Roger Smith

In the ongoing heat wave BC has seen its previous August record (41.7 C, 2004) broken today (Lytton at 42.1 C, possibly a bit higher in end of day reports). I've had 41.2 C locally (106 F) and it feels about like the 2021 heat dome out there (we reached 44 C in that episode). Pretty sure there are some new August records for WA and OR as well. Brutal heat that will last to Thursday. The windy and perhaps stormy cold front on Friday is causing red flag concerns for current forest fire situation which is generally bad although under control in most cases. Wind gusts to 40-50 mph in that event will create a widespread dangerous situation.

As I posted in another thread, I believe you may get one day of scorching heat around Monday and it could go over 100F. That earlier GFS output showing later heat seems to be out of the picture now, this will be two days of heat Sunday-Monday and a sharp cold front on Tuesday morning. Will go out on a limb and predict 95, 102 for the two days as a regional average.

Well I have 106F outside here today, in that heat dome 2.0 and I'm wondering if a bit of this heat will get into the Mid-Atlantic around Monday of next week? It is certainly going to reposition over the central plains region by the coming weekend. We will end up with four days at or above 100F here in this heat wave and a severe thunderstorm end to it on Friday, probably not what we need to keep a lid on the regional fire situation which is bad but not quite at worst-case scenario levels yet. Rain has been infrequent in the past six weeks but that is normal around here. 106F is about 20 above normal for this location in mid-August. Anyway, keep an eye on Monday. GFS 18z has 582dm thickness near DC. Cold front blasts through overnight so Sunday-Monday is the only hope.

I'm a little outside your region but I do have the heat going on, 106F at my local weather station (Warfield BC) -- I think you may get one day of this heat on Monday from model consensus, Tuesday sees it cut off quickly by a fast-moving cold front before noon. Could peak at 98-102 for you but just one day, we are in middle of five-day heat wave here. Not sweating much, dew point is 43F. Relative humidity is 12%. I suspect you will improve on those numbers and get a brief 100/78 combo on Monday. At the same time, I can see how it fails to reach your region (mid-Atlantic looks more certain) and I can also see how it lasts several days if Tuesday front is a glancing blow. Anyway, Don if you read this, BC August record of 41.7 was set in 2004 and looks likely to fall if not here then at Lytton BC which is at 41.5 this hour. (we are 41.2). This is not quite as bad as the heat dome but close. (later edit 4 p.m. Pacific daylight time, Lytton BC at 42.1 has broken that record, locally we stayed at 41 C).

I expect some serious heat to develop late in August like such years as 1948, 1953 and 1973. That anomaly in the southwest and parts of the northwest U.S. (up to my location, running hot here too) will eventually shift east. It may be near the end of August or maybe early September. But I think it will lead to 100+ days occurring then and setting records.

Those older Chicago area records seem to correlate well with Toronto back to 1840 and to some extent Providence RI back to 1832 (details on those sources are in my thread). For example April 1844 was a lot warmer than most other Aprils of that era. Winters 1855 to 1857 were all very cold for at least some portion (1856 more sustained). Winter 1841-42 was a very mild winter. I have some records copied out from some source for Fort Dearborn in the period 1782 to 1787. They show evidence of a very cold winter in 1783-84. The reversal of temperatures in winter 1857 from Jan (extreme cold) to Feb (record warm) came with severe ice jam flooding in many areas. It basically went from one extreme to another between Jan 22-24 and Feb 7-15. July 1868 was very hot in Toronto and with some adjustment for urban heat island in later data, is fairly close to being as hot as any later summer month. It was quite an outlier, as most other summers of the era were no warmer than what we might consider average. 1854 also had a rather hot summer.

https://www.mag.ncep.noaa.gov/Image.php I found the attached map in the GFS 00z run for yesterday evening, for S America. Don't know if this link will update to the next 00z run or not. If so perhaps somebody can freeze this image (it won't update before 0340z). (link not working, go to GFS maps and select S America, 00z run, any early map -- working on getting a link to show this) Seems to show a sort of winter version of heat dome over central S America. There would probably be a bit of an easterly wind component in coastal Chile downsloping like a strong Santa Ana does in a California warm spell in late winter. Even so it's quite a remarkable map with the 582 dm thickness contours in their version of early February! Made me think of the remarkable warmth we had in BC around Feb 1, 1998, temps were into the 60s and I was out playing golf in summer clothing on a course that nine times out of ten is not open for play in Jan-Feb and can be covered in snow. (an analogue to season and El Nino) -- or the spectacular record breaking going on in Dec 1982 in eastern NA.

