beavis1729

Extreme warmth over southern AK yesterday. Many locations set all time record highs. Anchorage hit 90. They only hit 80 once every 4 years on average...but by the end of next week, they may have 7-10 80+ days this season already. Southcentral and Southwest Alaska Forecast Discussion National Weather Service Anchorage AK 526 AM AKDT Fri Jul 5 2019 .ANALYSIS AND UPPER LEVELS... It has become a bit of a broken record to talk about the stationary upper-level ridge over the southern mainland and the upper-level trough upstream over the far western Bering; however, this continues to be the synoptic pattern over the forecast area as the upper-level rex block (high pressure north of low pressure) remains firmly in place across the north Pacific. Speaking of broken records, a plethora of daily and all-time records were set across southcentral and southwestern Alaska yesterday as both the ridge and the amount of subsidence (sinking air) reaches peak intensity. More on this in the Climate portion of the discussion. It was not hot and dry everywhere, though, as cooler temperatures prevailed for some coastal locations (e.g. Seward, Whittier, Kodiak), aided by either sea breezes or low stratus and patchy fog. Across the interior, scattered mid- and high-level clouds continue to rotate around the northern periphery of the high, extending from Bristol Bay east across the Alaska Range to the Copper River Basin. Along the coast, the low stratus and fog continue to spread out, with satellite imagery showing extensive low cloud cover moving west over the Barren Islands and along the eastern coastlines of Kodiak Island and the Kenai Peninsula. Farther west, low stratus and fog is also building across the eastern and central Bering and Aleutians in the wake of the slow- moving trough over the western Bering. For places such as Cold Bay and Saint Paul, visibility is reduced due to fog and mist with ceiling of only a couple hundred feet. && .MODEL DISCUSSION... Models are in fairly good agreement on the synoptic features and overall pattern. One forecast challenge to note is that some of the hi-res models, with the HRRR the most bullish, are suggesting the expansion of a band of low stratus over the Barren Islands rounding the southern coast of the Kenai Peninsula and moving north along Cook Inlet in response to an increasing up-inlet flow. Obviously, this scenario would throw a wrench in the cloud cover and temperature forecasts for locations along the inlet, Anchorage included. Confidence in this is rather low, however, as the stratus currently sitting west of Augustine Island overnight as yet to make any northward movement. && .AVIATION... PANC...VFR conditions and light winds will persist. Visibility may be slightly reduced at times through mid-morning as a light southerly wind advects smoke over Anchorage from the Swan Lake fire. The southerly wind is then expected to become westerly around mid-morning, pushing the smoke away from the airport complex. && .FIRE WEATHER... Near-record breaking temperatures will remain a possibility through the weekend as hot and dry conditions persist across southcentral and southwest Alaska. Generally, winds will continue to remain light and variable across interior locations, keeping dense smoke from the Swan Lake fire trapped within the valleys of the Kenai mountains. A southerly flow along the eastern coast of the Kenai Peninsula should help provide some relief, keeping the thickest of smoke north of coastal locations such as Seward through the evening hours. The dense smoke, however, looks to settle back in from Moose Pass south to Seward tonight as a light northerly flow develops. A developing sea breeze and up inlet flow will likewise help to scour out any lingering smoke around Homer this afternoon. Areas of smoke will also continue for locations south and east of the Montana Creek fire with a continued light northerly transport wind. As stated in previous discussions, the smoke may lift a bit during the afternoon and evening hours due to daytime heating and increasing mixing heights. However, continued subsidence and nighttime temperature inversions will also allow the smoke to settle back down and fan out over the Western Kenai and eastern Susitna Valley during the overnight hours. && .CLIMATE... The 4th of July 2019 was a day truly for the record books in the climate department. Numerous high temperature records were set, along with several ALL-TIME temperature records. Here is the list: Site.............Type.......New Record...Old Record (Date/Years) Anchorage Intl...ALL-TIME...90 degrees...85 degrees (Jun 14, 1969) Merrill Field....ALL-TIME...90 degrees...87 degrees (Jun 27, 1953) Palmer...........ALL-TIME...88 degrees...88 degrees (May 27, 2011) Kenai............ALL-TIME...89 degrees...87 degrees (Jun 26, 1953 & 116 year old record!