henri spun across eastern New York on Monday, August 23, 2021, producing additional moderate to locally heavy rainfall with Greene County being the hardest hit. 50 inches across much of Greene County.
Every event with a place to put it. Tap one for its entry below.
Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.
The episode as NWS ALY wrote it up.
The broad circulation of what was once Tropical Cyclone Henri spun across eastern New York on Monday, August 23, 2021, producing additional moderate to locally heavy rainfall with Greene County being the hardest hit. Storm total rainfall from Henri spanning August 22nd to 23rd ranged between 4.00 to 7.50 inches across much of Greene County. This additional rainfall on the 23rd led to some incidents of flash flooding across the county.
Greene County was one of the several counties that Governor Andrew Cuomo declared a State of Emergency prior to Henri's arrival. President Joe Biden later approved a pre-landfall disaster declaration.
The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS Albany, NY wrote its last area forecast discussion before the first event at Aug 23, 10:17 AM EST, 1 hour 23 minutes earlier.
AREA FORECAST DISCUSSION National Weather Service Albany NY 1117 AM EDT Mon Aug 23 2021 && .SYNOPSIS... Additional showers, associated with Tropical Depression Henri, will continue through the afternoon hours today before coming to an end later this evening. Some showers could produce heavy downpours. In the wake of Tropical Depression Henri, very warm to hot and humid conditions is expected to develop through Thursday. Showers and thunderstorms are possible on Thursday ahead of a cold front. The cold front is expected to pass through the area on Friday bringing a noticeably cooler and drier airmass into the region Friday night and Saturday. && .NEAR TERM /THROUGH TONIGHT/... **Flood Watch continues for Litchfield, Berkshire, Greene, Columbia, Ulster, Dutchess, and Windham counties till this evening** .Update...As of 1100 AM EDT, rainfall associated with Henri is continuing across the southern half of our CWA this morning. The center of circulation of Henri looks to be located over southern Ulster and Dutchess counties at this time. Over the next several hours, the remnants of Henri are expected to gradually drift eastward. Drier air is getting wrapped into the center of the low per GOES 16 water vapor imagery, which is why coverage of showers has diminished over portions of Ulster and Dutchess counties over the past hour or so. However, moist southerly flow ahead of the surface low combined with forcing for ascent from the upper low will lead to rain, possibly heavy at times, continuing for the next several hours mainly for areas south and east of Albany. As the low moves eastward, the band of moderate to heavy rainfall looks to pivot over the Eastern Catskill, which is where some the heaviest additional amounts of 1-2" will be possible through the afternoon. This area, along with portions of the Mid Hudson Valley and Litchfield County, has already seen around an inch of rain over the past 3 hours with over 1.5" in the past 6 hours, so will continue to monitor this area in particular for any flooding concerns as we head into the afternoon. Main change with this update was to increase PoPs through the afternoon, especially for southern areas. Also made some slight tweaks to temperatures, dew points, wind, and sky cover to reflect current trends, but otherwise previous forecast looks to be in relatively good shape. Previous discussion below goes into more detail... .Previous [645 AM EDT] The rain shield associated with Tropical Depression Henri's pivoting around on the eastern side of the storm. This includes a band of moderate to heavy rain in the Poughkeepsie area (Ulster/Dutchess counties). Have issued a Flood Advisory for Dutchess County as a result. Expect for showers, moderate to heavy at times, to increase in coverage over the southern portions of the area eastward into western New England. Have made adjustments to PoPs, Wx, temperature, and dewpoint grids to reflect current observations. Rest of forecast remains on track. See previous discussion below. As of 4:00 AM EDT, the center of Tropical Depression Henri was located over southern New York with the rain shield pivoting from eastern PA and northern NJ into southern New York (including the eastern Catskills). Additional