Skip Navigation Linkswww.nws.noaa.gov 
NOAA logo - Click to go to the NOAA homepage National Weather Service Forecast Office   NWS logo - Click to go to the NWS homepage
Wakefield, VA banner image
 
 

Area Forecast Discussion
Latest Versions  [Current][-1][-2][-3][-4]



000
FXUS61 KAKQ 250005
AFDAKQ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WAKEFIELD VA
805 PM EDT THU APR 24 2014

.SYNOPSIS...
HIGH PRESSURE SLIDES OFFSHORE TONIGHT. LOW PRESSURE TRACKS FROM THE 
OHIO VALLEY ACROSS THE NORTHERN MID ATLANTIC FRIDAY...AND OFF THE 
COAST FRIDAY NIGHT. A COLD FRONT DROPS ACROSS THE REGION SATURDAY 
NIGHT...WITH HIGH PRESSURE BUILDING IN FROM THE GREAT LAKES SUNDAY.

&&

.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
CURRENT WV IMAGERY INDICATES AN UPPER TROUGH STEADILY TRACKING W-E 
ACROSS THE CENTRAL PLAINS...WITH ANOTHER TROUGH DOWNSTREAM OF THE 
LOCAL AREA OVER ATLANTIC CANADA. A NARROW RIDGE AXIS EXISTS OVER THE 
SOUTHEAST AND OHIO VALLEY...WITH SURFACE HIGH PRESSURE UNDERNEATH 
THIS FEATURE EXTENDING FROM THE EASTERN GREAT LAKES THROUGH THE MID 
ATLANTIC.

THE CENTRAL PLAINS TROUGH WILL LIFT NE THROUGH THE MID MISSISSIPPI 
VALLEY TOWARD THE GREAT LAKES OVERNIGHT. MEANWHILE...SURFACE HIGH 
PRESSURE WILL SLIDE OFFSHORE. THE SKY SHOULD BE MAINLY CLEAR THROUGH 
THE EVENING AND EARLY OVERNIGHT HOURS...BEFORE CLOUDS BEGIN TO 
INCREASE OVER WESTERN PORTIONS LATE. THE TEMPERATURE SHOULD DROP 
QUICKLY THROUGH THE EVENING HOURS...WITH COOL DRY HIGH PRESSURE OVER 
THE AREA...AND BECOME STEADY AFTER MIDNIGHT. LOWS SHOULD RANGE FROM 
THE UPPER 30S TO LOW 40S OVER INTERIOR PORTIONS E OF I-95...WITH 
LOW/MID 40S W DUE TO INCREASED MIXING (FROM LIGHT SE FLOW) AS THE 
HIGH SHIFTS OFFSHORE AND THE APPROACH OF LOW PRESSURE FROM THE W.

&&

.SHORT TERM /6 AM FRIDAY MORNING THROUGH SUNDAY/...
THE PARENT TROUGH LIFTS THROUGH THE GREAT LAKES FRIDAY...WITH 
SURFACE LOW PRESSURE TRACKING ACROSS THE NORTHERN MID-ATLANTIC. A 
PROMINENT (SURFACE AND MID-LEVEL) THETA-E RIDGE PRECEDES THE TROUGH 
AXIS. THIS SHOULD PRODUCE AN INCREASE IN BOUNDARY LAYER MOISTURE 
THROUGH THE MORNING. FORECAST SOUNDINGS SHOW A PERIOD OF RATHER DEEP 
MOISTURE ALONG WITH A PERIOD OF MODEST LIFT PASSING ACROSS THE LOCAL 
AREA LARGELY IN THE 18-00Z TIMEFRAME. GIVEN THIS THERE IS HIGH 
CONFIDENCE OF SHRA AND EMBEDDED TSRA PASSING ACROSS THE AREA. THE 
BEST DESTABILIZATION OCCURS OVER SE PORTIONS. THIS WILL BE IN THE 
PRESENCE OF MODEST DEEP LAYER SHEAR (~35KT 0-6KM)...AND ~30KT OF 
0-1KM BULK SHEAR. AT THIS TIME INSTABILITY APPEARS TOO MARGINAL TO 
SUPPORT ORGANIZED SEVERE WEATHER...BUT THERE IS ENOUGH SHEAR FOR A 
MINIMAL THREAT MAINLY ACROSS FAR SE VA/NE NE. HIGHS SHOULD GENERALLY 
BE IN THE LOW/MID 70S (LOCALLY COOLER ALONG THE COASTS).

