290  
FXUS61 KAKQ 211041  
AFDAKQ  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE WAKEFIELD VA  
641 AM EDT SAT APR 21 2018  
   
SYNOPSIS
 
 
COOL AND DRY CONDITIONS CONTINUE THROUGH THE WEEKEND AS HIGH  
PRESSURE IS CENTERED FROM THE GREAT LAKES TO THE MID ATLANTIC  
REGION. LOW PRESSURE WILL TRACK FROM THE GULF COAST STATES  
NORTHEAST UP ALONG THE EAST COAST LATE MONDAY THROUGH WEDNESDAY.  
 

 
   
NEAR TERM /THROUGH TONIGHT/
 
 
AS OF 350 AM EDT SATURDAY...  
 
LATEST SFC ANALYSIS SHOWS ~1032 MB BROAD HIGH PRESSURE CENTERED  
OVER THE GREAT LAKES REGION. THE HIGH CONTINUES TO EXTEND DOWN  
INTO THE MID ATLC REGION TODAY, LEADING TO ANOTHER DRY DAY WITH  
A SUNNY SKY FOLLOWING SOME EARLY MORNING PATCHY FROST. HIGH  
TEMPS IN THE MID 60S MOST AREAS EXCEPT NEAR THE COAST (UPR 50S)  
WHERE SEA BREEZES MAY DEVELOP THIS AFTN.  
 
FOR TONIGHT...THE FA REMAINS UNDER THE INFLUENCE OF SFC HIGH  
PRESSURE CENTERED OFF TO THE NORTH. SOME INCREASING MOISTURE IN  
THE WNW FLOW ALOFT WILL ALLOW FOR INCREASING CLOUDS AND TEMPS TO  
ONLY FALL INTO THE LOW/MID 40S.  
 

 
   
SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/
 
 
AS OF 350 AM EDT SATURDAY...  
 
HIGH PRESSURE SLIDES OFFSHORE SUNDAY INTO SUNDAY NIGHT. THIS  
WILL BRING GRADUALLY INCREASING CLOUDS SUNDAY AFTERNOON AND  
NIGHT. HIGHS SUNDAY RANGE THROUGH THE 60S. N OR NE WINDS 10 KT  
OR LESS SUNDAY MORNING VEER AROUND TO THE SE SUNDAY NIGHT,  
BRINGING GRADUALLY MODERATING TEMPS.  
 
BY MONDAY MORNING, NEXT WEATHER SYSTEM CURRENTLY OVER THE DESERT  
SOUTHWEST WILL HAVE PUSHED EAST TOWARD THE GULF COAST REGION.  
MODELS ARE IN GENERAL AGREEMENT THAT THE TROUGH WILL GRADUALLY  
DAMPEN, WITH THE CLOSED LOW OPENING UP AS THE UPPER TROUGH  
TRAVERSES THE SOUTHERN TIER OF STATES OVER THE WEEKEND, WITH A  
WEAK INVERTED TROUGH DEVELOPING OVER THE SOUTHEAST INTO MONDAY  
MORNING. GIVEN THE ANTECEDENT DRY CONDITIONS AND THE SLOW  
EVOLUTION OF THIS SYSTEM, HAVE KEPT MONDAY DRY ACROSS THE LOCAL  
AREA, DESPITE INCREASE IN CLOUDINESS. MAY BE A FEW LIGHT RAIN  
SHOWERS POSSIBLE ACROSS THE I-85 CORRIDOR, BUT WILL HOLD POPS AT  
SLIGHT CHC OR LESS. MORE CLOUDS THAN SUN OVER MUCH OF THE AREA  
WILL KEEP TEMPS IN THE MID 60S. RAIN CHANCES STEADILY INCREASE  
MONDAY NIGHT ACROSS THE PIEDMONT, WITH PRECIP SPREADING NNE INTO  
THE AREA INTO TUESDAY MORNING. LOWS MAINLY IN THE UPPER 40S IN  
THE PIEDMONT TO LOW 50S ACROSS SE COASTAL PLAIN.  
 

 
   
LONG TERM /TUESDAY THROUGH FRIDAY/
 
 
AS OF 410 PM EDT FRIDAY...  
 
RAIN WILL MOVE INTO THE AREA FROM SSW TO NNE DURING THE DAY ON  
TUESDAY AS THE UPPER WAVE AND ASSOCIATED SFC LOW PRES PUSH E/NE.  
20/12Z GFS/ECMWF/CMC ARE IN GOOD AGREEMENT THAT THE AREA OF LIGHT TO  
MODERATE RAIN WILL COVER THE ENTIRE CWA BY LATE AFTERNOON ON TUESDAY  
AND LAST THROUGH AROUND 12Z WED. GIVEN THE AGREEMENT BETWEEN THE  
MOST RECENT SUITE OF GUIDANCE, HAVE INCREASED POPS TO 60-70% FOR THE  
ENTIRE CWA TUE-EARLY WED. DUE TO THE RAIN, HIGH TEMPERATURES WILL BE  
BE IN THE LOW 60S FOR THE BULK OF THE CWA ON TUESDAY. AFTER THE SFC  
LOW TRACKS THROUGH EASTERN PORTIONS OF THE CWA WED AM, THE MAIN AREA  
OF RAIN WILL EXIT THE REGION. A FEW SHOWERS WILL STILL BE POSSIBLE  
DURING THE DAY, BUT TEMPERATURES SHOULD WARM TO NEAR 70 ON WEDNESDAY  
IF THE RAIN EXITS EARLY ENOUGH (THIS LOOKS MORE LIKELY IN SOUTHERN  
PARTS OF THE CWA).  
 
