Small Craft Advisory 28, NWS Mobile, AL

284 
WHUS74 KMOB 270248
MWWMOB

URGENT - MARINE WEATHER MESSAGE
National Weather Service Mobile AL
948 PM CDT Sun Apr 26 2020

GMZ631-632-650-655-670-675-271100-
/O.CON.KMOB.SC.Y.0028.000000T0000Z-200427T1500Z/
Southern Mobile Bay-Mississippi Sound-
Coastal waters from Pensacola FL to Pascagoula MS out 20 NM-
Coastal waters from Okaloosa Walton County Line FL to Pensacola
FL out 20 NM-
Waters from Pensacola FL to Pascagoula MS from 20 to 60 NM-
Waters from Okaloosa Walton County Line FL to Pensacola FL from
20 to 60 NM-
948 PM CDT Sun Apr 26 2020

...SMALL CRAFT ADVISORY REMAINS IN EFFECT UNTIL 10 AM CDT
MONDAY...

* WHAT...North winds around 20 kt with frequent gusts up 
  to 25 kt expected.

* WHERE...Portions of the coastal waters of Alabama and 
  northwest Florida. 

* WHEN...Until 10 AM CDT Monday.

* IMPACTS...Conditions will be hazardous to small craft.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Inexperienced mariners, especially those operating smaller
vessels, should avoid navigating in hazardous conditions.

&&

$$

247 
WHUS74 KMOB 271021
MWWMOB

URGENT - MARINE WEATHER MESSAGE
National Weather Service Mobile AL
521 AM CDT Mon Apr 27 2020

GMZ631-632-650-655-670-675-271500-
/O.CON.KMOB.SC.Y.0028.000000T0000Z-200427T1500Z/
Southern Mobile Bay-Mississippi Sound-
Coastal waters from Pensacola FL to Pascagoula MS out 20 NM-
Coastal waters from Okaloosa Walton County Line FL to Pensacola
FL out 20 NM-
Waters from Pensacola FL to Pascagoula MS from 20 to 60 NM-
Waters from Okaloosa Walton County Line FL to Pensacola FL from
20 to 60 NM-
521 AM CDT Mon Apr 27 2020

...SMALL CRAFT ADVISORY REMAINS IN EFFECT UNTIL 10 AM CDT THIS
MORNING...

* WHAT...North winds 15 to 20 kt with frequent gusts up to 25 kt 
  expected.

* WHERE...Gulf coastal waters of Alabama and northwest Florida,
  including southern Mobile Bay and the Mississippi Sound. 

* WHEN...Until 10 AM CDT Monday.

* IMPACTS...Conditions will be hazardous to small craft.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Inexperienced mariners, especially those operating smaller
vessels, should avoid navigating in hazardous conditions.

&&

$$

Area Forecast Discussion
National Weather Service Mobile AL
313 PM CDT Sun Apr 26 2020

.NEAR TERM UPDATE /Now Through Monday/...Tonight, cooler, drier
air will continue to push south across the forecast area, with
temperatures dropping into the mid to upper 40s over much of the
forecast area, low 50s close to the coast. As surface high
pressure over the Mississippi River shifts east, winds overnight
are expected to remain above light levels, around 5 knots or so.
With the better overnight mixing, the aforementioned temperatures
are a bit above guidance.

Monday, the surface high pressure shifts east to near the Eastern
seaboard, bringing a shift in winds from northerly to
southeasterly by the end of the day. With the loss of the cooler
northerly flow, combined with clear skies, good daytime heating is
expected. Still the cooler air that has moved over the Southeast
will keep daytime high temperatures from rising above the mid to
upper 70s over the forecast area. /16

&&

.SHORT TERM /Monday night Through Wednesday night/...The short term
begins with a period of northwest flow aloft quickly becoming more
zonal as a deep upper-level trough rotates eastward from the eastern
CONUS over the Atlantic Ocean. Meanwhile at the surface, high
pressure builds east from the Southeastern CONUS into the western
Atlantic, shifting winds to more southerly by Tuesday and beginning
the gradual process of transporting Gulf moisture back into the
region. As a result, we see temperatures reach the mid 80s Tuesday
afternoon as dewpoints (and therefore low temps) climb back into the
low to mid 60s Tuesday night.

A weak shortwave ejects from the central Rockies southeastward
across the Great Plains and into the lower Mississippi Valley
Tuesday. The upper pattern becomes more complex thereafter as a more
potent upstream shortwave trough, lagging behind the aforementioned
wave, ejects and rapidly deepens as it approaches the Midwest and
Great Lakes regions by Tuesday night. A surface low subsequently
develops along the NE/SD border and deepens as it advances east
towards the Great Lakes, with an attendant cold front surging
southeast into the southern Mississippi Valley by early Wednesday
morning.

The initial weaker shortwave fills in as it traverses the Deep South
and shouldn't provide much more than some increased coverage in high
clouds across the local area late Tuesday. The more amplified upper
trough rotates through the eastern CONUS on Wednesday. As this
occurs, the cold front pushes into our area, with showers and
thunderstorms expected along and ahead of it. At this time, the
environment ahead of FROPA appears marginally supportive of a few
strong to possibly severe storms. The best upper-level dynamics remain
well to our north and as a result, mid- and upper- level flow are
lacking for much of the day Wednesday. Do see some signal of a
decent 40+ knot 850 mb LLJ setting up Wednesday morning that acts
to lengthen low-level hodographs, granted shear would be mostly
confined to the 0-3 km layer as the stronger 500-300 mb flow
doesn't overspread the area until later in the day when the LLJ
has weakened and shifted northeast. In terms of instability, most
guidance shows roughly 1000-1500 J/kg MLCAPE developing with the
onset of daytime heating Wednesday afternoon/evening. Biggest
question remains whether timing of best dynamics and instability
will overlap enough for storms to become severe. If so, the window
likely occurs sometime Wednesday afternoon/evening and would
consist of a low-end threat for multicell clusters capable of
producing gusty winds and possibly some hail. Will continue to
monitor this system over coming days and provide updates as
needed.

