GaWx

From the 18Z Euro, the peak 500 mb hts over southern England are near 592 dm at 12Z on 7/18/22: This is ~21 dm above the normal of ~571 dm: The peak 850 mb temp anomaly on the 18Z Euro over S. England is +15C to +16C (+27 to +29F) at 3Z on 7/19/22: The peak 2M temperature on the 0Z GFS at London is ~+38C/+100F as of 12z on 7/19/22 but the hottest would likely be near 15Z, which I don't have. The hottest on the 0Z GFS in S England at 12Z on 7/19/22 is near +40C/+104 F, but a 15Z map would likely be hotter. (I'm not familiar with what the GFS 2m temp bias is here.) These 2m temp anomalies are +28 to +30F: The all-time hottest daily low at London is +23.3C or 73.9F, set 7/29/1948. This has a good chance to be beaten on Tue 7/19/22 but we'll have to see if the temp drops back below that before midnight Wednesday: https://en.wikipedia.org/wiki/Climate_of_London This UK heat originated over N Africa and then traveled north to Spain with very little modification from the Mediterranean Sea due to traversing only a narrow portion of it. It will peak in W and N France on 7/18 before peaking in England on 7/19 on steady SSE winds meaning little modification from the English Channel. A surface low to the west of in combination with a surface high to the east is causing this hot wind flow. AGW is likely contributing several degrees to this heat. In other words, without AGW, the same setup would likely result in the peak heat being several degrees cooler than what will occur. I'd love to see the maps for similar intense historic heatwaves to compare things like peak 500 mb hts, 850 mb temps, and surface features. I assume the setups would be similar.

1. She/he has been bearish for the US east coast since almost as far back as the inception of the web lol. 2. With three NS as of July 17th, 2022 has been a hair more active vs the average # of NS as of July 17th in non-El Nino seasons back to 1995, which is 2.7. 3. The # of NS through July 17th for non-Nino seasons back to 1995 has had virtually no predictive power for the remainder of the season. That number of post July 17th storms has averaged 14.1 NS for non-Nino seasons back to 1995, whether active or not through July 17th. 3. After very recently analyzing some data for 3rd year La Niña seasons and comparing them to the prior season (2nd year La Niña), I've decided to lean against a hyperactive 2022. An active season that's more active than the non-Nino season average since 1995? Quite possibly. But hyperactive? I don't think so at this point. More active than 2021's active 146 ACE? While a reasonable possibility as hyperactive is quite a bit above that, I'm currently leaning to ACE not reaching 146. Edit: 4. Based on the same data, I feel that the Gulf coast of FL is at an above normal risk the season.

Thanks for posting. Indeed, this graph clearly shows what I had posted about regarding the slight cooling in summer despite strong warming Sept-April, with strongest warming Jan-Feb.

For the first day in over two months, the averaged Arctic 2m temperature north of 80N (red line) on July 16th went (barely) warmer than the 1958-2002 average (green line). It is ~35 F after being barely above 32 F on July 4th. The average between those two dates only barely rises. This is only one factor of many but it will be interesting to see if melting has started to turn around and increase vs the 2007-2021 average melt over the last few days since the last ORH update, which was done as of July 12th: melt

My last 3 days (7/14-16) of rainfall: 0.03", none, none but heavy nighttime thunderstorms along and offshore the immediate coast moving northerly very early AM produced lots of rumbling thunder and frequent lightning in the eastern sky for several hours 10.73" is my total 7/1-16, one of the heaviest ever for the first half of July and ~triple the normal! Normal for the ENTIRE month is ~7". I'm at 17.73" since June 1st.

Thank you for the detailed reply. I'll need to think through that some more to make sure I understand it. Regarding the line that I quoted from you, would that negative feedback (colder higher latitudes with climate change) eventually result in cooling the lower latitudes back down or at least slow or even stop the warming there? In other words, is GW self-limiting/does it have a ceiling because of this? If so, where is that ceiling?

