📋 Forecast Verification
# FORECAST VERIFICATION BRIEF: Sunday, June 14, 2026
🌪️ GROUND TRUTH
WHAT ACTUALLY HAPPENED:
⛈️ WIDESPREAD SEVERE WEATHER OUTBREAK across the UPPER OHIO VALLEY, MID-ATLANTIC, AND NORTHEAST from mid-afternoon through late evening. The event unfolded in TWO DISTINCT WAVES: an earlier cluster across OHIO/WESTERN PENNSYLVANIA/GREAT LAKES (1600-2100 UTC), followed by a MORE INTENSE CORRIDOR across the MID-ATLANTIC (eastern PA/MD/VA/NC, 2200-0300 UTC).
🌪️ TORNADO REPORTS: 5 CONFIRMED
- WESTERN PA CLUSTER: 3 tornadoes in JEFFERSON COUNTY PA (2022-2041 UTC), including a confirmed tornado near Worthville and tree damage on SR-301
- OHIO: 2 tornadoes in COLUMBIANA COUNTY OH (2100-2117 UTC)
- All tornadoes concentrated in the UPPER OHIO VALLEY CORRIDOR during the earlier wave
💨 WIND REPORTS: 10 DAMAGING WIND EVENTS
- GREAT LAKES/OHIO: 61 mph gust at Clay Center OH (1730 UTC), 59 mph near Sandusky (1814 UTC), widespread tree/power line damage across ERIE/SANDUSKY/OTTAWA COUNTIES
- SOUTHEAST EARLY: isolated wind damage in PICKENS SC/FRANKLIN GA (1635-1726 UTC)
- Activity concentrated 1630-1900 UTC across the northern tier
🧊 HAIL REPORTS: 9 EVENTS
- Largest: 1.75" (GOLF BALL) IN NASH COUNTY NC (2321 UTC) and 1.25" IN CRAWFORD PA (2041 UTC), HAMPTON VA (2251 UTC), RIPLEY MD (2320 UTC)
- HEAVILY CONCENTRATED IN THE MID-ATLANTIC EVENING WAVE (2041-2324 UTC)
- Late timing confirms the SECOND, MORE ORGANIZED CORRIDOR was the primary severe producer
📡 WARNING ACTIVITY: 135 WARNINGS (17 tornado, 118 severe thunderstorm) across 14 offices
- BUSIEST OFFICES: CTP (30), AKQ (18), CLE (18), PBZ (18), LWX (13) — the MID-ATLANTIC CORE (CTP/AKQ/LWX = 61 warnings) and UPPER OHIO VALLEY (CLE/PBZ = 36 warnings) dominated
- TORNADO WARNINGS: concentrated in WESTERN PA and OHIO during the 2000-2200 UTC window
- Warning window: 1628 UTC → 0316 UTC — a 10 HOUR SEVERE WEATHER EVENT
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🎯 BOTTOM LINE
OVERALL PERFORMANCE: STRONG OPERATIONAL FORECAST WITH EXCELLENT REGIONAL TARGETING, THOUGH MAGNITUDE UNDERESTIMATED FOR THE MID-ATLANTIC CORRIDOR.
