South East & East Anglia Regional Discussion 8th June 2013 onwards

[Tom Montalbano]

 

Hi Tomas - yes, from our pov the GFS is not good at all for Monday and then again on Weds and Thurs. I checked the ECM and that is also a horror story all the way from Monday to Thursday:nonono:  The long escape enjoyed since 2010 (IMBY) looks like it might finally be coming to an end:( Time to forget about this, get the dinner and have some wine I think:)

Ah Tams but nobody expects The Spanish Plume, its main weapon is humidity.........and high temps, amongst its weaponry are such diverse elements as etc, etc......Oh dear, phobic mania already setting in!Tom.

[Biggin]

So are we on track for some heavy rain or even better bout 3 ish??

[john pike]

hi biggin

 

from 3am on there is some unstable air and some lively

 

heavy rain coming in

 

not sure how thundery but the risk is there

 

sorry tom

[Biggin]

hi biggin

 

from 3am on there is some unstable air and some lively

 

heavy rain coming in

 

not sure how thundery but the risk is there

 

sorry tom

Ta John we prob about 5 miles apart give me a shout

[john pike]

hi biggin

 

will do

 

i like the look of monday

 

 

 

could get lively

 

[Biggin]

Willitrain showing showers over me..... naf all

[john pike]

fax charts at present

 

tomorrow

 

a bit gusty on a westerly flow

 

showers look to be mainly the far north of the region

 

the snag on this chart is the trough to our west

 

it should weaken as it moves east to north east but may effect the north of the region for a while

 

other than that should stay dry and sunny

 

temps around 18

 

 

 

tomorrow night

 

that looks dry

 

and quite warm

 

sunday

 

a very weak southerly flow

 

looks mainly dry and sunny

 

just a watch for the very far southern regions of the trough in the north sea

 

it possibly might send a few showers and create cloud cover

 

i think it should stay dry though

 

temps around 18-20 should feel warm in the sun

 

monday as explained above

 

temps should reach 22 or above but will feel humid

 

stormy??

 

westerly flow and could get quite gusty

 

update the rest later

 

ukmo at present certainly looks warmer and potentially stormy

[Bluebreezer54]

Hi JP. Any thoughts about tonights potential ??

[Norfolk Sheep]

 Ah Tams but nobody expects The Spanish Plume, its main weapon is humidity.........and high temps, amongst its weaponry are such diverse elements as etc, etc......Oh dear, phobic mania already setting in!Tom.

I'll be pulling up a comfy chair by the window then hehe!

Lovely day here, spent most of the afternoon turfing out the garden furniture storage shed, removing a couple of broken panes, washing cushion covers etc. Very productive! Only problem was when the sun was out it was shorts and t shirt, when it went in it was find the joggers and jumper and put either/both back on!

[Tom Jarvis]

What time are we expecting the front to pass through Sussex Jp ??

[john pike]

Hi JP. Any thoughts about tonights potential ??

 

hi bb

 

the set up is a cold front colliding with warmer air around 2-3am onwards

 

some pretty heavy rain showing which should spark off some storms

 

the only downside is to me it hasn't quite had the chance to get warm enough yet

 

better chance next week for that

 

so all i can really say is expect the odd rumble or 2 very late tonight

 

with some pretty high rainfall totals overnight as well

 

gonna be a very late one to watch this unfold

 

[john pike]

gfs giving us some cape to work with but not a huge amount on offer

 

will be a look out the window jobbie to be sure

 

i reckon i will be asleep by then

[Ben_Cambs]

Hello all,

 

Well finally I've finished my exams! A great sense of relief, especially after I put a lot of time into preparing for my last exam!

 

It's been about a week since I lasted posted, but the weather in the past week has been poor it has to be said! Cool, gloomy conditions and in recent days a really brisk wind for the time of year, creating a mess in the garden! Disappointing after a pleasant and sunny start to summer.