showers associated with Tropical Depression Henri are expected to continue through much of the day today as the rain shield continues to pivot over the eastern Catskills and mid-Hudson Valley into New England. So far, 1 to 4 inches of rain has fallen over areas south of I-90 with the heaviest concentration of QPF located over Greene County near Tannersville. According to current guidance, an additional 1-2 inches of rainfall is expected south of I-90 and over western New England with lighter amounts along and north of I-90 today as the storm departs to our northeast. That said, PoPs will decrease in coverage from southwest to northeast this evening as Henri departs. Limited incoming solar radiation from the extensive cloud deck associated with Henri will help to hold high temperatures in the mid to upper 70s (upper 60s to lower 70s higher elevations). Tonight, warm and muggy conditions will continue under mostly cloudy skies. Overnight low temperatures will hold in the mid to upper 60s (lower 60s higher elevations). && .SHORT TERM /TUESDAY THROUGH WEDNESDAY/... Dry and tranquil weather conditions return to the area on Tuesday as a 1016-1020 hpa high pressure system builds in from the south. Skies will show improvements throughout the day. This will allow for more solar radiation than the day before, thus allowing for high temperatures into the mid to upper 80s along the river valleys (upper 70s to lower 80s higher elevations). Tuesday night, light winds, clear to mostly clear skies, and abundant low level moisture will aid i the development of fog across the area. Conditions will also be warm and muggy with overnight lows in the lower to mid 60s along the river valleys (upper 50s higher elevations). On Wednesday, the H500 pattern becomes zonal. A mid-upper perturbation will track along this zonal flow aloft ahead of a storm system over the north-central U.S./Ontario Canada. Instability levels and moisture values do creep up over over the course of the day. However, a 1020 hpa surface high will still be over the area. That said, most areas should remain dry on Wednesday, however, given the increasing moisture and instability values, there could be an isolated shower or thunderstorm that develops during the evening hours especially west of the Hudson Valley. High temperatures on Wednesday will be very warm to hot with values in the upper 80s to near 90 (mid-Hudson valley). Given the humidity that will be in place, heat indices will approach Heat Advisory levels Wednesday afternoon. Trends on this will be closely monitored later today. && .LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/... We begin the long term period Wednesday night into Thursday with upper level ridging and southwest winds aloft ushering in a very warm and humid air mass into eastern NY and western New England. With 850hPa isotherms and PWATs nearly 2 standard deviations above normal on Thursday, areas in the Hudson Valley could reach heat advisory criteria (heat index values 95F or greater) due to the combination of high temperatures reaching into the mid to upper 80s (near 90 in the mid-Hudson valley) and dew points in the upper 60s to low 70s. Upper level ridging shifts into New England during the day on Thursday with a few shortwave impulses and a weak surface trough moving into eastern NY behind it during the afternoon hours. Guidance is in generally good agreement that these features will result in some scattered afternoon showers and thunderstorms. With such a warm and humid air mass in place, instability values could become rather high with potential for heavy downpours given high PWATs in place. The stronger parent shortwave will then be tracking well to our north through northern Quebec on Friday with its trailing cold front passing through the Northeast. The ECWMF and CMC are in generally good agreement that the parent trough is displaced well to our north with a rather moisture starved cold front. This is likely why both models suggest the front pushes through with little in the way to QPF. The GFS, on the other hand, shows the parent trough tracking further south through Quebec and between the strong forcing and increased moisture along the boundary, it suggests there could be more appreciable shower/storm activity. We decided to lean closer to the ECMWF and CMC blend and only placed slight chance POPs for Friday. Otherwise, temperatures on Friday should be