-- Discussion containing changed information from previous version are highlighted. --
000
FXUS62 KRAH 081800
AFDRAH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
100 PM EST SAT MAR 8 2014

.SYNOPSIS...
DRY AND MILD CONDITIONS WILL PERSIST THIS WEEKEND AND
INTO THE EARLY PART OF NEXT WEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 300 AM SATURDAY...

THIS MORNINGS FREEZING TEMPERATURES AND THREAT FOR BLACK ICE HAVE
QUICKLY DISSIPATED WITH ABOVE NORMAL TEMPERATURES ANTICIPATED FOR
TODAY. WHAT A DIFFERENCE A DAY MAKES AS THE STORM THAT PROMPTED
YESTERDAYS WEATHER HAS MOVED OFFSHORE AND HAS BEEN REPLACED BY
SURFACE HIGH PRESSURE CENTERED OVER THE DEEP SOUTH. ACCOMPANYING
THIS FEATURE IS A MODEST UPPER LEVEL RIDGE THAT WILL BRING WEST
SOUTH WESTERLY UPPER LEVEL FLOW TO CENTRAL NC THROUGH TODAY. IN
ADDITION SOUTHWESTERLY SURFACE FLOW AHEAD OF A WEAK COLD FRONT WILL
PREVAIL AT THE SURFACE. THIS WARM AIR ADVECTION PATTERN...COUPLED
WITH FULL SUN...WILL ALLOW TEMPERATURES TO SKYROCKET THIS
MORNING...ENDING UP AT LEAST IN THE MID TO UPPER 60S IF NOT SOME
SCATTERED LOW 70S BY THIS AFTERNOON. THICKNESSES IN THE 1340-1350
METER RANGE SUPPORT THIS CONCLUSION AS WELL. JUST HOW HIGH WE WILL
GO TODAY WILL BE DETERMINED BY THE DEPTH OF THE MIXED LAYER WHICH
FORECAST SOUNDINGS POINT TO BEING SOMEWHERE BETWEEN 925 AND 900 MB
BY AFTERNOON IN THE EAST AND AS HIGH AS 850 OR SO IN THE TRIAD. THIS
WOULD NORMALLY HELP TO BALANCE OUT THE MAXIMUM TEMPERATURE
DISTRIBUTION BUT SOME SCATTERED LOW CLOUDS ASSOCIATED WITH THE
APPROACHING DRY COLD FRONT MAY KEEP THOSE TEMPS IN THE TRIAD A FEW
DEGREES COOLER THAN IN THE EAST. REGARDLESS 65-70 DEGREES CAN BE
EXPECTED ACROSS THE AREA. WINDS WILL BE OUT OF THE SOUTHWEST AT 5-10
KTS.

OVERNIGHT A DRY COLD FRONT...STILL ASSOCIATED WITH THE PARENT LOW
FROM THE DEPARTING WINTER STORM...WILL DROP SOUTH OVER CENTRAL NC.
FRONTAL PASSAGE IS EXPECTED TO BE DRY AND WILL BASICALLY BE A COLD
FRONT IN NAME ONLY AS THE AIRMASS DOES NOT CHANGE ALL THAT MUCH.
CANADIAN AIR REMAINS WELL TO THE NORTH AND AIR BEHIND THE FRONT IS
NOT EXPECTED TO BE ALL THAT MUCH DRIER THAN WHAT WE CURRENTLY HAVE.
THEREFORE...NOT A BIG INFLUENCE ON LOW TEMPERATURES AS LOWS TONIGHT
WILL ONLY DROP INTO THE LOW TO MID 40S WHILE WINDS GRADUALLY SHIFT
AROUND TO NORTHWESTERLY AT 5-10 KTS AFTER 6Z IN THE TRIAD AND CLOSER
TO DAYBREAK AT KFAY. A BRIEF PERIOD OF MVFR CEILINGS AND A SLIGHT
DROP IN VISIBILITIES MAY OCCUR DURING THE EARLY MORNING HOURS...WITH
THE TRIAD SITES MOST VULNERABLE TO THIS.

&&

.SHORT TERM /SUNDAY THROUGH TUESDAY/...
AS OF 300 AM SATURDAY...

