August 2019: Weekend Rain Chances/Tracking The Tropics

General Weather Discussions and Analysis
Scott747
Posts: 746
Joined: Tue Feb 23, 2010 9:56 am
Location: Freeport/Surfside Beach
Contact:

Re: August 2019: The Heat Is On/Mid Week Rain Chances

Post by Scott747 » Tue Aug 13, 2019 5:04 pm

Operational GFS is just a mess now. At least it's somewhat coming inline with what the legacy and euro is showing though much stronger and further e towards Louisiana.

Cpv17
Posts: 569
Joined: Fri Aug 31, 2018 12:58 pm
Location: El Campo/Wharton
Contact:

Re: August 2019: The Heat Is On/Mid Week Rain Chances

Post by Cpv17 » Tue Aug 13, 2019 5:33 pm

The old GFS is awesome this run. Strong wave into Deep South TX and a good part of the state gets a good soaking:

Image

User avatar
Katdaddy
Global Moderator
Global Moderator
Posts: 2080
Joined: Thu Feb 04, 2010 8:18 am
Location: League City, Tx
Contact:

Re: August 2019: The Heat Is On/Mid Week Rain Chances

Post by Katdaddy » Wed Aug 14, 2019 5:03 am

Another day of excessive heat with a Heat Advisory in effect for all of SE TX. However showers and thunderstorms are expected later this afternoon N and NE of Houston which will move into the Houston area this evening. Strong downburst winds will be possible in the stronger storms. The SPC has a marginal risk area from Houston metro eastward into SW LA. Scattered afternoon showers and thunderstorms along will slightly cooler temps can be expected from Thursday through next Tuesday.
Attachments
Screen Shot 2019-08-14 at 5.39.48 AM.png
Screen Shot 2019-08-14 at 5.39.48 AM.png (11.8 KiB) Viewed 444 times

Cromagnum
Posts: 595
Joined: Thu Feb 03, 2011 10:42 pm
Contact:

Re: August 2019: The Heat Is On/Mid Week Rain Chances

Post by Cromagnum » Wed Aug 14, 2019 5:54 am

That map does not give me very much confidence.

User avatar
tireman4
Global Moderator
Global Moderator
Posts: 2390
Joined: Wed Feb 03, 2010 9:24 pm
Location: Humble, Texas
Contact:

Re: August 2019: The Heat Is On/Mid Week Rain Chances

Post by tireman4 » Wed Aug 14, 2019 7:39 am

000
FXUS64 KHGX 141137
AFDHGX

Area Forecast Discussion
National Weather Service Houston/Galveston TX
637 AM CDT Wed Aug 14 2019

.AVIATION...
VFR. Increased chance for afternoon convection impacting the more
eastern/metro terminals this afternoon. A slowing northern Texas
outflow boundary will be entering a very warm, moist and unstable
air mass this afternoon. Lift created by this feature, along with
a vicinity sea breeze wind shift and its own possible subsequent
convective outflow, will prime the background enough to place
PROB30s in from those hubs generally from UTS down into southern
Houston (HOU, SGR). The main threat with any strong late afternoon
into early evening thunderstorm will be downburst winds. Remnants
of any residual outflow within pooled higher moisture over the
coastal counties (GLS) will introduce the mention of overnight
early Thursday showers. 31

&&

.PREV DISCUSSION... /ISSUED 431 AM CDT Wed Aug 14 2019/

SHORT TERM [Today through Thursday]...

