Area Forecast Discussion
Issued by NWS Wakefield, VA

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000
FXUS61 KAKQ 250258
AFDAKQ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WAKEFIELD VA
958 PM EST SAT JAN 24 2015

.SYNOPSIS...
LOW PRESSURE WILL CONTINUE TRACKING WELL OFF TO THE NORTHEAST OF
THE REGION THIS EVENING AS HIGH PRESSURE BEGINS TO BUILD IN FROM
THE SOUTHWEST. THIS HIGH WILL SHIFT OFF THE SOUTHEAST COAST SUNDAY
AFTERNOON...AS ANOTHER LOW PRESSURE SYSTEM APPROACHES FROM THE
NORTHWEST. THIS LOW WILL CROSS THE AREA SUNDAY NIGHT INTO MONDAY..AND
WILL RAPIDLY INTENSIFY OFF THE MID ATLANTIC AND NEW ENGLAND COASTS
LATE MONDAY THROUGH TUESDAY.

&&

.NEAR TERM /THROUGH SUNDAY/...
THE EVENING ANALYSIS DEPICTS ~972 MB SFC LOW PRESSURE NOW WELL OFF
TO OUR NE AND CENTERED NEAR THE SRN TIP OF NOVA SCOTIA. WEAK HIGH
PRESSURE IS CENTERED OVER THE NRN GULF OF MEXICO. THE COMBINATION
OF LOW PRESSURE TO THE NE AND HIGH PRESSURE TO THE SW IS PRODUCING
A REGION OF WLY FLOW ACROSS THE MID-ATLANTIC. THE MID- LEVEL
SHORTWAVE TROUGH AXIS HAS NOW PULLED OFFSHORE LEAVING A CLEAR SKY
IN ITS WAKE. OVERALL CLEAR CONDITIONS ARE EXPECTED TO PREVAIL
TONIGHT...WITH THE EXCEPTION OF FAR NRN/NE PORTIONS WHERE SCT MID-
CLOUDS COULD PASS THROUGH OVERNIGHT. NOT A LOT OF COLD AIR TO OUR
W/NW...SO LOWS OVERNIGHT WILL GENLY BE FROM THE UPPER 20S TO THE
LOWER 30S.

ON SUN...CLIPPER SYSTEM CURRENTLY TAKING SHAPE ACRS THE UPPER
MIDWEST PROGGED TO DIVE ESE INTO THE MID MS VALLEY BY 12Z INTO THE
LWR OH VALLEY BY 00Z/MON. THIS AS SFC HIGH SHIFTS OFF THE SE COAST.
SHOULD BE A MILD DAY WITH PARTLY TO MOSTLY SUNNY SKIES...HIGHS
INTO THE MID 50S SOUTH TO THE UPPER 40S NORTH.

&&

.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/...
ACTIVE PATTERN IN THE SHORT TERM...GENERAL PATTERN IS AGREED UPON
BY THE LATEST 12Z SUITE OF MODELS...BUT WITH DIFFERENCES IN
PLACEMENT OF THE EVENTUAL TRACK OF THE SFC LOW OFF THE COAST LATE
MON-TUE LEADING TO SUBSTANTIAL DIFFERENCES IN SENSIBLE WX...MAINLY
POTENTIAL SNOW AMOUNTS FOR THE REGION LATE MON-TUE. 12Z ECMWF IS
BY FAR THE MOST AGGRESSIVE AT DEVELOPING A CUTOFF UPPER LOW IN THE
VICINITY OF THE DELMARVA MON NIGHT/TUE...WHILE THE GFS AND NAM ARE
WEAKER WITH THIS FEATURE.