Table of forecasts for August 2023 FORECASTER ________________ DCA _NYC _BOS __ ORD _ATL _ IAH ___ DEN _ PHX _SEA Roger Smith __________________ +1.5 _+1.5 _+1.7 __ +2.0 _+2.2 _+3.0 __ -2.0 _+3.5 _+2.0 BKViking ______________________+1.4 _+1.4 _+1.5 __ +0.8 _+1.0 _+2.4 __ +2.4 _+2.5 _+2.2 so_whats_happening __________+1.2 _+1.0 _+1.0 __ +1.5 _+1.3 _+2.0 __ -1.2 _+2.5 _+1.3 wxallannj ______________________+1.2 _+1.0 _+0.8 __ -0.4 _+2.0 _+1.7 __ -0.2 _+2.2 _+2.9 RJay __________________________+1.0 _+1.0 _+1.0 __ +1.0 _+1.0 _ +3.5 __ +3.0 _+3.5 _+1.0 Scotty Lightning ______________+1.0 _+1.0 _+0.5 ___ 0.0 _+1.0 _+1.0 ___ -0.5 _+1.5 _-0.5 ___ Consensus ________________+0.7 _+0.6 _+0.4 __+0.2_+1.2 _+2.0 ____0.0 _+2.1 _+1.7 hudsonvalley21 _______________+0.4 _+0.1 _+0.3 __+0.1 _+1.6 _+1.8 ___+0.4 _+1.5 _+1.7 DonSutherland1 ______________ +0.1 _-0.5 _-0.5 __ +0.2 _+2.0_+2.4 ___+0.7 _+2.0 _+2.1 ___ Normal ____________________ 0.0 __ 0.0 __ 0.0 ___0.0 __ 0.0 __0.0 ___ 0.0 __ 0.0 __0.0 Tom __________________________ -0.3 _-0.2 _-0.2 ___-0.1 _-0.4 _+0.6 __ +1.1 _ +1.3 _+1.4 Rhino16 _______________________-0.3 _-0.8 _-0.6 ___ -0.6 _-0.4 _-0.3 __ -0.5 _-0.6 _+0.7 wxdude64 ____________________-1.1 _ -1.3 _ -1.9 ___ -0.7 _+1.8 _+2.2 __ -0.8 _+2.1 _+1.8 RodneyS ______________________-1.2 _-0.2 _-0.6 ___+0.4 _-0.4 _+1.6 __+0.2 _+1.3 _+0.4 ______________________________ _ _ _ _ warmest and coolest forecasts color coded; all sets include some lower than Normal. This month I will score persistence (July anomalies) ... those are shown below ____ persistence ______________ +0.6 _+1.5 _+1.3 ___+0.3 _+2.2 _+2.7 __ -1.2 _+7.2 _+1.4 Persistence scores 696 against our consensus but PHX adds zero to that total; if persistence scored 900, consensus would score 717 as it would score 21 (and probably higher in a max 60). All other scores would be the same either way. (scores are 100 minus 2x 0.1 errors). Some different possibilities exist in the range between 2.1 and 7.2 for Phoenix, an outcome of 7.2 this month would give 3.5 a score of 49 so max 60 would come into effect. An outcome of 5.5 would give 3.5 a score of 65 and would give persistence a score of 71. It could be said then, our consensus has not strayed far from persistence except that the extreme anomaly at PHX is not expected to repeat. Our closest call to a repeat is +3.5 from RJay and Roger Smith. Seasonal max values will be imported into this thread in a few days. Updated seasonal max to date (Aug 26 2023) _ 97 _ 93 _ 91 ___100 __ 99 __ 109 _____ 99 __ 119 __ 95

This event seems to be correlated in latitude, timing and intensity by the recent broiling heat wave in the central Mediterranean region, which peaked about a week ago, with temperatures near all-time highs in parts of Tunisia, Sicily, southern mainland Italy, Albania, Greece and western Turkey. For example it was 45.6 C on July 25 at Catania, close to their previous all-time high of 46.0. Values of 48-49 C were reported from central Tunisia including Sfax where the previous all-time record was 47 C. One report from Greece was actually closer to 60 C but may be either an error or fire-affected. Severe wildfires erupted all over the hot zone. Some believe that these super heat waves are the combined result of ongoing AGW climate change and after-effects of the water vapour eruption of the Tonga undersea volcano last year. The central Med heat wave (which was not quite as relentless as the Arizona version, a few days recently have been temperate) was the result of a depressed jet stream in July over the Atlantic forcing superheated Saharan air to escape northeast, with less of a west to north exit or a southwesterly exit over the Atlantic, that are more normal outcomes. In some past years Saharan heat has spilled into Spain and Portugal then on to France and western Europe in general. This year's setup with depressed heights over the Iberian peninsula has prevented that and Spain has been more moderate, while France and Britain, Ireland have been a bit cooler than average for July after quite a warm June. CET values were 17.0 June (5th warmest) and 16.1 July (near median of all data and 0.7 below recent 30-yr normal). An average for five locations in Ireland was 15.1 C, 1981-2010 average 15.5 C. There are signs of a return to previous years' western Europe heat plume in mid-August however. My take is that the southwest heat dome will come back to life during August, spread north and then east. This may be an August similar to 1948, 1953 and 1973 all of which were fairly close to average in the east until the last week, then went into broiling heat waves with many records set. Then I speculate that this anomalous warmth will set up over eastern NA for most of the autumn, although the statistical correlation seems to be warm September and November, cool to average October.

