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Wettest Month Map

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#1
happ

Posted 07 April 2017 - 07:02 PM

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Wettest month of the year

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#2
Phil

Posted 07 April 2017 - 07:53 PM

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Looks about right. Crap-tons of water around here in J/J/A.
Personal Weather Station, Live Stream on Wunderground: https://www.wundergr...BETHE62#history

Warm season 2017
Thunderstorm days: 10
Severe days: 5
Rain total: 11.58"
Highs at/above 90*F: 16
Warmest high: 99.4*F
Warmest low: 79.7*F

#3
epiceast

Posted 07 April 2017 - 08:02 PM

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What a mess this map is.



#4
happ

Posted 07 April 2017 - 08:42 PM

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What a mess this map is.

 

OK, care to elaborate?



#5
Jesse

Posted 08 April 2017 - 06:19 AM

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What a mess this map is.


It reminds me of your syntax.
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#6
epiceast

Posted 08 April 2017 - 08:20 AM

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OK, care to elaborate?

Just too much going on in here, it overwhelms you with information, because there are 12 months in a year and some spots have like 6 different ones being wettest in 50 mile vicinity...



#7
Phil

Posted 08 April 2017 - 11:02 AM

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Just too much going on in here, it overwhelms you with information, because there are 12 months in a year and some spots have like 6 different ones being wettest in 50 mile vicinity...


Just mentally factor out the noise. It's easy to interpolate climate patterns from the map.

-SW Monsoon peaks late summer/early fall.

-Immediate east coast rainfall peaks with Atlantic SSTs, New England nor'easters deliver most precip in transitional seasons.

-NPAC jet is most-consolidated in late fall/early winter, then slides south/varies later in winter as mid-latitude waters cool and the thermal gradient relaxes.

-Great Lakes' thermal inertia delays peak in temps/rainfall in the downstream vicinity.

-The Gulf of Mexico/Continental temperature gradient is an important governor of interior SE US rainfall.

-Much of US sees its most intense convective rainfall around the summer solstice, when sun angles are highest.

-More moisture available to upper intermountain west in Spring, with residual late-winter jet dynamics and some warm season moisture transport.
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Personal Weather Station, Live Stream on Wunderground: https://www.wundergr...BETHE62#history

Warm season 2017
Thunderstorm days: 10
Severe days: 5
Rain total: 11.58"
Highs at/above 90*F: 16
Warmest high: 99.4*F
Warmest low: 79.7*F

#8
happ

Posted 08 April 2017 - 11:09 AM

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Just mentally factor out the noise. It's easy to interpolate climate patterns from the map.

-SW Monsoon peaks late summer/early fall

-Immediate east coast rainfall peaks with Atlantic SSTs

-NPAC jet is most-consolidated in late fall/early winter, then slides south/varies later in winter as mid-latitude waters cool and the thermal gradient relaxes.

-Great Lakes' thermal inertia delays peak in temps/rainfall in the downstream vicinity.

-The Gulf of Mexico/Continental temperature gradient is an important governor of interior SE US rainfall.

 

I enjoy these types of maps [actually maps in general turn me on]


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#9
happ

Posted 08 April 2017 - 11:14 AM

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Can anyone explain the blue zones that poke into middle Arizona?  Looks like around Phoenix.



#10
epiceast

Posted 08 April 2017 - 12:06 PM

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Just mentally factor out the noise. It's easy to interpolate climate patterns from the map.

-SW Monsoon peaks late summer/early fall.

-Immediate east coast rainfall peaks with Atlantic SSTs, New England nor'easters deliver most precip in transitional seasons.

-NPAC jet is most-consolidated in late fall/early winter, then slides south/varies later in winter as mid-latitude waters cool and the thermal gradient relaxes.

-Great Lakes' thermal inertia delays peak in temps/rainfall in the downstream vicinity.

-The Gulf of Mexico/Continental temperature gradient is an important governor of interior SE US rainfall.

