Alert archive / New York / Mesoscale Discussions in 2017

Mesoscale Discussion 210

February 25, 20174 states

The Storm Prediction Center issued this mesoscale discussion at Feb 25, 2017, 12:16 PM EST for 4 states. It was in force for 89 min.

The area

The outline as issued.

The facts

Issued
Feb 25, 2017, 12:16 PM EST (17:16 UTC)
Expired
Feb 25, 2017, 1:45 PM EST
In force
89 min
Issued by
the Storm Prediction Center
Chance of a watch
40%
All 64 counties

New Castle County, DE, Burlington County, NJ, Camden County, NJ, Essex County, NJ, Gloucester County, NJ, Hunterdon County, NJ, Mercer County, NJ, Middlesex County, NJ, Morris County, NJ, Passaic County, NJ, Somerset County, NJ, Sussex County, NJ, Union County, NJ, Warren County, NJ, Albany County, NY, Broome County, NY, Chenango County, NY, Cortland County, NY, Delaware County, NY, Fulton County, NY, Greene County, NY, Hamilton County, NY, Herkimer County, NY, Lewis County, NY, Madison County, NY, Montgomery County, NY, Oneida County, NY, Onondaga County, NY, Orange County, NY, Oswego County, NY, Otsego County, NY, Saratoga County, NY, Schenectady County, NY, Schoharie County, NY, Sullivan County, NY, Tioga County, NY, Tompkins County, NY, Ulster County, NY, Warren County, NY, Berks County, PA, Bradford County, PA, Bucks County, PA, Carbon County, PA, Chester County, PA, Columbia County, PA, Dauphin County, PA, Delaware County, PA, Lackawanna County, PA, Lancaster County, PA, Lebanon County, PA, Lehigh County, PA, Luzerne County, PA, Monroe County, PA, Montgomery County, PA, Montour County, PA, Northampton County, PA, Northumberland County, PA, Philadelphia County, PA, Pike County, PA, Schuylkill County, PA, Sullivan County, PA, Susquehanna County, PA, Wayne County, PA, Wyoming County, PA

The radar

The Binghamton radar (KBGM), 62 km from the middle of the area, began a volume at 17:17 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 watches that followed

Watches SPC issued over any of the same counties within four hours of this discussion.

The nearest sounding before it

Albany, NY (KALY), launched 12:00Z, 5.3 hours before the alert went out and 138 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 2017-02-25Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 3 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 2017-02-25The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 263 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
3 J/kg
Mixed-layer CIN
-449 J/kg
Mixed-layer LCL
881 m above ground
0-6 km bulk shear
37 kt
0-1 km storm-relative helicity
263 m²/s²
0-3 km storm-relative helicity
358 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

353 
ACUS11 KWNS 251716
SWOMCD
SPC MCD 251716 
NYZ000-NJZ000-PAZ000-DEZ000-MDZ000-251845-

Mesoscale Discussion 0210
NWS Storm Prediction Center Norman OK
1116 AM CST Sat Feb 25 2017

Areas affected...central and eastern NY...eastern PA...much of NJ
and northern DE

Concerning...Severe potential...Watch possible 

Valid 251716Z - 251845Z

Probability of Watch Issuance...40 percent

SUMMARY...A line of storms is expected to track quickly eastward
across central and eastern NY, eastern PA and into northern DE and
NJ this afternoon and early evening. Some isolated strong cells
could produce strong/damaging wind gusts. Trends will be monitored
for possible watch issuance within the next couple of hours.

DISCUSSION...A line of convection along/just ahead of the eastward
advancing cold front has been increasing in intensity over the last
30 minutes or so. Downstream, the airmass has warmed into the 60s to
lower 70s in broken cloudiness with dewpoints in the mid to upper
50s. This has allowed weak destabilization to occur, with
mesoanalysis indicating around 500 J/kg SBCAPE across the region.
Some additional destabilization is possible through the afternoon,
which should further aid in storm organization and intensification
over the next several hours. Strong deep layer shear parallel to the
front will favor line segments with perhaps some bowing in stronger
segments. While thermodynamics are unimpressive, fast storm motion
in conjunction with strong shear profiles may result in some
strong/damaging gusts. Modest lapse rates and lack of stronger
instability should limit large hail potential, though some small
hail is possible in strongest cells. Trends will be monitored and a
watch may be needed within the next couple of hours if
intensification continues. .

..Leitman/Hart.. 02/25/2017

...Please see www.spc.noaa.gov for graphic product...

ATTN...WFO...BTV...OKX...ALY...PHI...BGM...BUF...CTP...

LAT...LON   43447639 43957559 44187474 44167399 44007352 42927364
            41787387 40377440 39857466 39587542 39557582 40017678
            40967700 42337671 43447639

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Feb 25, 12:24 PM ESTMesoscale DiscussionSPCKent, Sussex2 hr
Feb 25, 1:30 PM ESTSevere Thunderstorm WatchSPCKent, New Castle, Sussex6 hr
Feb 25, 4:26 PM ESTMesoscale DiscussionSPCKent, New Castle, Sussex94 min
Feb 25, 2:46 PM ESTSevere Thunderstorm WatchSPCBergen, Essex, Hunterdon, Mercer, Middlesex, Monmouth and 7 more5 hr
Feb 25, 4:44 PM ESTMesoscale DiscussionSPCBergen, Essex, Hudson, Hunterdon, Mercer, Middlesex and 7 more91 min
Feb 24, 8:49 PM ESTMesoscale DiscussionSPCBeaver, Crawford, Lawrence, Mercer, Washington116 min

Nearby

Mesoscale Discussions in New York, 2017Mesoscale Discussions in Pennsylvania, 2017Mesoscale Discussions in New Jersey, 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.