Area Forecast Discussion
Issued by NWS Wakefield, VA

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000 FXUS61 KAKQ 161700 AFDAKQ AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WAKEFIELD VA 100 PM EDT WED APR 16 2014 .SYNOPSIS... COOL HIGH PRESSURE BUILDS IN FROM THE NORTHWEST THIS MORNING AND SETTLES OVER THE MID ATLANTIC AND NORTHEAST STATES THIS AFTERNOON THROUGH TONIGHT. THE HIGH WILL BECOME CENTERED FROM NEW ENGLAND TO THE CANADIAN MARITIMES THURSDAY AND FRIDAY...MAINTAINING NORTHEAST FLOW AND MUCH COOLER THAN AVERAGE TEMPERATURES ACROSS THE REGION. && .NEAR TERM /THROUGH TONIGHT/... LATEST ANALYSIS SHOWING SFC HIGH PRESSURE CENTERED FROM MI SOUTH INTO NORTHERN KY...AND BEGINNING TO RIDGE EAST OF THE APPALACHIANS EARLY THIS MORNING. WINDS REMAIN GUSTY...PARTICULARLY ALONG THE COAST DUE TO RAPID PRESSURE RISES AND STRONG COLD ADVECTION BUT WIND SPEEDS HAVE DROPPED OFF SOMEWHAT OVER THE PAST FEW HRS. SKIES HAVE GENLY CLEARED EXCEPT ACRS HAMPTON ROADS AND NE NC WHERE BKN CLOUD COVER PERSISTS THROUGH MID MORNING. PERHAPS EVEN MORE IMPRESSIVE WILL BE HOW COLD TODAY`S HIGHS WILL BE EVEN WITH AMPLE SUNSHINE. LOW LEVEL THICKNESSES SUGGEST GUIDANCE VALUES OF THE MID-UPPER 40S AT THE IMMEDIATE COAST TO THE LOWER 50S OVER INTERIOR SOUTHERN VA SHOULD BE ABOUT AS WARM AS IT WILL GET (THIS IS AROUND 20 F BELOW AVG). HAVE INCLUDED A CLIMATE SECTION AS THIS MAY RIVAL RECORD LOW MAXIMUM TEMPS AT NORFOLK. HIGH PRESSURE SETTLES OVER THE AREA LATER THIS AFTERNOON INTO THIS EVENING AND WINDS WILL SUBSIDE. WILL LIKELY NEED ANOTHER FREEZE WARNING FOR PORTIONS OF THE AREA TONIGHT/THU MORNING. WITH SW FLOW ALOFT AND THE SFC HIGH BECOMING CENTERED OVER NORTHERN NEW ENGLAND OVERNIGHT...THERE WILL TEND TO BE INCREASING LOW LEVEL MOISTURE AND CLOUD COVER FROM THE SE. BUFKIT SOUNDINGS SHOW INCREASING LOW LEVEL MOISTURE ACRS SE VA AND NE NC OVERNIGHT SO TEMPS SHOULD REMAIN WELL ABOVE FREEZING THERE (LOWS IN UPPER 30S TO LOWER 40S)...WITH A FREEZE MORE PROBABLE OVER CENTRAL AND SOUTH CENTRAL VA WHERE SKIES GENLY STAY MOSTLY CLEAR AND WINDS DECOUPLE. && .SHORT TERM /THURSDAY THROUGH FRIDAY/... THE TREND THAT STARTS TONIGHT/EARLY THU MORNING LOOKS TO CONTINUE ON THU. SETUP SUPPORTS A STRONG INVERSION ABOVE 900 MB WHICH WILL TEND TO TRAP ANY DEVELOPING MARINE LAYER CLOUDINESS. NOT MUCH CHANCE FOR MEASURABLE PRECIP GIVEN A VERY DRY AIRMASS ABOVE THE INVERSION...BUT DO THINK SKIES WILL END UP MOSTLY CLOUDY OVER MOST OF THE CWA FROM I-95 EAST. THIS WILL KEEP HIGHS WELL BELOW AVG...MAINLY