Thanks for those links. From your 2nd link, I found this interesting graph of Arctic 2m temps N of 80N by decade: 1. Temps warm as one would expect due to GW from the 1960s (dark blue) to the 2010s (red) September-April with the winter having the most intense warming, especially JF. 2. I estimate JF to be a whopping 7C (13F) warmer in the 2010s vs the 1960s (-24C vs -31C). 3. It appears to still be warming steadily Sept-April. In JF, the 2010s are 3C (5F) warmer than the 2000s (-24C vs -27C). 4. The summers, which have much smaller variance (so one will need to look carefully to see this), have oddly enough done the reverse with the 1960s the warmest and the 2010s the coldest for late May through mid-August with the 2010s ~1 F colder than the 1960s. Does less sea ice mean slightly colder in summer? If so, why? Edit: I found this: "When ice melts or water evaporates, energy must be taken from the environment in order for the ice or liquid to move to a less ordered state. Energy is needed to weaken the individual hydrogen bonds between H20 molecules. When water (in any of the three phrases) moves from a higher to a lower ordered state, the air surrounding the H20 will have heat subtracted from it. The three processes that subtract heat from the surrounding air are evaporation, melting and sublimation (solid to gas)." https://www.theweatherprediction.com/habyhints/19/ So, is it because the summers have had increased amounts of melting which then cools the surrounding air more than if there were less melting?? 5. 2022 has been relatively cold since late April on most days after a relatively very warm winter as has been noted ITT. The summer of 2022 has averaged nearly 1C/2F colder than the 1960s. Perhaps that has been helping to slow the melt?

After 6 straight days of measurable rain giving me a total of 6.7", I got none today although there was thunder from a nearby storm.

Hmmm, I must have done something wrong considering how knowledgeable and experienced you are on this, but I can't figure it out yet after looking at it again carefully. Am I doing an apples to oranges comparison? I thought you were looking at "Arctic sea ice area" in sq km. Is the source I used not looking at the same thing? Does it use a different method to measure area? Fwiw, its graph (see below) shows 2009, 2010, 2013 (highest since 2007 with 4.6 msk), 2014, and 2021 all above 4 million square km. It even says this about 2021: "In 2021, the Arctic minimum sea ice covered an area of 4.13 million square kilometers (1.6 million square miles)." Would you please provide a link to your source for annual Arctic minimum area as well as how current sea ice area compares to prior years for the same date? What do you have for 2012's minimum? This has ~2.9 million sq km: https://svs.gsfc.nasa.gov/5002

Last season had two Mid-Atlantic/NE US TS landfalls, the first season since way back in 1985 (Gloria and Henri). Before that, you had to go back to 1971 (Doria and Heidi). Others before that in that area with 2 TS+ landfalls in one season: 1961 (Esther and unnamed), 1960 (Brenda and Donna), and 1954 (Carol and Edna). So, 37 years since the last one and only an average of one every 14 years for two landfalls since 1950. Since 1950, only a little over 1/3 of seasons had at least one TS+ landfall. Thus, I still think you're downplaying 2021 a bit too much. You already called it weak and tame in other posts. You're making it sound like it was so quiet.

Yeah, I realized that when I posted though it certainly can get confusing. I said: "But it does appear that the chance of it being at or above the 2007-21 average minimum of 3.9 msk has increased quite a bit vs how it looked on June 29th. Along with this, it appears that the chance for a September SIE at or above 4.8 msk has increased. That compares to the rough average Sept. extent of 4.7 msk for 2007-21 based on the Sept. SIE graph that @bluewaveshowed Monday." So, I first referred to an increased chance for the minimum area to be 3.9+ msk (at or above the 2007-21 average minimum area). Then I referred to an increased chance for the September extent (SIE) to be 4.8+ msk (near or above the 2007-21 average minimum extent).

Based on these numbers, the last two days have continued the significant increase based on the date of 2022 area vs the 2007-21 average area that started ~6/29. As of 7/12, the 2022 area was +370K vs the 2007-21 average. This is a 510K increase vs the 2007-21 average just since June 29th (see table below). Based on the graph at the bottom of this post of the minimum area for 2007-21, I roughly estimate an average minimum area for 2007-21 of 3.9 msk. The range in msk is roughly 2.9 to 4.6. If the +370K vs 2007-21 average were to still be the case when the 2022 minimum is hit, that would mean a 2022 minimum area of ~4.3 msk. If that were to occur, that would mean a minimum higher than all years 2007-21 except for 2009, 2013, and 2014. However, having a +370K vs 2007-21 at the minimum of the year is very optimistic, especially considering the near record low multiyear ice levels as of last September that @bluewaveposted about yesterday. So, average ice thickness was then at near record lows. Thus, I think that the chance of this year's minimum being significantly lower than 4.3 msk is high. But it does appear that the chance of it being at or above the 2007-21 average minimum of 3.9 msk has increased quite a bit vs how it looked on June 29th. Along with this, it appears that the chance for a September SIE at or above 4.8 msk has increased. That compares to the rough average Sept. extent of 4.7 msk for 2007-21 based on the Sept. SIE graph that @bluewaveshowed Monday. Recap of current area vs avg. of last 15 years as of: 6/15/22: +70K 6/16/22: +120K 6/20/22: +240K 6/22/22: +140K 6/29/22: -140K 7/1/22: +70K 7/10/22: +250K 7/12/22: +370K Graph of Arctic annual ice area minimum since late 1970s from https://svs.gsfc.nasa.gov/5002

