On Friday, May 15, 2020, an intense line of thunderstorms quickly developed near Lake Ontario and raced eastward across eastern New York, reaching southern Vermont by around 6:30 pm. The storms produced several reports of wind damage across southern Vermont.
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.
On Friday, May 15, 2020, an intense line of thunderstorms quickly developed near Lake Ontario and raced eastward across eastern New York, reaching southern Vermont by around 6:30 pm. The storms produced several reports of wind damage across southern Vermont. Statewide, there were nearly 4,500 customers who lost power, most of which were concentrated in southern Vermont.
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 May 15, 3:55 PM EST, 1 hour 31 minutes earlier.
AREA FORECAST DISCUSSION National Weather Service Albany NY 455 PM EDT Fri May 15 2020 .SYNOPSIS... A warm front moving across eastern New York and western New England this afternoon will usher in a warm and more humid air mass. As a cold front pushes into the region this evening, a line of strong to potentially severe thunderstorms will impact the region with damaging winds the main concern. High pressure return tomorrow giving us a pleasant day with seasonable temperatures. The next system to monitor arrives Sunday night into Monday which could overspread widespread rainfall across the region. && .NEAR TERM /UNTIL 6 AM SATURDAY MORNING/... ...Tornado Watch 187 in effect until 10PM This Evening.. As of 4:30PM...Impressive line of convection is already underway downstream of Lake Ontario thanks to a lake shore boundary that served as the lifting mechanism for convection. The line of convection is now entering into the western Mohawk Valley and the southern Adirondacks. The environment includes temperatures in the upper 70s to near 80 in the Mohawk Valley with dew points in the upper 50s. The rather low dew points explains why the SPC mesoanalysis only shows about 1000J/kg of SB CAPE. However, with the advancing shortwave in the Upper Great Lakes spreading its enhanced low level jet into central/eastern NY, the effective shear has increased to 45 to 55kts. In addition, the surface warm front as stalled over the Upper Hudson Valley which serves to increase the low level directional shear. The combination of speed and directional shear and sufficient instability has led to impressive wind signatures on the current convective line. In addition, low-level lapses near 8C/km are rather impressive due to the lower dew points which enhances the potential for strong winds to reach the surface. We have coordinated with the SPC to issue a tornado watch given the environment signatures for potential spin ups/rotation along the approaching QLCS. Previous discussion... GOES16 water vapor shows our compact yet positively shortwave trough progressing across the Upper Great Lakes nearing Lake Huron. Given how far back this shortwave is, it's no surprise the attendant cold front is still far away progressing across southern Canada into the Ohio Valley. If the CAMS are right and we stay mainly dry ahead of the cold front, southwesterly flow this afternoon should allow temperatures to warm nicely into the mid to upper 70s with even the first 80 degree temperatures readings for the Hudson Valley. Dew points are also on track to reach into the upper 50s to low 60s which would contribute to surface based instability. Latest HREF guidance shows MLCAPE values reaching 1000 - 1500J/kg (meager mid-level lapse rates under 7C/km looks to preclude high instability values) along with impressive effective shear values nearing 40-50kts which supports severe storms capable of damaging wind gusts. Lack of "thicker" instability may preclude larger hail (2"+ in diameter) but sufficient instability exists in the -10C to -30C layer with NCAPE values around 0.15 means that frequent lightning will also be a concern. The best 500hPa height falls arrive after 21 UTC across our western Mohawk Valley and southern Adirondack regions which is also when CAMS track the squall line into these areas. Latest HREF shows a "bulls-eye" of 2-5km updraft helicity values >150 m2/s focused in this region. This increases confidence that we may be dealing with a QLCS and any bowing segments that have rear inflow notches with 0-3km shear vectors oriented more perpendicular to the UDCZ could support a quick spin-up. The Mohawk Valley is notorious for enhance severe weather given the orientation of the terrain. Since the squall line should reach this region in addition to the southern Adirondacks, Upper Hudson Valley and western portions of the Capital Region during or shortly after peak heating hours (5pm to 8pm), we will keep a close eye on the squall