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Re: February 2020

Posted: Fri Feb 14, 2020 5:02 am
by unome

Re: February 2020

Posted: Fri Feb 14, 2020 7:59 am
by srainhoutx
Friday morning weather briefing from Jeff:

Cold surface high located over NE/E TX this morning with clear skies across SE TX.

Light winds and clear skies overnight has allowed enough cooling for Caldwell and Huntsville to fall to 31 so far this morning with elsewhere falling into the 30’s and 40’s. Southerly winds and developing clouds are already noted across west TX and as the E TX surface high moves eastward clouds will begin to increase late tonight into Saturday…enjoy the sun today…because it looks like at least 5-7 days of clouds, fog, and light rain starting on Sunday.

Moisture increases along the coast on Saturday and expect skies to become mostly cloudy by late afternoon with cloud cover spreading inland from the coast. Saturday morning will be cold with similar temperatures as this morning, but increasing warm air advection during the day Saturday will result in highs a good 10 degrees warmer than today. Dewpoints begin to come up Saturday night into early Sunday and expect at least patchy sea fog to begin to form with chances increasing through the day on Sunday. A passing disturbance in the developing SW flow aloft will also support a 20-30% chance of showers late Saturday night into Sunday with the most favored locations near the coast.

Warm air advection will be in full force Sunday-Tuesday with temperatures well into the 70’s…possibly a couple of 80’s around Matagorda Bay if the sun can break through the overcast. Dewpoints will be several degrees over nearshore temperatures by Monday and expect a widespread and extensive sea fog bank along much of the TX coast late Sunday-Tuesday evening. Sea fog will spread inland each evening and the coastal sites may not break out at all during the day with visibilities bouncing between 1/8th a mile and 2 miles. Vessel traffic into Galveston Bay and the Houston Ship Channel will likely be impacted. There will be a chance of showers each day, but similar to last week expecting more fog and drizzle than actual rainfall accumulations.

A shallow cold front will move into the area Tuesday night into Wednesday morning and a cold air mass will put into the region. This front will end the threat of sea fog…at least for a few days. Expect highs on Tuesday in the upper 70’s to be replaced with highs falling through the 40’s on Wednesday. Stout inflow of warm moist air over the frontal inversion looks to result in decent and sustained lift over all of the area Wednesday and Thursday and will go with high rain chances both days. Widespread rains are likely during this period, with the ECMWF and CMC showing SE TX bearing the brunt of the rainfall while the GFS showing the greatest amounts further inland over NC/C TX. Lots of time to sort out all the details with rainfall amounts.

Area really never clears out even after Thursday as moisture remains in place…surface temperatures will begin to warm as a warm front moves into SE TX a week from today…and the pattern repeats with fog, drizzle, and showers into next weekend.

History:
Today is the 125th anniversary of the biggest recorded snowfall event in SE TX. Houston measured 20 inches and Beaumont 28 inches from the development of a coastal low over the NW Gulf of Mexico and the intrusion of a cold arctic air mass. All of SE TX experienced snow with this event and in fact snow was reported at nearly every location along the US Gulf coast from Brownsville to the FL panhandle. Brownsville, TX would not record snow again until Christmas Eve 2004 or 109 years later. Snow drifts in Chambers and Jefferson Counties were reportedly 4-6 feet high.

The link below has a few quotes from newspapers and pictures from the event:

http://wintercenter.homestead.com/photo1895.html

Re: February 2020

Posted: Fri Feb 14, 2020 9:00 am
by Cpv17
I would take a repeat of this in a heartbeat. Unfortunately for me, that’ll never happen here again.

Re: February 2020

Posted: Fri Feb 14, 2020 12:44 pm
by tireman4
00
FXUS64 KHGX 141734
AFDHGX

Area Forecast Discussion
National Weather Service Houston/Galveston TX
1134 AM CST Fri Feb 14 2020

.AVIATION [12Z TAF Issuance]...

VFR conditions are expected to continue through the remainder of
the TAF period. Should see northeast winds around 10 knots through
the afternoon, becoming lighter and variable during the evening
hours. While the development of sub-VFR cigs does not look to
be a concern over the next 24 hours, a shift of winds to the
southeast tomorrow will begin to supply moist Gulf air back into
the region and some lower scattered clouds should develop by
tomorrow morning as a result. MVFR to IFR cigs look to develop by
Saturday evening with continued onshore flow.

