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Area forecast discussion 
National Weather Service Houston/Galveston Texas
400 am CDT sun Apr 26 2015

Discussion...
fog has developed over most of southeast Texas early this morning and
conditions look favorable for the fog to persist through the early
morning hours. Will watch trends and a dense fog advisory may yet
be required but only only kbyy meets the criteria of 1/4sm. Flow
aloft remains out of the SW and both the GFS and NAM show a weak
upper level disturbance this afternoon along with an increase in precipitable water
values. Forecast soundings show very dry air in the 850-700 layer
still feel the weak disturbance could generate a few rain showers/thunderstorms and rain so
will maintain the 20 probability of precipitation today.

An upper level low over Arizona will move east and approach the Texas
Panhandle tonight. Precipitable water values begin to increase and should 1.7-1.9
inches by Monday 12z. Southeast Texas will lie in a weak couplet between
12z-18z Monday. The best dynamics appear to be Monday morning if the
GFS/European model (ecmwf) are to be believed. The Canadian...nam12...Texas tech
WRF and arw/nmm all target the area in the afternoon primarily
because they are a bit slower with the upper level trough. Not
exactly confident with regard to the timing on Monday so will
broad brush likely probability of precipitation and wait for the models to resolve timing
differences. Forecast soundings are in very good agreement that there
will be some type of severe weather with the storms when they
develop. Cape values are between 3000-4000...Li values are -10...
sweat index is over 400 and there looks like there will be plenty
of shear. Will add severe wording to the northern zones for
tonight after 06z. Storm Prediction Center has outlooked the northwest third of southeast Texas
in slight risk overnight and all of southeast Texas in slight risk on
Monday. There is also some potential for heavy rain on Monday
depending on where storms develop and how much training of storms
occurs. Wpc has outlooked the eastern half of the area in
excessive rainfall for Monday.

A cold front will cross southeast Texas late Monday night with breezy northwest
winds developing in the wake of the front. Wrap around cloud
cover...brisk north-northwest winds and cold air advection will prevail on
Tuesday. The upper trough will still be close and this feature
will probably generate a few showers over mainly the NE part of
the area. Skies begin to clear Tuesday night and generally clear to
pt cloudy skies will prevail through Friday. The upper trough
moves east on Wednesday but a piece of of the upper trough retrogrades
into southeast Texas on Thursday. It looks too dry to generate precipitation but
500 heights lower to 567 dm so Thursday will remain unseasonably cool.
Moisture returns next weekend along with a warm up. A weak short
wave coupled with the deeper moisture will produce a few showers
by next Sunday. 43

&&

Marine...
onshore winds will persist through Monday. On Monday another round
of thunderstorms are expected with isolated strong storms possible. A
cold front will then move off the coast Monday night or early
Tuesday morning. A consensus of the models generates advisory
criteria wind speeds Tuesday into Wednesday morning...with
diminishing winds on Wednesday. High pressure will then move into
the Gulf waters by Friday.

40

&&

Preliminary point temps/pops...
College Station (cll) 88 69 81 59 69 / 20 50 60 40 20
Houston (iah) 88 72 82 64 72 / 20 30 60 50 20
Galveston (gls) 78 74 78 69 73 / 20 20 60 40 10

&&

Hgx watches/warnings/advisories...
Texas...none.
GM...none.
&&

$$

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