Alert archive / New Jersey / Mesoscale Discussions in 2017
Mesoscale Discussion 1413
The Storm Prediction Center issued this mesoscale discussion at Jul 24, 2017, 12:41 AM EDT for 4 states. It was in force for 2 hr.
The area
The outline as issued.
The facts
- Issued
- Jul 24, 2017, 12:41 AM EDT (04:41 UTC)
- Expired
- Jul 24, 2017, 2:45 AM EDT
- In force
- 2 hr
- Issued by
- the Storm Prediction Center
- Chance of a watch
- 20%
All 24 counties
Kent County, DE, New Castle County, DE, Anne Arundel County, MD, Baltimore County, MD, Cecil County, MD, City of Baltimore, MD, Harford County, MD, Kent County, MD, Queen Anne's County, MD, Atlantic County, NJ, Burlington County, NJ, Camden County, NJ, Cumberland County, NJ, Gloucester County, NJ, Mercer County, NJ, Middlesex County, NJ, Monmouth County, NJ, Ocean County, NJ, Salem County, NJ, Bucks County, PA, Chester County, PA, Delaware County, PA, Montgomery County, PA, Philadelphia County, PA
The radar
The Philadelphia radar (KDIX), 27 km from the middle of the area, began a volume at 04:41 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
Brookhaven, NY (KOKX), launched 00:00Z, 4.7 hours before the alert went out and 168 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
- 725 m above ground
- 0-6 km bulk shear
- 32 kt
- 0-1 km storm-relative helicity
- -1 m²/s²
- 0-3 km storm-relative helicity
- 58 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
321
ACUS11 KWNS 240441
SWOMCD
SPC MCD 240441
NJZ000-PAZ000-DEZ000-MDZ000-240645-
Mesoscale Discussion 1413
NWS Storm Prediction Center Norman OK
1141 PM CDT Sun Jul 23 2017
Areas affected...Eastern Maryland into New Jersey
Concerning...Severe potential...Watch unlikely
Valid 240441Z - 240645Z
Probability of Watch Issuance...20 percent
SUMMARY...Areas of storms may increase across the region, but are
expected to mainly be non-severe over land. A few strong wind gusts
appear most likely.
DISCUSSION...Modest warm advection in the low-levels is helping to
create lift, resulting in a rash of thunderstorm development from
eastern MD into southern NJ. Recently, an impressive supercell had
developed near the NJ coast and is now offshore. To the west, cells
have shown mainly weak/broad rotation at times. This corresponds
well with observed wind profiles, which show veering winds with
height, but with weak magnitude resulting in small hodographs.
Models show this general area of storms lifting east/northeastward
tonight, with perhaps some increase in storm intensity over the
ocean. A few strong wind gusts cannot be ruled out with any cells
over land, especially if they show signs of rotation, or, if they
conglomerate into larger clusters. The weak lapse rate environment,
unfavorable time of day, and modest low-level shear should keep
tornado threat minimal. However, trends will continue to be
monitored.
..Jewell/Weiss.. 07/24/2017
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...PHI...CTP...LWX...
LAT...LON 39297369 39157487 38897653 39057674 39537688 39937642
40287562 40567364 40727240 40637214 40197188 39617214
39457233 39297369SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 24, 2:17 PM EDT | Mesoscale Discussion | SPC | New Castle | 118 min |
| Jul 24, 6:09 PM EDT | Mesoscale Discussion | SPC | Kent, New Castle, Sussex | 3 hr |
Nearby
Mesoscale Discussions in New Jersey, 2017Mesoscale Discussions in Maryland, 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.