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Pittsburgh/Western Pa Weather

north pgh

By north pgh,
in Upstate New York/Pennsylvania

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colonel717

colonel717

Posted
Posted

I'm not an expert. But looking at long range GFS model I see nothing in the way of snow all the way out to the 18-20th of Dec. It does look like colder weather at the end of that period. Sure would like some snow for Christmas though!

I am certainly no expert either. You are correct, based on the GFS the long range, prospects for snow and locking in the cold do not look good right not. Seemingly with every run the cold keeps getting pushed back. I am getting a sense of deja, deja, deja ,deja vu...First we kept hearing early Dec, then Mid-Dec, now late Dec..Sound familiar..

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blackngoldrules

blackngoldrules

Posted
Posted

Just looked at the 0600 GFS for today 12-11-2012 and for the first time it shows a low pressure system with snow & enough cold air to sustain it over the 23-24 December time frame!! First hint of snow so far. It's a ways out, but a white Christmas would be pretty nice!

Yeah, usually that far out it changes numerous times and a lot of the time doesn't happen at all. It's something to keep an eye on anyway, like you said. We also have a threat for the middle of next week as well. Even that one is still a ways out but something else to keep an eye on.

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SteelCity08

SteelCity08

Posted
Posted

Nice run on the 12z GFS for Wpa for 18-19th storm. Looks cold enough for mostly snow.

Unfortunately its nothing but a big fat rain storm on the 12gfs, but this far out temps aren't the issue. The track on the 12gfs and 18 gfs is pretty much as good as it gets around here. Definitely something to keep an eye on and our first real threat for the most part.

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RitualOfTheTrout

RitualOfTheTrout

Posted
Posted

Chances for a white Christmas look to be increasing as we get closer. The GFS continues to show a nice LES event setting up. 6z GFS also shows a weak clipper type system for Christmas eve / Christmas day. I haven't seen that (the Christmas Eve / Day) on the other runs yet so take it with a grain of salt. It will feel good to have some snow in the air and the ground for a change if we can get a favorable setup. Hopefully it will be enough to get this thread woken up!

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RitualOfTheTrout

RitualOfTheTrout

Posted
Posted

Most mets were saying that todays storm, is what would drive the pattern going forward. We would need a stronger storm today to set the pattern up. Based on todays storm as it is transpiring, is this storm stronger and helping set up a better pattern?

I think the Thursday storm is the one that is really going to change things around here for us and draw in some cold air finally.

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RitualOfTheTrout

RitualOfTheTrout

Posted
Posted

Looks like Friday we get into some decent snow showers with the wraparound.

Starting to look like a possible 1-2 inches. At least some whitening anyhow.

Both the 12z and 6z GFS are showing about .25 of lake enhanced wrap around over about a 24 - 36 hour period. If that does work out then a good 1-2 would be a reasonable expectation. Next questions then becomes can it stay cold enough for whatever we do get to hang around until Christmas?

Hopefully we can get a stronger block to keep that system after Christmas from cutting or force a Miller B type scenario. Either way, it at least looks like there will be potential storms to keep an eye on over the next 2 weeks.

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blackngoldrules

blackngoldrules

Posted
Posted

Hazardous Weather Outlook

HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE PITTSBURGH PA 347 PM EST TUE DEC 18 2012

OHZ039>041-048>050-057>059-068-069-PAZ007>009-013>016-020>023-029-031-073-075-WVZ001>004-012-021-022-192100-TUSCARAWAS-CARROLL-COLUMBIANA-COSHOCTON-HARRISON-JEFFERSON OH-MUSKINGUM-GUERNSEY-BELMONT-NOBLE-MONROE-MERCER-VENANGO-FOREST-LAWRENCE-BUTLER-CLARION-JEFFERSON PA-BEAVER-ALLEGHENY-ARMSTRONG-INDIANA-WASHINGTON-GREENE-WESTMORELAND-FAYETTE-HANCOCK-BROOKE-OHIO-MARSHALL-WETZEL-MARION-MONONGALIA-347 PM EST TUE DEC 18 2012

THIS HAZARDOUS WEATHER OUTLOOK IS FOR EAST CENTRAL OHIO...NORTHWEST PENNSYLVANIA...SOUTHWEST PENNSYLVANIA...WEST CENTRAL PENNSYLVANIA...NORTHERN WEST VIRGINIA AND NORTHERN PANHANDLE OF WEST VIRGINIA.