Cady

&&

PREV DISCUSSION /Issued 401 AM CST Fri Feb 14 2020/...

DISCUSSION...

- Cool/dry today with high temperatures in the upper 50s/low 60s.
- Warmer and more humid Saturday through Tuesday. Sea fog possible
Monday and Tuesday.
- Shallow cold front pushes through the area late Tuesday with
isentropic lift over the front for a wet Wednesday/Thursday.

SHORT TERM [Today Through Saturday]...

With high pressure dominating the area, weather will be quiet
through today and tomorrow. The high pressure center will be
moving east of the region, so expect winds to veer through
northeasterly to easterly in this time. This will modestly help
increase low level moisture content, particularly right on the
coast. This should help bump overnight lows tonight/early Saturday
morning up into the 40s at the coast, and at least more towards
the middle 30s farther inland. Similarly, look for more seasonable
temperatures on Saturday afternoon compared to a cooler day
today.

That`s it. That`s the discussion. For more interesting weather,
please read on to the long term section.

Luchs

LONG TERM [Sunday Through Friday]...

Here`s the more interesting weather section where we talk about
dprog/dt plots and frontogenetic lift...

Sunday looks to be the day for stronger return flow off the Gulf
as a short wave trough is expected to quickly pass across the
plains. Models have varying degrees of intensity with wave, but
the impacts are about the same. There may be a weak coastal trough
to set up and push inland Sunday which brings a low chance of
showers. Otherwise models have relatively backed off on a wet
scenario that was present earlier in the week.

The upcoming week looks to have a return to spring followed by
wanna be winter. Temperatures warm up into the 70s or about 10
degrees above normal. With that, low temperatures will be a good
15 degrees above normal for most areas as dewpoints rise into the
60s. This will set up the possibility of more sea fog along the
coast Sunday through Tuesday. As we go through the weekend, we
may need to add this to the weather grids to further communicate
confidence in its occurrence which is tricky to forecast.

Looking at some dprog/dt plots for 500mb height/vorticity trends
of the GFS shows that the pattern has shifted to a more
zonal/progressive pattern for Monday through Thursday than in
previous runs. This means that generally it will be hard for any
cold fronts to push into the area given this pattern but the
pattern does maintain some amplification over the Pacific NW with
a broad ridge and a short wave trough developing over the
Intermountain west on Monday. This trough had been progged to dig
farther south but instead begins to shoot east into the Plains on
Tuesday as the ridge amplifies over the Pacific NW. We still have
some zonal flow over the area due to the southern branch of the
jet that then phases with the northern branch on Tuesday.
Amplified pattern now over Canada is enough support for a cold
front to move through the area late Tuesday. This sets up for a
period of enhanced isentropic lift over the front Wednesday into
Thursday. We decided to go with 60/70 PoPs during this time as
this looks to be when isentropic lift at 300k looks strongest and
frontogenetic lift looks strongest in the 925mb-850mb layer as
well as 850mb-700mb layer. There looks to be 1.4 to 1.5 inches of
precipitable water over the area around this same time which
should support some decent rainfall totals where lift can be
maximized. The trick now is narrowing down details on the mesocale
of where some of these bands of heavier precip set up and it is
just too early in the forecast cycle to nail down those details.
Right now both the GFS/ECMWF/Canadian 3 different locations of
precip with GFS farther north over central Texas and the Arklatex.
ECMWF and Canadian are farther south mover over SE Texas. At most
we are looking at 1 to 2 inches of rain for the event but more
likely closer to 0.5 to 1 inches of rain. This kind of rain may
not end drought conditions but at least help ease it some.

Overpeck

MARINE...

Caution flags will remain posted across the coastal waters
overnight as a moderate to strong offshore flow persists. There
are some small craft-level observations, but all have come at
elevated sites, and suspect that closer to the water, caution-
level winds are more likely. Wind speeds are expected to taper
off slowly towards tonight. Winds will become increasingly
onshore this weekend. This will begin an influx of warmer and more
moist Gulf air, and the development of marine fog will once again
be possible from early Sunday, persisting through Tuesday. A cold
front later on Tuesday will a shift in winds to offshore, and end
any sea fog threat.

