176
FXUS61 KCTP 020600
AFDCTP
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
200 AM EDT TUE SEP 2 2025
SYNOPSIS
* DRY WEATHER IS EXPECTED TO CONTINUE THROUGH THE MIDDLE OF THIS
WEEK, FEATURING COOL NIGHTS, AND WARM COMFORTABLE AFTERNOONS
* AURORA BOREALIS MAY BE VISIBLE TONIGHT; GEOMAGNETIC STORM
WATCH IN EFFECT
* NEXT WIDESPREAD CHANCE FOR SHOWERS COMES THURSDAY WITH A COLD
FRONT. SCATTERED SHOWERS POSSIBLE WED IN FAR WESTERN PA
* MORE SHOWERS AND STORMS POSSIBLE ON SATURDAY WITH STRONG COLD
FRONT
NEAR TERM /THROUGH TODAY/
THE UPPER LEVEL REX BLOCK OVER SE CANADA AND THE NE U.S. THIS
MORNING WILL CONTINUE TO BREAK DOWN INTO A GRADUALLY NORTHWARD
LIFTING, RELATIVELY WEAK UPPER LOW FOR TONIGHT THROUGH TUESDAY
AS A RESULT OF POTENT UPPER LEVEL ENERGY DIGGING SE FROM
CENTRAL CANADA.
AT THE SURFACE, HIGH PRESSURE STRETCHES FROM THE GREAT LAKES TO
THE ST LAWRENCE VALLEY, CREATING A LIGHT EAST TO SE FLOW ACROSS
THE CWA THIS EVENING THROUGH THE OVERNIGHT.
VALLEY FOG IS NOT AS LIKELY TONIGHT AS IN MANY PREVIOUS MORNINGS,
MAINLY DUE TO SOME CLOUDS AND ANOTHER DAY TO DRY OUT. LOWS WILL
COOL OFF TO A FEW DEGREES BELOW NORMAL.
PATCHY FOG IS PAINTED IN THE VALLEYS OF NORTHERN PA LATE TONIGHT
THROUGH ABOUT 12-13Z TUESDAY.
FOR TUESDAY, SIMILAR WEATHER AND TEMPERATURES WILL PREVAIL, AS
HIGH PRESSURE REMAINS ACROSS THE AREA. WINDS WILL REMAIN ON THE
LIGHT SIDE.
SHORT TERM /TONIGHT THROUGH 6 PM WEDNESDAY/
TUESDAY NIGHT INTO WED MORNING, LIGHT SE TO SOUTHERLY SFC FLOW
WILL BE TOPPED BY THE PASSAGE OF A SMALL SCALE BUT DEEP RIDGE
AXIS (AND DRY AIR) AT AND ABOVE THE 850 MB LEVEL. PWAT VALUES
WILL AVERAGE BETWEEN 0.5-0.75 ACROSS THE REGION PER THE LATEST
HREF AND ONLY PATCHY, SHALLOW STRATO CU WILL BE PRESENT.
ANOMALOUSLY LOW PWAT VALUES AND SHALLOW, SCT-BKN LOW CLOUDS WILL
BE FOUND THROUGH MUCH OF WEDNESDAY ACROSS ALL BUT THE FAR
WESTERN PART OF THE CWA (LATER IN THE DAY).
MAX TEMPS WED WILL BE 2-4 DEG F HIGHER THAN TUESDAY, AND WITHIN
A DEG F OR TWO OF NORMAL.
LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/
A DEEP UPPER LEVEL LOW WILL RESULT IN SOME SHOWERS AND PERHAPS
A STORM ON THURSDAY, AS THE COLD FRONT MOVES INTO CENTRAL PA
BY LATE THURSDAY.
THE UPPER LEVEL SUPPORT WILL BE LIFTING NORTHEAST OF THE AREA,
SO THE CHANCE OF STRONG STORMS AND HEAVY RAIN LIMITED. AS WAS
THE CASE LAST THURSDAY EVENING, THE HIGHEST CHANCE OF SUCH
ACTIVITY WILL BE OVER LAKE ERIE, WHERE THE WARM WATERS CAN ADD
MOISTURE.
