845
FXUS61 KPBZ 170719
AFDPBZ
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
219 AM EST SAT JAN 17 2026
WHAT HAS CHANGED
CONFIDENCE REMAINS HIGH IN MODERATE-TO-HEAVY CONVECTIVE SNOW
SHOWERS LATE THIS MORNING AND AFTERNOON. SOME SHOWERS MAY BE
SQUALL-LIKE, QUICKLY DROPPING VISIBILITY AND PRODUCING BRIEFLY
HAZARDOUS TRAVEL CONDITIONS.
KEY MESSAGES
1) WINTER WEATHER ADVISORY THROUGH THIS EVENING FOR
RIDGES/HIGHER ELEVATIONS
2) MODERATE/HEAVY CONVECTIVE SNOW SHOWERS THIS
AFTERNOON MAY CREATE HAZARDOUS TRAVEL
3) PROLONGED COLD SNAP TO BEGIN THE WEEK. COLD WEATHER
ADVISORIES LIKELY MONDAY NIGHT INTO TUESDAY MORNING FOR
DANGEROUS WIND CHILLS
4) GUSTY TO STRONG WIND POSSIBLE MONDAY. WIND ADVISORY POSSIBLE
FOR THE HIGHER TERRAIN.
DISCUSSION
KEY MESSAGE 1... WINTER WEATHER ADVISORY THROUGH THIS EVENING FOR
RIDGES/HIGHER ELEVATIONS.
SHORTWAVE- AND TERRAIN-INDUCED SNOW CONTINUES EARLY THIS
MORNING, WITH GREATEST ACCUMULATIONS EXPECTED ACROSS THE
LAURELS/ALLEGHENY MTNS AND PORTIONS OF NORTHWEST TO NORTH
CENTRAL PA. SNOW RATES EARLY THIS MORNING REMAIN RELATIVELY LOW:
AROUND 0.5 IN/HR IN THE WV RIDGES AND UP TO 0.2-0.3 IN/HR
ELSEWHERE.
AFTER SUNRISE, SNOW WILL BECOME MORE CONVECTIVE IN NATURE (MORE
ON THAT BELOW), AND MAY FEATURE A GENERAL LULL IN ACTIVITY
UNTIL THE AFTERNOON HOURS. HOWEVER, CONTINUED SOUTHWESTERLY
FLOW WILL HELP KEEP SHOWERS GOING ACROSS THE RIDGES WITH
OROGRAPHIC ENHANCEMENT. AN ADDITIONAL 1-3" IS EXPECTED ACROSS
THE LAURELS/ALLEGHENY MTNS AFTER SUNRISE.
WINDS WILL VEER MORE WESTERLY BEHIND A STRONG COLD FRONT LATER
SATURDAY AFTERNOON AND EVENING. THIS WILL ADD A LAKE ENHANCEMENT
COMPONENT TO SNOW -- POSSIBLY ACROSS THE RIDGES, BUT ESPECIALLY
FOR THE NORTHERN TIER ADVISORY, WHICH CONTINUES A LITTLE LONGER
THROUGH 1 AM SUNDAY. AN ADDITIONAL 1-2" IS EXPECTED ACROSS THE
NORTHERN TIER ADVISORY AFTER SUNRISE.
KEY MESSAGE 2... MODERATE/HEAVY CONVECTIVE SNOW SHOWERS THIS
AFTERNOON MAY CREATE HAZARDOUS TRAVEL
SYNOPTICALLY-FORCED SNOW WILL END EARLY THIS MORNING WITH A
GENERAL LULL IN ACTIVITY BY SUNRISE. A WEAK EMBEDDED SHORTWAVE
WILL THEN LIFT NORTHEAST THROUGH THE AFTERNOON, USHERING IN
COOLER TEMPERATURES ALOFT. THE COMBINATION OF 925MB-850MB
FRONTOGENESIS PLUS A SATURATED DGZ (THOUGH LIFT WILL BE BELOW
THIS LAYER) AND SBCAPE VALUES AROUND 50 J/KG FAVORS POTENTIAL
FOR ISOLATED/SCATTERED HEAVIER SNOW SHOWERS THAT COULD PRODUCE
SNOW SQUALL-LIKE CONDITIONS WITH RATES UP TO 1"/HR (HREF PEAKS
SUGGEST 20-50% PROBABILITY OF THIS RATE ACHIEVED IN A GIVEN
SHOWER). THE LACK OF STRONG SURFACE COOLING AND POTENTIAL FOR
MELTING BETWEEN SHOWERS WILL LIMIT ADDITIONAL ACCUMULATIONS, BUT
COULD CREATE BRIEF, LOCALIZED HAZARDOUS TRAVEL CONDITIONS
STRETCHING FROM SOUTHEAST OH INTO WESTERN PA. TIMING OF IMPACT
FAVORS DAYTIME HOURS, PEAKING BETWEEN 11AM-6PM.