BIGGEST HITS:
✅ GEOGRAPHY: Day 1 and Day 2 both nailed the MID-ATLANTIC/UPPER OHIO VALLEY as the primary threat zones — the Slight Risk placement verified exceptionally well
✅ TIMING: Afternoon-evening window (1600-0300 UTC) verified perfectly; both outlooks correctly identified the PROGRESSIVE NATURE of the event
✅ PRIMARY HAZARD: DAMAGING WINDS were correctly forecast as the main threat and dominated the verified reports
✅ TORNADO THREAT RECOGNITION: Day 1 correctly highlighted EMBEDDED TORNADO POTENTIAL in the Upper Ohio Valley with stronger wind profiles — all 5 tornadoes occurred there
BIGGEST MISSES:
❌ MAGNITUDE UNDERESTIMATION: The MID-ATLANTIC CORRIDOR (especially EASTERN PA/MD/VA/NC) produced a MUCH MORE SIGNIFICANT EVENT than Day 2 anticipated — SPC collaboration notes mentioned "possible upgrade to Enhanced" but it remained Slight Risk
❌ PROBABILITY CALIBRATION: The 30% WIND PROBABILITIES for DelMarVa/SE PA/S NJ were justified, but the CONCENTRATION AND DURATION of the Mid-Atlantic event (61 warnings from CTP/AKQ/LWX alone) suggested ENHANCED RISK territory
❌ HAIL UNDERPLAY: While mentioned as "isolated," 9 HAIL REPORTS including GOLF BALL HAIL IN NC showed a MORE ROBUST HAIL ENVIRONMENT than anticipated, especially in the evening Mid-Atlantic wave
KEY TAKEAWAYS:
🔥 TWO-WAVE STRUCTURE: The event split into an EARLY OHIO VALLEY TORNADO/WIND PHASE (1600-2100 UTC) and a LATER, MORE INTENSE MID-ATLANTIC SEVERE WIND/HAIL PHASE (2200-0300 UTC) — Day 1 better captured this evolution
🎯 ENHANCED VS. SLIGHT DEBATE: Day 2's collaboration notes about a POSSIBLE ENHANCED UPGRADE were prescient — the WARNING DENSITY, DURATION, AND REPORT CONCENTRATION across the Mid-Atlantic core supported that level, especially given the 1500-2500 J/KG MLCAPE and organized clusters
📍 TORNADO PLACEMENT: The WESTERN PA TORNADO CLUSTER verified the Day 1 emphasis on STRONGER WIND PROFILES/EFFECTIVE SHEAR in the Upper Ohio Valley — tornadoes stayed north of the higher instability but weaker shear zone
⚡ DCAPE/INVERTED-V: Local AFDs (RNK, AKQ) emphasized DCAPE 1000-1300 J/KG and DRY MID-LEVEL AIR — the verified DAMAGING WIND DOMINANCE and WATER-LOADED DOWNBURSTS (FFC noted 45 mph at their office) confirmed this as the PRIMARY MECHANISM
🌧️ MOISTURE GRADIENT: The NORTHWARD EXTENT OF MOISTURE (Day 2 uncertainty: "low 60s F dewpoints into PA/NY") ended up MORE ROBUST THAN EXPECTED, fueling the PROLONGED MID-ATLANTIC EVENT into the evening hours
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🗺️ SPC VERIFICATION
DAY 2 OUTLOOK (ISSUED 0015 UTC JUN 13) VS. DAY 1 OUTLOOK (ISSUED 1254 UTC JUN 14) VS. REALITY:
📍 GEOGRAPHY:
- DAY 2: Slight Risk across UPPER OHIO VALLEY TO MID-ATLANTIC — broadly correct but LESS SPECIFIC
- DAY 1: Refined Slight Risk with BETTER FOCUS on the NORTHEAST/APPALACHIANS/MID-ATLANTIC corridor — closer to verified activity
- REALITY: The MID-ATLANTIC CORRIDOR (eastern PA through VA/NC) was the BULLSEYE, with a secondary UPPER OHIO VALLEY tornado zone — Day 1's refinement was SPOT-ON
⚡ SEVERE THREAT MAGNITUDE:
- DAY 2: Acknowledged 30% WIND PROBABILITIES for DelMarVa/SE PA/S NJ and noted "HIGHER COVERAGE PROBABILITIES/UPGRADE TO ENHANCED COULD BE NEEDED" — this was PRESCIENT BUT NOT ACTED UPON
- DAY 1: Maintained Slight Risk but described "SEVERAL ORGANIZED CLUSTERS CAPABLE OF SCATTERED DAMAGING WIND GUSTS" and "LOCALLY HIGHER CONCENTRATIONS OF WIND DAMAGE" — language suggested HIGHER-END SLIGHT
