The Map Gets “Flatter,” the Confidence Grows Lower

June 2nd, 2014 at 9:50 pm by under 4 Warn Weather

As we’re now into the warm weather season, the surface features on the weather map tend to be flatter and weaker, as do many of the mid-level features aloft. In other words, timing weaker more subtle systems makes for some challenging forecasting. That doesn’t mean ALL systems are weak and poorly defined. In fact, as I type this post conditions look favorable for a rather major Severe Weather Outbreak on Tuesday the 3rd over portions of Iowa, Minnesota, Nebraska, NE Kansas and west central Illinois. But in the mean, defining troughs and ridges in the 500 mb flow, properly placing them, and properly determining their strength/amplitude becomes tougher. That’s because the mean tends to produce more of a zonal look. That’s in contrast to the blocky, high amplitude pattern we had so often until recently.

And remember, this mean is often the smoothed mean of many ensemble members in the global models which have a lot of spread between one another. The mean can be a best choice by default. But it is not necessarily the most reliable choice.

There will be a cooldown with reduced humidity returning toward Wednesday morning. Almost immediately afterward, there is already low confidence as to when any showers associated with an area of low pressure going by to our south might arrive in parts of WNY, with 2 operational models bringing those showers back in by mid or late Wednesday afternoon. Odds do favor much of the rain with that system staying farther south. The GFS is blindingly fast with onset and exit times, and viewed with suspicion on that speed. After lovely and dry days on Friday and Saturday, during Sunday another area of low pressure will be approaching, probably bringing some convection in by later in the day, with a few more rounds into Monday AM. There are no signs of prolonged heat and humidity, nor are there signs of prolonged cool weather. So, at this point, much of this next weekend looks pleasant. But unlike the last 2 weekends, the finish to the weekend is in doubt.

There are no changes to the ENSO forecast this week. The so-called key Nino Region 3.4 has a +.6 degree positive SST anomaly. Generally, an el nino is not considered as such unless there are 3 consecutive months of el nino conditions. A couple of weeks doesn’t cut it, partially due to the rising and ebbing warming/cooling caused by Kelvin waves traversing the Pacific. I’m still seeing only a handful of ENSO models projecting a truly strong el nino. Many, including the mean of the CFSv2, lean toward a moderate el nino.

98 Responses to “The Map Gets “Flatter,” the Confidence Grows Lower”

  1. Don Paul says:

    2pm PWATs/Precipitable Water from SPC:

    http://www.spc.noaa.gov/sfctest/new/viewsector.php?sector=16#

    1.6″ from KBUF north to Lk Ontario. BUT you still need some boundaries/triggers to capitalize on the available moisture. Some solar insulation should help fire up more Sct convection late today and this evening. Stronger storms are well to the NE, with the warm front now just north of Buffalo.

  2. Dave from Roc says:

    Don – It seems the higher precip numbers favor hilly areas well south, and also well to the north over lake Ontario and into Canada. Is downsloping on a southerly flow contributing to this pattern, or is it more about the position of larger scale frontal boundaries?

    By the way, just another reminder to any folks traveling into the ROC area… continue to be extremely vigilant, as the incidents continue to come in, and are becoming more serious:

    http://www.rochesterhomepage.net/story/d/story/school-bus-has-been-struck-by-what-appears-to-be-a/21484/nnlm8agiXU2YS990Z3j0AQ

  3. LisaZ says:

    Looks like storms are starting to flare up to the SW, some smaller cells just south of Buffalo, so activity does appear to be on the increase. Widely scattered though as Don forecasted yesterday.

