Area Forecast Discussion
Issued by NWS Wakefield, VA

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
000
FXUS61 KAKQ 190734
AFDAKQ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WAKEFIELD VA
334 AM EDT FRI SEP 19 2014

.SYNOPSIS...
A TROF OF LOW PRESSURE DRIFTS WEST AND OVER THE MOUNTAINS TODAY.
HIGH PRESSURE BUILDS SOUTH AND ACROSS THE MID ATLANTIC REGION
THROUGH SUNDAY. A COLD FRONT CROSSES THE AREA SUNDAY NIGHT.

&&

.NEAR TERM /TODA/...
LATEST MSAS INDCTG WEAK SFC TROF FROM SRN DELAWARE SW ACROSS THE
VA & NC PIEDMONTS. LATEST RADAR TRENDS SHOW SCT SHWR ACTIVITY
ALONG THIS BNDRY ACROSS THE PIEDMONT.

MODELS AGREE IN SHIFTING THIS TROF WEST ACROSS THE MTS TODAY WITH
HIGH PRESSURE BUILDING INTO THE AREA FROM THE NORTH. TSCTNS SHOWING
ENUF MSTR AT DIFFERENT LEVELS FOR SCT-BKN CLOUDS ALONG WITH A NE
WIND FLOW. ANY TRIGGER FOR SCT SHWRS DRIFTS WEST THRU OUT THE DAY.
GIVEN THESE TRENDS...HELD ONTO THE 20 TO 30 POP ACROSS THE WRN HALF
OF FA ALTHOUGH CHCS DECREASE TO SLGHT CHC BY LATE AFTRN. OTW...VRBL
CLDNS WITH HIGHS IN THE M-U70S.

&&

.SHORT TERM /TONIGHT THROUGH SUNDAY NIGHT/...
VRBL CLDNS AGAIN TONIGHT BUT DRY AS SPRT FOR ANY SHWRS SHIFTS WEST.
SOME PTCHY FOG PSBL BUT WON`T INCLUDE IN GRIDS ATTM. LOWS IN THE
M50S-L60S.

NE FLOW CONTINUES ON SAT AS THE SFC HIGH MOVES FARTHER OFF THE NEW
ENGLAND COAST. TSCTNS SHOWING SOME DRYING AT MID LEVELS FOR MOST OF
THE DAY SO WILL KEEP A DRY FCST UNDER PT TO MSTLY SUNNY SKIES. H85
TMPS RISE TO BTWN 12-14C ALLOWING HIGHS TO TOP OUT IN THE U70S-M80S.

SFC LOW PRESSURE PROGGED TO DVLP OFF THE SERN COAST SAT THEN TRACK
NE ALONG THE GULF STREAM SAT NIGHT AND SUN MORNING BEFORE LIFTING NE
AND AWAY FROM THE AREA SUN AFTRN. STILL SOME MODEL DIFFERENCES WRT
HOW FAR WEST MSTR FROM THIS SYSTM GETS. FOR NOW...WILL CONTINUE TO
HIGHLIGHT MORE CLOUDS OVR ERN HALF OF FA WITH SLGHT CHC POPS ALONG
THE COAST SAT NIGHT AND SUN MORNING. LOWS SAT NIGHT U50S-M60S.

LOW PRESSURE TRACKS NE AND AWAY FROM THE RGN SUN WHILE THE NXT COLD
FRNT APPRCHS FROM THE WEST. DATA SUPPORTS SUBSIDENCE BEHIND THIS
SYSTM RESULTING IN SKIES BCMG PT TO MSTLY SUNNY BY THE AFTRN. H85
TMPS APPRCH SUMMER LEVELS (14-16C) ALLOWING HIGHS TO REACH THE
M-U80S. A 90 DEGREE READING IS PSBL OVR THE PIEDMONT GIVEN HOW DRY
THE GROUND IS ATTM.

