Albany, NY

Weather Forecast Office

May 31, 2017 Severe Weather

Overview

Severe thunderstorms impacted eastern New York and Northwest Connecticut on May 31, 2017 as a cold upper-level disturbance interacted with a moderately unstable airmass. Showers and thunderstorms began in the late morning across western and central New York, and rapidly intensified upon reaching the Capital District around 4 pm. With cold air and strong winds at mid-levels of the atmosphere and moist air near the surface, the environment was prime for large hail, with up to golf ball-size hail reported near Niskayuna. Strong winds also occurred with these storms, particularly in the Colonie area where a microburst (concentrated swath of severe wind damage) was confirmed. These storms weakened east of the Capital District. A second area of storms rapidly strengthened upon entering the Mid-Hudson Valley around 6:30 pm. Again, hail up to golf ball-size was reported in Poughkeepsie, as well as several reports of wind damage. This line of storms eventually merged with an isolated cell and resulted in a brief EF1 tornado in the town of Wappinger in Dutchess County. It was the first tornado of the year in New York State.

Tornado
Microburst
Radar and Satellite
Storm Reports, Photos and Videos
Environment

Tornadoes:

Tornado - Town of Wappinger
Dutchess County, NY

Date	May 31, 2017
Time (Local)	6:58-7:00 pm
EF Rating	1
Est. Peak Winds	100
Path Length	1.25 mi
Max Width	0.25 mi
Injuries/Deaths	None
Summary: The National Weather Service in coordination with Dutchess County Emergency Management officials, have confirmed a brief touchdown of a tornado on May 31. The tornado path began near the intersection of Maloney Road and Route 376. The tornado traveled due east along and just north of Maloney Road for approximately 1.25 miles before dissipating. Damage included numerous snapped hardwood and softwood trees and the roof lifted off a shed.

Track Map

Track Map

The Enhanced Fujita (EF) Scale classifies tornadoes into the following categories:

EF0 Weak 65-85 mph	EF1 Moderate 86-110 mph	EF2 Significant 111-135 mph	EF3 Severe 136-165 mph	EF4 Extreme 166-200 mph	EF5 Catastrophic 200+ mph

Microburst

Microburst - Town of Colonie
Albany County, NY

Date	May 31, 2017
Time (Local)	4:13 pm
Est. Peak Winds	90 mph
Path Length	1 mi
Max Width	100 yards
Injuries/Deaths	None
Summary: The National Weather Service in Albany NY has confirmed a Microburst /Straight Line Wind Damage/ near Colonie in Albany County New York on May 31, 2017. Damage was in a narrow path that began near the intersection of Kings Road and Cordell Road, east southeast to Morris Road. Along this path, numerous trees were uprooted and snapped, roofs were damaged, a flag pole was bent, at least one power pole was snapped and a large overhead door was buckled inward.

Path Map

Track Map

Radar and Satellite:

KENX radar loop from 1-9 pm (courtesy Iowa Environmental Mesonet)

KENX radar images


Fig. 1. KENX radar at 4:12 pm. Clockwise from upper left: 0.5 degree reflectivity (Z), 19.5 degree Z, 0.5 degree differential reflectivity (ZDR), 0.5 degree base velocity (V). The height of the 19.5 degree slice is approximately 24 kft over Schenectady. Crosshairs denotes location of the Colonie microburst.	Fig. 2. As in Fig. 1 but at 4:14 pm.	Fig. 3. KENX radar cross section of reflectivity through the hail-producing storm over the Schenectady area at 4:08 pm.	Fig. 4. KENX radar at 6:58 pm. Clockwise from upper left: 0.5 degree Z, 0.5 degree normalized rotation (nrot), 0.5 degree storm-relative velocity (SRV), 4.4 degree Z. The height of the 4.4 degree slice near Poughkeepsie is around 25 kft. Crosshairs denotes location of the Wappinger tornado.

GOES-16 Visible Imagery Loop (Preliminary, Non-Operational Data) Courtesy Colorado State University

Storm Reports, Photos and Videos

Local Storm Report Maps

Image courtesy of Iowa Environmental Mesonet (IEM). Local Storm Reports (LSR) are also shown plotted on the map according to the legend below.

