688 
FXUS64 KMOB 311202
AFDMOB

Area Forecast Discussion
National Weather Service Mobile AL
602 AM CST Mon Jan 31 2022

.AVIATION...
12Z issuance... Some brief patchy MVFR/IFR fog is possible 
through the early morning hours before sunrise, with this 
currently affecting VISBY's at TAF site BFM. These conditions will
quickly dissipate as the sun rises, with VFR conditions expected
after sunrise and through the rest of the period. Brief patchy 
light fog could be possible again early tommorow morning, however, 
confidence remains low as of the current forecast. Winds remain 
light (at times calm) west-southwest/variable through the early 
morning hours. Winds then increase to around 5-10kts by mid 
morning, and transistion to southerly by the afternoon. Overnight 
winds relax once more, becoming light southeasterly/variable (at 
times calm) overnight. Mostly clear skies expected through today,
but clouds do begin to gradually increase from the southwest 
going into late tonight. JEH/88



&&

.PREV DISCUSSION... /issued 452 AM CST Mon Jan 31 2022/ 

NEAR TERM UPDATE /Now Through Tuesday/...The near term period
remains dry with Tuesday setting the stage for a rather wet period
to close out the work week. Ridging aloft off to our west 
continues to track east moving over the region today. Northwest 
flow aloft will quickly give way to southwesterly flow as the 
ridging quickly moves east of the region by the late afternoon 
with a shortwave trough over west central TX pivoting southeast 
into the northwest Gulf going into tonight. This feature then 
continues tracking east across the Gulf through Tuesday. At the 
surface, through today surface high pressure continues moving east
across the gulf resulting in a west-southwest surface flow 
through the day. Tonight, the surface high moves east of the 
region and strong surface ridging then begins to builds along the 
eastern seaboard as a new trough begins to develop and amplify 
over the western CONUS. As this ridging builds into our region 
from the northeast, and with the surface high today moving east of
the area, surface flow gradually transitions to more 
southeasterly by tonight and into Tuesday while also increasing in
speed slightly due to a tightening gradient. With this pattern, 
dry but warmer conditions are overall supported through the 
period. Given the lack of moisture heretofore precip is not 
expected through Tuesday; however, moisture does begin to
gradually increase through Tuesday as surface flow increases 
from the southeast. With this, increasing clouds are expected 
through the period as well. By Tuesday evening, a few showers 
could be possible over southeast MS, but given the limit of 
overall forcing up to this point chances remain slim for precip 
development through the near term period. 

With mostly clear skies expected today and ridging overhead, still
expecting temps to be on the warmer side today with highs climbing
into the mid to upper 60s today with the aid of southwest surface
flow. Tonight will also be slightly warmer as moisture advection 
off the Gulf slowly increases dewpoints leading to warmer lows. 
Expect lows tonight to range generally in the low to upper 40s 
across the area. By Tuesday, the warmth continues as highs will 
likely be in the upper 60s to low 70s. One caveat would be the 
increasing cloud cover from the southwest helping to limit 
temperatures from really getting up there for this time of the 
year. Some patchy fog remains possible mainly north of I-10 early 
this morning and tonight. Dewpoints are still on the low side for 
good fog production, but there is some hints of at least patchy 
fog with visibilities to around 1 mile. This will be especially 
true over interior areas where winds could relax and radiational 
cooling can fully take over. Lastly, a High risk of rip currents 
in now in effect beginning Tuesday. JEH/88

SHORT TERM /Tuesday night Through Wednesday night/...An upper
ridge over the eastern seaboard will move over the western 
Atlantic by Wednesday morning, and continue shifting eastward
through the remainder of the short term. A very large positively
tilted upper trough will extend southwestward from central Canada 
to off the southern California Coast. This upper trough will shift
eastward and extend from the Upper Midwest to the Desert Southwest
by late Wednesday night. A strong surface ridge along the eastern
U.S. seaboard will persist through Tuesday night, and then weaken
through midweek as a strong cold front approaches the region from
the northwest. Southeasterly to southerly low level wind flow 
will persist through the period between these two features. This 
will allow enhanced boundary layer moisture to be drawn northward 
from the Gulf and into our area, especially midweek as a deeper, 
moist southerly flow sets up across the region. Precipitable water
values are expected to slowly increasing to between 1.00 to 1.25 
inches through the period. Over-running along the southwest 
periphery of the weakening surface ridge will result in isolated 
to scattered showers developing across southeast MS and southwest 
AL Tuesday night. This precipitation will expand eastward through 
late Wednesday afternoon, with numerous showers expected west of 
the Tombigbee River and scattered showers to the east. Scattered 
showers are then expected area-wide Wednesday night. Instability 
still looks to be lacking with very little CAPE available, so have
not included any mention of thunderstorms anywhere in the short 
term period. 