- REALITY: The 135 WARNINGS, 10 WIND REPORTS, 9 HAIL REPORTS, AND 10 HOUR DURATION across the Mid-Atlantic core JUSTIFIED ENHANCED RISK, especially given the 61 WARNINGS FROM CTP/AKQ/LWX ALONE
🌪️ TORNADO THREAT:
- DAY 2: Mentioned "ISOLATED TORNADO POSSIBLE" almost as an afterthought
- DAY 1: Upgraded emphasis: "A BRIEF TORNADO AND/OR HAIL COULD ALSO OCCUR GIVEN THE RELATIVE STRENGTH OF THE WIND PROFILES" in the Upper Ohio Valley — MUCH BETTER recognition
- REALITY: 5 TORNADOES, ALL IN THE UPPER OHIO VALLEY (western PA/Ohio) during the 2000-2200 UTC WINDOW — Day 1's WIND PROFILE EMPHASIS was VALIDATED
🧊 HAIL THREAT:
- DAY 2: "ISOLATED HAIL" mentioned but downplayed
- DAY 1: "SOME HAIL" expected, especially with semi-discrete supercells
- REALITY: 9 HAIL REPORTS, including GOLF BALL HAIL IN NC and HALF-DOLLAR HAIL IN MULTIPLE MID-ATLANTIC LOCATIONS — MORE WIDESPREAD THAN FORECAST, particularly in the EVENING MID-ATLANTIC WAVE
🕐 TIMING:
- DAY 2: "AFTERNOON TO EARLY EVENING" for Mid-Atlantic, "THROUGH THE EVENING" for Upper Ohio Valley
- DAY 1: "AFTERNOON AND EVENING" — slightly longer window
- REALITY: 1630 UTC → 0316 UTC (10 hours) — the event RAN LATER than Day 2 anticipated, especially the MID-ATLANTIC PHASE, which didn't peak until 2200-0100 UTC. Day 1's broader window was CLOSER.
📊 FORECAST EVOLUTION & LOCAL AFD INSIGHTS (WEIGHTED BY TIER):
TIER 1 (CORE RISK AREAS) — RNK, LWX, AKQ, PHI:
- RNK (BLACKSBURG VA): Emphasized DCAPE 1000-1300 J/KG, INVERTED-V PROFILES, AND DRY MID-LEVELS — correctly identified DAMAGING WIND DOWNBURSTS as the primary mechanism. Noted MLCAPE >1500 J/KG across the Piedmont.
- AKQ (WAKEFIELD VA): Highlighted 30% WIND PROBABILITY and noted SPC COLLABORATION ABOUT POSSIBLE ENHANCED UPGRADE — showed OPERATIONAL AWARENESS that the threat was HIGHER-END SLIGHT. Emphasized 1500-2000 J/KG MLCAPE and 30-40 KT EFFECTIVE SHEAR.
- LWX (BALTIMORE/DC): By evening, noted the SEVERE THREAT HAD DIMINISHED but emphasized the PROLONGED LIGHTNING/FLOODING THREAT — captured the MESSY, LONG-DURATION nature of the event.
- PHI (MT. HOLLY NJ): By overnight, the SEVERE WEATHER THREAT HAD ENDED but noted ELEVATED CREEK/STREAM LEVELS near I-95 — highlighted the TRANSITION FROM SEVERE TO FLOODING as the event wound down.
TIER 2 (SECONDARY AREAS) — CLE, PBZ, ILN, BGM:
- CLE (CLEVELAND): Correctly forecast DAMAGING WINDS IN EXCESS OF 60 MPH and captured the GREAT LAKES/LAKE ERIE ENHANCEMENT — the 61 MPH GUST AT CLAY CENTER OH and SANDUSKY damage verified this.
- PBZ (PITTSBURGH): Emphasized DEPENDENCE ON MORNING ACTIVITY and the RESULTING AFTERNOON ENVIRONMENT — showed GOOD MESOSCALE AWARENESS but UNDERESTIMATED TORNADO POTENTIAL until the event unfolded.
- BGM (BINGHAMTON NY): Noted STEEP LOW-LEVEL LAPSE RATES OFFSETTING LOWER CAPE — captured the WIND-DOMINANT PROFILE even in marginal instability zones.
DAY 2 → DAY 1 EVOLUTION:
The forecast IMPROVED SIGNIFICANTLY from Day 2 to Day 1 in TORNADO THREAT RECOGNITION (western PA/Ohio) and TIMING REFINEMENT, but BOTH DAYS UNDERESTIMATED THE MAGNITUDE of the Mid-Atlantic corridor event. Day 2's COLLABORATION NOTES about a POSSIBLE ENHANCED UPGRADE were the KEY MISSED OPPORTUNITY — had SPC pulled the trigger on Enhanced for the DelMarVa/eastern PA corridor, it would have BETTER MATCHED the verified WARNING DENSITY AND REPORT CONCENTRATION.
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