Marine Weather and Tides
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 5:40AM||Sunset 8:09PM||Monday May 20, 2019 2:24 PM MDT (20:24 UTC)||Moonrise 10:08PM||Moonset 7:10AM||Illumination 97%|
7 Day Forecast for Marine Location Near Calhan, COHourly EDIT Help
Area Discussion for - Denver/Boulder, CO  (on/off)  Help NOTE: mouseover dotted underlined text for definition
|Fxus65 kbou 201541|
area forecast discussion
national weather service denver boulder co
941 am mdt Mon may 20 2019
Issued at 941 am mdt Mon may 20 2019
current moist and unstable forecast still on track this morning
as a broad closed upper trough over the southern great basin
provides widespread QG ascent aloft ovr NE co. Fairly high surface
pressure over the north central us plains is proving cold
easterly return surface flow onto eastern co. These current low
level easterlies, with t dpts only in the lower 40s mid 30s will
continue into the afternoon sustaining the low lvl upslope ascent
with stratiform rain and drizzle across the plains. From this
push, the 12z den sounding hinting at a freezing drizzle type
profile this morning which we're seeing on the some of the iced-
over foothills cams and also near the co wy border. Lower
elevations should be warm enough near the surface surface to
remain water. Snow level, currently near 7500 feet east of the
divide, should hover near that level thru the afternoon before
lowering into the evening. Higher mountains west of the divide are
currently seeing patches of blue skies, but will gradully fill in
by the aftn as trof approaches with widespread mountain snow
still expected for the overnight period.
Main issue heading into the afternoon will be the threat for ts
action after 20z. Moist and unstable southwesterly flow aloft will
likely contain an embedded aftn early eveing batch of storms over
cwa from better capes existing over so SE co where SPC has
mrgl slgt threat for storms. Current short term models still
hanging on to a period of high QPF from this potential convective
feature later tonight over the plains. To complicate this, brief
mesoscale subsidence behind batch of storms could bring brief
drying for a time later this evening along palmer and far plains.
Despite a few models indicating significant QPF asociated along
the front range with tstorms, believe we'll be in more of
cool cold stratiform enviroment with strongest storms developing
and sustaining out over the far eastern plains into ks ne, thus
no hydro concerns at this point for this evening along the front
range. At this time still expecting precip in the form of snow
along the front range urban corridor as the entire column cools
under the freezing mark by 09z tue. Will look for the gradually
decereasing snow levels into the late evening with snow down to
near 5000ft by 12z tue.
Short term (today and tonight)
issued at 440 am mdt Mon may 20 2019
as usual, nothing is easy around here due to the influence of the
mtns, which always causes issues with the models.
Water vapor from satellite shows a well defined mid level
circulation back near SW utah which will move to the four corners
area by early this evening. This low will then intensify as it
moves into sern co by 12z Tue and then become vertically stacked.
At the sfc, currently there are two low's with one SE of denver
while the main low is south of pueblo. Eventually the low over
sern co will become the dominate feature.
Overall there will be favorable mid level ascent across the entire
area both today and tonight with NRN co being in the favorable
position of the upper level jet. Soundings are generally moist
adiabatic thru the period. Thus should see showers and tstms become
more widespread through the day. Believe threat of svr storms is
low over sern portions of the area due to lack of heating, however,
can't completely rule out a marginal elevated severe storm. As
for temps, with considerable low cloud cover and expected pcpn,
readings may stay mainly in the 40's across nern co except over
far sern areas where lower to mid 50's may occur. Meanwhile highs
near the wy border may not even get above 40.
For tonight, as the main upper level low intensifies and moves into
sern co will continue to see additional rain and a few storms
over nern co. Across the higher terrain, not exactly sure how
things are going to evolve. The mid level flow is generally
southerly this evening which isn't real favorable for precip,
however, after midnight it does become more favorable. Thus
heavier snowfall may not occur until then.