THE MID-LEVEL COLD FRONT (COLD THETA-E BOUNDARY) MOVES OFF THE COAST 
LATE FRIDAY NIGHT...WITH DRIER AIR ARRIVING FROM THE W. THE SURFACE 
BOUNDARY IS MAINLY A WIND SHIFT...SO TEMPERATURES SATURDAY SHOULD 
GENERALLY BE A FEW DEGREES WARMER THAN FRIDAY. HIGHS ARE EXPECTED TO 
RANGE FROM THE MID 70S OVER EASTERN PORTIONS (LOCALLY COOLER ALONG 
THE IMMEDIATE COAST)...TO AROUND 80 ALONG A W OF I-95. THIS WILL BE 
AFTER MORNING LOWS RANGING FROM THE UPPER 40S NW...TO UPPER 50S SE.

SATURDAY SHOULD BEGIN MOSTLY SUNNY...BEFORE CLOUDS INCREASE 
(ESPECIALLY N) AHEAD OF A COLD FRONT APPROACHING FROM THE NW. AT 
THIS TIME POPS WILL BE HELD BELOW 15%...BUT A FEW SPRINKLES ARE 
POSSIBLE ACROSS THE FAR NORTHERN PORTIONS. THIS FOLLOWS MORE OF A 
12Z GFS/ECMWF SOLUTION RATHER THAN THE MORE MOIST 12Z NAM DUE TO THE 
EXPECTATION OF LIMITED BOUNDARY LAYER MOISTURE.

THE COLD FRONT DROPS THROUGH THE AREA SATURDAY NIGHT...WITH HIGH 
PRESSURE BUILDING IN FROM THE GREAT LAKES SUNDAY. LOWS SHOULD RANGE 
FROM THE MID 40S TO LOW 50S SUNDAY MORNING...FOLLOWED BY HIGHS 
SUNDAY AFTERNOON IN THE MID 60S NE TO LOW/MID 70S SW UNDER A MOSTLY 
SUNNY/CLEAR SKY.

&&

.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
A HIGHLY AMPLIFIED/BLOCKY PATTERN WILL RESULT IN AN UNSETTLED PRD 
NEXT WEEK. TODAYS MODELS CONTINUE TO SLOW THE ARRIVAL OF PCPN UNTIL
MON AFTRN WHEN THE STALLED FRONTAL BNDRY ACROSS THE CAROLINAS BEGINS 
TO MOVE BACK NORTH AS A WARM FRONT. KEPT SUNDAY NIGHT AND MON MORN 
DRY AS HIGH PRS TO THE NORTH IS SLOW TO RETREAT. LOWS M40S-L50S. 

MAIN UPR LEVEL LOW PROGGED TO SLOWLY EJECT EAST FROM NATIONS MID 
SECTION MONDAY TO THE OHIO/TNN VLLY WED. MODELS CONTINUE TO SHOW A 
SCNDARY LOW DVLPNG OVR THE MID ATLNTC REGION THURS WITH A TRAILING 
COLD FRONT PUSHING DEEPEST MOISTURE OFFSHORE LATE THURSDAY FOLLOWED 
BY LAGGING UPR LVL MOISTURE ACROSS THE AREA. 

NUMEROUS FORECAST CHALLENGES DURING THIS PRD. PRIME OF WHICH WILL BE 
THE LOCATION OF FRONTAL BOUNDARY NOW PROGGED TO HOVER SOMEWHERE ARND 
THE NC/VA BORDER TUES THRU THURS. THE UNCERTAINTY HERE WILL MAKE
A PROBLEMATIC FORECAST FOR TMPS...WIND DIRECTION AND PCPN TYPE
(I.E. CONVECTIVE VS STRATIFORMED). BETTER CONFIDENCE TODAY THAT
THE TUES THRU WED TIME FRAME WILL BE THE WETTEST...SO HAVE
INCREASED TO LIKELY POPS THEN. OTW...KEPT PCPN SHOWERS CWA WIDE
FOR NOW GIVEN THE LOW CONFIDENCE THIS FAR OUT. COULD VRY WELL END
UP BEING MORE OF A STRATIFORMED RAINFALL ACROSS THE PIEDMONT IF A
COOL E-NE WEDGE SETS UP AS WELL AS HAVING TO ADD THUNDER TO THE
SOUTHERN ZONES GIVEN A FRONTAL BOUNDARY LOCATION FARTHER NORTH.
ALL-IN-ALL...EXPECT A COOL AND WET PRD. HIGHS GNRLLY FROM THE
L-M60S NORTHERN HALF OF FA TO U60S-L70S SOUTHERN HALF. LOWS U40S-
M50S.