Another hot day with upper ridging still maintaining its grip across
the state. A shear zone atop this ridging positioned across northern
state is the impetus to the pre-dawn firing of Red River Valley into
northeastern Texas convection. Outflow from this activity will sag
southward into our heated late morning environment and likely
initiate downstream early to mid afternoon showers and
thunderstorms. Regional convection will focus primarily across our
eastern CWA and propagate parallel to northeasterly mid-layer
steering flow towards metro by late afternoon. Scattered cells
should pass across Houston metro and be over the south to
southwestern forecast area by early this evening. Inverted V
soundings (with higher DCAPE values) indicate that downburst winds
from the strongest storms will be the main storm threat mode this
afternoon. Of course, this is the most logically stab at placement
as the mesoscale will be the ultimate decider but feel that the best
convergence will be along the sea breeze boundary and the
aforementioned northern outflow wind shift. A slightly higher surge
of pwat air moving in from the northwestern Gulf, along with
temperatures warming into the upper 90s before overcast thickens up
and late afternoon precipitation comes through, has maximum Heat
Indices ranging in the 106 to 110 F range. Thus, will let the Heat
Advisory ride for another day.

The picture becomes muddled going into the early Thursday morning
hours as it relates to precipitation chances and location. There
will be remnant outflow boundaries left over from today`s shower and
storm activity that will be laying about in the vicinity of the
coastline and points offshore. Festering early Thursday maritime
showers may work themselves onshore with daytime heating. Slight to
low end chances for developing slow-moving cells across our local
waters and these will transition further inland (over the southern
half of the CWA) through Thursday afternoon. Thicker overcast and
more areal precipitation coverage will regulate afternoon warmth to
the middle 90s. Despite the higher moisture, these relatively lower
afternoon maxTs will keep many max Heat Indices under 108 F thus
likely making today the last in this recent string of consecutive
Heat Advisories. 31

LONG TERM [Thursday Night through Tuesday]...

The surface frontal boundary is expected to move very slowly or
remain stalled along or near the coastal regions of upper Texas
and LA Thursday night into Friday morning. This keeps deep low
level moisture entrapped mainly along the Gulf waters and the
coastal counties during that timeframe. Isolated to scattered
shower and thunderstorm activity is expected to continue across
these areas through Friday morning. In the late morning to
afternoon hours Friday, winds become more southeasterly,
increasing moisture transport inland. Soundings indicate PWAT
values around 2.0 inches both Friday and Saturday afternoon,
however, amounts do vary a bit between models. GFS has the driest
driest solution for Friday while the NAM is wetter and the EC is
in the middle. On Saturday, the return of low level moisture is
shown on the models and are in better agreement. On Friday,
development of convection can extend from the Gulf waters into the
central regions of the local area as heating increases and
combines with shower and sea breeze outflows. On Saturday,
coverage should be a little more widespread as the low level
moisture digs a little more northward.

By the end of the weekend into early next week, models have an
upper level shortwave developing across the Rockies and Northern
Plains, which seems to keep the mid to upper level high pressure
meandering to the west of the local region. Moisture profile is similar
Sunday into Tuesday, with the higher moisture values located
south of I-10 and east of I-45. A summertime pattern looks to set
up with passing showers along the local waters and coastal regions
in the late night to morning hours, followed by showers and
possible thunderstorms developing in the afternoon hours each day.
High temperatures in the upper 90s to low 100s return during this
period as well. 24

MARINE...

A west to southwest wind will back more southerly through the day
with the inland intrusion of the sea breeze boundary. Outflow winds
from inland precipitation may swing late day into evening winds
northerly or variable through early Thursday. This vicinity outflow
introduces a higher probability of scattered showers or isolated
thunderstorms occurring during the overnight hours tonight and
tomorrow morning. Other than slightly more moderate pre-dawn
nearshore winds, expect the only period of double digit (onshore)
winds to occur over the weekend. Average near 2 foot sea heights
will pick up to between 3 to 5 foot wave heights in response this
strengthened weekend onshore fetch. 31

&&

.PRELIMINARY POINT TEMPS/POPS...
College Station (CLL) 100 78 98 77 96 / 30 30 20 10 20
Houston (IAH) 99 79 96 79 93 / 50 40 30 10 30
Galveston (GLS) 93 83 92 83 93 / 40 50 40 30 40