.DAY ONE...THIS AFTERNOON AND TONIGHT.

HAZARDOUS WEATHER IS NOT EXPECTED AT THIS TIME.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY.

WINDY CONDITIONS ARE EXPECTED LATER ON THURSDAY AND INTO FRIDAY AND GUSTS MAY CAUSE MINOR DAMAGE AND TRAVEL DIFFICULTIES FOR DRIVERS OF HIGH PROFILE VEHICLES. INITIAL FORECASTS INDICATE GUSTS OF 40 TO 45 MPH ARE POSSIBLE. SNOW SHOWERS LATE THURSDAY NIGHT INTO SATURDAY WILL BRING HAZARDOUS TRAVEL AS WELL.

.SPOTTER INFORMATION STATEMENT...

WEATHER SPOTTERS ARE ENCOURAGED TO REPORT SIGNIFICANT WEATHER CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES.

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north pgh

north pgh

Posted
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Posted

For all the years we had to suffer with brief AFDs for Pit I love the new discussions from this Fries person.

NATIONAL WEATHER SERVICE PITTSBURGH PA

904 PM EST TUE DEC 18 2012

.SYNOPSIS...

A FAST MOVING DISTURBANCE WILL BRINGS CLOUDS QUICKLY BACK INTO THE

AREA LATER THIS EVENING. HIGH PRESSURE WILL BRING DRY CONDITIONS

WEDNESDAY. LOW PRESSURE WILL THEN MOVE TOWARD THE GREAT LAKES

THURSDAY WITH A POWERFUL COLD FRONT MOVING ACROSS THE REGION

THURSDAY EVENING. THIS WILL BRING SHOWERS THURSDAY...FOLLOWED BY

WINDY AND MUCH COLDER CONDITIONS WITH SNOW SHOWERS FRIDAY AND

SATURDAY.

&&

.NEAR TERM /THROUGH WEDNESDAY/...

A BRIEF INTERLUDE OF PARTIAL CLEARING WILL MOVE ACROSS THE CWA

THIS EVENING AHEAD OF A RATHER COMPACT SYSTEM THAT IS CURRENTLY

DROPPING OF MIX OF RAIN AND SNOW OVER NORTHERN ILLINOIS...SOUTHERN

WISCONSIN...AND SOUTHWESTERN MICHIGAN ADVANCED EASTWARD OVERNIGHT.

PRECIPITATION IN ASSOCIATION WITH THE SYSTEM UPSTREAM SEEMS TO BE

RELATIVELY HIGHLY DEPENDENT UPON WHAT AMOUNTS TO A MESO-TROWAL

WITH A FAIRLY WELL DEVELOPED 850 MB LOW LEVEL THETA-E TONGUE THAT

BECOMES A MORE WELL DEFINED TROWAL UP TOWARD 700 MB. WHILE THE

MODELS WOULD INDICATE THIS SYSTEM IS CURRENTLY AT ITS MATURE PHASE

AND SHOULD DECAY AS IT ADVANCES EASTWARD...THE APEX OF THE 850

THETA-E RIDGE DOES TRACK BASICALLY RIGHT TOWARD WESTERN

PENNSYLVANIA OVERNIGHT. AS SUCH...LOW LEVEL FORCING FOR LIFT WILL

INCREASE AS WELL LOW LEVEL MOISTURE OVERNIGHT. LOOKING AT MODEL

SOUNDINGS...SATURATION HAS DIFFICULTY REACHING AS HIGH AS THE

DENDRITIC GROWTH ZONE AND TEMPERATURES SEEM LIKELY TO BE AFFECTED

BY WEAK LOW LEVEL WARM ADVECTION EVEN THOUGH WE WILL HAVE A PERIOD

OF RADIATIONAL COOLING THIS EVENING. AS SUCH...MODEL SOUNDINGS

WOULD INDICATE THE VAST MAJORITY OF THE ACTIVITY ALBEIT LIGHT THAT

DEVELOPS WOULD BE RAIN.