ADJUSTED SUN NIGHTS FCST A BIT GIVEN THE LATEST TRENDS OF MSTR ALONG
THE COLD FRONT. EXPECT SCT CONVECTION TO DVLP ACROSS THE MTS LATE
SUN AFTRN THEN DRIFT SE ACROSS THE NRN HALF OF THE FA WHILE WEAKENING
SUN EVENING. ADDED SLGHT CHC THUNDER GIVEN HOW WARM / MARGINAL INSTAB
PROGGED OUT AHEAD OF BNDRY. KEPT SERN HALF OF FA DRY FOR NOW. LOWS
IN THE 60S.

&&

.LONG TERM /MONDAY THROUGH THURSDAY/...
A REINFORCING COLD FRONT WILL USHER IN BELOW NORMAL TEMPS THROUGH
THE EXTENDED AS COOL CANADIAN HIGH PRESSURE BUILDS OVER THE THE NE.

MEDIUM RANGE GUIDANCE IN FAIRLY GOOD AGREEMENT OVER THE ERN CONUS
WITH THE EVOLVING AMPLIFIED UPPER AIR PATTERN. AMPLIFIED PATTERN
WILL FEATURE A LONGWAVE TROUGH OVER THE ERN CONUS TO BEGIN THE
PERIOD. AN ASSOCIATED SECONDARY/REINFORCING COLD FRONT WILL SWEEP
THROUGH THE REGION MONDAY MORNING. MOISTURE WILL BE RATHER LIMITED
ALONG THE FRONT (PWATS ~1.5 INCHES)...BUT HEIGHT FALLS AND INCREASING
WINDS ALOFT (JET STREAK ROUNDING THE BASE OF THE UPPER TROUGH) WILL
PROVIDE FORCING FOR ASCENT OVER THE REGION. SHOULD BE ENOUGH FOR
SLIGHT CHANCE/ISOLATED POPS...WITH THE BEST COVERAGE OVER THE NRN
LOCAL AREA. THE BIGGER HEADLINE WITH THE FRONT WILL BE THE DRY AIR
AND COLD AIR ADVECTION POST FRONTAL AS HIGH PRESSURE BUILDS IN
FROM THE W-NW. MON WILL BE A TRANSITION DAY AS THE COOLEST/DRIEST
AIR LAGS BEHIND THE FRONT. REINFORCING SHORTWAVE CROSSES THE GREAT
LAKES-NE STATES TUES AS THE TROUGH AXIS PUSHES OFF THE ERN
SEABOARD. MEANWHILE...MID-LEVEL RIDGE WILL PROGRESS EWD OVER THE
CNTRL PLAINS AND INTO THE ERN CONUS TUES- WEDS. COOL CANADIAN HIGH
PRESSURE PROGGED TO BUILD OVER NEW ENGLAND WEDS. UPPER/SFC HIGH
PRESSURE REMAINS OVER THE REGION THURS. THE RESULT WILL BE
CONTINUED DRY CONDITIONS AND BELOW NORMAL TEMPS.

HIGHS WILL BE BELOW AVG THRU THE PERIOD...WITH TUES AND WEDS BEING
THE COLDEST DAYS AT NEARLY -1 STD DEV (LOW-MID 70S). WENT A LITTLE
ABOVE WPC GUIDANCE AS LOW LEVEL THICKNESSES YIELD SLIGHTLY WARMER
TEMPS UNDER MOSTLY SUNNY SKIES. LOWS GENERALLY IN THE LOW-MID 50S
INLAND TO LOW 60S NEAR THE COAST. FEW LOCALES IN THE PIEDMONT MAY
DROP INTO THE UPPER 40S AT NIGHT.

&&

.AVIATION /07Z FRIDAY THROUGH TUESDAY/...
AS OF 05Z...VFR SHOULD HOLD FOR THE 06Z TAF PERIOD. BKN-OVC CLOUDS
WITH BASES FROM 5 TO 8 KFT WERE OVER MOST OF THE AREA EXCEPT THE
FAR SE. ISOLD SHOWERS ARE EXPECTED TODAY ACRS WESTERN SECTIONS...PERHAPS
IMPACTING KRIC. LIGHT EASTERLY WINDS CONTINUE THROUGH THE PERIOD.