line/QLCS for any potential embedded rotation. With the 500mb jet also expected to increase up to 50-70kts over our region late this afternoon into this evening, we agree with SPC's placement of the 5% tornado risk. Total rainfall should range 0.25 to 0.75" with locally higher up to 1 to 1.25" in areas hit with multiple storms. However, flooding is not anticipated given that the upper level winds are strong enough that the line of convection should be progressive. Even still, urbanized flooding or flooding in poor drainage areas is possible. The main convection should advance into the Capital region and areas south and west between 00 UTC and 03 UTC but it looks to weaken after 00 UTC as we lose daylight/instability. Showers in the wake of the main line of convection should dissipate by 06 UTC. && .SHORT TERM /6 AM SATURDAY MORNING THROUGH SUNDAY NIGHT/... Compact shortwave should be to our east in New England by 12 UTC Saturday with upper level ridging and surface high pressure building into the Northeast in its wake. Northwest flow should advect in a drier air mass with dew points falling into the 40s through the day. It will be a pleasant day as skies should be mostly sunny with temperatures relatively cooler compared to Friday but still seasonable for mid-May. Highs should reach into the upper 60s to low to mid 70s. Canadian high pressure centered well to our north over the Hudson Bay will continue to dominate our weather pattern Saturday night with mostly clear skies and low winds. Radiational cooling should allow temperatures to fall into the 40s for most areas with near 50 degree readings in the valley. However, with a surface low in the Midwest intensifying as it heads northeastward, its 850hPa warm front should be pushing into the Southern Tier and parts of the Catskills, resulting in weak warm air advection starting after 06 UTC over our area. Thus, cloud coverage may increase over our area late in the night. Impressive compact, closed shortwave in the Plains will continues is eastward track on Sunday. Its associated surface low will also be tracking into MI with its warm front gradually lifting northward. With zonal flow in place aloft, the best CVA and warm air advection looks to hold off until late Sunday afternoon and especially Sunday night. Thus, Sunday should feature increasing clouds with slightly cooler temperatures than Saturday since we will be in the "cool air wedge" ahead of the approaching surface warm front. && .LONG TERM /MONDAY THROUGH FRIDAY/... There is the potential for an extended period of unsettled weather through the long term period, although there still is some uncertainty regarding the exact track and setup. Through the upcoming week, a large upper level low will be dropping across the Ohio Valley towards the mid Atlantic States. This will be a closed off upper level low that will eventually stall out along the eastern seaboard before finally lifting northeast towards New England by next weekend. 500 hpa heights look to be 2 to 3 STD below normal by midweek according to the 12z GEFS. At the same time, surface low pressure will be located off the eastern seaboard, which will likely have some tropical or sub-tropical characteristics. This feature will be lifting northward offshore and some of the moisture will get pulled into the upper level low stalled out near the region. As a result, there will be a prolonged period of repeated showers through the week, although the track of the upper level low will determine which areas see the most rainfall. For now, have gone with likely or categorical POPs to start the week for Monday, and lower POPs towards mid-week, as the upper level low shifts southward. However, if the upper level low were to remain closer, it could remain fairly showery and more cloudy across our area even into the midweek period. Eventually, POPs increase for the late week once again as the upper level low passes back over the area before exiting. There is the potential for some heavy rainfall, especially on Monday, when PWAT values get above 2 std above normal (according to the 12z GEFS). If repeated showers occur through the week, there could be some flooding concerns. Temperatures look cool to start the week due to the clouds/showers with mainly 50s for highs on Monday. Daytime temps should return to the 60s/70s for the mid to late week, and temps could be fairly warm if the upper level low is far enough away during the midweek period. Overnight lows should be mainly in the 40s and no frost/freeze concerns look to occur this week. && .AVIATION /20Z FRIDAY THROUGH WEDNESDAY/... With a warm front lifting north of the TAF sites, our region is located within the warm sector ahead of an approaching storm system. Flying