Wx Infinity Forums

252
FXUS64 KHGX 271803
AFDHGX

Area Forecast Discussion
National Weather Service Houston/Galveston TX
103 PM CDT Tue Aug 27 2019

.AVIATION...
VFR FEW-BKN decks across the board through the early Wednesday
morning hours. Isolated showers beginning to pop up in the
afternoon heat so anticipate the occasional VCSH. Tempo MVFR
ceilings around sunrise once again. A weak boundary washing out
across the region tomorrow may provide the focus for a higher
areal coverage of Wednesday -TSRA once lower 90 surface
temperatures are achieved. This scenario will create a light and
variable wind field. 31

&&

.PREV DISCUSSION... /ISSUED 1053 AM CDT Tue Aug 27 2019/

DISCUSSION...
850 MB temperatures have cooled slightly from yesterday but
considering the warm start to the day, afternoon temperatures look
to be similar to yesterday. A cumulus field is developing
areawide with some cirrus moving over the top, so cloud cover
might be a bit more prevalent than yesterday. Water vapor imagery
shows a weak upper level low spinning just off the coast.
Temperatures are off to a warm start so will leave the Heat
Advisory as configured with the higher heat index values expected
near the coast.

Two areas of concern with regard to precipitation this afternoon.
The first area of concern is over the north as a weak outflow
boundary trudges into the area. Not sure there will be much in the
way of activity but it certainly bears watch. The second area of
concern will be over Harris, Ft Bend and Galveston counties closer
to the periphery of the upper low over the western Gulf. HiRes
guidance is bullish with PoPs between 21-00z and this is also an
area with strong mid level forcing by both the NAM12 and GFS. Will
be watching this area closely as well. Some capping is noted in
the 85-70 MB layer and temperatures will need to reach 94-95
degrees to initiate convection. Too much uncertainty to go much
higher than 20 PoPs for now. 43

&&

I don't get it. Yesterday was a 50% chance of rain at my house and it didn't do anything. Today was basically 0 % chance and it's pouring.

jasons wrote: ↑Tue Aug 27, 2019 10:18 am

djmike wrote: ↑Tue Aug 27, 2019 5:42 am Question: is Florida wide enough to tear apart any system or is their a chance it could reform in the Ngulf?

That’s not an easy question to answer. It depends on a number of factors, such as - what part of the peninsula will the storm cross? The most southern portion across the Everglades, which is mostly water anyway, or further up, where the Florida Ridge actually has some hills?

Storm motion - obviously the quicker it moves, the less influence the land will have.

Atmospheric environment - might be the biggest factor - is the storm strengthening or weakening as it approaches? Is it a large moist pocket with good outflow channels, or is the atmosphere just marginal?

In short - it depends and every storm is unique. Some storms collapse when they touch land and some storms actually continue to intensify with the ‘brown ocean’ effect and/or great atmospheric conditions.

There is no black or white answer...you just have to closely monitor...

"The Florida Alps?" between Lake City and I-4? They might be 200-300 ft high in altitude. "Sugarloaf Mountain" is 312 ft above sea level and NE of Orlando - that's the highest pt in the state. Plus, the state is potholed with lakes - Florida is like a giant, porous reef. The panhandle is probably hillier than the peninsula. A storm could easily reform on the other side in the GoM. Friction is modest on an E-W track.

Cromagnum wrote: ↑Tue Aug 27, 2019 2:19 pm I don't get it. Yesterday was a 50% chance of rain at my house and it didn't do anything. Today was basically 0 % chance and it's pouring.

It also seems like the day shift is more optimistic/generous with rain chances than the overnight shift.

DoctorMu wrote: ↑Tue Aug 27, 2019 3:11 pm

jasons wrote: ↑Tue Aug 27, 2019 10:18 am

djmike wrote: ↑Tue Aug 27, 2019 5:42 am Question: is Florida wide enough to tear apart any system or is their a chance it could reform in the Ngulf?

That’s not an easy question to answer. It depends on a number of factors, such as - what part of the peninsula will the storm cross? The most southern portion across the Everglades, which is mostly water anyway, or further up, where the Florida Ridge actually has some hills?

Storm motion - obviously the quicker it moves, the less influence the land will have.

Atmospheric environment - might be the biggest factor - is the storm strengthening or weakening as it approaches? Is it a large moist pocket with good outflow channels, or is the atmosphere just marginal?

In short - it depends and every storm is unique. Some storms collapse when they touch land and some storms actually continue to intensify with the ‘brown ocean’ effect and/or great atmospheric conditions.

There is no black or white answer...you just have to closely monitor...

