Wednesday, August21, 2019

Marine Weather and Tides
Sheridan, CO

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7/25/2019 New feature in the Airports section gives a link to 5 minute updates for data reports.
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Sunrise 6:15AMSunset 7:51PM Tuesday August 20, 2019 10:35 PM MDT (04:35 UTC) Moonrise 9:41PMMoonset 9:57AM Illumination 70% Phase: Waning Gibbous; Moon at 20 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 Sheridan, CO
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location: 39.68, -105.06     debug

Area Discussion for - Denver/Boulder, CO
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Fxus65 kbou 210323
area forecast discussion
national weather service denver boulder co
923 pm mdt Tue aug 20 2019

Issued at 839 pm mdt Tue aug 20 2019
minor updates were made to pops to reflect the current convection.

Right now, it appears the majority of the storms will be sub-
severe this evening. However, better instability exists over the
i-76 corridor northeast of dia up to the cheyenne ridge as the
rap mesoanalysis has over 2000 j kg of mixed layer CAPE with up
to 3000 j kg near the nebraska border. This is enough to support
the potential for a severe storm or two with large hail the
primary threat. The severe thunderstorm watch GOES until 11pm for
weld and morgan counties which should be sufficient to encompass
the threat.

Storms may continue into the early morning hours across the far
northeast corner. Stratus and fog may develop but there is low
confidence on the fog.

Short term (this evening through Wednesday)
issued at 220 pm mdt Tue aug 20 2019
fair weather CU over the higher terrain and east-west ridges this
afternoon will eventually give way to convection by this late
afternoon. By 21z, will expect to see some isolated gusty
convection fire off the mountains, foothills and ridges and expect
these to migrate off onto the east plains while strengthening
into the evening hours as they move into much better moisture.

Latest nam12 run has mlcapes out on the far northeast plains in
the 3000-3800 j kg range on the southern slope of a theta-e ridge
extending from southeast wyoming eastward into western and
southern nebraska. Rich surface boundary layer moisture of 8-10
g kg will reside over the far NE plains lending to the potential
for strong to severe storms this evening along with the potential
for heavy rain and large hail. Storm motion for this evening is on
the weak side as 500-300mb layer winds are only in the 15 to 25kt
range. A few of the stronger, slower or back-built storms could
present some local hydro issues later this evening out along the
i-76 corridor mainly northeast of denver. Behind tonight's batch
of convection will be the passage of much cooler air behind an
approaching cold front currently near the sheridan wy black
hills sd vicinity as a decent 1022mb surface high spreads
southward across north plains states tonight. Will look for the
main wind shift arrival in the 05-07z Wednesday timeframe. This
will likely keep a north to northeasterly component to the surface
winds overnight and into Wednesday morning along with areas of
low clouds towards dawn.

For Wednesday, with the initial cool moist, stable air, will look
for light easterlies through the morning along with the potential
for low clouds and patchy fog over the far eastern plains. Highs
along the urban corridor and plains should only reach into the
lower to mid 80s. Forecast soundings indicate the profile
remaining fairly stable in the lower levels through late
afternoon, so with persistent easterlies through the day, the
best mlcapes and boundary layer specific humidities will build up
against the urban front range and foothills. Will keep the
scattered pops across the area, and at this time will expect the
main impact to be heavy rain associated with the storms along with
potential local hydro issues. Storm motion from 500-300mb winds
aloft is still fairly weak and with surface easterlies and
disorganized flow in the low to mid-levels, a few storms may have
difficulty exiting locations which may be a problem for flood
prone area such as an urban areas and burn scars.

With cooler temperatures along with higher daytime dew points and
relative humidity, the fire danger should relax for Wednesday.

Long term (Wednesday night through Tuesday)
issued at 220 pm mdt Tue aug 20 2019
scattered thunderstorms will continue into the evening hours
along the front range and across the northeast plains Wednesday. A
few severe storms with large hail will be possible due cape
climbing to 1500-2500 j kg and 0-6km bulk shear climbing to 30-40

A weak westerly flow aloft will again be over the state Thursday.

Surface low pressure over central colorado and wyoming will
produce southeast winds across eastern colorado Thursday. This
will help keep moisture over the much of the area. Isolated to
scattered storms should form over the front range and eastern
plains Thursday afternoon and evening. Temperatures warm a little
over Wednesday's highs with readings in the mid to upper 80s.

On Friday, moisture is starting to get pushed to the east by the
westerly flow aloft. May have enough moisture for a few storms.

The best chance will be across the eastern plains. With the
drying, expect temperatures to warm back around 90 degrees.

For the weekend and early next week, the upper level ridge will
shift south as westerly flow aloft increase. This will dry out the
airmass and warm it up. Dry conditions with highs in the 90s is
expected for the weekend. A weak cold front may back into the area
Sunday night and early Monday. This will bring cooler air with
highs expected to reach the upper 80s for Monday and Tuesday.

Could see enough moisture return to the area for storms on

Aviation (for the 00z tafs through 00z Wednesday evening)
issued at 839 pm mdt Tue aug 20 2019
a thunderstorm or two may briefly pass over the terminals this
evening with minor, if any, impacts. Outflow boundaries may continue
to develop and push through the terminals tonight shifting winds
temporarily. The next concern shifts to the possible development
of stratus during the early morning hours. With plenty of low
level moisture in place, it is better than a 50 percent chance
that stratus develops so I included a from group for it at den.

There is some uncertainty, though, as most models have downslope
winds for much of the night so it is not a sure bet.

Strong thunderstorms will be possible Wednesday afternoon with
gusty winds and lower ceilings the primary threats.

Bou watches warnings advisories

Update... Danielson
short term... Fredin
long term... Meier
aviation... Danielson

Weather Reporting Stations
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Airport Reports
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AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
Denver - Centennial Airport, CO14 mi42 minW 610.00 miMostly Cloudy73°F57°F57%1015 hPa
Broomfield / Jeffco, CO16 mi50 minNW 310.00 miMostly Cloudy77°F51°F42%1023.7 hPa
Buckley Air Force Base Airport, CO17 mi97 minSE 1710.00 miThunderstorm Light Rain71°F56°F61%1014.6 hPa
Erie Municipal Airport, CO23 mi41 minSSE 310.00 mi72°F50°F47%1023.7 hPa
Denver, Denver International Airport, CO24 mi42 minENE 610.00 miThunderstorm in Vicinity74°F52°F46%1013.1 hPa

Link to 5 minute data for KAPA

Wind History from APA (wind in knots)
Last 24hr------S33SW4S3SW7CalmSE5W3CalmN8NE12
1 day agoS9--S7----SW6SE3CalmCalmW7--W3W3Calm4--53
2 days agoSE6S8SW7--SW7SE4CalmSW8----N53N4NE5N7N7

Tide / Current Tables for
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Weather Map and Satellite Images
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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.
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Wind Forecast for Denver/Boulder, CO (0,6,7,8)
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Ground Weather Radar Station Denver/Boulder, CO
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