Area Forecast Discussion
Issued by NWS State College, PA

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000 FXUS61 KCTP 071212 AFDCTP AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE STATE COLLEGE PA 712 AM EST SUN FEB 7 2016 .SYNOPSIS... HIGH PRESSURE WILL PROVIDE ONE MORE FAIR AND RELATIVELY MILD DAY TODAY. A SLOW MOVING UPPER LOW WILL BRING A PROLONGED PERIOD OF UNSETTLED WEATHER STARTING LATER MONDAY AND CONTINUING AT LEAST THROUGH MID WEEK. TEMPERATURES WILL TREND COLDER WITH TIME...ENHANCED BY AN ARCTIC FRONT TOWARD THE END OF THE WEEK. && .NEAR TERM /THROUGH TONIGHT/... SKIES ARE ALMOST PERFECTLY CLEAR ACROSS THE FORECAST AREA AS WE REMAIN SANDWICHED BETWEEN CLOUDS TO THE NORTH AND SOUTH. FAIR AND MILD CONDITIONS WILL CONTINUE TODAY SQUEEZING IN ONE LAST DAY BEFORE A SLOWLY DEVELOPING UPPER LOW DROPS INTO THE EASTERN US AND BRINGS A PROLONGED PERIOD OF INCLEMENT WEATHER TO THE REGION FOR THE NEW WORK WEEK. FOR THE OVERNIGHT WE WILL BEGIN TO SEE A SLOW INCREASE IN CLOUDINESS. IT WILL STILL BE RELATIVELY MILD WITH LOWS IN THE 20S IN MOST AREAS. && .SHORT TERM /MONDAY/... CONSIDERABLE UNCERTAINTY EXISTS WITH THE ONSET OF WHAT AT LEAST INITIALLY LOOKS LIKE SOME LIGHT PRECIPITATION AS THE UPPER LOW DIGS THROUGH THE UPPER MIDWEST ON A TRACK TOWARD THE OHIO VALLEY AND EVENTUALLY NERN US. THE SREF WAS SLOWEST IN BRINGING IN THE PRECIP MONDAY...WHICH COULD ACTUALLY BE A LIGHT MIX OF RAIN AND SNOW GIVEN THE EXPECTED HIGHS IN THE 30S TO LOWER 40S. I USED OUR BLENDED MODEL POPS WHICH ARE A BIT HIGHER THAN THE DRY SREF FOR THE AFTERNOON...WITH THE BEST CHANCE OF SOME LIGHT SNOW...OR A LIGHT RAIN/SNOW MIXTURE BEING OVER WESTERN AREAS...WITH LESSER CHANCES OVER EASTERN ZONES. IN GENERAL I CUT THE ALREADY LIGHT WPC-GUIDANCE SNOWFALL AMOUNTS BY ABOUT HALF GIVEN THAT SKIN TEMPS WILL BE RELATIVELY WARM AND WITH PRECIP RATES WHICH ARE EXPECTED TO BE ON THE LIGHT SIDE. THAT USUALLY MAKES IT HARD FOR SNOW TO STICK TO MUCH MORE THAN GRASSY SURFACES...EVEN IN AREAS WHERE IT DOES NOT MIX WITH RAIN. && .LONG TERM /MONDAY NIGHT THROUGH SATURDAY/... THE LONG TERM IS EXPECTED TO BEGIN WITH A PERIOD OF UNSETTLED WEATHER...FOLLOWED BY A SHOT OF COLDER AIR FOR THE LAST HALF OF THE WEEK INTO THE WEEKEND. IT IS FAIRLY CERTAIN CENTRAL PA WILL EXPERIENCE A PROLONGED PERIOD OF LIGHT...POSSIBLY MODERATE PRECIP FOR THE EARLY PART OF THE EXTENDED PERIOD OF THE FORECAST. CONFIDENCE REMAINS LOW HOWEVER AS TO WHICH PERIOD WILL SEE THE BEST CHANCE OF SNOW AMOUNTS THAT MIGHT WARRANT HEADLINES. THE GEFS SHOWS AT BEST A 30% PROB OF