 

Despite the cool conditions, I don't think it has rained for a couple of weeks of least and the grass is beginning to look very dry and brown, though the wind of recent days will of dried the grass out even further, so could do with some rain to freshen things up a bit (and some more sunshine!)

 

Reading over the potential thunder risk tonight, it got me thinking about the lack of storm activity so far this year, I know we aren't too far into what is regarded as the storm season, but usually we would have had at least one or two thunderstorms by now. The past 6-7 years haven't been too overwhelming for thunder activity, compared to the years before, a trend perhaps.

 

It does look like we will see some rain over the next few days, and a much lighter wind after tomorrow, which should make it feel a lot more pleasant. May very briefly turn quite warm during the middle of the coming week.

 

Hope you all have a great weekend!

[john pike]

 

gfs certainly showing a vast warm up next week

 

cannot trust these as they keeping changing like our weather

[Bluebreezer54]

I'll pass the time for now by watching Micky Flannagan on Channel 4......I'm double busy !!

[Keraunic]

Something about. I'm very chatty. I wouldn't mind but I'm alone In the house.

I'm banking on tomorrow's potential. Here's hoping.

Night night each and....good luck.

[Tom Jarvis]

Storm Forecast

Valid: Sat 15 Jun 2013 06:00 to Sun 16 Jun 2013 06:00 UTC

Issued: Fri 14 Jun 2013 22:16

Forecaster: TUSCHY

A level 1 was issued for C-UK mainly for an isolated tornado and scattered strong to isolated severe wind gust risk.

A level 1 was issued for far N-Germany and Denmark mainly for an isolated tornado and scattered strong to isolated severe wind gust risk.

A level 1 was issued for extreme NE Bulgaria into C-Ukraine and adjacent areas into Russia mainly for a few large hail and severe downburst events.

SYNOPSIS

A robust low with strong thermal anomalies especially at mid/upper levels advances east and crosses Ireland/UK during the forecast from west to east. An unseasonably intense wind field along its southern fringe spreads east and pulls the complete feature all the way to the North Sea until Sunday 06Z. It's not common to see such an healthy and progressive feature during June but luckily its wind field does not overspread any serious CAPE plumes over NW/N Europe.

Eastwards building westerlies with that feature assure height rises over the W/C Mediterranean with mostly stable conditions. A broad but ill defined upper trough over SE Europe lifts slowly to the N/NE during the forecast, so most of SE/E Europe will see another round of active thunderstorm development.

At the surface, an extensive W-E aligned boundary becomes reinforced by a SE-ward moving cold front from France...at least its western fringe. This boundary will be the focus for isolated to scattered CI.

DISCUSSION

... Parts of UK ...

A severe risk could arise for a few hours during the afternoon due to perfect matching of modest (300-600 J/kg) SBCAPE, strong shear and some forcing. A plume of wrap-around moisture spreads east and covers parts of C-UK during peak time heating. Mid-level lapse rates remain steep due to cold mid-levels and with some temporal diabatic heating expected, SBCAPE build-up of 600 J/kg looks reasonable for a confined region. A weak impulse, embedded in this brisk westerly flow regime, crosses the area at the same time and inserts enough lift for isolated to scattered CI. DLS rapidly increases from N to S from 20 to 35 m/s and LL shear peaks at 10-15 m/s. Forecast soundings reveal mainly straight wind fields and therefore quite unidirectional hodographs. However, incoming impulse/wave also induces some slight backing of the LL winds, so directional shear in the lowest 1000 m should increase to 100-200 m^2/s^2. Also, with expected shear in mind, splitting storms may occur with deviant storm motions also increasing helical inflow. LCLs remain at or below 800 m, so there is a risk for an isolated tornado event. Beside that, downward mixing of 20 m/s at 850 hPa may also produce a few strong to severe wind gusts next to an isolated large hail risk. The main thunderstorm risk will be confined to the 12-18 Z time frame. Beyond sunset, thunderstorms rapidly weaken while moving offshore.

... The Netherlands, NW Germany and Denmark ...

