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NavarreDon

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  1. YIKES!!!

    National Weather Service Mobile AL
    345 PM CST Mon Jan 8 2024

    ...New NEAR TERM, SHORT TERM, LONG TERM, MARINE...

    .NEAR TERM...
    (Now through Tuesday)
    Issued at 345 PM CST Mon Jan 8 2024

    No mincing words here, our concerns for the overnight period
    tonight is serious. A incredibly impactful system has begun across
    our area and conditions will rapidly deteriorate throughout the
    night. The potential for significant severe appears likely across
    most of the area including the potential for several significant
    tornadoes (EF-2+) and damaging winds in excess of 70 mph. While
    the current severe risk is at an enhanced, the ceiling of this
    environment could easily support a more significant severe threat
    and only minor confidence questions are holding back from higher
    severe probs. Nonetheless, these confidences may not improve until
    we see the white of its eyes and this event needs to be treated
    seriously. On top of significant severe, intense wind gusts of 50
    to 60 mph, minor to moderate coastal flooding and extremely high
    surf will all be possible overnight tonight. Coastal and wind
    impacts will likely be on the higher end for non-tropical systems
    for the Mobile area.

    I`ll keep the synoptics short here as by this point its about
    small scale things and impacts. I think we all understand by this
    point there`s a rather strong system moving through.

    Severe Threat...The makings of a significant severe thunderstorm
    threat looks likely tonight and into Tuesday morning. An intense
    low level jet will usher plenty of warm air and rich Gulf moisture
    into the area with temperatures/dew points rising nearly 20
    degrees over the next 18 hours. These factors will likely have no
    issue working instability inland across our area as the marine
    boundary lifts northward. All the high resolution guidance
    continues to have around 1000 J/KG of MLCape making its way to
    the highway 84 corridor with some guidance hinting at near 2000
    J/KG near the I-10 corridor. On top of the instability the shear
    will be absolutely insane with 0-1 KM SRH values in the warm
    sector hovering around the 500 to 700 m2/s2 and with no surprise,
    forecast soundings continue to indicate very significant low
    level curvature. Intense jet dynamics in the right entrance
    region of the upper jet will likely lead to widespread convective
    coverage beginning around midnight, likely overcoming the intense
    shear allowing for storms to rapidly organize. This event will go
    from 0 to 100 very quickly as the upper jet moves in and the
    intense low level jet increases. Rain will likely begin well
    before the severe weather arrives and things will likely go from
    showers and a few elevated thunderstorms to numerous severe storms
    in a couple hours. DO NOT LET YOUR GUARD DOWN BEFORE MIDNIGHT.

    Expect two possibly three rounds of severe weather to be possible
    with rounds two and three capable of significant severe. The
    first of three rounds is a little more conditional as the marine
    boundary moves inland. Given the shear environment, relatively
    low freezing level heights and deep EL`s, elevated storms would be
    possible with some hail probably around 1 inch in diameter. This
    will likely occur prior to midnight and in the grand scheme of
    things this threat is a mole hill compared to the mountain ahead.

    The second round is when things will begin to rapidly go downhill
    as the clock strikes midnight (or around that time). Recent high
    res-guidance continues to uptrend in the possibility of a few
    discrete to semi-discrete supercells developing along a
    confluence band ahead of the main line as the marine boundary
    lifts north shortly around midnight or just after. Given the shear
    environment and the boundary, this environment would be more than
    supportive of strong tornadoes and if these cells truly are able
    to take full advantage of the environment then the ceiling may be
    higher. The big question for higher end potential is can these
    storms sustain themselves with a lot of cell interactions,
    intense shear, modest but quickly increasing instability and stay
    within the optimal boundary spot to remain tornado producers.
    Unfortunately, some of our strongest tornadoes locally have
    occurred in environments along these marine boundaries and warm
    fronts when they are able to sustain themselves within the
    optimal boundary mode. While we are still unsure about this
    potential, the high impact nature of this period warrants great
    concern and if confidence continues to increase this would likely
    be the driving force into any potential severe upgrades heading
    into the evening.

