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[Printable]
661
FXUS61 KCTP 171142
AFDCTP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
742 AM EDT WED SEP 17 2014

.SYNOPSIS...
A STRONG TROUGH OVER EASTERN NORTH AMERICA WILL SLOWLY WEAKEN
FRIDAY INTO SATURDAY BEFORE RE-INTENSIFYING SUNDAY INTO MONDAY.
OVERALL IT SHOULD BE A RELATIVELY COOL DRY PERIOD WITH A BRIEF
WARM UP OVER THE WEEKEND.

&&

.NEAR TERM /UNTIL NOON TODAY/...
WEAK HIGH PRESSURE OVER THE REGION THIS MORNING HAVE ALLOWED MANY
AREAS TO CALL RAPIDLY. A PATCH OF LOW CLOUDS HAS CAUSED SOME
TEMPERATURES TO RISE IN CENTRAL AREAS. SEVERAL LOCATIONS IN THE
NORTHERN MOUNTAINS WERE IN THE MID 30S AND PATCHY FROST IS
LIKELY IN COLDER VALLEYS.

THE PATCHY CLOUDS HAVE CAUSED SOME TEMPERATURES TO RISE IN NEAR 50
IN CENTRAL AREAS. MOST AREAS WITH CLEAR SKIES WERE IN THE 40S IN
THE SOUTHERN AREAS. PATCHY CLOUDS KEPT TEMPERATURES IN THE 50S
OVER MOST OF LANCASTER COUNTY.

PATCH FOG SETTLED INTO THE SEVERAL VALLEYS.

THE FOG AND LOW CLOUDS SHOULD BURN OFF THIS MORNING. MOST AREAS
WILL BE MOSTLY SUNNY BY LATE MORNING.

&&

.SHORT TERM /NOON TODAY THROUGH 6 PM THURSDAY/...
SHOULD BE A NICE AFTERNOON WEDNESDAY TEMPERATURES MAINLY IN THE
60S WITH SOME READINGS IN THE LOW 70S IN THE SOUTHEAST. MOSTLY
SUNNY SKIES. THE WEAK HIGH MOVES TO OUR EAST AS AND A FRONT
APPROACHES AHEAD OF A STRONGER ANTICYCLONE FORECAST TO MOVE ACROSS
THE GREAT LAKES OVERNIGHT TONIGHT INTO THURSDAY.

THE FRONT IS WEAK BUT HAS SOME VERY COLD DRY AIR BEHIND IT. IT
WILL LIKELY INCREASE THE CLOUDINESS BUT ONLY A FEW SREF MEMBERS
IMPLY VERY LIGHT QPF AMOUNTS...AND THE SREF HAS A WET BIAS. SHOULD
BE A DRY FRONTAL PASSAGE OVER MOST OF THE REGION.

AFTER A RELATIVELY WARM DAY IT SHOULD BE A COOLER AND DRIER
EVENING.

&&

.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
OVERNIGHT THURSDAY INTO FRIDAY A STRONG ANTICYCLONE PASSES JUST TO
OUR NORTH. THE PW SHOULD BE ABOUT -1 SIGMA BELOW NORMAL WITH 850
HPA TEMPERATURES ABOUT -1 SIGMA BELOW NORMAL. THIS COULD PRODUCE A
WIDESPREAD FROST AND POTENTIAL FREEZE IN THE NORTHERN MOUNTAINS.

THE HIGH RETREATS TO OUR EAST FRIDAY INTO SATURDAY. TEMPERATURES
SHOULD REBOUND NICELY FRIDAY. IT WILL BE DRY. THIS MAY SET UP
COLD AIR DAMMING SITUATION SATURDAY. PATCHY FOG AND LOW CLOUDS
POSSIBLE FRIDAY NIGHT INTO SATURDAY. IT WILL NOT BE NEARLY AS COLD
SATURDAY MORNING.

MOISTURE FROM THE WESTERN SYSTEMS WILL BE TO OUR WEST ALONG WITH A
SURGE OF 1 SIGMA ABOVE NORMAL PW VALUES. AT THIS TIME THE
RETREATING HIGH AND DRY AIR SHOULD KEEP THE SHOWER ACTIVITY TO OUR
WEST...OVER THE GREAT LAKES.

AT THIS TIME...WHAT IS LEFT OF THE MOISTURE AND ANOTHER COLD FRONT
SHOULD PUSH INTO PENNSYLVANIA SUNDAY. THE TIMING WILL LIKELY
CHANGE BUT THE FRONTAL PASSAGE IS CURRENTLY INDICATED DURING THE
DAY SUNDAY. THIS MAY BE THE BEST CHANCE OF RAIN/SHOWERS SUNDAY
PERHAPS INTO SUNDAY EVENING. THE GEFS QPF PDF IMPLIES DURING THE
DAY SUNDAY IS BEST CHANCE OF RAIN IN WEST AND INTO EVENING IN THE
EAST. VERY LIGHT RAIN INDICATED IN THE GEFS.

THE 500 HPA TROUGH BEHIND THE FRONT DEEPENS OVER THE REGION MONDAY
INTO TUESDAY. THIS CAUSES THE MODELS AND ENSEMBLES TO INDICATED
INSTABILITY SHOWERS MONDAY INTO TUESDAY. LOW POPS MAINLY IN THE
SLIGHT CHANCE RANGE. NO GOOD FOCUS FOR ANY RAIN AND THE IS
FORECAST TO REMAIN BELOW NORMAL THROUGH PERHAPS THURSDAY.

SO OVERALL...OTHER THAN THE FRONTAL RAINFALL POTENTIAL SUNDAY...IT
SHOULD BE A COOL DRY PERIOD MOST OF NEXT WEEK. THIS COULD CHANGE
SHOULD AN UNRESOLVED SHORTWAVE MOVE THROUGH THE TROUGH FORECAST
OVER THE EASTERN UNITED STATES.

&&

.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
AREAS OF PATCHY FOG/MIST HAVE SETTLED OVER THE CENTRAL AND
SOUTHWESTERN TAF SITES. JST AND AOO ARE MVFR WHERE UNV AND IPT ARE
VLIFR AND LIFR RESPECTIVELY. THIS FOG IS VERY SHALLOW AND ANY FOG
SHOULD LIFT/DISSIPATE BTWN 13Z-14Z. HIGH PRESSURE AND ASSOC DRY
AIR MASS OVER THE REGION WILL TRANSLATE TO A NEAR CERTAINTY OF VFR
CONDS AND LIGHT WINDS FOR THE REST OF THE DAY.
 PATCHY MORNING FOG...ESPECIALLY IN THE VALLEYS IS PROBABLE
THURSDAY MORNING...MAINLY IN THE NW MTNS AND THROUGH THE LOWER
SUSQ. SO LNS ARE MDT ARE POSSIBLE MVFR AND BFD POSSIBLE IFR.

OUTLOOK...
THU-FRI...PATCHY AM FOG POSSIBLE...MAINLY NORTH.
SAT-SUN...NO SIG WX EXPECTED.

&&

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

&&

$$
SYNOPSIS...GRUMM
NEAR TERM...GRUMM
SHORT TERM...GRUMM
LONG TERM...GRUMM
AVIATION...FITZGERALD/CERU




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