Area Forecast Discussion - Aveiro

Issued: Wed, Jan 7, 9:50 PM | Valid through: Wed, Jan 21

KEY POINTS

Prolonged rainfall event from 2026-01-12 onward, with potential for heavy rain and gusty winds (notable gusts up to 69km/h on 2026-01-20 and 2026-01-21).
Marginal temperature fluctuations near 0°C are not anticipated; thus, no frozen precipitation concerns for Aveiro.
High model uncertainty in precipitation timing/intensity for the near term, with oscillating solutions noted.

SYNOPSIS

A complex, evolving synoptic pattern is expected to influence the Aveiro region through the forecast period. Initially, a weak trough axis will linger nearby, supporting light rain showers through the near term. A more pronounced low-pressure system, fueled by a deepening upper-level trough, is anticipated to develop over the Atlantic by the short term, leading to a prolonged period of moderate to heavy rainfall from 2026-01-12 onward. This system's evolution will be influenced by the interaction of a strong jet streak and a deepening negative tilt trough, promoting robust precipitation and gusty winds.

NEAR TERM (0-24 hours)

0-12 hours (2026-01-07T22:00-2026-01-08T10:00):

Current Setup: As of 2026-01-07T21:50Z, a shallow layer of dry air persists over Aveiro, with skies clearing and temperatures dipping to 6°C.
Forecast: Through the overnight hours, skies will remain mostly clear, with temperatures stabilizing near 5-6°C. By dawn (2026-01-08T06:00), increasing cloudiness is expected as a weak shortwave trough approaches from the northwest.
Precipitation: Isolated light rain showers (0.1-0.5mm) may develop by 2026-01-08T12:00, with precipitation probabilities increasing to 20-25% by midday. Model guidance indicates a low-confidence scenario for precipitation onset, given the oscillating solutions and lack of strong forcing mechanisms.

12-24 hours (2026-01-08T10:00-2026-01-09T00:00):

Synoptic Evolution: The approaching shortwave trough will introduce a more unsettled regime, with light rain becoming more widespread by the evening (2026-01-08T18:00-2026-01-08T22:00).
Uncertainty: Model solutions diverge on the timing and intensity of precipitation, with some members (notably the 2026-01-07T18:47:01.310Z run) suggesting a delayed onset. Gusts up to 40-44km/h are possible during the evening, coinciding with the strongest pressure gradient.
Temperature: Daytime highs will rise to 14°C, with minimal diurnal variation due to persistent cloud cover.

SHORT TERM (24-72 hours)

24-48 hours (2026-01-09T00:00-2026-01-10T00:00):

Pattern Transition: A zonal flow regime will briefly dominate, maintaining a steady influx of Atlantic moisture. This will sustain light to moderate rain showers, with totals of 6.4mm anticipated on 2026-01-09.
Uncertainty: Ensemble spread indicates variability in precipitation intensity, dependent on the strength of the low-level jet and the positioning of the surface trough.

48-72 hours (2026-01-10T00:00-2026-01-11T00:00):

System Amplification: The upper-level trough is forecast to deepen, promoting a more organized low-pressure system. This will lead to increasing precipitation coverage and intensity, with gusts strengthening in response to the tightening pressure gradient.
Key Uncertainties: The rate of trough deepening and the subsequent low-pressure system's track remain uncertain, impacting the timing and magnitude of rainfall.

LONG TERM (beyond 72 hours)

A persistent, active pattern is anticipated, with a strong, southwesterly flow maintaining a rich supply of moisture from the Atlantic. This will support prolonged periods of moderate to heavy rain from 2026-01-12 onward, with embedded heavier bursts possible. The large-scale pattern favors a continued risk of gusty winds, particularly on 2026-01-20 and 2026-01-21, as noted in the model output.

CONFIDENCE & KEY UNCERTAINTIES

High Confidence: Prolonged rainfall event from 2026-01-12 onward, with heavy rain and gusty winds.
Moderate Confidence: Precipitation timing/intensity in the near term (0-24 hours), given oscillating model solutions and weak forcing.
Low Confidence: Exact track and deepening rate of the low-pressure system in the short term, which will significantly influence rainfall totals and wind gusts.
Microclimate Effects: Coastal convergence zones may enhance rainfall rates in localized areas, particularly near Aveiro's coastline, though models may not fully resolve these features.

Aveiro Area