538
FXUS61 KCTP 070840
AFDCTP
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
340 AM EST WED JAN 7 2026
WHAT HAS CHANGED
NOTHING.
KEY MESSAGES
1) BLUSTERY. LIGHT RAIN/DRIZZLE IN THE LAURELS AND A MIX OF
SNOW AND RAIN OVER THE NORTHWEST WILL TAPER OFF THROUGH THE DAY.
2) DENSE FOG IS POSSIBLE IN THE EAST UNTIL THE WIND KICKS UP
EARLY TODAY.
3) JANUARY THAW RAMPS THROUGH LATE WEEK WITH ABOVE NORMAL
TEMPERATURES AND PERIODS OF RAIN FRIDAY INTO SATURDAY;
4) MONITORING RIVER RISES FROM RAIN + SNOWMELT FOR ICE JAMS
5) TURNING WINDY AND SEASONABLY COLDER SUNDAY WITH SNOW SHOWERS
DOWNWIND OF LAKE ERIE
DISCUSSION
KEY MESSAGE 1...
UPSLOPE IN WESTERLY LLVL FLOW WILL KEEP SOME SHOWERS OF RAIN
GOING IN THE LAURELS AND RAIN/SNOW SHOWERS OVER THE NW. THE
TEMPS ARE GOING TO BE A LITTLE TOO WARM (32-35F) IN THE NW TO
ALLOW MUCH MORE THAN A LITTLE SLUSH TO BRIEFLY COAT THE GROUND
THIS MORNING. IT WILL LIKELY MELT AS IT FALLS, THOUGH. WESTERLY
WIND BEHIND THE COLD FRONT MOVING THROUGH THIS MORNING WILL
INCREASE BRIEFLY, BUT LOWER A LITTLE AS HIGH PRESSURE BUILDS IN
FROM THE WEST AND THE GRADIENT RELAXES.
KEY MESSAGE 2...
FOG IS GOING TO HAVE A SHORT LIFE OVER THE EASTERN ZONES FOR THE
NEXT 6-8 HRS. BUT, THE NULL FLOW OR EVEN A LIGHT UPSLOPE LIKE
THERE IS AT ZERBY AIRPORT (SCHUYLKILL CO) WILL ALLOW FOR THE
MOIST GROUND TO CONTRIBUTE NEGATIVELY TO THE VISIBILITIES THIS
MORNING. AS THE FRONT PASSES AND MIXES THINGS UP/DEEPENS THE
MIXED LAYER, THE FOG WILL GET BLOWN AWAY, OR SUCCUMB TO THE
RISING TEMPS. DON'T EXPECT MUCH FOG PAST 10-12Z DEPENDING ON
JUST HOW QUICKLY THE AIR ALOFT CAN MIX DOWN. WE'LL MONITOR FOR A
POSSIBLE DENSE FOG ADVY, BUT AT THIS POINT, THE VSBY IS ONLY
BAD AT ISOLATED LOCATIONS.
KEY MESSAGE 3...
THE HIGH PRESSURE FROM TX SLIDES NE THRU THE NEXT COUPLE OF
DAYS, SETTING UP A GOOD GULF CONNECTION. 8H TEMPS RISE INTO THE
UPPER SINGLE DIGITS OR EVEN +10C (SW) BY FRIDAY. SFC WARM FRONT
SHOULD MOVE THROUGH ON FRIDAY, BUT THE SFC LOW WILL BE WELL INTO
NRN ONT BY THEN. THE (FIRST) COLD FRONT MAY NOT CLEAR THE STATE
AS IT HANGS UP, LAYING OUT W-E. ANOTHER LOW WILL FORM ON THE
DEEP MOISTURE FEED FROM THE GULF, SLIDING JUST WEST OF THE CWA.
A RUMBLE OF THUNDER ISN'T OUT OF THE QUESTION SAT AS SOME OF THE
AREA MAY GET INTO THE WARM SECTOR. BUT, SAT'S A LITTLE FAR AWAY
TO TRUST DETAILS LIKE THAT.