a few degrees cooler compared to the previous few days but still seasonably warm and humid, especially south of I-90. A conspicuous air mass change is then expected Friday night into Saturday as a strong Canadian high sinks southward and builds into northern New England. While there should be a period of relief from the heat and humidity, the boundary from Friday looks to stall in the mid-Atlantic. There are some discrepancies on exactly how far south the boundary stalls which will dictate if the entire region experiences a break from the heat/humidity or if it's just northern zones. For now, thinking that the Canadian high should provide some relief Friday night with dew points dropping into the 50s but the humid and warm air mass may not be far away on Saturday. We show a mainly dry forecast for Saturday but increased POPs Saturday night into Sunday as the stalled boundary retreats back northward. && .AVIATION /15Z MONDAY THROUGH FRIDAY/... MVFR conditions will persist at most of the terminals through the end of the TAF period as an upper level disturbances absorbs what is left of tropical cyclone Henri and tracks through eastern NY and western New England today. POU and PSF have the best chance to experience periods of rain between 15 UTC to 21 UTC during the peak heating of the day. During any steadier periods of rain, ceilings and visibilities may drop to IFR, if rain is especially heavy. Due to low confidence in the exact placement and duration, we chosen not to drop below MVFR ceilings/visibilities. ALB and especially GFL may be just north of where the more organized rain from the remnants of Henri but it may still experience some scattered showers and even some thunderstorms if there are any breaks of sun during peak heating hours (15 UTC to 21 UTC Monday). During any heavier periods of rain or storms, ceilings and vsibilities may drop to IFR but again due to low confidence on exact placement of the showers, we used a TEMPO group to highlight the potential for precipitation. Otherwise, expecting MVFR ceilings tonight to gradually improve to low end VFR after 15 UTC. During any periods of showers/storms, CIGS and VIS may quickly drop back to MVFR. After 00 UTC, the remnants of Henri exit into New England with clearing skies expected thereafter. Due to plenty of low level moisture in place, fog and low stratus may quickly develop resulting in MVFR or even IFR CIGS/VIS, especially at POU and PSF where more rainfall is expected during the daytime. East to southeast winds the rest of tonight will remain sustained between 5 and 10kts before shifting to the northeast and north this afternoon as Henri exits into New England. After 00 - 03 UTC, drier air moves into the region and winds should shift to the northwest and weaken below 5kts. Outlook... Tuesday Night: No Operational Impact. Patchy FG. Wednesday: No Operational Impact. Patchy FG. Wednesday Night: Low Operational Impact. Slight Chance of SHRA...TSRA. Thursday: Moderate Operational Impact. Chance of SHRA...TSRA. Thursday Night: Low Operational Impact. Slight Chance of SHRA. Friday: Low Operational Impact. Slight Chance of SHRA...TSRA. Friday Night: Low Operational Impact. NO SIG WX. Saturday: Low Operational Impact. Slight Chance of SHRA...TSRA. && .FIRE WEATHER... No fire weather concerns are expected over the next few days. Additional showers, associated with Tropical Depression Henri, will continue through the afternoon hours today before coming to an end later this evening. Some showers could produce heavy downpours. In the wake of Tropical Depression Henri, very warm to hot and humid conditions is expected to develop through Thursday. Showers and thunderstorms are possible on Thursday ahead of a cold front. The cold front is expected to pass through the area on Friday bringing a noticeably cooler and drier airmass into the region Friday night and Saturday. Minimum relative humidity values today will range from 80-100%. Tonight, relative humidity values will max out between 85-100%. During the day on Tuesday, minimum relative humidity values will range between 55-80%. Tuesday night, maximum relative humidity values will range between 80-100%. On Wednesday, minimum relative humidity values will range between 50-65%. Winds today will be northerly between 5-10 kts. Tonight, winds will subside to less than 5 kts out of the west-northwest. On Tuesday, winds will remain light out of