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[Printable]
453
FXUS61 KCTP 282115
AFDCTP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
515 PM EDT THU AUG 28 2014

.SYNOPSIS...
HIGH PRESSURE OVER THE UPPER GREAT LAKES WILL BUILD SOUTHEAST AND
BRING FAIR...DRY WEATHER WITH COMFORTABLE HUMIDITY THROUGH EARLY
SATURDAY. TEMPERATURES AND HUMIDITY WILL GRADUALLY INCREASE OVER
THE UPCOMING LABOR DAY WEEKEND...TRIGGERING ISOLATED TO
SCATTERED...MAINLY AFTERNOON SHOWERS AND THUNDERSTORMS.

&&

.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
SKIES ALMOST CLEAR ALREADY. SFC HIGH PRESSURE RIDGE AXIS SHOULD
CREST OVERHEAD AROUND 12Z...SO WINDS WILL GO CALM. DRY AIR WILL
THWART FOG FORMATION IN ALL BUT THE DEEPEST DARKEST VALLEYS WHERE
TEMPS COULD DROP TO 40F BY 6 AM.

&&

.SHORT TERM /6 AM FRIDAY MORNING THROUGH 6 PM FRIDAY/...
HIGH PRESSURE WILL REMAIN IN CONTROL. ANY FOG SHOULD BURN AWAY AS
THE SUN WORKS ON IT. BUT LITTLE TO NO WIND WILL MAKE IT A
WONDERFUL LATE-SUMMER DAY. TEMPS SHOULD BACK UP TO THURS MAXES
AND EVEN ADD A FEW DEGS ON - ESP IN THE WEST.

&&

.LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/...
THE MEDIUM RANGE FLOW PATTERN WILL FEATURE TROUGHING IN THE MIDWEST
AND FAIRLY HIGH HEIGHTS FCST TO PREVAIL OVER THE EAST SUPPORTED BY
A SUBTROPICAL RIDGE THAT SHOULD ANCHOR OVER THE SOUTHEAST. THIS
RIDGE WILL ALLOW HIGH PRESSURE TO CENTER OVER UPSTATE NY AT THE
START OF THE PERIOD. THIS WILL SLOWLY MOVE OFF THE NEW ENGLAND
COAST ON SATURDAY. THE BIG FORECAST QUESTION IS THE TIMING OF A
SHORTWAVE THAT SHOULD BE MOVING THROUGH THE GREAT LAKES REGION AND
INTO THE NORTHEAST LATE SATURDAY INTO SUNDAY. THE MODELS VARY ON
TIMING AND AMPLITUDE OF THIS WAVE. THE GFS/NAM PROPAGATES IT
FASTER...WHERE THE EC SLOWS THE TIMING DOWN...AND HAS A MORE ZONAL
FLOW SUNDAY INTO MONDAY. EVEN GIVEN THE INCONSISTENCIES...THERE
SHOULD BE ENOUGH MOISTURE...AND DAYTIME HEATING SHOULD BE SPURRED
ON BY A WARMING TREND WITH MAX TEMPS 5-10F ABOVE NORMAL THIS
WEEKEND AND INTO EARLY NEXT WEEK...SHOWERS AND THUNDERSTORMS
SHOULD SPARK ALONG A LONG FRONTAL BOUNDARY THAT SHOULD EXTEND IN
BETWEEN THE SYSTEMS. AS SUCH HAVE INCREASED THE CHANCE FOR
PRECIPITATION SUNDAY INTO MONDAY MORNING. THE GREATEST MOISTURE
FLUX SHOULD BE ALONG AND AHEAD OF THE FRONTAL BOUNDARY BUT IS
PROGGED TO STAY NORTH OF PA.

THE LONG RANGE PATTERN WILL BE DOMINATED BY A LARGE UPPER LEVEL
LOW CENTERED OVER THE HUDSON BAY. THIS ROTATING LOW WILL ALLOW
FOR MAINLY ZONAL FLOW THROUGH THE REGION THROUGH MID WEEK. THE GFS
AND EC IN THE LONG RANGE ARE ACTUALLY IN FAIR AGREEMENT THROUGH
THE FIRST HALF OF NEXT WEEK...THOUGH THE GFS HAS FAR MORE
AMPLITUDE IN THE WAVES...WITH DEEPER TROUGHS PROPAGATING THROUGH
PERIODICALLY...WHERE THE EC KEEPS A MORE ZONAL PATTERN. AS SUCH
HAVE LEFT CHANCE POPS DAILY THROUGH TUESDAY.

&&

.AVIATION /21Z THURSDAY THROUGH TUESDAY/...
HIGH PRESSURE OVER THE GREAT LAKES WILL BUILD SOUTHEAST INTO THE
REGION TONIGHT...BRINGING CLEAR SKIES AND A DIMINISHING WIND. A
CALM WIND AND COOL TEMPERATURES LATE TONIGHT WILL PROMOTE AREAS OF
DENSE FOG IN THE DEEP RIVER/STREAM VALLEYS OF THE ALLEGHENIES.
CLIMATOLOGY AND LATEST MOS GUIDANCE SUGGEST KBFD IS LIKELY TO
EXPERIENCE IFR/LIFR VSBYS BTWN 07Z-12Z...WHILE KAOO/KUNV/KIPT MAY
EXPERIENCE A BRIEF DIP TO IFR ARND DAWN. THE REMAINING CENTRAL PA
AIRFIELDS ARE UNLIKELY TO EXPERIENCE SIG VIS RESTRICTIONS FRI
AM...DUE TO A PERSISTENT BREEZE AT KMDT AND KLNS AND DUE TO THE
RIDGETOP LOCATION OF KJST.

ANY EARLY FOG SHOULD BURN OFF BY ARND 13Z. FOR THE REST OF
FRIDAY...THERE/S A HIGH CONFIDENCE OF VFR CONDS AND LGT WIND...AS
HIGH PRES AND DRY AIR MASS REMAIN OVR THE AREA.

OUTLOOK...
SAT...MAINLY VFR.
SUN-TUE...MAINLY VFR. SCT SHOWERS/TSTMS.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$
SYNOPSIS...DANGELO
NEAR TERM...DANGELO
SHORT TERM...DANGELO
LONG TERM...LAMBERT/CERU
AVIATION...DANGELO/FITZGERALD




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