---> Jun 18, 1903) King Salmon......ALL-TIME...89 degrees...88 degrees (Jun 27, 1953) ------------------------------------------------------------------- Anchorage Intl...Daily......90 degrees...77 degrees (1999) Merrill Field....Daily......90 degrees...77 degrees (1999) Palmer...........Daily......88 degrees...81 degrees (1979) Kenai............Daily......89 degrees...75 degrees (2003) King Salmon......Daily......89 degrees...84 degrees (1997) Homer............Daily......78 degrees...71 degrees (2018) Gulkana..........Daily......88 degrees...86 degrees (1958) Iliamna..........Daily......86 degrees...79 degrees (1949) && .SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Days 1 and 2)... Overall hot and dry conditions will continue the next few days. The center of the upper level ridge which brought all-time record highs to a number of locations over southern Alaska yesterday will remain directly overhead today and then begin to edge westward on Saturday. This will produce daily record high temperatures again today and many locations in southern Alaska. Areas inland will likely see temperatures close to what they were yesterday, but areas along Cook Inlet will see increased southwesterly winds which are expected to edge temperatures down slightly from yesterday`s levels, but remain hot. The Jekyll and Hyde nature of Alaska weather can be seen with the way this same high pressure is also causing widespread fog and stratus over the entire Gulf of Alaska. This has caused locations right along the coast to get fog and much cooler temperatures along the north Gulf Coast and eastern Kodiak Island. This fog and stratus will be quite persistent and is not expected to dissipate or move out of the area any time soon. This brings the forecast challenge the next few days for the Cook Inlet region up to and including Anchorage. With this pattern, the stratus usually pushes up Cook Inlet from the Southwest. The uncertainty with this is whether it will be able to do this due to the unusually hot temperatures. Will the temperatures cause enough vertical mixing to keep the inversions from developing strong enough to advect the stratus up the Inlet? Or will the stratus be able to ride the southwest flow up the Inlet (or at least part of it) and drastically drop temperatures in the marine airmass? I am going with the first option as it seems like the most likely situation in light of the past few days. The second scenario is worth watching. && .SHORT TERM FORECAST SOUTHWEST ALASKA (Days 1 through 3: Today through Sunday Night)... Record heat in King Salmon and Iliamna yesterday was caused by an incredibly strong upper level high that is parked over Southcentral. This dome of hot air extends westward across much of Southwest Alaska. With surface high pressure building off the Bering coast, breezy northeast winds are expected to persist across the Kuskokwim Delta today. The hot, offshore winds will allow temperatures across the Kuskokwim Delta to warm into the lower 80s today. Meanwhile further east, winds have diminished a bit across the Lower Kuskokwim Valley and Bristol Bay areas, though temperatures are expected to once again top into the upper 80s to near 90 across the Lower Kuskokwim Valley, with mid to upper 80s expected across Bristol Bay. The upper level high will begin to slowly shift westward this weekend, moving over Southwest Alaska by Sunday afternoon. Fortunately it will also be slowly weakening by this point. The weakening is not expected to do much for high temperatures, which will remain roughly the same across most interior areas through the weekend. Offshore northeasterly