Scientific Forecaster Discussion
Area forecast discussion...updated
National Weather Service Mobile Alabama
929 PM CDT Monday Aug 3 2015
Update...the current forecast is on track and only minor updates were
needed for ongoing trends. Updates have already been sent. /13
00z issuance...VFR conditions will prevail through the
next 24 hours. /13
Previous discussion... /issued 356 PM CDT Monday Aug 3 2015/
Short term /now through Tuesday/...
dry air and vigorous mixing has been the main story across the area
today. Dewpoints in the 60s were common across the entire
area...including the coast...for much of the morning and afternoon.
The dewpoint dipped down to 59 last hour at the Mobile regional
Airport before soaring back up into the low 70s as the sea breeze
marched inland this hour. The sea breeze boundary is pushing further
inland across southern Alabama and southeast Mississippi at this
hour...in comparison to the Florida Panhandle where it still
parallels the I-10 corridor. Drier air will continue to suppress
convection across the northern half of the area today. An isolated
storm across coastal areas and along the sea breeze is still not out
of the question this afternoon and evening...although not looking
As high pressure at the surface continues to nudge its way back
across the Gulf...southwesterly flow will become better established
across the entire area by Tuesday. Moisture will begin to spread
across the area Tuesday afternoon with this onshore flow. This is
evident in modeled precipitable water values which slowly recover
through the short term...near 1.5-1.7 inches Tuesday afternoon
across the southern half of the area. Expecting more coverage in
storms by Tuesday afternoon...in comparison to this afternoon...
predominantly across coastal counties and along the sea breeze. That
being said...keeping probability of precipitation no higher than 20-30 percent along the
Florida Panhandle in the afternoon.
Temperatures tonight will fall into the low 70s across much of the
area...while areas north of the I-84 corridor may even dip into the
upper 60s. Coastal locations will remain near 76-78 overnight. With
the lack of convection across the northern tier of the area on
Tuesday...expecting temperatures to top out around 98-99 with a few
locations breaking the century mark. Despite slightly warmer
dewpoints across the southern portion of the area...heat indices
will only approach 105-106 briefly before the sea breeze progresses
inland. Further inland...heat indices will range from 99-102. 07/mb
Long term /Tuesday night through Monday/...
forecast confidence is on the low side for much of the upcoming long
term forecast period. Ensemble members are (seemingly) all over the
place with the placement and timing of specific features associated
with sensible weather production. The general trend is as follows...
A shortwave trough is expected to top an upper-level ridge axis
Tuesday night...as it heads southeastward toward the Ohio Valley.
Some amplification of the upper ridge over the western United States
will likely be seen...as troughiness in the upper atmosphere
strengthens closer to home. A middle-level southwesterly flow should
develop as this occurs...allowing boundary layer moisture to deepen
across the region beginning about mid-week. Precipitable water
values in excess of 2 inches may be seen through the end of the week
in parts of our area.
The cross-isobaric flow afforded by the shortwave trough should
provide enough momentum to push another cold front (in name only)
southward from the upper Midwest. Right now...it looks like the
front should move into the Tennessee Valley during the day Friday
then slow as it heads toward the ih-20 corridor during the upcoming
By the time the end of next weekend rolls around...it looks like an
impulse in the northern stream will push upper-level troughiness in
our area to the east. This should allow the ridge to reassert
itself in the Sunday/Monday time frame.
In general...we expect a scattered smattering of convection through
the end of the week... with slighly greater odds migrating northward
by evening. Convection should become more isolated by days 6-7. Of
course...though...the devil is in the details.
Increasing boundary layer moisture...combined with the possibility
of heightened rain chances and more cloud cover...should temper
afternoon highs a skosh after mid-week. /02/
winds have turned and strengthened through the afternoon
to a more southwesterly pattern. Surface high pressure will continue
to nudge into the north central Gulf from the southeast...which will
cause the light to moderate southwest to west wind to persist
through the remainder of the week. Winds will be higher each
afternoon across the near shore waters and bays associated with
showers and storms. 07/mb
Preliminary point temps/pops...
Mobile 73 96 76 93 75 / 10 20 10 30 30
Pensacola 76 95 78 91 78 / 10 30 10 30 30
Destin 79 94 79 90 80 / 10 30 20 30 40
Evergreen 70 98 74 94 74 / 05 10 10 30 30
Waynesboro 70 99 73 94 74 / 05 10 10 30 20
Camden 69 98 74 95 74 / 05 10 10 30 20
Crestview 73 97 73 93 74 / 10 30 10 30 30