Yesterday, we had some heavy dirty rain here in Felanitx, albeit of a very short duration. The rain must have come from Africa with the big splashes holding dust or even sand from the Sahara if one considers the evidence on the cars in our street.

The first week or second of September is usually a time of rain and storm, even tornadoes, sometimes in the form of the Gota Fría, when very cold air meets the warm Mediterranean Sea. I think it is too early for the Cold Drop yet, but, AEMet (the Spanish Meteorological Agency) is giving a weather warning for the Balearic Islands for today. Rain and Storm are predicted for the island of Mallorca, and for Menorca, storms and even Rissagas (inverted Tsunamis). The storm warning (yellow Alert) is only given for today; from tomorrow, the weather should be back to normal with hardly any showers and almost certainly, no storm.

The European Storm Forecast Experiment gives a Level 1 storm forecast for SE/E/NE Spain for today. Please allow me to quote:

…. Gradually weakening upper low slowly moves eastwards during the forecast and affects the extreme W-Mediterranean during the late night hours. Part of an extensive Saharan Air Layer to the south becomes included into the system and hence allows quite dry air to spread northwards over Spain and the W-Mediterranean during the day. However, strengthening LL baroclinic zone over Morocco and the E-Strait of Gibraltar, moistening atop the warm SSTs of the Mediterranean and deep isentropic lift ahead of the eastward pushing trough allow overall moisture recovery during the evening and night hours over a broad/deep atmospheric column.

During the day, thunderstorms and showers keep going all day long over Portugal and Spain as some diabatic heating, forcing and cold mid-levels assist in instability and initiation. Placed beneath center of upper low, kinematics remain weak, so pulsating storms with marginal hail/strong wind gusts will be the predominant risk.

Later on /afternoon hours onwards/ overall conditions become more supportive for initiation along the SE/E/NE coast of Spain and also offshore during the late night hours, as thermal ridge shifts eastwards, reducing CIN. Enhanced dynamic lift, 1000 J/kg MLCAPE and 15-20 m/s 0-6 km bulk shear allow well organized multicells to form with large hail and strong/severe wind gusts. An isolated very large hail event can’t be ruled out, although displacement of best shear/CAPE axis lowers confidence somewhat (also below the level 2 threshold). Thunderstorm coverage and intensity increases offshore during the end of the forecast.

Further east, over the west-central Mediterranean (including Corsica and Sardinia), forecast soundings indicate an increase in CIN during the day as thermal ridge moves in from the west. Nevertheless, weak vorticity maxima eject out of the base of the Iberian Peninsula trough and may allow an isolated, elevated thunderstorm to evolve. Model discrepancies and uncertainty of placement and timing of any disturbance preclude a broad thunderstorm area for now. However can’t rule out a very isolated thunderstorm all the way to the Tyrrhenian Sea.

Friends of ours wanted to go searching for some Raor Razorfish today. The sea may be too rough for a boat outing, though. The Raor may have to wait until tomorrow.

The photo was taken in Felanitx, Mallorca, Baleares, Spain. The date: September 2nd, 2011. The time was 10:51:48. The map (centre) was borrowed from the Internet, courtesy of AEMet.es. The chart (bottom) was borrowed from the Internet, courtesy of estofex.org.

Muchas gracias

and thank you very much.