conditions have returned to VFR for all sites with sct- bkn cigs around 3500-5000 ft and it should be mainly dry for the next. few hours. A few rogue showers/t-storms may start to develop by later this afternoon, but the bigger threat will be the approach of a line of showers/thunderstorms for the evening hours ahead of the storm's cold front. Some of these thunderstorms will contain very strong wind gusts and heavy downpours. Will include a TEMPO for IFR conditions with this line of convection and also include the possibility of winds gusting to 40 kts for all sites. Behind the line, flying conditions will return to VFR with winds switching to the west to northwest at 5 to 10 kts. Ceilings will be clearing out. Flying conditions should continue to be VFR into Saturday with just sct-bkn diurnal cumulus. North to northwest winds will be 5 to 10 kts through the day on Saturday. Outlook... Saturday Night: No Operational Impact. NO SIG WX. Sunday: Low Operational Impact. Slight Chance of SHRA. Sunday Night: High Operational Impact. Definite SHRA. Monday: High Operational Impact. Definite SHRA. Monday Night: High Operational Impact. Likely SHRA. Tuesday: Moderate Operational Impact. Chance of SHRA. Tuesday Night: Low Operational Impact. Slight Chance of SHRA. Wednesday: No Operational Impact. NO SIG WX. && .FIRE WEATHER... A warm front will move across eastern New York and western New England this morning into the afternoon, as a milder and more humid air mass will be over the region. Showers and strong to potentially severe thunderstorms will impact the region in the mid afternoon into the early evening ahead of a cold front and an upper level disturbance. High pressure will build in on Saturday with seasonable temperatures. The RH values will only lower to 50 to 75 percent this afternoon with showers and thunderstorms moving in. The RH values will recover to close to 100 percent Saturday morning, and lower to 40 to 55 percent in the afternoon. The winds will be south to southwest at 10 to 20 mph today, and then veer to the west to northwest at 10 to 15 mph tonight. The winds will be north to northwest at 10 to 20 mph on Saturday. A soaking rainfall is likely today into tonight. Stronger wind gusts are possible in thunderstorms. && .HYDROLOGY... Widespread river or flash flooding issues with tonight's showers and thunderstorms is unlikely. A cold front progressing across the Northeast this evening will result in a line of rain and thunderstorms, leaving behind in 0.25 to 0.75 inches of rain with locally higher amounts around 1 inch. Runoff into rivers and streams will allow river levels to rise tonight into this weekend but should not reach flood stage. Any strong to severe thunderstorm tonight will likely result in heavy downpours and could lead to isolated flash flood or poor drainage flooding in low-lying, poor drainage or urban areas. However, given the dry antecedent conditions and high 1, 3 and 3 hourly flash flood guidance from the Northeast River Forecast Center, widespread flooding is not anticipated. The next chance for widespread rainfall arrives late Sunday night into the day on Monday. Since rivers will already be running above normal, we will be monitoring river levels closely. 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...None. NY...None. MA...None. VT...None. && SYNOPSIS...Speciale/Wasula NEAR TERM...Speciale SHORT TERM...Speciale LONG TERM...Frugis AVIATION...Frugis FIRE WEATHER...Speciale HYDROLOGY...Speciale
Hazardous Weather Outlook National Weather Service Albany NY 604 PM EDT Fri May 15 2020 CTZ001-013-MAZ001-025-NYZ032-033-038>043-047>054-058>061-063>066- 082>084-VTZ013>015-161200- Northern Litchfield-Southern Litchfield-Northern Berkshire- Southern Berkshire-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-Western Greene-Eastern Greene- Western Columbia-Eastern Columbia-Western Ulster-Eastern Ulster- Western Dutchess-Eastern Dutchess-Northern Fulton-Southeast Warren- Southern Washington-Bennington-Western Windham-Eastern Windham- 604 PM EDT Fri May 15 2020 ...TORNADO WATCH 187 IN EFFECT UNTIL 10 PM EDT THIS EVENING... This Hazardous Weather Outlook is for northwestern Connecticut, western Massachusetts, east central New York, eastern New York and southern Vermont. .DAY ONE...Tonight. Please listen to NOAA Weather Radio or go to weather.gov on the Internet for more information about the following hazards. Tornado Watch. .DAYS TWO THROUGH SEVEN...Saturday through Thursday. The probability for widespread hazardous weather is low. .SPOTTER INFORMATION STATEMENT... Weather spotters are encouraged to report significant weather conditions according to Standard Operating Procedures while following all local, state and CDC guidelines.