Mild temperatures will occur through the short term with lows
Tuesday night in the low to mid 50s. Highs on Wednesday will be 
in the mid 60s to lower 70s. Lows Wednesday night will only lower 
into the mid 50s to lower 60s. /22

EXTENDED TERM /Thursday Through Sunday/...A longwave positively 
tilted upper trof centered generally over the central states takes 
on a more meridional orientation while continuing across the
interior eastern states through early Saturday morning. By
Thursday morning, a strong cold front will extend from the 
northeast states to the lower Mississippi River valley, and the 
front is expected to push through the forecast area Thursday 
night. As the upper trof advances eastward, a region of strong 
deep layer lift is expected to shift eastward across the region as
the cold front moves through the area. Deep layer southerly flow 
already in place over the area strengthens in response on 
Thursday, with the 850 mb jet increasing to 45-55 knots with 
similar values persisting Thursday night until the front moves 
through the area. This strengthening southerly flow brings 
abundant Gulf moisture into the region, with precipitable water 
values of 1.0-1.3 inches Thursday morning increasing to around 1.9
inches as the front moves through. This unusually abundant amount
of deep layer moisture over the area combined with strong deep 
layer lift shifting across the region looks to result in rainfall 
amounts of 2.0-2.5 inches (with locally higher amounts). The event
will be progressive in character, but these heavy rainfall amounts
could at least lead to some nuisance type flooding concerns and 
some isolated flash flooding will be possible and will need to be 
closely monitored. High shear values will be in place over the 
forecast area on Thursday, but the amount of instability now looks
to be more limited than indicated earlier with SBCAPE values of 
less than 150 J/kg, and even MUCAPE values look to be at best 400 
J/kg at the coast. Should even a modest increase in instability 
pan out, this would quickly bring an increasing risk of severe 
thunderstorm development potential and will need to be closely 
monitored over the coming shifts. A high risk of rip currents is 
also expected to be in effect on Thursday. Have continued with 
likely to categorical pops for Thursday into Thursday night as the
front moves through. There is the potential for an overrunning 
flow to linger in the wake of the front on Friday until an 850 mb 
trof moves through, and have kept slight chance to chance pops for
roughly along and east of I- 65, with dry conditions expected 
areawide by early Friday evening and continuing through the 
weekend. After mild temperatures on Thursday with highs mostly in 
the lower 70s, much colder air flows into the area in the wake of 
the front and highs on Friday range from the upper 40s over 
interior southeast Mississippi and interior southwest Alabama 
ranging to near 60 over part of the western Florida panhandle. 
Lows Thursday night will dip down to the mid to upper 30s over 
interior southeast Mississippi and interior southwest Alabama, 
but model soundings currently indicate that any precipitation that
falls will be as a cold rain without a potential for wintry 
precipitation before the rain comes to an end. Lows Friday night 
range from the mid to upper 20s well inland to the mid 30s at the 
coast, and highs on Saturday range from the upper 40s to mid 50s. 
Lows Saturday night will moderate just somewhat compared to Friday
night, and highs on Sunday look to be in the 50s. /29

MARINE...A light westerly to northwesterly flow expected through 
today as a surface high pressure moves across the marine waters.
By tonight, winds transition into southeasterly and are expected 
to increase to small craft exercise caution conditions again. A 
moderate to strong southeast flow with building seas is expected 
by Tuesday morning, with a strong onshore flow and continuing 
building seas expected by Tuesday afternoon. These conditions are 
expected to continue into mid to late week as the next system 
approaches. A Small Craft Advisory is now in effect beginning 
Tuesday afternoon and lasting through late in the week. Occasional
gale force gust could be possible, but trends right now do not 
support this. Will continue to monitor. JEH/88

&&

.MOB WATCHES/WARNINGS/ADVISORIES...
AL...High Rip Current Risk from Tuesday morning through late Friday 
     night for ALZ265-266.

FL...High Rip Current Risk from Tuesday morning through late Friday 
     night for FLZ202-204-206.

MS...None.
GM...Small Craft Advisory from noon Tuesday to 6 AM CST Saturday for 
     GMZ650-655-670-675.

&&

$$

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