IN THE LOWER TO MID 50S...WITH UPPER 50S TO AROUND 60 F OVER THE PIEDMONT. A DEEPER LAYER OF MOISTURE FROM 950 TO ABOUT 800 MB WILL EVENTUALLY MOVE INTO ALL AREAS THU NIGHT/FRI AS A COASTAL TROUGH CONTINUES TO PUSH CLOSER TO THE COAST. WILL CARRY A SLIGHT CHANCE (20%) POPS THU NIGHT THROUGH FRI. WHILE THE OVERALL AIRMASS WARMS QUITE A BIT ON FRI...HAVE SIDED ON COOLER EDGE OF GUIDANCE FOR HIGHS DUE TO CLOUDS AND PERSISTENT NE FLOW. LOWS MAINLY IN THE 40S THU NIGHT WITH HIGHS FRI GENLY 55-60 F. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... AN AREA OF SFC LOW PRESSURE IS EXPECTED TO DEVELOP ON A STALLED BOUNDARY OFF THE SOUTHEAST COAST FRI NIGHT. THE LOW SHOULD TRACK NE WELL OFF THE CAROLINA COAST ON SAT. THIS FEATURE MAY BRING A FEW RAIN SHOWERS TO FAR SE VA/NE NC DURING THIS TIMEFRAME. MEANWHILE...AN UPPER LEVEL TROUGH OVER THE UPPER MIDWEST WILL SWING INTO THE ERN GREAT LAKES FRI NIGHT AND SKIRT ACROSS NRN VA ON SAT. A WEAK SFC LOW WILL BE ASSOCIATED WITH THIS FEATURE AND MAY BRING A BRIEF ROUND OF SHOWERS TO FAR NRN PORTIONS OF THE FA (INCLUDING THE MD/VA EASTERN SHORE) SAT AFTN/EARLY EVENING BEFORE MOVING OFFSHORE AND DISSIPATING. THE SFC LOW ASSOCIATED WITH THE GREAT LAKES TROUGH IS EXPECTED TO PHASE WITH THE AFOREMENTIONED COASTAL LOW SAT NIGHT...BUT THIS SHOULD OCCUR OVER NEW ENGLAND AND HAVE VERY LITTLE IMPACT TO THE MID ATLANTIC STATES. SFC HIGH PRESSURE BUILDS INTO THE REGION SUN...THEN SLIDES OFFSHORE BY SUN EVENING AS A RELATIVELY FLAT (WEST TO EAST ORIENTED) FRONTAL BOUNDARY SAGS DOWN INTO THE AREA MON NIGHT INTO TUE. WEAK SHORTWAVE ENERGY AND A SUBSEQUENT SFC LOW TRAVELING ALONG THIS BOUNDARY MAY BRING ANOTHER SHOT OF PRECIPITATION TO THE AREA ON MON/TUE. GFS PRECIP-GENERATION AND GENERAL MOVEMENT IS A BIT AGGRESSIVE VERSUS THE ECMWF...THEREFORE TRIED TO SPLIT THE DIFFERENCE WITH THE POP FORECAST AND LIMITED COVERAGE TO NO HIGHER THAN 40 PERCENT. TEMPERATURES ARE EXPECTED TO BE STRAIGHT-FORWARD SAT NIGHT THROUGH SUN NIGHT AS HIGH PRESSURE CROSSES THE REGION. EXPECT LOWS NEAR NORMAL BOTH NIGHTS IN THE 40S (LOWER 50S POSSIBLE IMMEDIATE SE VA/NE NC COASTS). HIGHS SAT/SUN RANGE FROM ROUGHLY 65 DEGREES FAR NE TO 70 DEGREES SW. AS THE FLAT FRONTAL BOUNDARY STARTS TO SAG INTO THE MID ATLANTIC STATES MON THROUGH TUE...THE TEMP FORECAST BECOMES TRICKY IN REGARD TO WHERE EXACTLY THE WARM SECTOR DEVELOPS. WITH PRECIP EXPECTED TO APPROACH THE AREA ON MON...INCREASING CIRRUS SHOULD KEEP HIGH TEMPS IN THE UPPER 60S WEST OF I-95 WITH WARMER TEMPS IN THE LOWER 