winds will continue drying the area out as relative humidity values drop below 30 percent over the Lower Kuskokwim Valley by Sunday. One area that will be bucking the hot temperatures trend will be along the coast. Winds are expected to switch to out of the southwest along Bristol Bay by Saturday afternoon, persisting into Sunday. It will take until late Sunday night for the same to happen over the Kuskokwim Delta. The onshore winds in these areas will be like turning on the air conditioner, keeping high temperatures much more comfortably cool in the 70s by Sunday. The next few afternoons, it will be possible for showers to develop along the area mountains. Any showers may drift off the mountains into the nearby foothills, which will help quite a bit with locally cooling down the temperatures. && .SHORT TERM FORECAST BERING SEA/ALEUTIANS (Days 1 through 3: Today through Sunday Night)... There will be a few weak systems impacting portions of the area. The primary one will be the edge of the upper level high which, while producing offshore winds, will continue pushing most of the marine stratus and fog out away from the coast. The front over the western Bering will continue drifting westward and dissipate later today. A North Pacific low will track well south of the central and eastern Aleutians Saturday and Saturday night. Its northern periphery will skim through the islands, which may locally produce some light rain along with breezy easterly winds. A stronger North Pacific low will approach the western and central Aleutians Sunday afternoon into the overnight, before stalling just south of the islands late Sunday night into Monday morning. && .MARINE (Days 3 through 5)... (Sunday through Tuesday) ...Bering Sea and Aleutian Coastal Waters... High pressure will build westward from southcentral Alaska and influence the northeastern half of the region, with dry conditions expected. Further southwest, an area of low pressure passing along or south of the chain will spread some showers into the region. Otherwise, look for seas less than 10 feet and sustained winds to remain below gales (and possibly small craft as well) area-wide. ...Gulf of Alaska... High pressure will continue to dominate the weather through the period, with winds and waves remaining below small craft conditions. && .LONG TERM FORECAST (Days 3 through 7)... (Sunday through next Thursday evening) The numerical guidance remains in good agreement for Sunday, before quickly diverging in model continuity for Monday and beyond. The main issue seems to be the temporal displacement of the ridge center, with the GFS model being the fastest and furthest northwest, as it has the low over the Seward Peninsula by Monday afternoon. The Canadian model, however, repositions the high pressure center to north of Fairbanks, while the ECMWF takes a middle ground approach and has it centered between Bethel and McGrath. A similar scenario across the southwestern Bering exists, with the GFS the quickest to undercut the ridge, and the other two models slower. The model spread only increases each day after that. In general, we prefer the Canadian solution for the ridge to break down slower, given the lack of any strong mid or upper level disturbances to break down the ridge or displace it as fast as some models suggest. Typically, when one of these weather patterns gets "locked in place" the models struggle with pattern change and are all too often too quick to make said change. This in turn keeps temperatures warmer for a longer period of time. Perhaps the bigger issue is they all agree on several disturbances rounding the top of the ridge, dropping south across Southcentral and into portions of southwest Alaska. Long range instability projections show more than enough instability for at least some thunderstorms to develop, with boosts of ascent accompanying each vort max, in a favored north to northeasterly wind flow, potentially raising wildfire concerns even more. && .AFC WATCHES/WARNINGS/ADVISORIES... PUBLIC...Dense Smoke Advisory: 121. MARINE...NONE. FIRE WEATHER...NONE. && $$ SYNOPSIS AND MODEL DISCUSSION...TM CLIMATE...JPW SOUTHCENTRAL ALASKA...EZ SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...JPW MARINE/LONG TERM...PD

