186
FXUS61 KPBZ 171008
AFDPBZ
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
508 AM EST FRI JAN 17 2025
SYNOPSIS
SNOW TAPERS THROUGH THE PREDAWN HOURS AS LOW PRESSURE DEPARTS.
A DRY FRIDAY IS FORECAST AS HIGH PRESSURE BRIEFLY VISITS.
ANOTHER SYSTEM WILL CROSS THIS WEEKEND BEFORE A SIGNIFICANT
ARCTIC OUTBREAK BRINGS FRIGID TEMPERATURES NEXT WEEK.
NEAR TERM /UNTIL 6 PM THIS EVENING/
KEY MESSAGES:
- SEASONABLE TEMPERATURES RETURN. SNOW ENDING THIS MORNING.
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SNOW HAS LARGELY COME TO AN END THIS MORNING. THERE WILL LIKELY
BE A FEW FLURRIES IN SPOTS BUT THE THREAT HAS COME TO AN END.
THE WINTER STORM WARNING IN THE RIDGES WILL BE IN EFFECT UNTIL
7AM DUE TO A FEW LINGERING PATCHES OF SNOW. AFTER THAT, THE
THREAT SHOULD BE OVER IN THE RIDGES AS WELL. UPSTREAM OBS SHOW
DRY AIR CONTINUING TO MOVE INTO THE REGION AND THIS SHOULD
FINALLY DRY OUT THE LOW LEVEL MOISTURE.
RIDGING WILL QUICKLY BUILD ACROSS THE REGION TODAY. AS WINDS
SHIFT FROM THE SOUTH, EXPECT NEAR OR SLIGHTLY ABOVE AVERAGE
TEMPERATURES THIS AFTERNOON.
SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY NIGHT/
KEY MESSAGES:
- GRADUALLY WARMING TEMPERATURES INTO THE WEEKEND.
- CONFIDENCE IS HIGH THAT A LOW PRESSURE SYSTEM WILL BRING A
ROUND OF RAIN/WINTRY MIX/SNOW TO THE AREA ON SATURDAY
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A NEW LOW PRESSURE SYSTEM EXPECTED TO ENTER THE REGION OVERNIGHT
TONIGHT INTO EARLY SATURDAY MORNING. DUE TO DEEP WARM SOUTHWEST
FLOW, THERE IS A POTENTIAL FOR MIXED PRECIPITATION EMBEDDED
WITHIN THIS DISTURBANCE AT TIMES. INITIAL PRECIP TYPE IS GOING
TO DEPEND ON HOW FAST THE LOW-LVL WARM AIR ADVANCES AND THE
DEPTH. EVEN IF THERE IS SNOW, THE RATIOS WILL VERY LOW TO CREATE
IMPACTS. IT IS LIKELY THAT THE MIXED PRECIP WILL BE RAIN AND
SNOW AS THE WARM NOSE DOES NOT SEEM TO BE VERY STRONG. TO
SUPPORT THIS, THE NBM PROBS ARE GIVING 0% FOR ICE POTENTIAL FOR
TONIGHT AND ALSO SATURDAY NIGHT. THE PROBS REACH 50% IN THE
NORTH FOR SATURDAY NIGHT CONCERNING AN INCH OR MORE OF SNOW.
BY LATE SATURDAY NIGHT, AN APPROACHING COLD FRONT FROM THE WEST
WILL CHANGE ALL RAIN TO SNOW ACROSS EVEN THE LOWER ELEVATIONS.
LONG TERM /SUNDAY THROUGH THURSDAY/
KEY MESSAGES:
- SNOW SHOWERS CONTINUE ON SUNDAY AND MONDAY IN NORTHWEST FLOW.
- ARCTIC OUTBREAK WITH DANGEROUSLY COLD TEMPERATURES AND WIND
CHILLS LIKELY NEXT WEEK.
