Tuesday, January22, 2019 L-36.com

Marine Weather and Tides
Nunn, CO

Version 3.4
What's New / NOTES
10/6/2018 Colors of tide XTide graphs changed to emphasize that they were upgraded. See next note. Comments welcome.
10/4/2018 I have fixed XTide and updated the harmonic files. There were some name changes so you might have to click EDIT to find the new station name.

Sunrise 7:17AMSunset 5:06PM Monday January 21, 2019 11:28 PM MST (06:28 UTC) Moonrise 6:55PMMoonset 8:45AM Illumination 98% Phase: Waning Gibbous; Moon at 16 days in cycle
NOTE: Some of the data on this page has not been verified and should be used with that in mind. It may and occasionally will, be wrong. The tide reports are by xtide and are NOT FOR NAVIGATION.
Marine Forecasts
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7 Day Forecast for Marine Location Near Nunn, CO
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location: 40.66, -104.88     debug

Area Discussion for - Denver/Boulder, CO
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Fxus65 kbou 220249
area forecast discussion
national weather service denver boulder co
749 pm mst Mon jan 21 2019

Issued at 745 pm mst Mon jan 21 2019
main concern is potential for blizzard conditions on the plains
later this evening and overnight. Storm system timing is
generally on track as main cold front as just moved through
cheyenne with north winds up to 30 knots and snow has just
developed there. This will result in the front sweeping through
the denver area between 9 and 10 pm, and then through much of the
plains by midnight.

Snow will rapidly develop behind the front and looks like the
highest snowfall intensities will be in this period between 10 pm
and 1 am with snowfall rates of 1 to 2 inches of snow per hour
possible. With this heavier burst of snow, snow is wetter so don't
expect a lot of initial blowing snow but certainly could see the
lower visibilities. May have a hard time seeing the blizzard
conditions for the required 3 hours as it may be 1-2 hours at most.

Hi resolution models showing a brief lull in the snowfall after
the initial burst but then redevelops lighter snowfall later
tonight and through early Tuesday morning. With the strong winds
this may result in more reduced visibilities from the combination
of snow and winds with snow and blowing snow poor visibilities.

Regardless, travel will be tricky later tonight through Tuesday
morning. Still looks like heaviest snowfall from denver south and
eastward towards the palmer divide.

For now will not adjust any of the hilites but the 8 pm start time
is a bit early to see blizzard conditions and will likely be
later. Will adjust the upcoming statement to signify this.

Short term (this evening through Tuesday)
issued at 152 pm mst Mon jan 21 2019

Blizzard conditions for parts of northeast colorado tonight
and Tuesday morning...

winter storm and blizzard conditions are still expected for parts
of northeast colorado tonight. Complex set up is making for a
challenging forecast. A long wave trough will shift east across
the intermountain west tonight and Tuesday. Water vapor satellite
imagery showing lift over wyoming. Appears this is associated with
the left exit region of the jet. There is also a circulation over
southeast utah which is expected to move eastward and be the main
focus for snow across eastern colorado. The 12z model runs are
still far apart on where the upper level and surface lows form.

The GFS is on the north and quicker side with the 500mb low
forming over far northeast colorado around 06z. The ECMWF is
farther south with the 500mb low forming near colorado springs and
pueblo. The past few runs of the ECMWF have been consistent. The
12z NAM and also the hrrr and rap runs have trended south towards
the ecwmf. The strongest pressure falls are over southern
colorado. In addition to this, the colder air is farther west and
south than the models are showing. Because of this will go with
the southern track for this storm.

The southern track shows a swath of about a half inch of QPF with
localized areas of more. Liquid to snow ratios start off around
ten to one. Strong colder air advection should rapidly increase
liquid to snow ratios to 20 to one. So the swath of half inch qpf
should result in 5 to 10 inches of snow.

In addition to the snow, strong northerly winds are expected to
form behind the low and create blizzard conditions. Strong cold
air advection will help mix winds aloft down. Expecting gusts to
50 mph across the eastern plains, a few locations could approach
60 mph.

Snow will increase in the mountains this afternoon and continue
overnight ahead of the trough. A strong cold front will drop south
out of wyoming as a surface low deepens over eastern colorado.

Snow will form behind the front this evening and spread southeast
overnight. Northerly winds off the cheyenne ridge is expected to
limit snowfall near the wyoming border. These northerly winds
become upslope south of i-76 and are expected to enhance snowfall.

Thinking this will produce 5 to 10 inches of snow from akron to
the palmer divide. Expect a period of snow for the denver area due
to upslope winds behind the front and lift from the trough.

To summarize, an area of heavy snow (5-10 inches) is expected to
form on the backside of a low that will form over eastern
colorado. Snowfall amounts will greatly depending on where this
low forms. Confidence on where this will occur is low. However 50
mph, along with even a little snow should produce blizzard
conditions. Travel tonight and Tuesday morning is discouraged
across eastern colorado. Check conditions before traveling.

