Alert archive / New York / Mesoscale Discussions in 2012
Mesoscale Discussion 18
The Storm Prediction Center issued this mesoscale discussion at Jan 13, 2012, 10:42 AM EST for 7 counties in New York. It was in force for 4 hr.
The area
The outline as issued.
The facts
- Issued
- Jan 13, 2012, 10:42 AM EST (15:42 UTC)
- Expired
- Jan 13, 2012, 2:45 PM EST
- In force
- 4 hr
- Issued by
- the Storm Prediction Center
Counties Hamilton County, NY, Herkimer County, NY, Jefferson County, NY, Lewis County, NY, Oneida County, NY, Oswego County, NY, St. Lawrence County, NY
The radar
The Ft Drum radar (KTYX), 42 km from the middle of the area, began a volume at 15:43 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, 3.7 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
- 471 m above ground
- 0-6 km bulk shear
- 94 kt
- 0-1 km storm-relative helicity
- 416 m²/s²
- 0-3 km storm-relative helicity
- 509 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
917
ACUS11 KWNS 131542
SWOMCD
SPC MCD 131542
NYZ000-131945-
MESOSCALE DISCUSSION 0018
NWS STORM PREDICTION CENTER NORMAN OK
0942 AM CST FRI JAN 13 2012
AREAS AFFECTED...TUG HILL PLATEAU AND WRN ADIRONDACKS OF NY
CONCERNING...HEAVY SNOW
VALID 131542Z - 131945Z
SNOWFALL RATES NEAR 1 INCH PER HR WILL SHIFT NWD INTO PARTS OF THE
TUG HILL PLATEAU AND THE WRN ADIRONDACKS OF NY.
ADDITIONALLY...SUSTAINED WIND SPEEDS AOA 20 MPH COULD CREATE LOCALLY
REDUCED VISIBILITIES.
RADAR IMAGERY AND 1500Z METARS SHOW WIDESPREAD AREAS OF MODERATE TO
HEAVY SNOW ONGOING ACROSS MOST OF WRN/CNTRL UPSTATE NY. THIS IS
OCCURRING WITHIN A DEFORMATION ZONE N OF A CLOSED MIDLEVEL CYCLONE
MOVING NEWD ACROSS PA. AN ATTENDANT MIDLEVEL DRY SLOT /NOTED ON
WATER VAPOR LOOP/ IS SHIFTING N/EWD TOWARDS THE NY/PA BORDER AND
SHOULD RESULT IN A REPOSITIONING OF THE HEAVIEST SNOW BANDS FARTHER
N TOWARDS THE TUG HILL PLATEAU AND WRN ADIRONDACKS OF NY. SNOWFALL
RATES ARE FORECAST TO GRADUALLY DECREASE COINCIDENT WITH WEAKENING
DEEP-LAYER ASCENT/LOW-LEVEL FRONTOGENESIS THIS AFTERNOON...AND THIS
TREND HAS ALREADY BEEN NOTED IN RADAR REFLECTIVITY N/E OF KBGM OVER
THE PAST HR. SOME LAKE EFFECT ENHANCEMENT DOWNWIND OF LAKE ONTARIO
COULD RESULT IN LOCALLY HIGHER SNOWFALL RATES /WITH 30 KTS OF 0-1 KM
LAYER WLY FLOW PER BGM/ENX VWP DATA/...BUT THERMODYNAMIC PROFILES
/WITH A SHALLOW INVERSION LAYER POSITIONED NEAR 1 KM AGL PER
NAMKF/RUC40 FORECAST SOUNDINGS/ ARE NOT SUPPORTIVE FOR HIGH SNOWFALL
RATES. LATER THIS AFTERNOON...1300Z RUC40 GUIDANCE SHOWS MODEST
MIDLEVEL ISENTROPIC ASCENT CONTINUING IN THE WAKE OF THE UPPER WAVE
PASSAGE AND COULD SUPPORT LOCALLY MODERATE SNOWFALL RATES THROUGH
THIS AFTERNOON. VISIBILITIES WILL LIKELY BE REDUCED IN AREAS
EXPERIENCING HEAVY SNOWFALL WITH SUSTAINED WINDS AOA 20 MPH.
..ROGERS.. 01/13/2012
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...BTV...ALY...BGM...BUF...
LAT...LON 43207427 43017465 43167604 43597642 44057637 44297605
44677547 44767508 44427417 43927410 43207427Nearby
Mesoscale Discussions in New York, 2012Every mesoscale discussion in 2012
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.