A wave rotates rapidly around the main cyclonic vortex over UK and acquires a negative tilt. This trough spreads rapidly east and causes a strongly diffluent mid/upper flow pattern to overspread the area of interest during the daytime hours from the Netherlands to the E/NE. Such a pattern is not favorable for healthy and compact UVV maxima and current data also points to a gradual weakening of the forcing. Some better BL moisture becomes advected into the NE-ward shifting trough/wave and a pool of marginally more favorable mid-level lapse rates crosses the region .. with N-Germany/Denmark probably being affected during peak heating. Also with such patterns, mid-level cooling won't play any serious role until the wave exits to the north with better/depper CAA expected by then. Hence, EL temperatures remain quite warm and if DMC can evolve is still a bit unclear. The risk however increases from south (N-Germany and the Netherlands) to north (Denmark). We issued a 50-% lightning area, where DMC is expected right now.

Ingredients-wise, strongest flow starts above 700 hPa, where convection might already top out, so how much effective DLS will become available is difficult to pinpoint. However, any stronger and longer lived convection will evolve in an environment, featured by 300-700 J/kg SBCAPE (increasing to the north), 15-20 m/s DLS and veering profiles. Marginal hail and strong wind gusts will be the main hazard. In addition I don't want to rule out an isolated tornado event mainly in the level 1 area with low LCLs and better shear. In fact the upgrade to a level 1 was performed due to forecast soundings along the German/Danish border, which show some curvature in the lowest 3 km, strong speed shear, veering in excess of 45° between LL and mid-levels in addition to 400-500 J/kg CAPE. The risk rapidly vanishes after sunset.

... S-France to the Alpine region to W-Ukraine ...

The frontal boundary will be the focus for at least isolated CI. Numerous weak mid-level impulses cross that boundary during the forecast and they, combined with the rough orography, should overcome mainly weak capping. Yesterday's sounding from S-France to Austria already featured ill mid-level lapse rates due to deep WAA from 700 hPa upwards. Lapse rates increase somewhat towards the W-Ukraine but still remain marginal. Local BL dewpoints in the mid tens with averaged BL mixing ratios exceeding 10 g/kg (on a regional scale) could offset those negative effects of the lapse rates. Hence, numerous patches with 300-800 J/kg MLCAPE probably evolve. CI over S-France into Switzerland will be questionable due to very weak dynamics but most models show at least some very isolated initiation and we therefore issued a 15-% lightning area. Confidence in initiation increases somewhat from E-Switzerland towards Austria due to the passage of a weak impulse during the late afternoon and evening hours from W to E. We issued a 50-% lightning area, where initiation looks most likely and a few strong to temporarily severe storms might evolve as DLS increases to at or above 15 m/s with higher 1-8 km shear expected. Isolated large hail and strong wind gusts are forecast with those storms which rapidly decay after sunset.

Similar confidence in CI and expected severe probabilities exists further east over Slovakia into W-Ukraine.

... Bulgaria to C-Ukraine into parts of W-Russia ...

A weakening frontal boundary enters the forecast area and is expected to dissolve until 06Z. Nevertheless, some moisture pooling along that convergence boundary occurs beneath moderately steepened lapse rates. Hence, 800 - 1500 J/kg MLCAPE likely evolve with virtually no shear present at all levels. Numerous intense pulsating storms likely pose a large hail and severe downburst risk before upscale growth into numerous ill defined clusters is forecast. Somewhat stronger convergence with higher effective PWs are forecast from the C-Ukraine to the N/NE. Slow moving or training storms might pose a flash flood risk in those areas due to heavy rainfall amounts, but neither the moisture nor the strength of convergence nor the strength of the inflow look healthy enough to expect any serious flood concerns. However the strongest storm clusters evolve from the C-Ukraine to the N/NE with more ill defined clusters further to the south into Bulgaria. Especially along the boundary, storms continue well into the night with a deacreasing severe risk.

http://forum.netweather.tv/index.php?app=core&module=attach&section=attach&attach_rel_module=post&attach_id=174339

From convective storm thread

Edited June 14, 2013 by Tom Jarvis

[john pike]

 

ukmo

 

 

wednesday

 

 

ukmo

 

 

tuesday looks more stormy

 

wednesday looks nicer for now

 

ukmo at 144

 

that looks potentially stormy as well

 

lots of fun next week looking at these

 

more tomorrow

 

goodnight

[NO LONGER POSTING]

I dont think this year has been bad at all for storms so far.. I have had 3 thunderstorms 1 very good the other 2 only couple of rumbles..

