Some thunderstorms in a generally quiet week...

Posted July 28th, 2010 by Bill Kardas. 67 comments

After the weekend's deludge, we've turned a corner in our weather pattern.  Three beautiful, sunny days in a row are a treat any time of the year here in Central New York, especially in the warm season.  You can thank high pressure for the nice weather we've had lately, but it will be coming to a brief end tonight. 

Summary:  A cold front will sweep through the area tonight, bringing showers and storms this evening and overnight.  As of this morning's data, the most likely time for the storms to develop between 8pm-11pm across Central New York.  You'll want to check back with us later today in case that changes.  The chance of severe weather is low, but some thunderstorms could produce gusty winds.

Discussion:
Ahead of the cold front, winds will switch into the southwest.  This will draw in (advect) warm, somewhat humid air into Central New York.  The airmass being advected into the area is not as humid as it typically is this time of year.  So, dewpoints are expected to rise only into the mid 60s today.  We'll have to keep a close eye on this number, because we've seen a marine influence off of the Great Lakes over the past few days.  There are three things that are needed to cause strong thunderstorms: instability, wind shear, and a trigger.  Lets take a look at each of these in more detail...

Trigger

The timing of the front brings it through CNY close to midnight.  This is not an ideal time for severe weather, because by that point the heating of the day is long over.  Thunderstorms thrive on heat and humidity, and there is almost always less of that at night than during the day.

Instability

This is a look at the forecasted CAPE for 06z, close to the timing of the front.  CAPE values are between 500-750j/kg in CNY...which is enough to generate or maintain storms but not enough for widespread severe weather.  The lifted index shows an axis of instability along the front at 06z.  A look at the 00z CAPE shows high instability values west, with little here in CNY.  Going by this data alone, the storms would move in well after midnight, but the GFS suggests that things could move a bit faster.

Wind shear

Here's a look at the sounding during the frontal passage (midnight).  There is a decent signiture of speed shear (wind speed increasing with increasing height), but no directional shear.  This is called unidirectional wind shear.  Storms in this scenario have a low probability of rotation, thus supercell storms are unlikely.  Storms could produce straightlined winds in a sounding like this, with perhaps some bow lines forming on the radar at times.  Also of note, temperatures stay warm in the upper levels of the atmosphere, which significantly reduces the potential for large hail.

Putting it all together...

The strongest storms today are forecasted to develop west of Central New York.  The front will pass through earlier to the west, during the peak heating of the day (meaning higher instability).  Our chances of severe weather will come from the leftovers of these storms.  With the front approaching the area after dark, these storms will lose some strength before they get here.  Any storms that do make it into Central New York will be weaker, but still able to produce thunder, lightning, and some wind.  The chances for large hail are also low, as the upper level temperatures will be too warm.  We are not concerned about supercell thunderstorms or textbook tornadic activity, as the soundings show unidirectional wind shear.

As always, we'll keep you posted on the latest developments throughout the day.
 

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  1. Bill Kardas (WKTV):

    Please make sure you read the article above (or at least the summary) before posting any questions.

    Posted July 28th at 11:03 AM

  2. Jmd (Fonda):

    Thank you Bill for a VERY informative article for us general weather enthusiasts…I will bookmark this for future reference as it certainly contains all necessary information….(although I’m not “getting” the sounding information…but that’s just me!) Love the visuals you added; they really help to interpret the terminology….Great job!!!

    Posted July 28th at 11:41 AM

  3. Becky (West Leyden):

    Yeah, The severe stuff will be focused over Ohio, western New York and northwestern Pennsylvania. The line will most likely fall apart before it gets to us. However, we will be on the edge, so I guess, a couple of strong one’s could sneak in.

    Posted July 28th at 12:10 PM

  4. Bill Kardas (WKTV):

    JMD,

    Soundings are pretty complicated. It takes a while for students studying meteorology to get the full grasp behind these…but the general idea is that a sounding takes a vertical snapshot of the atmosphere (this case, midnight on Thursday for Rome).

