Thursday, February21, 2019 L-36.com


Marine Weather and Tides
Princeton, TX

Version 3.4
What's New / NOTES
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 7:02AMSunset 6:17PM Thursday February 21, 2019 3:49 PM CST (21:49 UTC) Moonrise 8:52PMMoonset 8:39AM Illumination 94% 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
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7 Day Forecast for Marine Location Near Princeton, TX
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location: 33.15, -96.49     debug


Area Discussion for - Fort Worth, TX
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Fxus64 kfwd 211800
afdfwd
area forecast discussion
national weather service fort worth tx
1200 pm cst Thu feb 21 2019

Aviation
18z tafs
precipitation continues to shift slowly north and east of the
area along with the disturbance responsible for it. The
possibility of additional thunderstorms has dropped considerably
as the stronger forcing for ascent appears to have already exited
to the northeast. Vcts will remain in the dfw metroplex tafs for
another hour, followed by vcsh until 22 00z.

Meanwhile, an upper level low continues to deepen across the
desert southwest while a stationary front remains parked along the
gulf coast. The resulting pattern will lead to strengthening
isentropic lift and deteriorating flight conditions area-wide
tonight through Friday. MVFR ceilings will arrive early this
evening with conditions likely dropping to ifr prior to midnight
local tonight. Visibility reductions will become possible by
sunrise Friday as areas of drizzle and fog develop. Little
improvement can be expected during the day Friday, with ifr
conditions continuing through the end of the forecast period.

A round of showers and storms will sweep through Friday night,
with a return toVFR conditions Saturday. On a side note: strong
west winds on Saturday may result in cross-wind issues and
reduced arrival rates at dfw (thanks to the cwsu for
coordination).

30

Update issued 1009 am cst Thu feb 21 2019
scattered showers and isolated thunderstorms will continue over
parts of north and central texas through early afternoon.

Convection is elevated in nature with cloud bases around 8000 ft.

Thunderstorms have produced numerous reports of small hail (pea to
smaller than pea sized), likely due to the cool dry air in place
at the lower levels of the atmosphere allowing hydrometeors to
remain at least partially frozen. The disturbance responsible for
this mornming's activity will lift northeast of the area this
afternoon, which will bring a gradual end to this round of
precipitation from west to east. The forecast has been updated to
expand the area of isolated thunder west along the i-20 corridor
through early afternoon, otherwise the grids are in good shape.

Another round of showers is still expected tomorrow, with the main
round of showers and storms occurring Friday night as an upper
trough and a cold front move across texas and the southern
plains.

30

Short term issued 443 am cst Thu feb 21 2019
today and tonight
splotchy radar echoes racing through central and east texas are
evidence of a mid-level impulse embedded in southwest flow aloft.

These elevated convective elements are based well above 10kft,
and with a very dry sub-cloud layer, this virga can only be seen
on the radar scope. It's only along the coastal plains, where
low-level moisture has already returned, that deeper convection
(with some embedded thunder) has been able to yield rainfall at
the surface. While this moisture will endeavor to advance further
inland today, the backed low-level flow will make this an arduous
effort. As a result, the swifter impulse will gradually separate
from this inflow later this morning. Although radar echoes will
become increasingly more numerous after daybreak, particularly
east of i-35, the dry air beneath will reduce them to sprinkles.

Our counties within central and east texas, where the moisture
depth will improve, will have the greatest potential for
measurable rainfall. However, the intensity of the forcing aloft
may be sufficient for showers deeper into north texas. The
activity will diminish late in the day on the backside of the
exiting disturbance. Even without widespread rainfall, the
considerable cloudiness today will prevent high temperatures from
reaching Wednesday's values.

While too late to help our rain chances today, low-level moisture
will rapidly return this evening. The lowest few thousand feet of
the atmosphere will steadily saturate tonight, resulting in
drizzle and fog during the early morning hours Friday. This will
limit the temperature drop overnight, and some locations in
central and east texas may only fall a few degrees between
Thursday afternoon and daybreak Friday.

25

Long term issued 443 am cst Thu feb 21 2019
Friday through Wednesday

Chances for severe weather increase for the start of the
weekend...

an active weather regime will continue for the end of the week
into the beginning of the weekend (Saturday) as a vigorous mid-
level trough continues deepening over the southwest deserts and
northern mexico. On Friday, this system will only slowly move
eastward as a balanced and very strong 125-145 knot 250mb upper
jet MAX enters the southern base of the system. Warm advection
within the 925mb-850mb layer will begin in earnest over the
shallow cold dome of air at the surface across north and central
texas through the day. In addition, the left exit region of the
aforementioned upper jet MAX will arrive and coincide with the low
level warm advection associated with a lead shortwave for an
increase in showers and thunderstorms across particularly central
texas Friday morning, before shifting to areas mainly along east
of i-35 Friday afternoon and evening as better large- scale
forcing with the lead shortwave lifts toward east texas and the
lower mississippi valley. This is the time period where north and
central texas sees a brief lull in the elevated convective
activity. Lastly, the warmer strip of air overriding the cool
surface layer will result in occasional patchy drizzle and light
fog.

As noted in yesterday's early morning discussion and not to be
understated with the cool and stable surface conditions, a few
strong storms containing hail and more frequent lightning will be
possible Friday. Lapse rates aloft pushing 7 deg c km within the
the 650mb-475mb layer and westerly deep layer shear on the order
of 40-60 knots depending on which model you believe. As a side
point, namnest point soundings indicate another layer of steep
lapse rates between 875mb-725mb. If not for a warmer and more
stable layer in between around 700mb, updraft maintenance and
strength would likely be greater and warrant at least a low threat
for quarter hail, considering the aforementioned deep layer shear
and ascent. For now, too many uncertainties regarding the
elevated instability exists for more than a mention of a few
strong storms and small hail lightning on Friday. This will be
monitored closely in subsequent forecasts.