&&

.HGX WATCHES/WARNINGS/ADVISORIES...
TX...Heat Advisory until 7 PM CDT this evening for the following
zones: Austin...Brazoria Islands...Brazos...Burleson...
Chambers...Coastal Brazoria...Coastal Galveston...Coastal
Harris...Coastal Jackson...Coastal Matagorda...Colorado...
Fort Bend...Galveston Island and Bolivar Peninsula...
Grimes...Houston...Inland Brazoria...Inland Galveston...
Inland Harris...Inland Jackson...Inland Matagorda...
Madison...Matagorda Islands...Montgomery...Northern
Liberty...Polk...San Jacinto...Southern Liberty...Trinity...
Walker...Waller...Washington...Wharton.

GM...NONE.
&&

$$

Long...24
Short/Aviation/Marine...31

User avatar
DoctorMu
Posts: 1595
Joined: Sun Jun 28, 2015 10:58 am
Location: College Station
Contact:

Re: August 2019: The Heat Is On/Mid Week Rain Chances

Post by DoctorMu » Wed Aug 14, 2019 10:13 am

Scott747 wrote:
Tue Aug 13, 2019 5:04 pm
Operational GFS is just a mess now. At least it's somewhat coming inline with what the legacy and euro is showing though much stronger and further e towards Louisiana.

It's a wreck. Each run is basically a blind monkey with darts. Legacy is more consistent, correct, and entertaining. Canadian and Euro have been more sensible.

User avatar
tireman4
Global Moderator
Global Moderator
Posts: 2390
Joined: Wed Feb 03, 2010 9:24 pm
Location: Humble, Texas
Contact:

Re: August 2019: The Heat Is On/Mid Week Rain Chances

Post by tireman4 » Wed Aug 14, 2019 10:42 am

000
FXUS64 KHGX 141503
AFDHGX

Area Forecast Discussion
National Weather Service Houston/Galveston TX
1003 AM CDT Wed Aug 14 2019

.UPDATE...
Activity that was developing just ahead of the boundary approaching
from the N/NE looks to be mixing out at this time. As per near-term
models, we`ll be expecting re-development across the central/coast-
al counties later this afternoon as the boundary sags further south
and possibly interacts with the seabreeze. Abundant daytime heating
coupled with increased moisture should be enough to support showers
and thunderstorms through the early evening hours. Just a couple of
minor tweaks to the current grids for the update, mainly to account
for going trends. 41

Cpv17
Posts: 569
Joined: Fri Aug 31, 2018 12:58 pm
Location: El Campo/Wharton
Contact:

Re: August 2019: The Heat Is On/Mid Week Rain Chances

Post by Cpv17 » Wed Aug 14, 2019 11:41 am

DoctorMu wrote:
Wed Aug 14, 2019 10:13 am
Scott747 wrote:
Tue Aug 13, 2019 5:04 pm
Operational GFS is just a mess now. At least it's somewhat coming inline with what the legacy and euro is showing though much stronger and further e towards Louisiana.

It's a wreck. Each run is basically a blind monkey with darts. Legacy is more consistent, correct, and entertaining. Canadian and Euro have been more sensible.
The GFS is wanting to send this into Louisiana and we get left on the dry side again..no thanks. And the CMC isn’t even picking up on it.

User avatar
Texaspirate11
Posts: 998
Joined: Tue Dec 31, 2013 12:24 am
Contact:

Re: August 2019: The Heat Is On/Mid Week Rain Chances

Post by Texaspirate11 » Wed Aug 14, 2019 12:00 pm

GFS always wants to wipe out Texas first - i'm not concerned about this one.
Just because you're disabled, you don't have to be a victim
Be Weather Aware & Prepared!
Barbara Jordan Winner in Media
Disability Integration Consultant

stormlover
Posts: 368
Joined: Wed Dec 04, 2013 10:21 am
Location: Lumberton TX
Contact:

Re: August 2019: The Heat Is On/Mid Week Rain Chances

Post by stormlover » Wed Aug 14, 2019 2:59 pm


Post Reply