Like clockwork, the late day thunderstorm is hitting. The CTG is pretty significant. Update: However, for a change we're getting a needed break from the prior days of heavy rain (nearly 11" in 11 days) with just a steady gentle rain along with rumbles of thunder now. I ended up with only 0.05", which brings MBY mtd to 10.70". Based on my look at official Savannah records back to the 1870s as well as the ag station records, this 10.70" could easily be and probably is the heaviest for my location for July 1st through 12th.

Yesterday's (7/11) rainfall in Chatham County, GA, ended up being the most widespread very heavy in the county overall since 11/6/2021 (though MBY's heaviest was 7/1) and thus continued the VERY wet July in much of the county, especially in a good portion of central to eastern sections. I ended up at 2.95", bringing my July MTD up all of the way to a whopping 10.65"! For MBY, this has to be one of the wettest 7/1-11 periods ever with nearly 1"/day averaged out! Here is the CoCoRaHS map that covers yesterday's rainfall, which was heaviest (orange and red) from Coffee Bluff/White Bluff eastward to Burnside and Skidaway Islands (3-4.75"). KSAV got 1.07" while KSVN (Hunter) got 2.46":

This afternoon and evening I've gotten another boatload of rain from thunderstorms with street flooding at least about as bad as yesterday and it is still coming down. I've received 2.05" since mid afternoon so far, which puts me at 9.75" MTD and counting. That is already near 4 times the normal for July1-11 and is way, way higher than what KSAV has received. That is mainly because I got 4" on 7/1 from the predecessor to TS Colin as well as 2" yesterday and 2.05" so far today whereas the airport only got light all three days. Today looks more widespread than yesterday in the county with the heavy rainfall from what the radar has been showing although the airport has received only light so far as I said. Edit: I ended up at 2.95" total yesterday (7/11) with thunderstorms almost continuous from mid-afternoon through well into the evening.

It is nothing new that the operational GFS has a bias to overdo summer highs during hot periods. Also, the Euro op. has done that at least to some extent the past few years. The better bet is to go with the ensemble means because they average cooler than the operationals.

I ended up right at 2" yesterday (7/10), near the jackpot for the county. To illustrate the high variability yesterday in Chatham County, check out the image below, which is the 24 hour rainfall ending at 7AM this morning per CoCoRaHS. The lows in light blue of 0.05" and 0.06" were at opposite ends of the county, Garden City and Skidaway Island. The highs in orange and red of 1.39" and 2.11" were in a narrow ~5 mile long corridor within the heart of the county from near Wilshire Estates on the southside (near Abercorn) to near E. Victory Dr.:

Today's weekly update has Nino 3.4 at -0.5 C, slightly warmer than the prior week's -0.6 C. For those who don't happen to know, the -0.5 C is essentially based on the average of last week due to the normal ~5 day reporting lag. The SOI, after one day of barely negative, has gone back to positive (modest so far). I'm assuming that much of the reason for the record low MJ MEI is the very strongly + MJ SOI. The 2022 MJ SOI was way up at +17.1, which is 2nd highest (records back to 1876) to 1917's +19.4. In 3rd is 1950's +15.0. In 4th is 1931's +14.2, 5th is 1915's +14.0, and 6th is 1938's +13.9. Where did these 5 other years end up ENSOwise during the subsequent fall/winter dip? One might think good chance for moderate to strong La Niña. However, only one was moderate (1917, the record holder for MJ +SOI), none were strong, and the other four were weak Niña to cold neutral: 1915: weak La Niña/cold neutral border 1917: moderate La Niña 1931: cold neutral 1938: weak La Niña 1950: cold neutral/weak La Niña border Based on this, I'll educatedly guess for now a weak La Niña for the upcoming fall/winter with probably an earlier than average low point. Daily/last 30 days SOI: https://www.longpaddock.qld.gov.au/soi/ Monthly SOI back to 1876: https://data.longpaddock.qld.gov.au/SeasonalClimateOutlook/SouthernOscillationIndex/SOIDataFiles/MonthlySOIPhase1887-1989Base.txt