HALF INCH QPF IN THE PERIOD BETWEEN 06Z AND 18Z TUESDAY. THE ECENS IS SIMILARLY LOW KEY REGARDING THE BEST PERIOD FOR ACCUM SNOW...TAKING 6 DAYS TO REACH 6 INCH TOTALS...AND THOSE ARE IN THE USUAL LAKE EFFECT AND LAUREL HIGHLAND UPSLOPE AREAS...NOT NECESSARILY ASSOCIATED WITH A SINGLE COHERENT SURFACE CYCLONE. THE 00Z GFS COMES THE CLOSEST TO ZEROING IN ON A THREAT AREA...SHOWING THE SERN 1/3 OF THE CWA UNDER THE GUN AFTER 06Z TUESDAY THROUGH 18Z...WITH AN ELONGATED SURFACE LOW HELPING SUPPORT AN AREA OF FRONTOGENETIC FORCING INTO THE LOWER SUSQ VALLEY. IT SUPPORTS THIS IDEA WITH ABOUT 12-18 HOURS OF FAIRLY STRONG EASTERLY LOW LEVEL FLOW WHICH THE GEFS IS NOT NEARLY AS ROBUST IN PORTRAYING. THE ECENS FOR THE SAME TIME FRAME HAS A MUCH LESS VIRILE DEPICTION OF THIS WRAP-BACK INTO THE SERN AREAS. THE NAM/SREF ARE SIMILARLY LESS IMPRESSIVE WITH THE POTENTIAL FOR SIG SNOW OVER SERN ZONES. IT ALL POINTS TO CONTINUING LOW CONFIDENCE IN PICKING OUT THE BEST PERIODS FOR THE MOST QPF...BUT A RELATIVELY HIGH CONFIDENCE THAT ONCE PRECIP BEGINS...IT WILL CONTINUE FOR SEVERAL FORECAST PERIODS. WHILE THE FIRST SEVERAL DAYS OF THE NEW WEEK WILL PRESENT PRECIPITATION TIMING AND AMOUNT PROBLEMS..THERE IS A HIGHER CONFIDENCE FOR MUCH COLDER AIR TO BE DELIVERED INTO THE REGION FOR THE END OF THE WEEK INTO NEXT WEEKEND. THE COLDEST AIR IN THE GEFS IS MADE TO ARRIVE THURSDAY NIGHT AND FRIDAY. THE ECENS IS EVEN COLDER BRINGING A CHUNK OF -25C/850MB AIR INTO THE REGION FOR LATER SATURDAY INTO SUNDAY. 00Z ECMWF ENSEMBLE MOS IS NOT IN YET...BUT THE 12Z RUN HAD JUST 4 ABOVE FOR A MAX IN BRADFORD NEXT SATURDAY...WITH OVERNIGHT LOWS BELOW ZERO A SURE BET. GOING TO BE A CHILLY VALENTINE`S DAY. && .AVIATION /12Z SUNDAY THROUGH THURSDAY/...
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12Z TAFS SENT. SOME FOG AT LNS AT TIMES...BUT OVERALL LOOKING AT VFR CONDITIONS TODAY. HIGH PRESSURE OVER THE AREA WILL RESULT IN JUST A FEW HIGH CLDS LATE TODAY. NICE DAY FOR EARLY FEB. A COMPLEX WEATHER PATTERN MAY RESULT IN SOME SNOW AND COLDER TEMPERATURES AFTER TODAY. OUTLOOK... MON...PM LGT SNOW POSSIBLE...ESP W MTNS. TUE...LGT SNOW POSSIBLE...ESP W MTNS. WED...IFR/MVFR IN SHSN WRN AIRSPACE. MVFR-VFR CIGS CENTRAL/EAST. SFC WIND GUSTS 20+KT FROM 270-300. THU...MVFR IN -SHSN POSSIBLE W MTNS.
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&& .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...LA CORTE NEAR TERM...LA CORTE SHORT TERM...LA CORTE LONG TERM...LA CORTE AVIATION...MARTIN

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