Date of Issue: January 14, 2023
What are the usual JFM conditions?
| January-February-March RAINFALL CLIMATOLOGICAL NORMAL (30YEARS) |
||
|---|---|---|
| Canefield Airport | Douglas-Charles Airport | |
| Normal Accumulation | 146.2 to 263.3mm | 252.0 to 373.8mm |
| Number of Wet Days | 41 to 23 days | 21 to 30 days |
| Number of 7-day Wet Spells | 0 to 2 | 0 to 1 |
| Number of 7-day Dry Spells | - | 0 to 1 |
| TEMPERATURE (15YRS AVERAGES) | ||
| Average Maximum | 29.9°C to 30.3°C | 28.6°C to 28.9°C |
| Average Mean | 25.8°C to 26.0°C | 25.2°C to 25.6°C |
| Average Minimum | 21.5°C to 21.8°C | 21.9°C to 22.3°C |
What is the forecast for this JFM season?
- Rainfall:
- There is medium confidence that rainfall accumulation is likely to remain at least as high as usual;
- Rainfall for January so far has already exceeded 146.2mm at Canefield while DouglasCharles has been drier;
- An increase in the number of wet days is likely, particularly over the western and southern parts of the island;
- No significant shift in the number of very wet spells which could result in flash floods is expected, with the usual one event likely;
- There is a low chance of having a 7-day dry spell;
- At this time, there is no concern for drought conditions;
- Drier than usual rainfall is likely during the second half of the dry season, which may increase the chance of bush fires;
- Temperature:
- Temperatures are expected to be generally comfortable as the cool season progresses;
- Daytime and night-time temperatures are likely to be close to the usual or even slightly lower;
Note: The level of forecast accuracy and certainty decreases as the time increases. This is inherent to all model projections. Therefore, there is less confidence after 48 hours. Model projections may change significantly daily.
What factors are influencing this forecast?
- El Niño Southern Oscillation (ENSO)
- Recent observations: Sea Surface Temperatures (SSTs) in the eastern Pacific remain below normal (-1.0°C); 2022 was a La Niña year;
- Model forecast and guidance: ENSO neutral conditions are possible in JFM (50-60% confidence) with higher confidence of this by AMJ. El Nino may develop afterwards;
- Expected impacts on rainfall and temperatures: La Niña tilts the odds to a wetter JFM. ENSO neutral offers little predictability in seasonal forecasting;
- Climate conditions in the Tropical North Atlantic (TNA) and the Caribbean Sea
- Recent observations: SSTs are around 0.5°C above average in much of the sub-tropical North Atlantic, but near average in the Caribbean Sea and the Tropical North Atlantic (TNA);
- Expected conditions: Models are forecasting SST to remain between 0-0.5°C above average, across the Caribbean and in the sub-tropical North Atlantic;
- Expected impacts: Warm SSTs in and around the Caribbean tend to contribute to higher air temperatures with above-average humidity, seasonal rainfall totals and an increased frequency of extreme rainfall;