-Much of US sees it's most intense convective rainfall around the summer solstice, when sun angles are highest.

-More moisture available to upper intermountain west in Spring, with residual late-winter jet dynamics and some warm season moisture transport.

Yea that's what I thought when I saw the map. TX/LA border I still don't understand, so many different factors at play there seems just like random noise.



#11
happ

Posted 08 April 2017 - 12:23 PM

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Yea that's what I thought when I saw the map. TX/LA border I still don't understand, so many different factors at play there seems just like random noise.

Some of it has to be random diversity. I am surprised by winter rainfall in the mid-South/ Appalachians



#12
Phil

Posted 08 April 2017 - 02:38 PM

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I enjoy these types of maps [actually maps in general turn me on]


Then you'll like these:

Average annual precipitation, 1981-2010:

837E76C2-4D7B-4311-BA40-EB8B09E8F8DC_zps

JJA average temperature:

6E0A11F5-E4D5-4F16-A136-B214DF0E8FBC_zps

DJF average temperature:

D1666D61-EC7E-422A-933A-FDE1F148D20D_zps
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Personal Weather Station, Live Stream on Wunderground: https://www.wundergr...BETHE62#history

Warm season 2017
Thunderstorm days: 10
Severe days: 5
Rain total: 11.58"
Highs at/above 90*F: 16
Warmest high: 99.4*F
Warmest low: 79.7*F

#13
Phil

Posted 08 April 2017 - 02:53 PM

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Average seasonal snowfall:

snowfall_map.png

Climate types:

88A9FB35-C3B2-4C48-AB29-654CE20FD96D_zps

"Dreariness index" ( :lol: )

5940593F-DDCB-49A9-A246-4204A5BD619B_zps


Date of earliest seasonal snowfall:

080C9B3A-9A0E-4D29-AC48-32AABF6300E5_zps
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Personal Weather Station, Live Stream on Wunderground: https://www.wundergr...BETHE62#history

Warm season 2017
Thunderstorm days: 10
Severe days: 5
Rain total: 11.58"
Highs at/above 90*F: 16
Warmest high: 99.4*F
Warmest low: 79.7*F

#14
epiceast

Posted 08 April 2017 - 03:08 PM

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Average seasonal snowfall:


Climate types:


"Dreariness index" ( :lol: )



Date of earliest seasonal snowfall:
 

 

My personal favorite:

westom.gif

 

I think of it as a map answering this question: Can you go out & tour this mountain range and ski in February(green=yes east of cascades).


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#15
Phil

Posted 08 April 2017 - 03:12 PM

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These are interesting too:

Date of winter "midpoint":

AD06CB16-897D-4E87-B02E-066DC8FF799C_zps

Difference between highest heat index and coldest wind chill:

2BEB255B-8611-4043-9C5A-A7679885073D_zps

Population-adjusted severe weather days per year:

420D1BB7-03E1-4CEE-AE09-75ACAD504F5A_zps

Tornadoes since 1950:

964ACC34-8E01-4B3E-B753-D3020D89034C_zps

Number of warm season derechos from 1996-2013:

73B013CF-1FD1-4A38-8B4C-40BA4438707D_zps
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Personal Weather Station, Live Stream on Wunderground: https://www.wundergr...BETHE62#history

Warm season 2017
Thunderstorm days: 10
Severe days: 5
Rain total: 11.58"
Highs at/above 90*F: 16
Warmest high: 99.4*F
Warmest low: 79.7*F

#16
Scott

Posted 09 April 2017 - 09:52 PM

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12 months in a year and some spots have like 6 different ones being wettest in 50 mile vicinity...

 

 

It is probably accurate, or at least close.  When I lived in Utah, I compiled data for all the weather stations there.  I was able to find different stations in that one state that had all 12 months represented by the wettest months and all twelve months represented for the driest months, depending on the location.

 

Also interesting is that the 30 year averages weren't consistent from one place to the next.   At Park City, for example, the most recent 30 year period when I lived there had September as the wettest month.  For the previous 30 year period September was the driest month!

