Area Forecast Discussion
Issued by NWS Raleigh/Durham, NC

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FXUS62 KRAH 121341
AFDRAH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
940 AM EDT SAT JUL 12 2014

.SYNOPSIS...DEEP HIGH PRESSURE WILL BUILD OVER THE REGION THROUGH
THE WEEKEND. A COLD FRONT WILL APPROACH FROM THE NORTHWEST LATE
MONDAY... THEN CROSS THE REGION TUESDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 940 AM SATURDAY...

REST OF TODAY: LITTLE CHANGE NEEDED. FOG HAS HUNG AROUND A BIT
LONGER THAN ORIGINALLY ANTICIPATED ACROSS THE EAST AND SOUTH DUE TO
THE LOW LEVEL STABILITY AND NEARLY CALM SURFACE AIR IN PLACE...
INHIBITING DISPERSION IN BOTH THE HORIZONTAL AND VERTICAL. ONCE THIS
SLOWLY LIFTS AND MIXES... EXPECT TYPICAL FLAT DAYTIME CU IN THE
UPPER REACHES OF THE MIXED LAYER... RESULTING IN MOSTLY SUNNY SKIES
FOR THE VAST MAJORITY OF THE DAY. TRADITIONAL AND CONVECTION-
ALLOWING MODELS ALL SUPPORT A DRY FORECAST... AS DO THE 12Z UPPER
AIR ANALYSES WHICH REVEAL DEEP RIDGING THROUGHOUT THE LOW AND MID
LEVELS WITH A DRY AND STABLE COLUMN. NEAREST CONVECTION IS LIKELY TO
BE TO OUR SE ALONG THE SEA BREEZE... AS WELL AS OVER THE NC
MOUNTAINS... AS NOTED ON THE LATEST SPC SSEO OUTPUT. SHORT RANGE
GUIDANCE AND CURRENT TRENDS SUGGEST HIGHS WITHIN A DEGREE OR TWO OF
90. -GIH

LOWS TONIGHT NEAR NORMAL...AROUND 70F. -VINCENT

&&

.SHORT TERM /SUNDAY AND SUNDAY NIGHT/...
AS OF 230 AM SATURDAY...

THE AFOREMENTIONED RIDGE AXIS WILL CONTINUE TO EXTEND EASTWARD INTO
THE CAROLINAS ON SUN/SUN NIGHT. HOWEVER...A DEEP UPPER LEVEL LOW
DIGGING SOUTHEAST THROUGH CENTRAL CANADA INTO THE UPPER GREAT LAKES
WILL RESULT IN STRENGTHENING CYCLONIC FLOW ALOFT ACROSS THE OH
VALLEY AND MID-ATLANTIC SUN/SUN NIGHT. AS A RESULT...EXPECT SOME
POTENTIAL FOR UPSTREAM CONVECTION TO PROPAGATE INTO THE N/NW
PIEDMONT IN ASSOC/W SMALL AMPLITUDE WAVES EMBEDDED IN CYCLONIC FLOW
ALOFT...AND WILL INDICATE A SLIGHT CHANCE OF SHOWERS AND STORMS N/NW
OF THE TRIANGLE. OTHERWISE...EXPECT CONDITIONS SIMILAR TO TODAY
ALBEIT SLIGHTLY WARMER WITH HIGHS IN THE LOWER 90S AND LOWS SUN
NIGHT IN THE LOWER 70S. -VINCENT

&&

.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 157 AM SATURDAY...

AN ANOMALOUS MID/UPPER TROUGH FOR THE MIDDLE OF SUMMER IS EXPECTED
TO BUILD OVER THE GREAT LAKES THIS PERIOD. THE MAIN COLD FRONT
ASSOCIATED WITH THIS TROUGH IS SLATED BY THE MODELS TO APPROACH THE
MOUNTAINS FROM THE NORTHWEST LATE MONDAY. A PRE-FRONTAL TROUGH IS
ALSO FORECAST MONDAY AFTERNOON AND EVENING TO BE LOCATED OVER THE
PIEDMONT. WE WILL HAVE TO RAISE POP FOR LATE MONDAY INTO MONDAY
NIGHT TO ACCOUNT FOR THESE FEATURES. IN ADDITION... A SQUALL LINE
POTENTIALLY MAY AFFECT PORTIONS OF THE REGION MONDAY EVENING OR
NIGHT FROM THE NW.

THE MAIN COLD FRONT IS THEN EXPECTED TO PUSH ACROSS OUR REGION
TUESDAY. THE HIGHEST POP MAY END UP BEING MONDAY NIGHT AND TUESDAY
FOR THIS PERIOD. MODELS ARE A BIT QUICKER WITH THE MAIN FRONTAL
PASSAGE FOR OUR REGION IN THE LATEST RUNS. IT NOW APPEARS THAT MUCH
OF THE AREA MAY BE MUCH COOLER AND DRIER BY WEDNESDAY. HOWEVER...
THE FRONT MAY LINGER NEAR THE COASTAL PLAIN OR COASTAL AREA
WEDNESDAY INTO THURSDAY... KEEPING POP UP IN THAT REGION.

OTHERWISE... MUCH MORE STABLE HIGH PRESSURE SHOULD BUILD INTO THE
REGION WED-THU. TEMPERATURES SHOULD AVERAGE A GOOD 5-10 DEGREES
BELOW NORMAL MID TO LATE WEEK. LOWS IN THE 60-65 RANGE... WITH HIGHS
80-85 W-F.

&&

.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
AS OF 730 AM SATURDAY...

ASIDE FROM MVFR-VLIFR FOG THAT WILL RAPIDLY LIFT BETWEEN 12-13Z THIS
MORNING...EXPECT VFR CONDITIONS AND LIGHT WINDS TO PREVAIL THROUGH
THE TAF PERIOD IN ASSOC/W A DRY UPPER LEVEL RIDGE EXTENDING INTO THE
REGION FROM THE WEST.

LOOKING AHEAD: VFR CONDITIONS WILL PREVAIL THROUGH SUNDAY NIGHT...
WITH THE EXCEPTION OF A POTENTIAL FOR FOG DURING THE PRE-DAWN HOURS
SUN/MON (FAY/RWI TERMINALS) AND A POTENTIAL FOR ISOLD SHOWERS AND
STORMS AT THE INT/GSO TERMINALS SUNDAY AFT/EVE. WIDESPREAD SHOWERS
AND THUNDERSTORMS ARE EXPECTED MONDAY AND TUESDAY AS CYCLONIC FLOW
ALOFT DEVELOPS OVER THE EASTERN CONUS...PROPELLING A COLD FRONT INTO
THE MID ATLANTIC AND CAROLINAS. -VINCENT

&&

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

&&

$$

SYNOPSIS...HARTFIELD
NEAR TERM...HARTFIELD/VINCENT
SHORT TERM...VINCENT
LONG TERM...32
AVIATION...VINCENT



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