197  
ACUS11 KWNS 110815  
SWOMCD  
SPC MCD 110815  
MEZ000-111215-  
 
MESOSCALE DISCUSSION 2259  
NWS STORM PREDICTION CENTER NORMAN OK  
0215 AM CST WED DEC 11 2024  
 
AREAS AFFECTED...SOUTHERN MAINE  
 
CONCERNING...FREEZING RAIN  
 
VALID 110815Z - 111215Z  
 
SUMMARY...LIGHT TO MODERATE FREEZING RAIN APPEARS LIKELY THROUGH 12  
UTC ACROSS PARTS OF SOUTHERN MAINE.  
 
DISCUSSION...RECENT SURFACE OBSERVATIONS FROM SOUTHERN ME HAVE  
REPORTED A WINTRY MIX OF LIGHT FREEZING RAIN AND SNOW OVER THE PAST  
HOUR AS LIGHT PRECIPITATION MIGRATES OVER THE REGION. THE 00 UTC GYX  
SOUNDING SAMPLED SUB-FREEZING SURFACE TEMPERATURES IN THE UPPER 20S  
WITH A 2 C WARM NOSE AT AROUND 850 MB. THIS WARM NOSE IS EXPECTED TO  
INTENSIFY THROUGH 12 UTC, AMID STRENGTHENING LOW TO MID-LEVEL WARM  
AIR ADVECTION, WITHIN THE WARM CONVEYOR BELT OF AN INTENSIFYING  
CYCLONE. THIS SHOULD PROMOTE A CHANGE OVER FROM A WINTRY MIX TO  
PREDOMINANTLY LIQUID HYDROMETEORS OVER THE NEXT COUPLE OF HOURS.  
 
LATEST SURFACE ANALYSES/OBSERVATIONS SHOW THE SURFACE WARM FRONT  
REMAINS WELL DISPLACED TO THE SOUTH, SO THE SHALLOW SUB-FREEZING  
LAYER SHOULD REMAIN IN PLACE THROUGH SUNRISE. LIGHT PRECIPITATION  
SHOULD CONTINUE AS ISENTROPIC ASCENT INCREASES, BUT PRECIPITATION  
RATES WILL INCREASE CLOSER TO 10-12 UTC AS A BROADER PLUME OF  
STRATIFORM RAIN (ASSOCIATED WITH DEEPER LARGE-SCALE ASCENT AND  
CLOSER TO THE SURFACE WARM FRONT) MIGRATES FROM NEW ENGLAND  
NORTHEAST INTO SOUTHERN ME. IT REMAINS UNCLEAR HOW SURFACE  
TEMPERATURES WILL RESPOND AS THIS PRECIPITATION APPROACHES, GIVEN  
THE COINCIDENT ARRIVAL OF THE SURFACE WARM FRONT. HOWEVER, LATEST  
HIGH-RES GUIDANCE SUGGESTS THE SUB-FREEZING LAYER WILL PERSIST LONG  
ENOUGH TO REALIZE MODERATE FREEZING RAIN RATES BETWEEN 10-12 UTC,  
ESPECIALLY WITHIN DEEPER VALLEYS.  
 
..MOORE.. 12/11/2024  
   
..PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT
 
 
ATTN...WFO...CAR...GYX...  
 
LAT...LON 43927097 44437066 44847012 45106936 45156876 45096831  
44936819 44696829 44626860 44386910 43996980 43727015  
43517051 43487072 43547087 43647093 43927097  
 
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