Area Forecast Discussion
Issued by NWS Houston/Galveston, TX

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

000
FXUS64 KHGX 161800
AFDHGX

Area Forecast Discussion
National Weather Service Houston/Galveston TX
1200 PM CST Tue Jan 16 2018


.DISCUSSION...
Numerous reports of freezing rain/sleet/snow across the area. Even
Galveston getting into the game with 3 hours of snow in the
observation. Expanded the Winter Storm Warning to the coast.
Guidance showing abundant lift spreading over the area this
afternoon with depth of cold air increasing. Precip should
transition over to mainly snow by mid afternoon. Unfortunately the
temperatures down to 25 to 29 in the Houston Metroplex-23 to 26
north. Expect that in the next couple of hours icing should
transition from elevated roadways to surface streets in the
Houston Metro.



&&

.AVIATION...
Light freezing rain tapering off with snow and sleet taking over.
Ceilings MVFR IAH southward and 3500-6000ft to the north of IAH.
As drier air wedges in this should speed the transition to snow
and lift ceilings. S/W moving toward NCTX should give a burst of
snow to the region 19-22z with a corresponding lowering of VISBY.
Light snow will probably linger at HOU southward 22-02z. VFR
conditions should prevail at all sites by 03-06z. Temperatures
rising back above freezing 18-19z timeframe Wednesday.

45

&&

.PREV DISCUSSION... /ISSUED 413 AM CST Tue Jan 16 2018/

DISCUSSION...
Arctic cold front is now moving through the coastal waters. Behind the
front, temperatures have been falling with below freezing readings
now across much of our northern counties and likely creating hazardous
driving conditions where mixed precipitation is falling and any accumulations
are occuring. Breezy and gusty north winds behind the front are helping
to drop wind chill readings to around 20 at some spots at 3 AM, and
expect these values to continue to fall throughout the day with teens
areawide before sunset. South of the current mixed precipitation locations
and possibly all the way to the coast, areas of rain will transition
over to mixed precipitation as temperatures fall below freezing. Some
enhancement during the day could possibly bring pockets of increasing
mixed precipitation coverage resulting in an increasing travel hazard
where any accumulations develop. The Winter Storm Warning and Winter
Weather Advisory will remain in effect with this package, and will
cover the elevated winds and falling wind chills with the statement.
Precipitation will come to an end from north to south beginning this
afternoon and continuing to the coast tonight as strong high pressure
helps to bring much drier air into the area. Future shifts will likely
be able to adjust/remove parts of our area from the Warning and Advisory,
and we will likely be replacing them with Hard Freeze Warnings (Wednesday
morning`s lows in the teens north and 20s south all the way to the
coast) and Wind Chill Advisories (ranging from 5 up north to the teens
at the coast) for much of the area. Wednesday`s record low temperatures
are 0 degrees set in 1930 for CLL, 15 degrees set in 1930 for the City
of Houston, 23 degrees set in 1965 for HOU and 23 degrees set in 1885
at GLS). Temperatures will struggle to warm on Wednesday and should
peak in the mid to upper 30s, but winds will be much weaker. Thursday
morning`s lows will be cold again, ranging from around 20 north to
close to freezing at the coast, and another Hard Freeze Warning will
probably be needed generally to the north of I-10. Look for a warmup
to begin on Thursday, and we might even see some highs in the 70s over
the weekend. As for our next best chance of rain (temperatures will
not be cold enough for anything frozen), it should come around Friday
and Friday night (higher chances near the coast and lower chances inland)
as a mid/upper level storm system move eastward across South Texas,
and then again on Sunday with the approach and passage of the next
cold front. 42

MARINE...
Will maintain current Gale Warning and Advisory flags, but have made
starting time to the current time as the front is now pushing off
the coast. Will also hoist a Low Water Advisory for the bays
(primarily for the northern parts) as strong NNW winds transport
water out. Observed levels are forecast to be around -1.5 MLLW
the mid morning low tide. There could be some frozen precipitation
behind the front before clearing this evening.

High pressure will move east of the region allowing onshore winds to
resume by Thursday night and persist into the weekend. The next
front should move into the area late Sunday. 47

AVIATION...
Transition of precip from liquid to frozen has occurred as far south
as CXO. Temps will continue to fall further in the metro area and
coast thru the day so expect frozen precip there as well. Most of
the precipitation will end by 01z. Strong north winds will develop
in the wake of the front and will begin to subside toward Tuesday
evening. Generally IFR ceilings are expected behind the front
gradually lifting to MVFR this morning with some VFR conditions
developing by late afternoon over the northern TAF sites and after
00z over the south. Skies are expected to become VFR areawide
between 06-09z. 47

&&

.PRELIMINARY POINT TEMPS/POPS...
College Station (CLL)      27  17  37  22  43 /  50  10   0  10  10
Houston (IAH)              32  20  37  25  43 /  80  10   0  10  10
Galveston (GLS)            39  26  37  32  47 /  80  30  10  10  10

&&

.HGX WATCHES/WARNINGS/ADVISORIES...
TX...Winter Storm Warning until midnight CST tonight for the
     following zones: Austin...Brazoria...Brazos...Burleson...
     Chambers...Colorado...Fort Bend...Galveston...Grimes...
     Harris...Houston...Jackson...Liberty...Madison...
     Matagorda...Montgomery...Polk...San Jacinto...Trinity...
     Walker...Waller...Washington...Wharton.

GM...Low Water Advisory from midnight tonight to 6 PM CST Wednesday
     for the following zones: Galveston Bay...Matagorda Bay.

     Small Craft Advisory until midnight CST tonight for the
     following zones: Galveston Bay...Matagorda Bay.

     Gale Warning until midnight CST tonight for the following zones:
     Coastal waters from Freeport to the Matagorda Ship Channel
     out 20 NM...Coastal waters from High Island to Freeport out
     20 NM...Waters from Freeport to the Matagorda Ship Channel
     from 20 to 60 NM...Waters from High Island to Freeport from
     20 to 60 NM.

&&

$$

Discussion...39
Aviation/Marine...45



USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.