    Here’s a little help: the bottom of the graph represents the ground, and the higher up the chart represents higher altitude. The red line represents temperature changing with height, with the green line representing dew point (humidity). The lines on the right are wind barbs, which represent wind direction and speed. The colors and numbers are the speed, and the direction the lines are pointing represent direction (in today’s case they are all pointing to the left…a west wind).

    Posted July 28th at 12:10 PM

  5. Becky (West Leyden):

    JMD, to add to what BIll said, Soundings often contain SKEW-T indices along the right side that gives a lot of info to help make a forecast.

    Posted July 28th at 12:16 PM

  6. JmD (Fonda):

    Thank you both, Bill and Becky. I do have one question about last Saturday’s storms and the Bulk Richardson Number….one number mentioned was “20”. At that time, I checked the SPC hourly Meso Analysis and for my area it looked like “40”. Can I assume the higher the number, the more severe storms? Or vice versa?

    Posted July 28th at 2:25 PM

  7. Becky (West Leyden):

    JMD, there is no exact interpretation of BRN. (Welcome to meteorology) Different combinations of CAPE and shear can have the same BRN values. Therefore, BRN can represent several convective situations. However, in general, values in the range of 10 to 45 suggest environmental conditions favorable for supercell development. BRN is a way of showing the balance between CAPE and shear.

    >45 CAPE much higher than SHEAR- often pulse storms if CAPE is weak to moderate

    <45 Supercells possible

    <10 SHEAR much higher than CAPE

    Here is a site where you can calculate the BRN. (Unless you want to do the calculus).

    http://www.skystef.be/calculator-bulkrichardson.htm

    Posted July 28th at 3:26 PM

  8. Rob (Whitesboro):

    Looks like there’s a big storm just north of the TUG. Just went through Carthage with strong winds.

    Posted July 28th at 6:27 PM

  9. fairfield:

    dewpoint now creeping up, 77/74

    Posted July 28th at 6:31 PM

  10. Adam Musyt:

    That storm on the Tug may just graze far Northern Herkimer County.

    SEVERE THUNDERSTORM WARNING
    NATIONAL WEATHER SERVICE ALBANY NY
    628 PM EDT WED JUL 28 2010

    THE NATIONAL WEATHER SERVICE IN ALBANY HAS ISSUED A

    • SEVERE THUNDERSTORM WARNING FOR...
    NORTHERN HAMILTON COUNTY IN EASTERN NEW YORK... NORTHERN HERKIMER COUNTY IN EASTERN NEW YORK...

    • UNTIL 730 PM EDT

    • AT 622 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
    LINE OF SEVERE THUNDERSTORMS CAPABLE OF PRODUCING DAMAGING WINDS IN EXCESS OF 60 MPH. THESE STORMS WERE LOCATED ALONG A LINE EXTENDING FROM 30 MILES NORTHWEST OF BIG MOOSE TO 23 MILES NORTHWEST OF BIG MOOSE TO 38 MILES WEST OF OLD FORGE...AND MOVING EAST AT 60 MPH.

    • SEVERE THUNDERSTORMS WILL BE NEAR...
    OLD FORGE BY 655 PM EDT... ALGER ISLAND PUBLIC CAMPGROUND AND BIG MOOSE BY 700 PM EDT... LIMEKILN LAKE CAMPGROUND...INLET AND EAGLE BAY BY 705 PM EDT... EIGHTH LAKE CAMPGROUND...BROWN TRACT POND CAMPGROUND AND RAQUETTE LAKE BY 710 PM EDT... GOLDEN BEACH CAMPGROUND BY 715 PM EDT...

    PRECAUTIONARY/PREPAREDNESS ACTIONS...

    IF ON OR NEAR LAKES IN THE WARNING AREA...GET OUT OF THE WATER AND MOVE
    INDOORS OR INSIDE A VEHICLE. REMEMBER...LIGHTNING CAN STRIKE OUT TO
    15 MILES FROM THE PARENT THUNDERSTORM. IF YOU CAN HEAR THUNDER...YOU
    ARE CLOSE ENOUGH TO BE STRUCK BY LIGHTNING. MOVE TO SAFE SHELTER
    NOW. DON’T BE CAUGHT ON THE WATER IN A THUNDERSTORM!