+1.5 __ +1.5 __ +1.7 __ +2.0 __ +2.2 __ +3.0 __ -2.0 __ +3.5 __ +2.0

=== === <<<< ---- ANNUAL SCORING for JANUARY - JULY 2023 ---- >>>> === === Best scores for the nine locations are shown with red highlight, best totals for regions in bold. Scoring ranks mainly unchanged in July except for Tom moving past Roger Smith into 9th. Some margins have changed. FORECASTER ______________ DCA_NYC_BOS__east__ORD_ATL_IAH__cent ___ c/e___ DEN_ PHX_ SEA __ west __ TOTALS DonSutherland1 ___________ 432 _408 _ 448 __1288 __504 _510 _468 __1482 __2770 __451 _410_520 __1381 ____4151 RJay _______________________ 430 _444 _ 431 __1305 __ 525 _454 _476__ 1455 __2760 __341 _415 _541 __1297 ____4057 wxallannj __________________ 425 _440 _ 457 __1322__ 555 _478 _420__ 1453 __2775 __429 _424 _414 __1267 ____4042 ___ Consensus _____________403 _406 _ 455 __1264__ 515 _422 _455 __1392 __2656 _ 381 _397 _522 __1300 ____3956 hudsonvalley21 ____________411 _408 _ 477 __1296 __ 526 _425 _437 __1388 __2684 __352 _350 _533 __1235 ____3919 RodneyS __________________ 396 _390 _422 __1208 __ 349 _395 _478 __1222 __2430 _ 447 _428 _524 __1399____3829 wxdude64 _________________398 _387 _394 __1179 __ 417 _454 _404 __1275 __2454 __ 491 _380 _486 __ 1357 ____3811 BKViking ___________________410 _402 _443 __1255 __477 _414 _461 __ 1352 __2607 __323 _ 330 _412 __1065 ____3672 Scotty Lightning ___________341 _366 _412 __ 1119 __469 _355 _434 __1258 __2377 __ 332 _288 _416 __ 1036 ____3413 ... pro-rated scores are added in brackets for most below this point in the table ... Tom's unimproved score is now a bit ahead of mine ... Tom (6/7) __________________357 _354 _373 __1084 __346 _362 _420 __1128 __2212 __342 _306 _429 __1077 _____3289 (3837) Roger Smith _______________ 362 _312 _340 __1014 __383 _295 _422 __1100 __2114 __321 _326 _502 __ 1149 ____ 3263 ___ Normal _________________292 _306 _342 __ 940 __410 _358 _348 __1116 __ 2056 __372 _ 310 _416 __1096 ____ 3152 Rhino16 (4/7) ______________212 _228 _250 ___ 690 ___310 _288 _216 ___814 __1504 __209 _212 _288 __ 709 ____ 2213 (3873) Stormchaser Chuck (3/7) __201 _238 _196 ___ 635 ___257 _132 _146 ___535 __ 1170 __238 _240 _238 __ 716 ____1886 (4401) so_whats_happening (3/7) _124 _126 _ 180 ___ 430 __ 169 _105 _180 ___ 454 ___884 __122 __168 _218 __ 508 ____1392 (3248) Terpeast (1/7) ______________ 62 _ 44 _ 34 ____ 140 ___84 _ 86 _ 26 ____ 196 ___ 336 __ 10 __ 76 __ 60 __ 146 ____ 482 (3374) rainsucks (1/7) _____________ 42 __32 _ 36 ____ 110 ___ 00 _ 66 _ 48 ____ 114 ___ 224 __ 50 __ 98 __ 84 __ 232 ____ 456 (3192) - - - - - ___ Persistence ____________287 _254 _348 __ 889 ___378 _ 341 _ 422 __1141 ___2030 __ 192 _ 344 _ 370 __ 906 ____ 2936 _______________________________________________________ Best Forecasts * shared with one other forecaster for one month (does not apply to Consensus or Normal, if they qualify, so does the high forecaster score whether tied or not) FORECASTER ____________ DCA_NYC_BOS__east__ORD_ATL_IAH__cent_ c/e__ DEN_PHX_SEA__west __ Months DonSutherland1 ___________ 0 ____ 0 ____ 0 ___ 0 ____ 2*____2*____0____ 2 ___ 1 ___ 1 ___ 2 ___ 2*___1 ____2 _ Jan,Mar RJay _______________________ 1 ____ 3 ____ 1 ____2 ____ 1*___3**___3 ___ 1 ___ 2*___ 0___ 2* ___ 1 ___0 ____0 wxallannj __________________ 0 ____ 0 ____ 1 ___ 1 ____2**___1 ____0 ___ 1 ___ 2*___ 1 ___ 0 ___ 0 ___ 0 ____ 1* _ May(t),July ___ Consensus ____________ 0 ____ 0 ____ 0 ___ 0 ____ 0 ____0 ____0 ___ 0 ___ 1 ___ 0 ___ 1 ___ 1 ___ 0 ____ 1 __ May hudsonvalley21 ____________1*____ 1 ____ 1 ___ 0 ____ 0^____0 ____1* ___0 ___ 0 ___ 0 ___ 0 ___ 0 ___ 1 ____ 1* _ May(t) RodneyS __________________2*____ 1 ____ 1 ___ 2 ____ 0 ____ 1 ____0 ___ 0 ___ 1 ___ 2 ___ 2 ___ 1* ___ 3 ____1 _ Jun wxdude64 _________________0 ____ 0 ____ 0 ___ 0 ____ 1*____1 ____0 ___ 1 ___ 1 ___ 1 ___ 0 ___ 0 ___ 1 ____ 1 _ Apr BKViking __________________ 0 ____ 0 ____ 0 ___ 0 ____ 1*____ 0 ____0 ___1 ___ 0 ___ 0 ___ 1* ___1 ___ 0 ____0 Scotty Lightning ___________1 ____ 1 _____ 1 ____ 1 ____ 0 ____0 ____0 ___ 0 ___ 1 ___ 0 ___ 1* ___1 ___ 0 ____0 Tom (6/7) _________________ 1*____ 0 ____ 0 ___ 0 ____ 0 ____0 ____2*___ 0 ___ 0 ___ 0 ___ 0 ___ 0 ___ 0 ____0 Roger Smith _______________ 0 ____ 0 ____ 0 ___ 0 ____2**___0 ____1 ___ 0 ___ 0 ___ 0 ___ 0 ___ 1 ___ 0 ____0 ___ Normal _________________0 ____ 2 ____ 0 ___ 0 ____ 0 ____0 ____ 1 ___ 0 ___ 0 ___ 1 ___ 0 ___ 1 ___ 0 ___ 0 Rhino16 (4/6) ______________ 0 ____ 0 ____ 0 ___ 0 ____ 0 ____0 ____0 ___ 1 ___ 0 ___ 1 ___ 0 ___ 0 ___ 0 ____0 Stormchaser Chuck (3/6) __2 ____ 1 ____ 1 ___ 1 ____ 2 ____ 1* ____ 1 ___ 0 ___ 0 ___ 1 ___ 0 ___ 1 ___ 1 ____1 _ Feb so_whats_happening (3/6) _0 ____ 0 ____ 1 ___ 0 ____ 0 ____0 ____0 ___ 0 ___ 0 ___ 0 ___ 0 ___ 0 ___ 0 ____0 Terpeast (1/6) _____________ 1*____ 0 ____ 0 ___ 0 ____ 0 ____0 ____ 0 ___ 0 ___ 0 ___ 0 ___ 0 ___ 0 ___ 0 ____0 rainsucks (1/6) ____________ 0 ____ 0 ____ 0 ___ 0 ____ 0 ____0 ____ 0 ___ 0 ___ 0 ___ 0 ___ 1*___ 0 ___ 0 ____0 (hudsonvalley21 has a tied top score for ORD (Mar) before 1 pt reduced by penalty). Shown as 0^ ----------------------------------------- EXTREME FORECAST SUMMARY So far, 53 of 63 forecasts qualify, 30 of them for warmest, and 23 for coldest ... Jan 6-2, Feb 5-3, Mar 6-3, Apr 5-3, May 3-2, June 1-8, July 4-2 ... 12 of 53 involve a loss where a second ranked forecast has high score. Two of those are a shared loss. FORECASTER _______ Jan _ Feb _ Mar _Apr _May _ Jun _Jul __ TOTALS _ (adjusted for ties) RJay _________________ 5-0 _ 2-1 _ 2-0 _ 1*-0_ 0-0 _ 1-0 _4-0 __ 15-1 ______14.5 - 1.0 StormchaserChuck __ -- --_ 5-1 _ -- --_ 2-2 _ 2-0 _ --- _ --- ___ 9-3 ______ 8.5 - 3.0 RodneyS _____________1-0 _ 1-0 _ 1-0 _ 1-0 __ 1-0 _ 4*-1 _0-1 ___ 9-2 ______ 8.5 - 2 DonSutherland ______ 2-0 _ 1-0 _ 3*-1 _ 1-0 _ 0-0 _ 1-0 _ 0-0 ___ 8-1 ______ 7.5 - 1.0 Scotty Lightning _____ 0-0 _ 0-0 _ 3-1 _ 0-1* _ 0-0 _ 1-0 _0-0 ___4-2 ______ 4.0 - 1.5 ___ Normal ___________ 0-0 _ 0-0 _ 0-1 _ 1-0 _ 0-0 _ 3-0 _0-0 ___ 4-1 _______ 4.0 - 1.0 Roger Smith _________ 1-0 _ 0-0 _ 0-0 _ 1*-0 _ 1-1*_ 0-0 _1*-0 ___ 4-1 ______ 3.0 - 0.5 hudsonvalley21 ______ 0-0 _ 0-0 _ 1*-0 _1-0 _ 1*-0 _ 0-0 _0-0___ 3-0 ______ 2.0 - 0 wxallannj ____________ 0-0 _ 0-0 _ 0-0 _ 1*-1* 0-1* _ 2*-0_1-0 ___ 4-2 ______ 3.0 - 1.0 Tom __________________0-0 _ 0-0 _ 0-0 _ 1-0 _ 1*-0_ 0-0 _ 0-0 __ 2-0 ______ 1.5 - 0 wxdude64 ___________1-0 _ 0-0 _ 0-0 _ 0-0 _ 0-0 __ 0-0 __1*-1 __ 2-1 ______ 1.5 - 1.0 rainsucks _____________ -- --_-- --_-- --_1*-0 _ -- - _ ---- _ --- ___ 1-0 ______ 0.5 - 0 BKViking _____________ 0-0 _ 0-0 _ 0-0 _0-0 _ 0-0 _ 1*-0 _ 0-0 ___ 1-0 ______ 0.5 - 0 Terpeast _____________ -- --_-- --_-- --_ -- --_ -- - _ 1*-0 _ --- ___ 1-0 ______ 0.5 - 0 so_whats_happening _0-0 _0-1 _ -- --_ -- -- _ -- - _ 0-0 _ --- ___ 0-1 _______ 0.0 - 1 ===========================================

