Marine Weather and Tides
12/16/2019 NOAA is having trouble with requests that include wind gusts. I am posting graphs without wind gusts until it gets fixed.
10/9/2019 Updated the Marine Zones.
9/4/2019 Fixed the weather maps due to NOAA moving them.
7/25/2019 New feature in the Airports section gives a link to 5 minute updates for data reports.
|Sunrise 5:33AM||Sunset 8:19PM||Tuesday May 26, 2020 10:27 AM MDT (16:27 UTC)||Moonrise 8:48AM||Moonset 12:00AM||Illumination 20%|
7 Day Forecast for Marine Location Near Lochbuie, COHourly EDIT Help
Area Discussion for - Denver/Boulder, CO  (on/off)  Help NOTE: mouseover dotted underlined text for definition
FXUS65 KBOU 261508 AFDBOU
Area Forecast Discussion National Weather Service Denver/Boulder CO 908 AM MDT Tue May 26 2020
UPDATE. Issued at 903 AM MDT Tue May 26 2020
Only minor adjustments to the grids. No updates needed at this time.
SHORT TERM. (Today and tonight) Issued at 312 AM MDT Tue May 26 2020
WNW flow aloft will be over the area today as some mid and high level moisture move across this aftn. Only some clouds will accompany this moisture. Highs will be warmer as readings reach the mid 70s to lower 80s over nern CO.
For tonight, a weak disturbance embedded in the flow aloft will move across overnight. There could be a a few high based showers, over the nrn mtns, late tonight with this feature.
LONG TERM. (Wednesday through Monday) Issued at 312 AM MDT Tue May 26 2020
On Wednesday the deep cutoff low slowly moves across the Arklatex region while the blast furnace ridge builds across CA/AZ. That leaves us in between the two with northwest flow aloft. A decent short wave trough moves across the northern Rockies into the high plains late Wednesday into early Thursday. The GFS and NAM are very aggressive with moisture availability associated with the short wave trough. PW values go to 1.0-1.2" across the plains by midnight Thursday. EC isn't too far behind with 0.80-1.0", which is over 2 standard deviations above normal for that date. QG lift from the trough is weak, but there is a 65 kt jet out of the northwest that places NE colorado in the left exit region, favorable for lift. Some convective instability is available Thursday afternoon via diurnal heating, and continues into early Thursday morning and as the cold pool aloft moves across northern Colorado. Am not buying the significant rain scenario seen on the GFS for late Wednesday into early Thursday yet given all forcing is weak and we believe the moisture content is a bit overdone. Nevertheless, thunderstorm chances are in place from Wednesday afternoon first over the high country, then spreading east and continuing past midnight Thursday given the presence of the trough. Instability and shear are both limited, so not expecting any strong to severe thunderstorms at this time. The warming trend continues Wednesday with low 80s across the plains. 700 mb temps warm to +10 degC by Wednesday afternoon and will support temps in the mid to upper 60s in the mountain valleys and close to 50 at treeline.
On Thursday the blast furnace ridge over the desert southwest shifts slightly east, a tad closer to Colorado. This will usher in drier air, and only isolated thunderstorms are possible across the high country given the limited moisture, and then moving east across the plains. A surface cold front moves across the plains early Thursday with northeast flow near the surface, which will hold dewpoints in the upper 40s so it's not out of the question for a sprinkle or two across the northeast plains Thursday afternoon. There is a good shot of cold advection on the backside of the trough, resulting in 700 mb temps around +5 degC. Thus, highs across the plains will remain in the low to mid 70s, with low to mid 60s in the foothills and mountain valleys.
On Friday an impressive late season extratropical cyclone approaches the Central California coast, which will act to strengthen the downstream ridge and push it further east. By Friday afternoon the ridge axis is across the Four Corners. Flow aloft will be weak out of the northwest. There is enough mid-level moisture for scattered thunderstorms in the afternoon. Across the plains, strong southeast return flow advects dewpoints around 50 deg into our area. Instability will thus respond accordingly with SBCAPE 500-1000 J/kg along the I-25 corridor. Wind shear is weak, likely limiting severe potential but nevertheless thunderstorms are possible, with the best chances across Park County and the Palmer Divide. With the ridge axis in our state, temperatures will warm back into the low to mid 80s across the plains, and 70s in the mountain valleys and foothills.
Saturday through Monday the ridge axis moves over Colorado during the weekend and into the Central plains by Monday. There continues to be moisture advection across the top of the ridge, especially Saturday and Sunday and Monday when subtropical moisture works it's way north out of old Mexico on the backside of the ridge. Ensemble based PW values Sunday and Monday look to be 2 standard deviations above normal for this time of year, as each afternoon values are forecast to be 1-1.25". Thus, afternoon thunderstorms will continue to be in the forecast, especially for the high country (Park County especially), and those storms will move off the mountains each afternoon. On Saturday and Sunday they stand a better chance of surviving east of the mountains with good southeast return flow and mid 50s dewpoints possible. Overall not buying the far above normal PW values because it's unusual this time of year in the middle of a ridge. Wind shear is weak Saturday through Monday with the ridge close by so do not expect severe thunderstorms during this period, but if that much moisture makes it's way into Colorado we'd have to watch out for isolated heavy rain producing storms. At this time we have low confidence in that scenario playing out. Much more confidence in hot temperatures this weekend into early next week, with upper 80s to low 90s expected across the plains.
AVIATION. (For the 18Z TAFS through 18Z Wednesday afternoon) Issued at 903 AM MDT Tue May 26 2020
VFR with no significant impacts expected. West/northwest winds this morning will become more northerly after 18z. By early evening, winds will become more east/southeast and then transition to drainage by 06z.
BOU WATCHES/WARNINGS/ADVISORIES. None.
UPDATE . Cooper SHORT TERM . RPK LONG TERM . Schlatter AVIATION . Cooper
Weather Reporting StationsEDIT (on/off)  Help NOTE: Click on distance to see the station location on a map
Airport ReportsEDIT (on/off)  Help Click EDIT to display multiple airports. Follow links for more data.
|Denver, Denver International Airport, CO||7 mi||34 min||W 5||10.00 mi||A Few Clouds||63°F||39°F||43%||1013.2 hPa|
|Buckley Air Force Base Airport, CO||15 mi||89 min||W 7||10.00 mi||A Few Clouds||59°F||34°F||40%||1014.7 hPa|
|Erie Municipal Airport, CO||19 mi||33 min||NW 3||10.00 mi||Partly Cloudy||62°F||38°F||42%||1020 hPa|
|Broomfield / Jeffco, CO||22 mi||42 min||N 0||10.00 mi||Partly Cloudy||63°F||33°F||34%||1019 hPa|
Link to 5 minute data for KDEN
Wind History from DEN (wind in knots)
|1 day ago||N||NE|
|2 days ago||NE||NE||NE||SE|
EDIT Weekend mode (on/off) (on/off)  Help
EDIT (on/off)  Help
Weather Map(on/off)  Help Weather Map
GEOS Local Image of 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 (12,3,4,5)(on/off)  Help
Ad by Google
I do not sell or share any user data or anything else for that matter. The only personal information I save is in the site log which has a line for each page view which includes the IP address your browser sends in the header as well as which page you requested. I use this to block hackers and other bad actors. I do not use this raw data to create profiles on users. I periodically delete the log files. If you are subject to CCPA, Google ads on this site will not be based on your past behavior so you will likely not see an ad for a lawn mower just because you looked for one at a big box website. I do not believe this site is subject to CCPA but I am doing what I can to follow the guidelines anyway.
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 numerous 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.