THE NEXT COLD FRONT MOVES INTO THE AREA LATE FRIDAY NIGHT -
SATURDAY, FOLLOWED BY BELOW NORMAL TEMPERATURES. DYNAMICS COULD
SUPPORT STRONG STORMS, BUT NOT UNDER ANY OUTLOOKS AT THIS POINT.
SIMILAR TO YESTERDAY (SUNDAY) AT THIS TIME, GFS'S TIMING OF THE
CFROPA IS STILL 6+ HOURS FASTER THAN THE EC (AND DURING THE
LATE NIGHT/EARLY MORNING HOURS SATURDAY) PLACING MUCH OF THE CWA
UNDER A PRONOUNCED DRY SLOT AND A PRECIP MIN FOR MOST OR ALL OF
THE DAYLIGHT HOURS OF SATURDAY. 01/23Z NBE GUIDANCE INDICATES
ONLY 25-30 POPS FOR THE 12Z SAT- 00Z SUNDAY PERIOD (SPLITTING
THE DIFF OF THE OPERATIONAL GFS AND EC).
MODELS NOT IN THE BEST AGREEMENT ON THE DETAILS AS ONE GETS
OUT TO DAY 10, BUT LITTLE SIGNAL FOR ANY EXTENDED WARM SPELLS.
FLOW FOR LATE FRIDAY INTO SATURDAY A BIT TOO MUCH WEST TO
SOUTHWEST FOR MUCH LATE EFFECT, BUT DID ADJUST POPS A BIT
HIGHER FOR A FEW SMALL AREAS ACROSS THE NW.
AVIATION /06Z TUESDAY THROUGH SATURDAY/
SCATTERED CLOUDS BETWEEN 6000 AND 10000 FEET WILL CONTINUE TO
DRIFT ACROSS PORTIONS OF CENTRAL PA THROUGH THE REST OF THE
NIGHT. SOME PATCHY VALLEY FOG MAY FORM, BUT ALL GUIDANCE
SUGGESTS THAT IT WILL STAY AWAY FROM ANY AIRFIELDS AND VFR
CONDITIONS ARE EXPECTED THROUGH THE 06Z TAF PERIOD. FAIR
WEATHER CUMULUS CLOUDS ARE EXPECTED TO FORM ONCE AGAIN DURING
THE AFTERNOON AND MAY BE MORE WIDESPREAD THAN THEY WERE ON
MONDAY. THERE IS ALSO THE POTENTIAL FOR ISOLATED SHOWERS TO
DEVELOP, BUT WITH COVERAGE EXPECTED TO BE VERY LOW, WE WILL KEEP
ANY MENTIONS OF RAIN OUT OF THE TAFS. THE BEST CHANCE FOR A
SHOWER OR TWO (~20%) WILL BE NEAR JST, AOO, AND UNV. THE CHANCE
FOR SHOWERS WILL COME TO AN END AFTER SUNSET AND CLOUD COVER
WILL GRADUALLY DECREASE.
OUTLOOK...
WED...MAINLY VFR. ISOLATED SHRA POSSIBLE IN THE LATE AFTERNOON
MAINLY SOUTH AND WEST OF JST.
THU...WIDESPREAD SHRA EXPECTED WITH TSRA POSSIBLE.
FRI...SHOWERS LINGERING, MAINLY ACROSS THE EAST.
SAT...CHANCE OF SHRA WITH TSRA POSSIBLE.
CLIMATE
A RECORD LOW TEMPERATURE OF 39 DEGREES WAS SET AT ALTOONA
YESTERDAY, AUG 31. THIS BREAKS THE OLD RECORD OF 40 DEGREES SET
IN 1986.
ALSO ONLY .49 INCHES OF RAIN AT JOHNSTOWN IN AUGUST. OLD RECORD
WAS .89 INCHES IN AUGUST 1894.
THIS AUGUST COOLEST IN SPOTS SINCE AUGUST 2014.
CTP WATCHES/WARNINGS/ADVISORIES
NONE.
SYNOPSIS...LAMBERT/DANGELO/MARTIN
NEAR TERM...LAMBERT/MARTIN
SHORT TERM...LAMBERT/MARTIN
LONG TERM...LAMBERT/MARTIN
AVIATION...BAUCO
CLIMATE...BANGHOFF/MARTIN/COLBERT
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