Convective/Thunderstorm Discussion: Autumn/Winter 2016-17

Convective Weather saying some potential but uncertain over the Irish Sea this evening possibly moving into Eastern Northern Ireland / SW Scotland.

Recent sferic in Galway.

All quiet atm except for the North of Scotland

Day 2 Convective Outlook
VALID 06:00 UTC Thu 22 Sep 2016 - 05:59 UTC Fri 23 Sep 2016

ISSUED 20:35 UTC Wed 21 Sep 2016

ISSUED BY: Dan

In the post-frontal environment, cold mid-levels atop relatively warm SSTs will steepen lapse rates as a sharp upper trough migrates NE-wards, allowing deep convection to bring showers, sometimes in more organised bands, with a few weakly-electrified thunderstorms possible too. The lightning risk will be greatest (but considered sub-SLGT criteria) over Ireland and Northern Ireland on Thursday afternoon, the focus then shifting NE with time to W Scotland by evening. Gusty winds and hail up to 1.0-1.5cm in diameter will be possible with the best organised showers/storms.

Interesting to see today the almost complete lack of sferics over land. What convection formed over the relatively warm sea was as Convective Weather predicted ' weakly electrified ' and ran out of juice very quickly not making it onto land. The sea temp at the M4 Buoy ( 40 NM off the Donegal coast ) was 14C today and the M6 ( deep Atlantic ) was 15.1C , some stations in the North of the country struggled to get an air temp above 14C today.

I wonder would the couple of very cool nights have had an effect in not producing electrical activity over land today, soil temps yesterday between 12.5C and 14.5C and I presume would have been a bit lower today, in other words not warm enough to lift air parcels or keep the convection powered up?

By the way, Met Eireann dropped the forecast for Thunderstorms the last couple of days before today, well done to them.

Convective Outlook: Sun 25 Sep 2016




VALID 06:00 UTC Sun 25 Sep 2016 - 05:59 UTC Mon 26 Sep 2016

ISSUED 16:23 UTC Sat 24 Sep 2016

ISSUED BY: Dan

Strong DLS along the cold front boundary may continue to produce some elements of line convection, especially on the leading edge of the precipitation field, as the front clears eastwards across E/SE England on Sunday morning - although the risk of lightning is very low (near 5-10%).


Otherwise, the post-frontal environment will exhibit notably steep lapse rates as a sharp upper trough slides NE from the Atlantic across the British Isles. Numerous showers, as a result of cold air aloft atop relatively warm SSTs, will be ongoing at the beginning of this forecast period over portions of Ireland, and will tend to become more widespread in coverage through the day across many areas - although very few in sheltered eastern parts. Lightning will be rather sporadic in nature, hence the broad LOW threat level issued, but a favourable overlap of instability phasing with peak diurnal heating suggests a better chance of showers becoming electrified across northern parts of Ireland into Northern Ireland on Sunday afternoon - hence a SLGT issued here.

The strongest cells will be capable of producing gusty winds and hail up to 1.5cm in diameter.

Met Eireann mentioning the possibility of heavy thundery showers the next couple of days. Not much rain showing up on the models Thurs but more on Fri, especially in Atlantic Counties.

I wonder will Sat see some Lightning activity ( possibly the South of the country ?) Forecast to be heavy and persistent for a time on Sat morning and to clear Northwards.

Ferocious forecast for the Mediterranean ... http://www.estofex.org/