bluewave

Not quite. There were a number of extreme conditions about in 2019/2020 which perhaps point to a common driver in the Indian Ocean. In the fullness of time we may find a unifying explanation for the SH SSW, QBO disruption and record cold/strong NH PV. Abstract The quasi-biennial oscillation (QBO) is a repeating cycle of tropical stratosphere winds reversing direction from eastward to westward roughly every 14 months. Discovered independently by British and American scientists the QBO continued undisturbed for 27 cycles from 1953 until February 2016 when a westward jet unexpectedly formed in the lower stratosphere during the eastward phase. This disruption is attributed to unusually high wave momentum fluxes from the Northern Hemisphere. A second, similar, QBO disruption occurred during the 2019/2020 northern winter though this time the Arctic polar vortex was exceptionally strong and wave fluxes weak. Here we show that this latest disruption to the regular QBO cycling was twice as strong as that seen in 2016 and resulted from horizontal momentum transport from the Southern Hemisphere. The disruption began in September 2019 when there was a rare Southern Hemisphere sudden stratospheric warming followed by abnormal conditions in the stratosphere with the smallest ozone hole since its discovery and enhanced equatorward momentum fluxes. In both disruptions the normal downward progression of the QBO halts and the eastward shear zone above the disruption moves upward assisted by stronger tropical upwelling during the boreal winter. Results from the two disruptions provide compelling evidence of a fundamental change in our understanding of the dynamics of the QBO with extra-tropical influences more significant than previously thought. In turn, this implies a less predictable QBO. Furthermore, the expected climate response of the mechanism we have identified suggests that reoccurring QBO disruptions are consistent with an emerging signal of climate change weakening QBO amplitudes as predicted by models.

The blocking from Siberia to the Great Lakes almost looks like a cold season pattern.

Top 2 driest pattern for several stations since the pattern change back in mid-May. Not much rain in the forecast. Time Series Summary for Bridgeport Area, CT (ThreadEx) Click column heading to sort ascending, click again to sort descending. Rank Ending Date Total Precipitation May 17 to Jun 23 Missing Count 1 1957-06-23 0.63 0 2 2020-06-23 0.75 0 Time Series Summary for LAGUARDIA AIRPORT, NY Click column heading to sort ascending, click again to sort descending. Rank Ending Date Total Precipitation May 17 to Jun 23 Missing Count 1 2020-06-23 1.12 0 Time Series Summary for ISLIP-LI MACARTHUR AP, NY Click column heading to sort ascending, click again to sort descending. Rank Ending Date Total Precipitation May 17 to Jun 23 Missing Count 1 1964-06-23 1.17 0 2 2020-06-23 1.21 0

Almost like the Siberian version of our December 2015 +13 departure lasting for months. Wonder what our actual departures would be for a 5 month equivalent 5 sigma event?

This is one of those rare times when the WAR forecast has been getting weaker day 8 from day 10. We got used to the pattern of it correcting stronger day 8-10. The trough digging into the West also was a signal for an easy high temperature guidance beat. Maybe a combo of the developing La Niña, Indian Ocean warmth, and that perma-heat ridge which has been stuck over a Siberia.

We may get some pretty sunsets this weekend if the SAL forecast works out.

Unusual ring of ridging to our north across the Northern Hemisphere since last late May. Keeps us in an easterly flow with record warmth to our north and west. So we get these omega block type patterns that occasionally extend into Northern New England. The first in late May had the new May all-time high temperature for BTV. Most recently, CAR had their all-time June high. Albany recorded a daily record high yesterday. The models now continue this general pattern into at least early July. So this year we are getting and early summer pattern that actually began in late May.

Looks like a top 5 driest June through the 22nd for your area. Time Series Summary for POUGHKEEPSIE AIRPORT, NY Click column heading to sort ascending, click again to sort descending. Rank Ending Date Total Precipitation Jun 1 to Jun 22 Missing Count 1 1993-06-22 0.00 8 2 1949-06-22 0.02 0 3 1988-06-22 0.29 0 4 2020-06-22 0.30 0 5 1957-06-22 0.40 0

The OP Euro has been having these big run to run swings day 6-10 recently. But you can see the EPS moving toward a stronger omega blocking pattern now. New run Old run

Models going for a -NAO drop with a continuing omega block in the 6-10 day forecast. So this may keep the strongest heat to our west at that time. Lower heights possible over New England with high pressure to the north. So this week could turn out to be warmer than next week.

Another day with the heat records to our north.

It will be interesting to see how far north this record breaking SALcan get.

Our own version of the trade winds. Imagine if our SSTs approached the warmth around Florida.

With another dry week coming up, this will be the driest mid-April to late June from LGA to ISP. Time Series Summary for LAGUARDIA AIRPORT, NY Click column heading to sort ascending, click again to sort descending. Rank Ending Date Total Precipitation May 16 to Jun 26 Missing Count 1 2020-06-26 1.12 6 2 1965-06-26 1.51 0 3 1949-06-26 1.81 0 4 2005-06-26 1.95 0 5 1963-06-26 2.45 0 Time Series Summary for ISLIP-LI MACARTHUR AP, NY Click column heading to sort ascending, click again to sort descending. Rank Ending Date Total Precipitation May 16 to Jun 26 Missing Count 1 2020-06-26 1.22 6 2 2005-06-26 1.34 0 3 1964-06-26 1.37 0 4 1986-06-26 1.91 0 5 1965-06-26 2.06 0

Rainfall pattern looks familiar.

