Development of LAMP Convection and Cloud-to-Ground Lightning Forecast Guidance for Alaska and Beyond

The Meteorological Development Laboratory of the National Weather Service is developing Localized Aviation MOS Program (LAMP) convection and cloud-to-ground (CG) lightning forecast guidance to support Alaska aviation and wildfire management services. Such forecast guidance is needed, as aviation is a critical method of transportation in Alaska, forest fires burn ten times more acreage in Alaska than any other state of the United States (US), and 93% of the burned area is from lightning-ignited fires. Alaska LAMP convection and CG forecast guidance is patterned after similar guidance for the conterminous US (CONUS), which has been operational since April 2014 and last upgraded in January 2018.

For Alaska, the LAMP convection event is defined as the occurrence of radar composite reflectivity of ≥ 35 dBZ and/or ≥ 1 CG lightning strokes in a 24-km gridbox during a 1-h period. The LAMP lightning predictand consists of the lightning component of the convection predictand. With these predictands, regression equations are developed and applied to produce 1-h convection and 1-h CG lightning probability and “potential” forecasts on a 12-km base grid in the 1-38 h range. These forecast guidance elements are interpolated to Alaska aviation stations and the National Blend of Models (NBM) 3-km Alaska grid for dissemination to users.

LAMP convection and lightning predictors are derived from multiple data inputs: MRMS and “merged” CG lightning observations, fine scale convection and CG lightning climatology, and MOS 1-h convection and 1-h lightning probabilities, which may be based on RAP, NAM, ECMWF, and GFS/FV3 model output. The conference presentation will include describing challenges in using these diverse Alaska datasets to produce the LAMP convection and lightning forecast guidance. Portions of this material are based on work supported by the Joint Technology Transition Initiative (JTTI) Program within NOAA/OAR Office of Weather and Air Quality.