A Study of the Extratropical Reintensification of Former Hurricane Earl Using Canadian Meteorological Centre Regional Analyses and Ensemble Forecasts
Bibliographic record
Abstract
Former Hurricane Earl reintensified rapidly while traveling through Canadian waters in September 1998. Its central pressure decreased 40 hPa over a 36-h period, and it produced heavy rain on Cape Breton Island, Nova Scotia, and over Newfoundland. A diagnostic study is conducted from a potential vorticity (PV) perspective using Canadian Meteorological Centre (CMC) regional analysis data. Former Hurricane Earl's rapid redevelopment was related to the interaction between two preexisting positive PV anomalies: a diabatically generated low-level anomaly and an upper-level anomaly. This process was accompanied by a cold air intrusion and warm air ''wrapping up'' process. As well, the behavior of the operational CMC numerical weather prediction models is examined using output from the ensemble forecast system (giving 10-day forecasts, with eight members and one control run) integrated from three different initial times (0000 UTC on each of 3, 4, and 5 September 1998). Some members failed to maintain former Hurricane Earl's observed closed cyclonic circulation during the weakening period, and subsequently developed only a weak low pressure system. Others maintained the identity of former Hurricane Earl throughout both the weakening and reintensifying periods. Static PV inversions suggest that the more successful forecasts of Earl's reintensification were associated with preferentially strong lowertropospheric cyclonic circulations induced by the upstream upper-tropospheric PV maximum. This induced lowerlevel flow also produced the very large-amplitude low-level thermal perturbations characteristic of a deepening baroclinic low.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".