Area Forecast Discussion
Issued by NWS Sterling, 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 KLWX 061405
AFDLWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
1005 AM EDT FRI MAY 6 2016

.SYNOPSIS...
LOW PRESSURE WILL CONTINUE TO IMPACT THE REGION TODAY BEFORE
WEAKENING AND MOVING AWAY FROM THE AREA TONIGHT INTO SATURDAY. A
COLD FRONT WILL PASS THROUGH THE REGION SUNDAY AND HIGH PRESSURE
WILL BRIEFLY BUILD OVERHEAD SUNDAY NIGHT. THE BOUNDARY WILL RETURN
NORTH AS A WARM FRONT EARLY NEXT WEEK AND IT WILL REMAIN NEARBY
THROUGH THE END OF THE WEEK.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
WIDESPREAD RAIN IS MOVING WESTWARD INTO THE I-95 CORRIDOR THIS
MORNING. EST. RAINFALL RATES OF 0.25-0.4 INCHES PER HOUR ARE
OCCURRING IN THE HEAVIEST BANDS WHICH ARE ACROSS NORTHEAST
MARYLAND INCLUDING BALTIMORE CITY. MOST RAINFALL WILL STAY STEADY
AND LEAD TO A RAINY COOL DAY HOWEVER...DUE TO SATURATED SOIL RAINFALL
RATES AND AMTS AS WELL AS RIVER GAUGES ARE BEING MONITORED
CLOSELY. LOCALIZED FLOODING CAN NOT BE RULED OUT TODAY.

BREAKS IN THE CLOUDS ARE OCCURRING IN SW VA AND INSTABILITY IS
RISING IN THAT AREA. IF BREAKS REACH THE VA HIGHLANDS AND
SHENANDOAH VALLEY BY AFTERNOON ENOUGH INSTABILITY MAY LEAD TO AN
ISOLATED THUNDERSTORM.

PREV DISCUSSION...

WET DAY IN STORE FOR THE REGION AS CLOSED UPPER LOW TRANSLATES UP
THE COAST FROM A POSITION OVER EASTERN NORTH CAROLINA EARLY THIS
MORNING TO EASTERN MARYLAND/DELAWARE/NJ BY THIS EVENING. SHIELD OF
RAIN AND SHOWERS...SOME MODERATE TO LOCALLY HEAVY AT TIMES...WILL
CONTINUE TO SPREAD NORTHWESTWARD ACROSS MUCH OF THE REGION THROUGH
THE MORNING AND PERSIST THROUGH MUCH OF THE AFTERNOON. ON WESTERN
PERIPHERY OF RAIN/SHOWERS...JUST ENOUGH INSTABILITY MAY DEVELOP TO
GENERATE A FEW ISOLATED THUNDERSTORMS ACROSS CENTRAL VA AND PARTS OF
WV. WITH VERY LOW FREEZING LEVELS AND WBZ HEIGHTS (AROUND 6000
FEET)...CAN`T RULE OUT A REPORT OR TWO OF PEA-SIZED HAIL IF ANY
THUNDERSTORMS DO DEVELOP.

NOT ANTICIPATING ANY WIDESPREAD FLOODING CONCERNS AS RAIN RATES NOT
EXPECTED TO BE EXCESSIVE...ESPECIALLY IN MORE STRATIFORM RAIN
SHIELD...AND 24 HOUR TOTAL RAINFALL SHOULD BE SHORT OF FLOOD
GUIDANCE. HOWEVER...IF ANY HEAVIER RAIN SHOWERS/STORMS DO TRAIN OVER
A PARTICULAR AREA...SOME LOCALIZED FLOODING ISSUES MAY ARISE. THUS
WILL CONTINUE TO MONITOR.

WILL BE QUITE CHILLY AGAIN TODAY UNDER CLOUDS AND RAIN...WITH HIGHS
IN THE 50S FOR MOST...PERHAPS NEAR 60F IN CENTRAL VIRGINIA.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY/...
LOW WILL BECOME VERTICALLY STACKED AND BEGIN TO FILL TONIGHT AS IT
SITS AND SPINS NEAR THE REGION. THUS SHOULD SEE RAIN SHOWERS
DECREASE IN COVERAGE ALTHOUGH CHANCES WILL CONTINUE THROUGH THE
NIGHT. MAY TRANSITION TO MORE OF A LIGHT DRIZZLE OR SOME LOW CLOUDS
AND PATCHY LIGHT FOG. LOWS IN THE UPPER 40S TO AROUND 50F.