 

Where I live now, September has been the wettest month for the past 30 years, but it's the driest month in much of Colorado.   

 

Historically December has been our driest month (not in recent years though), but at Steamboat Springs, 40 miles east of here, it has historically been the 1st or 2nd wettest month (January and December are close enough that which one averages wetter toggles between the two depending on the period).


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#17
IbrChris

Posted 12 April 2017 - 06:19 AM

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You'll notice in a lot of the "noisy" areas there's not really a clear "wettest" month because the 2 or more wettest are very close to each other. Thus in City A March might be wettest based on its period of record but in City B a few miles away April might be wettest. Or February. But if we look at the cities we might see a Feb-April breakdown like this: City A: 3.1, 3.2, 3.1. City B: 3.2, 3.1, 3.1. In areas that get a lot of hit and miss "airmass" convection like the SE the averages especially if over a shorter time period might be skewed more by individual events than representative of actual climatic normals.


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The Pacific Northwest: Where storms go to die.


#18
IbrChris

Posted 12 April 2017 - 06:21 AM

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It would be better to examine mean daily precip data and determine the wettest Julian day based on a 30-day rolling average...then plot on a map based on what month that day falls in. You would lose a lot of the "noise".


The Pacific Northwest: Where storms go to die.


#19
Scott

Posted 13 April 2017 - 06:24 AM

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You'll notice in a lot of the "noisy" areas there's not really a clear "wettest" month because the 2 or more wettest are very close to each other. 

 

It would be better to examine mean daily precip data and determine the wettest Julian day based on a 30-day rolling average...then plot on a map based on what month that day falls in. You would lose a lot of the "noise".

 

 

This is true, but in some regions (Utah seems to be the king in this regard, but also Colorado, Nevada, and possibly the Great Lakes) there is a lot of variety in precipitation patters and to which months are wettest and driest, even in regions that aren't that far apart.

 

For example, Salt Lake City and Price aren't really that far apart, but even the rolling averages would be almost a mirror image of each other.   Here are the daily average, but a rolling average would also be an almost mirror image:

 

997252.JPG

 

997253.JPG

 

 

The wettest month in Salt Lake City is April.   April is the driest month in Price.   The wet seasons are also reverse, with mid to late summer being one of the driest time periods in Salt Lake and one of the wettest in Price.   The only real exception to the mirror image is late June and early July, when both locations tend to be dry.

 

Topography and weather patters have a big effect.  Salt Lake gets much of it's moisture from the Pacific Northwest, but Price is shielded from such moisture by the Wasatch Mountains and Wasatch Plateau.    While Salt Lake City tends to have summer as its driest season, Price gets monsoon moisture from the south and southwest.  

 


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#20
happ

Posted 13 April 2017 - 10:34 AM

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Great discussion. Monsoon moisture maybe few and far between in California but can produce the highest 24-hour totals.



#21
IbrChris

Posted 13 April 2017 - 10:35 AM

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This is true, but in some regions (Utah seems to be the king in this regard, but also Colorado, Nevada, and possibly the Great Lakes) there is a lot of variety in precipitation patters and to which months are wettest and driest, even in regions that aren't that far apart.

 

For example, Salt Lake City and Price aren't really that far apart, but even the rolling averages would be almost a mirror image of each other.   Here are the daily average, but a rolling average would also be an almost mirror image:

 

997252.JPG

 

997253.JPG

 

 

The wettest month in Salt Lake City is April.   April is the driest month in Price.   The wet seasons are also reverse, with mid to late summer being one of the driest time periods in Salt Lake and one of the wettest in Price.   The only real exception to the mirror image is late June and early July, when both locations tend to be dry.

 

Topography and weather patters have a big effect.  Salt Lake gets much of it's moisture from the Pacific Northwest, but Price is shielded from such moisture by the Wasatch Mountains and Wasatch Plateau.    While Salt Lake City tends to have summer as its driest season, Price gets monsoon moisture from the south and southwest.  