    PLEASE REPORT HAIL SIZE...DAMAGING WINDS AND REPORTS OF TREES DOWN TO
    THE NATIONAL WEATHER SERVICE BY EMAIL AT ALB.STORMREPORT@NOAA.GOV.

    Posted July 28th at 6:32 PM

  11. Rob (Whitesboro):

    Yeah that’s a pretty intense storm. Almost looks like it has a small hook with it. It’s hard to tell as its right around the radar site.

    Posted July 28th at 6:44 PM

  12. fairfield:

    just started raining here

    Posted July 28th at 7:59 PM

  13. Adam Musyt:

    Small hail possible in the cell just north of Rome. Heavy rain falling now at Griffiss.

    Posted July 28th at 8:22 PM

  14. fairfield:

    thunder here

    Posted July 28th at 8:26 PM

  15. Chris ( HP Weather Observer ):

    Heavy thunder shower here.. winds picked up a bit to maybe a 20 to 25 mph wind gust.. hard to say. Heard a few pings against the glass but no sizeable hail.. just lasted a few seconds.. Strong ling west of syracuse heading east

    Posted July 28th at 8:36 PM

  16. Sar:

    Adam—-is the front anywhere near us?

    Posted July 28th at 8:36 PM

  17. Chris ( HP Weather Observer ):

    Sar.. front is near buffalo no heading east

    Posted July 28th at 8:37 PM

  18. Adam Musyt:

    A brief downpour just ended here.

    #16,

    Front is now crossing Georgian Bay and the state of Michigan, extending back to about Chicago.

    Posted July 28th at 8:38 PM

  19. Chris ( HP Weather Observer ):

    Sar.. correction the front is ear southern michigan.. the line of storms is way out ahead of the front..

    Posted July 28th at 8:39 PM

  20. Adam Musyt:

    Radar shows the thunderstorm on the Oneida/Oswego line near Camden capable of producing 1/2” hail.

    Posted July 28th at 8:57 PM

  21. Matt (Cold Brook):

    Looks like the line west of us is getting bigger.So much for loosing energy after dark.This last one was pretty quiet.
    I feel sory for the people at the Boonville Fair.

    Posted July 28th at 9:06 PM

  22. Mel (Westernville):

    No hail here so far – left rome half hour ago and by the time we got here the roads were dry under the trees.

    Posted July 28th at 9:07 PM

  23. fairfield:

    already .23” of rain, coming in spurts and falls heavy and fast

    Posted July 28th at 9:12 PM

  24. MG(Point Rock):

    Heavy rain, no hail here at this point. Rain letting up at this time

    Posted July 28th at 9:20 PM

  25. Becky (West Leyden):

    Getting heavy rain and a little thunder.

    Rob, I was between Montague and Turin when that storm came though around 6:40 pm, the only thing I saw was that it had a slight rotation to it

    Posted July 28th at 9:22 PM

  26. matt (utica):

    watching the storm from north utica, looks pretty cool- lots of lightning, and can hear thunder. raining on and off too. should be entertaining at least.

    Posted July 28th at 9:24 PM

  27. Adam Musyt:

    SEVERE THUNDERSTORM WARNING
    NATIONAL WEATHER SERVICE BINGHAMTON NY
    932 PM EDT WED JUL 28 2010

    THE NATIONAL WEATHER SERVICE IN BINGHAMTON HAS ISSUED A

    • SEVERE THUNDERSTORM WARNING FOR...
    NORTHWESTERN CHENANGO COUNTY IN CENTRAL NEW YORK... NORTHERN CORTLAND COUNTY IN CENTRAL NEW YORK... SOUTHWESTERN MADISON COUNTY IN CENTRAL NEW YORK...

    • UNTIL 1015 PM EDT.

