Area Forecast Discussion
Issued by NWS Houston/Galveston, TX

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FXUS64 KHGX 291735

Area Forecast Discussion
National Weather Service Houston/Galveston TX
1235 PM CDT FRI JUL 29 2016

Daytime heating should again trigger some showers and
thunderstorms this aftn. Convection should wane between 22-00z.
Some residual cirrus will linger through the evening before skies
clear. Fcst soundings support MVFR cigs over northern TAF sites
between 09-13z. Winds will become light and possibly SW by
morning. Models coming in a bit drier on Saturday and will not
mention precip for now but may add a VCSH at 21z update pending
the 12z ECMWF. 43



A much drier start to the day than the past few days across
Southeast Texas, but have started to see a few showers begin to
pop up along the coast as temperatures have risen into the mid to
upper 80s. This trend is expected to continue through the
remainder of the afternoon as additional heating occurs.
HRRR/RAP/ARW guidance shows greatest coverage along and south of
Interstate 10 today where deeper moisture resides (the morning
Corpus Christi sounding reporting precipitable water values around
2 inches compared to Fort Worth`s reporting 1.57 inches). Given
trends in storm coverage over the past few days under similar
environmental conditions, have raised pops for the southern half
of the region. Forecast soundings continue to indicate the
presence of a dry subcloud layer during the afternoon and cannot
rule out an isolated wind gust (20-30 MPH) with stronger cells.

Also seeing a few isolated showers develop across Central Texas
into the Piney Woods region, where SPC mesoanalysis shows some
weak warm air advection around 850 MB. Expect these showers to
remain elevated and relegated largely to the morning hours as 850
MB flow backs by early afternoon. Otherwise, only made minor
updates to hourly temperatures and dew points based on
observations with afternoon temperatures expected to rise into the
low to mid 90s today.



As has been the case the last few mornings, widely scattered
showers continue to develop over the Upper Texas Coastal waters of
the Gulf of Mexico. A few of these showers are moving inland but
weaken rapidly. Upper air analysis at 500mb for 00Z shows upper
level ridge over the Desert SW with another ridge over the W
Atlantic off the coast of the Carolinas. In between the two ridges
is a weakness with slight troughing from the Great Lakes towards
the Texas Gulf Coast. This pattern supports mainly NW flow aloft
through the Plains with a couple of short waves moving across the
Plains and Midwest. Water vapor imagery shows a TUTT over the
western Gulf which will provide at least some ascent today as it
moves towards the Rio Grande and Mexico coast. The CRP/LCh 00Z
soundings show about 2 inches of precipitable water and expect
this moisture to remain over the area today. Forecast will keep 20
PoPs this morning with an increase to 30/40 PoPs along the coast
as lift from the sea breeze supports more scattered shower and
thunderstorm activity during peak heating. A few of the stronger
storms could produce some gusty winds and brief heavy rainfall
like the last few days.

Synoptic models are in pretty good agreement with the evolution of
the upper level pattern for the next 7 days. The troughing over
the Great Lakes into Texas flattens through the weekend and the
upper level ridge near Carolinas retrogrades more over the N Gulf
Coast by Monday. Precipitable water trends through the weekend
range from 1.8 to 2 inches but then decrease below 1.8 inches
going into the work week. Forecast will keep 20 to 40 PoPs for the
weekend but expect a dry forecast going into the work week.

Upper level ridge builds over much of the Plains through the
middle of next week supporting a few rain free days and max temps
reaching the mid/upper 90s. Heat index values will push above the
105F mark in a few areas for early next week but this will be
typical for the end of July or beginning of August. The ridge
seems to weaken a bit next Thursday/Friday as a weak upper low or
TUTT forms over the NW Gulf during this time. Precipitable water
values also increase to above 1.8 inches during this time. This
will support the return of rain chances for the end of next week.



College Station (CLL)      96  76  97  77  97 /  20  10  10  10  10
Houston (IAH)              95  77  96  77  96 /  40  10  30  10  30
Galveston (GLS)            92  82  92  82  92 /  20  10  30  10  20




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