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Area Forecast Discussion
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000
FXUS61 KCTP 041117
AFDCTP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
717 AM EDT FRI SEP 4 2015

.SYNOPSIS...
ABOVE NORMAL TEMPERATURES WILL CONTINUE INTO NEXT WEEK WITH
GRADUALLY DECREASING HUMIDITY LEVELS. ISOLATED SHOWERS AND
THUNDERSTORMS ARE POSSIBLE THIS AFTERNOON. HIGH PRESSURE WILL
ENSURE FAIR AND DRY WEATHER FOR LABOR DAY WEEKEND.

&&

.NEAR TERM /UNTIL 7 PM THIS EVENING/...
630 AM UPDATE...
LOW CLOUDS EXPANDING ACROSS THE NORTHERN HALF OF THE AREA. HAVE
TWEAKED SKY AND TEMPS FOR THIS TREND. MAXES STILL LOOK TO BE
COOLER ON THE WHOLE...BUT STILL MUCH ABOVE NORMAL. 

PREV...
THERE IS AN UPPER LEVEL LOW OVER LWR MI WHICH IS MAINLY A
WEAKNESS IN THE MASSIVE RIDGE OVERHEAD. HEIGHTS RISE TODAY OVER
THE LOWER LAKES AND NEW YORK STATE. THE RIDGE WILL END UP
SQUASHING THE LOW OFF TO THE WEST AND THE SFC HIGH SLIDES DOWN
FROM THE NORTH/NORTHEAST. DAYTIME HEAT/INSTABILITY WILL ONCE AGAIN
FIRE UP CONVECTION. THE RIDGE AND ADVANCING SFC HIGH WILL PROBABLY
SUPPRESS CONVECTION IN THE NORTH...BUT WILL STILL CARRY A VERY LOW
CHC POP THERE IN THE AFTERNOON.

THE GREATER COVERAGE OF SHRA/TSRA WILL LIKELY BE OVER THE SRN
TIER...ESPECIALLY THE LAURELS. THE EXPECTED COVERAGE WILL BE
WORTHY OF AT LEAST A 50 POP...BUT WILL KEEP THEM BELOW 60 FOR NOW.
THE WESTERN FRONT WILL ALSO BE A PLACE WHERE STORMS COULD FIRE
UP. PWATS IN THE 1.5-1.7 INCH RANGE IN THE WEST AND SOUTH TODAY
MEANS THAT A FEW CELLS COULD PRODUCE HEAVY DOWNPOURS AL A
THURSDAY.

8H TEMPS WILL RUN ABOUT 2C LOWER TODAY VS. THURS. THUS...THE MAXES
WILL PROBABLY STAY A FEW DEGS F COOLER AS WELL. WINDS REMAIN
LIGHT...BUT BECOME MORE EASTERLY THROUGH THE DAY AS THE SFC HIGH
NOSES IN FROM THE NE.

&&

.SHORT TERM /7 PM THIS EVENING THROUGH 6 PM SATURDAY/...
CONVECTION ONGOING AT THE START OF THE PERIOD MAY BE THE LAST OF
THE RAIN FOR A FEW DAYS. EXPECT SHRA/TSRA TO WANE THROUGH THE
EVENING. THE INTERESTING/CHALLENGING PART OF THIS FORECAST MAY BE
THE CLOUD COVER TONIGHT AND SAT MORNING AND RESULTANT MINS/MAXES.
THE NAM IS PRETTY AGGRESSIVE IN ADVECTING LOW CRUD/STRATUS IN FROM
THE EAST/SOUTHEAST TONIGHT AND PILING IT UP IN THE MOUNTAINS.
HOWEVER...THE GFS IS NOT SO BULLISH ON THE LOW LEVEL MOISTURE. IT
STILL MAKES LOWER CLOUDS /BELOW 8H/ BUT IS MORE NORTHEASTERLY
WITH THE WINDS ON THE SRN PERIPHERY OF THE HIGH. THUS...MORE DRY
AIR IS SEEN ADVECTING INTO THE AREA IN THE GFS SOLUTION. THIS
ALLOWS THE MARITIME AIR/CLOUDS TO DRY OUT QUICKLY WITH MINIMAL
MIXING. THE TROUBLE WITH THE DRIER SOLUTION IS THAT WE HAVE BEEN
PRETTY MUGGY AND THE MDL OMEGA FIELDS DO NOT PORTRAY SOME
OVERWHELMING DOWN-MOTION. IN FACT...THEY ARE PRETTY NEUTRAL. VERY
ISOLATED DIURNAL CONVECTION IS POSSIBLE IN THE FAR WEST/SOUTHWEST
ON SAT...BUT THE PWATS WILL BE MUCH LOWER - ONLY RANGING FROM 1
INCH IN THE NE TO 1.25 IN THE WEST. AT THIS POINT...THE MOST
PROBABLE SOLUTION IN OUR WEAK FLOW IS THAT THE SFC HIGH STAYS UP
OVER NEW ENGLAND AND THE DRY AIR MAKES ONLY SLOW PROGRESS TO MOVE
ACROSS THE REGION. WILL KEEP IT MORE CLOUDY AND COOLER IN THE
FIRST PART OF THE DAY AND KEEP MAXES SHORT OF GFS-MOS GUIDANCE.

