292
FXUS61 KPBZ 201806
AFDPBZ
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
106 PM EST SUN JAN 20 2019
SYNOPSIS
OLD MAN WINTER IS HERE! BITTERLY COLD TEMPERATURES TONIGHT AND
MONDAY NIGHT. WIND CHILLS WILL BE THE LOWEST TONIGHT. THE ACTIVE
WEATHER PATTERN ROLLS ON WITH THE NEXT SYSTEM MIDWEEK. THERE COULD
BE A WINTRY MIX WEDNESDAY MORNING FOR PARTS OF THE AREA. A BRIEF
WARM UP TO ABOVE NORMAL TEMPERATURES WEDNESDAY, BEFORE A RETURN OF
ARCTIC AIR FOR LATE WEEK.
NEAR TERM /THROUGH MONDAY/
WILL LET HEADLINES EXPIRE FOR THE MOUNTAINS AS THE WORSE OF THE
WEATHER IS OVER. LAKE ENHANCED BANDS WILL CONTINUE TO GENERATE
SCATTERED SNOW SHOWERS THE REST OF THE DAY GIVEN DELTA TS. NAM3KM
DOES A GOOD JOB ILLUSTRATING IT AS IT PIVOTS THROUGH UNTIL 6Z. WOULD
NOT BE SURPRISED TO SEE 1-2" OF FLUFFY SNOW BE REPORTED WITH THIS
BAND AS DGZ IS AT THE GROUND OFFSETTING HIGHER SNOWFALL.
FLURRIES WON'T LEAVE THE MOUNTAINS UNTIL RIDGING IS RIGHT ON TOP OF
US, SO WILL CARRY FLURRY MENTION FOR MOST OF THE DAY MONDAY, BUT NO
ACCUMULATION. COLD WILL BE THE MAIN WEATHER HEADLINE MLK DAY WITH
H8 TEMPS AROUND -20C. DESPITE WEAK WARM ADVECTION AT THIS LEVEL, DO
NOT SEE TEMPS MAKING IT OUT OF THE MIDDLE TEENS EVEN FOR SOUTHERN
AREAS, WHILE UP NORTH UPPER SINGLE DIGITS ARE LIKELY. WIND CHILL
VALUES WILL BOTTOM OUT IN THE -10 TO -25 RANGE AND SLOWLY WORK THEIR
WAY UP TO THE NEGATIVE SINGLE DIGITS MONDAY AFTERNOON.
WIND CHILL HEADLINES REMAIN UNCHANGED.
SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY NIGHT/
WE START OUT WITH THE COLDEST NIGHT OF THE SEASON TEMPERATURE WISE.
ALL THINGS COMING TOGETHER FOR A WIDE SPREAD OF SUB ZERO TEMPS TO
MIDDLE SINGLE DIGIT VALUES; CLEAR NIGHT, CALM WIND, AND SNOW PACK.
SOME OF THE DEEPER HOLLOWS / VALLEYS MAY PUSH -10F BY DAYBREAK
TUESDAY. WIND CHILL VALUES WILL BE RIGHT AROUND THE AMBIENT AIR
TEMPERATURE GIVEN FORECAST WIND SPEED.
ARCTIC AIR AS USUAL IS VERY SHALLOW AND STRONG WARM ADVECTION ON THE
BACKSIDE OF THE ANTICYCLONE WILL GIVE BIG BOOSTS TO OUR TEMPERATURES
TUESDAY AND WEDNESDAY. BY WEDNESDAY, AFTERNOON HIGHS WILL BE NEARLY
40 DEGREES WARMER THAN AT DAWN MLK DAY. THE ONLY CONUNDRUM WITH
THIS IS WE HAVE OUR NEXT WEATHER SYSTEM FAST APPROACHING FROM THE
SOUTH. PTYPE WILL BE A CONCERN AT THE ONSET, ESPECIALLY ACROSS
NORTHWEST PA AND THE MOUNTAINS WHERE SEVERAL DAYS OF SUB 32F WEATHER
WILL MAKE THE GROUND COLD, SO FREEZING RAIN COULD BE OBSERVED AT THE
ONSET DESPITE HAVING SURFACE TEMPERATURES ABOVE FREEZING. THE
STRENGTH OF THE WARM LAYER ALOFT STILL BRINGS INTO QUESTION MORE
THAN ONE PTYPE. WOULD NOT BE SURPRISED IF IT STARTS OUT AS SNOW
THEN A WINTRY MIX TO RAIN BY AFTERNOON. WINTER WEATHER ADVISORIES
MAY BE NEEDED FOR THIS PERIOD. ALL AREAS WILL SWITCH TO RAIN AS
SOUTHERLY WINDS BRING THE ENTIRE COLUMN ABOVE FREEZING AS WE MOVE
INTO THE WARM SECTOR DURING THE AFTERNOON. THE ASSOCIATED COLD
FRONT MOVES DURING THE NIGHT AND WILL SPREAD WIDESPREAD RAIN TO THE
REGION. BOUNDARY LAYER TEMPERATURES COLLAPSE WITH THE NEXT SHOT OF
COLD AIR BEHIND IT, SO SNOW IS LIKELY BEFORE EVERYTHING WINDS DOWN.
