Severe Storm Outlook Narrative (AC)
Issued by NWS

Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
000
ACUS11 KWNS 202332
SWOMCD
SPC MCD 202331
NYZ000-PAZ000-210200-

MESOSCALE DISCUSSION 0407
NWS STORM PREDICTION CENTER NORMAN OK
0631 PM CDT MON APR 20 2015

AREAS AFFECTED...PORTIONS OF S-CNTRL NY AND NERN PA

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE

VALID 202331Z - 210200Z

PROBABILITY OF WATCH ISSUANCE...40 PERCENT

SUMMARY...PORTIONS OF S-CNTRL NY AND NERN PA ARE BEING MONITORED FOR
THE POSSIBLE ISSUANCE OF A NEW WW...AS THE RISK FOR SVR TSTMS
POTENTIALLY SPREADS NEWD ACROSS THE REGION INTO THE EVENING.

DISCUSSION...ONGOING SCATTERED CONVECTION ACROSS PORTIONS OF CNTRL
PA INTO SWRN NY WILL CONTINUE TO SPREAD NEWD DURING THE EVENING
HOURS. WHILE NOCTURNAL COOLING WILL AID SOME STABILIZATION OF THE
PBL...THE PERSISTENCE OF COLD MID-LEVEL TEMPERATURES AND LARGE-SCALE
MID-LEVEL HEIGHT FALLS/ASCENT SUGGEST SOME RISK THAT STRONG
CONVECTION WILL EXTEND NEWD WITH TIME. CCX AND BGM VWPS SAMPLE A
VERTICALLY VEERING WIND PROFILE WITH 45-50 KT OF MID-LEVEL SWLYS
CAPABLE OF MAINTAINING ORGANIZED SMALL QUASI-LINEAR SEGMENTS AND
PERHAPS SUPERCELLS WITH DMGG WIND GUSTS AND POSSIBLY ONE OR TWO
SHORT-LIVED TORNADOES. MARGINAL INSTABILITY WITH LIMITED LOW-LEVEL
MOISTURE COULD BE DETERRENTS TO A MORE ROBUST SVR-TSTM POTENTIAL.
HOWEVER...THE ADEQUATE VERTICAL SHEAR AND RELATED STORM-INDUCED
PERTURBATION PRESSURE DEFICITS ALOFT MAY OFFSET NOCTURNAL
STABILIZATION IN SUPPORTING A SVR RISK. AS SUCH...THE AREA WILL
CONTINUE TO BE MONITORED FOR POSSIBLE WW ISSUANCE.

..COHEN/CORFIDI.. 04/20/2015

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

ATTN...WFO...BGM...BUF...

LAT...LON   42017660 42417766 43077663 42657512 41967483 41437501
            41437578 42017660



USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.