102
FXUS61 KCTP 061103
AFDCTP
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
703 AM EDT SAT JUN 6 2026
WHAT HAS CHANGED
* INCREASING CONFIDENCE IN SEVERE WEATHER THIS AFTERNOON AND
EVENING
* WPC HAS INCLUDED THE LAUREL HIGHLANDS IN A SLIGHT RISK FOR
EXCESSIVE RAINFALL
KEY MESSAGES
1) SEVERE WEATHER IS INCREASINGLY LIKELY THIS AFTERNOON AND
EVENING.
2) WARMTH SURGES AGAIN NEXT WEEK WITH A CLASSIC SUMMERLIKE
PATTERN EXPECTED - THOUGH UNCERTAINTY REMAINS.
DISCUSSION
KEY MESSAGE 1: SEVERE WEATHER IS INCREASINGLY LIKELY THIS
AFTERNOON AND EVENING.
AN UPPER SHORTWAVE TROUGH DIVING OUT OF THE GREAT LAKES REGION WILL
BRING AN INCREASING CHANCE FOR SHOWERS/T-STORMS THIS AFTERNOON
AND EVENING. SPC MAINTAINS A LEVEL 2/5 (SLGT) SEVERE T-STORM
RISK, WHICH INCLUDES ALL OF CENTRAL PA. OF NOTE, THE WIND
PROBABILITIES ARE 30 PERCENT SOUTH OF ROUTE 6 (HIGHER THAN THE
15 PERCENT PROBABILITIES THAT WE SEE WITH MOST SLIGHT RISKS).
LATEST HIRES GUIDANCE CONTINUES TO SHOW SPREAD WITH RESPECT TO
THE NUMBER AND TIMING OF CONVECTIVE ELEMENTS THROUGH THE DAY
SATURDAY. RADAR TRENDS DO SHOW MORNING RAIN SHOWERS UPSTREAM OF
OUR NW ZONES, BUT ANYTHING BEFORE 1 PM WILL LIKELY BE
NONSEVERE.
THE HIGHEST CHANCE FOR SEVERE WEATHER WILL BE IN THE LATE
AFTERNOON AND EVENING HOURS, SPARKED BY A BOOST OF LARGER SCALE
ASCENT LINKED TO THE THERMALLY DIRECT, RIGHT ENTRANCE REGION OF
A ROBUST MID AND UPPER LEVEL JET SEGMENT AS WELL AS POSITIVE
VORTICITY ADVECTION ALOFT. SBCAPE CLIMBS TO NEAR 1500 J/KG
THIS AFTERNOON AND EARLY EVENING WITH SFC-6 KM SHEAR OF 30-40
KTS. THE PRIMARY TRIGGERING MECHANISM FOR CONVECTION INITIATION WILL
LIKELY BE A PREFRONTAL SFC TROUGH SET UP JUST INLAND FROM LAKE
ERIE, AS WELL AS ANY COLD POOLS FROM PREEXISTING CONVECTION
MOVING IN FROM THE WEST. HODOGRAPHS ARE PRIMARILY STRAIGHT (WEST
TO EAST) AND MAY SUPPORT SPLITTING SUPERCELLS EARLY ON, BUT AS
COLD POOLS GROW/MERGE WE ANTICIPATE UPSCALE GROWTH INTO LINE
SEGMENTS WITH PREFERRED STORM MOTION TOWARDS THE SOUTHEAST.
DAMAGING WINDS AND LARGE HAIL WILL BE THE PRIMARY SEVERE
HAZARDS, BUT A TORNADO CAN NOT BE RULED OUT PARTICULARLY IN
WESTERN ZONES WHERE THERE IS A LITTLE MORE TURNING IN THE LOW
LEVELS OF THE ATMOSPHERE. LARGE HAIL WOULD ALSO BE FAVORED MORE
IN THE WESTERN ZONES, ESPECIALLY IN ANY SUPERCELLS THAT MAY
DEVELOP PRIOR TO LINEAR MODES. IN TERMS OF WIND, SEVERAL OF THE
HRRR RUNS OVER THE PAST 24 HOURS HAVE SHOWN FAIRLY LARGE BOW
ECHOS DEVELOPING WITH WIND GUSTS OF 50-65 MPH EMBEDDED WITHIN
THEM, BUT THERE ARE CONSIDERABLE RUN TO RUN DIFFERENCES IN THE
TRACK OF THESE CONVECTIVE ELEMENTS.
MODEL GUIDANCE REMAINS GENERALLY DRY ON SUNDAY, WITH MUCH OF
THE PRECIP ENDING AROUND MIDNIGHT TONIGHT. RAINFALL TOTALS ARE
EXPECTED TO BE HIGHEST IN THE WEST AND SOUTHWEST (UP TO 1 INCH),
WITH STORMS PRODUCING LESS RAINFALL OVER THE SOUTHEAST AS THE
EVENING WEARS ON AND DAYTIME HEATING IS LOST. THIS PATTERN DOES
NOT BODE WELL FOR ONGOING DROUGHT CONDITIONS. THERE IS A WPC
SLGT ERO IN THE LAURELS, BUT DRY ANTECEDENT CONDITIONS WILL
LIKELY OFFSET THE FLOOD POTENTIAL.