North winds usher in a drier and cooler airmass Wednesday night in
the wake of the FROPA. Rain chances quickly taper from west to east
and low temps dip into the low 50s inland and upper 50s to around 60
along the immediate coast. /49

&&

.EXTENDED TERM /Thursday Through Sunday/...There is good
agreement between both spectral model solutions and GEFS regarding
the placement and magnitude of large scale features over our
region this period. The period is forecast to be dry. Thursday
morning begins with both slight low-level cold- and dry-air
advection, large scale subsidence and with a deep layer of dry
air. Surface winds turn more easterly then southerly during the
day on Friday as relatively weak (<1020 hPa) surface high
pressure builds across from the west (before eventually splitting
into two separate high pressure cells, one over the NE GLFMEX and
a second that will eventually be located just east of the FL
Peninsula over the SW Atlantic by period's end). Continuing with
the evolutionary progression, by late Saturday remnants of the
deep NW mid- and upper flow will finally no longer be evident and
the pattern gives way after Saturday night to upstream deep layer
ridging that will build over the entire Central Gulf Coast region
through early next week. This will keep winds, overall, on the
lighter side due to a  weak synoptic pressure gradient but daily
afternoon sea- and bay- breezes will be quite stout likely 13-18
kts each afternoon, and higher in gusts. Summer-like heat is
forecast to return on Sunday with lower 90s F across the board,
except mid 80s right along the beaches. Clouds do increase from
the west late on Sunday- so will have to monitor the impact on
Sunday afternoon highs given any timing errors. Overall, the
period begins cool and dry and gradually moistens and warms
through the period. The mid- and upper ridging does look like it
will break down after next Sunday and the flow will become more
zonal again, ushering in yet another possible pattern change. So,
afternoon highs in the mid and upper 70s F on Thursday gradually
warming into the mid 80s to lower 90s F by Sunday. Nighttime lows
mainly in the 50s F (lower 60s beaches) will warm into the 60s by
Sunday. /23 JMM

&&

.MARINE...Moderate to strong flow forecast tonight as temperatures
cool over land, allowing stronger winds aloft to flow out over
relatively warmer Gulf waters. Surface high pressure will pass
north of the forecast area beginning late tonight, bringing a
shift in winds to southeasterly by then end of the day Monday,
along with a lighter wind flow. Flow remains onshore into mid week,
with some strengthening as a cold front approaches. Moderate to
strong offshore flow follows the front's passage late Wednesday
and into Wednesday night. Surface high pressure moves east over the
Southeast late Thursday night into friday night, bringing onshore
flow back to area waters by Friday night. /16

&&

.MOB WATCHES/WARNINGS/ADVISORIES...
AL...None.
FL...None.
MS...None.
GM...None.
&&

This product is also available on the web at:
http://weather.gov/mob

Hazardous Weather Outlook...UPDATED
National Weather Service Mobile AL
314 PM CDT Sun Apr 26 2020

ALZ051>060-261>266-FLZ201>206-MSZ067-075-076-078-079-272015-
Choctaw-Washington-Clarke-Wilcox-Monroe-Conecuh-Butler-Crenshaw-
Escambia-Covington-Mobile Inland-Baldwin Inland-Mobile Central-
Baldwin Central-Mobile Coastal-Baldwin Coastal-Escambia Inland-
Escambia Coastal-Santa Rosa Inland-Santa Rosa Coastal-
Okaloosa Inland-Okaloosa Coastal-Wayne-Perry-Greene-Stone-George-
314 PM CDT Sun Apr 26 2020

This Hazardous Weather Outlook is for portions of south central
Alabama...southwest Alabama...northwest Florida and southeast
Mississippi.

.DAY ONE...Through Tonight

No hazardous weather is expected at this time.

.DAYS TWO THROUGH SEVEN...Monday through Saturday

A few strong to severe thunderstorms will be possible by early
Wednesday morning and into the afternoon, but it is now looking
like the greatest threat will be confined to north of the Highway
84 Corridor. At this time, coverage does not look to be that
great. We will continue to monitor next few days.

.SPOTTER INFORMATION STATEMENT...

Activation of SkyWarn Severe Storm Spotter networks is not
expected through Saturday.

GMZ630>636-650-655-670-675-272015-
Northern Mobile Bay-Southern Mobile Bay-Mississippi Sound-
Perdido Bay-Pensacola Bay System-Western Choctawhatchee Bay-
Eastern Choctawhatchee Bay-
Coastal waters from Pensacola FL to Pascagoula MS out 20 NM-
Coastal waters from Okaloosa Walton County Line FL to Pensacola
FL out 20 NM-
Waters from Pensacola FL to Pascagoula MS from 20 to 60 NM-
Waters from Okaloosa Walton County Line FL to Pensacola FL from
20 to 60 NM-
314 PM CDT Sun Apr 26 2020

This Hazardous Weather Outlook is for portions of the coastal
waters of Alabama and northwest Florida.

.DAY ONE...Through Tonight

A small craft advisory later tonight for strong offshore winds picking
up by mid evening.

.DAYS TWO THROUGH SEVEN...Monday through Saturday

Increasing onshore flow and a build in seas is anticipated for the
Tuesday night and Wednesday time frame. Winds, waves and seas locally
higher near mid week storms. Expect daily strong afternoon sea-
and bay- breezes from Wednesday through Saturday, even in the
wake of the mid-week front. It will most likely create Small
Craft Exercise Caution conditions each afternoon for several
hours.