Area Forecast Discussion
Issued by NWS Sterling, VA

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FXUS61 KLWX 271848
AFDLWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
248 PM EDT WED APR 27 2016

.SYNOPSIS...
A COLD FRONT WILL REMAIN STALLED NEAR THE VIRGINIA-NORTH CAROLINA
BORDER THROUGH FRIDAY. WAVES OF LOW PRESSURE WILL RIDE ALONG THE
BOUNDARY DURING THIS TIME. THE BOUNDARY MAY DROP A BIT FARTHER
SOUTH SATURDAY...BUT ANOTHER WAVE OF LOW PRESSURE WILL TRACK ALONG
THE FRONT FOR SUNDAY INTO MONDAY.
&&

.NEAR TERM /THROUGH TONIGHT/...
THE BNDRY REMAINS STALLED ACRS SRN VA TAFTN. TEMPS ONCE AGN IN
THE LWR 80S SOUTH OF THIS BNDRY...BUT ONLY IN THE LWR 50S ACRS
MUCH OF MD. A RDG OF SFC HIPRES EXTENDS DOWN THE COAST FM NEW
ENGLAND. IN ADDITION...A RDG AXIS EXISTS ALOFT ACRS THE GRTLKS TO
SERN CONUS. THEREFORE...THE NEAREST DIURNAL TSRA DVLPG ACRS ERN
KY/SRN WVA/WRN VA. THE QSTN WL BE WHETHER THESE STORMS CAN REACH
SRN CWFA. BASED ON SYNOP SETUP AND STBL AMS...AM BETTING AGAINST
IT. TO PROVIDE A BUFFER NEED TO INCL CHC POPS ACRS CENTRAL VA/SRN
MD...BUT FCST UNDERCUTS MOS SIGNIFICANTLY.

ISENT UPGLIDE IMPRV OVNGT...SO WL INCR POPS SLGTLY. AM NOT SOLD ON
ACCUM QPF...SO AM KEEPING POPS AT CHC.

UTILIZED A MDL BLEND FOR MIN-T...WHICH YIELDS UPR 40S ACRS NRN MD
TO MID 50S CENTRAL VA.

&&

.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
PTTN REMAINS UNCHGD THRU THE END OF THE WEEK...AS STALLED FRONT
POISED S OF CWFA. ANY S/WV RIDING ALONG THIS BNDRY CUD TRIGGER A
FEW SHRA. THERE WONT BE MANY SUBSTANTIVE CHGS TO THE FCST GIVEN
THESE SUBTLETIES...AND THE CHALLENGES W/ FORECASTING THEM THIS
FAR OUT.

ONE KEY FEATURE THAT IS DISCERNABLE ATTM IS THE CLOSED LOW ACRS
THE PLAINS OPENS UP AND TRAVERSES THE CONUS DURING THE PD. THE SFC
REFLECTION WL MIGRATE EWD AS WELL...ALONG THE BNDRY... WHICH WL
PROVIDE THE IMPETUS FOR SHRA. THEREFORE WL INCR POPS TO LKLYS THU
MIDDAY THRU MIDNGT.

BYD THAT IT IS UNCLR HOW MUCH MSTR THE SUBSEQUENT VORT WL HV...
EXACTLY WHERE IT WL TRACK...AND HOW STRONG IT WL BE. WL REVERT
BACK TO CHC POPS FOR FRI.

FEW TEMP CHGS DURING THE PD AS WELL. IT WL BE TOUGH FOR MUCH OF MD
TO CRACK 60 DEGF...SPCLY ON THU.

&&

.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
HIGH PRESSURE WILL REMAIN WEDGED ALONG THE EASTERN SLOPES OF THE
APPALACHIAN MOUNTAINS SATURDAY THROUGH SUNDAY. SOME OVERRUNNING
WARMTH AND MOISTURE SATURDAY NIGHT AND AN APPROACHING UPPER LEVEL
DISTURBANCE WILL RIDE ALONG THE OHIO VALLEY INTO OUR REGION AND
BRING A THREAT FOR PERIODS OF RAIN.

PERIODS OF RAIN WILL BECOME MORE PRONOUNCED AND PROLONGED SUNDAY
INTO SUNDAY NIGHT AS THE MAIN UPPER LEVEL TROUGH PIVOTS INTO THE
AREA AND A SURFACE LOW PRESSURE SYSTEM DEVELOPS OVER SOUTHWEST
VIRGINIA.

ADDITIONAL UPPER LEVEL ENERGY WILL ROTATE WITHIN THE MAIN TROUGH OF
LOW PRESSURE MONDAY INTO MONDAY NIGHT...LEAVING THE CHANCE FOR
ADDITIONAL RAIN SHOWERS ACROSS THE REGION.

THE SURFACE LOW AND UPPER ENERGY SHOULD EXIT THE EAST COAST TUESDAY
TO ALLOW FOR A RIDGE OF HIGH PRESSURE TO BUILD INTO THE REGION
TUESDAY NIGHT AND WEDNESDAY. DRIER CONDITIONS ON THE WAY.
&&

.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
UNSTTLD PTTN THRU THE TAF PD...AND THRU THE END OF THE WK FOR
THAT MATTER. STALLED FRNTL BNDRY S OF THE TERMINALS. ONSHORE FLOW
BRINGING MARINE STRATUS/STCU. WL STICK MAINLY W/ MVFR FLGT CONDS.
CUD BE A FEW SHRA INVOF CHO THIS EVNG...BUT LOW CONFIDENCE. BETTER
CHC AT SEEING SHRA THU PM. PDS OF IFR PSBL TNGT...AND SPCLY THU
AFTN-NGT. HV NOT PLACED AOB IFR IN ANY TAF ATTM.

SHOULD IMPROVE TO VFR ON FRI. VFR CONDITIONS EXPECTED SATURDAY AS
WELL. WINDS NORTHEAST LESS THAN 5 KNOTS. VFR CONDITIONS BECOMING
MVFR OR IFR SATURDAY NIGHT WITH APPROACHING RAIN SHOWERS FROM THE
WEST. WINDS BECOMING SOUTHEAST AROUND 5 KNOTS.
&&

.MARINE...
ONSHORE FLOW WL REMAIN IN PLACE THRU THE END OF THE WEEK INTO THE
WKND. WIND SPDS AOB 10-15 KT THRU THE PD.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...NONE.

&&

$$
SYNOPSIS...HTS
NEAR TERM...HTS
SHORT TERM...HTS
LONG TERM...KLW
AVIATION...HTS/KLW
MARINE...HTS



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