Area Forecast Discussion
Issued by NWS Raleigh/Durham, NC

Current Version | Previous Version | Text Only | Print | Product List | Glossary Off
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
FXUS62 KRAH 202342
AFDRAH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
740 PM EDT SUN APR 20 2014

.SYNOPSIS...WHILE LOW PRESSURE DRIFTS OUT TO SEA...HIGH PRESSURE
WILL EXTEND DOWN THE EAST COAST THROUGH MON NIGHT. A LEE TROUGH WILL
DEVELOP OVER THE MIDDLE ATLANTIC PIEDMONT TUE...AHEAD OF A COLD
FRONT THAT WILL CROSS OUR REGION TUE NIGHT.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 740 PM SUNDAY...

THE LATEST SATELLITE AND SURFACE DATA INDICATE STRATOCUMULUS WERE
BUILDING BACK TO THE SOUTHWEST INTO THE EASTERN PIEDMONT AND
SANDHILLS. THIS PROCESS IS DUE TO THE MOIST ENE CYCLONIC LOW LEVEL
FLOW AROUND THE LOW PRESSURE JUST OFFSHORE. WE WILL UPDATE THE
FORECAST TO INDICATE CLOUDY SKIES SE... AND CLEAR NW... VARIABLY
CLOUDY IN A SMALL REGION IN THE CENTER. OTHERWISE... ONLY SLOW
MOVEMENT OF THE LOW PRESSURE SUGGESTS SLOW CLEARING FROM THE NW.
LOWS UPPER 30S TO LOWER 40S IN THE CLEAR N-NW PIEDMONT... RANGING
INTO THE MID TO UPPER 40S IN THE CLOUDY/BREEZY EASTERN ZONES.

&&

.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 230 PM SUNDAY...

FOR MONDAY/MONDAY NIGHT: STRONG PARENT HIGH OVER THE NORTHEAST WILL
RETREAT OUT INTO THE ATLANTIC...LEAVING BEHIND THE RESIDUAL DRY AIR
SURFACE RIDGE WHICH WILL WEAKEN/BREAK DOWN THROUGHOUT THE DAY.
ALOFT...MID LEVEL SHORTWAVE RIDGE WILL BUILD OVER THE AREA IN
ADVANCE OF THE PROGRESSIVE POSITIVE-TILT LONG-WAVE TROUGH
PROGRESSING EASTWARD THROUGH THE CENTRAL US. ALL OF THE FORECAST
AREA WILL FINALLY GET TO ENJOY MOSTLY SUNNY SKIES ON MONDAY...WITH
TEMPERATURES MODERATING INTO THE UPPER 60S NE TO LOWER 70S JUST
ABOUT EVERYWHERE ELSE.

EXPECT AN INCREASE IN MID/HIGH LEVEL CLOUDS LATE MONDAY NIGHT WITH
THE APPROACH OF THE TROUGH INTO THE SOUTHERN/CENTRAL APPALACHIANS.
EARLIER ARRIVAL AND THICKER CLOUD COVER ACROSS THE WEST WILL HINDER
RADIATIONAL COOLING AND SUPPORT SOME OF THE WARMEST OVERNIGHT
TEMPERATURES. LOWS RANGING FROM LOWER 50S NW TO MID/UPPER 40S EAST.
SHORTWAVE ENERGY CURRENTLY IN THE CENTRAL PLAINS WILL PROGRESS
EASTWARD THROUGH THE APPALACHIANS TO THE EASTERN SEABOARD ON
TUESDAY...WHILE ADDITIONAL SHORTWAVE ENERGY (CURRENTLY IN FAR
WESTERN CANADA) DIGS SOUTHEAST THROUGH THE GREAT LAKES AND INTO THE
NORTHERN MID-ATLANTIC. AN ATTENDANT SFC LOW WILL STRENGTHEN ACROSS
THE MID-ATLANTIC AND NEW ENGLAND ON TUE...WITH AN ASSOCIATED COLD
FRONT APPROACHING FROM THE NW LATE TUE/TUE NIGHT. ONLY BRIEF
MOISTURE RECOVERY IS EXPECTED IN ASSOC/W THIS SYSTEM AND SFC
DEWPOINTS MAY STRUGGLE TO EXCEED THE 50S. HOWEVER...RELATIVELY STEEP
MID-LEVEL LAPSE RATES AND INSOLATION MAY ALLOW FOR MARGINAL DIURNAL
DESTABILIZATION (~500 J/KG MLCAPE) TUE AFT/EVE. GIVEN DPVA
JUXTAPOSED WITH LOW LEVEL CONVERGENCE AND MARGINAL INSTABILITY...
EXPECT A CHANCE OF SHOWERS AND ISOLD STORMS...THOUGH CHANCES WILL BE
CAPPED AT 50% DUE TO UNCERTAINTY IN THE EVOLUTION OF THE UPPER LEVEL
PATTERN AND WHETHER OR NOT THE AFOREMENTIONED FACTORS WILL BE
FAVORABLE ALIGNED. DO NOT ANTICIPATE ANY CHANCE FOR SEVERE WEATHER
GIVEN MARGINAL MOISTURE/INSTABILITY AND DEEP LAYER SHEAR LESS THAN
25 KT (SUPPORTIVE OF MULTICELL ORGANIZATION)...THOUGH PERHAPS
SLIGHTLY STRONGER (CLOSER TO 30 KT) NEAR THE VA BORDER. HIGHS TUE IN
THE MID/UPPER 70S TO NEAR 80F IN THE FAR SE...WITH LOWS TUE NIGHT
RANGING FROM THE UPPER 40S (N/NW) TO LOWER/MID 50S (S/SE). -VINCENT

