-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KCTP 280332
AFDCTP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
1032 PM EST FRI FEB 27 2015

.SYNOPSIS...
A LARGE AREA OF HIGH PRESSURE WILL BUILD ACROSS THE AREA FOR THE
FIRST HALF OF THE WEEKEND. A LOW PRESSURE SYSTEM WILL LIFT OUT OF
THE MIDWEST...BRINGING SNOW AND MIXED PRECIPITATION TO CENTRAL
PENNSYLVANIA SUNDAY AND SUNDAY NIGHT. A STRONGER AREA OF LOW
PRESSURE WILL LIKELY TRACK WEST OF PENNSYLVANIA IN THE MIDDLE OF
THE WEEK...PRODUCING ANOTHER ROUND OF MIXED PRECIPITATION AND
RAIN IN CENTRAL PENNSYLVANIA.

&&

.NEAR TERM /UNTIL 8 AM SATURDAY MORNING/...
1000 PM UPDATE...
TEMPS DROPPING OFF NICELY NOW TO FOLLOW THE EARLIER DIP BY
DEWPOINTS. BFD IS -5F AND MESO OBS ALL AROUND MCKEAN COUNTY ARE
-7F TO -14F. ADDITIONALLY...DUJ IS 3F...FIG 7F...AND JST 5F. THERE
IS STILL ENOUGH WIND TO KEEP EVERYONE ELSE UP FOR THE TIME BEING
BUT THE HIGH SHOULD BE RIGHT OVERHEAD IN THE MORNING AND THE HIGH
CLOUDS SHOULD NOT HAVE MUCH IF ANY EFFECT ON THE TEMPS.

645 PM UPDATE...
CLEAR SKIES AND LIGHT NW WINDS. HIGH PRESSURE NOT QUITE OVERHEAD
BUT MAY BE BY 12Z. THE WINDS SHOULD GO LIGHTER. ONLY THIN CIRRUS
SHOULD MOVE IN FROM THE SW OVERNIGHT. DEWPOINTS ARE HEADED
DOWNWARD FAST WITHOUT MELTING/EVAP FROM THE SUNLIGHT. ALL THIS
SHOULD ALLOW THE TEMPS TO PLUMMET ONCE AGAIN INTO THE NEGATIVE
DOUBLE DIGITS IN THE NWRN MTNS AND SUB- ZERO ACROSS MOST OF THE
REST OF THE AREA. REC MIN FOR THE 28TH IS -18F AT IPT AND ONLY -1F
AT MDT. MDT LOOKS RIPE...BUT WON/T GO QUITE THAT COLD - YET. WILL
REVISIT IN 3 HOURS.

PREV...
VERY THIN SCT STRATO CU REMAINS OVER PORTIONS OF THE CENTRAL AND
SOUTH CENTRAL MOUNTAINS...LAUREL HIGHLANDS AND LOWER SUSQUEHANNA
RIVER VALLEY EARLY THIS AFTERNOON AS HIGH PRESSURE AND VERY DRY
AIR BUILDS EASTWARD REMAIN ACROSS THE REGION.

A LARGE AREA OF HIGH PRESSURE WILL BUILD EAST FROM THE OHIO
VALLEY AND CLEAR OUT MOST OR ALL OF THE STRATO CU BY
DUSK...FOLLOWED BY CLEAR SKIES THIS EVENING WITH JUST SOME THIN
CIRRUS SPREADING IN FROM THE SW.

&&

.SHORT TERM /8 AM SATURDAY MORNING THROUGH 6 PM SATURDAY/...
FAIR AND STILL COLD WEATHER EXPECTED SATURDAY...AS SFC HIGH WILL
BE RIGHT OVERHEAD. A FAST-MOVING MID LVL SHORTWAVE IS PROGGED BY
ALL MDLS TO TRACK ACROSS THE AREA LATE IN THE DAY. LOW PWAT AIR
MASS WILL PRECLUDE ANY PRECIP CONCERNS. HOWEVER...CIRRUS MAY DIM
THE SUNSHINE AT TIMES. ENS MEAN 850/925MB TEMPS REMAIN WELL BLW
NORMAL FOR THE DATE...LIKELY SUPPORTING HIGHS ONLY IN THE 20-25F
RANGE.

&&

.LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/...
A RELATIVELY MILD/ACTIVE SOUTHWEST FLOW ALOFT SHOULD PREVAIL
THROUGH THE PERIOD AS THE PERSISTENT UPPER RIDGE OVER THE WRN U.S.
TEMPORARILY BREAKS DOWN. NUMEROUS SHORTWAVES WITHIN THE NRN AND
SRN STREAMS WILL MOVE EAST DURING THE PERIOD PROVIDING POTENTIAL
FOR PRECIPITATION...SOME OF IT RAIN...FOR A CHANGE.

AN ARCTIC HIGH PRESSURE SYSTEM OVER CENTRAL PA AT THE START OF
THE PERIOD WILL MOVE EAST OF THE REGION BY SUNDAY NIGHT. THE
COMBINATION OF SHORTWAVE ENERGY IN THE SRN STREAM EJECTING FROM A
TROUGH AND A DIGGING NRN STREAM TROUGH MOVING SEWD FROM SOUTH
CENTRAL CANADA TOWARD THE UPPER MIDWEST SEEMS TO DRIVE AN
EXPANDING AREA OF WAA TYPE SNOWFALL SPREADING EASTWARD SUN-MON.

