885  
FXUS61 KLWX 210750  
AFDLWX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC  
250 AM EST SAT DEC 21 2024  
   
SYNOPSIS
 
 
LINGERING SNOW SHOWERS IN THE ALLEGHENIES, WITH SOME FLURRIES  
POSSIBLE EAST OF THE MOUNTAINS TODAY. STRONG CANADIAN HIGH PRESSURE  
BUILDS IN THROUGH MONDAY, WITH DRY AND VERY COLD CONDITIONS.  
PRECIPITATION CHANCES INCREASE AS ANOTHER FRONT APPROACHES DURING  
THE MIDDLE OF NEXT WEEK.  
 

 
   
NEAR TERM /THROUGH TONIGHT/
 
 
REINFORCING UPPER TROUGHING CONTINUES ACROSS THE MID-ATLANTIC TODAY  
AS A STRONG CANADIAN HIGH BEGINS TO BUILD SOUTH INTO THE REGION.  
MOUNTAIN SNOW SHOWERS CONTINUE THROUGH THE AFTERNOON, WITH SOME  
PERIODS OF HEAVIER SHOWERS LIKELY AT TIMES. THESE STREAMERS WILL  
RESULT IN SOME ISOLATED AREAS PICKING UP HIGHER SNOW TOTALS. SNOW  
TOTALS RANGE FROM 1-3", WITH UP TO 4" POSSIBLE IN SOME AREAS THAT  
REPEATED STREAMERS/HEAVIER SNOW SHOWERS. EAST OF THE MOUNTAINS,  
DYNAMICS BECOME MOST FAVORABLE FOR SCATTERED SNOW SHOWERS EAST  
TOWARD THE BLUE RIDGE IN THE AFTERNOON. IF A MORE PERSISTENT  
STREAMER DOES MANAGE TO SET UP, THERE COULD BE SOME VERY LIGHT  
ACCUMULATION, OTHERWISE NOT EXPECTING SNOW TO STICK. EAST OF THE  
BLUE RIDGE, SOME FLURRIES ARE CERTAINLY POSSIBLE THIS AFTERNOON.  
 
ASIDE FROM SNOW, IT WILL BE DOWNRIGHT COLD AS BLUSTERY CONDITIONS  
DEVELOP THIS MORNING INTO THIS EVENING. WINDS GUST AROUND 25-35 MPH,  
WITH UP TO 40 MPH IN THE MOUNTAINS. COMBINED WITH HIGHS IN THE 30S,  
THE RESULTING WIND CHILL VALUES DURING THE MIDDLE OF THE DAY ARE  
LIKELY TO BE IN THE TEENS TO 20S, WITH SINGLE DIGITS IN THE  
MOUNTAINS. BRISK TO BLUSTERY CONDITIONS CONTINUE TONIGHT, AS LOWS  
DROP TO THE MID TO UPPER TEENS. THE RESULT IS WIND CHILLS IN THE  
SINGLE DIGITS TO LOW TEENS, WITH BELOW 0 VALUES IN THE ALLEGHENIES.  
 

 
   
SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/
 
 
STRONG CANADIAN HIGH CONTINUES ITS MARCH ACROSS THE EASTERN U.S.  
THROUGH THE START OF NEXT WEEK. WELL BELOW NORMAL TEMPERATURES  
SUNDAY AS HIGH STRUGGLE TO REACH FREEZING, AND LINGERING WIND GUSTS  
OF 15-20 MPH MAKE FOR A VERY COLD AFTERNOON. SUNDAY NIGHT BRINGS  
LOWS IN THE SINGLE DIGITS TO LOWER TEENS FOR MOST. MONDAY IS NOT  
QUITE AS COLD, THOUGH STILL BELOW NORMAL WITH HIGHS IN THE 30S.  
CLOUDS BUILD IN THROUGHOUT THE DAY AS A WEAK CLIPPER APPROACHES FROM  
THE NORTHWEST. THIS COULD BRING SOME SNOW SHOWER TO THE ALLEGHENIES  
AND ALONG/NORTH OF I-70 LATE MONDAY NIGHT.  
 