    Then final punch will arrives shortly after round two in the 2 am
    to 8am timeframe in the form of a rather strong QLCS. This
    heavily forced squall line will only intensify as the upper jet
    overspreads and the LLJ increases. The combination of strong
    kinematics and low level instability with 0- 3km cape values
    likely approaching 100k/kg or more will support strong vertical
    stretching in a incredibly rich vorticity environment. This
    environment will truly peak east of I-65 across the western
    Florida Panhandle and into south central Alabama. Based off recent
    research this environment will be primed for QLCS tornadoes and
    given the upper echelon shear environment, strong QLCS tornadoes
    (EF-2+) could be possible. Along with the tornadoes, strong
    damaging winds will also be likely with wind gusts in excess of 70
    mph given 850 and 925 mb winds will already be high. This has the
    potential to be a rather intense severe event occurring
    overnight. Be sure to continue to stay updated and have multiple
    ways to receive warnings that are battery operated and charged as
    power may go out well before severe thunderstorms arrive.

    Wind Impacts...An extremely tight pressure gradient will develop
    over the area through tonight as the surface low pressure drops into
    the upper 980s. This will result in very windy conditions. Winds
    have already been gusting to 30 mph across the area this afternoon
    and are expected to increase into the evening. Winds well offshore
    have continued to climb with gusts to near 55 mph already. These
    winds will steadily move towards the coast this evening. A high
    end Wind Advisory has been issued for much of the area for wind
    gusts of 40-50 mph. Winds will be even higher along the coast with
    gusts up to 60 mph possible late tonight and early Tuesday
    morning as a powerful low level jet pushes into the area. A rather
    rare High Wind Warning has been issued for these coastal areas.
    The compounding impacts of increased winds and ongoing rainfall to
    saturate the soil will make trees and power lines more
    susceptible to being blown over outside of any thunderstorms.
    Because of this, power outages will be possible well before any
    severe thunderstorms arrive so it is very important to have
    multiple ways to receive warnings overnight. Be sure to charge
    battery powered methods of receiving warnings before going to bed
    and be sure to secure loose items outside.

    Beach/Coastal Hazards....Very strong onshore flow will result in
    dangerous rip currents and extremely high surf conditions at all
    area beaches. Surf heights of 10 to 15 feet are expected and will
    likely lead to beach erosion and coastal overwash along flood
    prone barrier islands. A High risk of Rip Currents is in effect
    through early this week and a High Surf Warning remains in effect
    through Wednesday morning. On top of the intense wave action,
    strong and persistent low level winds will push water inland
    leading to coastal flooding. The current forecast supports solid
    coastal flooding with coastal flood warning conditions potentially
    occurring within Mobile Bay. Given that these strong low level
    jet scenarios tend to over perform with coastal flooding, we went
    ahead and upgraded Mobile Bay to a Coastal Flood Warning. Expect
    potentially moderate coastal flooding across most of the barrier
    islands and Mobile Bay.

    Heavy Rainfall... PWATS will steadily climb in advance of the system
    with values approaching the climatological maximum for this time of
    year. This moisture combined with better instability will result in
    some heavier rain rates this afternoon and overnight. Storms will be
    capable of producing heavy rainfall in a short period of time, but
    given the progressive nature and the fact that we are still in a
    drought, there is still low confidence in significant flooding
    impacts. Most areas will likely see 2-4 inches of rainfall now
    through Tuesday with some areas potentially picking up 6 inches in
    this time frame. A localized advisory or warning cannot be ruled
    out.

    This is about as serious as it gets across our area with respects
    to impacts. Please remain weather aware tonight and have an
    emergency plan in place. Be sure to have a way to receive
    warnings that will wake you up and quickly go to your safe place.
    Prep your safe place now as power outages might make things
    difficult tonight. Trust us we do not want to be issuing tornado
    warnings at 4 am either and hopefully things find a way to pan out
    to the better. We will be right here with you through the night!
    BB/03


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    • Like 2
  2. Rare 70-knot lower level jet with sub 990-low and warm front pushing ashore.
    Even shy of severe threat, looks like non-storm related straight line winds that could gust over 50 mph.
    Storm warnings for 13-15 foot swells.
    Basically, a rare, major event for western Florida, among other places. 

    I don’t post much anymore except for tropical weather, and Mnt snow but this caught my eye and brought me over here. The Mets at MOB are great with severe weather and I don’t think I’ve seen an AFD like this from them ever! Very rare conditions for these part. Sorry for the long post but here is the disco…

    NEAR TERM...
    (Now through Tuesday Night)
    Issued at 413 PM CST Sun Jan 7 2024

    Where to begin. Probably with the fact that with the current
    trends, we have leaned towards higher confidence in an extremely
    high impact event for our area. Very strong winds, potentially
    moderate coastal flooding, high marine impacts and the potential
    for a significant severe thunderstorm event including damaging
    winds and potentially a couple significant (EF-2+) tornadoes.
    Honestly when you put all the potential impacts together this
    could be one of the more impactful non- tropical systems we ever
    had. Take this system seriously!

