A weak disturbance moving through the upper atmosphere across southern New York combined with an unusually warm and moist airmass to produce several rounds of scattered showers and thunderstorms over Chemung county. A very localized total of 2 to 3 inches of rain fell just to the west of Elmira, NY.
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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 BGM wrote it up.
A weak disturbance moving through the upper atmosphere across southern New York combined with an unusually warm and moist airmass to produce several rounds of scattered showers and thunderstorms over Chemung county. A very localized total of 2 to 3 inches of rain fell just to the west of Elmira, NY. The runoff from this heavy rain overwhelmed several small streams near the Horseheads exchange along I-86. The Interstate was severely flooded and remained closed until the morning of the 29th.
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 Binghamton, NY wrote its last area forecast discussion before the first event at Aug 28, 8:51 AM EST, 2 hours 24 minutes earlier.
Area Forecast Discussion National Weather Service Binghamton NY 951 AM EDT Mon Aug 28 2023 .SYNOPSIS... Unsettled weather returns on Monday with scattered showers and thunderstorms possible. A stronger front will bring additional showers and thunderstorms to the area on Tuesday, with some lingering lake effect rain showers on Wednesday. High pressure will then bring dry and cooler weather through the end of the week. && .NEAR TERM /THROUGH TUESDAY/... 945 AM Update... It has been a challenging forecast this morning. Fog drifted west from Oneida County and into Onondaga County. That has begun to clear out and visibilities have greatly improved. Showers and isolated thunderstorms have moved into the Southern Tier. Guidance has struggled with this initial round of showers, so if the current trend continues, showers will likely move further north more quickly than expected. Because of this, PoPs were expanded northward throughout the morning hours. Thunder chances were reduced slightly heading into the early afternoon hours as increasing cloud cover will keep conditions cool and limit instability. For the rest of the forecast, some minor updates were needed to temps and dewpts to better match the latest obs. 600 AM Update... Manually updated Pops using Radar to include showers that are moving in over Bradford county. Also updated temperatures and dewpoints with a blend of current observations and NBM. Otherwise the previous forecast remains on track. 330 AM Update... Surge of moisture moves northward into our region early this morning increasing cloud cover and eventually bringing in scattered rain showers and a few possible thunderstorms. Showers will begin shortly after sunrise for NEPA moving into CNY by early afternoon. Instability features are lacking in this setup therefore any afternoon thunderstorms that do develop will most likely be isolated and weak. Otherwise partly sunny to mostly cloudy skies are expected with highs mainly in the 70s. Similar conditions continue into the overnight hours with some scattered showers and perhaps an evening thunderstorm. Best chances of seeing nocturnal showers is north of the NY Thruway corridor. Otherwise most of the night will be covered by a blanket of clouds keeping temperatures mild with lows in the 60s. A shallow upper level trough west of our region continues to advect more moisture in from the south on Tuesday. This set up triggers more scattered showers and thunderstorms in the afternoon. Instability parameters are modest with GFS CAPE values up to 320 J/Kg combined with 30 knots of 0-6 km bulk shear. Overall conditions are not too unstable, wind gusts would be the main concern if a stronger storm is able to develop. && .SHORT TERM /TUESDAY NIGHT THROUGH WEDNESDAY NIGHT/... 330 AM Update This period remains unsettled with several shortwaves and a deeper upper level trough moving through the area. Model guidance is showing a weak wave of low pressure bringing an area of enhanced moisture and some instability north/northeast across at least the southeast portion of our CWA Tuesday night. PWATs increase to around 1.8 inches over the Wyoming Valley, Poconos and southern Catskills overnight. Short range guidance and the few CAMs that do go out far enough in time to cover Tuesday night are not yet in great agreement on the exact timing and track of this rain/thunderstorm complex. For now, stuck close to the ensemble NBM guidance for PoPs and WPC for QPF. This gave likely PoPs for rain showers and chances for t'storms, with rainfall amounts of 0.50 to 1.00 inch along and southeast of a Scranton--Honesdale--Monticello line...with much lighter rainfall amounts further north and west. Otherwise, Tuesday night will be mostly cloudy and muggy with lows in the 60s areawide. The latest deterministic and ensemble guidance has slowed down the passage of the main upper level trough on Wednesday...with it now crossing our CWA early Wednesday afternoon. Out ahead of the trough axis and surface front, it will remain partly to mostly cloudy, with scattered rain showers and humid conditions through midday Wednesday. The slower frontal passage allows temperatures to reach the upper 60s to mid-70s Wednesday, which is a few degrees warmer than the previous forecast. After the frontal passage in the afternoon, winds turn northwest and 850mb temperatures fall to around +9C late in the day. This may be just cool enough to elicit a weak lake response off of Ontario, with some additional pop up showers also forming on the backside of the 700/500mb trough. With the later timing, lingered more clouds and isolated showers into at least the first half of Wednesday night. Then, drier air should mix out the clouds as heights rise and a surface high begins to build in from the west. North-northwest winds remain breezy Wednesday afternoon into Wednesday night, between 8-15 mph with gusts up to 25 mph. Overnight lows are cool, dipping down into the upper 40s to mid-50s. && .LONG TERM /THURSDAY THROUGH SUNDAY/... 