102  
FXUS61 KPBZ 211536  
AFDPBZ  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE PITTSBURGH PA  
1036 AM EST TUE JAN 21 2025  
   
SYNOPSIS  
 
POTENTIALLY DANGEROUS SUB FREEZING WIND CHILLS ARE EXPECTED  
THROUGH WEDNESDAY; COLD WEATHER ADVISORY/EXTREME COLD WARNINGS  
REMAIN IN EFFECT ACROSS THE REGION. SNOW CHANCES INCREASE THIS  
AFTERNOON AND EVENING WITH A PASSING DISTURBANCE.  
 
 
   
NEAR TERM /THROUGH TONIGHT/  
 
KEY MESSAGES:  
 
- COLD WEATHER ADVISORY/EXTREME COLD WARNING IN EFFECT  
- THE POTENTIAL FOR SNOW BANDS INCREASES BETWEEN 1PM AND 6PM  
TODAY; TRAVEL MAY BE HAZARDOUS IN ISOLATED AREAS  
 
-----------------------------------------------------------------  
 
VERY COLD TEMPERATURES ARE CURRENTLY RECORDED ACROSS THE REGION,  
SINGLE DIGITS WITH WIND CHILLS BELOW ZERO AS AN ARCTIC AIRMASS  
OVERSPREADS THE OHIO RIVER VALLEY. BASED ON THE 12Z PIT  
SOUNDING, 850MB TEMPS WERE MEASURED AT -23.5 CELSIUS. THIS IS 15  
DEGREES BELOW AVERAGE BASED ON CLIMATOLOGY. WITH SOUTHWEST FLOW,  
AHEAD AN APPROACHING SHORTWAVE, TEMPERATURES ARE EXPECTED TO  
INCREASE A FEW DEGREES AND RISE INTO THE LOW-TEENS IN THE NEXT 3  
TO 4 HOURS.  
 
THE AFOREMENTIONED SHORTWAVE IS EXPECTED TO CROSS INTO EASTERN  
OHIO BETWEEN 12PM AND 2PM, SNOW SHOWERS CHANCES WILL LIKELY  
RETURN TO THE REGION. SNOWFALL AMOUNTS ARE EXPECTED TO STAY  
BELOW ADVISORY CRITERIA (LIKELY 0.5 TO 1.0 INCHES IN ISOLATED  
AREAS; A TRACE TO 0.5 ELSEWHERE). BRIEF PERIODS OF LOW  
VISIBILITY FROM HEAVY SNOW CAN'T BE RULED OUT. THE 0-3KM CAPE  
VALUES RANGE FROM 25J/KG TO 50J/KG ALONG THE TROUGH AXIS AND  
COULD TURN INTO A BROKEN SNOW BAND/SNOW SQUALL. HI-RES GUIDANCE  
ALSO HAS SOME NOTED POTENTIAL STRONGER BANDS (REFLECTIVITY ON  
THE RADAR COULD MEASURE 20DBZ TO 30DBZ AT TIMES) BETWEEN 3PM TO  
6PM (INCLUDING PITTSBURGH). IF MODELS REMAIN CONSISTENT WITH  
THIS POTENTIAL OUTCOME, SHORT-FUSED SPECIAL WEATHER STATEMENTS  
AND/OR SNOW SQUALL WARNINGS MAY BE NEEDED TO HIGHLIGHT THE  
THREAT DURING THE EVENING COMMUTE.  
 
 
   
SHORT TERM /WEDNESDAY/  
 
KEY MESSAGES:  
 
- ARCTIC OUTBREAK WITH DANGEROUSLY COLD TEMPERATURE AND WIND  
CHILL CONTINUES.  
 
--------------------------------------------------------------------  
 
EXTREME COLD CONTINUES OVERNIGHT AND INTO WEDNESDAY...  
 
THE POTENTIAL FOR UPGRADING TO A EXTREME COLD WARNING ACROSS THE  
REGION REMAINS BELOW 50% FOR EARLY WEDNESDAY. THE SPREAD OF THE  
APPARENT TEMPERATURES FOR THE LATEST RUN OF THE ENSEMBLES THAT  
COVER THE 25TH TO 75TH PERCENTILE IS 6 DEGREES (BETWEEN -17F TO  
-23F). A POTENTIAL OUTCOME IS THAT A STRONG SFC HIGH BUILDS OVER  
THE REGION (POTENTIALLY AS HIGH AS 1040MB) AND MEASURED TEMPS  
COULD RANGE FROM -15F TO -18F BUT WITH VERY LITTLE WIND.  
 
HISTORICALLY, THESE ARE THE NOTED IMPACTS ACROSS OUR REGION WITH  
A COLD WEATHER OUTBREAK THIS SEVERE: 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.  
 
WE ADVISE CHECKING IN ROUTINELY WITH VULNERABLE FRIENDS AND  
FAMILY. EXTREME CARE IS ENCOURAGED FOR THE PROTECTION OF PETS  
AND ANIMALS. RESCHEDULING ANY EVENTS, ESPECIALLY THOSE TAKING  
PLACE OUTDOORS, IS ALSO ENCOURAGED.  
 
