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Fall Banter, Observation and General Discussion 2018

CapturedNature

By CapturedNature,
in New England

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CoastalWx

CoastalWx

Posted
Posted
39 minutes ago, dendrite said:

I’ll have to look up the calibration numbers. The little screws under each side of the tipping mechanism would have to be turned counterclockwise (lefty loosey). Getting them slightly higher makes it takes less liquid for the tipper to tip. There’s % numbers on the gauge I believe which indicate 1% or 2%, but I’d need to read up on it to recall if turning each side 2% equals a 2% change or a 4% change. An event today with heavy rates may result in some splash out too. If you tried to calibrate it for today you’d probably be overreporting slightly in normal synoptic events. Do you have a run down on some Davis/Stratus total comparisons so we can come up with an avg % error?

I don’t,  but I need to be more aware of that. I’ll keep an eye on that. 

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HoarfrostHubb

HoarfrostHubb

Posted
Posted

I’m thinking the top number might be off, but would not be surprised if these were true 

Worcester County...
   Baldwinville          6.62   951 AM  9/18  Amateur Radio
   Ashburnham            4.76  1009 AM  9/18  Co-Op Observer
   Fitchburg             4.11  1000 AM  9/18  Co-Op Observer
   Lunenburg             4.02  1112 AM  9/18  Ham Radio
   Ashburnham North      2.78   700 AM  9/18  Co-Op Observer
   Westborough           2.64  1157 AM  9/18  Trained Spotter
   2 NNE Fitchburg       2.49   800 AM  9/18  CoCoRaHS
   Fitchburg Coop        2.49   800 AM  9/18  Co-Op Observer
   4 SE Royalston        2.26   730 AM  9/18  HADS
   1 SSW Gardner         2.16   700 AM  9/18  CoCoRaHS
   Birch Hill Dam        2.13   700 AM  9/18  Co-Op Observer
   Athol                 2.07   815 AM  9/18  Ham Radio
   Tully Lake            1.97   700 AM  9/18  Co-Op Observer
   Royalston             1.81   715 AM  9/18  Ham Radio
   Fitchburg AP          1.26   752 AM  9/18  ASOS
   1 NNE Barre           1.22   700 AM  9/18  CoCoRaHS
   Westminster           1.19   712 AM  9/18  Ham Radio
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dendrite

dendrite

Posted
Posted
1 hour ago, CoastalWx said:

I don’t,  but I need to be more aware of that. I’ll keep an eye on that. 

From the Davis manual...

Quote

The non-metric version of the rain collector is calibrated at the factory so the spoons tip (and records rainfall) for each 0.01" of rain. The metric version is calibrated so the spoons tip for each 0.2 mm. To adjust the calibration slightly, use a 3/16” (or 5 mm) wrench to rotate the adjustment screws which are located underneath the tipping spoons. (See “Rain Collector Internal Components” on page 2.) The adjustment guide embossed in the platform shows how far you must rotate both screws in turn to effect a 1% and a 2% change. Moving the screws in the positive (+) direction causes the spoons to tip more times (i.e. give a larger count) for a given amount of water. Note: Modify both adjustment screws by the same amount. To check the accuracy of the rain collector, compare the Davis rain collector with a tube type rain gauge. Use a rain gauge with an aperture of at least 4 inches. Any smaller and the readings obtained may not be accurate. Place the tube type rain gauge directly next to the Davis rain collector. Compare the totals on three storms to determine whether your rain collector needs calibration and by how much. Adjust the screws to fine-tune the reading for the next three storms if necessary. Note: Avoid comparison to rainfall readings obtained from television, radio, newspapers, or neighbors’ readings. Such readings are not an accurate measurement of the weather conditions in your specific location. The rain collector is carefully tested at the factory to conform to the specifications listed in the back of this manual.

So if you want to have a 1% change you need to change both screws 1%.

I calibrated mine 5-10 years ago and it's still pretty much spot on with the Stratus.