MAIN THEME FOR SUN NIGHT INTO MIDDAY MON IS A SLOWER ARRIVAL OF
COLD AIR...THUS MOST OF THE CWA WILL SEE RAIN THROUGH MOST OF THE
DAY MON...RATHER THAN SNOW. WILL CARRY HIGH CHC TO LIKELY POPS
(HIGHER NORTH) AFTER MIDNIGHT THROUGH MON AM. LOWS IN THE UPPER
30S S TO THE LOWER 30S N. CONFIDENCE IN THE MON NIGHT TO TUE PERIOD
IS BELOW AVG GIVEN THE MAJOR MODEL DISCREPANCIES...THE ECMWF
FORECASTING A BLIZZARD FOR THE NRN MID ATLC REGION AND NE
STATES...WHILE THE GFS/NAM WOULD SUGGEST OUR NE ZONES GET
"BRUSHED" WITH LIGHT SNOW ACCUMULATIONS. HAVE GENLY SPLIT THE
DIFFERENCE FOR NOW AND GONE CLOSE TO WPC FORECASTS. MOST OF THE
CWA HAS A GOOD CHC FOR SEEING AT LEAST LIGHT SNOW ACCUMULATIONS
MON NIGHT/TUE MORNING...WITH THE MOST UNCERTAINTY OVER THE ERN 1/3
OF THE CWA WHERE A SIGNIFICANT WINTER STORM IS POSSIBLE. WILL
CARRY LIKELY POPS E TO HIGH CHC ELSEWHERE MON AFTN THROUGH MON
NIGHT INTO TUE MORNING. HIGHS MON WERE RAISED INTO THE 45-50 F
RANGE ACRS THE SOUTH...WITH UPPER 30S OVER THE FAR NORTH. TEMPS
WILL LIKELY FALL LATER IN THE AFTN...WITH PTYPE BECOMING MAINLY
SNOW FROM N TO S LATE MON AFTN INTO MON EVENING. LOWS MON NIGHT IN
THE MID/UPPER 20S TO LOWER 30S WITH HIGHS TUE IN THE 30S.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
LOW PRESSURE DEEPENS AND LIFTS AWAY FROM THE MID-ATLANTIC COAST TUES
NIGHT AS THE DEEP/ANOMALOUS NRN STREAM TROUGH REMAINS OVER THE LOCAL
AREA. THE TROUGH AXIS PROGGED TO PUSH OFFSHORE WEDS RESULTING IN
NWLY FLOW ALOFT. DISTURBANCES IN THE NWLY FLOW ALOFT WILL TRAVERSE
THE LOCAL AREA WEDS...BUT HIGH PRESSURE BUILDING IN AT THE SFC AND
DRYING CONDITIONS ALOFT WILL KEEP THE FORECAST DRY. CAA WILL RESULT
IN H85 TEMPS FALLING TO AROUND -6 TO -10C DURING THE DAY...YIELDING
TEMPS IN THE MID-UPPER 30S. COLDER TEMPS OVER THE ERN SHORE...WITH
HIGHS IN THE LOW 30S. UPPER/SFC HIGH PRESSURE BUILDS OVER THE REGION
WEDS NIGHT AS THE NEXT SHORTWAVE AND ASSOCIATED SFC LOW APPROACH
FROM THE WEST ON THURS. SFC LOW AND TRAILING COLD FRONT CROSS THE
REGION THURS NIGHT-FRI MORNING. WHILE THE STRONGEST HEIGHT FALLS ARE
EXPECTED TO CROSS THE REGION...BEST MOISTURE PROGGED TO BE ACROSS
THE NE. WILL CARRY CHANCE POPS GENERALLY NORTH AND EAST OF RICHMOND
THURS NIGHT AND SLIGHT CHANCE SOUTH AND WEST. THERMAL PROFILES...LOW
TEMPS AND AIR MASS SUPPORT PREDOMINATELY RAIN ATTM...BUT RAIN/SNOW
MIX IS POSSIBLE OVER THE NE ZONES. DRYING FRI AS HIGH PRESSURE
BUILDS INTO THE REGION. THEREAFTER...MODELS COMPETING ON WHICH
STREAM WINS THRU THE WEEKEND. GFS FAVORS A SRN STREAM SYSTEM WITH
THE ECMWF FAVORING A NRN STREAM SYSTEM.

TEMPS GENERALLY NEAR NORMAL THURS-FRI...DROPPING INTO THE UPPER
30S-LOW 40S SAT.

&&

.AVIATION /03Z SUNDAY THROUGH THURSDAY/...
AS OF 0045Z...LOW CLOUDS HAVE JUST ABOUT EXITED THE COAST WITH JUST
A FEW REMNANTS OF CLOUDS AROUND 15 HUNDRED FT IN THE HAMPTON ROADS
AREA FIRST COUPLE OF HOURS. THE SKY WILL BE CLEAR EXCEPT FOR SOME
MID OR HIGH CLOUDS SUNDAY AFTERNOON.

OUTLOOK: ANOTHER WEATHER SYSTEM WILL IMPACT THE AREA MONDAY INTO
TUESDAY. THIS COULD AGAIN CAUSE SOME MVFR TO IFR CEILINGS ALONG
WITH A CHANCE FOR SOME WINTRY PRECIPITATION...MOST LIKELY RAIN
SHOWERS CHANGING TO SNOW SHOWERS MONDAY INTO TUESDAY. SOME
ACCUMULATING SNOW WILL BE PSBL ESPECIALLY AT SBY BY TUESDAY MORNING.
HIGH PRESSURE BUILDS OVER THE REGION FROM THE WEST FOR MID TO LATE
WEEK...WITH VFR CONDITIONS EXPECTED FOR MUCH OF THE PERIOD.