POPS WERE INCREASED OVERNIGHT TOWARD MORNING...AND EVEN THOUGHT

MODEL SOUNDINGS INDICATE MOSTLY RAIN...THE RADIATIONAL COOLING

WINDOW AS WELL AS SOME WET BULBING WOULD SUGGEST TO THIS

FORECASTER THAT A BIT OF SNOW MAY BE MIXED IN NORTH OF THE

TURNPIKE AS WELL AS IN THE HIGHER TERRAIN. AS SUCH...A MIX WAS

CARRIED IN THOSE LOCATIONS WITH JUST VERY LIGHT RAIN ELSEWHERE.

FRIES

&&

.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/...

-- Changed Discussion --

THE FORECAST AREA ROLLS QUICKLY INTO THE WARM SECTOR AHEAD OF THE NEXT SYSTEM TO APPROACH THE AREA. VERY WARM CONDITIONS MOVE INTO THE REGION WITH STRONG MIXING WEDNESDAY NIGHT INTO THURSDAY. MODEL SOUNDINGS FROM THE GFS AND NAM SUGGEST STRONG SOUTHWESTERLY FLOW WILL ENCOMPASS THE AREA THROUGH THURSDAY...HOWEVER THE BEST MIXING SEEMS TO WAIT FOR COLD ADVECTION THURSDAY NIGHT INTO FRIDAY. WHILE SOLIDLY IN THE WARM SECTOR...A COUPLED UPPER JET STRUCTURE MOVES THROUGH THE REGION ON THURSDAY EVENING...COINCIDENT WITH THIS...STRONG FRONTOGENETICAL LIFT PROVIDES AMPLE ASCENT AHEAD OF AN EASTWARD ADVANCING COLD FRONT TO ALLOW FOR CATEGORICAL 100 PERCENT POPS THROUGH THE LATTER HALF OF THURSDAY INTO THURSDAY EVENING. THEN THE FUN BEGINS... A FUNNY THING HAPPENS ON THE WAY TO OCCLUSION WITH THIS SYSTEM. FAIRLY STRONG AGREEMENT EXISTS ON THE AREA ENDING UP IN THE LARGE SCALE DRY SLOT ON THURSDAY NIGHT POST-FRONTAL AND POST CHANGEOVER. GENERALLY...THIS WOULD BE THE END OF THE PROMISE OF A HEAVY WINTER STORM SNOWFALL EVENT. HOWEVER...THIS TIME LOOKS TO BE A BIT DIFFERENT. THE LARGE SCALE SYSTEM ITSELF SEEMS TO REACH MATURITY OVER NORTHERN ILLINOIS ON THURSDAY WITH A WELL-DEVELOPED TROWAL AIRSTREAM CURVING CYCLONICALLY AND ASCENDING AROUND THE OCCLUDING SYSTEM ITSELF. HOWEVER...EVEN WHILE THE SYSTEM FILLS...THE TROWAL CONTINUES TO WRAP FARTHER AND FARTHER AROUND THE FIRST NORTH...THEN NORTHWEST...THEN WEST...AND EVENTUALLY SOUTHWEST PORTION OF THE SYSTEM. AS THIS OCCURS...WE ACTUALLY END UP WITH SYNOPTIC LIFT AND RESATURATION OF THE DENDRITIC LAYER ACROSS A WIDE SWATH OF THE FORECAST AREA ON FRIDAY. THIS OCCURS VIA A COMBINATION OF ISENTROPIC ASCENT AS WELL AS WEAK FRONTOGENESIS ON THE PERIPHERY OF THE TROWAL AIRSTREAM. ADDITIONALLY...BECAUSE THE TROWAL REMNANT ON THE NAM/GFS CONSENSUS LIES ROUGHLY IN THE -6 TO -14C LAYER...IT DOES MANAGE TO AT LEAST BISECT THE LOWER SECTION OF THE DENDRITIC LAYER AT THAT TIME. THIS SHOULD LEAD TO A PERIOD OF ACCUMULATING SNOW IN LOW LEVEL COLD ADVECTION FOR MOST OF THE CWA ON FRIDAY. WHILE THE TROWAL EVOLUTION AND WRAP UP OF THE LARGE SCALE SYSTEM WILL