ACCUMULATIONS AT THIS JUNCTURE WILL BE LIGHT.
LONG TERM /THURSDAY THROUGH SUNDAY/
HIGHLIGHTS:
- STRONG FRONT FRIDAY
- WEEKEND ARCTIC BLAST
- BELOW NORMAL TEMPERATURES
POST FRONTAL SNOW SHOWERS THURSDAY WON'T BE THAT BAD GIVEN FLOW IS
WESTERLY AND TRAJECTORY OF LOW PRESSURE SYSTEM. THERE IS A BETTER
CHANCE THURSDAY NIGHT AS THE ASSOCIATED UPPER AIR SHORTWAVE TROUGH
PASSES.
LONG RANGE MODELS CONTINUE TO STRESS A POTENT FRONT CROSSING FRIDAY.
IT COULD BE ONE THAT GENERATES SNOW SQUALL WARNINGS PER AMOUNT OF
LOW LEVEL INSTABILITY AND TEMPERATURE GRADIENT ASSOCIATED WITH IT.
STILL TO EARLY NOW FOR THE HWO MENTION, BUT DEFINITELY SOMETHING TO
KEEP AN EYE AS THE WEEK GOES BY. IN WAKE OF THE BAROCLINIC ZONE,
BELOW NORMAL TEMPERATURES AS H8 TEMPS BOTTOM OUT AGAIN IN THE -20C
RANGE. THIS WOULD EQUATE TO HIGHS / LOWS SOMEWHAT SIMILAR TO WHAT
WE WILL SEE ON MLK DAY, PERHAPS A LITTLE WARMER. WIND CHILLS COULD
BE A CONCERN ON FRIDAY AS WELL.
THE UPCOMING WEEKEND LOOKS COLD AND CLOUDY WITH SCATTERED SNOW
SHOWERS, BUT NO SIGNIFICANT ACCUMULATION.
AVIATION /18Z SUNDAY THROUGH FRIDAY/
NORTHWEST FLOW OFF OF LAKE ERIE WILL KEEP MVFR CEILINGS INTO
THIS EVENING ACROSS MANY TERMINALS, THERE ARE ENOUGH BREAKS IN
THE CLOUDS TO SUPPORT VFR CONDITIONS AT TIMES. BANDED SNOW
SHOWERS WILL SUPPORT SHORT-TERM VISIBILITY RESTRICTIONS TO IFR
AT LEAST BRIEFLY, AND WIND GUSTING TO BETWEEN 20 AND 30 KNOTS
WILL ALSO CONTINUE TO CREATE BLOWING SNOW CONCERNS, ESPECIALLY
NORTH OF PIT.
WINDS WILL CONTINUE TO GUST TONIGHT, WITH CONTINUED OCCASIONAL
MVFR CIG/VIS IN ISOLATED/SCATTERED SNOW SHOWERS. THESE WILL
BREAK UP MONDAY MORNING, WITH VFR CONDITIONS POTENTIALLY
AREAWIDE BY THE AFTERNOON.
CEILINGS WILL REMAIN MOSTLY IFR WITH INTERMITTENT MVFR ACROSS
ALL SITES OVERNIGHT SAVE FOR DUJ AND FKL WHERE HEAVIER SNOW IS
EXPECTED TO DROP VISIBILITIES TO LIFR. SNOW WILL EXIT THE AREA
SUNDAY MORNING FROM WEST TO EAST AFTER SUNRISE, WITH A RETURN TO
MVFR/VFR AT MOST SITES DURING THE AFTERNOON. WIND WILL ALSO
BEGIN TO RELAX TOMORROW AS THE PRESSURE GRADIENT DECREASES.
OUTLOOK
RESTRICTIONS ARE LIKELY AGAIN WITH A TUE NIGHT/WED COLD FRONT.
PBZ WATCHES/WARNINGS/ADVISORIES
MD...WIND CHILL WARNING FROM 7 PM THIS EVENING TO 1 PM EST MONDAY
FOR MDZ001.
OH...WIND CHILL ADVISORY FROM 7 PM THIS EVENING TO 1 PM EST MONDAY
FOR OHZ039>041-048>050-057>059-068-069.
PA...WIND CHILL ADVISORY FROM 7 PM THIS EVENING TO 1 PM EST MONDAY
FOR PAZ007>009-013>016-020>023-029-031-073-075.
WIND CHILL WARNING FROM 7 PM THIS EVENING TO 1 PM EST MONDAY
FOR PAZ074-076.
WV...WIND CHILL ADVISORY FROM 7 PM THIS EVENING TO 1 PM EST MONDAY
FOR WVZ001>004-012-021-509-510.
WIND CHILL WARNING FROM 7 PM THIS EVENING TO 1 PM EST MONDAY
FOR WVZ511>514.
98/CL
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page