LOW WILL FINALLY BEGIN TO DEPART ON SATURDAY WITH BRIEF PERIOD OF
BUILDING HEIGHTS AND SOME DRIER NORTHWEST FLOW DEVELOPING. LIKELY
SEE SOME BREAKS OF SUN...HOWEVER WILL CONTINUE SLIGHT TO LOW CHANCE
OF SOME LINGERING SCATTERED SHOWERS AS WELL. TEMPERATURES WILL BE ON
THE REBOUND WITH HIGHS FROM THE MID 60S TO LOW 70S.

FAST APPROACHING COLD FRONT THEN QUICKLY CROSSES THE REGION SATURDAY
NIGHT INTO EARLY SUNDAY MORNING WITH ANOTHER CHANCE OF SOME RAIN
SHOWERS. HOWEVER...THE VAST MAJORITY OF SUNDAY WILL BE DRY BEHIND
THE FRONT WITH THE MOST SUNSHINE SEEN IN DAYS. HIGHS IN THE UPPER
60S TO MID 70S.

&&

.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
HIGH PRESSURE WILL BRIEFLY BUILD OVERHEAD SUNDAY NIGHT BEFORE A
WARM FRONT PASSES THROUGH THE AREA MONDAY INTO TUESDAY. UNSETTLED
CONDITIONS ARE EXPECTED DURING THIS TIME. A SOUTHWEST FLOW BEHIND
THE WARM FRONT WILL BRING WARM AND HUMID CONDITIONS
WEDNESDAY...AND THIS MAY LEAD TO A FEW SHOWERS AND THUNDERSTORMS.

A BACKDOOR COLD FRONT WILL STALL OUT NEAR THE AREA
THURSDAY...CONTINUING TO BRING UNSETTLED CONDITIONS.

&&

.AVIATION /13Z FRIDAY THROUGH TUESDAY/...
A VARIETY OF FLIGHT CATEGORIES WILL BE SEEN THROUGH TONIGHT IN
PERIODS OF RAIN...LOW CLOUDS...AND LIGHT FOG. A MIX OF VFR/MVFR WILL
TREND DOWNWARD INTO MVFR/IFR AS RAIN AND LOW CLOUDS OVERSPREAD THE
REGION THROUGH THIS MORNING. RAIN WILL BECOME STEADY AND WIDESPREAD
FOR MOST OF THE TAF SITES FOR MUCH OF TODAY. EXCEPTION WILL BE CHO
WHERE RAIN EXPECTED TO BE MORE SHOWERY IN NATURE. ALSO CANNOT RULE
OUT A BRIEF THUNDERSTORM AT CHO. RAIN WILL TAPER OFF TO SHOWERS THIS
EVENING...BUT MVFR/IFR OR LOWER LIKELY TO CONTINUE IN LOW
CLOUDS...DRIZZLE...AND/OR LIGHT FOG. CONDITIONS THEN WILL TREND
UPWARD WITH VFR DEVELOPING SATURDAY AND SUNDAY.

WINDS WILL BE LESS THAN 10 KNOTS THROUGH SATURDAY NIGHT...STARTING
GENERALLY NORTHERLY TODAY/TONIGHT...TURNING NORTH/NORTHWEST
SATURDAY. WINDS WILL FLIP AROUND TO THE SOUTH AHEAD OF FRONT
SATURDAY NIGHT...THEN BACK TO THE NORTHWEST ON SUNDAY AND BECOME
GUSTY WITH GUSTS TO ABOUT 20 KNOTS OR SO.

A WARM FRONT WILL PASS THROUGH THE TERMINALS EARLY NEXT
WEEK...BRINGING THE CHANCE FOR A FEW SHOWERS AND THUNDERSTORMS
ALONG WITH SUBVFR CIGS AND VSBYS.

