163  
FXUS61 KAKQ 290157  
AFDAKQ  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE WAKEFIELD VA  
957 PM EDT WED JUN 28 2017  
   
SYNOPSIS
 
 
HIGH PRESSURE WILL RESIDE OFF THE MID ATLANTIC COAST TONIGHT  
THROUGH FRIDAY. A TROUGH OF LOW PRESSURE WILL SET UP OVER THE  
AREA FOR LATE FRIDAY NIGHT THROUGH SATURDAY.  
 

 
   
NEAR TERM /UNTIL 6 AM THURSDAY MORNING/
 
 
UPDATE...HIGH CLOUDS HAVE CLEARED THE AREA AS HIGH PRESSURE  
RESIDES JUST OFF THE MID ATLANTIC COAST THIS EVENING.  
TEMPERATURES ARE COOLING OFF NICELY AS A RESULT AND STILL  
ANTICIPATE LOWS IN THE UPPER 50S NW TO MID 60S SE. HIGH CLOUDS  
WILL RETURN OVERNIGHT AS WESTERLY FLOW ALOFT ALLOWS FOR  
RE-GENERATION OF LEESIDE CIRRUS. ADDITIONAL (ALBEIT WEAK)  
SUPPORT FROM SHORTWAVE ENERGY/MOISTURE PASSING ACROSS NRN VA  
SHOULD FOCUS THE CIRRUS ACROSS THE NRN HALF OF THE FORECAST  
AREA.  
 

 
   
SHORT TERM /6 AM THURSDAY MORNING THROUGH SATURDAY/
 
 
THE HIGH WILL CONTINUE TO SLIDE OUT TO SEA LATER THU THRU FRI.  
DRY WX WILL PREVAIL THRU AT LEAST THE FIRST PART OF FRI FOR THE  
ENTIRE REGION. SSW FLOW WILL START TO INCREASE ON THU  
RESULTING IN A WARMER AND SLIGHTLY MORE HUMID AIRMASS. MOSTLY  
SUNNY WITH HIGHS IN THE MID TO UPPER 80S. MOSTLY CLEAR THU NIGHT  
WITH LOWS IN THE MID TO UPPER 60S.  
 
THAT SSW FLOW WILL BRING INCREASING DEWPTS/LOW LEVEL MOISTURE  
INTO THE REGION FOR FRI THRU SAT. AN ISOLATED SHOWER OR TSTM  
COULD AFFECT SRN THIRD OF THE AREA FRI AFTN INTO FRI NIGHT.  
THEN, ISOLATED TO SCTD SHOWERS OR TSTMS WILL BE POSSIBLE SAT  
AFTN INTO SAT EVENING, AS A TROUGH OF LOW PRESSURE SETS UP OVER  
THE REGION. HIGHS ON FRI WILL RANGE FM THE MID 80S TO LOWER 90S.  
LOWS FRI NIGHT MAINLY IN THE LOWER 70S. HIGHS ON SAT IN THE  
UPPER 80S TO LOWER 90S.  
 

 
   
LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/
 
 
LONG TERM PERIOD WILL FEATURE A FAIRLY TYPICAL SUMMERTIME PATTERN  
WITH A COLD FRONT WEAKENING NEAR OR JUST N OF THE AREA SAT NIGHT/SUN  
MORNING. STILL CAPPING POPS AT 20-40% SAT NIGHT (HIGHEST N) AS  
MORE SIGNIFICANT FORCING STAYS NW CLOSER TO THE DECAYING FRONT.  
SUNDAY WILL SEE THE FRONT WASH OUT ACROSS THE LOCAL AREA, WILL  
MAINTAIN 20% POPS N/NW AND 30% POPS MOST OTHER AREAS (UP TO 40%  
OVER NORTHEAST NC). HIGHS IN THE UPPER 80S TO LOWER 90S. MON/TUE  
WILL SEE THE LOCAL AREA GENERALLY IN LIGHT FLOW AND MINIMAL  
FORCING. IT WILL BE VERY WARM AND HUMID WITH ENOUGH AFTN/EARLY  
EVENING INSTABILITY FOR ~20% POPS MOST AREAS (AND WITH A LITTLE  
MORE INSTABILITY WILL KEEP POPS TO NEAR 30% FOR INTERIOR NE NC)  
HIGHS 90-95 F INLAND AND MID- UPPER 80S/LOWER 90S NEAR THE  
COAST. LOWS GENERALLY 70-75 F. GFS/ECMWF DIVERGE WITH RESPECT TO  
DETAILS LATE TUE/WED, THE ECMWF SUGGESTING BUILDING HEAT AND  
LOWER POPS WHILE THE GFS SUPPORTS SLIGHTLY COOLER WX AND A HIGHER  
CHANCE FOR DAILY TSTMS. HAVE GENLY SPLIT THE DIFFERENCE AND  
JUST CARRIED 20 TO 30% POPS DURING CLIMO FAVORED TIMEFRAME (LATE  
AFTN AND EVENING). HIGHS CONTINUE TO BE 90-95 F INLAND AND  
UPPER 80S/AROUND 90 F ALONG THE COAST.  
 

