An area of moderate to heavy rain, with embedded thunderstorms, moved through Central New York causing areas of common urban flooding and ponding of water in a few locations.
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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.
An area of moderate to heavy rain, with embedded thunderstorms, moved through Central New York causing areas of common urban flooding and ponding of water in a few locations.
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 Apr 20, 7:33 PM EST, 2 hours 42 minutes earlier.
Area Forecast Discussion National Weather Service Binghamton NY 833 PM EDT Thu Apr 20 2017 .SYNOPSIS... Showers and storms expected tonight will taper off Friday morning from west to east. Cool high pressure will dominate the region this weekend before a warm up arrives next week along with additional chances for showers and storms by the middle of the week. && .NEAR TERM /THROUGH FRIDAY/... 830 PM update... The first line of storms this evening produced wind gusts between 25 and 40 mph and dropped around a half-inch of rain. The next wave of thunderstorms, currently over Western New York, is on schedule to arrive in our western forecast area in the next 1 to 2 hours. The radar returns are less impressive than when the thunderstorms first came out of Canada, and the trend in intensity appears downward. We will, however, continue to closely monitor this area of storms. 400 pm update... Main concern in the near term remains focused around the incoming showers and storms this evening and tonight with the potential for a few strong storms producing gusty winds, small hail and heavy downpours. The precipitation will taper off Friday morning with quiet weather Friday afternoon. Strengthening upper trough over the wrn Great Lakes and associated sfc low near MI this afternoon will be driving force behind the potential for showers and storms today through tonight. A warm front extending ewd from the sfc low into srn NY/nrn PA will continue to lift nwd as strong WAA and moisture transport from the south push into the area. The unstable air mass further to the south across wrn PA this afternoon will attempt to move into central NY/ne PA this evening, but the presence of a cool stable layer at the surface will allow most of the instability to become elevated. There may be a brief period where sfc based convection to the south makes its way into far srn NY and portions of ne PA. Sfc based CAPE values 500- 1000 J/kg and increasing deep layer moisture will produce a few storms to the south. Downdraft CAPE values around 200-500 J/kg and steep low level lapse rates will produce the potential for gusty winds. There is also the threat for small hail and brief heavy rain this afternoon. However, the overall trend will be to transition from sfc based to more elevated convection this evening and tonight as the warm layer lifts and modifies mid level thermal/moisture profiles. The main batch of showers and storms will arrive later this evening ahead of a ewd progressing cold front. Much of the mid levels will become well mixed and slightly unstable with around 300-600 J/kg of 850-500mb CAPE. The main concern tonight will likely be the threat of heavy downpours and localized flooding. PWATs 1-1.3 inches within an unstable deep layer will make it favorable for a quick 0.5 to 1 inch of rain in a relatively short period of time. One thing to watch will be the nwrd extent of the warm front. If the front doesn't lift far enough north, there may be quasi-training storms along and south of the front through central NY with a continuous influx of deep moisture from the south being focused along this boundary. This threat will likely be mitigated the further north the front lifts. The progressive nature of the entire system will also be a factor in limiting the threat for widespread hydro issues. Rain showers will taper off Friday morning as the system exits to the east. Winds will shift to the west/sw through the day with skies attempting to clear out later in the day. Temperatures will warm into the upper 50s and lower 60s in central NY...and into the upper 60s and lower 70s in ne PA. && .SHORT TERM /FRIDAY NIGHT THROUGH SATURDAY NIGHT/... 311 PM EDT Update... By 00Z Sat a mid-lvl trough will start to pass through the region and the sfc cold front should be mostly if not all the way through the area. Mid and uppr lvl dry advection will continue to be present in the wake of this boundary, thus most of the area will continue to remain dry through the night. Temps will steadily fall through the night and sfc temps are expected to fall into the uppr 30s to low 40s by sunrise. By 12Z Sat, the mid-lvl trough axis will shift east of the region and NW flow will prevail over central NY and northeast PA. Low-lvl moisture however will remain plentiful and with the NW flow, upslope there will be a chance for an isolated shower through the day on Saturday over central NY. Temps during the afternoon will rebound somewhat into the uppr 40s into the low 50s across central NY, and low to mid 50s across NEAP. Saturday evening the mid-lvl ridge will move into the region from the west and uppr lvl trough will start to swing through the state of NY. As this starts to happen a storm system from the south tries to sneak into far NEPA to bring a round of showers Sat night, but however confidence is fairly low as with each new guidance this system continues to shift further to the east. Due to the NW flow (CAA), sfc temps will fall into the mid 30s to low 40s Sat night/Sun morning. && .LONG TERM /SUNDAY THROUGH THURSDAY/... 311 PM EDT Update... The system that may impact the region on Saturday, may impact the region for a brief period Monday morning as sfc high pressure quickly builds into the region and near zonal flow develops over the region aloft. High pressure will remain over the region through Tuesday night keep the region dry. The next system to impact our region is expected to move into our area as early as next Wed. There are a lot of discrepancies within the guidance starting Wednesday, thus decided to go on the conservative side and keep chances for precip low for Wed and Thurs. During this period there will be a warming trend and sfc temps are expected to rise above the seasonal norm. && .AVIATION /01Z FRIDAY THROUGH TUESDAY/... A band of widespread showers and embedded thunderstorms are moving through the NYS terminals at this time with widespread MVFR and brief IFR conditions. Another batch is expected later this evening with the surface cold front. This activity will move through between 03Z-08Z with widespread showers again and embedded thunderstorms. Flight category will range from alternate required to IFR. Once this passes light showers and lowering ceiling will result in widespread IFR conditions. Slow improvement is expected Thursday morning with VFR conditions during the afternoon. Southeast winds around 10 knots shifting to the south overnight then southwest by daybreak. Westerly winds on Thursday at 10-12 knots. Outlook... Friday night and Saturday...VFR. Sunday...Possibly restrictions in SHRA from KELM, KBGM to KAVP. Monday - Tuesday...VFR. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...None. NY...None. && SYNOPSIS...BJT NEAR TERM...BJT/DJP/PCF SHORT TERM...KAH LONG TERM...KAH AVIATION...RRM
Hazardous Weather Outlook National Weather Service Binghamton NY 319 PM EDT Thu Apr 20 2017 NYZ009-015>018-022>025-036-037-044>046-055>057-062-PAZ038>040-043- 044-047-048-072-211930- 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- 319 PM EDT Thu Apr 20 2017 This Hazardous Weather Outlook is for central New York and northeast Pennsylvania. .DAY ONE...This Afternoon and Tonight. Showers and thunderstorms are expected to move into the region this evening ahead of an approaching cold front. There is the risk a few of these storms could become severe with strong winds being the main threat. Storms will also be capable of bringing heavy rainfall with local urban and small stream flooding possible. .DAYS TWO THROUGH SEVEN...Friday through Wednesday. Hazardous weather is not expected at this time. .SPOTTER INFORMATION STATEMENT... Spotter activation may be needed.
