Alert archive / New York / Severe Thunderstorm Watches in 2017

Severe Thunderstorm Watch 417

July 17, 201724 counties in New York; Bradford County, Susquehanna County, Pennsylvania; 12 counties in Vermont

The Storm Prediction Center issued this severe thunderstorm watch at Jul 17, 2017, 12:48 PM EDT for 24 counties in New York; Bradford County, Susquehanna County, Pennsylvania; 12 counties in Vermont. It was in force for 7 hr.

The area

The outline as issued.

The facts

Issued
Jul 17, 2017, 12:48 PM EDT (16:48 UTC)
Expired
Jul 17, 2017, 8:00 PM EDT
In force
7 hr
Issued by
the Storm Prediction Center
Largest hail expected
1.5 in
Strongest gust expected
60 kt
All 38 counties

Albany County, NY, Broome County, NY, Chemung County, NY, Chenango County, NY, Cortland County, NY, Delaware County, NY, Essex County, NY, Fulton County, NY, Greene County, NY, Hamilton County, NY, Herkimer County, NY, Madison County, NY, Montgomery County, NY, Oneida County, NY, Onondaga County, NY, Otsego County, NY, Rensselaer County, NY, Saratoga County, NY, Schenectady County, NY, Schoharie County, NY, Tioga County, NY, Tompkins County, NY, Warren County, NY, Washington County, NY, Bradford County, PA, Susquehanna County, PA, Addison County, VT, Bennington County, VT, Caledonia County, VT, Chittenden County, VT, Essex County, VT, Lamoille County, VT, Orange County, VT, Orleans County, VT, Rutland County, VT, Washington County, VT, Windham County, VT, Windsor County, VT

The radar

The Albany radar (KENX), 75 km from the middle of the area, began a volume at 16:50 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

What SPC expected

The probabilities SPC published with the watch, for the watch area over its life.

Two or more tornadoes
10%
One or more EF2 to EF5 tornadoes
2%
Ten or more severe wind reports
50%
One or more gusts of 65 knots or more
10%
Ten or more severe hail reports
30%
One or more hailstones of 2 inches or more
10%
Six or more combined severe hail and wind reports
70%

Warnings issued inside it

32 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.

IssuedProductOfficeCountiesLasted
Jul 17, 1:07 PM EDTSevere Thunderstorm WarningBGMBroome53 min
Jul 17, 1:18 PM EDTSevere Thunderstorm WarningBGMChenango, Otsego42 min
Jul 17, 1:31 PM EDTSevere Thunderstorm WarningALYHamilton, Warren59 min
Jul 17, 1:53 PM EDTSevere Thunderstorm WarningBGMChemung, Schuyler, Steuben67 min
Jul 17, 1:54 PM EDTSevere Thunderstorm WarningALYFulton, Hamilton, Herkimer66 min
Jul 17, 1:56 PM EDTSevere Thunderstorm WarningBGMBroome64 min
Jul 17, 2:02 PM EDTFlash Flood WarningBTVLamoille, Washington6 hr
Jul 17, 2:16 PM EDTSevere Thunderstorm WarningBTVRutland, Windsor59 min
Jul 17, 2:18 PM EDTSevere Thunderstorm WarningBGMOneida42 min
Jul 17, 2:28 PM EDTSevere Thunderstorm WarningALYFulton, Hamilton62 min
Jul 17, 2:34 PM EDTFlash Flood WarningBGMSusquehanna6 hr
Jul 17, 2:50 PM EDTSevere Thunderstorm WarningBGMBroome, Tioga55 min
Jul 17, 3:10 PM EDTSevere Thunderstorm WarningBGMChemung35 min
Jul 17, 3:27 PM EDTSevere Thunderstorm WarningBGMChemung, Tioga48 min
Jul 17, 3:39 PM EDTFlash Flood WarningBGMBroome, Tioga3 hr
Jul 17, 3:43 PM EDTSevere Thunderstorm WarningBGMBroome, Tioga47 min
Jul 17, 3:44 PM EDTSevere Thunderstorm WarningALYSaratoga, Warren61 min
Jul 17, 3:53 PM EDTSevere Thunderstorm WarningALYHerkimer25 min
Jul 17, 4:26 PM EDTSevere Thunderstorm WarningBGMBroome, Chenango, Delaware49 min
Jul 17, 4:30 PM EDTSevere Thunderstorm WarningALYSaratoga, Schenectady45 min
Jul 17, 4:38 PM EDTSevere Thunderstorm WarningBGMBroome52 min
Jul 17, 4:47 PM EDTSevere Thunderstorm WarningALYSaratoga, Warren, Washington58 min
Jul 17, 4:56 PM EDTSevere Thunderstorm WarningBGMLackawanna, Susquehanna, Wyoming49 min
Jul 17, 5:18 PM EDTSevere Thunderstorm WarningBTVRutland, Windsor57 min
Jul 17, 5:26 PM EDTSevere Thunderstorm WarningBGMBradford, Wyoming34 min
Jul 17, 5:29 PM EDTFlash Flood WarningBTVRutland, Windsor3 hr
Jul 17, 5:35 PM EDTSevere Thunderstorm WarningBGMOneida23 min
Jul 17, 5:43 PM EDTSevere Thunderstorm WarningBGMDelaware50 min
Jul 17, 5:50 PM EDTFlash Flood WarningALYSaratoga, Schenectady5 hr
Jul 17, 6:13 PM EDTSevere Thunderstorm WarningBTVWindsor62 min
Jul 17, 7:17 PM EDTSevere Thunderstorm WarningALYWindham43 min
Jul 17, 7:38 PM EDTFlash Flood WarningALYBennington, Windham3 hr

Discussions around it

SPC mesoscale discussions over the same counties from four hours before the watch to its end.

The nearest sounding before it

Albany, NY (KALY), launched 12:00Z, 4.8 hours before the alert went out and 81 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-pSkew-T log-p diagram, Albany, NY at 12:00Z on 2017-07-17Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 171 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Albany, NY at 12:00Z on 2017-07-17The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 42 square meters per square second.193958Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
171 J/kg
Mixed-layer CIN
-165 J/kg
Mixed-layer LCL
1038 m above ground
0-6 km bulk shear
30 kt
0-1 km storm-relative helicity
42 m²/s²
0-3 km storm-relative helicity
79 m²/s²
Significant tornado parameter
0.0
Supercell composite
-0.0

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jul 17, 12:14 PM EDTMesoscale DiscussionSPCGrafton, Sullivan2 hr
Jul 17, 6:58 PM EDTMesoscale DiscussionSPCBelknap, Carroll, Cheshire, Grafton, Merrimack, Sullivan62 min
Jul 17, 3:37 PM EDTMesoscale DiscussionSPCAlbany, Broome, Cayuga, Chemung, Chenango, Cortland and 21 more53 min

Nearby

Severe Thunderstorm Watches in New York, 2017Severe Thunderstorm Watches in Vermont, 2017Severe Thunderstorm Watches in Pennsylvania, 2017Every severe thunderstorm watch in 2017

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.