  4. Don Paul says:

    Synopsis & forecast:

    The passage of this morning’s warm front with its showers and cloud cover have temporarily stabilized the atmosphere over WNY. But in the late afternoon, some partial clearing is allowing more heating in this humid airmass, and that will make the air more “bubbly” or unstable. Scattered showers are moving up from PA, and some will develop into Sct Tshowers, any one of which could produce locally heavy downpours. Coverage will be very uneven and spotty, rather than widespread. Temperatures will range from the upper 70s to low 80s, with a modest SSW breeze of 12-18, lighter to the south. It is cooler along the immediate Lk Ontario shoreline below the escarpment. Tonight will be Muggy with more Sct & Occ’l Shwrs & Tshwrs, with a few possible downpours during the evening. There will be rainfree periods as well. This Muggy air mass will stay in place into early Friday, with several more rounds of Sct Shwrs & Tshwrs. Thursday may bring a few isolated Stronger Tstorms during afternoon heating. A cold front will cross the region during Friday, with spotty shwrs & tshwrs winding down from W to E. Drier air will begin to filter in later Friday, with much better “sleeping weather” returning for Friday and Saturday nights. Dry air & abundant sunshine will make for a lovely Saturday for outdoor activities. A more southerly flow will return during Sunday, bringing temps up along with comfortable but moderate humidity. Saturday will be the more comfortable day to wander among the crowds at the Allentown Arts Festival and the Juneteenth Festival. By Monday morning, humidity will be edging back up with the approach of another warm front. Monday will be nearly Sultry, with some Sct Shwrs & Tshwrs developing for a portion of the day. The Muggy airmass will last at least into Wednesday with several rounds of showers & tshowers, and only limited sunshine. There are signs a somewhat more comfortable air mass will return later next week.

    THIS AFTERNOON: Limited Sunshine & Muggy, with at least a few Sct Shwrs & Tshwrs developing from the SSW toward the NNE. Any tshwrs could produce local downpours, though coverage will be spotty. High: mid 70s immediate lakeshore-low 80s inland. SSW 12-18, lighter s tier.

    TONIGHT; Muggy with Sct & Occ’l Shwrs & Tshwrs, along with some rainfree periods. A few spotty evening downpours will be possible. Low: 63 valleys-68.

    THURSDAY; Mostly Cloudy & Muggy with Sct & Occ’l Shwrs & Tshwrs. Some isolated stronger Tstorms will be possible PM. Again, coverage will be spotty. High: upper 70s-low 80s. Spotty shwrs & tshwrs gradually diminish in coverage overnight. Still Muggy. Low: 63-66.

    FRIDAY; Mostly to Partly Cloudy with a few shwrs & possible tshwrs AM, becoming Partly Sunny mid/late afternoon, with any showers winding down. Humidity will begin to drop back later in the day. High: mid 70s.SW/WNW 10-17. Cooler & Less Humid overnight. Low: mid 50s.

    SATURDAY; Mostly Sunny & Pleasant, with Low Humidity/High UV. High: 73. Low overnight: low 50s.

    SUNDAY; Mostly Sunny & Warmer, with moderate humidity PM. High: 80.

    MONDAY; Partly Cloudy, Warm & More Humid with some Sct Shwrs & Tshwrs becoming more likely. High: 83. Muggy overnight.

    TUESDAY; Limited Sun, Warm & Humid with Sct Shwrs & Tshwrs. High: 81. Muggy overnight.

    WEDNESDAY; Mostly, then Partly Sunny & Warm, with possible Sct Shwrs & Tshwrs. High: 80.

  5. Don Paul says:

    A monthly global satellite-derived temperature report from the U of Alabama at Huntsville’s Earth Science Laboratory:

    Vol. 24, No. 2

    For Additional Information:
    Dr. John Christy, (256) 961-7763
    john.christy@nsstc.uah.edu
    Dr. Roy Spencer, (256) 961-7960
    roy.spencer@nsstc.uah.edu

    Third warmest May in satellite record
    might portend record-setting El Niño

    Global Temperature Report: May 2014

    Global climate trend since Nov. 16, 1978: +0.14 C per decade

    May temperatures (preliminary)

    Global composite temp.: +0.33 C (about 0.59 degrees Fahrenheit) above 30-year average for May.

    Northern Hemisphere: +0.33 C (about 0.59 degrees Fahrenheit) above 30-year average for May.