NORTHERN STREAM TROUGH EXITING OFF THE NORTHERN MID-
ATLANTIC/SOUTHERN NEW ENGLAND COAST EARLY SUNDAY WILL DRIVE A WEAK
AND MOISTURE DEPRIVED COLD FRONT THROUGH THE AREA SUNDAY MORNING.
DEEP ZONAL FLOW ALOFT PREVENTS COLD AIR FROM EVER REACHING THE
CAROLINAS...WITH CENTER SURFACE RIDGE AXIS CENTERED OVER THE DEEP
SOUTH/GULF COAST REGION MAINTAINING A DRY AIR MASS THROUGH TUESDAY.
WEAK DOWNSLOPE FLOW...AIDED BY LIGHTLY SOUTHWESTERLY SURFACE FLOW
WILL PROPEL TEMPERATURES FROM THE 60S ON SUNDAY TO WELL INTO THE 70S
MONDAY AND TUESDAY.

&&

.LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/...
AS OF 300 AM SATURDAY...

MODEL SPREAD REMAINS HIGH AT THE START OF THE PERIOD...WHICH IS ON
PAR GIVEN THE SPLIT FLOW PATTERN IN PLACE ACROSS THE CONUS AND
QUESTIONABLE INTERACTION OF AN AMPLIFYING NORTHERN STREAM DROPPING
SOUTH THROUGH THE NATIONS MID-SECTION WITH THE RIO GRANDE CLOSED
UPPER LOW.

THE ECMWF STILL LIES ON THE SLOWER AND MORE DEVELOPED SIDE OF THE
ENSEMBLE SPREAD WHILE THE GFS LIES ON THE QUICKER AND LESS DEVELOPED
SIDE. WHETHER OR NOT THE NORTHERN/SOUTHERN STREAM TROUGHS WILL PHASE
WILL LIKELY REMAIN UNCERTAIN FOR A COUPLE MORE DAYS...BUT REGARDLESS
OF EVENTUAL EVOLUTION...CENTRAL NC WILL SEE INCREASING RAIN CHANCES
ON WEDNESDAY AS THE WAVY FRONT MOVES THROUGH THE AREA.

DRY BEHIND THE SYSTEM THURSDAY AND FRIDAY WITH TEMPERATURES FALLING
BELOW NORMAL.

&&

.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
-- Changed Discussion --
AS OF 100 PM SATURDAY...

24 HOUR TAF PERIOD: FAIRLY HIGH CONFIDENCE OF VFR CONDITIONS LASTING
THROUGH THE TAF PERIOD. THE EXCEPTION TO THIS COULD BE IN THE TRIAD
WHERE IT IS POSSIBLE THAT THERE COULD BE SOME MARGINAL MVFR CEILINGS
DURING THE OVERNIGHT HOURS AS A DRY COLD FRONT APPROACHES FROM THE
WEST. SREF PROBABILITIES ALSO POINT TO AN OUTSIDE CHANCE OF SOME SUB-
VFR VISIBILITIES BUT NOT CONFIDENT ENOUGH IN THIS TO INCLUDE IN THE
TAFS AT THIS TIME. OTHERWISE 5-10 KT WINDS OUT OF THE SOUTHWEST WILL
VEER TO NORTHWESTERLY/NORTHERLY AFTER FRONTAL PASSAGE WHICH IS
EXPECTED TO BE BEFORE 12 IN THE WEST AND CLOSER TO 15Z IN THE EAST.
SOME GUSTY WINDS ARE POSSIBLE SUNDAY AFTERNOON UP TO 20 KTS. THIS IS
MORE LIKELY TO OCCUR IN THE EAST THAN IN THE TRIAD. SCATTERED TO
BROKEN HIGH CLOUDS CAN BE EXPECTED LEADING UP TO AND AFTER THE
FRONTAL PASSAGE WITH SOME SCATTERED 3-5 KFT CLOUDS COMING IN NEAR
THE END OF THE TAF PERIOD.

LONG TERM: ONLY REAL CHANCE FOR SOME ADVERSE CONDITIONS WILL BE
TUESDAY NIGHT INTO WEDNESDAY WITH A LOW PRESSURE SYSTEM. SUB-VFR
CONDITIONS COULD LINGER INTO THURSDAY BEFORE RETURNING TO VFR FOR
THE END OF THE WEEK.
-- End Changed Discussion --

&&

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

&&

$$
SYNOPSIS...CBL
NEAR TERM...ELLIS
SHORT TERM...CBL
LONG TERM...CBL
AVIATION...ELLIS