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LIGHT SNOW SHOWERS WILL CONTINUE WITH NORTHWEST FLOW ON SUNDAY
AND MONDAY, BUT THIS WILL LARGELY DEPEND ON ICE-FREE LAKE
SURFACES. AS LAKE ERIE NEARS FULL ICE COVERAGE, MOISTURE
AVAILABILITY MAY BE LIMITED. HOWEVER, THIS DOES NOT ACCOUNT FOR
THE SECONDARY LOW THAT DEVELOPS TO THE SOUTH AND TRACKS
NORTHEAST. AS OF RIGHT NOW, THIS BRINGS THE STORM TRACK ON A
SOUTHERLY TRAJECTORY AND IMPACTING THE WV RIDGES MORE THAN THE
REST OF THE FORECAST AREA. IT REMAINS TO BE SEEN IF THE IMPACT
TO THE PA RIDGES WILL WARRANT A HEADLINE OR NOT BUT AT THIS
TIME, THERE IS A ROUGHLY 10% POTENTIAL FOR WARNING CRITERIA IN
THE PA RIDGES AND 20% TO 30% IN THE WV RIDGES. ITS ALSO FAIR TO
POINT OUT THAT THE ENSEMBLE MEMBERS FOR THIS SUNDAY/MONDAY
SNOWFALL HAS A WIDE RANGE OF SOLUTIONS. THUS FOR NOW, WILL
MENTION THE SNOW POTENTIAL IN THE HWO.
HIGH TEMPERATURES ON SUNDAY WILL DROP BACK INTO THE 20S, WITH
COLDER WEATHER STILL TO COME.
.. EXTREME COLD MONDAY THROUGH WEDNESDAY ..
CONFIDENCE REMAINS HIGH IN A SIGNIFICANT ARCTIC OUTBREAK EARLY NEXT
WEEK. EXTREMELY LOW TEMPERATURES AND WIND CHILL TEMPERATURES ARE
EXPECTED TO IMPACT THE REGION MONDAY THROUGH WEDNESDAY. ARCTIC AIR
WILL DIP DOWN OUT OF FAR NORTHERN CANADA ACROSS THE EASTERN UNITED
STATES BEGINNING SUNDAY NIGHT.
CLUSTER ANALYSIS CONTINUES TO INDICATE A DEEPER TROUGH ACROSS THE
EASTERN UNITED STATES DURING THIS TIME PERIOD, CONTINUING THE
DEEPENING TREND SEEN IN THE PREVIOUS 24 HOURS. THIS CONTINUED
DEEPENING RAISES CONFIDENCE IN A COLDER SOLUTION ACROSS THE REGION.
LONG-RANGE GUIDANCE (NAEFS) HAS 850MB AND 700 MB TEMPERATURES EARLY
NEXT WEEK NEAR THE 1ST PERCENTILE (TEMPERATURES THIS TIME OF
YEAR ARE WARMER THAN THIS 99% OF THE TIME).
NBM MEAN HIGH TEMPERATURES EARLY NEXT WEEK CURRENTLY SIT IN THE LOW
SINGLE DIGITS. GROWING CONFIDENCE IN A COLDER SOLUTION WOULD LEAN
TOWARDS HIGH TEMPERATURES BETWEEN THIS AND A REASONABLE COLDEST
SOLUTION JUST NORTH OF 0 DEGREES. THE COLDER END OF GUIDANCE FOR LOW
TEMPERATURES CURRENTLY EYES THE MINUS TEENS. PROBABILITIES OF WIND
CHILL TEMPERATURES LESS THAN 0 DEGREES ARE ABOVE 90% FROM EARLY
MONDAY MORNING THROUGH MIDDAY WEDNESDAY.
THE TIME TO BEGIN PREPARING IS NOW. UNPROTECTED PIPES CAN FREEZE AND
BURST. PROLONGED EXPOSURE TO THE COLD MAY LEAD TO HYPOTHERMIA.