Ranking tables normally account for ties and the case mentioned would be 11th warmest, after five tied at 6th warmest. It would not or at least should not be ranked seventh warmest. Some tables including CET differentiate by second decimals not visible in the table. The apparently tied months are marginally separated by these unprinted second decimals. In some ranking tables, it is up to you to establish ties, the table may be printed without ties identified. Most commonly, that kind of table will have the tied years listed in chronological order. But with everyone tweeting their own versions of climate stats, it is wise to find out whether they respect conventional ranking protocols or not. Also a top ten from a record of thirty years is obviously a bit easier to establish than a top ten from 155 years like NYC or 183 like Toronto. Another source of minor confusion in at least one prominent set of ranks (CET) is the practice of leaving the warmest rank blank until it happens, for example, this is what you see if you click on monthly ranks for CET ... at the bottom of the rankings where they place the warmest months, you find 1st (ranks on right, the ranks on left are in the sense of coldest of 355 in their records) blank for July to December ... further up the table you need to remember that what appears to be 40th warmest August is actually 39th warmest August. (EXCERPT of CET monthly rankings) 355 6.5 1686 6.9 1961 8.0 2022 10.2 1796 13.5 1868 16.4 1818 18.4 1808 18.0 1990 15.6 1780 12.5 1968 8.9 1881 7.3 1857 10.6 1990 11 356 6.6 1898 6.9 2019 8.1 1734 10.2 1944 13.5 1919 16.6 1775 18.4 2013 18.1 1955 15.6 1999 12.6 1959 9.1 1817 7.3 1988 10.6 1999 10 357 6.7 2008 6.9 2022 8.2 1750 10.3 1987 13.5 1947 16.8 1858 18.5 1995 18.2 1911 15.7 1760 12.7 1831 9.2 2022 7.4 1843 10.6 2017 9 358 6.7 1983 7.0 2002 8.2 1961 10.3 1893 13.5 1784 16.9 1798 18.5 1921 18.3 1747 16.0 1795 12.7 1995 9.2 1730 7.4 1828 10.6 1949 8 359 6.8 1975 7.1 1903 8.3 1990 10.3 2014 13.6 1992 16.9 1976 18.6 1976 18.3 2003 16.0 2021 12.8 1921 9.3 1743 7.5 1710 10.7 2018 7 360 6.9 1733 7.1 1945 8.3 1948 10.3 1798 13.6 1727 16.9 1762 18.7 1852 18.6 1947 16.1 2016 12.8 2022 9.4 1938 7.6 1733 10.7 2011 6 361 7.0 2007 7.2 1794 8.4 2012 10.5 1943 13.7 1808 17.0 2023 18.8 1783 18.6 1975 16.3 1949 12.9 2006 9.4 2015 7.7 1852 10.8 2020 5 362 7.1 1834 7.2 1998 8.4 1997 10.5 2020 13.8 1788 17.1 1822 19.2 2018 18.7 2022 16.3 1865 13.0 2005 9.5 1818 7.9 1974 10.9 2006 4 363 7.3 1796 7.3 1990 8.8 2017 10.6 1865 13.8 1758 17.3 1826 19.4 1983 19.0 1997 16.6 1729 13.1 1969 9.5 2011 8.1 1934 11.0 2014 3 364 7.3 1921 7.5 1869 9.1 1938 11.3 2007 13.9 1848 18.0 1676 19.8 2006 19.1 1995 16.9 2006 13.2 2001 9.9 1994 9.6 2015 11.1 2022 2 365 7.6 1916 7.9 1779 9.2 1957 11.9 2011 15.1 1833 18.2 1846 --- 2023 --- 2023 --- 2023 --- 2023 --- 2023 --- 2023 --- 2023 1