    • AT 929 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
    LINE OF SEVERE THUNDERSTORMS CAPABLE OF PRODUCING DAMAGING WINDS IN EXCESS OF 60 MPH. THESE STORMS WERE LOCATED ALONG A LINE EXTENDING FROM PREBLE TO CORTLAND...AND MOVING EAST AT 45 MPH.

    • SEVERE THUNDERSTORMS WILL BE NEAR...
    SOLON BY 938 PM EDT... CUYLER BY 942 PM EDT... TAYLOR BY 948 PM EDT... PITCHER BY 950 PM EDT... ERIEVILLE BY 954 PM EDT... ERIEVILLE...OTSELIC AND GEORGETOWN BY 956 PM EDT...

    WHEN YOU CAN DO SO SAFELY...PLEASE REPORT HAIL...OR DAMAGING WINDS TO
    THE NATIONAL WEATHER SERVICE BY CALLING TOLL FREE AT
    1-877-633-6772…OR BY EMAIL AT BGM.STORMREPORT@NOAA.GOV.

    PRECAUTIONARY/PREPAREDNESS ACTIONS...

    IF YOU ARE IN THE PATH OF THIS STORM...SEEK SHELTER INDOORS AND STAY
    AWAY FROM WINDOWS!

    Posted July 28th at 9:35 PM

  28. matt (utica):

    severe tstorm warning just issued for utica.

    going to be a busy night. time to go watch :D.

    Posted July 28th at 9:35 PM

  29. Adam Musyt:

    SEVERE THUNDERSTORM WARNING
    NATIONAL WEATHER SERVICE BINGHAMTON NY
    933 PM EDT WED JUL 28 2010

    THE NATIONAL WEATHER SERVICE IN BINGHAMTON HAS ISSUED A

    • SEVERE THUNDERSTORM WARNING FOR...
    SOUTHEASTERN ONEIDA COUNTY IN CENTRAL NEW YORK...

    • UNTIL 1000 PM EDT.

    • AT 929 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
    LINE OF SEVERE THUNDERSTORMS CAPABLE OF PRODUCING DAMAGING WINDS IN EXCESS OF 60 MPH. THESE STORMS WERE LOCATED ALONG A LINE EXTENDING FROM HINCKLEY TO WESTMORELAND...AND MOVING SOUTHEAST AT 40 MPH.

    • SEVERE THUNDERSTORMS WILL BE NEAR...
    NEW HARTFORD AND UTICA BY 940 PM EDT... WATERVILLE BY 942 PM EDT... CLAYVILLE BY 948 PM EDT...

    WHEN YOU CAN DO SO SAFELY...PLEASE REPORT HAIL...OR DAMAGING WINDS TO
    THE NATIONAL WEATHER SERVICE BY CALLING TOLL FREE AT
    1-877-633-6772…OR BY EMAIL AT BGM.STORMREPORT@NOAA.GOV.

    PRECAUTIONARY/PREPAREDNESS ACTIONS...

    IF YOU ARE IN THE PATH OF THIS STORM...SEEK SHELTER INDOORS AND STAY
    AWAY FROM WINDOWS!

    Posted July 28th at 9:36 PM

  30. Mike(Rome):

    Wow, quite the light show that just blew through Rome. Strong winds and torrential rain along with almost constant lightning.

    Posted July 28th at 9:40 PM

  31. jessie :

    waiting on the storm been outside watching the light show and then it started thundering out and i came in now its a waiting game temps are 74/68

    Posted July 28th at 9:44 PM

  32. Adam Musyt:

    Heavy rain just starting here, along with occasional lightning. Not much wind, at least not yet here at the station.

    Posted July 28th at 9:47 PM

  33. jessie :

    this came on my phoen at 940 passing it along

    STRONG THUNDERSTORMS IN

    SOUTHERN HAMILTON COUNTY IN EASTERN NEW YORK... WESTERN MONTGOMERY COUNTY IN EASTERN NEW YORK... SOUTHERN AND CENTRAL HERKIMER COUNTY IN EASTERN NEW YORK... WESTERN FULTON COUNTY IN EASTERN NEW YORK...