So, this is a continuation of the sudden reversal toward recovery vs the 2007-21 average that started just after 6/29. It has actually reversed to the best position (+250K) vs that 15 year period since that period started being followed here on June 15th, barely bettering the +240K of 6/20/22. This is a 390K recovery vs that 15 year average over just the last 11 days: Recap of current vs avg. of last 15 years as of: 6/15/22: +70K 6/16/22: +120K 6/20/22: +240K 6/22/22: +140K 6/29/22: -140K 7/1/22: +70K 7/10/22: +250K

Yeah, in summer, there are such large variations within the county on most days. That's the nature of summertime popups just about anywhere as we know. Just a few miles often makes a huge difference. And the variation is increased due to the seabreeze often intersecting the county. Hunter (KSVN), the other station, is much closer to me and got 0.75" vs KSAV's 0.08". But based on following the radar, I did get much more than even Hunter. KSVN (Hunter) link: https://www.wrh.noaa.gov/zoa/getobext.php?sid=ksvn

I think I remember that. Another thing is that I don't recall her or him ever being overly rude or mean. Not once over all of the years. So, a relatively nice troll imo, which makes it hard to get into trouble and thus better allows for longevity. I think that would look good on a troll's resume. Regarding WxWatcher's Gulf update, the 2 PM TWO remains at a 20% chance for a TC over the next five days. With the Gulf very warm to hot and this likely to be slow moving, the big story from this one is liable to be very heavy rainfall along part of the Gulf coast as the 12Z Euro 10 day rainfall map suggests. This is likely overdone but here it is:

Rainfall the last 2 days (all from thunderstorms): 7/8: 0.25"; 7/9: 1.25" Together with the 4" 7/1 and 0.20" 7/7, I'm at 5.7" MTD through 7/9, which is nearly three times the normal for that period and not far from the normal for the entire month. Together with the 7" for June, I'm at 12.7" for the met. summer so far, which is close to the normal for all of June and July, combined. Considering that we've been in a severe drought thanks to well under half the normal rainfall and near the driest in the entire SE US from mid November through May resulting in soil that was almost as hard as concrete, this has been a great turnaround. And now (7/10) we're just starting to get more rain with storms all around. I expect to update this later. Edit for 4:25 PM 7/10 update: preliminary rainfall from today's storm is a whopping 2"+ with all of this falling just over the last hour causing the typical street flooding. It is still raining though it is slowly tapering. My final rainfall amount was right at 2".

I absolutely agree and "she" still seems to be because she's back. If there's such a thing as being graded on trolling, rainstorm gets an A+ from me lmao. Dare I say, she even sometimes made me laugh due to her persistence on saying such over the top nonsense as well as never deviating and being successful. Even the name "rainstorm" embodied her trolling nature. Is that something she can be proud of and put on her resume lol? Do you happen to remember that rainstorm wasn't the first name she went by? She was "jxdama" before (on WWBB).

Besides possible problems with the accuracy of one or both sensors, keep in mind that since June 16th rainfallwise GSO has received more than double the amount at RDU (3.24" vs RDU's mere 1.52"). In summer, large differences in rainfall over a several week period almost always as I assume you realize result in notable differences in especially daytime highs. I noticed the same thing when comparing the not dry Augusta and the very dry Macon a few weeks ago and posted about it. Currently, there's a 6.5 difference between RDU highs MTD vs GSO whereas RDU lows are only 3.1 warmer. Looking at normals, RDU is warmer in July but to a much smaller degree (2.2 for highs and 0.8 for lows). So, that tells me that 4.3 of the difference in highs and 2.3 of the difference in lows this month can't be explained by differences in normals. My educated guess is that a decent portion of the 4.3 for highs is due to rainfall differences the last 3 weeks. To compare to last month, RDU was warmer than GSO but to a much lesser degree with highs 3.2 warmer and lows 1.3 warmer. Normals are higher in June for RDU vs GSO by 2.2 for highs and 0.6 for lows. So, most of the differences in highs last month can be likely attributed to differences in normals. That has clearly changed this month.

From a thunderstorm, I just got my first rain since the big mainly very early morning July 1st 4" rain associated with what later became Colin. So far, totals here today are modest (0.20-0.25" range). But I'll take it after a dry six day period, especially considering that a good portion of that 4" rain likely ran off rather than it saturating. After all, 0.20" is the equivalent of slightly more than one irrigation.