&&

.MARINE...
LATEST WX ANALYSIS DEPICTS INTENSIFYING LOW PRESSURE OFF LONG
ISLAND THIS AFTERNOON. FLOW OVER THE WATER GENERALLY NWLY 15-25
KT...WITH SOME GUSTS UP TO 30 KT OVER THE COASTAL WATERS. WAVES
GENERALLY 2-4 FT AND SEAS 5-7 FT. SCA HEADLINES REMAIN IN EFFECT
FOR THE BAY/SOUND/LOWER JAMES/COASTAL WATERS. NWLY WINDS OVER THE
ERN VA RIVERS HAVE INCREASED SLIGHTLY THIS AFTERNOON TO AROUND 15
KT...BUT SCA CONDITIONS NOT ANTICIPATED. LOW-LEVEL CAA WANES THIS
EVENING OVER THE BAY AS THE PRESSURE GRADIENT RELAXES...ALLOWING
HEADLINES OVER THE BAY/SOUND/LOWER JAMES TO DROP OFF. STILL
ANTICIPATE GUSTS OF 20 KT IN THE MOUTH OF THE BAY AND GUSTS TO 25
KT IN THE COASTAL WATERS...SO WILL MAINTAIN SCA HEADLINES. SEAS
SUBSIDE THRU THE NIGHT...DROPPING BELOW 5 FT EARLY SUN MORNING.
HIGH PRESSURE BUILDS OVER THE SE STATES SUN...EXTENDING NWD OVER
THE WATERS. FLOW BECOMES SLY DURING THE AFTERNOON AOB 10KT. THE
NEXT IN A SERIES OF CLIPPER SYSTEMS PROGGED TO CROSS THE WATERS
MON. THE LOW IS THEN EXPECTED TO STRENGTHEN RAPIDLY AS IT LIFTS
NWD ALONG THE COAST. MODELS HANDLING THE STRENGTH OF THE LOW
DIFFERENTLY...WITH THE GFS AND ECMWF BEING DEEPER WITH THE SFC LOW
AND STRONGER WITH THE WINDS. CERTAINTY IS FOR STRONG SCA
CONDITIONS...WITH INCREASING CERTAINTY FOR LOW END GALE
CONDITIONS...ESPECIALLY OVER THE COASTAL WATERS. ANOTHER WEAKER
SYSTEM CROSSES THE WATERS TUES...REINFORCING THE COLD AIR OVER THE
REGION. THE RESULT WILL BE AN EXTENDED PERIOD OF SCA CONDITIONS
OVER THE WATERS. BEST CHANCE FOR GALES WILL BE MON NIGHT WITH SCA
CONDITIONS PERSISTING THRU TUES NIGHT. SEAS MAY REMAIN ELEVATED
AOA 5 FT THRU THE DAY WEDS. HIGH PRESSURE RETURNS LATE WEDS INTO
WEDS NIGHT...IN ADVANCE OF THE NEXT SYSTEM SET TO CROSS THE WATERS
THURS NIGHT. SCA CONDITIONS APPEAR POSSIBLE YET AGAIN.

&&

.TIDES/COASTAL FLOODING...
LOW PRESSURE IS FORECAST TO INTENSIFY RAPIDLY OFF THE MID-ATLANTIC
COAST MONDAY NIGHT. THE RESULT WILL BE A PERIOD OF STRONG NLY
WINDS OVER THE WATERS. TIDAL ANOMALIES ARE EXPECTED TO REACH 1 TO
1.5 FT...POSSIBLY HIGHER...DURING MONDAY NIGHT AND TUESDAY
MORNINGS HIGH TIDE CYCLES. SEVERAL SITES IN THE LOWER BAY WILL
REACH HIGHEST ASTRO TIDE WITH WATER LEVELS APPROACHING MINOR
FLOODING THRESHOLDS AT SEWELLS POINT MONDAY NIGHT. MINOR FLOODING
IS ALSO POSSIBLE AT OCEAN CITY INLET. HIGH TIDES ARE EXPECTED
AGAIN TUES...BEFORE ANOMALIES DROP OFF LATE TUES INTO TUES NIGHT
AS THE LOW LIFTS AWAY FROM THE REGION.

&&

.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 10 PM EST THIS EVENING FOR ANZ634.
     SMALL CRAFT ADVISORY UNTIL 6 AM EST SUNDAY FOR ANZ650-652-654-
     656-658.

&&

$$
SYNOPSIS...LKB
NEAR TERM...AJZ/LKB
SHORT TERM...LKB/TMG
LONG TERM...SAM
AVIATION...LSA
MARINE...SAM
TIDES/COASTAL FLOODING...SAM



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