KEY MESSAGE 3... PROLONGED COLD SNAP TO BEGIN THE WEEK
A STRONG COLD FRONT LATE THIS AFTERNOON/EVENING WILL BRING A
PROLONGED PERIOD OF SUB-FREEZING TEMPERATURE THROUGH AT LEAST
MID-WEEK. COLD CONDITIONS PEAK LATE MONDAY INTO TUESDAY MORNING
AFTER A REINFORCING SHOT OF COLD AIR BEHIND ANOTHER FRONTAL
PASSAGE/UPPER WAVE; LOW TEMPERATURE TUESDAY HAS AN 80-100%
PROBABILITY OF BEING BELOW 10 DEGREES, WITH PORTIONS OF
NORTHWEST PA AND THE HIGHER TERRAIN FAVORED TO SEE BELOW-ZERO
AIR TEMPERATURE. COMBINED WITH LINGERING BREEZY CONDITIONS,
BELOW-ZERO WIND CHILLS ARE EXPECTED FOR MOST OF TUESDAY MORNING,
BOTTOMING OUT IN THE -5 TO -20F RANGE ACROSS THE REGION. THERE
IS HIGH CONFIDENCE IN NEED FOR A COLD WEATHER ADVISORY FOR THE
AREA, AND POSSIBILITY FOR EXTREME COLD WARNING IN PORTIONS OF
THE HIGHER TERRAIN.
KEY MESSAGE 4... STRONG WIND GUSTS MONDAY
STRENGTHENING PRESSURE GRADIENT AS LOW PRESSURE PASSES TO OUR
NORTH AMID DEEPER DAYTIME MIXING WILL PRODUCT WIND GUSTS BETWEEN
35-45 MPH ON MONDAY. GUSTS COULD REACH (OR EXCEED IN EASTERN
TUCKER COUNTY) WIND ADVISORY CRITERIA. UNCERTAINTY REMAINS IN
THE DEPTH OF THE CROSSING TROUGH, AND STRENGTH OF THE SURFACE
LOW/PRESSURE GRADIENT.
AVIATION /07Z SATURDAY THROUGH WEDNESDAY/
KEY MESSAGES...
1) CIG/VIS RESTRICTIONS IN SNOW ALONG AND AHEAD OF A CROSSING
FRONT TODAY
2) BURSTS OF MODERATE TO HEAVY SNOW (BUT MORE SCATTERED)
POSSIBLE THIS AFTERNOON
------------------------------------------------------------
SCATTERED TO WIDESPREAD SNOW EARLY THIS MORNING WILL RESULT IN
IFR RESTRICTIONS AT ALL PORTS. THIS WILL LESSEN FROM WEST TO
EAST OVER THE COURSE OF THE MORNING BECOMING LARGELY LOW MVFR BY
THIS AFTERNOON WHEN LATEST ENSEMBLE GUIDANCE DROPS IFR CIG PROBS
TO <50%. THAT BEING SAID, A SHORTWAVE MOVING THROUGH THE OHIO
RIVER VALLEY IS EXPECTED TO TRIGGER MORE CONVECTIVE SNOW AHEAD
OF AN APPROACHING FRONT THIS ACROSS THE REGION, WHICH COULD
RESULT IN QUICK BURSTS OF HEAVIER SNOW AND REDUCED VISIBILITIES.
HAVE MAINTAINED TEMPOS IN LATEST TAFS TO ADDRESS THIS BUT WILL
LIKELY NEED TO ADJUST TIMING IN FURTHER UPDATES, MORE LIKELY
SLIGHTLY LATER BASED ON LATEST MODEL TRENDS.
OUTLOOK...
A REINFORCING FRONT WILL CROSS TONIGHT BRINGING ANOTHER SHOT OF
COLD AIR, BUT MOISTURE WILL BE LIMITED AS WILL SNOW SHOWER
COVERAGE. COLD UNSETTLED WEATHER CONDITIONS WILL CONTINUE INTO
NEXT WEEK.
PBZ WATCHES/WARNINGS/ADVISORIES
PA...WINTER WEATHER ADVISORY UNTIL 1 AM EST SUNDAY FOR PAZ009-015-
016.
WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR PAZ074-
076-078.
OH...NONE.
WV...WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR
WVZ510>514.
DISCUSSION...RACKLEY/FRAZIER/LUPO
AVIATION...88
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