Photos and Videos


UAlbany Dept. of Atmospheric and Environmental Sciences Mohawk Tower time-lapse webcam from 1:13 to 8:50 pm 
looking west from the UAlbany Uptown Campus


Colonie microburst damage from NWS survey	Colonie microburst damage from NWS survey

Local Storm Report Text Listing



PRELIMINARY LOCAL STORM REPORT...SUMMARY
NATIONAL WEATHER SERVICE ALBANY NY
1257 AM EDT THU JUN 01 2017

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0339 PM     HAIL             HAGUE                   43.75N  73.50W
05/31/2017  M1.00 INCH       WARREN             NY   FACEBOOK        

0340 PM     HAIL             3 SW DARROWSVILLE       43.58N  73.86W
05/31/2017  M0.88 INCH       WARREN             NY   PUBLIC          

0350 PM     TSTM WND DMG     GLEN                    42.89N  74.35W
05/31/2017                   MONTGOMERY         NY   FACEBOOK        

            TREE DOWN ON ROAD 

0415 PM     HAIL             ROTTERDAM               42.78N  73.95W
05/31/2017  E1.00 INCH       SCHENECTADY        NY   FACEBOOK        

0418 PM     HAIL             SOUTH SCHENECTADY       42.79N  73.97W
05/31/2017  M1.00 INCH       SCHENECTADY        NY   NWS EMPLOYEE    

0418 PM     TSTM WND DMG     1 NE FORT HUNTER        42.75N  73.94W
05/31/2017                   ALBANY             NY   LAW ENFORCEMENT 

            TREE DOWN ON EAST LYDIUS STREET 

0420 PM     TSTM WND DMG     HAWTHORNE HILL          42.80N  73.89W
05/31/2017                   SCHENECTADY        NY   EMERGENCY MNGR  

            TREE INTO HOUSE ON EAST COUNTRY CLUB DRIVE IN 
            NISKAYUNA. NO INJURIES REPORTED. 

0420 PM     TSTM WND DMG     COLONIE                 42.73N  73.85W
05/31/2017                   ALBANY             NY   METEOROLOGIST   

            TREES AND WIRES DOWN 

0420 PM     TSTM WND DMG     1 SW STANFORD HEIGHTS   42.76N  73.90W
05/31/2017                   ALBANY             NY   LAW ENFORCEMENT 

            TREE AND WIRES DOWN AND A TRANSFORMER ON FIRE ON 
            CORDELL ROAD 

0421 PM     HAIL             1 NNW NISKAYUNA         42.83N  73.90W
05/31/2017  M1.75 INCH       SCHENECTADY        NY   NWS EMPLOYEE    

0421 PM     TSTM WND DMG     2 SW LISHA KILL         42.74N  73.89W
05/31/2017                   ALBANY             NY   LAW ENFORCEMENT 

            MULTIPLE TREES DOWN ON CURRY ROAD EXT 

0421 PM     TSTM WND DMG     1 WSW MAYWOOD           42.74N  73.89W
05/31/2017                   ALBANY             NY   LAW ENFORCEMENT 

            TREES AND WIRES DOWN ALONG KINGS ROAD 

0422 PM     TSTM WND DMG     1 SSW STANFORD HEIGHTS  42.75N  73.90W
05/31/2017                   ALBANY             NY   LAW ENFORCEMENT 

            TREES AND WIRES DOWN AT THE INTERSECTION OF KINGS ROAD 
            AND MORRIS ROAD 

0422 PM     TSTM WND DMG     1 W KARNER              42.72N  73.88W
05/31/2017                   ALBANY             NY   LAW ENFORCEMENT 

            TREE DOWN AT THE INTERSECTION OF EAST OLD STATE ROAD 
            AND KINGS ROAD 

0422 PM     TSTM WND DMG     1 S MAYWOOD             42.73N  73.86W
05/31/2017                   ALBANY             NY   LAW ENFORCEMENT 

            TREE DOWN ON ALBANY STREET 

0422 PM     TSTM WND DMG     1 WSW LISHA KILL        42.75N  73.88W
05/31/2017                   ALBANY             NY   LAW ENFORCEMENT 