70S EAST OF I-95 (MID-UPPER 60S MD/VA EASTERN SHORE). HIGHS TUE SHOULD BE IN THE LOWER 70S INLAND AND IN THE UPPER 60S NEAR THE IMMEDIATE CHES BAY AND ATLANTIC COASTS. LOW TEMPERATURES AREAWIDE ON MON/TUE NIGHT SHOULD ALSO BE WARM WITH READINGS IN THE 50S (OR ABOUT 10 DEGREES ABOVE NORMAL). && .AVIATION /18Z WEDNESDAY THROUGH MONDAY/... A MAINLY CLEAR SKY IS EXPECTED THROUGH THURSDAY MORNING. N WINDS GUSTING TO OVER 20 KNOTS WILL BECOME NE AND DIMINISH OVR MOST OF THE AREA LATER THIS AFTN INTO EARLY THIS EVENG...AS THE HI BLDS OVR THE REGION THEN SHIFTS INTO NEW ENGLAND. NE WINDS WILL REMAIN AT 10 TO 15 KT AT ORF AND ECG TNGT THRU THU...AS THE HI STRENGTHENS OVR NRN NEW ENGLAND INTO THE CANADIAN MARITIMES. NE OR E FLO WILL PUSH SC DECK OF CLOUDS BACK INTO THE AREA LATE WED NGT THRU THU. && .MARINE...
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UPDATE...REMAINING GALE WARNINGS HAVE BEEN CONVERTED INTO SCA FLAGS THROUGH AT LEAST EARLY THURSDAY MORNING. AS HIGH PRESSURE SLIDES ACROSS NEW ENGLAND TONIGHT INTO FRIDAY...WINDS TURN TO THE NE AND RESULT IN PERSISTENT SEAS OF 5 FT OR HIGHER. ANOTHER BUT WEAKER PUSH OF COLD AIR IS ANTICIPATED TO OCCUR OVERNIGHT INTO EARLY THURSDAY...WHICH WILL INCREASE WINDS INTO SCA THRESHOLDS DURING THIS TIME. IT IS LIKELY THAT SCA CONDITIONS DUE TO SEAS ABOVE 5 FT WILL CONTINUE BEYOND EARLY THURSDAY MORNING. WILL HAVE A FINAL DECISION MADE REGARDING HEADLINES BY THE AFTN FORECAST PACKAGE (ISSUED BY 4 PM TODAY). PREVIOUS DISCUSSION...HI PRES SLIDES NE ACRS NEW ENGLAND AND INTO THE CANADIAN MARITIMES TNGT INTO FRI...AS A WEAK CSTL TROF DEVELOPS OFF THE SE AND MID ATLC CST. THIS WILL RESULT IN A PROLONGED PERIOD OF NE WINDS AND ELEVATED SEAS THRU THE END OF THE WEEK.
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&& .CLIMATE... RECORD LOW MAXIMUM TEMPERATURES TODAY 4/16: RIC...45 (1929) ORF...46 (1935) SBY...45 (1935) ECG...52 (1962 & 1952) RECORD LOWS THU 4/17: RIC...31 (1949) ORF...34 (1875) SBY...26 (2008) && .AKQ WATCHES/WARNINGS/ADVISORIES...
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MD...NONE. NC...NONE. VA...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 5 PM EDT THIS AFTERNOON FOR ANZ635>637. SMALL CRAFT ADVISORY UNTIL 8 AM EDT THURSDAY FOR ANZ630>634- 638-650-652-654-656-658.
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&& $$ SYNOPSIS...LKB NEAR TERM...LKB/JAB SHORT TERM...LKB/LSA LONG TERM...BMD AVIATION...TMG/LSA MARINE...BMD/TMG CLIMATE...AKQ

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