KEY MESSAGE 4...
AS THE TEMPS WARM AND RAIN FALLS FINISHING OFF ANY REMAINING
SNOWPACK, SOME OF THE WATER WILL MAKE IT'S WAY INTO THE
WATERWAYS. ICE HAS FORMED OVER THE PAST COUPLE OF WEEKS. BUT,
THE WARM UP BEFORE THE RAIN ARRIVES SHOULD HELP THE ICE SOFTEN
OR MELT AWAY. STILL, A COUPLE OF WATERWAYS COULD SEE AN ICE JAM
OR TWO. ICE JAMS ARE A VERY RANDOM THING AND ALL WE CAN HOPE TO
DO IS RECOGNIZE THAT THIS IS THE TIME AND PATTERN TO HAVE THEM
HAPPEN. THE HEAVIER THE RUNOFF, THE MORE WIDESPREAD THE THREAT
WOULD BE AS THE ICE WOULD BE BROKEN UP FASTER AND MOVED MORE
EASILY. A JAM BELOW MARIETTA (ABOVE SAFE HARBOR DAM) ON THE
SUSQ HAS CAUSED THE WATER TO RISE THERE. BUT, THE RIVER IS WELL BELOW
FLOOD STAGE AND INCHING DOWNWARD AS THE ICE MELT AND SLIDE
DOWN-RIVER. AGAIN, JUST SOMETHING TO KEEP IN MIND AT THIS POINT.
ICE EFFECTS ARE SEEN AT MANY SITES. THERE IS ALWAYS A DISCUSSION
ON HOW TO FORECAST THE RIVER STAGES WHEN THE VOLUME OF WATER
FLOW (AT MARIETTA CURRENTLY = 17KCFS/35FT) IS LITERALLY 4X LESS
THAN WHAT THE RIVER STAGE SHOWS (LOOKS LIKE 76KCFS/40FT) DUE TO
THE ICE EFFECTS. IN ADDITION, DIFFERENT TYPES OF RIVER GAUGES
WORK IN DIFFERENT WAYS AND WILL BE AFFECTED DIFFERENTLY BY THE
PRESENCE OF ICE. AS ALWAYS, THE BEST COURSE OF ACTION IF YOU
LIVE ALONG THE RIVER IS TO WATCH THE PROGRESS OF THE ICE AND
WHERE THE WATER ACTUALLY IS ON THE BANKS INSTEAD OF WHAT THE
ACTUAL FLOW WOULD NORMALLY HAVE THE STAGE READ.
KEY MESSAGE 5...
THE LOW PRESSURE AREA LIFTING AWAY FROM US ON SUNDAY WILL
CONTINUE TO DEEPEN AS IT GETS INTO ONT AND QUE. THE COLD FRONT
SHOULD BE OFF THE COAST BEFORE SUNRISE SUNDAY. THE LOW WILL
THUS BE PULLING IN COLD AIR RAPIDLY FROM THE HIGH PRESSURE DOME
TO OUR NW (COMING FROM THE CANADIAN PLAINS) AND DROP THE
1000-500HPA THICKNESS DOWN TO AROUND 510DAM. A TRULY ARCTIC
AIRMASS WILL SLIDE OVER THE EASTERN US, TURNING THE WIND TO THE
NW AND CRANKING UP THE LAKE EFFECT SNOW MACHINE. 0C 8H TEMPS
MAKE IT TO THE FL PANHANDLE. OUR LOFTY 8H TEMPS OF +10C FRIDAY
WILL FALL VERY QUICKLY TO THAT MUCH OR MORE BELOW ZERO ON
SUNDAY, SHOCKING THE SENSES. THE WIND WILL BE GUSTY AS THE
GRADIENT WILL BE TIGHT AND VERTICAL FLOW WELL-ALIGNED. GUSTS
INTO THE 40S MAY BE ON TAP FOR THE HIGHER ELEVATIONS. IT WON'T
LAST ALL THAT LONG AS THE HIGH PRESSURE MOVES TO THE EAST. THAT
SHOULD DIRECT MILDER AIR BACK IN DURING THE FIRST HALF OF THE
NEW WEEK.
