Area Forecast Discussion
Issued by NWS Sterling, VA

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000
FXUS61 KLWX 150715
AFDLWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
315 AM EDT MON SEP 15 2014

.SYNOPSIS...
HIGH PRESSURE OVER THE AREA WILL DRIFT EAST TODAY. A COLD FRONT
PASSES THROUGH THE AREA LATE TONIGHT. HIGH PRESSURE RETURNS
TUESDAY...THEN PERSISTS THROUGH THE END OF THE WEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
HIPRES HAS SETTLED OVERHEAD...PROVIDING CALM AND COOL CONDS. ITS NOT
CLEAR THO...A RESULT OF TRAPPED MSTR UNDER LRG SUBSIDENCE INVSN PER
00Z LWX RAOB. THINK WE/LL HV THESE PATCHES OF CLDS THRU SUNRISE...
WHEN PERHAPS THEY CAN MIX OUT.

SFC HIPRES WL GRDLY MV OFFSHORE TDA. MEAN LYR RH WL BE HIGH ENUF TO
SUPPORT AT LEAST SCT CLDS...AND MID-UPR LVL MSTR WL BE INCRSG THRU
THE AFTN DUE TO WAA. WHILE CONCEPTUALLY...MAV MAXT NUMBERS MAY SEEM
TO BE BETTER...FCSTS HV BEEN EXHIBITING A WARM BIAS PAST CPL DAYS.
HV UTILIZED BIAS CORRECTED GRIDS TO COMPENSATE...WHICH WL LWR MAXT
FCST BY A CPL DEGF FOR MOST OF THE AREA.

THTE RDG WL APPROACH FM THE S TNGT AHD OF A CDFNT ARRIVING FM THE W.
BY FAR...MOST OF THE NRN STREAM PVA ENERGY WL REMAIN ACRS NY/PA.
THUS THE TWO AREAS NEVER REALLY JOIN FORCES...RESULTING IN A
DISORGANIZED UPA PTTN. QPF...IF ANY...SHUD BE LGT. GDNC POPS LWR
OVERALL. THINK THATS A GOOD IDEA. WHATEVER SCT SHRA WE WL HV MOST
LKLY WL OCCUR OVNGT.

DEWPTS WL BE RISING TAFTN-TNGT INTO THE 50S TO PERHAPS 60F. USED
THAT AS A GUIDE FOR MIN-T FCST. MET MOS CAME CLOSEST...BLENDED W/
GOING FCST.

&&

.SHORT TERM /TUESDAY THROUGH TUESDAY NIGHT/...
CDFNT WL CLEAR AREA BY DAYBRK TUE. ITS LOOKING REAL DOUBTFUL TO HV
ANY LINGERING SHRA INTO ELY TUE...AS BINOVC SHUD BE DVLPG BY
SUNRISE. CAA MOST NOTEABLE WX FEATURE...PROVIDING A WELL MIXED
ATMOS. BUFKIT SUGGESTS 20 KT AT TOP OF LYR. HV GUSTY WINDS IN GRIDS
DOWN PTMC AND ACRS MD.

AM XPCTG CLDS TO BREAK APART DURING THE MRNG. MOSUN MOST OF THE DAY.
COMPRESSIONAL WARMING MAY OFFSET SOME OF THE CAA. INCORPORATED THE
TWO CONCEPTS FOR MAXT. FCST CHGS /SLGTLY COOLER/ W OF BLURDG AND
ACRS NRN MD.

AS HIPRES BLDS TUE NGT...SHUD HV CLR/CALM NGT...WHICH WL EQUATE TO
ANTHR COOL NGT. UTILIZED THE COOLER MOS OFFERINGS.

&&

.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
HIGH PRESSURE WILL CONTINUE TO RESIDE ACROSS THE MID ATLANTIC
WEDNESDAY. WINDS WILL BE VARIABLE IF NOT CALM DURING THE DAY WITH
FCST MAX TEMPS IN THE UPPER 60S IN THE MTNS TO LOW TO MID 70S
ELSEWHERE.

A WEAK DISTURBANCE WILL DRIFT SOUTHWARD FROM THE GREAT LAKES WHILE A
STRONGER AREA OF HIGH PRESSURE MOVES ACROSS ONTARIO THURSDAY. ECMWF
IS MORE PRONOUNCED THAN THE GFS WITH THE FEATURE BUT BOTH HAVE
LITTLE MOISTURE WITHIN THE COLUMN. DRY CONDITIONS ARE EXPECTED AND
LIGHT NRLY FLOW WILL CONTINUE ACROSS THE MID-ATLANTIC. FCST MAX
TEMPS WILL CONTINUE TO BE SLIGHTLY BELOW NORMAL...IN THE UPPER 60S
IN THE MTNS AND LOT O MID 70S ELSEWHERE THURSDAY.