    AT 921 PM EDT... NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A LINE OF THUNDERSTORMS CAPABLE OF PRODUCING... WINDS AROUND 50 MPH... AND HEAVY RAIN. THESE STORMS WERE LOCATED ALONG A LINE EXTENDING FROM COLD BROOK TO 20 MILES WEST OF NORTHWOOD TO 27 MILES WEST OF CEDARVILLE... OR ALONG A LINE EXTENDING FROM HINCKLEY TO 17 MILES NORTHWEST OF UTICA TO 20 MILES WEST OF UTICA... AND MOVING EAST AT 45 MPH.

    THUNDERSTORMS WILL BE NEAR... POLAND AND COLD BROOK BY 945 PM EDT CEDARVILLE... NEWPORT... MIDDLEVILLE AND ILION BY 950 PM EDT MOHAWK AND HERKIMER BY 955 PM EDT JORDANVILLE AND LITTLE FALLS BY 1000 PM EDT

    Posted July 28th at 9:48 PM

  34. Adam Musyt:

    High wind gust to 26 mph at RME.

    Posted July 28th at 9:50 PM

  35. John (Ohio):

    Just came through here, lots of noise, although a bit to the South, lightening (did not appear to be cloud to ground) and heavy rain, no wind though

    Posted July 28th at 9:50 PM

  36. Chris (hp weather observer):

    storm just blew through here, heavy rain thunder and lightning. winds were strong and quite a light show.. still raining pretty good

    Posted July 28th at 9:51 PM

  37. Mike (Northern Utica):

    This one’s a bust. Got my hopes up too. Barely any rain, no wind, some lightning and light thunder. Still very humid my way.

    Posted July 28th at 9:52 PM

  38. jessie :

    i just looked on radar and i see that the storm looks to be getting smaller as it comes towards me again i just want the humidity to drop whens the front supose to be pushing through if any one knows i would appreciate the answer thanks guys for all the hard work you guys dont hear that enough for what you do for are community

    Posted July 28th at 9:55 PM

  39. John (Ohio):

    Just got the wind, nothing severe or over 20 mph however. Just over an inch of rain so far.

    Posted July 28th at 10:01 PM

  40. Adam Musyt:

    Jessie,

    The front will cross the area between 2 AM and 5 AM. Dew point levels will fall through the 60’s after the frontal passage. Dew points will likely fall below 60 sometime tomorrow afternoon.

    Posted July 28th at 10:02 PM

  41. Becky (West Leyden):

    It’s 71/69 here

    Posted July 28th at 10:06 PM

  42. fairfield:

    70/70 here

    Posted July 28th at 10:13 PM

  43. Becky (West Leyden):

    I’ve been trying with no success to find wind reports with that Bow that came through Lewis, Jefferson, and southern St. Lawrence counties a few hours back. Has anyone heard how high the winds got?

    Posted July 28th at 10:22 PM

  44. Adam Musyt:

    Becky,


    All I found from the NWS LSR was "thunderstorm wind damage". There was a report of a 60 mph wind gust near Rome around 9:30 PM.

    Posted July 28th at 10:56 PM

  45. Becky (West Leyden):

    Adam thanks, There must have been at least some strong wind associated with the bow echo, I guess no one checked or reported damage.

    Posted July 28th at 11:29 PM

  46. Becky (West Leyden):

    Anyone care to make a guess on Low temps for Saturday morning. With the air being cool and dry; for me at least, it seems temperatures in the mid 40’s on the Tug and Mid to high 30’s in the Adirondacks seems a good bet.

    Looks like we could stay dry until Sunday through Monday morning. a few showers can’t be ruled out Friday and Saturday. However, with the dry air overhead, I don’t think they will amount to much.

    Posted July 29th at 2:38 PM

  47. fairfield:

    i’ll go for 48 for a low Becky

    Posted July 29th at 4:02 PM

  48. Adam Musyt:

    40’s are a fair bet for early Saturday for much of CNY. The air mass looks sufficiently dry. Adirondacks could possible briefly slip below 40 degrees.


    The cooldown will be a welcome change after a hot and humid July. Incidentally much of the northern hemisphere has been experiencing above average temperatures.


