FXUS62 KRAH 061630
AFDRAH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
1230 PM EDT SAT SEP 6 2008
.SYNOPSIS...TROPICAL STORM HANNA IS CURRENTLY NORTH OF THE AREA.
LINGERING RAIN IN THE NORTHERN COASTAL PLAIN WILL TAPER OFF
DURING THE NEXT 1 TO 2 HOURS.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 1230 PM EDT SATURDAY...
CONDITIONS IMPROVING VERY RAPIDLY AS HANNA LIFTS RAPIDLY NORTH.
WILL UPDATE FOR CURRENT DIMINISHING RAINFALL AND IMPROVE THE SKY
CONDITIONS SOMEWHAT. WILL ALSO EXPIRE THE HIGH WIND AND TORNADO
WATCHES...AND THE FLASH FLOOD WATCH AS WELL AS NEW FLASH FLOODING
IS NOT EXPECTED. ONGOING FLOODING WILL BE HANDLED BY FLASH
STATEMENTS TO UPDATE EARLIER FLASH FLOOD WARNINGS. WILL
RECONFIGURE A WIND ADVISORY FOR THE NORTHEAST IN HANNAS WAKE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY NIGHT/...
AS OF 350 AM SATURDAY...
WINDS WILL SUBSIDE AND CLOUDS SLOWLY DEPART THIS EVENING. AIR MASS
DRIES OUT ENOUGH SUNDAY OVER MAJORITY OF FORECAST AREA TO EXCLUDE
MENTION OF POPS. EXCEPTION WILL BE THE FAR S-SE WHERE A LINGERING
SURFACE TROUGH AND RESIDUAL MOISTURE WILL SUPPORT ISOLATED
CONVECTION. THICKNESSES SUPPORT MAX TEMPS ABOUT 5 DEGREES ABOVE
NORMAL.
ON MONDAY...MID LEVEL SHEAR AXIS ENTERS REGION WITH INCREASING LOW
LEVEL INSTABILITY (-3 TO -4 BY AFTERNOON) ALONG WITH MID LEVEL
LAPSE RATES AROUND 6 DEG C/KM. WILL MENTION SLIGHT CHANCE POPS FOR
NOW.
&&
.LONG TERM /MONDAY THROUGH SATURDAY/...
AS OF 420 AM SATURDAY...
HAVE MADE A FEW CHANGES TO THE FORECAST IN THIS PERIOD. BOTH ECMWF
AND GFS SLOWLY DRAG SURFACE BOUNDARY THROUGH THE REGION LATE TUESDAY
INTO WEDNESDAY THEN STALL BOUNDARY NEAR OR JUST SOUTH OF AREA.
MEANWHILE DRY AIR RIDGE NOSES SWD FROM PARENT HIGH OVER NEW ENGLAND.
PARENT HIGH RATHER WEAK (1027MB) BUT PATTERN SIGNALS POTENTIAL FOR
CAD EVENT. 850MB FLOW REMAIN S-SE THROUGH EVENT WHICH SHOULD RESULT
IN OVERCAST SKIES AND POTENTIAL FOR SOME RAIN. IF MODEL GUIDANCE IN
LATER RUNS REMAIN CONSISTENT...WILL NEED TO INCREASE POPS. HAVE
LOWERED TEMPS A FEW DEGREES FROM PREVIOUS FORECAST BUT IF CAD EVENT
DOES MATERIALIZE...MAX TEMPS WED AND THU MAY END UP BEING 5-7
DEGREES COOLER THAN FORECAST.
&&
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
AS OF 745 AM SATURDAY...
HANNA'S CIRCULATION CENTER IS QUICKLY TRACKING NORTH ACROSS THE
CENTRAL COASTAL PLAIN. WIDESPREAD LIFR TO IFR CEILINGS WILL CONTINUE
THROUGH MID TO LATE MORNING...WITH VISIBILITY RESTRICTIONS
RESTRICTED TO IFR IN THE HEAVIER RAIN BANDS. HIGH WIND GUSTS RANGING
FROM 45KTS AT FAY AND RWI TO 25 KNOTS AT GSO AND INT WILL BE OF
CONCERN AS WELL.
CONDITIONS WILL QUICKLY IMPROVE TO VFR FROM SOUTHWEST TO NORTHEAST
BY MIDDAY...AS HANNA'S DEEPER MOISTURE SHIELD LIFTS NORTH OF THE
AREA. MOSTLY CLEAR TO FAIR SKIES ARE EXPECTED BY THE EVENING...WITH
WINDS SUBSIDING TO 3 TO 5 KTS. THESE CONDITIONS COMBINED WITH
SATURATED SOILS WILL MAKE LOCALLY DENSE FOG OVERNIGHT...ESPECIALLY
AT RDU...RWI...AND FAY WHERE 3 TO 5 INCHES HAS FALLEN.
OTHERWISE...MOSTLY VFR CONDITIONS FORECAST FROM SUNDAY ONWARD...
WITH THE EXCEPTION OF MORNING FOG.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 4 PM EDT THIS AFTERNOON FOR NCZ008>011-
026>028-043.
&&
$$
SYNOPSIS...MLM
NEAR TERM...MLM
SHORT TERM...WSS
LONG TERM...BSD
AVIATION...BSD
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