National Institute of Meteorology and Hydrology


NIMH global models are used to produce the medium-term forecasts:

  1. European Centre for Medium-Range Weather Forecasts(ECMWF), of which Bulgaria has been a cooperating member since 2009;
  2. National Centers for Environmental Prediction - NOAA - Global Forecasting System - GFS;
  3. MeteoFrance – ARPEGE;
  4. and others.

Seasonal Forecast


More detailed seasonal forecast (only in Bulgarian) HERE

What Is a Seasonal Forecast?


Seasonal forecast refers to average values of weather elements over a period of 3 months and are in terms of probabilities. Unincreased probability of an event below, above or around the norm is 33.3%. Thus, it can be expected that, climatically, the seasons fall with equal probability (33.3%) into one of the three categories: around the norm, below the norm and above the norm. The purpose of seasonal forecasts is to check through various statistical and numerical methods whether there is an increased probability that an upcoming season will fall into any of the three categories for the respective element. The below, above or around normal categories used for the purposes of this seasonal forecast are determined relative to the 1980-2009 normal. The small spatial scales of Bulgaria compared to the scales of the climatic structures that determine the nature of the seasons, as well as the uncertainty in the seasonal forecasts, make us use an index to characterize the seasons (and months) for the country as a whole. For the individual gradations of the index, traditional color gradations given in the second table are used. Seasonal forecasts with different degrees of probability are correspondingly assigned similar color degrees, which are also given in the second table. The first table shows the realized indices for the expired or expiring months of the current season and the forecast for each of the upcoming three months as well as for the current and upcoming calendar season.