 

True...and the reason Price doesn't get in on spring precip as much is that even being 120 miles SE of Salt Lake City it is farther removed from a retreating jet (SLC's spring precip is mostly due to west-coast centric upper level troughs and impulses that move through that trough into the intermountain west). Price is also shadowed when it comes to W or NW flow. On the other hand Price fares well in with the SW monsoonal convective regime (S-SE flow). SLC on the other hand often has a drier summertime boundary layer as well as being displaced farther from the heart of the SW monsoon.

You can basically draw a line along the spine of the Wasatch from about I-80 southward to I-70. Areas west of that line generally have a spring precip peak and areas east of that line generally have a mid-late summer precip peak. Of course the higher elevations generally see a wintertime peak with orographic enhancement of mid-latitude systems.

South of I-70 you get into more of a summertime peak in the valleys at least both across SW Utah and the Lake Powell/San Juan area (though the lower deserts around St George often see a winter peak for a more bimodal precip pattern).


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The Pacific Northwest: Where storms go to die.


#22
happ

Posted 13 April 2017 - 10:56 AM

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I noticed this winter that atmospheric river events penetrated Utah on occasion.   



#23
IbrChris

Posted 13 April 2017 - 10:57 AM

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I noticed this winter that atmospheric river events penetrated Utah on occasion.   

Yeah generally anything coming into California can deliver precip into Utah fairly easily. Systems tend to undergo cyclolysis in the western Great Basin but can restrengthen over Utah.


The Pacific Northwest: Where storms go to die.


#24
happ

Posted 13 April 2017 - 11:06 AM

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Off-topic a bit but look at the temp anomaly across Midwest/ South

 

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#25
IbrChris

Posted 13 April 2017 - 11:08 AM

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Off-topic a bit but look at the temp anomaly across Midwest/ South

Yep also impressive chill in the PacNW especially interior valleys/basins.


The Pacific Northwest: Where storms go to die.


#26
happ

Posted 13 April 2017 - 11:11 AM

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Yep also impressive chill in the PacNW especially interior valleys/basins.

Are there analogues to compare?



#27
happ

Posted 13 April 2017 - 11:12 AM

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Chicago will hit 80F this weekend.



#28
IbrChris

Posted 13 April 2017 - 11:15 AM

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Are there analogues to compare?

Probably but I haven't delved into it. Vendor forecasts for JJA based in part on analogs for this past winter/early spring along with expected trends in ENSO suggest coastal warmth with cool potential for the Upper Midwest and Great Lakes for JJA.


The Pacific Northwest: Where storms go to die.


#29
happ

Posted 13 April 2017 - 11:17 AM

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Probably but I haven't delved into it. Vendor forecasts for JJA based in part on analogs for this past winter/early spring along with expected trends in ENSO suggest coastal warmth with cool potential for the Upper Midwest and Great Lakes for JJA.

 

Hopefully Utah and California will get in on some generous monsoon moisture.



#30
BLI snowman

Posted 13 April 2017 - 11:53 AM

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Can anyone explain the blue zones that poke into middle Arizona?  Looks like around Phoenix.

 

The summer monsoonal pushes are often high-based in nature and thus miss producing much precip in the lower valleys of western AZ (and central AZ in the case of Phoenix). Like Southern California, those valleys are still more reliant on the formation of a subtropical jet in the mid to late winter.


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#31
happ

Posted 14 April 2017 - 12:41 PM

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Isn't this the truth? :(

Attached Files



#32
Phil

Posted 14 April 2017 - 04:28 PM

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Isn't this the truth? :(


DC bullseye! Likely a result of the hot, swampy air that emanates from the WH on a regular basis.
Personal Weather Station, Live Stream on Wunderground: https://www.wundergr...BETHE62#history

Warm season 2017
Thunderstorm days: 10
Severe days: 5
Rain total: 11.58"
Highs at/above 90*F: 16
Warmest high: 99.4*F
Warmest low: 79.7*F