"The Florida Alps?" between Lake City and I-4? They might be 200-300 ft high in altitude. "Sugarloaf Mountain" is 312 ft above sea level and NE of Orlando - that's the highest pt in the state. Plus, the state is potholed with lakes - Florida is like a giant, porous reef. The panhandle is probably hillier than the peninsula. A storm could easily reform on the other side in the GoM. Friction is modest on an E-W track.

It is modest relative to other places, like “Shredderola” especially, but It’s enough to make a difference. For example, a trek from Miami to Naples would weaken less than a trek from Vero Beach to Clearwater, all else being equal.

I am a Florida native

233
FXUS64 KHGX 272045
AFDHGX

Area Forecast Discussion
National Weather Service Houston/Galveston TX
345 PM CDT Tue Aug 27 2019

.NEAR Term...Showers and thunderstorms developed earlier this
afternoon and will likely persist through 00z before quickly
ending with the loss of heating. Rain cooled air/outflows have
allowed temperatures to fall and heat index values are below 105
degrees. In areas away from the rain, sfc dew points have mixed
out and these areas are also below Advisory criteria. Have trimmed
the Heat Advisory back and will only include the immediate coast
and portions of the SW zones in the Advisory. Will end the Heat
Advisory at 7 PM. HiRes guidance did well today but models still
had some trouble getting the location correct. Have broad brushed
chance PoPs over the central zones. 43

.SHORT TERM...
Further north, an outflow boundary over East Texas will sag into
the NE zones and will serve as a focus for shra/tsra tonight and
will carry lowish PoPs in that area tonight. A weak cold front
will move into the area on Wednesday afternoon. Lower 500 mb
heights, slightly cooler 850 temperatures and scattered showers
should allow high temperatures to be a few degrees cooler and a
Heat Advisory is not expected to be needed. The highest heat index
values currently forecast on Wednesday range between 101 and 106
degrees. The weak front will probably sag into the central zones
before stalling but the front in combination with a weakness aloft
will allow the chance for showers and thunderstorms to persist
Wednesday night into Thursday. High temperatures on Wed/Thu will
be strongly dependent on cloud cover and when/if showers develop.

43

&&

.LONG TERM...
The front will hang around Thursday night into early Friday but
the boundary will become less defined. 500 heights remain low and
PW values remain around 2.00 inches so still expecting daytime
heating to trigger showers and storms. Labor Day weekend is
looking a bit better with a drying trend Sat/Sun. An inverted
upper trough will approach from the east Sunday night into Monday
and moisture levels increase once again. Could get some showers as
early as Sunday night but more likely on Mon/Tues as the upper
trough approaches the TX coast. 43

&&

..MARINE...
High pressure over the northern Gulf will maintain tranquil maritime
conditions throughout the remainder of the week. Slight to low end
chances for a passing shower or vicinity thunderstorm. Tomorrow`s
weak northern inland boundary working its way into northeastern
Texas will position backing high pressure over the eastern United
States. The orientation of this high will create a few days of
either light southerly or variable breezes over near 2 foot average
sea heights. A Labor Day weekend easterly fetch will push in a
higher swell and pick up seas by an average foot. 31

&&

.PRELIMINARY POINT TEMPS/POPS...
College Station (CLL) 77 96 77 97 76 / 20 30 30 30 10
Houston (IAH) 79 96 79 95 78 / 30 50 30 40 20
Galveston (GLS) 83 92 84 92 82 / 20 30 20 30 30

&&

.HGX WATCHES/WARNINGS/ADVISORIES...
TX...Heat Advisory until 7 PM CDT this evening for the following
zones: Brazoria Islands...Coastal Brazoria...Coastal
Jackson...Coastal Matagorda...Galveston Island and Bolivar
Peninsula...Inland Jackson...Inland Matagorda...Matagorda
Islands.

High Rip Current Risk until midnight CDT tonight for the
following zones: Galveston Island and Bolivar Peninsula.

GM...NONE.
&&

$$

Dang outflow/sea breeze has a void of no convection from I-10 near Katy arcing over past 290, 45, then past 59, to about the Liberty County line and then the rain resumes.

I sure hope this changes!!

Ahhhh, finally getting a few minutes of soaking rain here in Fulshear. It's been ages since we had more than a few drops. Any approaching storm just kept falling apart right before getting here in the past weeks, so we'd only get a couple of drops.

The outflow has pushed through here now. No cumulus or towering cumulus to my south, either. One of the worst weather months ever!!

Anyone noticing that hook now to to west for Dorian? Once it crosses Florida...may enter the gulf

Kingwood36 wrote: ↑Tue Aug 27, 2019 4:54 pm Anyone noticing that hook now to to west for Dorian? Omcr it crosses Florida...may enter the gulf

Yes, there are indications a Western Atlantic Ridge will build as Dorian enters the Florida area. Something to keep an eye on.

