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NavarreDon

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    Pretty remarkablly anomolous severe event Jan. 8/9 over panhandle

    in Southeastern States

    Posted

    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

    Hurricane Michael 5 years later

    in Tropical Headquarters

    Posted

    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

    Hurricane Idalia

    in Tropical Headquarters

    Posted

    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

    Hurricane Idalia

    in Tropical Headquarters

    Posted

    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!




    .

    Hurricane Idalia

    in Tropical Headquarters

    Posted

    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.


    .

    • Thanks 1

    2022-2023 Fall/Winter Mountains Thread

    in Southeastern States

    Posted

    Lots of love for WNC on the weather channel! Not telling you folks anything you don’t know but low placement & strength are going to be key in this one. Really hard for the models to pinpoint this. Synoptically the far SW Mnts except at high elevations will have boundary layer issues, the escarpment areas do well, the Balsams rake, the French Broad valley snow hole may appear, the Northern Mnts will have great variations but will generally over preform, the Foothills will be very tricky. Will be a exciting and frustrating chase for you guys. All in all a typical southern winter system for WNC!


    .

    • Like 4

    Julia | 85 mph 982 mb peak | EPAC Crossover #2

    in Tropical Headquarters

    Posted

    000
    WTNT43 KNHC 071455
    TCDAT3

    Tropical Storm Julia Discussion Number 5
    NWS National Hurricane Center Miami FL AL132022
    1100 AM EDT Fri Oct 07 2022

    Earlier this morning, a concentrated burst of deep convection with
    a high density of lightning developed near the center of the
    cyclone while it was over the Guajira Peninsula, and microwave
    imagery shows that convective banding has increased somewhat over
    the adjacent waters. An Air Force Reserve Hurricane Hunter aircraft
    currently investigating the system so far has found maximum 925-mb
    flight-level winds of 47 kt and SFMR surface winds of 34 kt, and on
    that basis, the depression is upgraded to a 35-kt tropical storm.

    Based on the latest aircraft fix, Julia is moving a bit faster
    toward the west than expected with an initial motion of 280/16 kt.
    A strong east-northeast to west-southwest oriented ridge which
    stretches into the southern Gulf of Mexico should keep Julia on a
    quick westward path during the next 48 hours. Since the track
    guidance has sped up a bit over the past few forecast cycles, the
    official forecast now brings Julia to the coast of Nicaragua by
    Sunday morning, which is a little sooner than was previously
    forecast. After landfall, the track guidance currently indicates
    that Julia and its remnants should remain over Central America and
    southern Mexico through Tuesday.

    Stiff north-northwesterly shear (15-20 kt) is affecting Julia, and
    that can be seen in the suppression of the northern edge of the
    recent convective burst. Shear diagnostics suggest that this shear
    should abate soon, and Julia should commence a steady strengthening
    trend during the next two days while it crosses the southwestern
    Caribbean Sea. Julia is forecast to become a hurricane by Saturday
    evening, and the forecast peak intensity at the time of landfall in
    Nicaragua is unchanged from the previous advisory. The official
    forecast at that time is a bit above HCCA and the IVCN consensus
    aids, but it's still below SHIPS and LGEM guidance. The NHC
    forecast shows 72- and 96-hour remnant low points to indicate the
    expected track over Central America, but it is highly likely that
    the center will have dissipated by those times.


    Key Messages:

    1. Julia is forecast to strengthen into a hurricane by Saturday
    evening while it moves over the southwestern Caribbean Sea, and a
    Hurricane Warning is now in effect for San Andres, Providencia, and
    Santa Catalina Islands. A Hurricane Watch is also now in effect for
    much of the Nicaragua coast. Hurricane-force winds and a dangerous
    storm surge are expected in areas where the core of the system
    crosses the islands and moves onshore.

    2. The risk of flash flooding continues today over portions of the
    Guajira Peninsula. The potential for life-threatening flash flooding
    and mudslides is expected to spread to portions of Central America
    this weekend.


    FORECAST POSITIONS AND MAX WINDS

    INIT 07/1500Z 12.7N 73.1W 35 KT 40 MPH
    12H 08/0000Z 13.0N 75.5W 45 KT 50 MPH
    24H 08/1200Z 13.2N 78.7W 55 KT 65 MPH
    36H 09/0000Z 13.1N 81.3W 65 KT 75 MPH
    48H 09/1200Z 13.1N 83.6W 75 KT 85 MPH...INLAND
    60H 10/0000Z 13.6N 85.9W 45 KT 50 MPH...INLAND
    72H 10/1200Z 14.5N 88.5W 30 KT 35 MPH...POST-TROP/INLAND
    96H 11/1200Z 16.2N 93.5W 25 KT 30 MPH...POST-TROP/INLAND
    120H 12/1200Z...DISSIPATED

    $$
    Forecaster Berg


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    • Like 1
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