Saturday, February17, 2018 L-36.com


Marine Weather and Tides
Pell City, AL

Version 3.4
What's New / NOTES
6/25/2017 - NOAA is having a major issue that impact the 7 day forecast load times. Many users are reporting problems. The issue has been reported.
5/23/2017 - Worked with NOAA again to speed up the 7 day forecast load times. Thanks to them for being responsive.
5/19/2016 - There were issues with the 3 day airport observation history. I switched to another data source. Let me know if you see any issues with the data feeds.

Sunrise 6:23AMSunset 5:32PM Saturday February 17, 2018 8:43 PM CST (02:43 UTC) Moonrise 8:36AMMoonset 8:23PM Illumination 8% Phase: Waxing Crescent; Moon at 3 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 Pell City, AL
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location: 33.61, -86.29     debug


Area Discussion for - Birmingham, AL
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Fxus64 kbmx 180011
afdbmx
area forecast discussion
national weather service birmingham al
611 pm cst Sat feb 17 2018

Update
For 00z aviation.

Synopsis
Goes-r water vapor and global numerical models both depict the
center of a broad mid layer ridge remaining over the central gulf
of mexico. The ridge has become more elongated zonally over the
past 48 hours, allowing our forecast area to experience a series
of shortwave disturbances in the general southwest flow to the
north of the ridge.

Toward the surface, a cold front that moved into the state
yesterday afternoon stalled over our southern counties early this
morning and since has retreated northward as a warm front and is
now located over the tennessee valley region. A very weak
influence by surface high pressure off the coast of new england
down the appalachians resulted in a weak easterly flow across our
east-central and northeastern counties this morning into early
afternoon that resulted in lower dew points and slightly cooler
temperatures. This influence has largely been mitigated at this
hour by vertical mixing.

A pronounced frontal inversion was present on the 17 12z bmx
sounding this morning up to near 935 mb followed by a near
saturated region up to near 745 mb with a strong subsidence
inversion that extended further aloft to just beyond 350 mb. A
light low level easterly flow quickly veered to the south around
970 mb and increased to near 10 kts followed by a unidrectional
southwest flow from around 895 mb that extended further aloft to
near 170 mb. Highest measured winds were around 110 kts from zonal
flow around 150 mb.

05

Short term
Today and tonight.

A shortwave trough in the southwest flow aloft is supporting the
southeast advance of the cold front that returned north this
morning. The front is approaching our far northwest counties at
this hour and will result in higher rain chances expanding
southeast across our forecast area later this afternoon and into
tonight.

Similar to yesterday, temperatures will fall at least 10 degrees
with the frontal passage with a wind shift from the north-
northwest upon arrival. Ahead of the front, vertical mixing has
helped to reduce cloud cover and is promoting breezy conditions at
times as regional VWP data shows near 50 kt retrievals around 5000
ft. Breezy conditions will remain possible through sunset for
areas ahead of the cold front before vertical mixing subsides.

The southwest flow pattern aloft with limited amplitude will
continue to keep the cold front from clearing our forecast area
tonight with the boundary likely decelerating this evening and
stalling across the southern third of our forecast area overnight.

The front is expected to again lift northward early on Sunday as a
warm front.

A pronounced thermal gradient will again be present across our
forecast area overnight with lows in the low to mid 40's tonight
with colder readings across our northwest counties. Meanwhile,
readings will only fall to the lower 60's across our far southeast
counties as the front stalls to the north of these locations.

05

Long term
Sunday through Saturday.

The back and forth battle between a ridge to our southeast and
the troughing to our north continues through the next 7 days. A
couple of shortwaves move through pushing cold fronts into the
area. Each will stall somewhere in south-central or southern al
before lifting back northward as an effective warm front thanks to
the ridging. This will lead to a continuous cycle of rain chances
across central al.

First up on Sunday is the cold front that pushed into south al
earlier this weekend. It will be lifted back northward as a warm
front increasing rain chances Sunday afternoon across much of the
area ahead of the deepening shortwave trough to our northwest. We
could see a break in the rain activity Monday and Tuesday as we
remain in the warm sector with the cold front off to our west
moving through the ozarks.