            TREES AND WIRES DOWN ON MORRIS ROAD 

0424 PM     TSTM WND DMG     1 S NEW SALEM           42.61N  73.97W
05/31/2017                   ALBANY             NY   LAW ENFORCEMENT 

            TREE DOWN AT THE INTERSECTION OF NEW SCOTLAND ROAD AT 
            STOVE PIPE ROAD 

0425 PM     HAIL             NISKAYUNA               42.82N  73.90W
05/31/2017  E0.88 INCH       SCHENECTADY        NY   TRAINED SPOTTER 

0426 PM     TSTM WND DMG     2 W MALTA               42.97N  73.83W
05/31/2017                   SARATOGA           NY   FIRE DEPT/RESCUE

            TREES AND WIRES DOWN 

0430 PM     TSTM WND DMG     1 N STANFORD HEIGHTS    42.78N  73.89W
05/31/2017                   SCHENECTADY        NY   FACEBOOK        

            TREES AND WIRES DOWN ON ROAD 

0430 PM     TSTM WND DMG     MOHAWK VIEW             42.78N  73.79W
05/31/2017                   ALBANY             NY   FACEBOOK        

            TREE DOWN ON ROAD. 

0434 PM     TSTM WND DMG     1 ESE LOUDONVILLE       42.70N  73.75W
05/31/2017                   ALBANY             NY   LAW ENFORCEMENT 

            TREE DOWN ON PRINCESS LANE 

0435 PM     TSTM WND DMG     LOUDONVILLE             42.71N  73.77W
05/31/2017                   ALBANY             NY   LAW ENFORCEMENT 

            TREE DOWN ON OSBORNE ROAD 

0436 PM     HAIL             SCHENECTADY             42.80N  73.93W
05/31/2017  E1.00 INCH       SCHENECTADY        NY   FACEBOOK        

0436 PM     TSTM WND DMG     1 ESE LOUDONVILLE       42.70N  73.76W
05/31/2017                   ALBANY             NY   LAW ENFORCEMENT 

            TREE DOWN ON CHERRY TREE ROAD 

0440 PM     HAIL             1 SSE PLACE CORNERS     42.36N  73.99W
05/31/2017  E1.00 INCH       GREENE             NY   TRAINED SPOTTER 

0440 PM     TSTM WND DMG     WATERVLIET              42.72N  73.70W
05/31/2017                   ALBANY             NY   LAW ENFORCEMENT 

            TREE DOWN AT THE INTERSECTION OF 14TH STREET AND 2ND 
            AVE 

0446 PM     HAIL             1 N SYCAWAY             42.76N  73.65W
05/31/2017  M0.88 INCH       RENSSELAER         NY   NWS EMPLOYEE    

0450 PM     TSTM WND DMG     1 SSE IVES CORNER       42.68N  73.52W
05/31/2017                   RENSSELAER         NY   AMATEUR RADIO   

            TREES AND WIRES DOWN 

0650 PM     HAIL             1 SSE POUGHKEEPSIE      41.68N  73.91W
05/31/2017  M1.75 INCH       DUTCHESS           NY   TRAINED SPOTTER 

            GOLFBALL SIZE HAIL REPORTED ON MITCHELL AVE 

0650 PM     HAIL             POUGHKEEPSIE            41.69N  73.92W
05/31/2017  M0.75 INCH       DUTCHESS           NY   PUBLIC          

0656 PM     HAIL             ARLINGTON               41.70N  73.89W
05/31/2017  M1.00 INCH       DUTCHESS           NY   FIRE DEPT/RESCUE

0715 PM     TSTM WND DMG     HOPEWELL JUNCTION       41.59N  73.80W
05/31/2017                   DUTCHESS           NY   PUBLIC          

            TREES DOWN 

0727 PM     TSTM WND DMG     EAST FISHKILL           41.55N  73.80W
05/31/2017                   DUTCHESS           NY   911 CALL CENTER 

            TREES DOWN 

0730 PM     TSTM WND DMG     HURD CORNERS            41.59N  73.58W
05/31/2017                   DUTCHESS           NY   PUBLIC          