&&

.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
AS OF 240 PM SUNDAY...

WED-THU: EXPECT DRY CONDITIONS TO PREVAIL IN THIS PERIOD DUE TO
SYNOPTIC SUBSIDENCE ASSOC/W RISING HEIGHTS ATTENDANT AN UPPER LEVEL
RIDGE BUILDING OVER THE EASTERN CONUS. EXPECT TEMPS NEAR OR SLIGHTLY
BELOW NORMAL (HIGHS IN THE LOWER/MID 70S) ASSOC/W HIGH PRESSURE
BUILDING INTO THE REGION FROM THE NORTH.

FRI-SUN: EXPECT SOME POTENTIAL FOR CONVECTION ACTIVITY FRI AFTERNOON
INTO FRI NIGHT AS THE UPPER LEVEL PATTERN GRADUALLY SHIFTS TO BROAD
CYCLONIC FLOW ALOFT IN THE PRESENCE OF A MORE SEASONABLE MOISTURE
RETURN. AT THIS TIME...EXPECT NEAR CLIMO TEMPS AND PRECIP CHANCES IN
ASSOC/W A RELATIVELY FLAT /UNIDIRECTIONAL/ UPPER LEVEL PATTERN OVER
THE REGION NEXT WEEKEND. -VINCENT

&&

.AVIATION /00Z MONDAY THROUGH FRIDAY/...
AS OF 730 PM SUNDAY...

OFFSHORE LOW PRESSURE WILL MAINTAIN CONTINUED NORTHEASTERLY FLOW
OVER CENTRAL NC...BREEZIEST AND MOST MOIST OVER THE COASTAL
PLAIN...THROUGH EARLY MONDAY. VFR CONDITIONS THIS EVENING...RANGING
FROM CLEAR SKIES AT TRIAD TERMINALS; TO 5000-6000 FT CEILINGS AT
RDU; TO 3500-5000 FT CEILINGS AT RWI AND FAY...WILL PREVAIL
THROUGHOUT THE TAF PERIOD...WITH ONE EXCEPTION. CEILINGS WILL LIKELY
LOWER INTO IFR-MVFR RANGE LATE TONIGHT-EARLY MON AT RWI AND POSSIBLY
AS FAR WEST AS FAY...AS THE RESIDUALLY MOIST LOW LEVELS OVER EASTERN
NC NOCTURNALLY COOL. OTHERWISE...THE NORTHEASTERLY FLOW WILL
GRADUALLY SUBSIDE...PARTICULARLY MIDDAY MON ONWARD...AS THE OFFSHORE
LOW MOVES AWAY AND LOSES INFLUENCE OVER THE CAROLINAS.

OUTLOOK: THE PASSAGE OF A COLD FRONT WILL RESULT IN SCATTERED
SHOWERS AND THUNDERSTORMS - AND ASSOCIATED BRIEF SUB-VFR CONDITIONS -
TUE AFTERNOON AND EVENING...FOLLOWED BY BREEZY POST-FRONTAL
NORTHWESTERLY WINDS WED. ANOTHER COLD FRONT WILL PROVIDE A CHANCE OF
SHOWERS AND STORMS AGAIN ON FRI.

&& &&

.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$

SYNOPSIS...BADGETT
NEAR TERM...BADGETT
SHORT TERM...VINCENT
LONG TERM...VINCENT
AVIATION...MWS/CBL



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