The next cold front is expected to push into the area around mid-
week, but the exact timing is uncertain. The GFS is at least 24+
hours more progressive with the front and best rain chances getting
into central al compared to the ecmwf. Both have the front
essentially stalling Wednesday night into Thursday, but the ec has
it slowing stalling just to our north and west while the GFS has it
stalling in central to south al.

Models keep this front stalled through Thursday night Friday morning
before it's lifted back north as an effective warm front, though
just how quickly it gets lifted is still questionable. Overall,
model differences in timing of this next front on Wednesday and
where it slows down stalls makes the forecast for the second half of
the week difficult. I've carried 60-70% chance of rain for Wednesday
north of the i-20 corridor, but have decreased the pops to 50% on
Thursday simply due to the uncertainty of where that front will be
located. I have also included mention for thunderstorms Wednesday
and Thursday due to instability that will be in place across the
area. 0-6km shear values are 20-25kts - too low to support any
organized severe threat, therefore I will not add mention in the
hwo. Thursday night into Friday, i've kept lower pops (25-30%)
leaning more towards the ECMWF solution of pushing the warm front
north of the area and keeping us mostly rain-free. The 25-30% is
accounting for the potential of the GFS solution for rain
continuing through the end of the week.

By this coming weekend, models hint at yet another shortwave
moving through the trough, and pushing another cold front into the
area, but the timing is just beyond the 7 day forecast, so have
just included chance pops in for Saturday.

25 owen

Aviation
00z TAF discussion.

Pesky frontal system will keep restrictive categories at the
terminals at least the first 12 hours, and may be too optimistic
thereafter. Timing will be an issue.

The front, now a cold front, has just passed tcl bhm and was
approaching eet anb asn. A fine line of showers was near the front
with ifr ceilings. Then there is a break in the shower activity
and ceilings, followed by more light showers and ifr ceilings.

Tried to indicate this sequence in the terminals as best as
possible. These clouds will arrive near mgm toi around 06z, but
once again, that is about it on the push southward especially just
above the surface.

Winds will swing back around to a southerly direction and clouds
will likely redevelop on Sunday, probably MVFR. These line breaks
will be added in the next forecast. Otherwise, as the front moves
by, winds shift to the northwest and north around 10kts and a bit
gusty. The winds relax later this evening.

Needless to say, there will be up and down periods this forecast
cycle with the front moving south and then north.

75

Fire weather
Rain showers are forecast tonight through Sunday as a front arrives
from the northwest and stalls across our southern counties
overnight. Above normal dewpoints will preclude any fire weather
concerns through at least the next week.

Preliminary point temps pops
Gadsden 45 64 54 74 57 90 40 30 20 10
anniston 48 65 56 76 58 80 30 30 20 10
birmingham 47 64 58 77 60 90 30 20 20 10
tuscaloosa 49 64 58 77 61 90 40 10 20 10
calera 49 65 58 78 60 80 30 20 20 10
auburn 55 67 59 77 60 60 30 10 10 10
montgomery 55 71 59 81 60 60 20 10 10 10
troy 60 73 58 80 60 30 10 10 10 10

Bmx watches warnings advisories
None.



Weather Reporting Stations
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Airport Reports
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AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
Anniston Metro Airport, AL23 mi51 minWNW 89.00 miLight Rain64°F60°F87%1020.1 hPa

Wind History from ANB (wind in knots)
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Last 24hrN4N5NE5N7NE3NE5NE5E6NE7NE8NE7NE8NE7NE4CalmSW18
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SW11--SW3W7W8
1 day agoSW10
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2 days agoNE3CalmN3N3CalmCalmCalmCalmCalmSW5SW7SW6SW8SW7
G16
SW8SW9SW8SW10
G20
SW11SW7S8S5S3SW5

Tide / Current Tables for
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Tide / Current Tables for
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Weather Map and Satellite Images
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Weather Map
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IR Satellite Image from GEOS
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GOES Local Image of Southeast    EDIT
Geos

Wind Forecast for Birmingham, AL (21,6,7,8)
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Ground Weather Radar Station Birmingham, AL
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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.