This weekend is to average 6 degrees warmer than last—any lingering Saturday morning showers to give way to sunshine—Next showers/t-storms are Sunday night, Monday and again Thursday


RECORD NUMBER OF HOURS ABOVE 110 DEGREES FAHRENHEIT HEAT INDEX IN 2023



NOAA INCREASES ITS OUTLOOK OF POTENTIAL 2023 ATLANTIC BASIN HURRICANES

  • A series of factors likely to override the hurricane “dampening” effect of the ongoing and strengthening El Nino in the equatorial Pacific
  • NOAA’S NWS Climate Prediction Center (CPC) in Thursday significantly boosted its prediction of number of tropical cyclones (i.e. “hurricanes” and “tropical storms”) across the Atlantic basin, which includes the Atlantic, Caribbean and Gulf of Mexico over its earlier May forecast. In doing so, NOAA’s latest outlook parallels other major hurricane season forecasts in noting a series of factors which, based on the best available information/observations, likely to override the dampening effect often observed with El Niños—like the one currently in progress across the equatorial Pacific. El Niños, though occurring far from the Atlantic basin, have been shown to be accompanied by INCREASED WIND SHEAR over the Atlantic Basin, a development known to disrupt hurricane formation.
  • The agency has boosted the chance of an ABOVE NORMAL 2023 hurricanes to 60% from 30% in its May forecast. Check out the new outlook’s projected number of storms and the change in these numbers from the agency’s MAY 2023 ATLANTIC HURRICANE SEASON outlook:
    Number of named storms:
    14 to 17 (up from 12 to 17 in May)
    Number of hurricanes:
    6 to 11 (up from 5 to 9 predicted in May)
    Number of MAJOR hurricanes:
    2 to 5 (up from 1 to 4 in May)
  • THIS IS IMPORTANT—NOAA STRESSES IT DOESN’T PREDICTED LANDFALLS in its outlooks, stressing: “NOAA DOES NOT make seasonal hurricane LANDFALL predictions. Hurricane landfalls are largely determined by the weather patterns in place as the hurricane approaches, and those patterns are only predictable when the storm is within several days of making landfall.”

NOTE THAT THE 2023 HURRICANE SEASON HAS ALREADY LOGGED THE FOLLOWING STORMS

THERE ARE UNCERTAINTIES IN MAKING SEASONAL HURRICANE FORECASTS WHICH NOAA LAYS OUT

Sources of uncertainty in the seasonal outlooks

  • Predicting El Niño and La Niña events (also called the El Niño-Southern Oscillation, or ENSO) and their impacts on North Atlantic basin hurricane activity, is an ongoing scientific challenge facing scientists today. Such forecasts made during the spring generally have limited skill, but that skill increases during the summer. Specific to this outlook, the major sources of uncertainty are rooted in the interplay between the current El Niño and the conditions local to the North Atlantic.
  • Many combinations of named storms, hurricanes, and major hurricanes can occur for the same general set of climate conditions. For example, one cannot know with certainty whether a given climate signal will be associated with several shorter-lived storms or fewer longer-lived storms with greater intensity.
  • Model predictions of various factors known to influence seasonal hurricane activity in the Atlantic region, such as sea surface temperatures (SSTs), vertical wind shear, moisture, and atmospheric stability are still showing some spread for August-October (ASO), the peak months of the hurricane season, and it is unclear as to exactly how conducive these conditions will be for tropical cyclone development.
  • Shorter-term weather patterns that are unpredictable on seasonal time scales can sometimes develop and last for weeks or months, possibly affecting seasonal hurricane activity.

  • Perseids meteor shower peaks this weekend with ideal viewing conditions given we’ll be only days from the new moon (which is where the moon all but disappears from view) and therefore only 10% moonlight illumination from the moon, and weather conditions which appear poised to cooperate in Chicago.
  • The Perseids is often described as meteor shower enthusiasts’ favorite of the year, and it reaches its annual peak this weekend: Sunday morning around 3am CDT—though meteors are to be visible at other times. We’re advised the meteors will appear to emanate from the Constellation Perseus which is situated in the northeastern nighttime sky.

NIGHTTIME CLOUD COVER OVER CHICAGO


WILDFIRES ARE NOT NEW TO HAWAII, BUT THERE HAS BEEN NO SET OF FIRES IN RECENT HISTORY OF THE MAGNITUDE OF WHAT’S JUST HAPPENED ON MAUI

The Hawaii Wildfire Management Organization (HWMO) has produced a detailed overview of the wildfire history on the Hawaiian Islands. With the support of the U.S. Forest Service and the University of Hawaii, researchers pored over 13,500 fire records from 2002 to 2012 to produce the following graphic and an analysis of the state’s wildfire history. Interestingly, HWMO notes the clusters of fires adjoining highways.

U.S. DROUGHT MONITOR—HAWAII


IT’S MORE THAN A WEEK OFF, BUT IF A SERIES OF MODEL PROJECTIONS VERIFY, WE COULD BE HEADED FOR SOME FORMIDABLE LATE SEASON HEAT TOWARD NEXT WEEKEND INTO THE WEEK WHICH FOLLOWS

  • Confidence in a forecast scenarios, even eye-catching forecasts like some which have arisen suggesting A FORMIDABLE ROUND OF LATE SEASON WARMTH out in the 1 to 2 week range—grows when, not just one, but a series of model forecast, arrive at similar conclusions. That’s what we see beginning to happen among the machine forecasts toward and beyond next weekend suggesting A HIGHLY EXPANDED DOME OF HOT AIR—the sort of feature which would produce HEAT is to take up residence over the Midwest.
  • At such an extended range in time, this forecast isn’t yet carved in stone. It’s not yet time to bet the farm on this. But it’s going to be interesting to follow forecast developments in the coming week.
  • Performing a bias correction on an “in-house” average of predicted temps off a collection of models and their model runs, suggests this could series a series of 90-degree days could come together beginning next weekend and carrying over into the following week.
  • So what could go wrong with these early projections. The most notable answer is the eruption of t-storm clusters on the periphery of the expanding dome of heat which would slow or reverse its expansion. This happened several weeks ago. But the forecast of heat was as potent as the current set of medium range projections. Of interest too are suggestions the Southwest and Western monsoon may pick up in the 1 to 2 week time range. Such a development has preceded a shift in the position of Southwest hot air domes into the Plains and the Midwest.

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