    Today in Moscow, Russian Federation, the high temperature climbed to 100 degrees (37.8 C) – apparantly marking the hottest temperature ever recorded in the past 130 years.  The average high for July 29th in Moscow is 68.

    Posted July 29th at 5:17 PM

  49. Becky (West Leyden):

    A 100 degrees in Moscow, that’s astonishing.

    Posted July 29th at 6:27 PM

  50. Jill Reale (Utica):

    Record low for July 31st is 45 degrees. We are forecasting 47 degrees for tonight into tomorrow morning.

    Posted July 30th at 4:50 AM

  51. Jill Reale (Utica):

    A few lake effect rain showers this morning! That just justifies how cool the airmass is over the Great Lakes.

    Posted July 30th at 6:37 AM

  52. Becky (West Leyden):

    Jill, I’m surprised we saw anything hit the ground this morning; I really thought the air mass aloft was a little too dry.

    Enjoy the cool / dry weather while you can. Because, the humidly returns in a few days along with some wet weather, We will see rain Sunday and Part of Monday. Right now, it looks like scattered showers Monday night and Tuesday. Then we have a cold front moving through Wednesday.

    Posted July 30th at 11:21 AM

  53. Rob (Whitesboro):

    Low here was 46 this morning. Got down to 36 @ Saranac Lake.

    Posted July 31st at 7:42 AM

  54. MG(Point Rock):

    I got down to 42, the chilliest since I had the same temp on July 1st and 3rd. Feels good, but it won’t ripen the tomatoes.

    Posted July 31st at 8:55 AM

  55. Jill Reale (Utica):

    KRME got down to 48 degrees so the record remains as 45 degrees. With overnight lows this cool, we probably won’t crack the top ten warmest Julys. Regardless, get out and enjoy this beautiful day.

    Posted July 31st at 9:20 AM

  56. Becky (West Leyden):

    Low here was 41, currently it is 63

    Posted July 31st at 11:22 AM

  57. Jeff H (Sherburne Hills):

    Again probably one of the coldest in the area last night with the low bottoming out right at 39.0 degrees for about 20 minutes around 6am. It was quite chilly last night at 11 on my way home from work on the bike!

    Posted July 31st at 3:34 PM

  58. Sara:

    Jill, are the storms expected to be strong tomorrow?

    Posted July 31st at 7:04 PM

  59. fairfield:

    low of 45 here this am

    Posted July 31st at 7:34 PM

  60. Jill Reale (Utica):

    Sara,

    Any storms that develop this afternoon will not be on the strong side.

    Posted August 1st at 7:47 AM

  61. Rob (Whitesboro):

    Looks like we could have TD4 by the end of the day. This might be making a run at the U.S. as a hurricane by this time next week.

    Posted August 1st at 8:26 AM

  62. Rob (Whitesboro):

    Doesn’t look like there will be any sustained cool weather anytime soon. I just looked at the CPC outlooks and they have us for above average temputures on all their outlooks. Hopefully we can get L.Ontario up to 100 degrees by the end of fall :O

    Posted August 1st at 10:19 AM

  63. Becky (West Leyden):

    Yeah, the ECMWF long range shows above average temp’s for the Northeast for the next three weeks at least.

    Posted August 1st at 12:11 PM

  64. the man:

    pouring in Sauquoit for the past 10 minutes

    Posted August 1st at 4:28 PM

  65. Jill Reale (Utica):

    Showers and storms are popping up to the south of the Thruway this evening. Some of these cells are slow movers so be careful of puddling on roadways. Trend is warmer but we will see a slight cool down on Satuday.

    Posted August 1st at 5:19 PM

  66. Becky (West Leyden):

    The skinny cape and slow storm speed could mean heavy downpours is spots. for the southern tier and most of central NY the rain should settle down Later tonight. when the sun goes down. However, up north there could be a few showers during the overnight.

    Posted August 1st at 6:38 PM

  67. Jill Reale (Utica):

    new entry up

    Posted August 1st at 9:20 PM

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