 
   
AVIATION /02Z THURSDAY THROUGH MONDAY/
 
 
HIGH PRESSURE MOVES OFF THE COAST OVERNIGHT ALLOWING FOR MORE OF A  
SOUTHERLY FLOW ON THURSDAY. A COLD FRONT OVER THE MIDWEST WILL  
APPROACH THIS WEEKEND AND THEN STALL TO THE NORTH OF THE AREA.  
 
HIGH CONFIDENCE THAT VFR CONDITIONS WILL CONTINUE THROUGH THE 00Z  
TAF PERIOD. MAINLY CLEAR SKIES AND VARIABLE WINDS ARE ANTICIPATED  
OVERNIGHT. SCATTERED CUMULUS, AROUND 6000 FEET, DEVELOPS MAINLY  
AFTER 16Z. WINDS INCREASE OUT OF THE SOUTH BY TOMORROW AFTERNOON,  
OCCASIONALLY GUSTING TO NEAR 20 KNOTS.  
 
OUTLOOK: AFTERNOON/EVENING SHOWERS AND THUNDERSTORMS WILL BE  
POSSIBLE SATURDAY THROUGH MONDAY.  
 

 
   
MARINE
 
 
SFC HIGH PRESSURE NOW CENTERED ALONG THE SE VA COAST, WITH A  
LIGHT ONSHORE FLOW OF 5-10 KT OVER THE WATERS. SEAS AVG 2-3 FT FOR  
NC COASTAL WATERS AND 1-2 FT OR LESS ELSEWHERE. THE HIGH SLIDES  
JUST OFFSHORE TONIGHT, ALLOWING A BRIEF SURGE OF SSE FLOW UP THE BAY.  
NOT ENOUGH GRADIENT WITH THIS FOR ANY HEADLINES, BUT WAVES MAY BUILD  
TO 2-3 FT ACROSS THE NORTHERN BAY BY 06Z TONIGHT WITH ~15 KT WINDS.  
A SOMEWHAT MORE SIGNIFICANT SOUTHERLY FLOW WILL RESULT;T FROM A  
TIGHTER PRESSURE GRADIENT BY LATE THU AFTN AND ESPECIALLY THU  
NIGHT. HAVE RAISED SCA HEADLINES FOR THE BAY ZONES N OF NEW PT  
COMFORT FOR S WINDS AROUND 20 KT WITH SOME GUSTS TO AROUND 25 KT  
(STRONGEST WINDS MOST LIKELY FROM 00-06Z/FRI). FARTHER SOUTH IN  
THE BAY AND ACROSS THE RIVERS, THE GRADIENT IS A LITTLE WEAKER  
AND CONFIDENCE THEREFORE LOWER AND HAVE HELD OFF FOR NOW  
REGARDING HEADLINES AS THIS IS A LATE 2ND/3RD PERIOD EVENT. IN  
THESE AREAS, EXPECT SUSTAINED WINDS TO AVG 15 KT WITH GUSTS TO  
AROUND 20 KT. OTHER AREA WHERE A MARGINAL SCA EVENT WILL BE  
POSSIBLE IS THE COASTAL WATERS N OF PARRAMORE ISLAND WITH A SSW  
WIND TO AROUND 20 KT. WAVEWATCH/NWPS BLEND SUGGESTS MAINLY 4 FT  
SEAS IN THESE AREAS WITH THE POTENTIAL FOR SEAS APPROACHING 5 FT  
OUT 20 NM OFFSHORE. SEAS FARTHER SOUTH SHOULD STAY AT OR BELOW  
3-4 FT. SIMILAR CONDITIONS FRI AFTN/EVENING, THOUGH GUIDANCE  
SUPPORTS WINDS BEING SLIGHTLY WEAKER COMPARED TO THU NIGHT. A  
SLOW MOVING COLD FRONT APPROACHES FROM THE NW SAT BUT WEAKENS BY  
THE TIME IT REACHES THE LOCAL AREA ON SUNDAY. OUTSIDE OF ANY  
TSTMS, CONDITIONS WILL BE SUB-SCA WITH WINDS 10-15 KT OR LESS  
AND SEAS MAINLY 2-3 FT AND WAVES 1-2 FT.  
 

 
   
AKQ WATCHES/WARNINGS/ADVISORIES
 
 
MD...NONE.  
NC...NONE.  
VA...NONE.  
MARINE...SMALL CRAFT ADVISORY FROM 4 PM THURSDAY TO 4 AM EDT FRIDAY FOR  
ANZ630-631.  
 

 
 

 
SYNOPSIS...BMD/TMG  
NEAR TERM...BMD  
SHORT TERM...TMG  
LONG TERM...LKB  
AVIATION...AJB/LSA  
MARINE...LKB  
 
CLICK HERE TO GO TO PREVIOUS BULLETINS.

The Nexlab VA Page
The Nexlab NC Page
The Nexlab MD Page Main Text Page