Disclaimer:  This site is not affiliated with the National Hurricane Center, Hurricane Hunters, Storm Prediction Center, or National Weather Service.  ALL forecasts herein are the result of my analysis, (to which you will see me at times, insert excerpts from various agencies due to the nature of the importance of the information) and I am solely responsible for the content.  As ALWAYS, follow the National Hurricane Center, National Weather Service, and your local Emergency Management officials for emergency decisions.  In addition, this is strictly a FORECAST OFFICE.  I CANNOT make decisions regarding travel plans, etc.  My purpose, is to provide you the information, based solely on information I analyze, and the accuracy of the information at hand of the time of analysis, so you may make informed decisions.
(T. F. “Storm” Walsh)

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I will reiterate, my forecasts are based on the available information at the time of analysis, and are only as accurate as the information analyzed and the solutions provided.

Good day everyone!
I will be out of the office from NOV. 22 through the end of the month, as we will be traveling to spend the Thanksgiving holiday with family.  I should be back on DEC. 01 to resume forecasting, but will once again be out of the office OOA Dec. 3 – 4 to travel to Gainesville as my wife is having a minor outpatient surgical procedure. 

The Storm Prediction Center (SPC) has issued a MARGINAL risk for severe thunderstorms in the current DAY 1 Outlook: ACROSS PARTS OF THE LOWER OHIO VALLEY…

…SPC SUMMARY…
Isolated strong to severe storms are possible across parts of the lower Ohio Valley region today.
SPC DAY 1 SEVERE THUNDERSTORM OUTLOOK (LINKED FOR OUTLOOK TEXT)

TORNADO PROBABILITY

Probability of a tornado within 25 miles of a point.
HAIL PROBABILITY

Probability of one inch diameter hail or larger within 25 miles of a point.
DAMAGING THUNDERSTORM WIND PROBABILITY

Probability of damaging thunderstorm winds or wind gusts of 50 knots or higher within 25 miles of a point.
The following is the current CSU – MLP severe weather forecast map:
CSU – MLP DAY 1 FORECAST (CLICK FOR LARGER IMAGE)


DAY 1 PROBABILITY CONVERSION TABLE

SPC DISCUSSION EXCERPT: 
…Mid Mississippi/Lower Ohio Valley…
Elevated thunderstorms ongoing this morning across the mid MS/lower OH Valley are being aided by a southwesterly low-level jet and related warm/moist advection. This activity may pose an isolated hail threat as it tracks eastward this morning across the lower OH Valley before eventually encountering a less unstable airmass. A mid-level shortwave trough will advance eastward across the Midwest/mid MS Valley into the OH Valley through this evening. A weak surface low attendant to this shortwave trough will likewise develop east-southeastward across MO into the lower OH Valley while gradually weakening. Low-level moisture will return northward across this region ahead of a east-southeastward advancing cold front.

Current expectations are for some re-intensification of convection to occur this afternoon across the southern IL/western KY vicinity as strong ascent associated with the shortwave trough overspreads this region. There is still some uncertainty with how far north the surface warm sector will be able to advance, and daytime heating may be muted by persistent cloudiness. But, the best combination of weak to locally moderate instability and favorable deep-layer shear should overlap across the mid MS/lower OH Valley this afternoon and evening as a 50-60+ kt westerly mid-level jet moves across these areas. Any sustained supercell may be capable of producing severe hail along with locally damaging winds, with elevated convection possible north of the warm front into central IL/southern IN. Some threat for a tornado or two may also exist if sufficient boundary-layer instability can advance far enough northward in tandem with the warm front and enhanced low-level shear to support surface-based thunderstorms. No changes have been made to the Marginal Risk with this update. Confidence in a more concentrated corridor of severe risk was not high enough to include greater severe probabilities at this time, but trends will be monitored.

The following maps are tornado and significant tornado probabilities from NADOCAST. Current SIGTOR is <1%:
12Z NADOCAST TORNADO PROBABILITY (CLICK FOR LARGER IMAGE)

12Z NADOCAST SIGTOR PROBABILITY (CLICK FOR LARGER IMAGE)

The SPC has introduced a low tornado risk.  Although storms initiated earlier this morning, SPC indicates some re-intensification could occur this afternoon.  The CIPS Deterministic model I use mainly to analyze forecast indices is down.  However based on various information from the NAM 3 km model, the atmosphere over the outlook area is somewhat stable based on CAPE less than 100 j/kg, normal Lapse Rates and lifted indices of 3 to -1.  I know this raises the question of how could tornado activity possibly occur?  Based on research, this is possible given the 50 – 60 kt bulk wind shear, along with the probability of the rain cooled air from the earlier storms, and LCL (Lifted Condensation Level) being low (less than 500 meters), along with SRH running between 300 – 500 m2-m2.  The following is from an online article:
Mechanisms for Tornadoes in Low-Instability Environments:
Strong Low-Level Wind Shear: Wind shear (a change in wind speed and/or direction with height) is a critical ingredient for tornado formation. Even with weak instability (normal lapse rates and weak lifted indices), significant low-level wind shear can create horizontal spinning air currents (horizontal vorticity) near the ground. When a thunderstorm updraft moves over this horizontally spinning air, it can tilt the rotation vertically, forming a tornado.

Non-Supercell Tornadoes (Landspouts/Waterspouts): These types of tornadoes often form along pre-existing surface boundaries (like convergence lines or outflow boundaries from previous storms) where there is already some weak, localized rotation. The updraft of a developing, non-rotating (or weakly rotating) thunderstorm can then stretch this existing vertical rotation, rapidly intensifying the spin into a tornado, even in environments that lack the high Convective Available Potential Energy (CAPE) or steep lapse rates typical of supercells.

Dynamic Instabilities and Forcing: In some cases, dynamic processes play a more important role than the release of latent heat (instability). Forcing mechanisms, such as strong lift along a front or a vigorous cold pool (rain-cooled air) interaction with warm, moist air ahead of it, can create a powerful, localized updraft that generates a tornado without a traditional, deep-layer unstable atmosphere.

Low-Level Moisture and CAPE: While deep-layer CAPE might be weak, adequate low-level moisture can still create sufficient low-level instability (0-3 km CAPE) to support tornadogenesis. This low-level instability, combined with strong shear, helps maintain the strong vertical velocities near the surface needed to stretch the rotating column of air into a tornado.

Low LCL Heights: A low Lifted Condensation Level (LCL), which means the cloud base is closer to the ground, is often associated with a higher likelihood of tornadoes. This proximity allows the low-level rotation to be more effectively drawn into the storm’s main updraft and concentrated at the surface.

SIGNIFICANT RIVER FLOOD OUTLOOK
https://www.wpc.ncep.noaa.gov/nationalfloodoutlook/index.html

The following NWS Watch / Warning map will provide local NWS information for your area.  Click the image, then once it refreshes, click on your area of interest to view any special weather statements, hazards or advisories for your area.
NWS WATCH / WARNING DISPLAY (LINKED…CLICK MAP, THEN YOUR AREA)

NWS DOPPLER RADAR LOOP (LINKED, CLICK RADAR MAP)

RAP RADAR (CLICK IMAGE THEN GO TO LOOP DURATION AND PICK LENGTH OF LOOP, THEN CLICK RADAR SITE)
CARIBBEAN RADAR (CLICK IMAGE TO ACCESS ANIMATION)

You may direct any questions by contacting me personally, ANYTIME, at: [email protected]

Have a blessed day!

T. F. “STORM” WALSH III
GMCS, USCG (ret)
METEOROLOGIST / HURRICANE SPECIALIST /SEVERE WEATHER SPECIALIST