MAXES WILL FALL 10-20F FROM SAT TO SUN (MOST DRASTICALLY IN THE
NW - WARREN/MCKEAN COS). THE COLDEST AIR WILL BE OVERHEAD SUN
NIGHT/MON. MONDAYS TEMPS WILL BE COLDEST, BUT NOT FAR OFF
NORMALS. TEMPS GO RIGHT BACK ABOVE NORMALS TUES ON THE SRLY
FLOW.
AVIATION /07Z WEDNESDAY THROUGH SUNDAY/
06Z TAFS SENT.
NOT MUCH ON THE RADAR, ABOUT 2 BANDS OF SHOWERS TO THE NORTH
AND WEST OF THE OFFICE HERE.
A WIDE RANGE OF CONDITIONS OVERNIGHT. LIGHT WINDS ACROSS MUCH OF
THE AREA WITH COLD AIR NEAR THE GROUND, WHILE FURTHER WEST A
GUSTY WIND ACROSS THE HIGHER ELEVATIONS AT SITES LIKE JST.
OVERALL I DID NOT CHANGE A LOT, MAINLY LATER TODAY TO TRY TO
ACCOUNT FOR SOME IMPROVEMENT.
ALSO TOOK OUT MENTION OF SNOW OVERNIGHT ACROSS THE WEST, AS
THE COLD AIR COMING IN LATER IS NOT THAT COLD.
EARLIER DISCUSSION BELOW.
SO FAR TONIGHT, CEILINGS HAVE BEEN STAYING HIGHER THAN EXPECTED
WITH MVFR EVERYWHERE EXCEPT BFD. SCATTERED LIGHT RAIN SHOWERS
WILL CONTINUE OVERNIGHT WITH AT-WORST MVFR VISIBILITIES
EXPECTED. COLDER AIR WORKING INTO NORTHWEST PA SHOULD ALLOW
FOR SNOW TO MIX IN WITH THE RAIN AT BFD AFTER 06Z. THE FORECAST
IS MOST TENUOUS IN SOUTHEAST PA WHERE SKIES COULD SCATTER/CLEAR
OUT RESULTING IN ANYTHING RANGING FROM VFR CONDITIONS TO LIFR
IF LOCALLY DENSE FOG DEVELOPS. THERE IS A 50-50% CHANCE THAT
MDT AND LNS SEE A PERIOD OF VISIBILITY BELOW 1 MILE BEFORE WINDS
PICK UP IN THE EARLY MORNING.
A 40 TO 50 KNOT LOW-LEVEL JET MOVED IN EARLIER THIS EVENING,
LEADING TO A PERIOD OF LLWS AT BFD, JST, AOO, AND UNV. SURFACE
WIND GUSTS WILL GRADUALLY INCREASE AS WELL, WITH GUSTS OF 20 TO
25 KNOTS POSSIBLE BY SUNRISE. CEILINGS SLOWLY RISE THROUGH THE
MORNING, BUT -SHRA/DZ/FZDZ WILL CONTINUE INTO THE EARLY
AFTERNOON AT BFD AND JST.
OUTLOOK...
THU...MAINLY VFR.
FRI-SAT...RESTRICTIONS WITH A BATCH OF STEADY RAIN AND COLD
FRONT SAT NIGHT.
SUN...SNOW SHOWERS POSSIBLE MAINLY WEST OF UNV.
CTP WATCHES/WARNINGS/ADVISORIES
NONE.
WHAT HAS CHANGED...DANGELO
KEY MESSAGES...DANGELO/STEINBUGL/COLBERT
DISCUSSION...DANGELO/STEINBUGL/COLBERT
AVIATION...BANGHOFF/MARTIN/BAUCO
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