HIGH PRESSURE WILL MOVE EASTWARD BY THE END OF THE WEEK. A WEDGE
SHOULD SETUP BY FRIDAY AFTERNOON AND WINDS WILL BECOME N-NE. THIS
SETUP WILL CONTINUE INTO SATURDAY AS HIGH PRESSURE MOVES OFF THE NEW
ENGLAND COAST. A SHORTWAVE TROUGH WILL APPROACH THE POTOMAC
HIGHLANDS THIS WEEKEND. SHOWERS ARE POSSIBLE SUNDAY.

&&

.AVIATION /07Z MONDAY THROUGH FRIDAY/...
VFR CONDS ACRS THE TERMINALS ATTM. HWVR...FOG HAS DVLPD INVOF
CJR/HWY AND W99. GDNC EXIBITING ITS TYPICAL BIAS OF OVERDOING
CVRG. DO THINK THAT THERE IS POTL...SPCLY FOR CHO AND PERHAPS MRB.
HV LIMITED RESRICTIONS TO BRIEF IFR AT CHO AND MRVF AT MRB NEAR
SUNRISE.

VFR CONDS WL PREVAIL FOR THE REST OF THE DAY INTO THE EVNG. A WK
CDFNT WL CROSS THE TERMINALS OVNGT. ATTM...AM THINKING THAT SHRA
CVRG SHUD BE SCT AND LGT IN NATURE. NOT WORTH INTRO RESTRICTIONS
INTO FCST ATTM.

HIGH PRESSURE WILL RESIDE ACROSS THE REGION. NO FLIGHT RESTRICTIONS
EXPECTED FOR THE END OF THE WEEK AT THIS TIME.

&&

.MARINE...
WNDS AOB 5 KT UNDER HIPRES. IT WL REMAIN THAT WAY THRU THE DAY ON
MON. WL HV A SLY FLOW DVLP AHD OF AN UPR LVL DISTURBANCE AND
CDFNT MON NGT. HV CAPPED WNDS AT 10 KT FOR THE EVNG AND 15 KT FOR
THE OVNGT HRS.

CFP COMING NEAR SUNRISE TUE. A NWLY SURGE BHD THE FNT SHUD SUPPORT
DECENT MIXING. HV ISSUED SCA ALL WATERS FOR 20 KT GUSTS DURING THE
DAY.

HIGH PRESSURE WILL RESIDE ACROSS THE WATERS MID TO LATE WEEK.

&&

.TIDES/COASTAL FLOODING...
WATER LVLS AVERAGING BETWEEN 1/2 TO 3/4 FT ABV ASTRO NORMS...
CLOSER TO 3/4 FT ON THE BAY. THESE POSITIVE DEPARTURES WILL REMAIN
THROUGH AT LEAST THE MONDAY NIGHT/TUESDAY MORNING TIDE CYCLE.

CBOFS INDICATES ANNAPOLIS WILL TOUCH MINOR FLOOD AGAIN THIS
MORNING...AND SOLOMONS/PINEY POINT WILL THREATEN AS WELL.
ESTOFS...ON THE OTHER HAND...IS SUGGESTING THAT THE MRNG TIDE WILL
BE OK. ETSS IN BETWEEN...SIDING CLOSER TO CBOFS. WHILE CBOFS HAS A
HIGH BIAS AT ONSET...IT TENDS TO BE PRETTY GOOD AFTER THAT. HAVE
MORE CREEDENCE IN A CBOFS/ETSS BLEND.

AM STILL UNSURE HOW THIS WILL TRANSLATE TO OBSVD WATER LEVELS.
SUSPECT WE WILL REACH CAUTION STAGE AND APPROACH MINOR STAGE WITH
INCOMING TIDE. THE MARGIN BETWEEN THE TWO WILL BE A MATTER OF A
COUPLE OF INCHES.

REGARDLESS OF WHAT HAPPENS THIS MRNG...THE PM TIDE CYCLE IS
LOOKING HIGHER. ALL GUIDANCE IS IN DECENT AGREEMENT ON THAT.
THEREFORE...ADVYS APPEAR PROBABLE FOR THIS AFTN-TNGT.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 9 AM TO 5 PM EDT TUESDAY FOR
     ANZ530>543.

&&

$$
SYNOPSIS...HTS
NEAR TERM...HTS
SHORT TERM...HTS
LONG TERM...HAS
AVIATION...HTS/HAS
MARINE...HTS/HAS
TIDES/COASTAL FLOODING...HTS






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