MANAGE TO KEEP THE LOW LEVEL FLOW FROM GOING NORTHWESTERLY TOO EARLY ON FRIDAY...ALL SIGNS POINT TO THAT HAPPENING IN A BIG WAY LATER IN THE DAY. WITH SECONDARY COLD ADVECTION...LOW LEVEL LAPSE RATES LOOK TO STEEPEN MARKEDLY AFTER 15Z FRIDAY. THIS WILL QUICKLY BRING THE DENDRITIC LAYER LOWER AND ALLOW FOR LOW LEVEL INSTABILITY TO WORK WITHIN THE DENDRITIC LAYER...INCREASING SNOW RATIOS MARKEDLY. ADDITIONALLY...WHEN CONSIDERING LOW LEVEL FLOW OF NEARLY 60 KTS AT ABOUT 3000 FEET...AND 850 MB COOLING TOWARD -10C YIELDS A NEARLY PERFECT OVERLAY OF INSTABILITY AND OROGRAPHIC ASCENT ALL WITHIN THE CRITICAL -12 TO -20C LAYER OF THE DENDRITIC GROWTH ZONE. AS A RESULT...WHILE QPF VALUES RAMP UP TOWARD 0.25 INCHES PER 6 HOURS...RATIOS LOOK TO EASILY EXCEED 15:1 CONSERVATIVELY. THIS SEEMS QUITE LIKELY TO RESULT IN COPIOUS SNOWFALL...EASILY IN EXCESS OF 6 INCHES FOR THE RIDGES. CURRENT BUFKIT PROJECTIONS YIELD SNOW RATIOS OF UP TO 25:1 AT TIMES AND UP TO A FOOT OF ACCUMULATION IN THE RIDGES. WHILE THIS EVENTUALITY SEEMS QUITE LIKELY...ALL PUBLIC PRODUCTS WILL BE MAINTAINED WITH 6 INCHES OR MORE WORDING FOR CONSISTENCY UNTIL A FINAL WARNING DECISION CAN BE MADE. OUTSIDE THE RIDGES...THE LOW LEVEL FLOW EVOLUTION TO NORTHWEST AFTER 18Z FRIDAY WILL LIKELY HAVE OVER RAMIFICATIONS. WITH INVERSION HEIGHTS RISING TOWARD AND EVEN ABOVE 10 KFT FRIDAY EVENING AND LAKE TO 850 MB DELTA T VALUES RUNNING AROUND 18C OR SO...INSTABILITY IN THE LAYER GETS RATHER EXTREME. CONSIDERING THAT THERE IS STILL SOME SYNOPTIC MOISTURE AVAILABLE AND LITTLE LOW LEVEL DRY ADVECTION WITH STRONG LAPSE RATES IN THE LAYER...LAKE EFFECT BANDS WILL BE LIKELY TO INCREASE LATE FRIDAY INTO FRIDAY NIGHT DOWNWIND OF LAKE ERIE. ASSUMING FLOW GOES NORTHWESTERLY ENOUGH...THESE WILL PROBABLY REQUIRE ADDITIONAL WINTER HEADLINES FOR THE I-80 CORRIDOR...AS WELL AS POSSIBLY THE SLIGHTLY HIGHER AREAS OF JEFFERSON AND INDIANA COUNTIES. AT THE MOMENT...ACCUMULATIONS IN THESE AREAS ARE PROBABLY THE MOST UNCERTAIN OF THE FORECAST. STAY TUNED TO FUTURE STATEMENTS AND PRODUCTS FROM THE NATIONAL WEATHER SERVICE FOR ADDITIONAL INFORMATION. AND ONE MORE ISSUE TO DEAL WITH...WIND. UNDER COLD ADVECTION...GFS BUFKIT SUGGESTS ABOUT 45-60 KTS AT THE TOP OF THE MIXED LAYER...PARTICULARLY FRIDAY MORNING. SHOULD THIS EVENTUALITY COME TO FRUITION AND EXTEND INTO FRIDAY WITH CONTINUALLY FALLING SNOW...BLIZZARD CONDITIONS WOULD BE LIKELY IN THE RIDGES. THE POSSIBILITY OF AN UPGRADE TO THE WINTER STORM WATCHES TO BLIZZARD WATCHES IS REAL...HOWEVER AT THIS TIME...A STRONGLY WORDED WINTER STORM WATCH WILL BE CONTINUED. FRIES