PATCHY FOG WILL BE POSSIBLE LATE TONIGHT INTO SUNDAY MORNING AS
CLOUDS CLEAR OUT BEHIND THE COLD FRONT AND THE WET GROUND
ALLOWS FOR SFC RH NEAR 100 PCT IN SPOTS. KEY LIMITING FACTOR
WILL BE HOW QUICKLY THE WINDS DIMINISH AS SKIES CLEAR OUT.
--------------------------------------------------------
KEY MESSAGE 2: WARMTH SURGES AGAIN NEXT WEEK WITH A CLASSIC
SUMMERLIKE PATTERN EXPECTED - THOUGH UNCERTAINTY REMAINS.
FOLLOWING A MODEST COOL DOWN ON MONDAY, EMERGING MODEL DATA
CONTINUES TO SIGNAL ABOVE NORMAL TEMPERATURES FOR THE REST OF
NEXT WEEK. EVEN THE COOL DOWN ON MONDAY WILL SEE ABOVE NORMAL
HIGH TEMPERATURES FOR MOST OF THE AREA. LONG RANGE MODELS
DIVERGE ON POTENTIAL SOLUTIONS TOWARD THE END OF NEXT WEEK. A
PREVAILING RIDGE IN PLACE OVER THE EASTERN US WILL ENSURE ABOVE
NORMAL TEMPERATURES (80S AND 90S), BUT MODELS DIVERGE IN HOW
THEY HANDLE AN UPPER CLOSED LOW MOVING OUT OF THE SOUTH CENTRAL
US UP TOWARDS THE GREAT LAKES. LATEST NBM HAS 20-40 PCT POPS
COVERING AT LEAST A PORTION OF CENTRAL PA EACH DAY TUESDAY
THROUGH THE END OF THE COMING WEEK, BUT REALISTICALLY MUCH OF
THAT TIME PERIOD MAY END UP DRY IF THE UNSETTLED WEATHER WITH
THE AFOREMENTIONED UPPER DISTURBANCE PASSES TO OUR WEST.
AVIATION /12Z SATURDAY THROUGH WEDNESDAY/
SOME SHOWERS ACROSS NW PA WILL CONTINUE OVER THE NEXT COUPLE OF
HOURS WITH MVFR CEILINGS INCREASINGLY LIKELY AT BFD AFTER 15Z
SATURDAY BASED ON A NBM/HREF/GLAMP BLEND. LARGER PERIOD OF
CONCERN FOR AVIATION PURPOSES ACROSS CENTRAL PENNSYLVANIA
REMAINS AFTER 18Z SATURDAY THROUGH 12Z SUNDAY WITH SEVERE
THUNDERSTORM POTENTIAL (DAMAGING WINDS/LARGE HAIL MAIN CONCERNS)
AND POTENTIAL FOR FOG FORMATION OVERNIGHT INTO SUNDAY MORNING.
RECENT GUIDANCE CONTINUES TO DEVELOP TSRA IN VERY CLOSE
PROXIMITY TO BFD IN THE ~19Z-21Z SATURDAY TIMEFRAME. GIVEN AMPLE
DESTABILIZATION AND SHEAR, EXPECT TSRA TO LARGELY GROW UPSCALE
AND IMPACT MUCH OF THE AREA AS THIS COMPLEX SHIFTS MAINLY
SOUTHEASTERLY ACROSS THE FORECAST AREA. THE 12Z TAF PACKAGE HAS
MORE ROBUST MENTIONS FOR TSRA, WITH TEMPOS AT JST/AOO WHERE
CONFIDENCE REMAINS HIGHEST FOR TSRA. THE 00Z HREF DID OUTLINE
HIGHER PROBABILITIES AT BFD/UNV/IPT; HOWEVER, LOWER CONFIDENCE
IN TIMING/INITIATION WARRANTS A CONTINUATION IN PROB30S. IN
TSRA, DAMAGING WINDS WILL BE THE MAIN HAZARD BUT LOW CONFIDENCE
AT THIS TIME HORIZON KEEPS SEVERE WIND GUSTS OUT OF THE TAFS AT
THIS POINT. AFTER 00Z SUNDAY, MENTIONS FOR SHRA/TSRA DECREASE
ACROSS MUCH OF THE AREA; HOWEVER, CLEARING SKIES WILL ALLOW FOR
FOG FORMATION AND RESTRICTIONS POSSIBLE BETWEEN 00-12Z SUNDAY
ACROSS MAINLY THE WESTERN TERMINALS. CURRENT HREF OUTLINES
HIGHEST PROBABILITIES FOR IFR/LIFR CONDITIONS AT BFD/JST;
HOWEVER, REASONABLE WORST-CASE SCENARIO EXTENDS THESE MENTIONS
TO AOO/UNV/IPT FOR LOWER CEILINGS AND MDT/LNS FOR LOWER
VISIBILITIES BUT LOWER CONFIDENCE KEEPS MENTIONS OUT OF THE 12Z
TAF PACKAGE.
OUTLOOK...
SUN-TUE...VFR FAVORED OUTSIDE OF ISOLATED MORNING FOG.
RESTRICTIONS POSSIBLE IN -SHRA/-TSRA EARLY SUN & AGAIN LATE
TUE.
WED...RESTRICTIONS POSSIBLE IN -SHRA/-TSRA.
CTP WATCHES/WARNINGS/ADVISORIES
NONE.
WHAT HAS CHANGED...COLBERT
KEY MESSAGES...LAMBERT/COLBERT
DISCUSSION...LAMBERT/COLBERT
AVIATION...BEATY
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page