FROSTBITE CAN OCCUR IN AS LITTLE AS 30 MINUTES FOR EXPOSED SKIN. IT
IS ENCOURAGED TO BRING MOVABLE PLANTS INDOORS. EXTREME CARE IS
ENCOURAGED FOR THE PROTECTION OF PETS AND ANIMALS. RESCHEDULING ANY
EVENTS, ESPECIALLY OUTDOOR EVENTS, IS ENCOURAGED.
CLUSTERED MODELS INDICATE THE TROUGH MOVES NORTH INTO CANADA ON
WEDNESDAY AND TEMPERATURES CLIMB BUT ARE LIKELY TO REMAIN BELOW
AVERAGE FOR THIS TIME OF YEAR THROUGH THE END OF THE WEEK. WITH
CONTINUED TEMPERATURES WELL BELOW FREEZING, RIVER ICE GROWTH IS
EXPECTED TO CONTINUE ACROSS THE REGION.
AVIATION /10Z FRIDAY THROUGH TUESDAY/
LIGHT SNOW/FLURRIES HAVE MOSTLY TAPERED OFF ACROSS THE AREA THIS
MORNING, THOUGH SNOW SHOWERS CONTINUE ACROSS THE HIGHER TERRAIN.
WHILE VSBYS IMPROVE, CIGS WILL CONTINUE HOVERING AROUND LOW-END
MVFR AS SHALLOW LOW-LEVEL MOISTURE REMAINS IN PLACE.
PROBABILITIES FOR MVFR REMAIN HIGH AT 80+% THROUGH THE OVERNIGHT
HOURS WITH IFR PROBS HIGHEST AT FKL/DUJ, SO HAVE ERRED ON THE
MORE PESSIMISTIC SIDE UP THAT WAY AND INCLUDED PREVAILING IFR
CIGS. IMPROVEMENT WON'T BE SEEN UNTIL FRIDAY AFTERNOON WHEN A
RIDGE BUILDS OVERHEAD AND DRIER AIR CLEARS OUT THE LINGERING
MOISTURE IN SOUTHERLY LOW-LEVEL FLOW, AND CONDITIONS WILL
IMPROVE FROM SOUTH TO NORTH. PROBS FOR MVFR DROP OFF AT MGW
AFTER 16Z, PIT AFTER 20Z, AND FKL/DUJ AROUND 22Z.
LIGHT WIND WILL GRADUALLY BACK WEST THIS MORNING AND EVENTUALLY
SOUTH FRIDAY AFTERNOON. MIXING WILL INCREASE SUSTAINED WIND
BACK TOWARD 10 KNOTS WITH PERIODIC GUSTS TO 15-20 POSSIBLE. A
PERIOD OF LLWS IS ALSO POSSIBLE FRIDAY NIGHT WITH DECOUPLING
AND A 30-40 KNOT LOW LEVEL JET OVERHEAD.
OUTLOOK...
ANOTHER SYSTEM BRINGS RESTRICTIONS AND RAIN/SNOW BACK TO THE
AREA SATURDAY THROUGH THE WEEKEND. A STRONG ARCTIC FRONT WILL
BRING BITTER COLD TEMPERATURES NEAR OR BELOW ZERO TO THE AREA
MONDAY AND TUESDAY.