    Southern Hemisphere: +0.33 C (about 0.59 degrees Fahrenheit) above 30-year average for May.

    Tropics: +0.17 C (about 0.31 degrees Fahrenheit) above 30-year average for May.

    April temperatures (revised):

    Global Composite: +0.19 C above 30-year average

    Northern Hemisphere: +0.36 C above 30-year average

    Southern Hemisphere: +0.02 C at 30-year average

    Tropics: +0.09 C at 30-year average

    (All temperature anomalies are based on a 30-year average (1981-2010) for the month reported.)

    Notes on data released June 11, 2014:

    May 2014 was the third warmest May in the 35-year satellite-measured global temperature record, and the warmest May that wasn’t during an El Niño Pacific Ocean warming event, according to Dr. John Christy, a professor of atmospheric science and director of the Earth System Science Center at The University of Alabama in Huntsville. The global average temperature for May was 0.33 C (about 0.59 degrees Fahrenheit) warmer than seasonal norms for the month. The warmest May was in 1998, during the “El Niño of the century.” Temperatures in May 1998 were 0.56 C (about 1.0 degrees F) warmer than normal. May 2010 — also an El Niño month — was second warmest at 0.45 C (0.81 degrees F).

    While May 2014 was not officially an El Niño month, indications are that an El Niño is forming in the eastern central Pacific off the equatorial coast of South America. Even if that El Niño is nothing spectacular, it might become a record setter simply because it is getting a warmer start, Christy said. “The long-term baseline temperature is about three tens of a degree (C) warmer than it was when the big El Niño of 1997-1998 began, and that event set the one-month record with an average global temperature that was 0.66 C (almost 1.2 degrees F) warmer than normal in April 1998.”

    January through August of 1998 are all in the 14 warmest months in the satellite record, and that El Niño started when global temperatures were somewhat chilled; the global average temperature in May 1997 was 0.14 C (about 0.25 degrees F) cooler than the long-term seasonal norm for May.

    “With the baseline so much warmer, this upcoming El Niño won’t have very far to go to break that 0.66 C record,” Christy said. “That isn’t to say it will, but even an average-sized warming event will have a chance to get close to that level.”

    Compared to seasonal norms, the coldest place in Earth’s atmosphere in May was over the northern Pacific Ocean, where temperatures were as much as 2.08 C (about 3.74 degrees Fahrenheit) cooler than seasonal norms. Compared to seasonal norms, the warmest departure from average in May was along the western border of Kazakhstan. Temperatures there were as much as 4.18 C (about 7.52 degrees Fahrenheit) warmer than seasonal norms.

    Archived color maps of local temperature anomalies are available on-line at:

    http://nsstc.uah.edu/climate/

    As part of an ongoing joint project between UAHuntsville, NOAA and NASA, Christy and Dr. Roy Spencer, an ESSC principal scientist, use data gathered by advanced microwave sounding units on NOAA and NASA satellites to get accurate temperature readings for almost all regions of the Earth. This includes remote desert, ocean and rain forest areas where reliable climate data are not otherwise available.

    The satellite-based instruments measure the temperature of the atmosphere from the surface up to an altitude of about eight kilometers above sea level. Once the monthly temperature data is collected and processed, it is placed in a “public” computer file for immediate access by atmospheric scientists in the U.S. and abroad.

    Neither Christy nor Spencer receives any research support or funding from oil, coal or industrial companies or organizations, or from any private or special interest groups. All of their climate research funding comes from federal and state grants or contracts.

  6. Don Paul says:

    A Severe Thunderstorm WARNING is in effect for Southern McKean County PA until 9:30pm. Severe Tstorms are racing NE at 45 mph, and are capable of producing quarter-sized hail and gusts to 70 mph. If these storms maintain their intensity, they could become a threat to parts of the S Tier. Stay tuned for updates on News 4 and on wivb.com

  7. Don Paul says:

    NEW THREAD IS UP.

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