    Synoptic Overview...A rather potent upper low will eject into the
    Ohio River valley Monday into Tuesday night. The impressive nature
    of this system continues to be represented within ensemble
    guidance with 500 Mb heights at a climatological min within the
    ECMWF, meaning this is an anomalously deep low. With anomalously
    deep lows usually come very strong jet dynamics and right now
    looking at a 110 to 120 knot jet streak developing around the base
    of the upper low late Monday night into early Tuesday morning.
    Little further down a powerful 70 to 80 knot 850 mb jet will
    develop over our area during the same time and unfortunately
    trends within the higher resolution guidance have even hinted at
    increasing to 85+ knots. This is relatively rare territory even in
    some of our more impactful events. At the surface, these intense
    dynamics will allow for a powerful surface low to deepen into the
    upper 980s as it lifts across northeastern Arkansas. Expect rain
    to likely begin Monday afternoon as the synoptic warm front lifts
    northward and persisting throughout the overnight hours. Rain may
    become intermittent for a brief period before the final line of
    storms pushes through early Tuesday morning likely clearing out as
    we approach the noon Tuesday timeframe. Given how dynamic this
    system is we expect a plethora of hazards to come.

    Severe...Unfortunately, things trended the wrong way for us
    amongst the high resolution guidance and the makings of a
    significant severe thunderstorm threat appears on our doorstep. As
    mentioned in yesterdays afd, extreme environments tend to end in
    extreme results and the expected environment is quickly trending
    towards extreme. Going into yesterday the limiting factor was the
    instability. As worried, the proximity to rich Gulf Moisture
    coupled with the intense low level wind field should have no
    issued working instability inland across our area as the marine
    boundary lifts northward. All the high resolution guidance has
    around 1000 J/KG of MLCape making its way to the highway 84
    corridor with some guidance hinting at near 2000 J/KG near the
    I-10 corridor and has trended upward with time. Not great Bob,
    when that was suppose to be the limiting factor. On top of the
    instability the shear will be ludicrous with that 80 knot LLJ. 0-1
    KM SRH values in the warm sector are hovering around the 500 to
    600 m2/s2 with insane low level curvature and high streamwise
    component. It would be immature to not at least mention that
    sometimes these shear environments can be too much especially with
    lower amounts of instability much like last years; however,
    intense jet dynamics in the right entrance region of the upper jet
    will likely overcome all of those issues. Expect two rounds of
    severe weather to be possible with both capable of significant
    severe. The first round is a little more conditional as
    instability and synoptic ascent will be more limited compared to
    round two. However, this round will be along the lifting marine
    boundary around midnight. This will likely involve embedded
    supercells lifting with the boundary leading to the potential for
    damaging winds and tornadoes. Given the shear environment and the
    boundary, a strong tornado cannot be ruled out. Then the real show
    arrives shortly after and persists through the overnight in the
    form of a rather strong QLCS. This heavily forced squall line will
    only intensify as the upper jet overspreads and the LLJ
    increases. The combination of strong kinematics and low level
    instability with 0-3km cape values likely approaching 100k/kg or
    more will support strong vertical stretching in a incredibly rich
    vorticity environment. QLCS tornadoes will likely be common with
    this line including the potential for a few strong QLCS tornadoes
    (EF-2+). Along with the tornadoes, strong damaging winds will also
    be likely with wind gusts in excess of 70 mph given 850 and 925
    mb winds will already be high. This has the potential to be a
    rather intense severe event occurring overnight. Be sure to
    continue to stay updated and have multiple ways to receive
    warnings that are battery operated and charged as power may go out
    well before severe thunderstorms arrive.

    Beach/Coastal Hazards....Given the anomalously low pressures and
    tight gradient winds it will be outright howling across the marine
    waters. Winds have only trended upward since yesterday. Given the
    incredibly long fetch of strong winds, seas will quickly climb to
    high surf warning criteria. Surf heights along the coast Monday
    night through Tuesday will likely approach 10 feet plus leading to
    likely beach erosion, life threatening surf and rip currents and
    likely coastal overwash along flood prone barrier islands. On top
    of the intense wave action, strong low level winds will also push
    water leading to coastal flooding. Current PETSS guidance supports
    at least solid coastal flooding and with current trends we are
    quickly approaching coastal flood warning criteria Monday evening
    for Mobile Bay. For now the plan will be for a coastal flood
    advisory in the coming packages as confidence increases and we
    will have to monitor closely for a possible coastal flood warning.
    Nonetheless, the usual flood prone areas should expect at least
    minor to possibly moderate coastal flooding and overwashing.