Well, that’s unfortunate. I thought there was no way it could be running cold. If anything, I always thought ORD was a warm spot compared to surrounding areas, especially noting the relatively warm -23F min during the January arctic outbreak. At the same time, I can’t imagine that MDW and PWK are fair comparisons, and they shouldn’t be considered representative of the climo in this area. They both have ridiculous UHI. Although, given how the Chicago metro area continues to develop, we will all be living in an urban wasteland soon anyway.

This came up before. It seems more likely that PWK, MDW, and other nearby areas have a warm bias (or are simply located in an extreme UHI urban jungle near a concrete tarmac)...as opposed to ORD having a cold bias. More evidence is when ORD only hit -23 during the late-January 2019 arctic outbreak, when many other nearby areas were -25 to -30. I'm in SW Lake County and hit 89 yesterday, just like ORD.

Right...and there were 3 years that only had one 90+ day (1882, 1884, 1915). Not sure about 1995; I think it may have had around 30 90+ days? Of course it had the intense heat wave in mid-July, when the heat index hit 125 at Midway. I was working construction that summer, and it was simply brutal. No other way to describe it. It was so warm aloft that there weren’t any clouds at all.

Just saw some 90-degree stats for Chicago on NWS LOT's page. Not intending to be critical...but I think there are a couple of errors. First, where is 2012 in the list? It had 46 90+ days, I believe. Second, the existence of a "latest first" date implies that every year had at least one 90+ day...but I don't believe this is correct. Chicago Normal First Date 90 deg: June 8 Normal Last Date 90 deg: August 28 Earliest First: April 10, 1930 90 degrees Earliest Last: July 1, 1967 90 degrees Latest First: Sept 14, 1915 90 degrees Latest Last: Oct 6, 1963 94 degrees Average Number of Days with High Temperature of 90 Degrees or Higher May June July Aug Sept Annual 0.5 3.0 5.9 3.6 1.0 14 Greatest Number of Days with Maximum Temperature 90 Degrees or Higher in Any Year 1. 47 (1988) 6. 36 (1954) 2. 46 (1955, 1988) 7. 35 (1964, 1971) 3. 42 (1953, 1983) 8. 34 (1944) 4. 39 (1959) 9. 33 (1977, 1987) 5. 38 (1952) 10. 32 (1934) Greatest Number of Days with Max Temperature 90 Degrees or Higher By Month Apr May June Jul Aug Sept Oct 2 (1930) 10 (1977) 16 (1954) 19 (1955,1987) 18 (1947) 9 (1931) 2 (1971)

I visited Yellowstone NP in early June, and stayed in West Yellowstone for a few nights...which is around 7,000' elevation. What a beautiful place. Temps were in the 60s during the day and near freezing at night...with late afternoon showers as the clouds formed over the mountains. Their average annual snowfall is around 150", with most years having continuous snow cover for 6 months (Nov through April). Normal low is around 0F during DJF.

Miami FL hit 98 yesterday, which tied the all-time monthly high for June. And, this is only the 11th time on record that Miami has hit 98 or higher. All-time record high is 100 on 7/21/1942.

While the relatively cool weather continues here, the southern plains are baking. Laredo TX hit 109 yesterday, with a peak hourly heat index of 116 (temp 107, dew 69). And, today will set a daily record high min of 83 (old record 82 in 2011).

Interesting...I'm honestly surprised that there are so many instances where it has taken so long for the first 85+ temp. With that said, I don't really put too much stock in the 1800s records, since the ob site was so close to Lake Michigan and it was a different climate regime (not to digress too much...but if you look at Chicago's daily record low max temps from mid-May through June, almost all of them are from the 1800s). Anyway, I think there's a good chance that ORD makes it past June 23...in which case 2019 would have the 4th latest first 85+ temp on record...and the latest since 1935.

The 2019 high temp at ORD so far is only 83, on June 5th. And, it should hold for at least a few more days.

Yeah, crazy stuff. Up to 50 at 2 pm. Looks like South Bend had a midnight high of 58, so it will go down as the 2nd coldest max on record for the date. Their record low max for 6/13 is actually much colder than I thought it would be (53 in 1955); definitely a cold outlier compared to the dates around it, which are generally in the upper 50s.

Interesting that ORD has only had 4 days with high temps of 82+ so far in 2019, with zero days of 84+. Not sure what the average # of 82+ days is for ORD by June 13th in any given year, but it has to be significantly higher that what we've seen in 2019. Normal high this time of year is 80, but it ramps up quickly to 85 by the end of June. Strangely enough - despite all of the whining about how chilly it has been this Spring, the overall mean temp for the period April 1st - June 13th at ORD has been essentially normal. Just not a lot of excessively cool or warm days. To me, this apparent contrast illustrates that it's still fairly early in the warm season for NE IL, given the lake influence. I generally consider "consistent summer" at ORD to be June 10th - Sep 10th, as opposed to May 15th - Sep 10th in other areas of IL away from the lake. No complaints from me; even with the excessive rainfall, temps have been fairly pleasant in May/June so far.