&&

.MARINE...
A BRIEF PERIOD OF SCA WINDS ARE EXPECTED EARLY THIS MORNING. WINDS
WILL RELAX AND SUB-SCA WINDS CONTINUE THROUGH SATURDAY NIGHT. A
SMALL CRAFT ADVISORY WILL LIKELY BE NEEDED SUNDAY WITH GUSTS 20-23
KNOTS OUT OF THE NORTHWEST BEHIND FRONTAL PASSAGE.

HIGH PRESSURE WILL BRIEFLY BUILD OVER THE WATERS SUNDAY NIGHT
BEFORE A WARM FRONT PASSES THROUGH THE WATERS MONDAY INTO
TUESDAY...BRINGING UNSETTLED CONDITIONS. A SOUTHWEST FLOW IS
EXPECTED BEHIND THE WARM FRONT WEDNESDAY. WINDS FOR THE MOST PART
SHOULD REMAIN BELOW SCA CRITERIA...BUT IT COULD BE CLOSE OVER
PORTIONS OF THE WATERS DUE TO THE SOUTHERLY FLOW TUESDAY INTO
WEDNESDAY.

&&

.TIDES/COASTAL FLOODING...
AS OF 645 AM FRIDAY...
TIDAL ANOMALIES REMAIN AROUND 1 TO 1.5 FEET ABOVE NORMAL THIS
MORNING. THE ASTRONOMICAL HIGH TIDE THIS MORNING IS THE HIGHER OF
THE TWO...SO THE HIGHEST WATER LEVELS ARE EXPECTED DURING THIS
TIME. AS HIGH TIDE HAS ALREADY PASSED FOR ANNE ARUNDEL AND ST
MARYS COUNTIES...THE COASTAL FLOOD WARNINGS HAVE BEEN DROPPED AND
REPLACED BY COASTAL FLOOD ADVISORIES. ELSEWHERE COASTAL FLOOD
ADVISORIES ALSO REMAIN IN EFFECT.

WITH LOW PRESSURE NEAR THE MOUTH OF THE BAY...ELEVATED WATER LEVELS
WILL CONTINUE THROUGH TONIGHT. A COASTAL FLOOD ADVISORY IS IN EFFECT
FOR THE AFTERNOON AND EVENING HIGH TIDE CYCLE ACROSS CALVERT AND ST
MARYS COUNTIES...AND IT MAY NEED TO BE EXTENDED TO INCLUDE ANNE
ARUNDEL COUNTY. THE GOOD NEWS IS THAT WATER LEVELS WILL BE
NOTICEABLY LOWER COMPARED TO THIS MORNING...CLOSER TO THE MINOR
FLOODING THRESHOLDS SINCE THE ASTRONOMICAL NORM WILL BE THE LOWER OF
THE TWO.

THERE IS MUCH LESS DIFF IN WATER LEVEL BETWEEN TIDE CYCLES IN THE
UPPER TIDAL POTOMAC. GUIDANCE SUGGESTING A PROLONGED MINOR
EVENT...AND HAVE ISSUED ONE ADVY FOR TIDE CYCLES...COVERING THRU FRI
NIGHT. BASED ON MODEL GUIDANCE...EVEN THIS MAY NOT BE LONG ENOUGH.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...COASTAL FLOOD ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR DCZ001.
MD...COASTAL FLOOD ADVISORY UNTIL 6 PM EDT THIS EVENING FOR MDZ018.
     COASTAL FLOOD ADVISORY UNTIL 10 AM EDT THIS MORNING FOR MDZ011.
     COASTAL FLOOD ADVISORY UNTIL NOON EDT TODAY FOR MDZ508.
     COASTAL FLOOD ADVISORY UNTIL 6 PM EDT THIS EVENING FOR MDZ017.
VA...COASTAL FLOOD ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR VAZ054.
WV...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 11 AM EDT THIS MORNING FOR
     ANZ531>534-539>543.

&&

$$
SYNOPSIS...BJL
NEAR TERM...MM/HAS
SHORT TERM...MM
LONG TERM...BJL
AVIATION...BJL/MM/HAS
MARINE...BJL/MM/HAS
TIDES/COASTAL FLOODING...LWX


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