Probably need to shift the blocking ridges from the Upper Midwest to east of New England. Large sections of the US have been dry this month. Parts of New England have had their driest mid-May to Mid-June on record.

All-time June high temperature tied at Caribou. But the all-time record for any month was probably in August 1935 before record keeping began. PUBLIC INFORMATION STATEMENT NATIONAL WEATHER SERVICE CARIBOU ME 248 PM EDT FRI JUN 19 2020 ...PRELIMINARY PUBLIC INFORMATION STATEMENT... THE PRELIMINARY HIGH TEMPERATURE THIS AFTERNOON IN CARIBOU, MAINE WAS 96 DEGREES (F). THIS TIES FOR THE ALL-TIME HIGH TEMPERATURE IN CARIBOU. THE ALL-TIME RECORD OF 96 DEGREES WAS FIRST ESTABLISHED ON JUNE 29, 1944 AND AGAIN ON MAY 22, 1977. THIS STATEMENT WILL BE UPDATED IF WE BREAK THE ALL-TIME RECORD. IT IS VERY IMPORTANT TO POINT OUT THAT WEATHER RECORDS IN CARIBOU BEGAN ON JANUARY 16, 1939, AND THUS DO NOT INCLUDE ALL OF THE 20TH CENTURY. PRESQUE ISLE, MAINE HAS OBSERVED A HIGH OF 99 DEGREES ON 2 DAYS. THE FIRST WAS ON JULY 11, 1911, AND AGAIN ON AUGUST 18, 1935. ON AUGUST 18, 1935, WOODSTOCK (CLOSE TO HOULTON, MAINE), NEIPISGUIT FALLS, AND REXTON NEW BRUNSWICK ALL OBSERVED A HIGH OF 103 DEGREES. EDMUNSDSTON, NEW BRUNSWICK JUST ACROSS THE BORDER FROM MADAWASKA, MAINE OBSERVED A HIGH OF 99 DEGREES ON JUNE 3, 1919. MILLINOCKET, MAINE HAS OBSERVED A HIGH OF 100 DEGREES ON THREE OCCASIONS WITH AN ALL-TIME HIGH OF 101 DEGREES ON JUNE 18, 1907. THE ALL-TIME RECORD HIGH IN BANGOR IS 104 DEGREES ON AUGUST 19, 1935. IT IS PROBABLE, AND EVEN LIKELY THAT CARIBOU HAD A HIGH TEMPERATURE WARMER THAN 96 DEGREES ON AUGUST 18, 1935, BUT BECAUSE WEATHER RECORDS DID NOT EXIST AT THE TIME THERE ARE NO RECORDS.

Very impressive warmth in that region.

Parts of Siberia are around +14°F for January through May.

The 95 record high at Caribou is just 1 degree from their all-time record high temperature.

The Euro has an impressive extended heatwave for New England over the next week. Double digit 7-day temperature departures.

The high so far of 94 at Caribou is just 2 degrees from the all-time record high of 96 degrees. The all-time record high in Caribou is 96F, last set on May 22, 1977. There was one other occurrence of a high of 96F, on June 29, 1944. There have been only 9 times in Caribou with a high of 95F, the last of which was on July 20, 1991.

Already 92 degrees in Northern Maine before noon. ESTCOURT STATION 4ESE MAWS, ME. ESCM1 (HADS) 18 Jun 11:45 am 92 WSW 1 30.01 30.87 0.00

It will be interesting to see if Caribou can challenge their all-time June high temperature. Burlington recently set their all-time May record high.

Areas that missed the convection are seeing one of their driest mid-May to mid-June periods on record. Bridgeport has picked up less than an inch of rain over the last 30 days. LGA and ISP only have a little more than an inch. Time Series Summary for IGOR I SIKORSKY MEMORIAL AIRPORT, CT Click column heading to sort ascending, click again to sort descending. Rank Ending Date Total Precipitation May 18 to Jun 16 Missing Count 1 1957-06-16 0.63 0 2 2020-06-16 0.75 1 3 1955-06-16 1.15 0 4 1971-06-16 1.16 0 5 1987-06-16 1.19 0 Time Series Summary for LAGUARDIA AIRPORT, NY Click column heading to sort ascending, click again to sort descending. Rank Ending Date Total Precipitation May 18 to Jun 16 Missing Count 1 1967-06-16 0.58 0 2 2020-06-16 1.12 1 3 1944-06-16 1.19 0 4 1994-06-16 1.39 0 5 1965-06-16 1.49 0 Time Series Summary for ISLIP-LI MACARTHUR AP, NY Click column heading to sort ascending, click again to sort descending. Rank Ending Date Total Precipitation May 18 to Jun 16 Missing Count 1 1964-06-16 0.91 0 2 1994-06-16 1.11 0 3 1981-06-16 1.12 0 4 2020-06-16 1.21 1 5 1967-06-16 1.24 0