-- End Changed Discussion --

&& .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... CONSENSUS OF RECENT GFS...CMC...ECMWF AND NAEFS MODEL OUTPUT SHOW STRONG LOW PRESSURE SYSTEM EXITING NORTH OF LAKE ERIE FRIDAY NIGHT...BUT PROVIDING STRONG COLD UNSTABLE LOW LEVEL FLOW ACROSS THE UPPER OHIO VALLEY INTO SATURDAY. HENCE EXPECT BLUSTERY WESTERLY WINDS FRIDAY NIGHT INTO SATURDAY...PERHAPS EXCEEDING 40 MPH ACROSS THE MOUNTAINS...PLUS LAKE-EFFECT ORTHOGRAPHICALLY-ENHANCED SNOW SHOWERS. SO A WINTER STORM WATCH WILL BE CONTINUED FOR THE WV-MD MOUNTAINS INTO SATURDAY. ENSUING HIGH PRESSURE SHOULD PROMOTE MAINLY DRY SEASONABLY COLD CONDITIONS SUNDAY AND MONDAY. THERE IS UNCERTAINTY REGARDING THE WEATHER FOR CHRISTMAS. THE ECMWF MODEL SHOWS A DEEP LOW PRESSURE SYSTEM MOVING NORTHEASTWARD THROUGH MIDWEST AND SPREADING PRECIPITATION INTO THE UPPER OHIO VALLEY. THE GFS...LIKE MOST NAEFS MEMBERS SHOW THE LOW STILL DEVELOPING OVER THE SOUTHERN PLAINS WITH HIGH PRESSURE LINGERING ACROSS THE NORTHEASTERN U.S. SO AT THIS JUNCTURE HAVE CONTINUED DRY SEASONABLE CONDITIONS FOR CHRISTMAS DAY. SPECIFIC TEMPERATURES WERE FORECASTED USING A BLEND OF GFS AND ECMWF MOS. &&

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RitualOfTheTrout

RitualOfTheTrout

Posted
Posted

Wow not to get ahead of ourselves here but.. Did you all see the post Christmas Storm on the GFS last night?

post-328-0-38448000-1355922524_thumb.gif

post-328-0-60321500-1355922859_thumb.gif

Verbatim that is a Blizzard for SWPA, This is way out there in model time and this thing has been all over the place but its not often you see a setup / track like that. I'd love to see the hours in between!

Now back to reality. Still looks good for 1-3 inches Thursday night after the changeover through Saturday morning. Hopefully we can get some vigorous bands to overproduce and some folks get lucky.

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colonel717

colonel717

Posted
Posted

Wow not to get ahead of ourselves here but.. Did you all see the post Christmas Storm on the GFS last night?

post-328-0-38448000-1355922524_thumb.gif

post-328-0-60321500-1355922859_thumb.gif

Verbatim that is a Blizzard for SWPA, This is way out there in model time and this thing has been all over the place but its not often you see a setup / track like that. I'd love to see the hours in between!

Now back to reality. Still looks good for 1-3 inches Thursday night after the changeover through Saturday morning. Hopefully we can get some vigorous bands to overproduce and some folks get lucky.

With temps slightly above freezing until Christmas, we are going to need several inches most likely for it to be a white Christmas. Also potential for a shortwave coming thru that I see models picking up on for Christmas.. Definitly some good potential in the long range.

Nice to see some activity in our region.

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north pgh

north pgh

Posted
  • Author
Posted

Latest models have dropped the QPF for our area. It still looks like a solid 1 inch for everyone and an isolated inch or 2 more if somebody gets under a snow band. The thing that will make it bad is we haven't had any snow yet so the drivers will be awful and the winds and cold will really make if feel colder because it has been so warm.

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