    Wind Impacts...As if the rest of the discussion didn`t spell it
    out, it is going to be windy. Winds have trended upward with most
    of the area likely seeing gusts up to 50 mph even as far inland as
    highway 84. Along the coast winds will be peaked with gusts up to
    60 mph possible as the strong low level jet and instability move
    inland. A rather rare high wind warning has been issued for the
    coastal areas with a high end wind advisory for the remainder of
    the area. The compounding impacts of increased winds, weekend
    trees from the last few months of drought and rainfall saturating
    the soil will likely lead to trees coming down across the area.
    Power outages will be possible well before any severe
    thunderstorms arrive which could lead to a nasty combination.
    Charge battery powered methods of receiving warnings before going
    to bed and be sure to secure loose items outside.

    Heavy Rainfall Impacts...Confidence in rainfall happening is high
    but the heavy rainfall and flooding does It seem as likely outside
    of maybe a few urban areas. PWATS will steadily climb in advance
    of the system and elevated instability north of the lifting warm
    front Monday evening will allow for a shot for some heavier rain.
    The issues are 1. we are still dry from the last few months. 2.
    the rather quick moving nature, especially with the second line
    could force things to be fully rate driven and not sure we get the
    rates long enough to overcome our relatively high flash flood
    guidance. If that first round of rain Monday evening is stronger
    and or the warm front gets hung up along the coast, then we might
    see some minor flash flood concerns develop. Right now the best
    area for heaviest rain is across southeastern Mississippi before
    the eventual squall line gets moving east. This is honestly a
    rather low confidence flooding situation and will likely be driven
    heavily on the progression of the warm front and rain rates.

    All and all Monday night into Tuesday looks to be impactful for
    our area with or without strong thunderstorms. The environment has
    continued to come together the full gambit of impacts are
    becoming likely. Keep up to date with this system as potential
    impacts may change as we get more details. BB/03


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    • Like 3
  3. Yesterday 10/10/23 was the 5 year anniversary of Michael’s landfall on the Florida panhandle. With family still in St Joe Beach, we head over from Navarre 3/4 times a year. The progress is amazing but the scars still remain. Here is a special that WJHG in Panama City did on the anniversary yesterday.

     

     

     

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    • Like 2
  4. 000
    WTNT65 KNHC 300157
    TCUAT5

    Hurricane Idalia Tropical Cyclone Update
    NWS National Hurricane Center Miami FL AL102023
    1000 PM EDT Tue Aug 29 2023

    ...IDALIA FORECAST TO BECOME A MAJOR HURRICANE TONIGHT...
    ...CATASTROPHIC STORM SURGE AND DESTRUCTIVE WINDS LIKELY TOMORROW
    MORNING WHERE THE CORE OF IDALIA MOVES INLAND...

    NOAA and Air Force Reserve Hurricane Hunter aircraft data indicate
    that Idalia has strengthened further. Maximum sustained winds have
    increased to 110 mph (175 km/h). The minimum pressure based on
    dropsonde data from the aircraft has fallen to 960 mb (28.35
    inches).

    The National Hurricane Center has begun hourly position and
    intensity updates on Idalia. The hourly updates will continue as
    long as Idalia's eye is easily trackable in ground-based radar data.

    SUMMARY OF 1000 PM EDT...0200 UTC...INFORMATION
    ----------------------------------------------
    LOCATION...27.4N 84.6W
    ABOUT 135 MI...215 KM WSW OF TAMPA FLORIDA
    ABOUT 205 MI...330 KM S OF TALLAHASSEE FLORIDA
    MAXIMUM SUSTAINED WINDS...110 MPH...175 KM/H
    PRESENT MOVEMENT...N OR 10 DEGREES AT 18 MPH...29 KM/H
    MINIMUM CENTRAL PRESSURE...960 MB...28.35 INCHES


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    • Like 4
  5. Dry air to the north still remains upshear of the storm. While this recent pulse is the most impressive we've seen, Idalia hasn't done much to moisten the environment ahead of it, as such this dry air will continue be pushed into and entrained within the circulation. Unlikely that this current convection over the center will maintain itself long enough to facilitate substantial organization before dry air eats away at it a bit.

    Dr. Cowan’s video has some great info on this!




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  6. Levi has a great video up on Tidbits from yesterday. He goes into good detail with info on LL & UL atmosphere conditions that should affect 93L’s development. 6Z GFS looks odd to me but I’m no expert. Definitely have an eye towards this here in Navarre.


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