CLIMATE
A PERIOD OF ANOMALOUSLY COLD WEATHER IS EXPECTED TO PASS MONDAY
THROUGH WEDNESDAY THAT WILL CHALLENGE MANY STANDING JANUARY
TEMPERATURE RECORDS. ATTACHED BELOW ARE THE STANDING
CLIMATOLOGY FOR LOCAL SITES. PITTSBURGH HAS A FULL RECORD,
WHILE OTHER SITES ARE PARTIAL RECORDS AND MAY NOT BE FULLY
REFLECTIVE OF HISTORICAL TEMPERATURES:
JANUARY 20TH: HIGH MINIMUM LOW MINIMUM
PITTSBURGH, PA 1F (1985) -18F (1985)
WHEELING, WV 13F (1940) -1F (1940)
MORGANTOWN, WV 3F (1985) -17F (1985)
NEW PHILADELPHIA, OH -3F (1994) -22F (1994)
ZANESVILLE, OH -2F (1985) -17F (1985)
DUBOIS, PA -2F (1985) -19F (1985)
JANUARY 21ST: HIGH MINIMUM LOW MINIMUM
PITTSBURGH, PA 5F (1984) -18F (1985)
WHEELING, WV 12F (2000) -2F (1924)
MORGANTOWN, WV 2F (1985) -18F (1985)
NEW PHILADELPHIA, OH -8F (1985) -19F (1985)
ZANESVILLE, OH 7F (1985) -22F (1984)
DUBOIS, PA 0F (1985) -22F (1985)
JANUARY 22ND: HIGH MINIMUM LOW MINIMUM
PITTSBURGH, PA 10F (1961) -14F (1936)
WHEELING, WV 11F (2014) -4F (2014)
MORGANTOWN, WV 11F (2014) -5F (1984)
NEW PHILADELPHIA, OH 5F (1984) -15F (1994)
ZANESVILLE, OH 13F (2014) -11F (2011)
DUBOIS, PA 8F (2013) -11F (1984)
BELOW IS THE LOWEST DAILY HIGH AND DAILY LOW TEMPERATURES OF THE
21ST CENTURY. THIS ENCOMPASSES ALL DAYS OF ALL MONTHS RUNNING
FROM JANUARY 2000 TO PRESENT:
HIGH MINIMUM LOW MINIMUM
PITTSBURGH, PA 4F (01/07/2014) -10F (01/17/2009)
(02/20/2015)
WHEELING, WV 5F (01/07/2014) -10F (01/07/2014)
MORGANTOWN, WV 7F (01/07/2014) -9F (01/28/2014)
(01/28/2014) (01/29/2014)
NEW PHILADELPHIA, OH 6F (01/16/2009) -18F (01/28/2014)
(01/28/2014)
(02/15/2015)
ZANESVILLE, OH 6F (01/28/2014) -20F (01/29/2014)
DUBOIS, PA 0F (01/07/2014) -17F (02/16/2015)
IN ADDITION, PITTSBURGH HAS NOT SEEN A DAYTIME HIGH BELOW 4F
SINCE JANUARY OF 1994. PITTSBURGH HAS ALSO HAS NOT SEEN 2
CONSECUTIVE DAYS OF HIGH TEMPERATURES LESS THAN 10F SINCE
JANUARY OF 1997. IF YOU EXTEND THIS STATISTIC TO 3 DAYS, YOU
WOULD HAVE TO GO BACK TO FEBRUARY 1899.
THE LAST TIME PITTSBURGH'S MINIMUM TEMPERATURE WAS LESS THAN OR
EQUAL TO -5F WAS DECEMBER 2022. LAST TIME IT WAS BELOW OR EQUAL
TO -10F WAS FEBRUARY 2015. FOR 2 CONSECUTIVE DAYS OF LOWS LESS
THAN OR EQUAL -10F, YOU WOULD HAVE TO GO BACK TO JANUARY OF
1994.
PBZ WATCHES/WARNINGS/ADVISORIES
PA...WINTER STORM WARNING UNTIL 7 AM EST THIS MORNING FOR PAZ074-
076.
OH...NONE.
WV...WINTER STORM WARNING UNTIL 7 AM EST THIS MORNING FOR
WVZ511>514.
SYNOPSIS...SHALLENBERGER
NEAR TERM...SHALLENBERGER
SHORT TERM...SHALLENBERGER
LONG TERM...RACKLEY/SHALLENBERGER
AVIATION...RACKLEY
CLIMATE...MILCAREK
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