Nick F

IDO The EC op doesn't look like an outlier to me on wetterzentrale spread for Birmingham, would treat those meteociel EPS spread graphs with caution, think they are too crude.

EPS mslp mean has the late week / early Saturday low running through the Channel! Trend GIF over last 4 runs shows the slowing of the low moving NE/E and also further south track. Ending up in France?

A blog looking at how the current mild weather lasts into the first half of next week but then gets replaced by colder air later in the week, with an increasing risk of snow in places. View the full blog here

Stunning sunset out my office window near Heathrow Airport earlier

Today provisionally saw the warmest January temperature on record in the UK, with 19.6C in Kinlochewe in the NW Highlands. It's been rather mild this past week, but will we see colder weather return in February? View the full blog here

Synoptic analysis looking at the arrival of Sahara dust and very mild air from the south over the weekend and into the start of next week. Maybe an idea not to wash your car for now! But could be some nice sunsets or sunrises. View the full blog here

Grid values for UKV at 3am, can see why they issued a red wind warning

A synoptic analysis looking at the development and impacts of Storm Isha arriving Sunday night and expected to bring widespread gales with potential for disruption. View the full blog here

None of the extended clusters showing Atlantic troughing / upper flow energy undercutting high pressure building north over Europe that would hold a Scandi high in place for a sustained enough period to bring cold air our way though, so the high would eventually collapse. My worry is the lack of low heights especially over Iberia from Atlantic troughing undercutting, as well as further east over the Mediterranean Basin from undercutting of cold air from the NE, will mean we end up with a large Scandi-Euro High of little benefit to coldies in the UK other than some surface cold perhaps. But, we know these clusters can change, so more runs needed. But I'd feel much happier if we saw troughing extending from the Atlantic over Iberia rather than the semi-permanent Azores ridging there. Extremely dry across parts of southern and eastern Spain this winter so far, due to lack troughing extending from the Atlantic over Iberia with ridging dominating. We can get away with cold air undercutting high pressure over Scandinavia from the NE into southern Europe to lower heights over the central Med to bring a brief cold easterly, but prefer of the Atlantic troughing undercuts too to make it more sustained. Original post: https://community.netweather.tv/topic/99793-model-output-discussion-cold-spell-ending-what-next/?do=findComment&comment=5018826

I don't spend all day everyday doing it, weather forecasting is part-time work for Netweather, though also tweet a fair bit, wish I had more time to post on here but work life and home life gets in the way. I have a main job besides doing the Netweather articles. And it ain't weather forecasting I'm afraid. Back to the models, as John H mentions, the UK isn't consistently bathed in Tm air for the next 10 days - alternating rPm and Tm air, but when we are in Tm, it could be very mild, like this Tuesday coming - with 14-15C on the cards, but Wednesday in rPm air and cooler

True, the lack of cold from antecedent mild southwesterlies pumping deep into NE Europe and NW Russia is a worry, though with the right synoptic pattern developing, it can return there from the arctic fairly quickly before the rest of northern Europe can tap into it, but without the notably low temperatures we have seen build since November over Scandinavia, will any quickly developing cold pool be too marginal by the time it reaches here? All conjecture for now, as we have to get a Scandi high to develop and get and easterly flow far enough west in the first place. Getting all the right pieces of the jigsaw to fall into place, not least getting cold air back to the NE and E Europe, a Scandi high to extend far enough west and crucially low heights over southern Europe to stop a high to the NE collapsing south, is an uphill battle to break out of the strong +NAO pattern ensuing.

No signs of any deep cold from the 00z EPS yet ... long road back to cold and snow for now. Need patience of a saint in the UK if you've not seen lying snow yet this winter. Because it can get to you if you spend too much time over analysing and discussing the models each day, why I try to find other things to take my mind away from the disappointment of not seeing snow from this cold spell and seeing little on the horizon. Otherwise you just get frustrated.