12Z GFS/CMC TRACK ANOTHER SFC LOW/WEAK COLD FRONT THROUGH THE AREA  
THURSDAY-FRIDAY AM, BUT ECMWF DOES NOT HAVE A RAINY SOLUTION. THUS,  
HAVE KEPT POPS AT OR BELOW 40%. HIGHS AROUND 70/LOWS BETWEEN 50-55  
EXPECTED THU-FRI. AN UPPER TROUGH AMPLIFIES OVER THE EASTERN US  
FRIDAY PM INTO NEXT WEEKEND AS SFC LOW PRESSURE IS FORECAST TO  
DEEPEN OVER THE NORTHEASTERN US AT THE SAME TIME. THIS WILL SET THE  
STAGE FOR ANOTHER CHANCE OF RAIN LATE FRIDAY AS WELL AS BELOW  
AVERAGE TEMPERATURES NEXT WEEKEND.  
 

 
   
AVIATION /12Z SATURDAY THROUGH WEDNESDAY/
 
 
AS OF 640 AM EDT SATURDAY...  
 
VFR THROUGH THE 12Z TAF PERIOD. WINDS TODAY WILL REMAIN LIGHT  
AT LESS THAN 10 KT, GENLY FROM THE N BUT WILL SHIFT ONSHORE TO  
THE E/NE NEAR THE COAST IN THE AFTN. EXPECT SKC THROUGH MOST OF  
THE TAF PERIOD FOR ALL TERMINALS (SOME HIGH CLOUDS INCREASING  
LATE).  
 
OUTLOOK: VFR CONDITIONS WILL CONTINUE SUN, WITH HIGH PRESSURE  
OVER THE REGION. A DISTURBANCE APPROACHES THE REGION LATE MONDAY  
AND TUESDAY BRINGING THE NEXT CHANCE FOR FLIGHT RESTRICTIONS  
AND RAIN.  
 

 
   
MARINE
 
 
AS OF 350 AM EDT SATURDAY...  
 
A WEAK COLD FRONT IS DROPPING N-S ACROSS THE MARINE AREA EARLY  
THIS MORNING. THE WIND WILL BECOME NE AND BRIEFLY INCREASE TO  
15-20KT IMMEDIATELY BEHIND THE COLD FRONT MAINLY OVER THE  
BAY/OCEAN AND POSSIBLY THE LOWER JAMES. THE DURATION WILL ONLY  
BE 1-2HRS, SO THIS WILL BE HANDLED WITH AN MWS OVER THE BAY.  
WAVES IN THE BAY COULD ALSO INCREASE TO 2-3FT. OTHERWISE, HIGH  
PRESSURE WILL PREVAIL OVER THE REGION TODAY AND SUNDAY RESULTING  
IN BENIGN MARINE CONDITIONS. THE WIND WILL BECOME SEA/BAY  
BREEZE DRIVEN BY THIS AFTN, THE S/SE 5-10KT TONIGHT, BEFORE  
BECOMING N SUNDAY MORNING THEN E 10KT BY SUNDAY AFTN AS HIGH  
PRESSURE SHIFTS TOWARD NEW ENGLAND AND LOW PRESSURE MOVES INTO  
THE DEEP SOUTH. HIGH PRESSURE PUSHES OFF THE SRN NEW ENGLAND  
COAST EARLY NEXT WEEK AS LOW PRESSURE MOVES OFF THE SOUTHEAST  
COAST. THIS WILL RESULT IN INCREASING ONSHORE FLOW. AN E WIND IS  
EXPECTED TO REACH 10-15KT BY MONDAY, AND THEN 15-25KT BY MONDAY  
NIGHT/TUESDAY/TUESDAY NIGHT. ONSHORE FLOW WILL RESULT IN SEAS  
BUILDING TO 6-10FT TUESDAY/TUESDAY NIGHT, WITH 4-5FT WAVES IN  
THE MOUTH OF THE BAY (2-4FT ELSEWHERE IN THE BAY). BROAD LOW  
PRESSURE CROSSES THE REGION WEDNESDAY WITH THE WIND BECOMING NW  
IN THE WAKE OF THE LOW.  
 

 
   
AKQ WATCHES/WARNINGS/ADVISORIES
 
 
MD...NONE.  
NC...NONE.  
VA...NONE.  
MARINE...NONE.  
 

 
 

 
SYNOPSIS...MAS  
NEAR TERM...MAS  
SHORT TERM...MAS/MAM  
LONG TERM...ERI  
AVIATION...LKB/MAS  
MARINE...AJZ  
 
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