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Lava Rock

Lava Rock

Posted
Posted

How do you calibrate? Mine reads low too

Is this a sudden, recent issue or has it been gradually undermeasuring?
Definitely try to get the bubble centered to rule that out. Make sure the cone hole is clear and there is nothing obstructing the tipping mechanism. If it’s still a fail after that it may be time to adjust the screws and calibrate it.


Sent from my Pixel 2 using Tapatalk

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Dan

Dan

Posted
Posted 

 
7 hours ago, OceanStWx said:

Wouldn't shock me. The meso was decent there.

 

7 hours ago, Damage In Tolland said:

Sounds like a TOR hit Saugus 

  

000
NOUS41 KBOX 182248
PNSBOX
CTZ002>004-MAZ002>024-026-RIZ001>008-192300-

PUBLIC INFORMATION STATEMENT
NATIONAL WEATHER SERVICE BOSTON/NORTON MA
648 PM EDT TUE SEP 18 2018

...NWS DAMAGE SURVEY FOR 9/18/18 WIND DAMAGE IN 
SAUGUS, MASSACHUSETTS...

LOCATION...SAUGUS IN ESSEX COUNTY MA
DATE...SEPTEMBER 18 2018
ESTIMATED TIME...1107 AM EDT
ESTIMATED MAXIMUM WIND SPEED...70-75 MPH
MAXIMUM PATH WIDTH...250 YARDS
PATH LENGTH...1 MILE
BEGINNING LAT/LON...42.4613/-71.0088
ENDING LAT/LON...42.4581/-70.9901
* FATALITIES...0
* INJURIES...0

...SUMMARY...
A NATIONAL WEATHER SERVICE SURVEY TEAM LOOKED FIRST-HAND AT 
DAMAGE THAT OCCURRED LATE THIS MORNING IN SAUGUS, MASSACHUSETTS. 
THEY DETERMINED THAT A MICROBURST, OR STRAIGHT-LINE WINDS, WAS 
THE CAUSE OF DOWNED TREES AND TREE LIMBS, A FEW OF WHICH FELL 
AGAINST HOMES. THE DAMAGE WAS NOT THE RESULT OF A TORNADO.

ALTHOUGH TREES, TREE LIMBS, AND SOME WIRES WERE DOWNED ACROSS 
MANY PARTS OF SAUGUS, THE MOST CONCENTRATED AREA STRETCHED
FROM THE WESTERN PART OF RIVERSIDE CEMETERY EASTWARD TO BETWEEN 
STOCKER PLAYGROUND AND LINCOLN AVENUE. THIS IS APPROXIMATELY
A ONE-MILE LENGTH. THE MAXIMUM WIDTH OF THE MICROBURST WAS
AROUND 250 YARDS. THE ESTIMATED MAXIMUM WIND SPEED WAS
70 TO 75 MPH.

THE SURVEY TEAM WOULD LIKE TO THANK THE FIRE DEPARTMENT,
SKYWARN AMATEUR RADIO OPERATORS, AND LOCAL RESIDENTS FOR 
THEIR HELP.

THE INFORMATION IN THIS STATEMENT IS PRELIMINARY AND SUBJECT 
TO CHANGE PENDING FINAL REVIEW OF THE EVENT AND PUBLICATION 
IN NWS STORM DATA.

$$

BABCOCK/DUNHAM/FIELD

FOR THE LATEST UPDATES, PLEASE VISIT OUR WEBPAGE AT
WWW.WEATHER.GOV/BOSTON

YOU CAN FOLLOW US ON FACEBOOK AT
WWW.FACEBOOK.COM/NWSBOSTON

YOU CAN FOLLOW US ON TWITTER AT
@NWSBOSTON
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Typhoon Tip

Typhoon Tip

Posted
Posted

that feature out there probably has a decent amount of IKE ...  with that much momentum presented by satellite.  Spread out over that large of an area, even though the motion appears mainly lower tropospheric not very deep, should convection migrate inwards it could be interesting.

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