top of page

20240411 PNM

Updated: Apr 11

List of updates:

  1. Initial 20240411 PNM (6 am on Tues, 9 April )

  2. Update No. 2 (6 am on Wed, 10 April)

  3. Update No. 3 (3 pm on Wed, 10 April)

  4. Update No. 4 (4 pm on Wed, 10 April)

  5. Update No. 5 (6 am on Thurs, 11 April)

  6. Update No. 6 (2 pm on Thurs, 11 April)


- - - - - - - - - - -


Update No. 6 (2 pm on Thursday, 11 April 2024)


Summary of changes: Increased concerns for flooding (to include at risk areas of Clinton County). Concern continues for high winds for Friday, with gusts ranging from 30-40 mph for our county. Tornado risk for Clinton County remains at 2%-4%, as is the potential for large hail.



Updated NWS ILN weather briefing graphics:









[END]


- - - - - - - - - - -


Update No. 5 (6 am on Thursday, 11 April 2024)


Summary of Changes from prior briefing: Decrease in tornado and damaging winds risk. Timing delayed by 1 hour. Timing for arrival delayed to between 2-4 pm.


  • Isolated severe risk continues this evening along the northeast Gulf Coast. Locally damaging winds are the primary threat, though a tornado can not be ruled out.



Updated NWS slides:








Updated SPC DAY 1 (Thurs) Categorical Outlook:



Updated SPC DAY 1 (Thurs) Tornado Outlook:



Updated SPC DAY 1 (Thurs) Hail Outlook:



Updated SPC DAY (Thurs) Wind Outlook:


[END]


- - - - - - - - - - -


Update No. 4 (4 pm on Wednesday, 10 April 2024)


Summary of Changes: NWS posted weather briefing to communicate threats and timelines for forecasted weather for Thursday, 11 April 2024. Brief updated here (LINK). Clinton County primary threats include:

  • Potential for damaging winds;

  • 2%-4% risk for Tornado;

  • Large Hail;

  • Power outage due to downed trees and powerlines;

  • Friday: Wind gusts between 30 and 40 mph.


NWS posted slides:







[END]


- - - - - - - - - - -


Update No. 3 (3:00 pm on Wednesday, 10 April 2024)


Summary of Changes: No change ... SLIGHT & 2%-4% Tornado Risk maintained for Clinton County. Increased threats materializing to SE & E Ohio (ENHANCED & 10% Tornado Risk). If heading to Chillicothe, Athens, or near the PA/WX border area, remain weather aware!


Recommendations remain the same:

  • Review your household & business disaster plan. Make updates based on prior events or changes to your situation.

  • If you are not signed up for emergency alerts, do so now (LINK).

  • If you, or a member of your family, is reliant on electrically powered medical devices, review and prepare your power outage plan. Also, ensure you are registered with your power provider.


SPC Day 2 Convective Risk showing increased risk to SE & E Ohio region:



No major change to SPC Day 2 Tornado Risk for Clinton County (remains 2%-4%).


[END]


- - - - - - - - - - -


Update No. 2 (6:00 am on Wednesday, 10 April 2024)


Changes: Hazards primarily consist of strong winds, with a possibility of tornadoes and isolated large hail. The region most at risk for severe storms is northern and northeast Kentucky extending into the Scioto Valley in Ohio. Wind gusts are expected to begin shortly after 3 am and persist into Thursday evening.


Risk: SLIGHT (2 on a scale of 5)

  • MARGINAL - Isolated severe thunderstorms possible; limited in duration and/or coverage and/or intensity.

  • SLIGHT - Scattered severe storms possible; short-lived and/or not widespread. Isolated intense storms possible.

  • ENHANCED- Numerous severe storms possible; more persistent and/or widespread, a few intense.

  • MODERATE - Widespread severe storms likely; long-lived, widespread and intense.

  • HIGH - Widespread severe storms expected; long-lived, very widespread and particularly intense.


Tornado Risk: 2% (probability of a tornado within 25 miles of a point).

  • Very low threat to life and property.

  • Preparations should be made for a very low likelihood (or 2% to 4% probability) of tornadoes; isolated tornadoes of F0 to F1 intensity possible.

  • The potential for isolated locations to experience minor to moderate tornado damage.


Note: By a large majority, F0 & F1 tornadoes occur more often than F2 to F5 tornadoes.


F0 Tornado Damage - Minor tornado damage; damage to chimneys, a few downed trees and power lines, large signs blown over, damaged porches and screen houses, and damaged lighter-weight outbuildings. Tornado wind speeds of 73 mph or less.


F1 Tornado Damage - Moderate tornado damage; mobile homes moved off foundations or overturned, roof surfaces peeled off buildings, cars blown off roads, several large trees downed and some power outages. Tornado wind speeds of 74 mph to 112 mph.



NWS ILN issued OnePager for Thursday:



NWS Hazardous Weather Outlook:


.DAYS TWO THROUGH SEVEN...

Thursday through Tuesday.

Isolated to scattered severe storms may develop Thursday. Additionally, a continued threat for localized flooding is expected with multiple rounds of showers and thunderstorms. Wind gusts of 40 MPH+ are expected Friday.


.SPOTTER INFORMATION STATEMENT...

Spotter activation may be needed Thursday.



SPC Day 2 Tornado Outlook (2% for Clinton County):


Discussion:

ACUS02 KWNS 100553

SWODY2

SPC AC 100551

Day 2 Convective Outlook

NWS Storm Prediction Center Norman OK

1251 AM CDT Wed Apr 10 2024

Valid 111200Z - 121200Z


...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS IN THE UPPER OH VALLEY AND PARTS OF THE SOUTHEAST...