I am only seeing 96 at BWI, 97 at DCA is the lone increase today. Scoring table will be adjusted.

According to my stats, since the top ten cold month of Feb 2015, these top ten warm months have been recorded at NYC, near miss 11-15 cases shown in ((( triple brackets ))) ... these are not adjusted for urban heat island, some of these ranks would fall slightly if a progressive u.h.i. adjustment was applied ... : JAN _ 1 (2023) ... (((12 2020))) FEB _ 1 (2018) .. 2 (2017) .. 3 (2023) .. t8 (2020) MAR _ 4 (2016) .. 7 (2020) .. (((t13 2021))) APR _ 2 (2023) .. 3 (2017) .. (((t13 2019))) MAY _ 2 (2015) .. 6 (2018) JUN _ t6 (2021) JUL _ 7 (2020) .. ((( t11 2019, t13 2022 ))) AUG _ 3 (2022) .. 4 (2016) .. 5 (2015) .. t10 (2018) SEP _ 1 (2015) .. t10 (2016) OCT _ 1 (2017) .. 6 (2021) NOV _ 1 (2020) .. 2 (2015) .. (((13 2022))) DEC _ 1 (2015) .. t3 (2021) ________________ That is a total of 25 top ten months and 31 top 15. Feb 2015 was third coldest and since then the highest ranking cold month is t31 coldest Nov 2019.

Current standings as of July 29, 2023 Table remains in forecast table order for now. Errors underlined are the few that are forecasts already passed by actual maxima so far. __ Max values to date ____________ 97 __ 98 __ 97 __ 98 The qualifier for rank is the separation of equal error totals by the rules outlined earlier. This table will be adjusted if or when necessary, and if not, it will be posted again in rank order later in the summer. (table adjusted July 29 for DCA 97) FORECASTER (order of entry) __ DCA _ IAD _ BWI _ RIC _____ Errors ____Total __ Rank __ qualifier (to separate tied totals) GeorgeBM ( 8 ) _________________ 105 _ 103 _ 106 _ 104 ______ 8 5 9 6 ___ 28 ____ 26 StormchaserChuck1 ( 1 ) ________ 104 _ 103 _ 103 _ 104 ______7 5 6 6 ___ 24 ____25 Roger Smith _____________________ 102 _ 102 _ 103 _ 103 ______5 4 6 5 ___ 20 ____ 23 H2O (20) _________________________102 _ 101 _ 102 _ 102 ______ 5 3 5 4 ___ 17 ____20 __ 2nd lowest error (3) ChillinIt (15) ______________________102 __ 98 _ 103 _ 104 ______ 5 0 6 6 ___ 17 ____19 __ lowest lowest error (0) Rhino16 ( 2 ) _____________________ 101 _ 103 _ 102 _ 105 ______ 4 5 5 7 ___ 21 ____24 mattie g (17) ______________________101 _ 103 _ 101 _ 102 ______ 4 5 4 4 ___ 17 ____21 __ highest lowest error (4) wxdude64 (16) ___________________101 __ 99 _ 101 __ 102 ______4 1 4 4 ___ 13____ 17 __ lower lowest error (1) soundmdwatcher (23) ___________ 100 _ 102 _ 104 _ 102 ______3 4 7 4 ___ 18 ____22 Terpeast ( 6 ) ____________________ 100 _ 101 _ 101 _ 100 ______ 3 3 4 2 ___ 12 ____16 __ higher lowest error (2) tplbge (24) _______________________100 _ 100 _ 102 _ 101 ______ 3 2 5 3 ___ 13 ____18 __ higher lowest error (2) GramaxRefugee (19) _____________100 __ 99 _ 100 _ 100 ______ 3 1 3 2 ____ 9 ____10 __ later entry toolsheds (18) ____________________100 __ 98 _ 101 _ 102 ______ 3 0 4 4 ___ 11 ____14 biodhokie (25) ____________________ 99 _ 101 __ 99 _ 101 ______ 2 3 2 3 ___ 10 ____13 __ higher lowest error (2) RickinBaltimore ( 7 ) ______________ 99 __100 _ 100 __ 99 ______ 2 2 3 1 ____ 8 ____ 8 WinstonSalemArlington (22) ______ 99 __ 99 _ 103 _ 101 ______ 2 1 6 3 ___ 12 ____15 __ lower lowest error (1) nw baltimore wx ( 3 ) _____________ 99 __ 99 _ 101 _ 100 ______ 2 1 4 2 ____ 9 ____ 9 __ earlier entry Weather53 (13) ___________________ 99 __ 99 _ 100 _ 101 ______ 2 1 3 3 ____ 9 ____11 __ higher second lowest error (3 vs 2 for 9th, 10th) WxUSAF ( 4 ) _____________________ 99 __ 99 _ 100 __ 99 ______ 2 1 3 1 ____ 7 _____ 7 __ higher lowest error (1) katabatic ( 9 ) _____________________99 __ 98 _ 100 _ 100 ______ 2 0 3 2 ____ 7 _____ 6 __ lower lowest error (0) NorthArlington101 (21) ____________ 99 __ 97 __ 99 __ 99 ______ 2 1 2 1 ____ 6 _____ 4 __ later entry Stormpc (14) ______________________98 _ 102 __ 101 __ 99 ______ 1 4 4 1 ___ 10 ____12 __ lower lowest error (1) MN Transplant ( 5 ) _______________ 98 __ 99 _ 100 __ 99 ______ 1 1 3 1 ____ 6 _____ 3 __ earlier entry Its a Breeze (12) __________________ 98 __ 99 __ 99 _ 100 ______ 1 1 2 2 ____ 6 _____ 5 __ higher second lowest error WxWatcher007 (11) _______________ 98 __ 97 __ 99 __ 99 ______ 1 1 2 1 ____ 5 _____ 2 LittleVillageWx (10) _______________ 98 __ 97 __ 98 __ 98 ______ 1 1 1 0 ____ 3 _____ 1

