1/17 – Rob’s “Treacherous Travel” Forecast

An arctic airmass will be firmly entrenched across the Gulf South
today. Strong subsidence and dry air advection will also continue.
As a result, clear skies, cold temperatures, and low relative
humidities can be expected through the day.
Only expect to see high temperatures above freezing for a few
hours this afternoon. There will be some melting of the snow and
ice during this period, but there will still be lingering snow and
ice heading into tonight. Breezy conditions will also persist, and
this will keep wind chills in the 20s this afternoon. Wind chill
advisories remain in effect for the entire forecast area for the
morning hours when wind chills are expected to be in the single
digits and teens. Fortunately, even though temperatures will
plunge back into the teens and lower 20s tonight, winds will be
lighter. The wind chill should be fairly close to the actual air
temperature, so a wind chill advisory will not be needed.

The heart of the arctic cold pool will finally begin to pull away
from the area tomorrow, and a more zonal flow pattern will develop
in the mid and upper levels. Temperatures should begin to modify a
bit with highs rising into the middle 40s by Thursday afternoon.
This modification in temperatures will continue into Thursday
night as lows only dip into the 20s and lower 30s. A hard freeze
will likely occur over the northern half of the forecast area once
again. Some high level cloud cover should also begin to feed into
the area Thursday night and Friday as a weakening short wave
trough approaches from the west. This system looks to be moisture
starved in the low levels, and do not have a mention of rain in
the forecast for Friday or Friday night. Temperatures will
continue to gradually modify, and expect to see highs in the
middle 50s Friday afternoon. Lows on Friday night should finally
remain above freezing across the CWA.

No significant changes in thinking heading into the weekend and
first part of next week. A shortwave ridge axis will pass directly
over the forecast area Saturday into Saturday night. This increase
in ridging will keep a stable airmass in place across the Gulf
South, and could also support the formation of an advection fog
event Saturday night into early Sunday morning. Temperatures will
continue to warm as deep layer southerly flow takes hold, and
moisture will also return into the region from the central Gulf of
Mexico. With increasingly warm and moist air moving over the
cooler nearshore waters, the prospect of sea fog increases
dramatically for Saturday night. Temperatures will be in the upper
60s Saturday afternoon before dipping into the lower 50s Saturday
night. Dewpoints will also increase into the upper 40s and lower
50s by Saturday night. Winds should also remain light enough to
allow for fog to develop as opposed to a low status deck. Given
all of the aforementioned conditions, have included fog in the
forecast for Saturday night.

The fog could linger for a few hours Sunday morning, but a rapidly
approaching neutrally tilted shortwave trough and associated cold
front will increase turbulent mixing and buoyancy across the
region from late Sunday morning through the afternoon hours.

The better chances for rain will be Sunday night when the cold
front pushes across the forecast area. Have likely chance of rain of around
60 percent in the forecast. Looking at thermodynamic and shear
parameters, it looks like a line of showers and scattered
thunderstorms should push across the area.

Once the front and associated line of convection pushes through
Sunday night, a much quieter weather pattern will develop for the
first half of next week. Zonal flow will dominate, and
temperatures will be near seasonal averages each day. Highs should
climb into the lower 60s, and lows will dip into the upper 30s and
40s each day. A dry and stable airmass will be in firm control of
the forecast area, and expect to see mostly clear skies in place.