Alert archive / New York / Mesoscale Discussions in 2017
Mesoscale Discussion 921
The Storm Prediction Center issued this mesoscale discussion at May 30, 2017, 4:03 PM EDT for 25 counties in New York; 19 counties in Pennsylvania. It was in force for 117 min.
The area
The outline as issued.
The facts
- Issued
- May 30, 2017, 4:03 PM EDT (20:03 UTC)
- Expired
- May 30, 2017, 6:00 PM EDT
- In force
- 117 min
- Issued by
- the Storm Prediction Center
All 44 counties
Broome County, NY, Cayuga County, NY, Chemung County, NY, Chenango County, NY, Cortland County, NY, Fulton County, NY, Hamilton County, NY, Herkimer County, NY, Lewis County, NY, Madison County, NY, Montgomery County, NY, Oneida County, NY, Onondaga County, NY, Ontario County, NY, Oswego County, NY, Otsego County, NY, Saratoga County, NY, Schuyler County, NY, Seneca County, NY, Steuben County, NY, Tioga County, NY, Tompkins County, NY, Warren County, NY, Washington County, NY, Yates County, NY, Adams County, PA, Bedford County, PA, Blair County, PA, Bradford County, PA, Centre County, PA, Clinton County, PA, Cumberland County, PA, Franklin County, PA, Fulton County, PA, Huntingdon County, PA, Juniata County, PA, Lycoming County, PA, Mifflin County, PA, Perry County, PA, Potter County, PA, Snyder County, PA, Sullivan County, PA, Tioga County, PA, Union County, PA
The radar
The Binghamton radar (KBGM), 24 km from the middle of the area, began a volume at 20:03 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.
The nearest sounding before it
Albany, NY (KALY), launched 12:00Z, 8.1 hours before the alert went out and 205 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.
- Mixed-layer CAPE
- 0 J/kg
- Mixed-layer CIN
- No buoyant parcel
- Mixed-layer LCL
- 592 m above ground
- 0-6 km bulk shear
- 39 kt
- 0-1 km storm-relative helicity
- 68 m²/s²
- 0-3 km storm-relative helicity
- 116 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
696
ACUS11 KWNS 302003
SWOMCD
SPC MCD 302003
VTZ000-NYZ000-PAZ000-302200-
Mesoscale Discussion 0921
NWS Storm Prediction Center Norman OK
0303 PM CDT Tue May 30 2017
Areas affected...Central PA into central and parts of eastern NY
Concerning...Severe Thunderstorm Watch 299...
Valid 302003Z - 302200Z
The severe weather threat for Severe Thunderstorm Watch 299
continues.
SUMMARY...Severe-weather threat continues across central
Pennsylvania into mainly central New York, while the northeast part
of WW 299 should maintain a limited severe storm potential, given a
more stable environment. Damaging winds and hail remain the primary
severe-weather risk with the strongest storms.
DISCUSSION...Trends in satellite, surface observations and WSR-88D
VWP data indicated a decidedly veered wind field across western PA
into western NY, with a narrow theta-e axis has shifted east into
central PA to central NY. Mosaic radar imagery showed the ongoing
strong to severe storms were located within this moist and unstable
environment with MLCAPE up to around 500 J/kg. Despite marginal
instability, strong bulk shear will continue to favor organized
storms with damaging winds and hail as the primary threats. The
overall severe-weather threat will remain limited with eastward
extent due to extensive low-level clouds into eastern PA to the
northeast part of WW 299 in eastern NY, where instability is quite
low.
..Peters.. 05/30/2017
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...BTV...ALY...BGM...BUF...CTP...
LAT...LON 39777856 40877836 42017787 43007726 43657617 44287570
44047502 43957421 43727336 43097320 42867359 42927430
42537486 42107555 41747617 40847687 39777696 39727789
39757851 39777856SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 30, 12:03 PM EDT | Mesoscale Discussion | SPC | Allegany, Chemung, Schuyler, Seneca, Steuben, Tompkins and 1 more | 2 hr |
| May 30, 12:39 PM EDT | Severe Thunderstorm Watch | SPC | Allegany, Broome, Cattaraugus, Cayuga, Chautauqua, Chemung and 30 more | 6 hr |
Nearby
Mesoscale Discussions in New York, 2017Mesoscale Discussions in Pennsylvania, 2017Every mesoscale discussion 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.