None of the extended clusters showing Atlantic troughing / upper flow energy undercutting high pressure building north over Europe that would hold a Scandi high in place for a sustained enough period to bring cold air our way though, so the high would eventually collapse. My worry is the lack of low heights especially over Iberia from Atlantic troughing undercutting, as well as further east over the Mediterranean Basin from undercutting of cold air from the NE, will mean we end up with a large Scandi-Euro High of little benefit to coldies in the UK other than some surface cold perhaps. But, we know these clusters can change, so more runs needed. But I'd feel much happier if we saw troughing extending from the Atlantic over Iberia rather than the semi-permanent Azores ridging there. Extremely dry across parts of southern and eastern Spain this winter so far, due to lack troughing extending from the Atlantic over Iberia with ridging dominating. We can get away with cold air undercutting high pressure over Scandinavia from the NE into southern Europe to lower heights over the central Med to bring a brief cold easterly, but prefer of the Atlantic troughing undercuts too to make it more sustained.

A Sudden Stratospheric Warming (SSW) took place on Wednesday, with a reversal of zonal winds at 10 hPa 60N, but it was a brief reversal and zonal winds look to return in the polar stratosphere, marking its recovery. So its likely this SSW won't trigger high latitude blocking and bring prolonged cold and wintry weather. View the full blog here

There is a chance, as GEM shows, that the Atlantic upper troughing / surface lows disrupt more and slide SE against the cold airmass over the UK weekend of 20/21st. UKMO looks like it could head down that route too after t+168. Not a great deal of support from GEFS postage stamps. But still time for changes towards Atlantic trough disruption. But the return of westerlies weekend of 20/21 looks more favoured for now. Snow event looking likely for parts of Scotland and perhaps N England on Tuesday, as that low that forms south of Iceland in the arctic flow tracks SE towards northern Britain. Also snow showers for far north and coasts exposed to the N or NW Flow. EC has snow event back on the menu for S England Weds/Thurs next week, GFS a near miss, UKMO and GEM well south over France. Could be more back and forth on this front, though suspect it will end up south of S England. Cold all next week, but away from the north, can't see a great deal to get excited about if you want snow, unless the low off the Atlantic tracks further north than suggested. I see the 'but features can pop up at short notice' comments, but nothing to suggest anything popping up other than the Channel low threat for now.

No point squabbling over how dry it will be, too far away to pin down where troughs, convergence zones or lows will track next week that may bring snow I think the key to the longevity of next weeks cold spell will be how long the TPVs over Canada and N/NE Europe are kept apart by ridging mid-N Atlantic and Greenland. GFS/GEM ops are more bullish to merge to 2 TPVs over the Atlantic later next week, turning the flow more zonal / milder / unsettled. While EC det keeps the two upper vortices apart. However, as already posted, the mean of both GEFS and EPS do join the two together by day 10, with the more zonal look taking over. But the smoothed out mean may not be the best guidance at handling upstream developments and how the upper flow and surface lows over the Atlantic interacts with the cold air entrenched over northern Europe Original post: https://community.netweather.tv/topic/99760-model-output-discussion-colder-but-how-cold-and-for-how-long/?do=findComment&comment=5006538

Looking at the extended EPS spread, the 00z det was on the cold side later on but by no means without support, the TWO and meteociel graph makes it look like an outlier, but it's not really on the wetterzentrale spread. The mean does rise though towards day 10 and after, so we have to assume, for now, that it will turn milder after next week for a time, as the Canadian and north European TPV lobes merge to cover the far N Atlantic in low heights driving a more westerly flow. This ties in with background larger scale teleconnections e.g. MJO motoring through 'warmer' phases at decent amplitude. Still a decent spike in precipitation for Weds 17th on London EPS, so still suggest a good chance of precip and likely snow with the T850 mean below 0C, in 1st chart posted above. Original post: https://community.netweather.tv/topic/99760-model-output-discussion-colder-but-how-cold-and-for-how-long/?do=findComment&comment=5006604

00z UKMO 'current laying snow' chart animated through next week until Thursday suggests northern areas look to see greatest chance of laying snow, probably from that low that forms near Iceland and drops SE and also from showers, but also a chance in the southeast as one or two lows track east close to the south. Although it's too far off to forecast snow for now, seems a reasonable assumption, for now, to think Scotland, N England and N Ireland stand to see greatest chance of snow, lower chances further south, unless the Atlantic lows track further north, but the low from the southwest more likely ending up further south into France. Original post: https://community.netweather.tv/topic/99760-model-output-discussion-colder-but-how-cold-and-for-how-long/?do=findComment&comment=5006567

Looking at the extended EPS spread, the 00z det was on the cold side later on but by no means without support, the TWO and meteociel graph makes it look like an outlier, but it's not really on the wetterzentrale spread. The mean does rise though towards day 10 and after, so we have to assume, for now, that it will turn milder after next week for a time, as the Canadian and north European TPV lobes merge to cover the far N Atlantic in low heights driving a more westerly flow. This ties in with background larger scale teleconnections e.g. MJO motoring through 'warmer' phases at decent amplitude. Still a decent spike in precipitation for Weds 17th on London EPS, so still suggest a good chance of precip and likely snow with the T850 mean below 0C, in 1st chart posted above.

