168
FXUS61 KAKQ 041959
AFDAKQ
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WAKEFIELD VA
359 PM EDT SAT JUL 4 2009
SYNOPSIS
WEAK HIGH PRESSURE SLOWLY PUSHES OFFSHORE TONIGHT...MEANWHILE AN
AREA OF LOW PRESSURE APPROACHES BY EARLY SUNDAY...PUSHING A COLD
FRONT TO THE COAST LATE SUNDAY NIGHT THROUGH EARLY MONDAY MORNING.
HIGH PRESSURE BUILDS BACK IN FOR THE FIRST PART OF THE WORK WEEK.
NEAR TERM /UNTIL 6 AM SUNDAY MORNING/
SFC HIGH PRES OVR THE SE STATES PROVIDING A VERY NICE, DRY &
SEASONABLE 4TH OF JULY. HIGH TEMPS WILL TOP OUT AT RIGHT AROUND
CLIMO NORMAL (MID TO UPR 80S) LATE THIS AFTN. APPEARS PRECIP CHANCES
WILL HOLD OFF UNTIL WE GET CLOSER TO MIDNIGHT AS AN AREA OF LOW PRES
FROM THE MS RVR VALLEY APPROACHES THE REGION. INCREASING CLDS AND
PRECIP CHANCES WILL PREVAIL OVERNIGHT...AND WHILE INSTABILITY
LOOKS ANEMIC AT THIS POINT...LEFT IN CHC FOR AN ISOLATED TSTMS.
LOWS TONIGHT MAINLY IN THE MID-UPR 60S.
SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY/
FOR SUN...THE LOW CROSSES THE REGION AND EXITS OFF THE COAST SUN
NIGHT. MDL CONTINUITY IS GENERALLY VERY GOOD FOR THIS SYSTEM SO LEFT
IN LIKELY POPS FOR TOMORROW. INSTABILITY LOOKS MARGINAL...EXCEPT
FOR ACROSS FAR SRN COUNTIES WHERE SPC HAS OUTLOOKED THIS AREA IN A
SLIGHT RISK. TEMPS ON SUN A BIT TRICKY CONSIDERING THE
PRECIP...RANGING FROM MID 70S FOR RIC AND VCNTY TO LOW 80S FOR VA
BEACH AND SWARD.
LOW MVS OFF THE COAST MON MORNING...LEAVING ONLY A LINGERING SHWRS
ACROSS COASTAL AREAS UNTIL NOON. HIGH PRES QUICKLY BUILDS BACK OVR
THE REGION IN EARNEST ON MON AND TEMPS RETURN TO CLIMO NORM VALUES.
CONTINUED WARM AND DRY FOR TUE.
LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/
GFS/ECMWF COMING INTO BETTER AGREEMENT FOR THE EARLY PORTION OF THE
EXTENDED (WED/THU)...WITH HIGH PRESSURE CENTERED ACROSS THE NORTHERN
MID ATLC REGION...AND DEEPER MSTR WELL OFF TO OUR SOUTH. EXPECT
SLIGHTLY BELOW AVG TEMPS BOTH DAYS (HIGHS LWR 80S N AND E TO MID/UPR
80S CNTRL AND SOUTH) WITH MAINLY DRY CONDITIONS. FOR FRI/SAT FAVOR A
BLEND BETWN MUCH FASTER 12Z GFS AND SLOWER 12Z ECMWF. THIS YIELDS A
WARMING TREND AS THE SFC HIGH BECOMES CENTERED OFF THE COAST AND LOW
LVL FLOW TURNS BACK TO THE SSW. WILL KEEP FRI DRY...THEN HAVE 20-30%
POPS BY SAT AFTN AS NEXT FRONT DROPS INTO THE REGION. HIGHS BOTH
DAYS INTO THE UPR 80S TO LWR 90S AND LOWS IN THE MID/UPR 60S TO LWR
70S.
AVIATION /20Z SATURDAY THROUGH THURSDAY/
LATEST SATELLITE IMAGERY SHOWS AFTRN CU SLOWLY MOVING E ACROSS
THE FA. VFR CONDS WILL CONTINUE THIS AFTRN THROUGH SUN MORNING.
MID LVL CLDS MOVE IN EARLY SUN MORNING AS A LOW APPROACHES FROM
THE WEST. DID NOT ADD PRECIP TO TAFS JUST YET AS BULK OF PRECIP
LOOKS TO STAY OUT OF THE FA UNTIL SUN AFTRN.
AREAS OF SHWRS AND PSBLE TS WILL AFFECT THE TAF SITES SUN AFTRN
AND EVENING. SOME MVFR/IFR CONDS POSSIBLE AS RAIN HELPS TO
SATURATE THE LOWER LVLS CAUSING CIGS TO LOWER. OTHERWISE...EXPECT
VFR CONDS THROUGH SUN EVENING. A DRY PERIOD WITH MAINLY VFR CONDS
RETURN FOR MON THROUGH WED AS HIGH PRESSURE MOVES INTO THE OHIO
VALLEY.
MARINE
CHANGEABLE CONDITIONS OVER THE NEXT FEW DAYS...AS LOW PRESSURE
DEVELOPS ALONG A COLD FRONT AS IT STALLS OVER SOUTHERN VA. EXACT
LOCATION OF THE SFC LOW AND BNDRY WILL MAKE FOR A CHALLENGING WIND
FCST SUNDAY/SUNDAY NIGHT. GOING WITH A BLEND OF THE GFS/NAM FOR MSLP
FIELDS...LEADING TO LIGHT NORTHERLY FLOW LATER TONIGHT (FOR NRN
WATERS)...TURNING EAST AND EVENTUALLY SOUTHERLY DURING THE DAY
SUNDAY. DOES NOT APPEAR TO BE A STRONG ENOUGH GRADIENT TO WARRANT
SMALL CRAFT ADVSY BUT DO ANTICIPATE WIND SPEEDS OVER SRN CSTL WATERS
TO INCREASE TO 15-20 KTS. FRONT THEN PUSHES THROUGH LATER SUNDAY
NIGHT AND SFC LOW TRACKS OFF THE COAST...WITH WINDS TURNING
NORTHERLY TWDS DAYBREAK MONDAY. TOO MUCH UNCERTAINTY TO RAISE FLAGS
FOR A LATE 3RD PERIOD EVENT...BUT THERE WILL PROBABLY BE A PERIOD OF
WINDS TO AROUND 20 KT. FRONT ESSENTIALLY REMAINS TO OUR SOUTH
THROUGH THE REST OF THE WEEK...BUT ANOTHER REINFORCING SURGE OF
NORTH WINDS LOOKS TO COME THROUGH TUE NIGHT/ERLY WED.
AKQ WATCHES/WARNINGS/ADVISORIES
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...NONE.
SYNOPSIS...SMF
NEAR TERM...SMF
SHORT TERM...SMF
LONG TERM...LKB
AVIATION...AM
MARINE...LKB
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