Long term (Tuesday night through Monday)
issued at 152 pm mst Mon jan 21 2019
a ridge of high pressure will be along the west coast Wednesday
through Friday with a strong northwesterly flow aloft over
colorado. The models have been fairly consistent with a couple of
embedded short waves. The first one is expected to drop out of the
northern rockies and into the CWA Wednesday night into Thursday.

This features will likely impact the mountains primarily. The gfs
and nam12 models indicate 24 hr snowfall in the 5-10 inch range.

This coupled with the strong flow aloft may require a highlight
at some point. May also see snow showers develop over the
northeast plains as well, with isolated to scattered coverage.

Temperatures on Wednesday may climb back to near normal with
gusty westerly winds developing ahead of this system, but then a
cold front moves across Wednesday night with highs dropping back
into the lower 30s on Thursday. A replay of this scenario may occur
on Friday night, when another embedded drop out of the northern
rockies and into the high country. Temperatures on Friday are
expected to warm to around normal, then a little cooler on
Saturday following the passage of this next short wave. The
overall pattern remains the same over the weekend with the ridge
over the west coast, and a persistent northwesterly flow aloft
over co. Sunday appears to be dry and warmer at this time. Yet
another system could impact the CWA Sunday night into Monday.

Aviation (for the 00z tafs through 00z Tuesday evening)
issued at 720 pm mst Mon jan 21 2019
initial surge has moved into kden with easterly winds but the main
front will be at local terminals between 04-5z with strong
northerly up to 30kt. Snow will develop rapidly behind the front
with ifr conditions and potential for heavy snowfall rates of 1-2
inches per hour through 07z with visibilities below 1 4 mile.

Could see a lull have the initial snowfall burst after midnight
and and then light snow redevelops again around 10-11z and through
Tuesday morning where there can be some blowing snow with winds
up to 25kt. Snow fall accumulations look to be in the 3-5 inches,
with higher potential up to 7 inches at apa.

Bou watches warnings advisories
Winter weather advisory until 9 am mst Tuesday for coz036-039-

Winter weather advisory until 9 am mst Tuesday for coz031-033-

Blizzard warning until 11 am mst Tuesday for coz041-044>046-049.

Update... Entrekin
short term... Meier
long term... Cooper
aviation... Entrekin

Weather Reporting Stations
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Airport Reports
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AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
Fort Collins/Loveland - Northern Colorado Regional Airport, CO16 mi33 minN 28 G 3310.00 miPartly Cloudy and Windy28°F21°F78%1007 hPa
Greeley, Greeley-Weld County Airport, CO21 mi33 minN 25 G 3310.00 miPartly Cloudy and Windy26°F19°F75%1010.7 hPa

Wind History from FNL (wind in knots)
Last 24hrN7NE7N75NE9--CalmNE4N3CalmE3NE5NE4E6SE4W3S11N14
1 day agoNE4E3NW3NW7N7
2 days agoS3E11SW3S6SW7S4S4S53N4N3E6SE54CalmE6SE5S6CalmN5NE6S6SW5SW5

Tide / Current Tables for
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Tide / Current Tables for
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Weather Map and Satellite Images
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GOES Local Image of CentralPlains    EDIT
NOTE: East coast views moved to GEOS-16. They are experimental and not well supported by NOAA so they may not be correct so be warned. This change required redoing a large amount of the GOES code. If the image you are expecting is not showing, please let me know. You may need to use the EDIT function to update your location.
Link to Loop

Other links: Northern Pacific     Contential US     Full GOES-East
Wind Forecast for Denver/Boulder, CO (1,6,7,8)
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Ground Weather Radar Station Cheyenne, WY
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The information on this web site has not been checked for accuracy. It is for entertainment purposes only and should be independently verified before using for any other reason. There are five sources. 1) Documents and manuals from a variety of sources. These have not been checked for accuracy and in many cases have not even been read by anyone associated with L-36.com. I have no idea of they are useful or accurate, I leave that to the reader. 2) Articles others have written and submitted. If you have questions on these, please contact the author. 3) Articles that represent my personal opinions. These are intended to promote thought and for entertainment. These are not intended to be fact, they are my opinions. 4) Small programs that generate result presented on a web page. Like any computer program, these may and in some cases do have errors. Almost all of these also make simplifying assumptions so they are not totally accurate even if there are no errors. Please verify all results. 5) Weather information is from numerious of sources and is presented automatically. It is not checked for accuracy either by anyone at L-36.com or by the source which is typically the US Government. See the NOAA web site for their disclaimer. Finally, tide and current data on this site is from 2007 and 2008 data bases, which may contain even older data. Changes in harbors due to building or dredging change tides and currents and for that reason many of the locations presented are no longer supported by newer data bases. For example, there is very little tidal current data in newer data bases so current data is likely wrong to some extent. This data is NOT FOR NAVIGATION. See the XTide disclaimer for details. In addition, tide and current are influenced by storms, river flow, and other factors beyond the ability of any predictive program.