&&

.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
VFR CONDITIONS ARE EXPECTED THROUGH FRIDAY MORNING. SURFACE HIGH 
PRESSURE RIDGE WILL MOVE OFF THE COAST OVERNIGHT. A COLD FRONT 
APPROACHES FROM THE WEST FRIDAY MORNING AND CROSSES THE REGION LATE 
IN THE DAY. A BAND OF SHOWERS AND A FEW THUNDERSTORMS IS EXPECTED TO 
SET UP AHEAD OF THE FRONT. CONFIDENCE FOR SHOWERS AND MVFR 
CONDITIONS IS HIGH ENOUGH TO INCLUDE IN THE RIC AND SBY TAFS FRIDAY 
AFTN. TSTM ACTIVITY CAN BE ADDED IN LATER ISSUANCES WHEN TIMING OF 
ANY TSTMS BECOMES CLEAR. ANY IFR IS EXPECTED TO BE BRIEF. SOUTHEAST 
TO SOUTH WIND GUSTS TO OVER 20 KNOTS (AROUND 25 KNOTS AT ORF ECG AND 
PHF) ARE FORECAST FRIDAY AFTERNOON.  

OUTLOOK...PCPN MOVES ENDS SHORTLY AFTER THIS TAF PERIOD FRIDAY 
EVENING. DRY WEATHER AND MAINLY VFR IS INDICATED FRIDAY NIGHT 
THROUGH MONDAY. A SLOW MOVING LOW PRESSURE SYSTEM WILL SPREAD 
UNSETTLED WEATHER WITH PERIODS OF RAIN NEXT WEEK BEGINNING TUESDAY.

&&

.MARINE...
NO HEADLINES TONIGHT AND FRI MORNING AS HIGH PRS BUILDS OVER THE 
WATERS. EXPECT VARIABLE WINDS TO BECOME S-SE BY MORNING. PRS GRDNT
INCREASES AHEAD OF APPRCHG COLD FRONT FRI. DATA SHOWING HIGHER 
CONFIDENCE FOR AT LEAST MINIMAL SCA'S ACROSS THE CHES BAY FRI AFTRN.
FROPA FRI EVENING WITH A WIND SHIFT TO W-NW AFTR MIDNIGHT. ALTHOUGH 
DATA SHOWS LITTLE IN THE WAY OF CAA...EXPECT A FEW HR PRD OF MINIMAL 
SCA RIGHT BEHIND FROPA SO WILL KEEP SCA'S THROUGH THE NIGHT ACROSS 
THE CHES BAY. OTW...EXPECT WINDS & SEAS TO STAY BLO SCA LVLS ACROSS 
CSTL WTRS ATTM. 

WEST WINDS ERLY SAT AHEAD OF A WEAK TROF PROGGED TO CROSS THE WATERS 
SAT AFTRN. WIND SHIFT TO THE N BEHIND THIS FEATURE...BUT KEPT WINDS 
BLO SCA LEVELS AS MOST MODELS PROGG WEAK ADVECTION BEHIND THIS FTR.
GFS SOMEWHAT STRONGER WITH ITS SURGE AND HAS WINDS INTO MINIMAL SCA 
LEVELS SAT NITE. WILL TAKE A CLOSER LOOK AT THIS TOMORROW.

LARGE UPR LVL SYSTM XPCTD TO APPRCH THE AREA NEXT WEEK. ALTHOUGH 
WINDS NOT THAT STRNG...WNA SHOWING INCRG SWELL WITH SEAS 5-7 FT BY 
THE MIDDLE OF NEXT WEEK. HAVE SPLIT THE DIFFERENCE BUT INCRSD SEAS 
TO 4-6 FT FOR NOW.

&&

.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 1 PM FRIDAY TO 4 AM EDT SATURDAY FOR 
     ANZ630>632-634.

&&

$$
SYNOPSIS...AJZ
NEAR TERM...AJZ/JDM
SHORT TERM...AJZ
LONG TERM...MPR
AVIATION...LSA
MARINE...MPR







National Weather Service
Disclaimer Privacy Policy