Welcome, and good question. You can find cooler summers in northern WI, even away from the moderating effects of Lake Michigan. Many places north of Wausau have normal highs 75-80 and normal lows in the 50s, even in the heart of summer. This compares to July normals in Chicago of 85/65...and, if anything, downtown is even warmer at night due to UHI and lake temps that are much warmer compared to May/June. Any significant cooling impact from Lake Michigan is generally limited to April through early June. After that, the water temp is high enough where the cooling isn't as noticeable (it's less severe and/or less frequent). As Hoosier said, small lakes don't generally have a significant impact...mainly due to the small size and the fact that smaller bodies of water heat up faster than larger ones. In July and August, there is essentially zero lake cooling, because prevailing winds often come out of the W or SW instead of W/NW/N/NE...and because water temps are warm enough where the lake cooling just isn't very noticeable. And in September/October, there is a warming effect due to the warm lake temps...compared to air temps that are beginning the seasonal decline. Just my 2 cents...although I could be off on some of the details.

Cheyenne, WY just saw 9.9" of snow over the past 3 days (May 19-21), with a snow depth of 8" this morning. I know they're at 6,000 ft elevation...but that is just shocking to me. The high temp on 5/21 was only 34; normal high is 67. Average annual snowfall is 60", but they've had 82" this season.

Looks like 8-12" in the Cheyenne area...crazy.

Duluth had 2.4" of snow yesterday (5/19). While this is the heaviest snowfall on record for so late in the season, you could argue that there have been a couple of more impressive snowfalls even later. Here are all calendar day snowfalls of 0.5"+ for DLH, on or after 5/19: 5/19/2019: 2.4" 5/19/1971: 0.6" 5/23/1924: 0.5" 5/27/1932: 2.0" 5/27/1965: 0.6" Latest measurable snowfall is 0.4" on 5/28/1965.

Saturday had a lot of changing/variable sky conditions over N IL and S WI...so it's understandable that temps over the region weren't as uniform as usual. MBY only hit 73, as we only had a few small breaks of sun during the afternoon.

The first day of the arctic outbreak (Jan 30th) was purely advection-driven, given the strong winds and CAA. In that situation, UHI doesn't matter as much. ORD hit -23, and most areas in N IL were similar. And RFD was actually colder, at -25. So, no cold bias there. On the second day (Jan 31st), ORD ended up being much warmer than you'd expect, not colder. Definitely not a cold bias. ORD only hit -21, whereas many areas of N IL were -25 to -30. RFD hit -31, and MLI -33...and Mt. Carroll set a new all-time IL record low at -38. MBY was -27. The details were discussed extensively in the arctic outbreak thread.

Agree that PWK seems to have a warm bias. You’ll see this on low temps too, in addition to highs. It’s as if the jet exhaust at Palwaukee Airport is hitting the thermometer. The UHI around there is bad, but not *that* bad...

Yeah, agree that a bit of snow looks possible for you tomorrow! Have you ever had flakes in the air as late as May 19th? Parts of SW ND actually saw 2-4” of snow today and were under a WWA...crazy.

Wow!! Did you have any snowpack left before today?

That makes it Chicago's heaviest snow on record so late in the season. 2nd place is May 1-2, 1940 (2.2"). Had about 3" here on cold metal surfaces, 2" on grass, and 1" on pavement. At 10 PM Saturday night 4/27 with snow caked on all surfaces and tree branches, it truly looked like a winter wonderland. By 6 AM the next morning, the snow on paved surfaces melted from below, despite temps around 28-30 overnight. By noon, all of the snow was gone.

I will be the first to admit and defend my high standards for winter...but even I must say that today is incredible. Never in my life have I seen a true winter wonderland this late in the season. Currently 32 with twilight fading to darkness at 7:26 PM on April 27th and about 1.5” on grass and trees with moderate snow falling...and a dusting on pavement. Heck, the normal high in Fairbanks AK for today is 52. It really is amazing.

ORD and RFD have a chance for record lows tomorrow. Record is 28, set in 1992 and 1976, respectively.

Magic number for ORD is 2.3”. That would make it Chicago’s largest snowfall on record so late in the season. I think it will fall a bit short, but we’ll see.