 
   
LONG TERM /TUESDAY THROUGH FRIDAY/
 
 
A COLD FRONT, ASSOCIATED WITH A LOW PRESSURE SYSTEM TRACKING TO OUR  
NORTH, WILL BRING A CHANCE TO SLIGHT CHANCE OF A RAIN/SNOW MIX AS IT  
MOVES THROUGH THE FORECAST AREA ON TUESDAY. HIGHEST PRECIPITATION  
CHANCES ARE ALONG AND WEST OF THE ALLEGHENIES WITH MOUNTAIN SNOW  
SHOWERS EXPECTED THROUGHOUT THE DAY. THOSE ALONG THE I-81 CORRIDOR  
AND SOUTH OF I-66 WILL LIKELY STAY DRY THROUGHOUT THE DAY.  
CONDITIONS DRY OUT OVERNIGHT AREAWIDE WITH PRECIPITATION CHANCES  
RETURNING WEDNESDAY AFTERNOON AS THE FRONTAL BOUNDARY REMAINS  
NEARBY. OVERALL, POPS REMAIN LOW (NEAR OR BELOW 30%) THROUGH FRIDAY  
WITH MODERATING TEMPERATURES LEADING TO RAIN BEING THE PRIMARY  
PRECIPITATION TYPE SHOULD SHOWERS OCCUR. AS TEMPERATURES FALL  
THURSDAY NIGHT, BRIEF SNOW SHOWERS ARE POSSIBLE AT HIGHER  
ELEVATIONS.  
 
TEMPERATURES MODERATE THROUGHOUT THE LONG TERM PERIOD WITH  
TEMPERATURES SLOWLY RISING EACH DAY. HIGH TEMPERATURES WILL BE IN  
THE 30S AND 40S EACH DAY WITH OVERNIGHT LOWS IN THE 20S AND 30S.  
 

 
   
AVIATION /08Z SATURDAY THROUGH WEDNESDAY/
 
 
VFR CONDITIONS EXPECTED THROUGH MONDAY AS A STRONG CANADIAN HIGH  
BUILDS ACROSS THE REGION. THE MAIN AVIATION IMPACT TODAY IS GOING TO  
BE FROM STRONG NORTHWEST WIND GUSTS. WINDS BEGIN TO INCREASE EARLY  
THIS MORNING, THEN PEAK LATE MORNING TO EARLY AFTERNOON WITH GUSTS  
AROUND 25-30 KNOTS. WINDS SLOWLY DIMINISH TONIGHT INTO SUNDAY. A FEW  
FLURRIES OR LIGHT SNOW SHOWERS ARE POSSIBLE AT MRB TODAY, THOUGH  
CONFIDENCE IN WHERE THESE COULD OCCUR IS TOO LOW TO INCLUDE IN TAF  
AT THIS TIME. SOME FLURRIES POSSIBLE AT OTHER TERMINALS TOO.  
 
SUB-VFR CONDITIONS ARE POSSIBLE TUESDAY AND WEDNESDAY AS A FRONTAL  
BOUNDARY MOVES THROUGH THE FORECAST AREA. LIGHT AND VARIABLE WINDS  
ARE EXPECTED BOTH DAYS.  
 

 
   
MARINE
 
 
HAZARDOUS MARINE CONDITIONS EXPECTED TO DEVELOP LATER THIS MORNING  
AS A STRONG CANADIAN HIGH PRESSURE BUILDS ACROSS THE REGION. PEAK  
WIND GUSTS WILL BE AROUND 25-30 KNOTS ACROSS THE WATERS, WITH  
OCCASIONAL GUSTS NEAR GALE-FORCE POSSIBLE IN THE OPEN CHESAPEAKE BAY  
WATERS. WINDS SLOWLY DIMINISH THIS EVENING, BUT REMAIN IN SCA LEVELS  
THROUGH SUNDAY AFTERNOON. WINDS ARE FORECAST TO FALL BELOW 10 KNOTS  
SUNDAY NIGHT INTO MONDAY.  
 
WINDS ARE EXPECTED TO STAY BELOW SCA CRITERIA TUESDAY AND WEDNESDAY.  
 

 
   
LWX WATCHES/WARNINGS/ADVISORIES
 
 
DC...NONE.  
MD...NONE.  
VA...NONE.  
WV...NONE.  
MARINE...SMALL CRAFT ADVISORY UNTIL 10 AM EST SUNDAY FOR ANZ530>532-536-  
538>540-542.  
SMALL CRAFT ADVISORY UNTIL 4 PM EST SUNDAY FOR ANZ533-534-537-  
541-543.  
SMALL CRAFT ADVISORY UNTIL 9 PM EST THIS EVENING FOR ANZ535.  
 

 
 

 
 
SYNOPSIS...KRR  
NEAR TERM...KRR  
SHORT TERM...KRR  
LONG TERM...AVS  
AVIATION...KRR/AVS  
MARINE...KRR/AVS  
 
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