WHILE THERE APPEARS TO BE LITTLE INDICATION OF A STRONG SURFACE
LOW...MODELS STILL GENERATE 0.25-0.50 INCH QPF AMTS ALONG THE
BAROCLINIC ZONE. THERMAL PROFILES SEEM TO FAVOR SNOW ACROSS THE NW
1/2 OF CENTRAL PA WITH MIXED PTYPES POSSIBLE IN THE
SOUTH/SOUTHEAST. MEDIUM RANGE...ENSEMBLE AND WPC GUIDANCE SUGGEST
SUFFICIENT QP FOR A SIGNIFICANT SNOW EVENT ACROSS PART OF CENTRAL
PA. ACCORDINGLY...HAVE ISSUED A WINTER STORM WATCH ACROSS THE
NORTHWEST MOST 5 COUNTIES STARTING LATE SATURDAY NIGHT/EARLY
SUNDAY MORNING THROUGH MONDAY MORNING.

ANOTHER NRN/SRN STREAM COMBO LOOKS TO AFFECT THE REGION MID WEEK
AS ENERGY FROM THE SRN CAL UPPER LOW BEGINS TO EJECT EWD. TIMING
DIFFERENCES ARE EVIDENT WITH THE GFS MORE BULLISH ON PCPN
RETURNING EARLY TUE VS. SLOWER ECMWF (TUE NGT). MIXED PTYPE ISSUES
ARE EXPECTED AGAIN WITH THIS NEXT SYSTEM...WITH A LEAN TOWARD
RAIN AS SIGNIFICANT WARM AIR MOVES NORTH AHEAD OF THE SYSTEM.

BEHIND THE MID WEEK SYSTEM...ANOTHER PUSH OF ARCTIC AIR WILL BRING
TEMPS AND POPS BACK WELL BELOW NORMAL FOR LATE THURSDAY INTO
FRIDAY.

&&

.AVIATION /04Z SATURDAY THROUGH WEDNESDAY/...
THE NORTHWESTERLY BREEZE WILL BECOME LIGHT AND VARIABLE
OVERNIGHT. EXPECT WIDESPREAD VFR CONDS OVERNIGHT THROUGH
SATURDAY...WITH LITTLE MORE THAN SOME HIGH CLOUDINESS PASSING
OVERHEAD.

CONDITIONS WILL DETERIORATE LATER SATURDAY NIGHT INTO SUNDAY...AS
CLOUDS THICKEN AND LOWER...AND SNOW DEVELOPS FROM WEST TO EAST
ACROSS THE AREA. THE SNOW IS EXPECTED TO CHANGE TO A WINTRY MIX
ACROSS SRN PA ON SUNDAY.

THINGS SHOULD BEGIN TO IMPROVE ON MONDAY AND REMAIN GOOD INTO
EARLY TUESDAY...BEFORE THE NEXT SYSTEM PUSHES ANOTHER ROUND OF
PRECIP AND REDUCED FLYING CONDS INTO THE AREA LATER TUE INTO WED.

OUTLOOK...

OVERNIGHT INTO SAT...GENERALLY VFR. NO SIG WX EXPECTED.

SAT NIGHT-SUN...SNOW OVERSPREADING THE AREA. PRECIP SHOULD REMAIN
ALL SNOW ACROSS NRN PA...WHILE MIXING W/ SLEET AND FREEZING RAIN
ACROSS THE SOUTH.

MON...CONTINUED CIG/VIS REDUCTIONS POSSIBLE...MAINLY AM.

TUE...VFR AM. MIXED PRECIP WITH CIG/VIS REDUCTIONS POSSIBLE LATE.

TUE NIGHT-WED...CIG/VIS REDUCTIONS CONTINUE IN WINTRY MIX/RAIN.

&&

.CLIMATE...
THE COLDEST FEBRUARY ON RECORD IS STILL LOOKING LIKELY. MONTHLY
MEAN TEMPERATURES THROUGH THE 26TH...IPT 18.2...MDT 20.7.

THE CURRENT RECORD COLDEST FEBRUARY..IPT 19.3...MDT 21.4 BOTH SET
IN 1934.

SO FAR...THIS MONTH IS THE THIRD COLDEST EVER AT IPT...AND FOURTH
COLDEST EVER AT MDT.

&&

.EQUIPMENT...
KMDT AND KIPT TEMPERATURES READING FAR TOO WARM. OBSERVER AT KMDT
REPORTED 27F AS THE MAX BASED ON BACKUP OBSERVATION AND NEAREST
NEIGHBOR. PARTS ON ORDER FOR KMDT BUT KIPT TEMP SPIKE/TROUBLE IS
NEW TODAY AND WILL BE INVESTIGATED. USING 28F FOR MAX IN KIPT
FOR TODAY 2/27 BASED ON NEAREST NEIGHBOR OBSERVATIONS.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WATCH FROM LATE SATURDAY NIGHT THROUGH MONDAY
MORNING FOR PAZ004-005-010-011-017.

&&

$$
SYNOPSIS...LAMBERT
NEAR TERM...DANGELO/LAMBERT
SHORT TERM...FITZGERALD
LONG TERM...FITZGERALD/GARTNER
AVIATION...EVANEGO
CLIMATE...LAMBERT
EQUIPMENT...DANGELO