Area Forecast Discussion
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FXUS62 KTAE 220732

Area Forecast Discussion
National Weather Service Tallahassee FL
232 AM EST Mon Jan 22 2018

.NEAR TERM [Through Today]...

In the upper levels a trough will be over the Lower Mississippi
Valley today. At the surface a low centered over Iowa will continue
to move northeast. A cold front will approach the region this
afternoon and pass through overnight and into Tuesday morning.
Instability will be low ahead off this system with CAPE near 300
j/kg and dew points in the lower 60s. However deep layer shear
around 50 knots is favorable for severe weather. With low
instability and favorable shear a marginal risk for severe weather
exists today from mid afternoon through early evening mainly west of
a line from Dothan to Panama City. This line of storms will weaken
as it moves eastward through Southwest Georgia and the Florida Big
Bend tonight. Expect mostly cloudy skies today with highs mainly in
the lower 70s.

.SHORT TERM [Tonight Through Wednesday]...

The occluded upper low will move into the Midwest overnight, with
the surface front making it just about halfway through the Tri-
State region by dawn. As mentioned above this is a typical high
CAPE/low shear event which tend to carry a marginal risk for
severe weather. It`d be hard to imagine anything but elevated
storms east of the Apalachicola and Chattahoochee rivers with
water temperatures in Apalachee Bay hovering right around 50
degrees and a full day of modest onshore flow. West of the rivers,
instability will likely be diurnally driven and should be waning
in the evening hours. Thus expect the threat for any strong to
severe storms to be lessening through the evening hours. Though a
low-end threat, all types of severe weather would be possible,
where surface based convection is favored, given 50-60kts of deep
layer shear, 25kts of low-level shear and favorable hodographs,
rather steep mid-level lapse rates and cool temps aloft. Storms
will likely be more of the discrete variation as they`ll be pre-
frontal, at least prior to midnight.

Showers associated with the front should clear the southeast Big
Bend by early afternoon, with highs ranging from the low 60s in
southeast Alabama, up to the low 70s in the southeast Big Bend. In
the warmer Big Bend and south-central Georgia locations, highs
will be met prior to the passage of the front and will gradually
cool through late afternoon. Expect lows to dip into the upper 30s
to near 40 degrees Tuesday night, with sunny skies and highs in
the upper 50s to low 60s on Wednesday.

.LONG TERM [Wednesday Night Through Monday]...

Expect dry conditions to continue through the end of the week as
deep layer ridging prevails. Highs will gradually climb through
the 60s, with lows in the upper 30s. Over the weekend, a northern
stream trough moving through the eastern CONUS will merge with the
southern stream, and eventually push a cold front through the
region by Monday morning. Ahead of the front, veering low layer
flow and a southern stream wave will support a large area of
isentropic rain spreading into the northeast Gulf, at least as
far as north Florida. At this time models differ considerably
regarding the placement of this rain shield and thus our average
rain amounts with the weekend system could range from an inch or
less to 1-3".


.AVIATION [Through 06Z Tuesday]...

MVFR conditions are likely tonight with some IFR CIGs possible.
Conditions will improve slightly by mid morning but MVFR CIGs will
likely remain throughout the day. Thunderstorms are possible at ECP
and DHN late in the afternoon. This activity will weaken as it moves
eastward and rain is expected after sunset for ABY, TLH and VLD.



Cautionary level winds and seas are forecast to begin on Tuesday
in the wake of a cold front and last until the end of the week
when conditions should continue to deteriorate to Advisory levels
ahead of our next frontal system. Expect showers and thunderstorms
late today through tonight and again this upcoming weekend.



Dry air will move into the region by Tuesday morning as a cold front
moves through. Minimum relative humidity values will likely remain
above 30 percent this week. Patchy fog is possible this morning.
Rain is likely this evening and overnight.



Average rain amounts associated with today and tonight`s frontal
system will range from 0.25-1", with the highest amounts expected
in the southeast Big Bend of Florida. Isolated higher amounts
would likely be less than 2". This weekend brings another chance
for rain, though just how much is quite uncertain. Additional
amounts could range from an inch or less to 1-3".



Spotter activation is not requested. However, spotters are always
encouraged to safely report significant weather conditions when they
occur by calling the office or tweeting us @NWSTallahassee.



Tallahassee   69  58  68  40  61 /  40  70  10   0   0
Panama City   68  57  63  43  57 /  70  60   0   0   0
Dothan        71  49  62  36  58 /  50  60   0   0   0
Albany        71  55  64  37  58 /  20  60  10   0   0
Valdosta      73  62  69  40  60 /  20  70  20   0   0
Cross City    76  62  72  41  62 /  20  80  40   0   0
Apalachicola  66  60  66  45  58 /  60  70  10   0   0




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LONG TERM...Harrigan
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