September 2020:

General Weather Discussions and Analysis
User avatar
jasons2k
Posts: 3140
Joined: Thu Feb 04, 2010 12:54 pm
Location: Imperial Oaks
Contact:

Re: September 2020

Post by jasons2k » Mon Sep 14, 2020 10:19 am

000
WTNT64 KNHC 141602
TCUAT4

Hurricane Sally Tropical Cyclone Update
NWS National Hurricane Center Miami FL AL192020
1100 AM CDT Mon Sep 14 2020

...NOAA HURRICANE HUNTERS FIND THAT SALLY HAS RAPIDLY STRENGTHENED
TO A HURRICANE...

Data from a NOAA Hurricane Hunter aircraft investigating Sally
indicate the system has rapidly strengthened to a hurricane,
with maximum sustained winds of around 85 mph (140 km/h) with higher
gusts. The estimated minimum central pressure is 985 mb (29.09
inches).

A Special Advisory will be issued shortly to update the intensity
forecast for Sally.


SUMMARY OF 1100 AM CDT...1600 UTC...INFORMATION
-----------------------------------------------
LOCATION...28.6N 86.9W
ABOUT 135 MI...220 KM ESE OF THE MOUTH OF THE MISSISSIPPI RIVER
ABOUT 175 MI...280 KM SE OF BILOXI MISSISSIPPI
MAXIMUM SUSTAINED WINDS...85 MPH...140 KM/H
PRESENT MOVEMENT...WNW OR 285 DEGREES AT 6 MPH...9 KM/H
MINIMUM CENTRAL PRESSURE...985 MB...29.09 INCHES

$$
Forecaster Brown/Brennan

Cromagnum
Posts: 1018
Joined: Thu Feb 03, 2011 10:42 pm
Contact:

Re: September 2020

Post by Cromagnum » Mon Sep 14, 2020 11:46 am

Dang. Mississippi is gonna get thumped pretty bad. Coming shore as a 90-100 mph cane and hanging around for 2-3 days.

User avatar
DoctorMu
Posts: 2324
Joined: Sun Jun 28, 2015 10:58 am
Location: College Station
Contact:

Re: September 2020

Post by DoctorMu » Mon Sep 14, 2020 12:24 pm

Cromagnum wrote:
Mon Sep 14, 2020 11:46 am
Dang. Mississippi is gonna get thumped pretty bad. Coming shore as a 90-100 mph cane and hanging around for 2-3 days.
St. Bernard Parish and Biloxi are going to feel some pain. Mobile could get dumped on as Sally is a very right handed storm.

User avatar
tireman4
Global Moderator
Global Moderator
Posts: 2857
Joined: Wed Feb 03, 2010 9:24 pm
Location: Humble, Texas
Contact:

Re: September 2020

Post by tireman4 » Mon Sep 14, 2020 3:18 pm

000
FXUS64 KHGX 142030
AFDHGX

Area Forecast Discussion
National Weather Service Houston/Galveston TX
330 PM CDT Mon Sep 14 2020

.SHORT TERM [Through Wednesday Night]...

A bit drier for the next couple of days as the disturbance to the
south moves further away to the south. To our east, Hurricane Sally
hugs the norther gulf coast and is expected to make landfall late
Tuesday. Being between the disturbance and hurricane we dont see too
much for active weather. For the rest of today, some showers and
thunderstorms are forming in the western counties, which will begin
to dissipate shortly after sunset. Most of the convection should stay
west, if not far west, of I-45. Tomorrow`s pattern will be similar
with the air mass storms forming in the western counties and moving
southwest. Wednesday evening we see higher rain chances as Hurricane
Sally is weakening after making landfall. Rain bands will become more
broad, and is expected to have some of these waves of showers move
into the area.

With no change in air mass, high and low temperatures remain
about the same. Highs average in the low to mid 90s, and lows in the
mid to upper 70s. Winds will stay northerly to northeasterly at
around 10mph in the day with lighter winds at night. Humidity does
decrease a bit, but probably not too noticeable with only about a 5%
decrease in the RH. Long term is looking a bit more promising to
start seeing some relief from the heat! 35

.LONG TERM [Thursday Through Monday]...

A robust short wave will will be oriented from NE to SW across the
state. Initially, thoughts were that the s/wv would be strong enough
to generate widespread showers and thunderstorms Thu/Fri but
lackluster jet dynamics and a wedge of drier air filtering into the
are from the NE have reduced confidence in widespread precipitation.
Looks like the best rain chances Thu/Fri will be over the SW zones
and toward the coast as a weak upper low forms over South Texas and
drier air continues to move into the area from the NE on Friday.
Fcst soundings show convective temperatures between 85-88 degrees
both days so diurnally driven shra/tsra should still be possible
both days.

High pressure over the northern Great lakes on Friday night will
ridge into the area and drier air will gently ooze into the region
from the north. A weak coastal trough will also try to develop off
the Middle and Deep South Texas coast. At this time, it looks like
the drier air will dominate on Saturday but by Sunday a well defined
coastal trough will begin to focus moisture along the coast. East
winds over the Gulf will converge with N-NE winds over land and this
boundary will serve as a focus for shra/tsra Sun Nite and Monday.
Highest rain chances will again focus near the coast and offshore.
Some model differences noted in the long term as the Canadian and
ICON hold the dry air in place while the GFS is very aggressive with
the moisture return and PW values reach 2.35 inches. Will lean
toward the conservative NBM for PoPs. 43

&&

.AVIATION [21Z TAF Update]...

MVFR ceilings to the north stuck around a lot longer than
anticipated. With that, expect ceilings tomorrow to do roughly the
same. 35

.AVIATION [18Z TAF Issuance]...

