Storm Forecast
Valid: Wed 21 Mar 2012 06:00 to Thu 22 Mar 2012 06:00 UTC
Issued: Tue 20 Mar 2012 23:09
Forecaster: PUCIK
A level 1 was issued for Northeastern Spain mainly for excessive rainfall and tornadoes.
SYNOPSIS
A blocking pattern is prevalent over Europe with significant ridge stretching from Northern Africa to Central Europe and no major change anticipated in the following days. Polar jet-stream is deflected around this feature, covering only central Scandinavia and Russia. Regarding lower level features, a center of the large high pressure system is located under the apex of the mid-level ridge, while the high itself will cover most of Europe, excluding Northern Scandinavia and parts of Russia. Stable and dry airmass will cover most of Europe, detrimental to any DMC, except for westernmost Mediterranean where a plume of steep lapse rates airmass is advected from Northern Africa on the fringes between the ridge and a cut-off low over the Iberia.
DISCUSSION
... Northeastern Spain ...
The aforementioned plume of steep lapse rates is advected over the Balearic Sea, contributing to the generation of few hundreds J/kg of MLCAPE. With the generation of a small scale low pressure system over the Central Iberia and contribution of the Pyrennees, channeling of the low level flow is anticipated in this region with a low level jet reaching 15-20 m/s at 850 hPa level. High values of LLS and moderate values of SREH are generated by this enhanced LLJ. Models generally agree on simulating prolonged wave of precipitation over the region. This, strong and moist LLJ, along with upslope flow confide in the excessive precipitation threat over the region with possibility of parallel stratiform MCS formation.
Tornado threat will be more limited areally to the regions where some surface based instabiltiy will be present - i.e. especially those close to the coastline. Despite shear profiles will be quite favorable, low degree of SBCAPE and questionable presence of storms in isolated nature will likely limit the threat furthermore.