The stormy, wet, and dreary forecast continues overnight Friday
night and into Saturday morning, as our main mid level disturbance
begins negatively lifting northeast over new mexico and the
texas oklahoma panhandles through Saturday morning. If not for
the majority of the area remaining contained within a cooler and
stable surface layer, i'd be more concerned regarding severe mode
and hazards as ascent really gets going with lapse rates aloft
steepening to between 7-8 deg c km and southwesterly deep layer
shear between 60-70 knots. Fortunately, the progressive
negatively-tilted nature of the system and its increasing speed
and northeast track toward kansas oklahoma will not allow much
time for the warmer and unstable surface-based air across
southeast texas and the upper texas coast to get too far into our
area in advance of an eastward moving dryline on Saturday.

From what I can establish from the models, the main window for
any severe weather is 2 and 10 am Saturday morning, mostly along
and east of i-35 where a potential for a modified warm sector
with SBCAPE between 500-1000 j kg "may" set up south of i-30 and
east of i-35 across central texas. Furthermore, the undesirable
time of day and coverage of convective activity in advance of the
dryline will have its say on if this warm sector instability is
actually realized. At this time, the better set up and higher risk
for severe weather should be to the east and northeast of north
and central texas. It's been quite a time since we've seen this
magnitude of a kinematic setup with such an unstable thermodynamic
environment aloft. All that said, I cannot argue with the spc
marginal risk along and east of i-35 later Friday night through
midday Saturday. Large hail, frequent lightning, locally heavy
rainfall, and potentially very gusty downburst winds will be
possible across the eastern counties where my highest confidence
currently lies. However, if this system were to slow down, that
would allow more surface airmass modification across our far east
and southeast counties. That would definitely raise a concern for
a broader mode of threats with regard to damaging winds and even
a tornado or two.

Our main vigorous disturbance will continue its progressive
northeast track Saturday afternoon and through the remainder of
the weekend. Strong west or west-northwest winds will transition
quickly eastward as a unidirectional westerly component sets up
through 850mb. West winds 15-20 mph with gusts 30-35 mph will
likely set up for a potential wind advisory for at least the
northwest half of the region later in the day. In addition,
humidity values will drop rapidly with a potential for elevated
fire weather conditions across the western counties. A cold front
arrives into the area by Saturday evening, shifting winds to the
northwest, then north and remaining brisk at 10-20 mph with a
chilly start in the 30s Sunday morning. However, high pressure
will settle in during the day Sunday helping to diminish the
winds with plentiful sunshine expected within the dry continental
airmass. Highs will range from the 50s north to the lower 60s
across central texas Sunday afternoon.

A gradual transition to warmer, breezier, and slightly more humid
conditions is expected during the early part of next week as we
await a couple of strong cold fronts around the middle of the
week. After highs mostly in the 60s Monday and Tuesday, I followed
the more aggressive european model regarding the next cold air
intrusions with a return to more of a late winter feel. Brisk
north winds will combine with cooler than normal temperatures,
requiring a jacket or coat. Luckily, the main storm track looks
to shift more north and east of our region with strong, dry,
nearly zonal flow over the south central conus. A few
disturbances rippling overhead may result in a low chance for a
few showers, but nothing of significance.

05

Preliminary point temps pops
Dallas-ft. Worth 53 44 55 51 66 40 20 60 80 60
waco 53 46 59 52 67 40 40 60 80 50
paris 51 42 52 51 64 50 30 70 80 90
denton 52 43 53 49 63 30 20 60 70 50
mckinney 52 43 53 51 64 40 20 70 80 70
dallas 53 46 55 52 67 50 20 70 80 60
terrell 53 45 56 52 67 50 30 70 80 80
corsicana 53 46 57 52 67 50 50 70 80 80
temple 54 47 59 52 68 30 40 60 80 50
mineral wells 54 43 55 47 63 20 20 30 70 30

Fwd watches warnings advisories
None.

30 91


Weather Reporting Stations
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Airport Reports
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AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
McKinney - McKinney National Airport, TX6 mi57 minESE 9 G 1810.00 miOvercast48°F39°F74%1016.5 hPa
Dallas / Addison Airport, TX22 mi63 minE 15 G 2110.00 miOvercast50°F37°F62%1014.9 hPa
Greenville / Majors, TX23 mi80 minESE 910.00 miOvercast50°F42°F76%1016.3 hPa

Wind History from TKI (wind in knots)
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Last 24hrE3SE8SE7SE7SE4E4E3CalmCalmE4S3E5NE4E4E4N5SE5CalmSE5E7E11E8E16
G21
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1 day agoNE8N6NE6N7N3NE4N6NW4NW3NW4W6W12NW8NW12NW9W5W6W6SW7W10SW6W8CalmCalm
2 days agoNE9NE9NE9N9NE8NE7N8NE7NE8NE9NE10NE11NE9E10NE8E8NE5NE6E5E8CalmNE4NE7E9

Tide / Current Tables for
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Weather Map and Satellite Images
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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.
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Wind Forecast for Fort Worth, TX (16,3,4,5)
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Ground Weather Radar Station Dallas/Fort Worth, TX
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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.