Luchs

&&

.PRELIMINARY POINT TEMPS/POPS...
College Station (CLL) 38 65 51 75 59 / 0 0 0 0 10
Houston (IAH) 41 65 55 74 60 / 0 10 20 10 10
Galveston (GLS) 53 63 59 67 62 / 0 20 40 20 10

&&

.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT SHOULD EXERCISE CAUTION through this evening for the
following zones: Coastal waters from Freeport to Matagorda
Ship Channel TX out 20 NM...Coastal waters from High Island
to Freeport TX out 20 NM...Waters from Freeport to
Matagorda Ship Channel TX from 20 to 60 NM...Waters from
High Island to Freeport TX from 20 to 60 NM.

&&

$$

Discussion...99
Aviation/Marine...99

Re: February 2020

Posted: Sat Feb 15, 2020 11:06 am
by jasons2k
Cpv17 wrote:
Fri Feb 14, 2020 9:00 am
I would take a repeat of this in a heartbeat. Unfortunately for me, that’ll never happen here again.
Careful what you wish for. The novelty wears off after awhile. I lived through the '93 Superstorm - was in Birmingham, Alabama at the time. The event itself was very exciting for a weather geek like me. Talk about an adrenaline rush seeing and hearing Thundersnow at night and 16" of snow getting dumped on you. The first day after was pretty amazing - playing in the snow and just taking-in the whole experience. I took a lot of great pictures and jumped in the snow like a little kid.

But...longleaf pine trees can't handle that much snow. A lot of them snapped. The recovery was similar to what we experienced after Ike. No power, phone or cable for two weeks. No power meant the electric furnace wouldn't run. The house got frigid. We slept in front of the fireplace in sleeping bags for 3-4 nights until it warmed-up again. Stores were closed for days, and what supplies they had quickly ran out. Thousands of people were trapped on the freeways and had to be rescued with Humvees and the National Guard.

Was it cool? Was it fun and exciting? Yeah, for the days leading up to it, during, and for about a day after the storm hit. After that, the snow melted and it was two weeks of hell.

Re: February 2020

Posted: Sun Feb 16, 2020 10:29 am
by Ptarmigan
The Valentines Day snow Of 1895 is a very rare event. It probably happens every 200 to 500 years. It occurred in a major cold blast.

Re: February 2020

Posted: Mon Feb 17, 2020 12:07 am
by DoctorMu
NOAA: hottest January evah (in recorded weather history).

Mosquito hawks appeared today in BCS weeks (too) early.

As a North Carolinian I can say it's ice that snaps branches and kills pine trees, not so much snow.

Re: February 2020

Posted: Mon Feb 17, 2020 7:11 am
by jasons2k
Not a drop overnight. Last several systems have underperformed. Hopefully this isn’t a trend going into the spring storm season.

Re: February 2020

Posted: Mon Feb 17, 2020 7:23 am
by jasons2k
DoctorMu wrote:
Mon Feb 17, 2020 12:07 am
NOAA: hottest January evah (in recorded weather history).

Mosquito hawks appeared today in BCS weeks (too) early.

As a North Carolinian I can say it's ice that snaps branches and kills pine trees, not so much snow.
I suppose it depends on the location and species. Loblolly and southern longleaf pines are confined to eastern North Carolina. The pines in western North Carolina are better adapted to snow. At higher elevations you get into fir tree conifers, which can handle the snow just fine.

Birmingham is just far enough south to have more of the longleaf variety of pines. You can pull-up a map of Alabama on Google Earth or satellite view, and you can see the terrain in northern Alabama, north of Birmingham, the color of the vegetation transitions to a deeper green, especially on the ridges. This is because those pines are shortleaf pines and have a slightly darker, more blue-ish or olive color versus the bright green of southern pines.

Yes, ice is a major problem for pine trees. But during the storm, we heard lots of pines snapping during the night because of the weight of the heavy snow. It was eerie. The ice wasn’t really a problem until after the first day when the snow re-froze into ice. By then, the damage was already done.

Re: February 2020

Posted: Mon Feb 17, 2020 1:04 pm
by DoctorMu
Cpv17 wrote:
Fri Feb 14, 2020 9:00 am
I would take a repeat of this in a heartbeat. Unfortunately for me, that’ll never happen here again.
Amazing. The snow miracle of Christmas Eve 2004 has to be Top 3-5.