the west-northwest at magnitudes up to 5 kts. Tuesday night, winds will become light and variable. On Wednesday, winds will shift out of the south-southwest at magnitudes of less than 5 kts. && .HYDROLOGY... Flash flooding and river flooding will continue to be the primary hydrological concerns in the near term or through the day today. As of 4:00 AM EDT, any where from 1-4 inches of rain have fallen approximately from Albany and points south with the heaviest concentrated over Greene County near Tannersville. As it stands, Farmington at New Boston, Housatonic River at Coltsville, Rondout Creek at Rosendale, Schoharie Creek at Prattsville, Schoharie Creek at Gilboa Bridge, and Williams River near Rockingham are all forecast to get near (just below or just above) minor flood stage. Housatonic at Falls Village and at Gaylordsville are expected to get into minor flood stage during the day today. Additional showers, some convective, are expected today as the storm departs. Given the high PWAT environment with values ranging between 1.75-2.00+ inches, some 1-3 STDEVS above normal, any shower that develops has the capability of producing localized flash flooding with rain rates in excess of 1 inch/hr. This is especially true for areas south of I-90 and across western New England. Flash flooding and river flooding threats decrease later this evening/tonight as the storm weakened and departs to our northeast. Dry weather returns on Tuesday allowing for river levels to recede. For details on specific area rivers and lakes, including observed and forecast river stages and lake elevations, please visit the Advanced Hydrologic Prediction Service /AHPS/ graphs on our website. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...Flood Watch until 8 PM EDT this evening for CTZ001-013. NY...Flood Watch until 8 PM EDT this evening for NYZ058>061-063>066. MA...Flood Watch until 8 PM EDT this evening for MAZ001-025. VT...Flood Watch until 8 PM EDT this evening for VTZ014-015. && UPDATE... SYNOPSIS...Evbuoma NEAR TERM...Evbuoma/Main SHORT TERM...Evbuoma LONG TERM...Speciale AVIATION...Speciale FIRE WEATHER...Evbuoma HYDROLOGY...Evbuoma
Hazardous Weather Outlook National Weather Service Albany NY 414 AM EDT Mon Aug 23 2021 CTZ001-013-MAZ001-025-NYZ058>061-063>066-VTZ014-015-241100- Northern Litchfield-Southern Litchfield-Northern Berkshire- Southern Berkshire-Western Greene-Eastern Greene-Western Columbia- Eastern Columbia-Western Ulster-Eastern Ulster-Western Dutchess- Eastern Dutchess-Western Windham-Eastern Windham- 414 AM EDT Mon Aug 23 2021 ...FLOOD WATCH IN EFFECT THROUGH THIS EVENING... This Hazardous Weather Outlook is for northwestern Connecticut, western Massachusetts, the eastern Catskills, mid Hudson Valley, and central and southern Taconics of eastern New York and Windham County in southern Vermont. .DAY ONE...Today and tonight. Please listen to NOAA Weather Radio or go to weather.gov on the Internet for more information about the following hazards. Flood Watch. .DAYS TWO THROUGH SEVEN...Tuesday through Sunday. Heat indices may reach advisory levels in the mid and upper 90s in the Hudson Valley area of eastern New York Wednesday and Thursday. There is a chance of thunderstorms Thursday afternoon into the evening. .SPOTTER INFORMATION STATEMENT... Weather spotters are encouraged to relay rainfall amounts and flooding to the National Weather Service in Albany New York, while following local, state and CDC guidelines. NYZ032-033-038>043-047>054-082>084-VTZ013-241100- Northern Herkimer-Hamilton-Southern Herkimer-Southern Fulton- Montgomery-Northern Saratoga-Northern Warren-Northern Washington- Schoharie-Western Schenectady-Eastern Schenectady-Southern Saratoga- Western Albany-Eastern Albany-Western Rensselaer-Eastern Rensselaer- Northern Fulton-Southeast Warren-Southern Washington-Bennington- 414 AM EDT Mon Aug 23 2021 This Hazardous Weather Outlook is for the southern Adirondacks, Mohawk Valley, Greater Capital Region, northern Taconics, Schoharie Valley, Helderbergs and the Lake George northern Saratoga Region of eastern New York and Bennington County southern Vermont. .DAY ONE...Today and tonight. Intermittent showers and isolated thunderstorms may be heavy enough to cause rises on area rivers and streams, as well as some ponding of water on roadways and poor drainage flooding of low lying areas. .DAYS TWO THROUGH SEVEN...Tuesday through Sunday. Heat indices may reach advisory levels in the mid and upper 90s in the Hudson Valley area of eastern New York Wednesday and Thursday. There is a chance of thunderstorms Thursday afternoon into the evening. .SPOTTER INFORMATION STATEMENT... Spotter activation is not expected at this time.