MIMIC-TPW2m seems to be generating huge gaps recently http://tropic.ssec.wisc.edu/real-time/m ... anim=html5

I don't notice it in MIMIC-TPW2 http://tropic.ssec.wisc.edu/real-time/m ... anim=html5

jasons wrote: ↑Tue Aug 27, 2019 3:21 pm

DoctorMu wrote: ↑Tue Aug 27, 2019 3:11 pm

jasons wrote: ↑Tue Aug 27, 2019 10:18 am

That’s not an easy question to answer. It depends on a number of factors, such as - what part of the peninsula will the storm cross? The most southern portion across the Everglades, which is mostly water anyway, or further up, where the Florida Ridge actually has some hills?

Storm motion - obviously the quicker it moves, the less influence the land will have.

Atmospheric environment - might be the biggest factor - is the storm strengthening or weakening as it approaches? Is it a large moist pocket with good outflow channels, or is the atmosphere just marginal?

In short - it depends and every storm is unique. Some storms collapse when they touch land and some storms actually continue to intensify with the ‘brown ocean’ effect and/or great atmospheric conditions.

There is no black or white answer...you just have to closely monitor...

"The Florida Alps?" between Lake City and I-4? They might be 200-300 ft high in altitude. "Sugarloaf Mountain" is 312 ft above sea level and NE of Orlando - that's the highest pt in the state. Plus, the state is potholed with lakes - Florida is like a giant, porous reef. The panhandle is probably hillier than the peninsula. A storm could easily reform on the other side in the GoM. Friction is modest on an E-W track.

It is modest relative to other places, like “Shredderola” especially, but It’s enough to make a difference. For example, a trek from Miami to Naples would weaken less than a trek from Vero Beach to Clearwater, all else being equal.

I am a Florida native

Cuba can put a hurtin' on a cyclone, also.

I lived in Gainesville for awhile. A few of the bigger rises were around Alachua.

A weak cool frontal boundary continues to sag S into our Region. While there is not any 'cooler' air associated with the front, it will provide a focus for showers and storms to develop today into Friday. So we are nearing the end of August and looking forward to cooler weather and shorter days as surely Fall is just around the corner!

They took down HGX radar for scheduled maintenance!! Just when the rain was moving into view — seriously??

167
FXUS64 KHGX 281419
AFDHGX

Area Forecast Discussion
National Weather Service Houston/Galveston TX
919 AM CDT Wed Aug 28 2019

.DISCUSSION...
Convection is currently sagging into ne parts of the area. Look
for outflows, seabreeze and daytime heating to allow for additional
sct activity to develop across the region through the day.
Morning update has been sent. 47

&&

.PRELIMINARY POINT TEMPS/POPS...
College Station (CLL) 94 77 98 76 96 / 30 20 30 10 30
Houston (IAH) 95 79 96 79 94 / 40 30 30 10 40
Galveston (GLS) 92 84 91 84 91 / 20 20 30 20 30

&&

.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.

&&

$$


.AVIATION...
Monitoring progress of SHRA/TSRA complex off to our NE that is showing
some signs of edging/building southward. Have added VCSH at UTS, and
it is possible that VCSH/VCTS might be needed further to the S this
morning. Locations getting good daytime heating will see SHRA/TSRA
development during the day. Expect to see decreasing coverage/intensity
this evening, but cannot rule out more development during the overnight
hours tonight through early Thursday morning with a weak front in
the area. 42
&&

.PREV DISCUSSION... /ISSUED 351 AM CDT Wed Aug 28 2019/

DISCUSSION...

Like much of the month before it, August is going out on a toasty
note. Today looks to again be above seasonal averages, with highs
in the low to mid 90s. Fortunately, we are expecting to see the
peak index fall just shy of advisory thresholds.

At the same time, a weak cold front will sag through Southeast
Texas extremely slowly and dissipate over the next several days.
This front will not bring in any colder air, but will provide a
focus for enhanced coverage of showers and storms this week, with
some modestly drier air behind the boundary as lighter and
variable winds become settled out of the northeast.

Into next week, details of the forecast will be extremely
dependent on the path of TS Dorian. There is a small chance this
involves more direct impact, but more likely it will involve how
the storm influences a trough to its west that is expected to
cross the Gulf this weekend.

SHORT TERM [Through Tonight]...

A lingering front in combination with daytime heating will result
in increasing cloud cover and rain chances across Southeast Texas
today. Activity has the potential to be slow moving which could
result in some locally heavy rainfall. With the clouds and rain
should come slightly lower afternoon high temperatures which will
keep a majority of the area below heat advisory criteria. Daytime
development should gradually weaken/dissipate this evening with
the loss of heating, but the lingering boundary could allow for
some additional shower/thunderstorm formation tonight. 42

LONG TERM [Thursday Through Wednesday]...

