Forecast Discussions mentioning any of
"ACARS" "MDCRS" "AIRCRAFT" "TAMDAR" "AMDAR" "WVSS" received at GSD on 03/31/19
Area Forecast Discussion
National Weather Service Houston/Galveston TX
938 PM CDT Sat Mar 30 2019
.UPDATE...
At the top of the 9 PM hour, the cold frontal boundary is located
roughly across our far offshore waters with Buoy 42019`s strong
winds veering north at 25 to 30 mph. Early Sunday morning weak
PVA from a shortwave jet-level disturbance moving east over the
coastal waters will overrun the offshore frontal boundary and keep
the chance for maritime showers alive through tomorrow. The
combination of jet stream positioning, weak westerly disturbances
and the remnants of today`s frontal boundary will keep coastal
county and Gulf shower chances relatively high through early next
week or early April. Cold air advection with continued overcast
will create sluggish warming into the upper 50s to near 60 F by
late day...early morning cooling into the mid to upper 40s
(tomorrow) / upper 30s to lower 40s Monday and Tuesday morning.
Factors such as weak upper level troughing over the state, a
Central Texas jet nosing into eastern Texas along with a somewhat
weak isentropic upglide pattern will keep cool, cloudy and
occasionally wet going into the month of April. 31
&&
.PREV DISCUSSION... /ISSUED 620 PM CDT Sat Mar 30 2019/
AVIATION...
Cold front should be pushing off the coast within the hour.
Ceilings are falling to between 800-1500 feet for a few hours
post fropa then start lifting as depth of cooler air deepens.
North winds should remain gusty overnight with gusts in the
20-30kt range inland...and eventually 30-40kt along the immediate
coast and offshore. A thin band of precip along the boundary will
edge offshore early this evening, but another disturbance will be
heading up from the southwest...likely initiating another round
of rainfall...perhaps more widespread for terminals south of I-10
in the 5-11z timeframe. VFR and breezy conditions should persist
Sunday morning onward. 47
&&
PREV DISCUSSION... /ISSUED 348 PM CDT Sat Mar 30 2019/
A cold front has nearly pushed through to the Gulf of Mexico -
until it does later this afternoon, showers and perhaps even a
lightning strike or two may be seen near the coast. Afterwards,
things turn much breezier and colder. Though the winds should
slowly die down Sunday, colder temps will persist until the middle
week. The first half of the week will also see lingering chances
of showers despite the influx of colder, drier air. From that
point, look for things to warm back up, with highs reaching into
the 80s for most by the end of the work week. While chances for
showers may crop up here and there, the next substantial chance
for rain and storms will come this weekend along another frontal
passage.
NEAR TERM [Through Tonight]...
As of 330 pm CDT, the cold front looks to have passed the bulk of
the Sam Houston National Forest, Conroe, NW Harris County, and
Eagle Lake. It had not yet reached the urban core of Houston,
Sugar Land, Wharton, or Cleveland. Temperatures are dropping
pretty rapidly behind the front, with Crockett at 54 and Bryan at
57, while coastal sites remain a good 20 degrees warmer in the mid
to upper 70s.
Showers will continue in the remaining portion of the area ahead
of the front until that front passes. Satellite and AMDAR
soundings have shown the cap has held tight most of the day, and
I expect that to continue, but I can`t totally rule out a strike
or two of lightning - and so while I`ll trim up lightning
potential even more from this morning, I won`t completely erase it
along the front.
Beyond that, the story of the night will be the dropping temps on
gusty north winds. Though I don`t expect anyone to fall below 40
degrees tonight, lows still look to be a good ten degrees below
seasonal averages. Winds will add to the bite of this air, with
northerly gusts reaching to around or above 20 mph through the
night. Because of the long fetches down the bays with post-frontal
winds, a wind advisory is out for the barrier zones tonight
through mid-morning tomorrow.
While most should dry out and see the clouds being to scatter
overnight, some lingering chances for light showers may persist
right on the coast into tomorrow.
SHORT TERM [Sunday Through Monday Night]...
Chilly weather persists into the early part of the week. Indeed,
Sunday and Monday nights are likely to be the coldest of the week,
with spots like Caldwell, Bryan/College Station, and Crockett
managing to fall into the upper 30s Sunday night, then middle 30s
Monday night. Sub-40 temps may be seen as far south as Conroe and
in the rural areas to the west of Houston.
A couple shortwaves on Sunday and Monday will also keep continuing
low chances for rain - restricted to the coast Sunday, a little
more widespread Monday. Still, moisture is not particularly
impressive, and with a solid dry layer at the surface, squeezing
much of anything out of this setup will be tough. While not in the
forecast, if we could manage some elevated convection, I could see
us repeating the earlier feat of seeing a few tiny hail stones in
the absence of rain. Seems very unlikely at this point, but
there`s at least a plausible avenue for it to happen.
LONG TERM [Tuesday Through Saturday]...
A surface high looks to drift into, and then through the region
from the middle of the week onward. Meanwhile, aloft, mid-level
ridging sets up. This primes us for a solid warmup, with highs in
the 70s by Wednesday, and widespread highs in the 80s by Friday.
Developing onshore flow will assist in speeding the warmup along,
but may also set up enough isentropic lift and moisture return
that the chance for showers will sporadically show up late in the
week, as well.
Next weekend will likely bring another cold front and our next
substantial shot at rain and storms. However, with precious little
agreement on much of anything in the guidance, I`m mostly just
going with a blend and a forecast of least regret. Trying to
position myself for an easy shift to whatever scenario takes
primary focus in the coming days.
MARINE...
Small craft advisories in effect tonight with northerly winds 20-
25kts gusts 30-35kt. Seas this afternoon 2-4 feet will quickly
build this evening to 4-6 nearshore and 8-11 offshore. Could see
some more concentrated development of showers and thunderstorms
over the far coastal waters where capping tapers off and
instability remains tonight. A s/w passing over late evening/early
Sun morning could also help to refire the development of showers
post frontal. SCA starting sooner for the winds occuring behind
the front and in effect until 2 pm Sunday. Low tide tonight/early
Sunday will probably bring some stronger outbound currents and
lower water but not getting down into low water advisory issues.
High pressure over TX maintains north and northeasterly flow over
the Upper TX coastal waters through Tuesday morning then winds
become more easterly/southeasterly as high slides off to the east.
Rain chances returning late Wednesday as moist axis is aimed at the
Matagorda bay region with increasing strength to the southeasterly
flow. SCA/SCEC a good bet by Wednesday night/Thursday morning.
45
&&
.PRELIMINARY POINT TEMPS/POPS...
College Station (CLL) 73 44 56 38 57 / 30 10 10 10 40
Houston (IAH) 78 48 58 42 61 / 40 10 10 10 30
Galveston (GLS) 75 51 58 49 60 / 60 50 30 10 30
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...Wind Advisory until 10 AM CDT Sunday for the following zones:
Brazoria Islands...Galveston Island and Bolivar Peninsula...
Matagorda Islands.
GM...Small Craft Advisory until 2 PM CDT Sunday 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...Galveston Bay...Matagorda Bay...
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...31/47