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE ALBANY NY
931 AM EDT MON AUG 23 2021
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0725 AM HEAVY RAIN PITTSFIELD 42.42N 73.23W
08/23/2021 M1.93 INCH BERKSHIRE MA WEATHERNET6
WEATHERNET6
0728 AM HEAVY RAIN CAIRO 42.31N 73.99W
08/23/2021 M2.25 INCH GREENE NY WEATHERNET6
WEATHERNET6
0733 AM HEAVY RAIN GERMANTOWN 42.15N 73.87W
08/23/2021 M2.62 INCH COLUMBIA NY WEATHERNET6
WEATHERNET6
0750 AM HEAVY RAIN WEST KILL 42.20N 74.33W
08/23/2021 M2.95 INCH GREENE NY WEATHERNET6
WEATHERNET6
0806 AM HEAVY RAIN JEFFERSON 42.49N 74.60W
08/23/2021 M1.10 INCH SCHOHARIE NY WEATHERNET6
WEATHERNET6
0808 AM HEAVY RAIN JEFFERSON 42.46N 74.58W
08/23/2021 M2.00 INCH SCHOHARIE NY WEATHERNET6
WEATHERNET6
0809 AM HEAVY RAIN POUGHKEEPSIE 41.70N 73.92W
08/23/2021 M3.90 INCH DUTCHESS NY TRAINED SPOTTER
0810 AM HEAVY RAIN PHOENICIA 42.07N 74.34W
08/23/2021 M2.47 INCH ULSTER NY WEATHERNET6
WEATHERNET6
0829 AM HEAVY RAIN OLIVEBRIDGE 41.96N 74.20W
08/23/2021 M3.10 INCH ULSTER NY WEATHERNET6
WEATHERNET6
0831 AM HEAVY RAIN GREENVILLE CENTER 42.41N 74.01W
08/23/2021 M2.25 INCH GREENE NY WEATHERNET6
WEATHERNET6
0835 AM HEAVY RAIN TAGHKANIC 42.09N 73.68W
08/23/2021 M1.20 INCH COLUMBIA NY WEATHERNET6
WEATHERNET6
0840 AM HEAVY RAIN 2 SE TIVOLI 42.04N 73.89W
08/23/2021 M1.50 INCH DUTCHESS NY TRAINED SPOTTER
0855 AM HEAVY RAIN 1 WSW RED OAKS MILL 41.65N 73.90W
08/23/2021 M2.76 INCH DUTCHESS NY TRAINED SPOTTER
0855 AM HEAVY RAIN 2 SSE POUGHKEEPSIE 41.67N 73.91W
08/23/2021 M3.74 INCH DUTCHESS NY TRAINED SPOTTER
0921 AM HEAVY RAIN LIVINGSTON 42.13N 73.79W
08/23/2021 M1.62 INCH COLUMBIA NY WEATHERNET6
WEATHERNET6
&&
EVENT NUMBER ALY2104045
EVENT NUMBER ALY2104046
EVENT NUMBER ALY2104047
EVENT NUMBER ALY2104048
EVENT NUMBER ALY2104049
EVENT NUMBER ALY2104050
EVENT NUMBER ALY2104051
EVENT NUMBER ALY2104052
EVENT NUMBER ALY2104053
EVENT NUMBER ALY2104054
EVENT NUMBER ALY2104055
EVENT NUMBER ALY2104056
EVENT NUMBER ALY2104057
EVENT NUMBER ALY2104058
EVENT NUMBER ALY2104059
DBTPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE ALBANY NY
932 AM EDT MON AUG 23 2021
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0900 AM HEAVY RAIN 6 WSW KINGSTON 41.90N 74.11W
08/23/2021 M3.20 INCH ULSTER NY COCORAHS
&&
EVENT NUMBER ALY2104060
DBTPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE ALBANY NY
1037 AM EDT MON AUG 23 2021
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
1030 AM HEAVY RAIN WOODBURY CENTER 41.55N 73.21W
08/23/2021 M2.04 INCH LITCHFIELD CT TRAINED SPOTTER
STORM TOTAL. 1.07 SINCE MIDNIGHT.
&&
EVENT NUMBER ALY2104061
DBTPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE ALBANY NY
1038 AM EDT MON AUG 23 2021
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0800 AM HEAVY RAIN 2 SW NORFOLK 41.97N 73.23W
08/23/2021 M2.39 INCH LITCHFIELD CT CO-OP OBSERVER
&&
EVENT NUMBER ALY2104063
DBTPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE ALBANY NY
1039 AM EDT MON AUG 23 2021
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0800 AM HEAVY RAIN 2 SE COLEBROOK 41.98N 73.06W
08/23/2021 M2.24 INCH LITCHFIELD CT TRAINED SPOTTER
&&
EVENT NUMBER ALY2104064
DBTPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE ALBANY NY
1040 AM EDT MON AUG 23 2021
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
1030 AM HEAVY RAIN 3 S SANDISFIELD 42.07N 73.14W
08/23/2021 M2.59 INCH BERKSHIRE MA TRAINED SPOTTER
&&
EVENT NUMBER ALY2104065
DBTThe Albany radar (KENX), 32 km away, was scanning. The volume nearest the first event began at 16:41 UTC.
2 flash flood, 1 flood. Local standard time, as filed.
County Route 385 was closed between Bailey Street and Lawrence Avenue under a railroad viaduct due to flooding. This is a typical flood prone spot.
Paul Saxe Road was closed at Mountain Turnpike Road in the Town of Catskill due to flash flooding.
Mountain Avenue in the Hamlet of Cairo was closed due to flash flooding.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in New York in 2021Every state in 2021This day in weather historyWarnings in New York, August 2021
NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 978603, 978601, 978602.