We`ll be watching two features carefully for their implications on
the long term portion of our forecast. One of those is the cold
front slowly dropping southwards through East Texas towards our
area. By Thursday morning, looking for that boundary to be
somewhere in the general vicinity of the Houston metro. This will
not be a frontal passage in the traditional sense - the frontal
zone is already pretty diffuse, so there will likely be little
left that`s discernible at the surface, with light and variable
winds instead.

The forecast assumes enough of a discontinuity left that it will
provide a focus to enhance the typical afternoon showers and
storms for Thursday and potentially Friday before it totally
washes out. In its wake, look for northeasterly flow to establish
itself over land, perhaps more easterly over the Gulf depending on
how far the front can push. The drier, continental air is progged
to push precipitable water closer to 1.25 inches, and would
effectively dry things out. The drier air should allow for some
cooler nights - at least up north - but the drier air and sunnier
skies will probably negate that entirely when it comes to
afternoon highs.

Next week, we turn attention to the east. The obvious feature is
Tropical Storm Dorian. And, while it`s technically possible we
could see some direct impact, it seems much more likely that we`ll
be looking more at the interplay between it, Tropical Storm Erin,
and what I think is currently a weak upper trough occupying the
space between the two near the Turks and Caicos. While it`s pretty
hard to identify right now, there`s generally good agreement in
the guidance that it will eject into the Gulf this weekend ahead
of Dorian. Where it goes from there could be pretty important as
far as rain potential towards the middle of next week.

Right now, I`m going to count on the Four Corners upper ridge to
build eastward enough next week, and for this tweener trough to
come in low enough that it will be forced farther south into
Mexico. We may end up fairly dry. But, my confidence on this is
fairly low...if the ridge doesn`t build in as strongly, this
tropical feature may be drawn further north. I`m more confident in
seeing enough shear on the edge of the ridge that the stakes here
are just getting a surge of moisture into Southeast Texas or not.
For now, I`m going to hold with low chance PoPs and a
continuation of the slow warming trend established earlier in the
week. But, stay tuned as subtle changes in the forecast could
change how wet the situation looks to be fairly significantly.

MARINE...

Light to occasionally moderate winds along with low seas and
periods of showers and thunderstorms can be expected. 42

TROPICAL...

Tropical Depression Six has become Tropical Storm Erin, but is
still of zero concern to Southeast Texas.

Tropical Storm Dorian is making its way into the northeast
Caribbean, and will be heading towards Puerto Rico and the Virgin
Islands. The trend in the forecast track from the NHC has been
continuously to the east, which is generally good news for us.
This storm is still so far off and far south enough that it
behooves us well to continue to keep an eye on it, but at this
time there remains no indication that Dorian will have any direct
impact on Southeast Texas weather.

CLIMATE...

With very warm temperatures to begin the day, multiple daily
records were set for warm minimum temperatures. College Station -
with a low of 81 degrees - beat its record of 79 degrees from
1902. Hobby`s low of 80 degrees broke a much more recent record of
79 degrees from 2014. Galveston also set a daily warm minimum
temperature record yesterday, only falling to 85 degrees. The old
record was 84 degrees, set in 1989.

Speaking of Galveston, the routine setting of daily and even all-
time warm minimum temperature records has resulted in a very warm
monthly average. Galveston currently has the 2nd warmest August on
record at 88 degrees, behind the record of 88.5 degrees from
2011. To catch that notoriously hot stretch, we would need an
average temperature of 92 degrees for the next four days. Our
forecast would be for an average of 90 degrees over that span. So,
while the record is...probably...safe, it may be a close call.

&&

.PRELIMINARY POINT TEMPS/POPS...
College Station (CLL) 94 77 98 76 96 / 30 30 30 10 30
Houston (IAH) 95 79 96 79 94 / 50 40 30 10 40
Galveston (GLS) 92 84 91 84 91 / 40 30 30 20 30

&&

.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&

$$

Yikes

Hey gang, let's transition our postings regarding Dorian to the September Topic. I believe that will keep things a bit more tidy as August will end before Dorian poses any real threat to the Mainland of the United States.

The outflow from the storms up north just pushed south/southwest of here. I hope that doesn’t shut down my rain chances. Nauseating...

Edited: yep, sure enough everything to the north is falling apart and the outflow has pushed way south of here now, bisecting Harris County. Unless it lifts back north (not holding my breath) I get shafted once again.

12Z Euro has Dorian crossing Florida into the Gulf and strengthening.