Three locations tied the above values (previous post) and RIC went to 98F on July 28. Edited previous post. edited again July 29 for DCA 97F. IAD added another tied 98F.

DCA slagged for a low temperature report? Now we've seen everything. DonS, have you been following Mediterranean heat wave. I think it peaked around Monday-Tuesday with quite a few locations near all-time record highs. One example, Catania on east coast of Sicily, 45.6 C (all-time record high 46.0). Some locations in Tunisia may have exceeded all-time records near 49 C (120F). Similar setup to Arizona heat wave, the heat tries to move north but so far this summer central and northern Europe have remained relatively temperate. British Isles had warmer June than July for first time since 1970 and it wasn't even close, CET 17.0 June then around 16.1 for July. It was fifth warmest June on record in Britain, and warmest since 1846. All four warmer years were well back, 1846, 1826, 1676 and 1822 were warmer. June is the only month in the CET series with records mainly confined to pre-modern warming era although May is almost the same and its warmest month was 1833. The twelve months in CET (which spans 1659 to present) have these years as warmest on record: Jan 1916, Feb 1779, Mar 1957, Apr 2011, May 1833, June 1846, July 2006, Aug 1995, Sep 2006, Oct 2001, Nov 1994, and Dec 2015. The warmest year was 2014. The warmest day was last July 19th. June 1676 is the only "Maunder month" to crack any top five and in general the Maunder minimum period is about a Celsius degree colder than the overall average and almost 2 C colder than recent 30-year averages. Before this modern warming era, 1721 to 1739 was a relatively warm interval, and 1818 to 1834 was often quite warm despite some cold winters.

Popping in to remind the usual suspects to enter the August temperature forecast contest over in the sleepy realm of the general weather forum. I don't know if there's an admiral weather forum.