            MULTIPLE MAPLE TREES DOWNED 

0730 PM     TSTM WND DMG     WAPPINGERS FALLS        41.60N  73.92W
05/31/2017                   DUTCHESS           NY   EMERGENCY MNGR  

            TIME ESTIMATED. TREE TOPS SNAPPED OFF. HOUSE IMPALED BY 
            BRANCHES. SHED BLOWN DOWN AND PARTIAL COLLAPSE OF HOUSE. 
            EVENT OCCURED ON MALONEY RD. NEAR RT. 376 

0748 PM     HAIL             NEW MILFORD             41.59N  73.41W
05/31/2017  M1.00 INCH       LITCHFIELD         CT   PUBLIC          

0750 PM     HAIL             2 WNW ROXBURY STATION   41.57N  73.37W
05/31/2017  M1.00 INCH       LITCHFIELD         CT   PUBLIC

Environment

A severe weather event occurred with a strong short-wave trough moving across the region during the mid to late afternoon. This short-wave was associated with a closed/cut-off low centered south of Hudson Bay over north-central Ontario (Fig. 1). The pre-convective environment was moderately unstable with surface-based CAPE of 1000-1500 J/kg (Fig. 2) and mixed-layer CAPE around 1000 J/kg with dewpoints in the 50s to lower 60s. The mid-level lapse rates were extremely steep in the 7-7.5°C/km range based on the 18Z KALY sounding (Figs. 3, 4). The 0-6 km bulk shear was high in the 50+kt range (58 kts on the 18Z sounding; Figs 3, 5) with the strongest shear in the 700-500 hPa layer due to the strong mid-level jet max moving across region in the southwest flow aloft. The wet bulb zero heights were low in the 6-8 kft AGL range with the -20°C heights as low as 18 kft AGL per the 18Z KALY sounding. Large hail and damaging winds were the main threats with the cold pool aloft. Tornadoes were a secondary threat with low values of shear in the 0-1 km layer, though still a non-zero threat with backed surface winds up the Hudson Valley. The convective mode was multi-cells and supercells merging into lines and clusters with the unidirectional southwesterly flow in the mid to upper levels.

Showers and thunderstorms developed along the leading edge of the midlevel height falls across western and central New York in the late morning to early afternoon. The storms were sub-severe as earlier clearing had led to mixing drier air to the surface, with dewpoints in the upper 40s and low 50s. Meanwhile, within the Hudson Valley, early clouds did not burn off until late morning. A light south-southeast flow up the valley maintained surface dewpoints in the upper 50s to low 60s as temperatures warmed into the lower 70s. Surface convergence was maximized where the westerly outflow from the sub-severe storms in Montgomery County intersected with the southeasterly flow up the Hudson Valley, turning the corner into the eastern Mohawk Valley (Figs 6, 7). This convergence, along with the storms entering a more unstable (higher surface theta-e) environment, led to a rapid strengthening of the storms as they moved into the Capital District. A similar situation may have occurred later when the trailing, southwest end of the storms entered the mid-Hudson Valley and quickly strengthened (Figs 8, 9).


Figure 1: 500 mb map at 12Z 31 May.	Figure 2: Surface-based CAPE (contours, J/kg) and CIN (shading, J/kg) valid 18Z 31 May from SPC Mesoanalysis.	Figure 3: 18Z KALY sounding.


Figure 4: 700-500 mb lapse rates (K/km) valid 18Z 31 May from SPC Mesoanalysis.	Figure 5: 0-6 km bulk shear (kt) valid 18Z 31 May from SPC Mesoanalysis.	Figure 6: Gridded analysis of temperature (F, fill), dewpoint (F, contour), and wind (mph, arrows) from New York State Mesonet valid 1930Z. Image created by Nick Bassill using New York State Mesonet Data.


Figure 7: Gridded analysis of temperature (F, fill), and composite radar from New York State Mesonet valid 1930Z. Image created by Nick Bassill using New York State Mesonet Data.	Figure 8: As in Fig. 6 but at 2200Z. Image created by Nick Bassill using New York State Mesonet Data.	Figure 9: As in Fig. 7 but at 2200Z. Image created by Nick Bassill using New York State Mesonet Data.