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Ensemble guidance in support of PREDICT: 2011
Introduction
The primary purpose of the National Science Foundation's PRE-Depression Investigation of Cloud Systems in the Tropics (PREDICT) project is to advance our understanding of why tropical disturbances develop, or do not develop, into tropical cyclones. The ensemble forecast products prepared daily on this website can be used as follows:
(1) To identify probabilities of (a) favourable environmental conditions and (b) exceedance of critical values of storm-centric metrics including circulation, thickness anomaly, vorticity, mean sea level pressure, upper-level divergence and low-level convergence, associated with named pouch systems.
(2) To identify potential future systems worthy of investigation.
(3) To offer 10-day forecast guidance and probabilities for longer-term preparation.
Associated objectives of this project include an improved understanding on how predictability of tropical cyclogenesis is limited by environmental factors, such as vertical wind shear, mid-lower tropospheric humidity, and the specification of the initial vortex itself.
ECMWF and NCEP Ensemble Prediction System graphical products are available daily for 00 UTC runs between 15 August - 30 September 2011. (ECMWF products require a userid and password)
NCEP: by 3:30am EDT. ECMWF: by 7:30am EDT. Both sets of plots are re-run with pouches overlaid, normally around 10:00am EDT. PDFs become available at the same time.
In the tracker, all 3 of the following criteria must be satisfied for a system to be deemed a tropical cyclone:
(a) Area-averaged 700-850 hPa relative vorticity exceeds 5 x 10^-5 s^-1 (middle blue contour on spaghetti plot).
(b) Local thickness anomaly exceeds 40 m (orange contour on spaghetti plot).
(c) Local minima of mean sea level pressure less than 1010 mb.
Students and Collaborators
Will Komaromi (Ph.D. student), Jonathan Labriola (undergraduate research assistant), Ryan Torn (SUNY Albany), Jason Dunion (NOAA/AOML/HRD), the PREDICT team, NOAA/NWS/NCEP National Hurricane Center.
Links