140  
ACUS11 KWNS 071626  
SWOMCD  
SPC MCD 071625  
MEZ000-NHZ000-MAZ000-VTZ000-CTZ000-NYZ000-NJZ000-PAZ000-072230-  
 
MESOSCALE DISCUSSION 0058  
NWS STORM PREDICTION CENTER NORMAN OK  
1025 AM CST WED FEB 07 2018  
 
AREAS AFFECTED...PENNSYLVANIA...NEW YORK...NEW ENGLAND  
 
CONCERNING...WINTER MIXED PRECIPITATION  
 
VALID 071625Z - 072230Z  
 
SUMMARY...HEAVY SNOWFALL WILL BE POSSIBLE FROM LATE THIS MORNING  
INTO THIS AFTERNOON FROM NORTHERN PENNSYLVANIA EAST NORTHEASTWARD  
ACROSS MUCH OF CENTRAL AND NORTHERN NEW YORK INTO NEW ENGLAND.  
FREEZING RAIN WILL BE LIKELY IN CENTRAL PENNSYLVANIA WITH A SNOW TO  
FREEZING RAIN TRANSITION TAKING PLACE FROM SOUTHEAST NEW YORK INTO  
SOUTHERN NEW ENGLAND LATE THIS MORNING INTO THIS AFTERNOON.  
 
DISCUSSION...THE LATEST WATER VAPOR IMAGERY SHOWS AN UPPER-LEVEL  
TROUGH OVER THE WESTERN GREAT LAKES REGION WITH STRONG WEST TO  
SOUTHWEST MID-LEVEL FLOW LOCATED ACROSS THE NORTHEAST. A 90 TO 100  
KT MID-LEVEL JET MAX IS ANALYZED BY THE RAP ACROSS THE LOWER GREAT  
LAKES. IN ADDITION, THE EXIT REGION OF A 60 TO 70 KT LOW-LEVEL JET  
IS ANALYZED ACROSS NORTHERN PENNSYLVANIA AND CENTRAL NEW YORK. THESE  
TWO FEATURES ARE ENHANCING LARGE-SCALE ASCENT ACROSS SOUTHWESTERN  
PARTS OF THE MCD AREA. IN RESPONSE, WIDESPREAD WINTER PRECIPITATION  
IS ONGOING FROM PENNSYLVANIA EAST NORTHEASTWARD INTO SOUTHERN NEW  
ENGLAND. FORECAST SOUNDINGS SUGGEST THAT THERMAL PROFILES ARE COLD  
ENOUGH FOR SNOW IN NORTHERN PENNSYLVANIA, CENTRAL NEW YORK AND  
ACROSS MUCH OF NEW ENGLAND WHERE 1 INCH PER HOUR SNOWFALL RATES WILL  
BE POSSIBLE THROUGH THIS AFTERNOON.  
 
FURTHER TO THE SOUTH ACROSS CENTRAL PENNSYLVANIA AND SOUTHERN NEW  
YORK, FORECAST SOUNDINGS SHOW A WARM LAYER NEAR 850 MB. THIS  
COMBINED WITH SURFACE TEMPERATURES NEAR OR BELOW FREEZING WILL BE  
FAVORABLE FOR FREEZING RAIN. AS THE LOW-LEVEL JET MOVES  
NORTHEASTWARD, THE WARM LAYER WILL SPREAD ACROSS SOUTHERN NEW YORK  
INTO SOUTHERN NEW ENGLAND WHERE A TRANSITION FROM SNOW TO FREEZING  
RAIN IS EXPECTED. FREEZING RAIN RATES SHOULD REACH 0.05 INCHES PER 3  
HOURS ACROSS THIS AREA.  
 
..BROYLES/HART.. 02/07/2018  
   
..PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT
 
 
ATTN...WFO...CAR...GYX...BOX...BTV...OKX...ALY...PHI...BGM...  
BUF...CTP...  
 
LAT...LON 42967091 42097230 41117504 40467716 40197804 40237844  
40567862 40827864 41657848 43157725 44327526 45197201  
45147013 44796928 44316885 43746975 42967091  
 
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