OUTLOOK...MAINLY VFR AND DRY WEATHER ARE EXPECTED TO CONTINUE INTO
EARLY NEXT WEEK. HIGH PRESSURE WILL PREVAIL THOUGH A WEAK COLD FRONT
CROSSES THE AREA ON SUNDAY NIGHT TO EARLY MONDAY.

&&

.MARINE...
NELY FLOW EXPECTED TODAY AS HIGH PRESSURE BUILDS OVER NEW ENGLAND.
GRADIENT DOES STRENGTHEN SOMEWHAT BY THIS AFTERNOON...WITH SPEEDS
REACHING 15 TO 20 KT OVER THE COASTAL WATERS. E-NE FLOW WILL HELP TO
BUILD SEAS THROUGH THE DAY...REACHING 4-5 FEET ON THE COASTAL WATERS
THIS EVENING AND OVERNIGHT. SCA HEADLINES GO INTO EFFECT FOR THE FAR
SOUTHERN WATERS AT 7 PM THIS EVENING...AND 1 AM SAT FOR THE
REMAINING COASTAL ZONES. IF WINDS END UP STRONGER THAN FORECAST...
6-7 FT SEAS WILL BE POSSIBLE OUT AROUND 20 NM. 4 FT WAVES WOULD ALSO
POSSIBLE AT THE MOUTH OF THE BAY.

HIGH PRESSURE WILL BEGIN TO SLOWLY PUSH OFF THE NE COAST SAT AS LOW
PRESSURE DEVELOPS ALONG A STALLED BOUNDARY OFF THE SE COAST. THE LOW
WILL LIFT ALONG THE BOUNDARY THRU THE WEEKEND...LOCATING OFF THE
MID-ATLANTIC COAST SOMETIME LATE THIS WEEKEND. SCA CONDITIONS FOR
WIND SPEEDS ARE NOT ANTICIPATED ATTM BASED ON THE GRADIENT WIND
FORECAST. HOWEVER...SEAS WILL LIKELY REMAIN ELEVATED (4-5 FT) THRU
SAT...BEFORE SUBSIDING ON SUNDAY AHEAD OF A COLD FRONT WITH WINDS
TURNING OFFSHORE.

SFC LOW LIFTS NE OFF THE COAST LATE IN THE WEEKEND WITH A COLD FRONT
FORECAST TO CROSS THE REGION SUN NIGHT-MON MORNING. SEAS MAY BRIEFLY
BUILD TO 5 FT AGAIN SUNDAY NIGHT. NW WINDS 10-15 KT ON MONDAY WILL
GRADUALLY BECOME N-NE ON TUESDAY. SEAS 2-4 FT. WAVES 1-2 FT.

&&

.HYDROLOGY...
LATEST DROUGHT INFO SHOWING AN AREA OF ABNORMALLY DRY CNDTNS ACROSS
PORTIONS OF VA. THIS INCLUDES AREAS N OF I 64 & RT 360 (INCLUDING
THE RIC METRO AREA) IN AKQ FA. OTHER THAN SCT CONVECTION WITH THE
FRNT SUN EVE...XTNDD MODELS DO NOT SHOW MUCH IN THE WAY OF RELIEF
FOR THE NEXT WEEK.

&&

.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...MODERATE RIP CURRENT RISK THROUGH THIS EVENING FOR MDZ025.
NC...MODERATE RIP CURRENT RISK THROUGH THIS EVENING FOR NCZ102.
VA...MODERATE RIP CURRENT RISK THROUGH THIS EVENING FOR VAZ098>100.
MARINE...SMALL CRAFT ADVISORY FROM 1 AM TO 7 PM EDT SATURDAY FOR ANZ650-
     652-654-656.
     SMALL CRAFT ADVISORY FROM 7 PM THIS EVENING TO 7 PM EDT
     SATURDAY FOR ANZ658.

&&

$$
SYNOPSIS...MPR
NEAR TERM...MPR
SHORT TERM...MPR
LONG TERM...SAM
AVIATION...JDM
MARINE...JDM
HYDROLOGY...MPR






USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.