MVFR and IFR ceilings are scattering out and lifting at most of the
TAF sites. Within a couple of hours, VFR conditions will prevail.
While most of the higher 2.0+ PWATS are going to be in the western
TAF sites, chances for airmass storms are still possible for all
locations except GLS at this time. The biggest threat will be CLL
and SGR this afternoon but the orientation of the moisture axis
could shift slightly and provide the needed moisture to trigger the
convection at UTS/CXO/IAH/HOU. As the airmass storms dissipate shortly
after sunset, VFR conditions will remain for the night. Tomorrow
morning, MVFR to IFR ceilings are expected to return to the TAF
sites. Norther flying areas could see CIGs below 1000ft and
IAH/SGR/HOU/LBX at around 1500ft. Timing to dissipate tomorrow looks
to be about the same as today; close to 18z. 35

&&

.MARINE...

The main story will be increasing seas and large swells today into
Tuesday as Hurricane Sally moves into the LA and MS border. Early
this afternoon, surface observations from buoys reported winds
around 15 to 20 knots with seas from 3 to 5 feet. This trend will
continue tonight into Tuesday, with the greatest impact over the
offshore waters. A Small Craft Should Exercise Caution headline is
in effect for the entire marine zones.

Light northwest to northeast flow is expected Tuesday afternoon into
late Wednesday with seas from 1 to 3 feet. Gusty surface winds and
increasing seas return Friday into the weekend as a surface front
slides southward into our region. The passage of this frontal
boundary could bring northeast winds from 15 to 20 knots at times
and seas up to 5 feet. Caution flags or advisories may be required.

Precipitation-wise, different troughs will move through the region,
producing isolated to scattered showers and thunderstorms each
night. The best chance for thunderstorms will be Thursday and Friday
and then again on Sunday as another trough moves in. 05

&&

.TROPICAL...

The tropics remain quite active as we remain near the peak of an
abnormally active season as a whole. The main concern across the
Gulf continues to be TS Sally, which is expected to strengthen to
hurricane status before making landfall near the MS/LA border
tomorrow. Aside from increasing seas due to the system`s swells,
SE Texas is not expected to receive any direct impacts.

Elsewhere, the NHC continues to monitor Hurricane Paulette, TD
Renee, TD Twenty, and two tropical waves near the Cape Verde
Islands. At this time, current forecast guidance suggests that
none of these systems will pose a direct impact to SE Texas. The
most up-to-date forecast information can be found at
www.hurricanes.gov.

Cady

&&

.PRELIMINARY POINT TEMPS/POPS...

College Station (CLL) 73 90 72 91 72 / 10 20 0 30 20
Houston (IAH) 77 95 76 94 76 / 10 20 0 30 20
Galveston (GLS) 81 93 81 92 80 / 20 20 20 20 30

&&

.HGX WATCHES/WARNINGS/ADVISORIES...

TX...None.
GM...SMALL CRAFT SHOULD EXERCISE CAUTION until 7 PM CDT 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.


&&

$$

SHORT TERM...35
LONG TERM...43
AVIATION...35
MARINE...05
TROPICAL...Cady

Stormlover2020
Posts: 173
Joined: Mon Jun 01, 2020 5:04 pm
Contact:

Re: September 2020

Post by Stormlover2020 » Mon Sep 14, 2020 3:45 pm

Need to watch the boc for development

Cpv17
Posts: 1442
Joined: Fri Aug 31, 2018 12:58 pm
Location: El Campo/Wharton
Contact:

Re: September 2020

Post by Cpv17 » Mon Sep 14, 2020 4:37 pm

Stormlover2020 wrote:
Mon Sep 14, 2020 3:45 pm
Need to watch the boc for development
I agree. The Euro looks interesting.

User avatar
Rip76
Posts: 1411
Joined: Mon Feb 15, 2010 12:38 am
Location: Friendswood
Contact:

Re: September 2020

Post by Rip76 » Mon Sep 14, 2020 5:35 pm

Stormlover2020 wrote:
Mon Sep 14, 2020 3:45 pm
Need to watch the boc for development
What timeframe?

User avatar
tireman4
Global Moderator
Global Moderator
Posts: 2857
Joined: Wed Feb 03, 2010 9:24 pm
Location: Humble, Texas
Contact:

Re: September 2020

Post by tireman4 » Mon Sep 14, 2020 5:46 pm

I saw that too. Always keep a wary eye to the sky...

1. A broad area of low pressure over the southwestern Gulf of Mexico is
currently producing little shower or thunderstorm activity. Any
development of this system should be slow to occur while the low
meanders over the southern Gulf of Mexico for the next several days.
* Formation chance through 48 hours...low...10 percent.
* Formation chance through 5 days...low...20 percent.

User avatar
Rip76
Posts: 1411
Joined: Mon Feb 15, 2010 12:38 am
Location: Friendswood
Contact:

Re: September 2020

Post by Rip76 » Mon Sep 14, 2020 5:52 pm

Oh yes I saw the blowup down there, but I thought that was moving South.

Cpv17
Posts: 1442
Joined: Fri Aug 31, 2018 12:58 pm
Location: El Campo/Wharton
Contact:

Re: September 2020

Post by Cpv17 » Mon Sep 14, 2020 6:23 pm

Rip76 wrote:
Mon Sep 14, 2020 5:52 pm
Oh yes I saw the blowup down there, but I thought that was moving South.
Yeah, but it’s expected to move back north early part of next week. I might add too that the BOC has been untouched too so you could definitely see something explode down there rather easily given the right setup and basically the whole basin has a favorable setup right now it seems. Everything is exploding. Reminds me of 2005.

Post Reply