Area Forecast Discussion
Issued by NWS State College, PA

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FXUS61 KCTP 070426
AFDCTP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
1126 PM EST FRI MAR 6 2015

.SYNOPSIS...
HIGH PRESSURE WILL BUILD SOUTHEAST OVER THE STATE TONIGHT. A WEAK
AREA OF LOW PRESSURE WILL PASS NORTH OF THE REGION TONIGHT AND
SATURDAY. OVERALL THE PATTERN FAVORS MODERATING TEMPERATURES AND
NO SIGNIFICANT STORMINESS FOR THE NEXT SEVERAL DAYS.

&&

.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
LATE EVENING SATL LOOP SHOWS UPPER LVL SHORTWAVE AND ASSOC BATCH
OF CIRRUS BEGINNING TO SHIFT EAST OF THE AREA AT 03Z. AS THIS
FEATURE PASSES EAST...EXPECT CLEAR SKIES FOR THE BALANCE OF THE
NIGHT ACROSS MUCH OF CENTRAL PA. HOWEVER...NEXT SHORTWAVE OVR THE
GRT LKS WILL SPREAD CLOUDS INTO THE NW MTNS AFTER MIDNIGHT.

MAIN FORECAST CHALLENGE IN THE NEAR TERM WILL BE OVERNIGHT MIN
TEMPS. POSITION OF SFC RIDGE ACROSS SE PA WILL FAVOR THAT AREA FOR
THE COLDEST TEMPS RELATIVE TO NORMAL. IDEAL RAD COOLING SCENARIO
ACROSS THE LOWER SUSQ VALLEY WITH CLEAR SKY/CALM WIND WILL RESULT
IN ANOTHER NIGHT OF RECORD COLD. FURTHER WEST...MINS LIKELY TO BE
REACHED ARND MIDNIGHT ACROSS THE NW MTNS...JUST BEFORE CLOUDS AND
INCREASING SW BREEZE DEVELOP. OVERALL...IT LOOKS LIKE WIDESPREAD
LOWS BTWN 5-10F. HOWEVER...NORMALLY COLDER VALLEYS ACROSS THE
LOWER SUSQ VALLEY WILL DIP BLW ZERO. KTHV...ALTHOUGH NOT
REPRESENTATIVE OF THE AREA...IS ALREADY DOWN TO -4F AT 03Z AND
SHOULD BOTTOM OUT BTWN 5-10 BLW ZERO.

&&

.SHORT TERM /6 AM SATURDAY MORNING THROUGH 6 PM SATURDAY/...
A WEAK CLIPPER TRACKING ACROSS THE GRT LKS WILL SPREAD CLOUDS
INTO THE REGION DURING THE DAY WITH A BIT OF LGT SNOW/FLURRIES BY
AFTN...MAINLY NORTH OF I-80. HIGHEST /CATEGORICAL/ POPS ARE PLACED
ACROSS THE NW MTNS...WHERE OROGRAPHIC LIFT FROM SW FLOW WILL PLAY
A ROLE IN SOME LGT ACCUMS. MDL BLENDED QPF SUPPORTS A COATING TO
AN INCH ALONG PORTIONS OF THE NY BORDER...WITH PROBABLY NOTHING
SOUTH OF I-80.

SATURDAY WILL START A TEMPERATURE MODERATING TREND THAT WILL
CONTINUE INTO NEXT WEEK. HIGHS WILL TOP FREEZING OVER MUCH OF THE
REGION...AND REACH THE 30S VIRTUALLY EVERYWHERE.

