Wednesday, June19, 2019 L-36.com


Marine Weather and Tides
Big Sky, MT

Version 3.4
NOTICE
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 5:32AMSunset 9:18PM Wednesday June 19, 2019 11:25 AM MDT (17:25 UTC) Moonrise 10:22PMMoonset 6:41AM Illumination 95% Phase: Waning Gibbous; Moon at 17 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
    EDIT      (on/off)   Help


7 Day Forecast for Marine Location Near Big Sky, MT
   Hourly   EDIT   Help
location: 45.26, -111.31     debug


Area Discussion for - Great Falls, MT
      (on/off)   Help   NOTE: mouseover dotted underlined text for definition
Fxus65 ktfx 191603
afdtfx
area forecast discussion
national weather service great falls mt
1003 am mdt Wed jun 19 2019

Synopsis
Isolated to scattered showers and thunderstorms will pick up again
this afternoon along parts of northcentral and southwest montana,
and persist into the evening hours. Windy conditions are expected
as well today for locations along the rocky mountain front and
northcentral plains through this evening. Then much cooler and
unsettled weather moves in for Thursday into the weekend. Expect
increasing chances for showers, with some snow possible over
mountain locations Thursday night into Friday.

Discussion
Morning update has been published. Large scale height falls of 100-
150m were pushing east southeast across the northern rockies this
morning as a potent upper level trough was digging into the region.

At the surface, low pressure was beginning to move east northeast
from southern alberta, with a pacific front sliding east southeast
from the pacific northwest southwest canada and towards the northern
rockies. The aforementioned cold front will begin to cross north
central and southwest montana by late this morning, clearing far
eastern portions of the CWA by the late afternoon early evening
hours. Breezy conditions have already developed across most of the
region thanks to a stout h700 jet of 20-40kts orientated
perpendicular to the continental divide and diurnal mixing, with
wind speeds expected to see a further uptick as the cold front
crosses the region this afternoon. Dry air is also overpreading the
cwa this morning thanks to the dry, downsloping southwest westerly
winds, with miniumum relative humidity values expected to fall into
the upper teens to around 30 percent. The combination of the breezy
winds and low relative humidity values will lead to elevated to near-
critical fire weather conditions, however, feedback from local
experts indicate that fuels remain too wet green for large fire
spread. Thus, have and will continue to hold off on any fire weather
highlights for today. As the cold front crosses the region, expect
showers and thundestorms to develop, especially over the higher
terrain where uneven surface heating will provide additional lift in
conjuction with the increasing synoptic lift. These showers and
thunderstorms are expected to be isolated to scattered in nature,
with the one expcetion being near the idaho wyoming borders, where
showers and storms will be more numerous in coverage. While a strong
storm producing small hail and gusty winds (outside of the general
winds) can not be ruled out, expect most thunderstorms to be of the
garden variety do to a non-proportional combination of bulk shear to
instability (i.E. Shear will be so strong today that it will likely
shred storms apart given the marginal instability). - moldan

Aviation
Updated 530 am mdt Wed jun 19 2019 (19 12z tafs)
vfr conditions prevail throughout this forecast period, with the
exception of potentially MVFR conditons under thunderstorms and
showers that develop this afternoon and evening. Expect gusty
westerly winds with the strongest winds along the rocky mountain
front and adjacent plains today. -tp

Prev discussion
Issued 530 am mdt Wed jun 19 2019
a trough approaches from the west and begins to move through our
area. The associated strong cold front passes through the treasure
state from the west-northwest to the east-southeast. Instability,
lift and moisture will continue to favor thunderstorm activity.

The storm prediction center (spc) has placed a marginal risk of
severe weather along the eastern boarder of our southwest montana
forecast area. Following cold frontal passage, fire weather
concerns are expected to be elevated to near-critical. Please, see
our fire weather forecast for more information. The unseasonably
cold mid-level trough becomes cut off from the general circulation
as it dives southeast into the state later today and into
Thursday early morning. -jaf tp
Thursday through Tuesday... Expect a fairly significant drop in
temperatures on Thursday, with the cool temperatures expected to
persist through much the weekend. Currently it looks like Friday
will be the coolest day during this period. Wetter conditions
begin to ramp up over the area on Thursday, and it appears that
the most significant precipitation will fall sometime late
Thursday into Friday. The areas along the rocky mountain front
and over portions of north & central montana are likely to see the
bulk of this rainfall, which may cause areas of excessive runoff.

As the cooler temperatures filter in, snow levels may fall as low
as the 5500 to 6500 foot level late Thursday into Friday,
allowing for some snow to fall and potentially accumulate at
higher elevation locations such as glacier national park, king's
hill pass. This is highly dependent on whether the snow falls
during a time period influenced by diurnal heating but either way,
the biggest impacts from snow are expected to be limited to those
with outdoor recreation plans or forest service activities in
mountain areas. Due to forecast uncertainty, some refinement will
be likely in terms of locality and rainfall snow amounts as
details become clearer in the coming days. By Saturday, the trough
is expected to lift northeast as general flow becomes more zonal.

Pops drop off a bit later Saturday into Sunday, although isolated
to scattered showers and thunderstorms remain possible into early
next week. Expect a slow warming trend Sunday through Tuesday,
ahead of the next disturbance progged to move in from the pacific
northwest late Tuesday into Wednesday. -rcg tp

Preliminary point temps pops
Gtf 74 43 62 42 20 20 40 50
ctb 69 40 59 41 30 20 50 40
hln 76 44 62 41 10 10 50 40
bzn 73 39 62 38 50 20 50 70
wey 65 32 56 28 100 50 40 70
dln 70 37 57 35 20 10 50 50
hvr 77 44 64 42 30 30 40 30
lwt 71 40 59 39 20 20 50 60

Tfx watches warnings advisories
None.

Http:

Weather Reporting Stations
   EDIT       (on/off)   Help   NOTE: Click on distance to see the station location on a map

Airport Reports
    EDIT      (on/off)   Help   Click EDIT to display multiple airports
AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
Bozeman, Gallatin Field, MT38 mi30 minN 810.00 miFair64°F46°F54%1007.8 hPa

Wind History from BZN (wind in knots)
12
PM
1
PM
2
PM
3
PM
4
PM
5
PM
6
PM
7
PM
8
PM
9
PM
10
PM
11
PM
12
AM
1
AM
2
AM
3
AM
4
AM
5
AM
6
AM
7
AM
8
AM
9
AM
10
AM
11
AM
Last 24hr46N21
G32
NE11N6CalmCalmS5E3E4SE6SE3SE6SE6S4S5S6S6CalmSE6CalmCalm3N8
1 day ago3CalmNW5W5NW7NW11E8SE3S7N13
G30
NW10S8E4N4S5S3SE4CalmE5S3E4SE5CalmCalm
2 days agoW5N63CalmN3W74S9
G20
SE15SE7SE3SW3S5NE4S3NW4NW3SW4CalmCalmCalmCalmN5N4

Tide / Current Tables for
   EDIT   Weekend mode (on/off)   (on/off)   Help
Tide / Current Tables for
   EDIT      (on/off)   Help
Weather Map and Satellite Images
       (on/off)   HelpWeather Map
wmap_P
GOES 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 Great Falls, MT (13,3,4,5)
      (on/off)   Help

Ground Weather Radar Station Billings, MT
   (on/off)   Help
weather_mapweather_map weather_map

Ad by Google

Disclaimer:
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.