Mesoscale Discussion 1741

Issued

Aug 11, 2012, 12:56 PM EDT (16:56 UTC)

Expired

Aug 11, 2012, 2:30 PM EDT

In force

94 min

Issued by

the Storm Prediction Center

Chance of a watch

20%

The Albany radar (KENX), 54 km from the middle of the area, began a volume at 16:57 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.

609 
ACUS11 KWNS 111656
SWOMCD
SPC MCD 111656 
MAZ000-NHZ000-RIZ000-CTZ000-VTZ000-NYZ000-111830-

MESOSCALE DISCUSSION 1741
NWS STORM PREDICTION CENTER NORMAN OK
1156 AM CDT SAT AUG 11 2012

AREAS AFFECTED...ERN NEW YORK STATE INTO PARTS OF WRN AND SRN NEW
ENGLAND

CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY 

VALID 111656Z - 111830Z

PROBABILITY OF WATCH ISSUANCE...20 PERCENT

SUMMARY...THUNDERSTORM ACTIVITY IS EXPECTED TO PERSIST AND INCREASE
IN COVERAGE WHILE DEVELOPING NORTHWARD ACROSS THE REGION THROUGH
18-21Z.  THE NEED FOR A WATCH IS NOT ANTICIPATED AT THE PRESENT
TIME...AS THE ENVIRONMENT IS EXPECTED TO REMAIN MARGINAL FOR AN
ORGANIZED SEVERE WEATHER EVENT...BUT TRENDS WILL CONTINUE TO BE
MONITORED.

DISCUSSION...AN INCREASE IN THUNDERSTORM ACTIVITY IS NOW WELL
UNDERWAY ACROSS THE CATSKILLS AND HUDSON VALLEY AREA INTO SOUTHERN
NEW ENGLAND.  THIS IS OCCURRING WHERE INHIBITION IS RELATIVELY WEAK
EAST OF THE CLOSED MID-LEVEL LOW NOW BEGINNING TO LIFT THROUGH
SOUTHEAST ONTARIO.  AN IMPULSE PIVOTING AROUND THE EASTERN PERIPHERY
OF THIS CIRCULATION MAY BE CONTRIBUTING TO LARGE-SCALE UPWARD
VERTICAL MOTION...WHICH PROBABLY WILL CONTRIBUTE TO ADDITIONAL STORM
DEVELOPMENT ACROSS THE ADIRONDACKS AND CHAMPLAIN VALLEY DURING THE
NEXT FEW HOURS.

THIS IS OCCURRING IN THE PRESENCE OF STRONGLY SHEARED 40-50 KT
SOUTHERLY DEEP LAYER MEAN FLOW...THOUGH STRONGER WIND FIELDS ARE
GENERALLY CONFINED TO MID/UPPER-LEVELS.  WITH THE MID-LEVEL COLD
CORE OF THE UPPER LOW REMAINING WELL TO THE NORTH AND WEST OF THE
REGION...THERMODYNAMIC PROFILES APPEAR GENERALLY CHARACTERIZED BY
SOMEWHAT WARM MID-LEVELS WITH WEAK LAPSE RATES.  BREAKS IN CLOUD
COVER ARE ALLOWING FOR POCKETS OF INSOLATION...BUT LAPSE RATES IN
THE RELATIVELY MOIST LOW-LEVELS PROBABLY WILL REMAIN RATHER MODEST
AS WELL.  SO...WHILE VERTICAL SHEAR IS SUFFICIENT FOR MID-LEVEL
UPDRAFT ROTATION AND ORGANIZED CONVECTIVE DEVELOPMENT... SEVERE HAIL
POTENTIAL STILL APPEARS RELATIVELY LOW.  SEVERE WIND POTENTIAL
REMAINS A BIT MORE UNCLEAR...BUT ANY DAMAGING WIND GUSTS ARE
CURRENTLY ANTICIPATED TO REMAIN SOMEWHAT SPOTTY IN COVERAGE.

..KERR/HART.. 08/11/2012

...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...

ATTN...WFO...GYX...BOX...BTV...OKX...ALY...BGM...BUF...

LAT...LON   44077591 44877549 44707226 43757224 42967140 42177100
            41267272 41267444 41707459 42387477 43177483 44077591

Mesoscale Discussions in New York, 2012Mesoscale Discussions in Vermont, 2012Mesoscale Discussions in Connecticut, 2012Every mesoscale discussion in 2012

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.