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE ALBANY NY
605 PM EDT FRI MAY 15 2020
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0600 PM TSTM WND DMG 2 SE GREENFIELD CENTER 43.10N 73.82W
05/15/2020 SARATOGA NY 911 CALL CENTER
TREES AND WIRES DOWN ON DANIELS ROAD
&&
EVENT NUMBER ALY2002292
RATHBUNPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE ALBANY NY
608 PM EDT FRI MAY 15 2020
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0602 PM TSTM WND DMG 3 NNE CHARLTON 42.98N 73.94W
05/15/2020 SARATOGA NY TRAINED SPOTTER
1 FOOT DIAMETER TREE DOWN BLOCKING THE WESTBOUND LANES
OF ROUTE 67 AT SWEETMAN ROAD
&&
EVENT NUMBER ALY2002293
DBTPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE ALBANY NY
609 PM EDT FRI MAY 15 2020
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0606 PM TSTM WND DMG 1 S WILTON 43.15N 73.74W
05/15/2020 SARATOGA NY 911 CALL CENTER
TREES DOWN ON NORTHERN PINES ROAD
&&
EVENT NUMBER ALY2002294
RATHBUNSpecial Weather Statement
National Weather Service Albany NY
609 PM EDT Fri May 15 2020
NYZ064>066-152245-
Eastern Dutchess-Western Dutchess-Eastern Ulster-
609 PM EDT Fri May 15 2020
...A STRONG THUNDERSTORM WILL AFFECT SOUTHEASTERN ULSTER AND SOUTHERN
DUTCHESS COUNTIES...
At 609 PM EDT, a strong thunderstorm was located over Marlboro, or
near Poughkeepsie, moving east at 40 mph.
Winds in excess of 40 mph and half inch hail are possible with this
storm.
Locations impacted include...
Poughkeepsie, Beacon, Pawling, Pleasant Valley, Wappingers Falls,
Amenia, Highland, Fishkill, Millbrook, Fairview, Hopewell Junction,
Marlboro, Red Oaks Mill, Myers Corner, Wingdale, Dover Plains, East
Fishkill, Beekman, Tuckers Corner and Baker Corner.
LAT...LON 4147 7400 4152 7400 4154 7399 4158 7395
4159 7395 4158 7405 4167 7409 4189 7350
4155 7353 4152 7366 4149 7394 4144 7398
4144 7399
TIME...MOT...LOC 2209Z 249DEG 37KT 4161 7395
NASPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE ALBANY NY
619 PM EDT FRI MAY 15 2020
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0615 PM TSTM WND DMG FORT EDWARD 43.27N 73.58W
05/15/2020 WASHINGTON NY 911 CALL CENTER
3 LARGE TREES DOWN
&&
EVENT NUMBER ALY2002295
RATHBUNPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE ALBANY NY
623 PM EDT FRI MAY 15 2020
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0613 PM TSTM WND DMG 3 NE GREENWICH 43.12N 73.45W
05/15/2020 WASHINGTON NY 911 CALL CENTER
TREES AND WIRES DOWN ON RYAN ROAD
&&
EVENT NUMBER ALY2002296
RATHBUNThe Albany radar (KENX), 92 km away, was scanning. The volume nearest the first event began at 22:28 UTC.
11 thunderstorm wind. Local standard time, as filed.
Four birch trees of 12-18 inches in diameter were downed on West Sandgate Road.
Trees were downed on Route 313 near the New York/Vermont border.
Power lines were downed in Arlington.
Several large branches up to 25 feet long were downed along Carlen Street.
A 51 mile per hour gust was recorded at the William H. Morse State Airport outside of Bennington.
Trees and wires were downed on Carpenter Hill Road.
Two moderate size trees were down across Route 35.
A tree was downed onto a road in Putney with scattered limbs also down.
Trees and wires were downed on Guilford Street.
Multiple trees and wires were downed in Dummerston.
Route 142 was closed south of Newton Road due to downed trees and wires.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Vermont in 2020Every state in 2020This day in weather historyWarnings in Vermont, May 2020
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: 893925, 893924, 893926, 893927, 893934, 893928, 893929, 893930, 893931, 893932, 893933.