At lower elevations, precip could change to snow over the palmer
divide this evening with snow levels down to 6500 feet. Meanwhile|
overnight the ecmwf, NAM and caic WRF have temps becoming cold
enough for snow between midnight and 3 am down to around 5000 feet.
Overall there could end up being advisory type amounts over the
palmer divide abv 6500 feet and possible near the wy border in zn
38, however confidence isn't high since we are in the 3rd week of
may. Meanwhile could see an inch or so of snow on grassy areas by
12z Tue across some areas of the front range urban corridor if
precip does change to all snow by 09z.
Long term (Tuesday through Sunday)
issued at 509 am mdt Mon may 20 2019
upper troughing will be in place for the CWA on Tuesday with a
closed circulation over southeast colorado at 12z Tuesday morning.
This feature is over southwestern nebraska at 00z Tuesday
afternoon. There will be a bit of weak upper ridging for the cwa
Tuesday night. On Wednesday strong southwesterly flow aloft moves
over the cwa. This continues Wednesday night. There is strong
upward motion over the CWA on the QG omega fields on Tuesday.
Downward vertical velocity is in place Tuesday evening through
Wednesday. Upward energy is progged Wednesday night. The level
winds are northerly upslope all day Tuesday and Tuesday evening.
Weak drainage patterns may kick in late Tuesday night. East and
northeasterly low level winds are progged Wednesday and Wednesday
night. For moisture... There is quite a bit over the CWA on Tuesday
and Tuesday evening, the deepest is over the mountains. The airmass
dries out later Tuesday night somewhat. Moisture increases again
by late Wednesday morning into Thursday. There is minor cape
around on Tuesday, mainly in the mountains. Same for Wednesday.
For pops, will keep in or go with 60-90%s on Tuesday for most of
the cwa. Will decrease them Tuesday night, more so over the plains
and keep "chance"s going in the mountains all night. Will go with
"likely"s in the mountains on Wednesday Wednesday night and
"chance"s over the western half of the plains for those periods.
Tuesday's precipitation should be a decent stratiform event with
widespread coverage for all the cwa. Snowfall amounts in the
mountains and foothills are still in line with the highlights on
Tuesday. For the plains on Tuesday morning before 18z, there is
some snow mixed in over the western areas and certainly all snow
for the palmer and cheyenne ridges. For temperatures, Tuesday's
highs will be similar to today's highs. Wednesday's readings will
be 1-4 c warmer. For the later days, Thursday through Sunday,
models have a mean trough over the western unites states and a
closed low centered over northern utah. Our CWA stays is strong
southwesterly flow aloft on Thursday. The southwesterly flow aloft
weakens some by Friday but is still fairly strong through the
weekend. Pops will be limited and mainly of the later day variety
in the mountains. Temperatures will stay cooler than normal on
Thursday, then warm up to around normal for Friday through Sunday.
Aviation (for the 18z tafs through 18z Tuesday afternoon)
issued at 941 am mdt Mon may 20 2019
a strong storm system will move across the rockies today and
Tuesday. Low clouds with ceilings of 500 to 1000 feet are expected
to prevail through 18z Tuesday. Light rain will continue this
morning and increase in intensity by midday. Thunderstorms will be
possible, with the best chance being 20z to 02z. Periods of
showers will continue tonight. Temperatures will slowly fall this
evening with rain changing to snow around or a little before
midnight. Up to 2 inches of snow may fall on grassy areas. A thin
slushy accumulation may occur on paved surfaces under isolated
higher intensity showers.
Bou watches warnings advisories
Winter weather advisory from 6 pm this evening to midnight mdt
Tuesday night for coz036.
Winter storm warning from 6 pm this evening to midnight mdt
Tuesday night for coz035.
Winter storm warning until midnight mdt Tuesday night for coz031-
short term... Rpk
long term... .Rjk
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|ELLICOTT-B AFA, CO||18 mi||29 min||NE 10 G 28||mi||Thunderstorm Heavy Rain||0°F||0°F||%||1007.8 hPa|
Wind History from ABH (wind in knots)
|1 day ago||E|
|2 days ago||W|
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