&&

.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
NOT MUCH TO CHANGE IN A SLOWLY EVOLVING EXTENDED FORECAST. HIGH
PRESSURE SHOULD MAINTAIN DRY WEATHER SUNDAY-MONDAY. LEAD COLD
FRONT ADVANCING EWD FROM THE GREAT LAKES/MIDWEST AND POTENTIAL
ONSHORE FLOW MSTR MAY IMPACT THE FCST BY TUESDAY WITH SCT TSTMS
POSS...BUT A CONSENSUS SOLUTION HOLDS BACK HIGHER POPS UNTIL WED
OR MAYBE EVEN THU IN ASSOCIATION WITH A STRONGER SHORTWAVE/SFC
COLD FRONT. SO TIMING DIFFS WILL NEED TO BE RESOLVED AS THE RIDGE
SLOWLY BREAKS DOWN.

THE GLOBAL NUMERICAL MODELS/ENSEMBLES ARE COMING INTO BETTER
AGREEMENT ON A PATTERN CHANGE DURING THE SECOND HALF OF NEXT WEEK
WITH A SHUFFLING OF THE LONGWAVE FLOW ALLOWING EWD PROGRESSION OF
THE WESTERN TROUGH INTO THE CENTRAL STATES AND RECENT RIDGE OVER
THE EASTERN UNITED STATES OFF THE COAST INTO THE WRN ATLC. THIS
SHOULD EVENTUALLY BRING AN END TO THE RECENT HOT/DRY SPELL. A
RETURN TO SEASONAL TEMPERATURES AND MORE ACTIVE PCPN PATTERN
SEEMS PROBABLE BY NEXT WEEKEND IN THE NEW FLOW REGIME.

&&

.AVIATION /11Z FRIDAY THROUGH TUESDAY/...
LOCALLY DENSE FOG AND LOW CIGS HAVE FORMED IN THE VALLEYS OF CENTRAL
PA EARLY THIS MORNING. CONDITIONAL CLIMATOLOGY AS WELL AS LATEST
LAMP GUIDANCE SUGGEST THE FOG WILL LIFT BTWN 13Z-14Z. THE REST OF
THE DAY WILL FEATURE WIDESPREAD VFR CONDS AND LIGHT WINDS. HOWEVER...A
COLD FRONT BACKING IN FROM THE EAST WILL SPAWN SCT PM SHRA/TSRA...MAINLY
ACROSS SOUTHERN PA. A BRIEF VIS REDUCTION IS POSSIBLE IN A FEW
SPOTS FROM THESE STORMS...MAINLY BTWN 18Z-00Z.

A MOIST SERLY FLOW BEHIND THE COLD FRONT WILL LIKELY PRODUCE SOME
LOW CIGS ACROSS THE MTNS OF CENTRAL PA TONIGHT AND EARLY SAT AM. 

OUTLOOK...

SAT...AM LOW CIGS POSS...MAINLY KBFD/KJST. 

SUN-TUE...PATCHY AM FOG POSS...MAINLY KBFD/KIPT.

&&

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

&&

$$
SYNOPSIS...DANGELO/GARTNER
NEAR TERM...DANGELO
SHORT TERM...DANGELO
LONG TERM...RXR/STEINBUGL
AVIATION...FITZGERALD



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