016  
ACUS02 KWNS 221729  
SWODY2  
SPC AC 221728  
 
DAY 2 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK  
1128 AM CST MON JAN 22 2018  
 
VALID 231200Z - 241200Z  
 
...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS  
OF THE MID-ATLANTIC...  
   
..SUMMARY
 
 
THUNDERSTORMS ARE POSSIBLE FROM PORTIONS OF THE MID-ATLANTIC INTO  
SOUTHERN NEW ENGLAND TUESDAY MORNING THROUGH TUESDAY AFTERNOON AND  
ACROSS THE SOUTHERN FLORIDA PENINSULA TUESDAY AFTERNOON. A COUPLE  
STORMS ACROSS THE MID-ATLANTIC MAY PRODUCE GUSTY WINDS AND PERHAPS A  
BRIEF TORNADO TUESDAY MORNING.  
   
..SYNOPSIS
 
 
A RATHER EXPANSIVE CLOSED MID-LEVEL LOW WILL CONTINUE ITS  
EAST/NORTHEASTWARD PROGRESSION EARLY TUESDAY, GRADUALLY OPENING AS  
IT LIFTS INTO THE ST. LAWRENCE VALLEY. CONCURRENTLY, AN OCCLUDED  
SURFACE LOW WILL ADVANCE ACROSS SOUTHERN ONTARIO AND QUEBEC. TO ITS  
SOUTH/SOUTHEAST, A FRONT WILL SWEEP EASTWARD ACROSS THE MID-ATLANTIC  
AND SOUTHEAST, USHERING IN A CONTINENTAL AIR MASS THROUGH THE DAY.  
   
..MID-ATLANTIC
 
 
AHEAD OF THE FRONT, SOUTHERLY FLOW WILL TRANSPORT SURFACE DEW POINTS  
IN THE UPPER 50S/LOWER 60S NORTHWARD ACROSS THE MID-ATLANTIC LATE  
TONIGHT. WHILE MOIST LOW-LEVEL PROFILES INITIALLY IN THE MORNING  
(PRIOR TO FRONTAL PASSAGE) WILL KEEP SURFACE-BASED BUOYANCY LOW  
(GENERALLY LESS THAN 500 J/KG), SOUTH/SOUTHWESTERLY FLOW WILL  
INCREASE CONSIDERABLY ABOVE THE SURFACE (E.G., 850MB FLOW AROUND  
55-65 KT). FORCING FOR ASCENT ASSOCIATED WITH THE LARGER-SCALE  
TROUGH, IN ADDITION TO A NOSE OF STRENGTHENING WARM-AIR ADVECTION  
LIFTING NORTH OVER THE MID-ATLANTIC, SHOULD FOSTER SMALL CONVECTIVE  
BANDS ACCELERATING EAST TOWARDS THE COAST THROUGH THE MORNING HOURS.  
WHILE MOST UPDRAFTS WILL LIKELY BE TOO WEAK/DISORGANIZED TO YIELD A  
SEVERE THREAT, FORECAST SOUNDINGS INDICATE ENOUGH POTENTIAL FOR A  
FEW STRONGER SURFACE-BASED UPDRAFTS. CONSIDERING THE STRENGTH OF  
LOW-LEVEL SHEAR AND OVERALL FLOW, SUCH CONVECTIVE ELEMENTS MAY YIELD  
LOCALIZED INSTANCES OF GUSTY/DAMAGING WINDS AND PERHAPS A BRIEF  
TORNADO TUESDAY MORNING. IN TURN, MARGINAL PROBABILITIES HAVE BEEN  
INTRODUCED FOR PARTS OF THE REGION.  
 
..PICCA.. 01/22/2018  
 

 
 
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