Marine Weather and Tides
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.
6/2/2019. Many thanks to a user for reporting an error on one of the Edit pages. The switch to PHP 7.2 caused many pages that previously worked to quit working. I fixed many but I still depend on users to report ones I missed. Please report errors HERE or send an email to me at L-36.com. Allen
|Sunrise 7:07AM||Sunset 4:34PM||Friday December 6, 2019 1:33 PM MST (20:33 UTC)||Moonrise 2:52PM||Moonset 2:22AM||Illumination 74%|
7 Day Forecast for Marine Location Near Nunn, COHourly EDIT Help
Area Discussion for - Denver/Boulder, CO  (on/off)  Help NOTE: mouseover dotted underlined text for definition
FXUS65 KBOU 061732 AFDBOU
Area Forecast Discussion National Weather Service Denver/Boulder CO 1032 AM MST Fri Dec 6 2019
UPDATE. Issued at 1032 AM MST Fri Dec 6 2019
Other than making some adjustments for the persistent fog around Greeley and Sterling, no other changes to the forecast package are needed. Cold air seems to be strongly entrenched in parts of the South Platte River Valley with dense fog the result. The fog should dissipate during the afternoon. Temperatures will be cooler in the areas that have fog the longest. An area of stratus over Grand and Jackson County also seems to be dissipating according to satellite imagery. Weather across the rest of the forecast area will be mostly sunny through the afternoon.
UPDATE Issued at 320 AM MST Fri Dec 6 2019
Areas of fog have thickened quickly over the northern and northeastern plains, and won't likely improve until mid morning, will issue a Dense Fog Advisory.
SHORT TERM. (Today and tonight) Issued at 240 AM MST Fri Dec 6 2019
The state has been left under northwesterly flow aloft as yesterday's weather system has moved into the Great Plains, and an upper ridge builds over the western US. Moisture in the northwest flow has kept the high country stuck under cloud cover with a few flurries possible. High surface pressure over the Great Plains has pushed stratus and areas of fog into the state's northeastern corner, while clearing skies early this morning have allowed for patchy fog to form further west in the South Platte River valley and closer to the urban corridor. 500 mb heights will increase through the day as the ridge axis is expected over the forecast area late tonight. Therefore expecting a subsident airmass today with little mixing. What fog continues to form early this morning will likely last quite a while, especially in the stable South Platte River Valley. Some models, notable the NAM Nest keeps dense fog in all day, however, it wanted near zero visibility by last evening, and that didn't happen. Will keep fog in the forecast through the morning hours, dissipating after noon. This may need to be extended into the early afternoon. Max temperatures may be quite varied, depending on where its more stable and possibly fog covered all day, with highs in the mid 30s there, and mid 40s elsewhere. I did lower max readings in the South Platte River valley in anticipation of the later fog dissipation. In the high country, clouds will likely stick around in the northwesterly flow, so similar readings to yesterday will be expected.
Tonight, a surface trough begins to deepen along the lee of the Rockies to induce some downsloping warmer winds in and near the foothills. Elsewhere, out on the plains, areas of fog will likely form again under light winds and recent precipitation.
LONG TERM. (Saturday through Thursday) Issued at 240 AM MST Fri Dec 6 2019
The weekend will start off on a warm note under an upper level ridge and strong warm advection. With 700 mb temperatures warming to around +5C, healthy lee troughing, and a dwindling snowpack on the plains, we'll respond nicely to sunshine on Saturday. There may be some morning fog in the Platte River Valley northeast of Denver, and the greater snowpack/shallow inversions there will likely limit the warmup. Outside of that, however, we'll see much above normal temperatures with upper 50s to mid 60s across Denver and the Palmer Divide. The warmest readings should be over the southern sections of town into Douglas and Elbert Counties where inversions will be very shallow and quick to burn off. Even locations like Boulder could pop above 60F if we get some westerly winds off the foothills late in the day. Breezy/windy conditions will persist across the mountains and foothills with the lee trough and 30-40 knot cross mountain flow.
On Sunday, the deeper upper level storm system driving into northern and Central California will undergo some shearing as another trough drops southeast across the northern Rockies. There will be some upper level support as seen in the QG fields, and fair orographics with westerly flow and increasing mid level moisture ahead of the trough. Moisture does not appear as impressive in the latest guidance, with 700-500 mb specific humidity only peaking at 2 g/kg early in the event. We'll still see snow and areas of blowing snow in the mountains and travel impacts, with overall moderate snow accumulations thanks to the duration of this event. The mountain snow should continue into Monday with another shot of cold advection in favorable northwest flow. A cold front will push across the plains, bringing a chance of light snow as well by Sunday night and Monday. After mild, pre-frontal temperatures on Sunday, we'll return to below normal temperatures Monday and Tuesday.
For the latter half of next week, ensemble guidance is still showing a return to normal or slightly above normal temperatures. A weak wave may push through the ridge late Thursday or Friday with a chance of snow at least for the high country.
AVIATION. (For the 18Z TAFS through 18Z Saturday afternoon) Issued at 1032 AM MST Fri Dec 6 2019
Minimal aviation impacts are expected as skies remain mostly clear and winds remain light.
BOU WATCHES/WARNINGS/ADVISORIES. None.
UPDATE . Dankers SHORT TERM . Kriederman LONG TERM . Barjenbruch AVIATION . Dankers
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.
|Fort Collins/Loveland - Northern Colorado Regional Airport, CO||16 mi||38 min||N 0||10.00 mi||Fair||39°F||30°F||70%||1024.4 hPa|
|Greeley, Greeley-Weld County Airport, CO||21 mi||38 min||N 0||0.15 mi||Fog||35°F||30°F||85%||1027.3 hPa|
Link to 5 minute data for KFNL
Wind History from FNL (wind in knots)
|1 day ago||Calm||E||E||NE||Calm||Calm||NE||Calm||N||NE||Calm||Calm||SW||Calm||Calm||N||N||N||N||N||N||NE||NE||N|
|2 days ago||E||N||N||N||NE||Calm||Calm||NE||NW||Calm||Calm||Calm||SW||S||S||Calm||NE||N||S||Calm||Calm||NE |
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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 (15,3,4,5)(on/off)  Help
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