[NO LONGER POSTING]

POSSIBLE SERVER WEATHER SOUTH EAST UK WEEK COMMENCING 17/06/2013

 

Tropical storm Andrea has now become absorbed into the Mid Atlantic flow and the remnants of tropical air will become mixed and advected torwards Southern Ireland by Sunday PM and Monday. The tropical or sub tropical ingestion is expected to lead to marked cyclogenisis South of Southern Ireland by Monday, which is then expected to oscillate across the Bay of Biscay. The placement of this feature will be fundamental in determining the eventual development of instability and CAPE, and there will be and has been significant fluctuations in CAPE across the GM frame-work.

We're watching Monday through into much of next week very carefully, the movement of this low will be critical and is going to lead to some severe weather episodes across Western Europe next week. It also have the potential to encourage a strengthening warm air advection process from the South and propagate any plume that develops across France, towards our shores. There is high uncertainty on precise development, but the strongest overall signal has been towards South East England.

It's definitely worth monitoring! Here are a few updates that I have been issuing on MetWeatherUK on Facebook.

Update 1

ECM rather interestingly develops the low around Biscay and Iberia for the same time-frame. What is even more interesting, is the continued forecast for remnants of tropical storm Andrea to be embedded within the flow around this period. GM is likely responding to this tropical or sub-tropical ingestion. Whether both the Global and European frame-works are both having difficulty with this dynamic, is still open to question. Very interesting potential though. The tropical air appears to lead to the development of unseasonably strong cyclogenisis, and it's one I'm definitely watching closely.

Update 2

We still have tropical remnants induced cyclogenisis occurring across Biscay at the time-frame T+90>, still various uncertainties on the timing and trajectory this feature will take, as a result we can expect to see significant variability in the CAPE forecast for next week. Either way, I think it's likely to provide us with some instability, but to what extent? Latest ECM and GM favours SE England for periphery plume engagement, and prior to this, a build up of CAPE across Southern Britain. Pinch of salt on this at the moment. This low, continues to need close watching and will provide ideal conditions for a severe weather outbreak for some parts of Europe.

Update 3

A classic example of the large variability in CAPE indices across various model runs can be seen on the latest GFS 06Z guidance. Large numbers showing again. It's all about what this troublesome sub tropical low decides to do, but either way its getting my attention.

 

Happy Days? Not my information..

[john pike]

 

18z 

[ZONE 51]

Very gusty conditions developing now with the rain. Also through Saturday very windy weather possible.

Here is a recent radar image from  - http://www.weatheronline.co.uk/

 

 

Heavy band of rainfall moving in from the west now crossing the SE/EA over the next few hours.

----

Through the afternoon winds becoming very gusty again, the image below shows the tight isobars across the SE particularly,

 

 

 

--

Next week's image may come as a surprise to many..

 

that is quite something for this time the year!

The charts are NAE

Edited June 15, 2013 by ElectricSnowStorm

[NO LONGER POSTING]

Very intense rain!!! Moonsooooon!! Clear sky's following sun just just illuminateing the horizon light blue

[Keraunic]

Mornin each. 04:50 very heavy rain and strong wind. But no thunder. Just slowing down a little now.

[Charltonkerry]

We certainly had rain last night, as its all wet outside (and they say I am not technical), its a beautiful sunny morning, one of those glorious ones, the sun is bright, a few wispy clouds scudding across the sky, with the occassional gust of wind. Looks lovely and its Saturday.