...SUMMARY...

Severe thunderstorms with a few tornadoes, scattered damaging winds, and isolated large hail are likely across the Upper Ohio Valley vicinity, mainly during Thursday afternoon. Scattered damaging winds and a few tornadoes will also be possible across southeast Georgia into central Florida, from Thursday morning into the afternoon.


...Synopsis...

A full-latitude mid/upper trough will be centered near the MS Valley at 12Z Thursday, comprised of two primary shortwave impulses. The southern-stream impulse should pivot northeast and accelerate as the northern-stream impulse becomes the dominant embedded feature. A steadily deepening surface cyclone will track northeast from the Lower OH Valley to the Lake Huron vicinity during the period.


...Upper OH Valley...

A synoptically favorable corridor for a few supercells and organized clustering into short-line segments appears likely to develop east of the gradually deepening surface cyclone track. This region should have a period where an overspreading mid-level dry slot coincides with the diurnal heating cycle, before afternoon convection develops within the left-exit region of the strong mid-level jet across the Southeast and southern Appalachians. MLCAPE should reach 500-1000 J/kg amid a meridional supercell wind profile, before low-level flow becomes veered from the southwest. Consensus of 00Z CAM guidance supports the potential for a few supercells, with some upscale growth into a line segment as convection consolidates northeastward. This may be relatively short-lived as convection outpaces the weak buoyancy plume and likely weakens after dusk. A mesoscale corridor of greater severe probabilities, seemingly in the form of damaging wind, may be warranted in later outlooks.



NWS weather graph data (showing 6 pm Wed through 6 pm on Friday):


[END]


- - - - - - - - - - -


Initial Posting: 9 April 2024


This is your initial Prepare Now Message (PNM) for potential severe weather for this Thursday, 11 April 2024.


The Storm Prediction Center (SPC) has issued a Day 3 Categorical Outlook that shows Clinton County at a SLIGHT risk for severe weather. SLIGHT risk notes "Scattered severe storms possible ... short-lived and/or not widespread, isolated intense storms possible." Finally, An area of organized severe storms, which is not widespread in coverage with varying levels of intensity. Click HERE for more information on risk categories used by NWS.



Recommendations:

  • Review your household & business disaster plan. Make updates based on prior events or changes to your situation.

  • If you are not signed up for emergency alerts, do so now (LINK).

  • If you, or a member of your family, is reliant on electrically powered medical devices, review and prepare your power outage plan. Also, ensure you are registered with your power provider.


If you are an AES customer, you can update your account (see image below from the FAQ section ... currently the fifth question from the bottom).


If you are an Duke Energy customer, they have a similar program that you will have to complete through their customer service. Below is from the FAQ page and at this time is the fourth question listed:


  • Otherwise, review and consider actions associated with keywords SEVERE, POWER and TORNADO at cc-ema.org/prepare



SPC Day 3 predictions:


Regional view of SPC Day 3 prediction:


SPC Day 3 Convective Outlook Discussion:


Day 3 Convective Outlook

NWS Storm Prediction Center Norman OK

0226 AM CDT Tue Apr 09 2024

Valid 111200Z - 121200Z


...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS IN PARTS OF THE SOUTHEAST AND THE UPPER OH VALLEY...


...SUMMARY...


Scattered severe thunderstorms are possible on Thursday across parts of the Southeast and the Upper Ohio Valley.


...Synopsis...


A full-latitude mid/upper trough should be centered near the MS Valley at 12Z Thursday, comprised of two primary shortwave impulses. The southern-stream impulse should pivot northeast and accelerate as the northern-stream impulse becomes the dominant embedded feature. A steadily deepening surface cyclone should track northeast from the Lower OH Valley to the Lake Huron vicinity during the period.


...Southeast...


A convective swath should be ongoing from parts of the FL Panhandle into GA on Thursday morning. The southern portion of this activity will have the best chance to maintain a damaging wind and embedded tornado threat from late morning into the early afternoon as stronger boundary-layer heating occurs across FL. Large-scale ascent will weaken with southern extent through the day given the northeastward track of the surface cyclone, in addition to low-level winds becoming more veered in time over the FL Peninsula. Farther north, fast 850-700 mb winds should be coincident with a plume of mid to upper 60s advecting north into the Carolinas. However, diabatic surface heating may be quite limited by abundant downstream cloudiness/stratiform rain north of the deeper convection in FL. Mid-level lapse rates will also be weak and overall instability may remain meager. Still, the high-shear/low-CAPE setup with at least low-topped convection likely persisting until it progresses off the coast will foster some threat for sporadic damaging winds and a few brief tornadoes, mainly midday through early evening. How far north and how long the severe threat persists into Thursday night is unclear, but low probabilities appear warranted through at least the Lower Mid-Atlantic States.


...Upper OH Valley...


A synoptically favorable corridor for a few supercells and organized clusters should develop east of the gradually deepening surface cyclone track. This region should have a period where an overspreading mid-level dry slot coincides with the diurnal heating cycle, before early afternoon convection develops within the left-exit region of the strong mid-level jet across the Southeast and southern Appalachians. While MLCAPE will remain weak, a meridional supercell wind profile should be present before low-level flow becomes veered from the southwest. A couple tornadoes, isolated to scattered damaging winds, and isolated severe hail are possible.


..Grams.. 04/09/2024


[END]

1,154 views0 comments

Recent Posts

See All

Comentários


bottom of page