 
   
LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/  
 
KEY MESSAGES:  
 
- CONFIDENCE IS HIGH THAT VERY EXTREMELY COLD TEMPERATURES WILL  
EXIT THE REGION WEDNESDAY. HOWEVER, BELOW AVERAGE TEMPS ARE  
EXPECTED TO LINGER.  
- NEAR NORMAL TEMPS AND WIDESPREAD PRECIP MAY RETURN SUNDAY INTO  
MONDAY  
 
--------------------------------------------------------------------  
 
A RIDGE AXIS IS EXPECTED TO DRIFT OVER THE OHIO RIVER VALLEY  
EARLY WEDNESDAY. THE RETURN OF WARM SOUTHWEST FLOW WILL LIKELY END  
THE THREAT FOR EXTREME COLD CONDITIONS ACROSS PORTIONS OF THE  
REGION BY MID-DAY. OVERNIGHT LOWS/WIND CHILLS LATE WEDNESDAY  
INTO EARLY THURSDAY MAY PROMPT A COLD WEATHER ADVISORY FOR  
FORECAST ZONES WITHIN THE RIDGES (TUCKER/PRESTON), BUT THE  
POTENTIAL OF -10F WIND CHILL VALUES FOR THE LOWER TERRAIN IS  
LOW (LESS THAN 10% BASED ON NUMEROUS LONG RANGE ENSEMBLES).  
 
MODELS HAVE BEEN CONSISTENT THAT WIDESPREAD PRECIPITATION MAY  
RETURN ON SUNDAY. PROBABILITY OF MEASURABLE PRECIPITATION  
WITHIN A 24 HOUR TIME PERIOD IS 60% TO 75%, HIGHER VALUES NOTED  
ALONG THE RIDGES. IF TEMPERATURES TREND COLDER, THERE IS A 10%  
CHANCE OF SNOW AMOUNTS ALONG THE RIDGES REACH OR EXCEEDING THE  
WINTER WEATHER ADVISORY CRITERIA. IF WARM AIR LINGERS, SNOW  
RATIOS COULD TREND DOWN (DECREASING SNOW AMOUNTS TOTALS) AND A  
RAIN/SNOW/WINTRY MIX MAY OCCUR IN PORTIONS OF OUR REGION.  
 
 
   
AVIATION /15Z TUESDAY THROUGH SATURDAY/  
 
VFR CONDITIONS AND SOUTHWEST WIND UNDER 10 KNOTS WILL PREVAIL  
DURING THE MORNING HOURS AS ONE SURFACE HIGH DEPARTS. THE MAIN  
IMPACT TO AVIATION OPERATIONS WILL LIKELY BE THE BITTER COLD  
THAT HAS TAKEN HOLD ACROSS THE REGION.  
 
A SHORTWAVE TROUGH IS THEN EXPECTED TO CROSS THE REGION DURING  
THE LATE AFTERNOON/EVENING HOURS. SCATTERED SNOW SHOWERS ARE  
FORECAST TO DEVELOP AS A RESULT, BEGINNING BY 19Z OR 20Z IN  
EASTERN OHIO, AND THEN PROGRESSING EASTWARD INTO THE EVENING,  
POSSIBLY REACHING THE HIGHER ELEVATIONS BY 02Z OR SO. IT IS  
HERE WHERE HREF PROBABILITIES OF LESS THAN A MILE VISIBILITY  
ARE HIGHEST, ON THE ORDER OF 50 TO 60 PERCENT. NEVERTHELESS,  
BRIEF DROPS TO IFR VISIBILITY ARE POSSIBLE AREAWIDE IN THESE  
SNOW SHOWERS, ALONG WITH WIND GUSTS OF UP TO 25 KNOTS OR SO.  
GENERAL MVFR CEILINGS SHOULD ACCOMPANY THE SNOW.  
 
CLOUDS WILL CLEAR BEHIND THE SNOW SHOWERS LATE THIS  
EVENING/OVERNIGHT. VFR CONDITIONS, LIGHT WIND, AND EVEN MORE  
BITTERLY COLD TEMPERATURES WILL THEN TAKE HOLD THROUGH THE  
REMAINDER OF THE TAF PERIOD.  
 
OUTLOOK...  
DEVELOPMENT OF STRONG SURFACE HIGH PRESSURE FROM THE WEST WILL  
RETURN VFR (NEAR 100% PROBABILITY) TO ALL SITES BY 12Z WEDNESDAY.  
RESTRICTION AND PRECIPITATION CHANCES INCREASE FRIDAY WITH THE  
LIKELY APPROACH/PASSAGE OF THE NEXT UPPER LEVEL TROUGH.  
 
 
   
CLIMATE  
 
A PERIOD OF ANOMALOUSLY COLD WEATHER IS EXPECTED TO SETTLE IN  
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 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...COLD WEATHER ADVISORY UNTIL 1 PM EST WEDNESDAY FOR PAZ007>009-  
013>016-020>022-029-031-073-075-077.  
EXTREME COLD WARNING UNTIL 1 PM EST WEDNESDAY FOR PAZ074-076-  
078.  
OH...COLD WEATHER ADVISORY UNTIL 1 PM EST WEDNESDAY FOR OHZ039>041-  
048>050-057>059-068-069.  
WV...COLD WEATHER ADVISORY UNTIL 1 PM EST WEDNESDAY FOR WVZ001>004-  
012-021-509>511.  
EXTREME COLD WARNING UNTIL 1 PM EST WEDNESDAY FOR WVZ512>514.  
 
 
 
 
 
SYNOPSIS...HEFFERAN  
NEAR TERM...HEFFERAN  
SHORT TERM...HEFFERAN  
LONG TERM...HEFFERAN  
AVIATION...CL/AK  
CLIMATE...CM  
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