00z UKMO 'current laying snow' chart animated through next week until Thursday suggests northern areas look to see greatest chance of laying snow, probably from that low that forms near Iceland and drops SE and also from showers, but also a chance in the southeast as one or two lows track east close to the south. Although it's too far off to forecast snow for now, seems a reasonable assumption, for now, to think Scotland, N England and N Ireland stand to see greatest chance of snow, lower chances further south, unless the Atlantic lows track further north, but the low from the southwest more likely ending up further south into France.

No point squabbling over how dry it will be, too far away to pin down where troughs, convergence zones or lows will track next week that may bring snow I think the key to the longevity of next weeks cold spell will be how long the TPVs over Canada and N/NE Europe are kept apart by ridging mid-N Atlantic and Greenland. GFS/GEM ops are more bullish to merge to 2 TPVs over the Atlantic later next week, turning the flow more zonal / milder / unsettled. While EC det keeps the two upper vortices apart. However, as already posted, the mean of both GEFS and EPS do join the two together by day 10, with the more zonal look taking over. But the smoothed out mean may not be the best guidance at handling upstream developments and how the upper flow and surface lows over the Atlantic interacts with the cold air entrenched over northern Europe

Morning. Great EC det this morning, cold throughout and ends with a cold high. Snow event for central Scotland on Tuesday as that secondary low that develops in the polar flow near Iceland drops southeast. Then another potential snow event across the far south mid-week, as an Atlantic low tracks east, but still uncertainty over its track for now. UKMO looks really good too up to Thursday, looks like a cold NE flow developing after then. GFS looks rather too bullish to turn it mobile, unsettled and milder off the Atlantic. GEM looks like it goes down a similar turning mobile / milder route to GFS Stick with the Euros IMO. Original post: https://community.netweather.tv/topic/99760-model-output-discussion-colder-but-how-cold-and-for-how-long/?do=findComment&comment=5006453

Potential for 2 lows tracking east close to southern Britain Weds and Thurs/Fri, but they may end up tracking further south into France on current trends, so could end up dry for much of next week for England and Wales, though Scotland, N. Ireland and N England could see a snow event early week plus snow showers in the north and coasts.

Morning. Great EC det this morning, cold throughout and ends with a cold high. Snow event for central Scotland on Tuesday as that secondary low that develops in the polar flow near Iceland drops southeast. Then another potential snow event across the far south mid-week, as an Atlantic low tracks east, but still uncertainty over its track for now. UKMO looks really good too up to Thursday, looks like a cold NE flow developing after then. GFS looks rather too bullish to turn it mobile, unsettled and milder off the Atlantic. GEM looks like it goes down a similar turning mobile / milder route to GFS Stick with the Euros IMO.

The difference between GFS vs UKMO and ICON are quite stark at t+144, so probably not worth fretting over mild vs cold boundary snow events next week at the moment. Best not over analysing beyond 6 days IMO. T+144 GFS T+144 UKMO and ICON UKMO and ICON similar in having the straight northerly that digs further south, a stronger mid-Atlantic ridge north and east of the Azores low, which is kept more at bay and thus doesn't phase with the N / NE European trough. Not sure who my money's on until the EC comes out though ... but suspect GFS maybe a tad too progressive with upper flow energy over the N Atlantic, particularly as it's pretty much a cut off low near the Azores that tend to be a sign of a weakening jet that disrupts. 12z GEM does follow a similar route to GFS, which makes me a little nervous to call UKMO and ICON more likely correct for now, but could it be the great N American wx models vs European wx models battle this evening? Original post: https://community.netweather.tv/topic/99706-model-output-discussion-into-2024/?do=findComment&comment=5003476