Naturally interested in these data summaries, see my Toronto and New York City data analyses in the climate change forum here. If somebody can post links to all similar data for Chicago I could work up simiar tables. FWIW my urban heat island assessment for Toronto is an average increase of 1.1 C or 2.0 F occurring in 0.1 C increments per decade, starting with 1881-1890 when the city began to surround the location of the now-downtown (but originally edge of town) university campus location. Of course this is an average for different situations, a cool, dry month with a lot of clear nights would have a larger differential than a humid, wet month. I have applied the same set of adjustments to NYC data with the assumption that a larger heat island of 1.4 C began to appear before NYC data started in 1869. That makes the period 1869 to 1880 if unadjusted, 0.2 C warmer, and the first decade adjusted for Toronto 0.3 C warmer (1881-90). But as the data are only being ranked against each other, those additional adjustments make no difference to ranking outcomes. Is there a link to daily records, and if so, would ORD have incorporated older records from a different location? If not, is there a set of daily records that does span a longer interval? As it happens, it took only four days for Toronto to establish its first daily record (March 4th, 1840) that has somehow managed to persist to the present time. There are very few others on the warm side that lasted very long. One factor for Toronto is that a cooling lake breeze could more easily reach the location of the downtown weather station before the advent of multi-storey buildings around 1900. This wall of skyscrapers nowadays is a real inhibiting factor and the lake breeze tends to make better progress inland on either side of downtown Toronto. I suppose for Chicago the frequency of cooling lake breezes would be lower given the wind directions involved. Toronto is quite often in a south to east wind flow in spring anyway so the lake breeze is quite often a factor there.

Update ... DCA __ 97 on July 29 IAD ___ 98 on July 27, 28, 29 BWI ___ 97 on June 2 and July 27, 28 RIC ___ 96 on July 27 then 98 on July 28 Made several updates to July 29 ...

Predict temp anomaly (F deg) relative to 1991-2020 average, for DCA _ NYC _ BOS __ ORD _ ATL _ IAH ___ DEN _ PHX _ SEA deadline 06z Tuesday August 1st. No assembly required. State and local taxes may apply. Co-pay available.

Good chance of near 100F on Friday? One day wonder. If that southwest heat wave ever got fully released ... but it looks like a brief blast from that source as the southwest heat dome connects briefly to the distant Atlantic ridge. May last into Saturday for RIC possibly.

Touch and go whether the severe heat makes it into NYC or gets cut off around central NJ on Friday but what looks more certain is a chance of severe storms on Saturday as a strong wave forms around Ohio and moves towards n NJ and NYC. My guess is something like 95-100F in central NJ on Friday, 92-95 F at NYC airports, 85-90 at ISP and POU then 2-3" rain potential (hit or miss probably) across the region on Saturday. The southwest heat dome is currently at 600 dm over NM and is supposed to start deflating gradually over next five days to the low 590s allowing more of a typical monsoon mid-summer pattern to replace the magnifying glass effect. By this weekend there could be some monsoon storms forming over AZ. I notice the heat has moved as far north as the southern tier of counties in Nebraska but not so much beyond that, Omaha was only into the mid-80s while Topeka was 102. That is probably a precursor of a similar sharp gradient with the heat as it makes its one or two day presence felt further east, but the southwest ridge and the Atlantic ridge never make much of a connection before it all collapses this weekend. With that heavy rain potential on Saturday, temps could be between 75 and 80 during the rain but highs could reach 85-90 in any sunshine.

As of today, summer max ... ... DCA __ 94 on June 2 and July 13 IAD ___ 96 on July 13 BWI ___ 97 on June 2 (96 on July 13) RIC ___ 94 on July 4, 13

Remains to be seen where 2023 may fit into this summary: MAXIMUM TEMPERATURES of YEARS 1869 to 2022 106 _ 1936 104 _ 1918, 1977, 2011 103 _ 1948, 1966, 2001, 2010 102 _ 1930, 1933, 1944, 1949, 1953, 1980, 1991, 1993, 1995 101 _ 1881, 1934, 1957, 1999 100 _ 1898, 1901, 1911, 1917, 1926, 1937, 1952, 1954, 1955, 2012 99 _ 1885, 1919, 1923, 1924, 1925, 1929, 1931, 1943, 1956, 1962, 1964, 1983, 1988, 2005 98 _ 1876, 1879, 1890, 1891, 1896, 1940, 1941, 1963, 1968, 1973, 1975, 1982, 1986, 1994, 2002, 2013, 2021 97 _ 1892, 1895, 1900, 1912, 1942, 1945, 1959, 1961, 1969, 1987, 1997, 2006, 2015, 2022 96 _ 1872, 1880, 1887, 1888, 1894, 1905, 1908, 1921, 1932, 1938, 1939, 1967, 1971, 1976, 1981, 1984, 1989, 1996, 2008, 2016, 2018, 2020 95 _ 1869, 1883, 1893, 1899, 1903, 1913, 1914, 1916, 1935, 1947, 1950, 1965, 1974, 1978, 1979, 1985, 1990, 2019 94 _ 1870, 1873, 1878, 1886, 1904, 1906, 1910, 1915, 1920, 1922, 1928, 1946, 1951, 1970, 1972, 2003, 2017 93 _ 1874, 1875, 1882, 1897, 1909, 1958, 1992, 1998, 2000 (2023 so far) 92 _ 1871, 1877, 1907, 1927, 2007, 2009, 2014 91 _ 1884, 1889, 1960, 2004 90 _ 1902