Saturday's Cold Front - Ireland/N. Ireland

[martinastro]

Another low pressure system will make it's presence felt this weekend when a series of fronts will cross the country from Fri to Sat. First an occluded front, however of interest is the intense cold front which will affect many areas on Saturday July 11th which has the potential to produce serious long duration rainfall with a high risk of severe flooding in places. There's also a chance this cold front could be convectively active with the occasional rumble of thunder with strong winds. A squall line may not be out of the question, just waiting to see what the experts have to say closer to the time. The post frontal airmass during Sun, Mon, and Tues should introduce showers with a risk of isolated t-storms. Funny how July has taken this pattern in crecent years!.

Unfortuantely we will probably miss the ISS and shuttle fuel tanks on Sat night however with clearer air from Sun onwards we should see the exciting space chase between the two...looking forward to it.

[martinastro]

TORRO CONVECTIVE DISCUSSION 2009/024

A TORRO CONVECTIVE DISCUSSION has been issued at 11:45 GMT on Saturday 11th July 2009

Valid from/until: 11:45-21:00GMT on Saturday 11th July 2009 for the following regions

Parts of (see map)

Eire

N Ireland

THREATS

Wind gusts to 50-55mph; isolated tornadoes; heavy rain; occasional CG lightning; hail

DISCUSSION

Strong Atlantic depression for this time of year will push a well-marked cold front across the British Isles over the next 18 hours or so. Across Eire, strong upper divergence will be co-located above the cold front/triple point. In addition, a marked dry intrusion will cause the front to split. The lift associated with the diveregence may help to release potential instability bringing the risk of embedded thunderstorms. Strong low-level shear means that these could produce marginally severe wind gusts. Generally, any storms which do develop will be elevated above the boundary layer - however, strong low-level convergence along the front could mean that some boundary layer air could get ingested into the storms...given marked low-level veering, if this occurs, a tornado or two is possible.

The lack of surface-based instability and the widespread cloud/rain occurring around this depression, the risk is deemed too low to warrant a WATCH.

Forecaster: RPK.