Alert archive / New York / Mesoscale Discussions in 2011
Mesoscale Discussion 40
The Storm Prediction Center issued this mesoscale discussion at Jan 21, 2011, 12:30 AM EST for 5 states. It was in force for 5 hr.
The area
The outline as issued.
The facts
- Issued
- Jan 21, 2011, 12:30 AM EST (05:30 UTC)
- Expired
- Jan 21, 2011, 5:30 AM EST
- In force
- 5 hr
- Issued by
- the Storm Prediction Center
All 46 counties
Berkshire County, MA, Bristol County, MA, Essex County, MA, Franklin County, MA, Hampden County, MA, Hampshire County, MA, Middlesex County, MA, Norfolk County, MA, Plymouth County, MA, Suffolk County, MA, Worcester County, MA, Bergen County, NJ, Essex County, NJ, Hudson County, NJ, Hunterdon County, NJ, Morris County, NJ, Passaic County, NJ, Somerset County, NJ, Sussex County, NJ, Union County, NJ, Warren County, NJ, Bronx County, NY, Columbia County, NY, Dutchess County, NY, Greene County, NY, Kings County, NY, Nassau County, NY, New York County, NY, Orange County, NY, Putnam County, NY, Queens County, NY, Richmond County, NY, Rockland County, NY, Sullivan County, NY, Ulster County, NY, Westchester County, NY, Carbon County, PA, Lehigh County, PA, Monroe County, PA, Northampton County, PA, Pike County, PA, Bristol County, RI, Kent County, RI, Newport County, RI, Providence County, RI, Washington County, RI
The radar
The Brookhaven radar (KOKX), 71 km from the middle of the area, began a volume at 05:28 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, 5.5 hours before the alert went out and 71 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
- 1458 m above ground
- 0-6 km bulk shear
- 74 kt
- 0-1 km storm-relative helicity
- 51 m²/s²
- 0-3 km storm-relative helicity
- 215 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
115
ACUS11 KWNS 210531
SWOMCD
SPC MCD 210530
MAZ000-RIZ000-CTZ000-NYZ000-NJZ000-PAZ000-211030-
MESOSCALE DISCUSSION 0040
NWS STORM PREDICTION CENTER NORMAN OK
1130 PM CST THU JAN 20 2011
AREAS AFFECTED...PORTIONS OF THE NORTHEAST AND SRN NEW ENGLAND
CONCERNING...HEAVY SNOW
VALID 210530Z - 211030Z
BANDS OF MODERATE TO HEAVY SNOW WILL DEVELOP OVERNIGHT ALONG THE
I-84/95 CORRIDORS FROM ERN PA INTO MA. SNOWFALL RATES FROM 1 TO 2
IN/HR SHOULD OCCUR...MOST LIKELY ACROSS PORTIONS OF SRN NEW ENGLAND
AROUND OR JUST AFTER 12Z. ALTHOUGH DURATION OF HEAVY SNOW RATES IN
ANY ONE LOCATION SHOULD REMAIN RELATIVELY SHORT...HIGH TRAVEL IMPACT
ON MORNING RUSH HOUR APPEARS PROBABLE FROM THE NEW YORK CITY TO
BOSTON METRO AREAS.
05Z SURFACE ANALYSIS PLACED A 1004 MB CYCLONE OVER S-CNTRL PA WITH A
QUASI-STATIONARY/WARM FRONT DRAPED EWD TO LONG ISLAND. 00Z MODELS
ARE HIGHLY CONSISTENT WITH THE AMPLIFICATION OF AN UPPER-LEVEL SHORT
WAVE TROUGH /CURRENTLY CROSSING THE ERN GREAT LAKES AND UPPER OH
VALLEY/...RESULTING IN DEEPENING OF THE SURFACE LOW OFF THE NJ/LONG
ISLAND COAST THROUGH 12Z. STRENGTHENING LOWER-LEVEL WAA/ISENTROPIC
LIFT IN CONJUNCTION WITH MID-LEVEL DCVA WILL RESULT IN ROBUST FORCED
ASCENT DEVELOPING FROM ERN PA TO MA. THIS SUPPORTS THE AXIS OF
HIGHEST QPF/QSF DEPICTED IN THE LATEST SREF MEAN...GFS...HRRR...AND
ETA-KF CONTROL RUN OF THE SREF. SNOWFALL RATES WITHIN THIS AXIS
SHOULD REACH 1 IN/HR...WITH RATES NEAR 2 IN/HR INTO PORTIONS OF SRN
NEW ENGLAND TOWARDS 11-14Z.
THE 00Z NAM IS NOT QUITE AS ROBUST WITH INLAND QPF THAN IN PREVIOUS
RUNS WITH GREATER OFFSHORE RAINFALL DEVELOPMENT. IF THIS
OCCURS...SNOWFALL RATES AOA 1 IN/HR MAY BE RESTRICTED TO SRN NEW
ENGLAND WITH MORE MODERATE RATES WWD. HOWEVER...BASED ON RECENT IR
CLOUD-TOP COOLING AND INCREASING RADAR REFLECTIVITY FROM CNTRL MD
INTO ERN PA...SUSPECT THE NAM MAY BE AN OUTLIER WITH RESPECT TO A
PROBABLE BURST OF HEAVY SNOW OVER ERN PA/NRN NJ/SERN NY BETWEEN
07-11Z.
..GRAMS.. 01/21/2011
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...BOX...OKX...ALY...PHI...BGM...
LAT...LON 40397500 40577575 41157576 42057489 42557335 42687158
42687080 41947056 41497083 41247192 40817314 40457442
40397500SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jan 21, 7:32 AM EST | Mesoscale Discussion | SPC | Essex, Norfolk, Plymouth, Suffolk | 5 hr |
Nearby
Mesoscale Discussions in New York, 2011Mesoscale Discussions in Massachusetts, 2011Mesoscale Discussions in New Jersey, 2011Every mesoscale discussion in 2011
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.