345 AM Update A fast moving upper level trough will be swinging east across northern New England Thursday morning, and off the East Coast later in the day. Very dry air in the mid level of the atmosphere, will combine with an incoming surface high to keep our weather dry. The remnants of Idalia will remain well off to the south, drifting east off the North Carolina coast, with no impact here. There remains some question on if there will be any lingering lake effect clouds in the morning, on the northerly flow as the forecast soundings do show a thin saturated layer below 850mb...either way, this quickly mixes out with ample sunshine much of the day. Breezy and cool north winds continue over the area at 8 to 15 mph and 850mb temperatures hover around +7 or +8C through the day. However, with plenty of sun expected it looks to still warm up into the low to mid-70s for daytime highs. The upcoming Labor Day Weekend (Friday through Monday) will feature absolutely spectacular late summer weather across the entire forecast area. Conditions are forecast to be perfect for camping, boating, swimming or any other outdoor activities. High pressure is directly overhead on Friday, with sunny skies and warm afternoon highs in the upper 70s to lower 80s, along with light southerly winds. Zonal westerly flow returns on Saturday and Sunday as a very weak wave rolls across the Northeast late Saturday or Saturday night. Kept the official forecast close to the NBM ensemble guidance, which keeps us dry with just some scattered clouds around. More afternoon cumulus clouds develop on Sunday, with some instability around, but overall still mostly sunny conditions expected. Gradual warming trend continues over the weekend; with morning lows in the 50s to low 60s and highs reaching 80 to 85 in most locations. Upper level ridge reamplifies over the area for Labor Day, bringing more mostly sunny, dry and warm weather to the region...highs will reach the low to mid-80s. && .AVIATION /14Z MONDAY THROUGH FRIDAY/... LIFR fog at ELM from 12-14Z, then remains MVFR with showers moving through. Restrictions are expected to improve to VFR at 21Z. Guidance hints at IFR conditions returning tonight at ELM/RME/ITH, confidence is low on the intensity at this time. Showers will move through SYR and RME in the afternoon but VFR conditions are expected to persist. Although guidance hints at low VFR ceilings so it is possible that ceilings fall to MVFR as well. Confidence on this was not high enough to include in the TAF. SYR is expected to remain VFR throughout the whole period. ITH/BGM/AVP start off at VFR conditions before briefly falling to MVFR as showers move through. Then restrictions are expected to improve back to VFR at these terminals. Southerly winds under 10 knots are expected during this period. Outlook... Monday night through Tuesday...Mainly VFR, although brief restrictions are possible in scattered showers and possibly a thunderstorm. Wednesday...Mainly VFR for KAVP and KELM. However, lake effect clouds and rain showers may bring occasional restrictions to KRME, KSYR, KITH, and/or KBGM. Thursday through Friday...Mainly VFR. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...None. NY...None. && SYNOPSIS...BJG NEAR TERM...BTL/ES SHORT TERM...MJM LONG TERM...MJM AVIATION...ES
Hazardous Weather Outlook National Weather Service Binghamton NY 352 AM EDT Mon Aug 28 2023 NYZ009-015>018-022>025-036-037-044>046-055>057-062-PAZ038>040-043- 044-047-048-072-290800- Northern Oneida-Yates-Seneca-Southern Cayuga-Onondaga-Steuben- Schuyler-Chemung-Tompkins-Madison-Southern Oneida-Cortland-Chenango- Otsego-Tioga-Broome-Delaware-Sullivan-Bradford-Susquehanna- Northern Wayne-Wyoming-Lackawanna-Luzerne-Pike-Southern Wayne- 352 AM EDT Mon Aug 28 2023 This Hazardous Weather Outlook is for central New York and northeast Pennsylvania. .DAY ONE...Today and tonight. No hazardous weather is expected at this time. .DAYS TWO THROUGH SEVEN...Tuesday through Sunday. No hazardous weather is expected at this time. .SPOTTER INFORMATION STATEMENT... Spotter activation is not expected at this time.
Preliminary Local Storm Report
National Weather Service Binghamton NY
1044 AM EDT Mon Aug 28 2023
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
1043 AM Flood Elmira 42.09N 76.81W
08/28/2023 Chemung NY Trained Spotter
A few inches of water at several
intersections.
&&The Binghamton radar (KBGM), 68 km away, was scanning. The volume nearest the first event began at 16:16 UTC.
1 flash flood. Local standard time, as filed.
Water from two small creeks rushed rapidly off of a nearby hill and significantly flooded both lanes of I-86 near the Horseheads interchange. The interstate remained closed until the following morning.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in New York in 2023Every state in 2023This day in weather historyWarnings in New York, August 2023
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: 1131178.