&&

.LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/...
BENEATH FAST WEST TO NORTHWESTERLY FLOW ALOFT...FRONTAL WAVES
WILL MOVE ALONG THE BAROCLINIC ZONE OVER THE OHIO VALLEY
SEPARATING COLD AIR IN THE GREAT LAKES/NEW ENGLAND...AND MILDER
AIR OVER THE MISSOURI/TENNESSEE VALLEY. AT MID LEVELS THE MODELS
FEATURE MINOR TIMING AND AMPLITUDE DIFFERENCES...WHICH WILL LIKELY
CONTINUE GIVEN FAST FLOW WITH WEAK SURFACE REFLECTION. GENERALLY
THE SPREAD IS MINIMAL. THE MOST DISCERNIBLE NORTHERN STREAM H5
S/WV ENERGY AND WEAK SFC CLIPPER TYPE LOW DROPPING SOUTHEASTWARD
INTO THE GREAT LAKES SHOULD RESULT IN INCREASING SNOW SHOWERS FROM
LATER SAT THRU SUNDAY...BUT WITH SYSTEMS BEING QUITE PROGRESSIVE
AND MOISTURE REMAINING QUITE LIMITED WITH NO GULF INFLOW..WATER
EQUIVALENTS WILL BE ON THE LIGHT SIDE. MODEL QPFS ARE GENERALLY IN
DECENT AGREEMENT ON THIS SCENARIO..SO STAYED CLOSE TO THEIR
CONSENSUS SOLUTIONS WITH WATER EQUIVALENTS BELOW 0.25 INCH AND
48HR SNOWFALL AMOUNTS OF AROUND 1-2 INCHES OVER THE NW MTNS
ENDING 00Z TUESDAY. TEMPS WILL TREND GRADUALLY WARMER BUT STILL
BELOW NORMAL THROUGH MONDAY.

THE MODELS AND ENSEMBLE MEANS ARE AGREEABLE/CONSISTENT WITH THE
MAIN THEMES OF THE LARGE SCALE PATTERN INTO MIDDLE OF NEXT WEEK.
THESE INCLUDE PROGRESSIVE NRN STREAM FLOW ALONG THE US/CANADIAN
BORDER...SRN PLAINS INTO MEXICO MEAN TROUGH AND STRONG RIDGE E OF
THE BAHAMAS. GEFS AND NAEFS SHOW A BROADER VERSION OF THIS PATTERN
INTO THE SECOND HALF OF NEXT WEEK WITH ABOVE NORMAL HEIGHTS FROM
THE WRN ATLC NWWD ACROSS MUCH OF THE ERN/CNTRL CONUS INTO THE
CANADIAN ROCKIES. TEMPERATURES SHOULD CONTINUE TO TREND TO THE
UPSIDE AND REACH NEAR TO SLIGHTLY ABOVE NORMAL LEVELS INTO
MIDWEEK. ONE TREND THAT WILL NEED TO BE MONITORED IS WITH
SHORTWAVE ENERGY EJECTING NEWD FROM SRN PLAINS TROUGH INTO
CONFLUENT FLOW/UPPER JET ENTRANCE REGION OVER THE MID ATLC ON
TUESDAY. A MODEL CONSENSUS SHOWS A NWD SHIFT IN THE PCPN FIELD
WITH THE ECMWF BEING THE MOST BULLISH. WILL THE COLD AIR ON THE
RETREAT TIMING MAY BE CRUCIAL FOR DETERMINING PTYPES. PLENTY OF
TIME TO RESOLVE THE DIFFERENCES THIS IN THE COMING DAYS.

&&

.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
VFR CONDITIONS WILL CONTINUE OVERNIGHT AND INTO SATURDAY AT ALL
TERMINALS...WITH THE POSSIBLE EXCEPTION OF BRADFORD/KBFD WHERE AN
MVFR CEILING IS POSSIBLE SATURDAY AS A WEAK FRONTAL SYSTEM
APPROACHES THE AREA.

OUTLOOK...

SAT...MAINLY VFR. POSSIBLE RESTRICTIONS NORTH.

SUN-MON...MVFR WITH CHC -SHSN MAINLY NORTH AND WEST. VFR SE.

TUE-WED...NO SIG WX.

&&

.CLIMATE...
THE LOW TEMPERATURE OF 0 DEGREES THIS MORNING AT HARRISBURG IS THE
COLDEST MINIMUM TEMPERATURE ON RECORD FOR THE MONTH OF MARCH. THE
PREVIOUS COLDEST MINIMUM TEMPERATURE FOR MARCH WAS 5 DEGREES SET
IN 1984 AND 1900. THE LOW TEMPERATURE OF 0 DEGREES ALSO BROKE
THE DAILY MINIMUM TEMPERATURE RECORD. THE PREVIOUS DAILY RECORD
LOW WAS 7 DEGREES SET IN 1901. A CONTINUOUS WEATHER RECORD HAS
BEEN KEPT AT HARRISBURG SINCE 1888.

&&

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

&&

$$
SYNOPSIS...LA CORTE
NEAR TERM...FITZGERALD
SHORT TERM...FITZGERALD/LA CORTE
LONG TERM...STEINBUGL
AVIATION...GARTNER
CLIMATE...



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