Special Weather Statement
National Weather Service Binghamton NY
650 PM EDT THU APR 20 2017
PAZ038-202330-
Bradford PA-
650 PM EDT THU APR 20 2017
...STRONG THUNDERSTORM WILL AFFECT...CENTRAL BRADFORD COUNTY UNTIL
730 PM EDT...
At 650 PM EDT, Doppler radar was tracking a strong thunderstorm near
Le Roy, or 8 miles east of Canton, moving northeast at 45 mph.
Winds in excess of 40 mph will be possible with this storm.
Locations impacted include...
Towanda, Canton, West Franklin, Wysox, Orwell, North Towanda,
Herrick, Wyalusing, Monroe and Rome.
LAT...LON 4159 7680 4166 7685 4196 7617 4190 7613
4168 7612 4156 7652
TIME...MOT...LOC 2250Z 243DEG 37KT 4162 7671
DJPSpecial Weather Statement
National Weather Service Binghamton NY
707 PM EDT THU APR 20 2017
NYZ055-056-PAZ038-039-043-202345-
Tioga NY-Broome NY-Wyoming PA-Susquehanna PA-Bradford PA-
707 PM EDT THU APR 20 2017
...A LINE OF STRONG THUNDERSTORMS WILL AFFECT...SOUTHWESTERN
BROOME...TIOGA...WESTERN SUSQUEHANNA...NORTHEASTERN BRADFORD AND
NORTH CENTRAL WYOMING COUNTIES UNTIL 745 PM EDT...
At 707 PM EDT, Doppler radar was tracking strong thunderstorms along
a line extending from near Spencer to near East Smithfield. Movement
was east at 35 mph.
Winds in excess of 40 mph will be possible with these storms.
Locations impacted include...
Binghamton, Vestal, Johnson City, Endicott, Barton, Kirkwood, Sayre,
Conklin, Waverly and Rush.
LAT...LON 4182 7669 4200 7660 4200 7656 4201 7656
4205 7654 4208 7655 4226 7646 4214 7571
4157 7602
TIME...MOT...LOC 2307Z 289DEG 32KT 4218 7642 4187 7658
DJPSpecial Weather Statement
National Weather Service Binghamton NY
739 PM EDT THU APR 20 2017
NYZ045-055-056-PAZ039-040-043-044-210030-
Chenango NY-Tioga NY-Broome NY-Wyoming PA-Susquehanna PA-
Northern Wayne PA-Lackawanna PA-
739 PM EDT THU APR 20 2017
...A LINE OF STRONG THUNDERSTORMS WILL AFFECT...BROOME...SOUTHEASTERN
TIOGA...SOUTHERN CHENANGO...SUSQUEHANNA...NORTH CENTRAL LACKAWANNA...
NORTHERN WAYNE AND NORTHEASTERN WYOMING COUNTIES UNTIL 830 PM EDT...
At 739 PM EDT, Doppler radar was tracking strong thunderstorms along
a line extending from near Union Center to near Springville. Movement
was east at 45 mph.
Winds in excess of 40 mph will be possible with these storms.
Locations impacted include...
Binghamton, Vestal, Johnson City, Endicott, Kirkwood, Conklin, Maine,
Rush, Jackson and Clifford.
LAT...LON 4167 7509 4164 7546 4163 7546 4157 7601
4219 7621 4242 7538 4239 7540 4236 7539
4232 7542 4204 7542 4200 7539 4199 7534
4195 7531 4195 7529 4186 7526 4187 7517
4185 7515
TIME...MOT...LOC 2339Z 255DEG 39KT 4214 7611 4166 7595
DJPThe national radar mosaic for the moment the first event began.
4 flood. Local standard time, as filed.
Ponded water was reported on West Lake Road.
Water was reported on several roads in Middlesex.
Water was reported over several town and village streets in, and near Moravia.
Water was reported to be ponding in several locations of Rockefeller Road.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in New York in 2017Every state in 2017This day in weather historyWarnings in New York, April 2017
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: 696337, 696339, 696345, 696344.