EGU25-10827, updated on 15 Mar 2025
https://doi.org/10.5194/egusphere-egu25-10827
EGU General Assembly 2025
© Author(s) 2025. This work is distributed under
the Creative Commons Attribution 4.0 License.
Analysis of an incorrect forecast of a torrential rain event in the UAE
Haraldur Ólafsson1 and Ólafur Rögnvaldsson2
Haraldur Ólafsson and Ólafur Rögnvaldsson
  • 1Department of Weather and Climate, Science Institute, University of Iceland, Iceland (haraldur68@gmail.com)
  • 2Belgingur Ltd., Reykjavik, Iceland (or@belgingur.is)

On 16 April 2024, the United Arab Emirates experienced torrential rain, with values exceeding 200 mm in less than a day.  In this study the WRF-based forecasting system Weather On Demand (WOD), developed by the Belgingur consortium in Iceland, is employed to explore the medium-range forecasts of the event, by simulations with initial values at different times.  A simulation of the event with 120h lead time was very bad, while a 72h simulation was quite accurate in terms of reproducing an extreme precipitation event.  A comparison of the simulations corresponding to the two forecasts reveals that the error in the 120h simulation is related to incorrect advection of dry air from the desert into the path of the convective storm across the Persian Gulf. The incorrect advection is associated with a wrong perturbation in the atmospheric flow, extending throughout the troposphere.  This perturbation error is associated with an erroneous simulation of a mesoscale convective complex occurring in the vicinity of Bahrain a day before the 16 April event. 

How to cite: Ólafsson, H. and Rögnvaldsson, Ó.: Analysis of an incorrect forecast of a torrential rain event in the UAE, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-10827, https://doi.org/10.5194/egusphere-egu25-10827, 2025.