699
FXUS61 KCTP 301139
AFDCTP
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
739 AM EDT SUN AUG 30 2026
WHAT HAS CHANGED
* LEVEL 2 SEVERE THUNDERSTORM RISK INTRODUCED FOR TUESDAY (9/1)
KEY MESSAGES
1) LATE SUMMER HEAT+HUMIDITY TO CLOSE AUGUST AND OPEN SEPTEMBER
2) BOUTS OF HEAVY RAIN & SEVERE STORMS POSSIBLE MONDAY-WEDNESDAY
DISCUSSION
KEY MESSAGE 1: LATE SUMMER HEAT+HUMIDITY TO CLOSE AUGUST AND
OPEN SEPTEMBER
STRONG UPPER RIDGE EXPANDING EAST-NORTHEASTWARD FROM THE
SOUTH CENTRAL PLAINS THROUGH THE TN VALLEY INTO THE SOUTHERN
MID ATLANTIC AND SOUTHEAST STATES WILL DELIVER A STRETCH OF
ABOVE NORMAL LATE SUMMER WARMTH AND VERY HUMID CONDITIONS TO
CLOSE OUT AUGUST AND KICKOFF SEPTEMBER. FORECAST MAX/MIN
TEMPERATURES ARE PROJECTED TO RISE SEVERAL DEGREES ABOVE THE
HISTORICAL AVERAGE SUNDAY-THURSDAY WITH THE LARGEST DEPARTURE
FROM NORMAL (+10-20F) FOUND IN MIDWEEK OVERNIGHT LOWS. THE LATE
SUMMER HEAT IS FORECAST TO PEAK TUESDAY AND WEDNESDAY WITH MAX
HEAT INDICES APPROACHING ADVISORY LEVELS IN THE MID TO UPPER 90S
ACROSS PARTS OF SOUTH CENTRAL PA. THE WELL ABOVE NORMAL
TEMPERATURES COMBINED WITH HIGH HUMIDITY AND VERY WARM OVERNIGHT
LOWS WILL RESULT IN LEVEL 2 (MODERATE) TO LEVEL 3 (MAJOR)
HEATRISK VALUES TUESDAY AND WEDNESDAY. INCREASING TROUGHING
ACROSS THE NORTHEAST U.S. SHOULD DROP TEMPERATURES BACK TOWARD
SEASONAL CLIMO BY FRIDAY/SATURDAY.
KEY MESSAGE 2: BOUTS OF HEAVY RAIN AND SEVERE STORMS POSSIBLE
THROUGH LATE WEEK
A SERIES OF MID LEVEL IMPULSES TRACKING EASTWARD ALONG THE
NORTHERN PERIPHERY OF THE ELONGATED 500MB RIDGE WILL INTERACT
WITH ANOMALOUS MOISTURE/INSTABILITY AND STRONG FLOW ALOFT TO
PRODUCE A FEW EPISODES OF HEAVY RAINFALL AND POSSIBLE SEVERE
WEATHER THROUGH LATE WEEK. THERE ARE TYPICAL TIMING AND
AMPLITUDE DIFFERENCES OF THE SMALLER SCALE DISTURBANCES THAT
WILL NEED TO BE RESOLVED, BUT THE OVERALL CONVECTIVE SIGNAL FROM
OPERATIONAL/ENSEMBLE/ML/AI GUIDANCE IS SUPPORTIVELY BULLISH.
THERE IS A GROWING SIGNAL FOR SEVERE STORMS AND HEAVY RAIN ON
TUESDAY AND WEDNESDAY. SPC INTRODUCED A LEVEL 2 SEVERE T-STORM
RISK FOR D3/TUESDAY AND MAINTAINED THE 15% OR LEVEL 2 EQUIVALENT
RISK FOR D4/WEDNESDAY. WPC CONTINUES TO COVER PARTS OF CPA WITH
LEVEL 1 EXCESSIVE RAINFALL OUTLOOKS WHICH MAY BE REFINED/UPGRADED
AS THE CONVECTIVE DETAILS BECOME MORE CLEAR AND CONFIDENCE IN
TIMING AND LOCATION INCREASES.
AVIATION /12Z SUNDAY THROUGH THURSDAY/
WIDESPREAD VFR (VSBYS AND CIGS) NOTED ACROSS MUCH OF PA THIS
MORNING WITH VARIABLE AMOUNTS OF MID AND HIGH LEVEL CLOUDS
DRIFTING ESE ACROSS THE NORTHERN 2/3RDS OF THE STATE.
CONVERGENCE AXIS BETWEEN LOW LEVEL SOUTH/SOUTHWESTERLY FLOW
WAS LOCATED JUST TO THE WEST/NW OF CHESAPEAKE BAY AND WAS
LEADING TO THE FORMATION OF AN AREA OF MVFR STRATOCU CLOUDS
THAT WAS DRIFTING NORTHEAST OVER PORTIONS OF THE LOWER SUSQ
VALLEY, MAINLY TO THE EAST OF RT 15.
THIS AREA OF STRATO CU WILL ADVECT FURTHER NORTH/NORTHEAST AND
IMPACT KMDT, KCXY AND KLNS THROUGH THE LATE MORNING HOURS, WITH
CIGS AOB 2000 FT AGL AT TIMES. TEMPO GROUPS FOR BUMPS UP IN THE
CIG HEIGHTS BY SEVERAL HUNDRED FEET OR MORE ARE CURRENTLY IN
PLACE AT KMDT AND KLNS FROM 14-16Z TODAY AS THE LOW LEVEL WIND
DIRECTION VEERS A BIT MORE TO THE SW AND VERTICAL MIXING DEEPENS
WITH DRIER AIR BEING ENTRAINED INTO/ERODING THE CLOUD DECK.
OVERALL FOR TODAY, A LIGHT SFC W/SW WIND OF 5-10 KTS DEVELOPS
ACROSS CENTRAL PA. ANY MVFR CIGS OVER THE LOWER SUSQ VALLEY
SHOULD LIFT/MIX OUT BY 16Z. A FEW SHRA OR TSRA COULD DEVELOP
LATER IN THE DAY, ESP ACROSS NORTHERN PA AS AN UPPER LEVEL
DISTURBANCE SLIDES SE FROM THE GREAT LAKES REGION, BUT MOST OF
THE DAY SHOULD BE DRY.
OUTLOOK...
MON-THU...SCATTERED SHRA/TSRA WITH BRIEF RESTRICTIONS POSSIBLE;
MORNING FOG POSSIBLE.
CTP WATCHES/WARNINGS/ADVISORIES
NONE.
WHAT HAS CHANGED...STEINBUGL
KEY MESSAGES...STEINBUGL
DISCUSSION...STEINBUGL
AVIATION...LAMBERT/EVANEGO
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